46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

46 CFR 59.20-1 - Carbon-steel or alloy-steel castings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... BOILERS, PRESSURE VESSELS AND APPURTENANCES Welding Repairs to Castings § 59.20-1 Carbon-steel or alloy-steel castings. Defects in carbon-steel or alloy-steel castings may be repaired by welding. The repairs...

A Short Study of Large Rotary Forged Cylinders

DTIC Science & Technology

1979-06-01

ESR Steel Hollow ESR Steel Rotary Forge Vacuum Degassed Steel 20. ABSTRACT (Continue on reverse aide It necessary and identity by block number...treatment rging Line was used to produce steel for the Advanced ocram. Cylinders were rotary forged from cast hollow ESR ssed steel . Anomalies in the data...prompted a more detailed The results are presented. Satisfactory properties were cuum degassed steel . However, the very light forging th the very

Argon Bubble Transport and Capture in Continuous Casting with an External Magnetic Field Using GPU-Based Large Eddy Simulations

NASA Astrophysics Data System (ADS)

Jin, Kai

Continuous casting produces over 95% of steel in the world today, hence even small improvements to this important industrial process can have large economic impact. In the continuous casting of steel process, argon gas is usually injected at the slide gate or stopper rod to prevent clogging, but entrapped bubbles may cause defects in the final product. Many defects in this process are related to the transient fluid flow in the mold region of the caster. Electromagnetic braking (EMBr) device is often used at high casting speed to modify the mold flow, reduce the surface velocity and fluctuation. This work studies the physics in continuous casting process including effects of EMBr on the motion of fluid flow in the mold region, and transport and capture of bubbles in the solidification processes. A computational effective Reynolds-averaged Navier-Stokes (RANS) model and a high fidelity Large Eddy Simulation (LES) model are used to understand the motion of the molten steel flow. A general purpose multi-GPU Navier-Stokes solver, CUFLOW, is developed. A Coherent-Structure Smagorinsky LES model is implemented to model the turbulent flow. A two-way coupled Lagrangian particle tracking model is added to track the motion of argon bubbles. A particle/bubble capture model based on force balance at dendrite tips is validated and used to study the capture of argon bubbles by the solidifying steel shell. To investigate the effects of EMBr on the turbulent molten steel flow and bubble transport, an electrical potential method is implemented to solve the magnetohydrodynamics equations. Volume of Fluid (VOF) simulations are carried out to understand the additional resistance force on moving argon bubbles caused by adding transverse magnetic field. A modified drag coefficient is extrapolated from the results and used in the two-way coupled Eulerian-Lagrangian model to predict the argon bubble transport in a caster with EMBr. A hook capture model is developed to understand the effects of hooks on argon bubble capture.

Modeling of Dendritic Evolution of Continuously Cast Steel Billet with Cellular Automaton

NASA Astrophysics Data System (ADS)

Wang, Weiling; Ji, Cheng; Luo, Sen; Zhu, Miaoyong

2018-02-01

In order to predict the dendritic evolution during the continuous steel casting process, a simple mechanism to connect the heat transfer at the macroscopic scale and the dendritic growth at the microscopic scale was proposed in the present work. As the core of the across-scale simulation, a two-dimensional cell automaton (CA) model with a decentered square algorithm was developed and parallelized. Apart from nucleation undercooling and probability, a temperature gradient was introduced to deal with the columnar-to-equiaxed transition (CET) by considering its variation during continuous casting. Based on the thermal history, the dendritic evolution in a 4 mm × 40 mm region near the centerline of a SWRH82B steel billet was predicted. The influences of the secondary cooling intensity, superheat, and casting speed on the dendritic structure of the billet were investigated in detail. The results show that the predicted equiaxed dendritic solidification of Fe-5.3Si alloy and columnar dendritic solidification of Fe-0.45C alloy are consistent with in situ experimental results [Yasuda et al. Int J Cast Metals Res 22:15-21 (2009); Yasuda et al. ISIJ Int 51:402-408 (2011)]. Moreover, the predicted dendritic arm spacing and CET location agree well with the actual results in the billet. The primary dendrite arm spacing of columnar dendrites decreases with increasing secondary cooling intensity, or decreasing superheat and casting speed. Meanwhile, the CET is promoted as the secondary cooling intensity and superheat decrease. However, the CET is not influenced by the casting speed, owing to the adjusting of the flow rate of secondary spray water. Compared with the superheat and casting speed, the secondary cooling intensity can influence the cooling rate and temperature gradient in deeper locations, and accordingly exerts a more significant influence on the equiaxed dendritic structure.

49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

Code of Federal Regulations, 2011 CFR

2011-10-01

..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... under this section. (b) Fracture control (1) The toughness properties for pipe must address the... specification level 2 or ASME B31.8 (incorporated by reference, see § 192.7). (2) Fracture control must: (i...

49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

Code of Federal Regulations, 2012 CFR

2012-10-01

..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... under this section. (b) Fracture control (1) The toughness properties for pipe must address the... specification level 2 or ASME B31.8 (incorporated by reference, see § 192.7). (2) Fracture control must: (i...

49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

Code of Federal Regulations, 2013 CFR

2013-10-01

..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... under this section. (b) Fracture control (1) The toughness properties for pipe must address the... specification level 2 or ASME B31.8 (incorporated by reference, see § 192.7). (2) Fracture control must: (i...

49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

Code of Federal Regulations, 2010 CFR

2010-10-01

..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... under this section. (b) Fracture control (1) The toughness properties for pipe must address the... specification level 2 or ASME B31.8 (incorporated by reference, see § 192.7). (2) Fracture control must: (i...

49 CFR 192.112 - Additional design requirements for steel pipe using alternative maximum allowable operating...

Code of Federal Regulations, 2014 CFR

2014-10-01

..., fully killed, continuously cast steel with calcium treatment. (2) The carbon equivalents of the steel... under this section. (b) Fracture control (1) The toughness properties for pipe must address the... specification level 2 or ASME B31.8 (incorporated by reference, see § 192.7). (2) Fracture control must: (i...

Effect of Rice Husk Ash Insulation Powder on the Reoxidation Behavior of Molten Steel in Continuous Casting Tundish

NASA Astrophysics Data System (ADS)

Kim, Tae Sung; Chung, Yongsug; Holappa, Lauri; Park, Joo Hyun

2017-06-01

Rice husk ash (RHA) has been widely used as an insulation powder in steel casting tundish. Its effect on the reoxidation of molten steel in tundish as well as on the corrosion of magnesia refractory was investigated. The reoxidation of the steel, indicated by an oxygen pickup, was progressed by increasing the ratio of RHA to the sum of RHA and carryover ladle slag ( R ratio) greater than about 0.2. The increase of the silica activity in the slag layer promoted the self-dissociation of SiO2 from the slag layer into the molten steel, resulting in the silicon and oxygen pickup as the R ratio increased. The total number of reoxidation inclusions dramatically increased and the relative fraction of Al2O3-rich inclusions increased by increasing the R ratio. Hence, the reoxidation of molten steel in tundish might become more serious due to the formation of alumina-rich inclusions as the casting sequence increases. MgO in the refractory directly dissolved into the molten slag layer without forming any intermediate compound layer ( e.g., spinel), which is a completely different situation from the general slag-refractory interfacial reaction. A flow was possibly induced by the bursting of gas bubbles at the ash-slag (-refractory) interface, since the silica in the RHA powder continuously dissolved into the molten slag pool. Thus, the RHA insulation powder has a negative effect on the corrosion of MgO refractory.

Modeling of Quasi-Four-Phase Flow in Continuous Casting Mold Using Hybrid Eulerian and Lagrangian Approach

NASA Astrophysics Data System (ADS)

Liu, Zhongqiu; Sun, Zhenbang; Li, Baokuan

2017-04-01

Lagrangian tracking model combined with Eulerian multi-phase model is employed to predict the time-dependent argon-steel-slag-air quasi-four-phase flow inside a slab continuous casting mold. The Eulerian approach is used for the description of three phases (molten steel, liquid slag, and air at the top of liquid slag layer). The dispersed argon bubble injected from the SEN is treated in the Lagrangian way. The complex interfacial momentum transfers between various phases are considered. Validation is supported by the measurement data of cold model experiments and industrial practice. Close agreements were achieved for the gas volume fraction, liquid flow pattern, level fluctuation, and exposed slag eye phenomena. Many known phenomena and new predictions were successfully reproduced using this model. The vortex slag entrapment phenomenon at the slag-steel interface was obtained using this model, some small slag drops are sucked deep into the liquid pool of molten steel. Varying gas flow rates have a large effect on the steel flow pattern in the upper recirculation zone. Three typical flow patterns inside the mold with different argon gas flow rates have been obtained: double roll, three roll, and single roll. Effects of argon gas flow rate, casting speed, and slag layer thickness on the exposed slag eye and level fluctuation at the slag-steel interface were studied. A dimensionless value of H ave/ h was proposed to describe the time-averaged level fluctuation of slag-steel interface. The exposed slag eye near the SEN would be formed when the value of H ave/ h is larger than 0.4.

Experimental and finite element study of ultimate strength of continuous composite concrete slabs with steel decking

NASA Astrophysics Data System (ADS)

Gholamhoseini, Alireza

2018-03-01

Composite one-way concrete slabs with profiled steel decking as permanent formwork are commonly used in the construction industry. The steel decking supports the wet concrete of a cast in situ reinforced or post-tensioned concrete slab and, after the concrete sets, acts as external reinforcement. In this type of slab, longitudinal shear failure between the concrete and the steel decking is the most common type of failure at the ultimate load stage. Design codes require the experimental evaluation of the ultimate load capacity and longitudinal shear strength of each type of steel decking using full-scale tests on simple-span slabs. There is also no procedure in current design codes to evaluate the ultimate load capacity and longitudinal shear strength of continuous composite slabs and this is often assessed experimentally by full-scale tests. This paper presents the results of three full-scale tests up to failure on continuous composite concrete slabs cast with trapezoidal steel decking profile (KF70) that is widely used in Australia. Slab specimens were tested in four-point bending at each span with shear spans of span/4. The longitudinal shear failure of each slab is evaluated and the measured mid-span deflection, the end slip and the mid-span steel and concrete strains are also presented and discussed. Redistribution of bending moment in each slab is presented and discussed. A finite element model is proposed and verified by experimental data using interface element to model the bond properties between steel decking and concrete slab and investigate the ultimate strength of continuous composite concrete slabs.

Control of Low Melting Point Mno-Sio2-Al2o3 Inclusions in Low Carbon Thin-Strip Continuous Casting Steel

NASA Astrophysics Data System (ADS)

Chen, Jing; Zhu, Qing; Huang, Di; Zheng, Shaobo; Zhang, Jieyu; Li, Huigai

2017-09-01

There is a significant difference in the demand for molten steel quality between thin-strip continuous casting and traditional continuous casting. In order to make sure the better surface quality of the thin strips, to generate an oxidation film on the surface of cooling roller is required. This will require that the higher oxygen potential in molten steel and inclusions with low melting point. In this article, the possibility of producing low-melting inclusions which is mainly consisted of SiO2 and MnO is studied by controlling the initial oxygen potential and addition order of deoxidizing alloys. The interaction activity between each component in the ternary system of Al2O3-SiO2-MnO is obtained by Action Concentration model. The equal [Mn], [Si], [O], [Al] curve under the temperature of 1823K and equilibrium condition in ternary system of Al2O3-SiO2-MnO is obtained by relative thermodynamic calculation as well. The control method for getting the low-melting point inclusion is as below. While the weight percentage of Si is 0.35% and the one of Mn is 0.90%, in order to maintain the melting point of inclusion around 1200°C, the free oxygen potential in melted steel F[O] should be maintained between 0.002% ∼ 0.004%. On the contrary, the requirement for acid dissolved [Al] content in melted steel is as low as 0.0001% ∼ 0.0005%.

AIS/DOE Technology Roadmap Program: Strip Casting: Anticipating New Routes To Steel Sheet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prof. Alan W. Camb; Prof. Anthony Rollett

2001-08-31

To determine the potential for strip casting in the steel industry and to develop the fundamental knowledge necessary to allow the role of strip casting in the modern steel industry to be understood. Based upon a study of carbon steel strip castings that were either produced for the program at British Steel or were received from a pre-commercial production machine, the following conclusions were made. Strip casting of carbon steels is technically feasible for sheet material from slightly less than 1 mm thick to 3 mm thick, and, assuming that it is economically viable, it will be first applied inmore » carbon steel markets that do not require stringent surface quality or extensive forming. The potential of strip casting as a casting process to be developed for steel castings is very high as the cast strip has some very novel characteristics. Direct cast carbon strip has better surface quality, shape and profile than any other casting process currently available. The more rapidly solidified structure of direct cast strip tends to be strong with low ductility; however, with adequate thermal treatment, it is possible to develop a variety of properties from the same grade. The process is more amenable at this time to production tonnages per year of the order of 500,000 tons and as such will first find niche type applications. This technology is an additional technology for steel production and will be in addition to, rather than a replacement for, current casting machines.« less

Mineral resource of the month: manganese

USGS Publications Warehouse

Corathers, Lisa A.

2012-01-01

Manganese is a silver-colored metal resembling iron and often found in conjunction with iron. The earliest-known human use of manganese compounds was in the Stone Age, when early humans used manganese dioxide as pigments in cave paintings. In ancient Rome and Egypt, people started using it to color or remove the color from glass - a practice that continued to modern times. Today, manganese is predominantly used in metallurgical applications as an alloying addition, particularly in steel and cast iron production. Steel and cast iron together provide the largest market for manganese (historically 85 to 90 percent), but it is also alloyed with nonferrous metals such as aluminum and copper. Its importance to steel cannot be overstated, as almost all types of steel contain manganese and could not exist without it.

Interlocking multi-material components made of structured steel sheets and high-pressure die cast aluminium

NASA Astrophysics Data System (ADS)

Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.

2017-10-01

Lightweight design is a major driving force of innovation, especially in the automotive industry. Using hybrid components made of two or more different materials is one approach to reduce the vehicles weight and decrease fuel consumption. As a possible way to increase the stiffness of multi-material components, this paper presents a process chain to produce such components made of steel sheets and high-pressure die cast aluminium. Prior to the casting sequence the steel sheets are structured in a modified rolling process which enables continuous interlocking with the aluminium. Two structures manufactured by this rolling process are tested. The first one is a channel like structure and the second one is a channel like structure with undercuts. These undercuts enable the formation of small anchors when the molten aluminium fills them. The correlation between thickness reduction during rolling and the shape of the resulting structure was evaluated for both structures. It can be stated that channels with a depth of up to 0.5 mm and a width of 1 mm could be created. Undercuts with different size depending on the thickness reduction could be realised. Subsequent aluminium high-pressure die casting experiments were performed to determine if the surface structure can be filled gap-free with molten aluminium during the casting sequence and if a gap-free connection can be achieved after contraction of the aluminium. The casting experiments showed that both structures could be filled during the high-pressure die casting. The channel like structure results in a gap between steel and aluminium after contraction of the cast metal whereas the structure with undercuts leads to a good interlocking resulting in a gap-free connection.

41. PHOTOGRAPHY OF BLUE PRINT (MINNEAPOLIS CITY ENGINEER) END AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

41. PHOTOGRAPHY OF BLUE PRINT (MINNEAPOLIS CITY ENGINEER) END AND CENTRE CASTING OF CAST STEEL, MASONRY CASTING OF CAST IRON CASTING, FOR MINNEAPOLIS STEEL ARCH (4 x 5 negative) - Steel Arch Bridge, Hennepin Avenue spanning west channel of Mississippi River, Minneapolis, Hennepin County, MN

Phase-field modelling of microstructure formation during the solidification of continuously cast low carbon and HSLA steels

NASA Astrophysics Data System (ADS)

Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

2012-07-01

Cracking in continuous casting of steels has been one of the main problems for decades. Many of the cracks that occur during solidification are hot tears. To better understand the factors leading to this defect, microstructure formation is simulated for a low carbon (LCAK) and two high strength low alloyed (HSLA) steel grades during the initial stage of the process where the first solidified shell is formed inside the mould and where breakouts typically occur. 2D simulation is performed using the multiphase-field software MICRESS [1], which is coupled to the thermodynamic database TCFE6 [2] and the mobility database MOB2 [2], taking into account all elements which may have a relevant effect on the mechanical properties and structure formation during or subsequent to solidification. The use of a moving-frame boundary condition allows travelling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. A heterogeneous nucleation model is included to permit the description of morphological transitions between the initial solidification and the subsequent columnar growth region. Furthermore, a macroscopic one-dimensional temperature solver is integrated to account for the transient and nonlinear temperature field during the initial stage of continuous casting. The external heat flux boundary conditions for this process were derived from thermal process data of the industrial slab caster. The simulation results for the three steel grades have been validated by thickness measurements of breakout shells and microstructure observation of the corresponding grades. Furthermore, the primary dendrite spacing has been measured across the whole thickness of the shell and compared with the simulated microstructures. Significant microstructure differences between the steel grades are discussed and correlated with their hot-cracking behavior.

Twin-belt continuous caster with containment and cooling of the exiting cast product for enabling high-speed casting of molten-center product

DOEpatents

Dykes, Charles D.; Daniel, Sabah S.; Wood, J. F. Barry

1990-02-20

In continuously casting molten metal into cast product by a twin-belt machine, it is desirable to achieve dramatic increases in speed (linear feet per minute) at which cast product exits the machine, particularly in installations where steel cast product is intended to feed a downstream regular rolling mill (as distinct from a planetary mill) operating in tandem with the twin-belt caster. Such high-speed casting produces product with a relatively thin shell and molten interior, and the shell tends to bulge outwardly due to metallostatic head pressure of the molten center. A number of cooperative features enable high-speed, twin-belt casting: (1) Each casting belt is slidably supported adjacent to the caster exit pulley for bulge control and enhanced cooling of cast product. (2) Lateral skew steering of each belt provides an effective increase in moving mold length plus a continuity of heat transfer not obtained with prior art belt steering apparatus. (3) The exiting slab is contained and supported downstream from the casting machine to prevent bulging of the shell of the cast product, and (4) spray cooling is incorporated in the exit containment apparatus for secondary cooling of cast product.

INTERIOR OVERVIEW OF CONTINUOUS CASTER WITH NO. 12 LADLE. MOLTEN ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

INTERIOR OVERVIEW OF CONTINUOUS CASTER WITH NO. 12 LADLE. MOLTEN STEEL IS POURED FROM LADLE THROUGH SHROUD TO TUNDISH. FROM TUNDISH STEEL ENTERS MOLD THROUGH SHROUD AND FORMATION OF SLAB SHELL BEGINS. AS SLAB PROGRESSES THROUGH CONTAINMENT SECTION IT IS COOLED WITH AIR MIST SPRAYS AND CONTINUES SOLIDIFICATION. UPON EXITING THE MACHINE THE SLABS ARE CUT TO DESIRED LENGTH AND IDENTIFIED. THE SLABS ARE STACKED, REMOVED FROM MACHINE AND PREPARED FOR SHIPMENT TO HOT STRIP MILL. CASTER HAS ABILITY TO PRODUCE SINGLE OR TWIN CASTS. SINGLE SLABS PRODUCED MAY BE UP TO 102 INCHES; DOUBLE SLABS UP TO 49 INCHES. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

MULTIPLE SETS OF TWIN SLABS ON THE RUN OUT. THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MULTIPLE SETS OF TWIN SLABS ON THE RUN OUT. THE RUN OUT INCLUDES THE TRAVELING TORCH WHICH CUTS SLABS TO DESIRED LENGTH, AN IDENTIFICATION SYSTEM TO INDICATE HEAT NUMBER AND TRACE IDENTITY OF EVERY SLAB, AND A DEBURRING DEVICE TO SMOOTH SLABS. AT LEFT OF ROLLS IS THE DUMMY BAR. DUMMY BAR IS INSERTED UP THROUGH CONTAINMENT SECTION INTO MOLD PRIOR TO START OF CAST. WHEN STEEL IS INTRODUCED INTO MOLD IT CONNECTS WITH BAR AS CAST BEGINS, AT RUN OUT DUMMY BAR DISCONNECTS AND IS STORED. - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

MULTIPLE SETS OF TWIN SLABS ON THE RUN OUT. THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

MULTIPLE SETS OF TWIN SLABS ON THE RUN OUT. THE RUN OUT INCLUDES THE TRAVELING TORCH WHICH CUTS SLABS TO DESIRED LENGTH, AN IDENTIFICATION SYSTEM TO INDICATE HEAT NUMBER AND TRACE IDENTITY OF EVERY SLAB, AND A DEBURRING DEVICE TO SMOOTH SLABS. AT LEFT OF ROLLS IS THE DUMMY BAR. DUMMY BAR IS INSERTED UP THROUGH CONTAINMENT SECTION INTO MOLD PRIOR TO START OF CAST. WHEN STEEL IS INTRODUCED INTO MOLD IT CONNECTS WITH BAR AS CAST BEGINS, AT RUN OUT DUMMY BAR DISCONNECTS AND IS STORED - U.S. Steel, Fairfield Works, Continuous Caster, Fairfield, Jefferson County, AL

40 CFR 420.67 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true [Reserved] 420.67 Section 420.67 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.67 [Reserved] ...

40 CFR 420.61 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true [Reserved] 420.61 Section 420.61 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory § 420.61 [Reserved] ...

Mold Flux Crystallization and Mold Thermal Behavior

NASA Astrophysics Data System (ADS)

Peterson, Elizabeth Irene

Mold flux plays a small but critical role in the continuous casting of steel. The carbon-coated powder is added at the top of the water-cooled copper mold, over time it melts and infiltrates the gap between the copper mold and the solidifying steel strand. Mold powders serve five primary functions: (1) chemical insulation, (2) thermal insulation, (3) lubrication between the steel strand and mold, (4) absorption of inclusions, and (5) promotion of even heat flux. All five functions are critical to slab casting, but surface defect prevention is primarily controlled through even heat flux. Glassy fluxes have high heat transfer and result in a thicker steel shell. Steels with large volumetric shrinkage on cooling must have a crystalline flux to reduce the radiative heat transfer and avoid the formation of cracks in the shell. Crystallinity plays a critical role in steel shell formation, therefore it is important to study the thermal conditions that promote each phase and its morphology. Laboratory tests were performed to generate continuous cooling transformation (CCT) and time-temperature-transformation (TTT) diagrams. Continuous cooling transformation tests were performed in an instrumented eight cell step chill mold. Results showed that cuspidine was the only phase formed in conventional fluxes and all observed structures were dendritic. An isothermal tin bath quench method was also developed to isothermally age glassy samples. Isothermal tests yielded different microstructures and different phases than those observed by continuous cooling. Comparison of aged tests with industrial flux films indicates similar faceted structures along the mold wall, suggesting that mold flux first solidifies as a glass along the mold wall, but the elevated temperature devitrifies the glassy structure forming crystals that cannot form by continuous cooling.

On the formation of fold-type oscillation marks in the continuous casting of steel.

PubMed

Vynnycky, M; Saleem, S; Devine, K M; Florio, B J; Mitchell, S L; O'Brien, S B G

2017-06-01

Asymptotic methods are employed to revisit an earlier model for oscillation-mark formation in the continuous casting of steel. A systematic non-dimensionalization of the governing equations, which was not carried out previously, leads to a model with 12 dimensionless parameters. Analysis is provided in the same parameter regime as for the earlier model, and surprisingly simple analytical solutions are found for the oscillation-mark profiles; these are found to agree reasonably well with the numerical solution in the earlier model and very well with fold-type oscillation marks that have been obtained in more recent experimental work. The benefits of this approach, when compared with time-consuming numerical simulations, are discussed in the context of auxiliary models for macrosegregation and thermomechanical stresses and strains.

On the formation of fold-type oscillation marks in the continuous casting of steel

PubMed Central

Saleem, S.; Devine, K. M.; Florio, B. J.; Mitchell, S. L.; O’Brien, S. B. G.

2017-01-01

Asymptotic methods are employed to revisit an earlier model for oscillation-mark formation in the continuous casting of steel. A systematic non-dimensionalization of the governing equations, which was not carried out previously, leads to a model with 12 dimensionless parameters. Analysis is provided in the same parameter regime as for the earlier model, and surprisingly simple analytical solutions are found for the oscillation-mark profiles; these are found to agree reasonably well with the numerical solution in the earlier model and very well with fold-type oscillation marks that have been obtained in more recent experimental work. The benefits of this approach, when compared with time-consuming numerical simulations, are discussed in the context of auxiliary models for macrosegregation and thermomechanical stresses and strains. PMID:28680666

Experimental study of the continuous casting slab solidification microstructure by the dendrite etching method

NASA Astrophysics Data System (ADS)

Yang, X. G.; Xu, Q. T.; Wu, C. L.; Chen, Y. S.

2017-12-01

The relationship between the microstructure of the continuous casting slab (CCS) and quality defects of the steel products, as well as evolution and characteristics of the fine equiaxed, columnar, equiaxed zones and crossed dendrites of CCS were systematically investigated in this study. Different microstructures of various CCS samples were revealed. The dendrite etching method was proved to be quite efficient for the analysis of solidified morphologies, which are essential to estimate the material characteristics, especially the CCS microstructure defects.

Development and Technology of Large Thickness TMCP Steel Plate with 390MPA Grade Used for Engineering Machinery

NASA Astrophysics Data System (ADS)

Wang, Xiaoshu; Zhang, Zhijun; Zhang, Peng

Recently, with the rapid upgrading of the equipment in the steel Corp, the rolling technology of TMCP has been rapidly developed and widely applied. A large amount of steel plate has been produced by using the TMCP technology. The TMCP processes have been used more and more widely and replaced the heat treatment technology of normalizing, quenching and tempering heat process. In this paper, low financial input is considered in steel plate production and the composition of the steel has been designed with low C component, a limited alloy element of the Nb, and certain amounts of Mn element. During the continuous casting process, the size of the continuous casting slab section is 300 mm × 2400 mm. The rolling technology of TMCP is controlled at a lower rolling and red temperature to control the transformation of the microstructure. Four different rolling treatments are chosen to test its effects on the 390MPa grade low carbon steel of bainitic microstructure and properties. This test manages to produce a proper steel plate fulfilling the standard mechanical properties. Specifically, low carbon bainite is observed in the microstructure of the steel plate and the maximum thickness of steel plate under this TMCP technology is up to 80mm. The mechanical property of the steel plate is excellent and the KV2 at -40 °C performs more than 200 J. Moreover, the production costs are greatly reduced when the steel plate is produced by this TMCP technology when replacing the current production process of quenching and tempering. The low cost steel plate could well meet the requirements of producing engineering machinery in the steel market.

Effect of Structure Factor on High-Temperature Ductility of Pipe Steels

NASA Astrophysics Data System (ADS)

Kolbasnikov, N. G.; Matveev, M. A.; Mishnev, P. A.

2016-05-01

Effects of various factors such as the grain size, the morphology of nonmetallic inclusions, and joint microalloying with boron and titanium on the high-temperature ductility of pipe steels are studied. Physical modeling of the conditions of cooling of the skin of a continuous-cast preform in the zone of secondary cooling in a Gleeble facility is performed. Technical recommendations are given for raising the hot ductility of steels under industrial conditions.

Long-term oxidation of candidate cast iron and stainless steel exhaust system alloys from 650 to 800 °C in air with water vapor

DOE PAGES

Brady, Michael P.; Muralidharan, Govindarajan; Leonard, Donovan .; ...

2014-08-29

Here, the oxidation behavior of SiMo cast iron, Ni-resist D 5S cast iron, cast chromia-forming austenitic stainless steels of varying Cr/Ni content based on CF8C plus, HK, and HP, and a developmental cast alumina-forming austenitic (AFA) stainless steel of interest for diesel exhaust system components were studied for up to 5000 h at 650-800 °C in air with 10% H 2O. At 650 °C, the Ni-resist D5S exhibited moderately better oxidation resistance than did the SiMo cast iron. However, the D5S suffered from oxide scale spallation issues at 700 °C and higher, whereas the oxide scales formed on SiMo castmore » iron remained adherent from 700-800 °C despite oxide scales hundreds of microns thick. The oxidation of the SiMo cast iron exhibited unusual temperature dependence, with periods of slower oxidation kinetics at 750-800 °C compared to 650-700 °C due to continuous silica-rich scale formation at the higher temperatures. The oxidation of the cast chromia-forming austenitics trended with the level of Cr and Ni additions, with small mass losses consistent with Cr oxy-hydroxide volatilization processes for the higher 25Cr/25-35Ni HK and HP type alloys, and transition to rapid Fe-base oxide formation and scale spallation in the lower 19Cr/12Ni CF8C plus type alloy. In contrast, small positive mass changes consistent with protective alumina scale formation were observed for the cast AFA alloy under all conditions studied. Implications of these findings for diesel exhaust system components are discussed.« less

40 CFR 420.64 - New source performance standards (NSPS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true New source performance standards (NSPS). 420.64 Section 420.64 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Continuous Casting Subcategory...

40 CFR 420.65 - Pretreatment standards for existing sources (PSES).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources (PSES). 420.65 Section 420.65 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Continuous Casting...

40 CFR 420.66 - Pretreatment standards for new sources (PSNS).

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources (PSNS). 420.66 Section 420.66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS IRON AND STEEL MANUFACTURING POINT SOURCE CATEGORY Continuous Casting...

Energy Saving Melting and Revert Reduction Technology (Energy SMARRT): Development of CCT Diagrams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chumbley, L Scott

2011-08-20

One of the most energy intensive industries in the U.S. today is in the melting and casting of steel alloys for use in our advanced technological society. While the majority of steel castings involve low or mild carbon steel for common construction materials, highly-alloyed steels constitute a critical component of many industries due to their excellent properties. However, as the amount of alloying additions increases, the problems associated with casting these materials also increases, resulting in a large waste of energy due to inefficiency and a lack of basic information concerning these often complicated alloy systems. Superaustenitic stainless steels constitutemore » a group of Fe-based alloys that are compositionally balanced to have a purely austenitic matrix and exhibit favorable pitting and crevice corrosion resistant properties and mechanical strength. However, intermetallic precipitates such as sigma (³) and Laves can form during casting or exposure to high-temperature processing, which degrade the corrosion and mechanical properties of the material. Knowledge of the times and temperatures at which these detrimental phases form is imperative if a company is to efficiently produce castings of high quality in the minimum amount of time, using the lowest amount of energy possible, while producing the least amount of material waste. Anecdotal evidence from company representatives revealed that large castings frequently had to be scrapped due to either lower than expected corrosion resistance or extremely low fracture toughness. It was suspected that these poor corrosion and / or mechanical properties were directly related to the type, amount, and location of various intermetallic phases that formed during either the cooling cycle of the castings or subsequent heat treatments. However, no reliable data existed concerning either the time-temperature-transformation (TTT) diagrams or the continuous-cooling-transformation (CCT) diagrams of the super-austenitics. The goal of this study was to accurately characterize the solid-solid phase transformations seen in cast superaustenitic stainless steels. Heat treatments were performed to understand the time and temperature ranges for intermetallic phase formations in alloys CN3MN and CK3McuN. Microstructures were characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy and wavelength dispersive spectroscopy (EDS, WDS). In this way TTT and CCT diagrams could be developed for the matrix of samples chosen. As this study consisted of basic research into the development of TTT and CCT diagrams as an aid to the US steel casting industry, there is no formal commercialization plan associated with this task other than presentations and publications via the Steel Founders Society of America to their members. The author is confident that the data contained in this report can be used by steel foundries to refine their casting procedures in such a way as to reduce the amount of waste produced and energy wasted by significantly reducing or eliminating the need for remelting or recasting of material due to unwanted, premature intermetallic formation. This development of high alloy steel CCT diagrams was predicted to result in an average energy savings of 0.05 trillion BTU's/year over a 10 year period (with full funding). With 65% of the proposed funding, current (2011) annual energy saving estimates, based on initial dissemination to the casting industry in 2011and market penetration of 97% by 2020, is 0.14 trillion BTU's/year. The reduction of scrap and improvement in casting yield will also result in a reduction of environmental emissions associated with the melting and pouring of the steel. The average annual estimate of CO2 reduction per year through 2020 is 0.003 Million Metric Tons of Carbon Equivalent (MM TCE)« less

Evolution of Non-metallic Inclusions and Precipitates in Oriented Silicon Steel

NASA Astrophysics Data System (ADS)

Luo, Yan; Yang, Wen; Ren, Qiang; Hu, Zhiyuan; Li, Ming; Zhang, Lifeng

2018-06-01

The evolution of inclusions in oriented silicon steel during the manufacturing process was carried out by chemical composition analysis, non-aqueous electrolytic corrosion, and thermodynamic calculation. The morphology, composition, and size of inclusions were analyzed introducing field emission scanning electron microscope. The oxides were mainly formed during the secondary refining, and the nitrides, sulfides, and compounds were formed during the solidification and cooling of steel in the processes of continuous casting and hot rolling.

Application of RNAMlet to surface defect identification of steels

NASA Astrophysics Data System (ADS)

Xu, Ke; Xu, Yang; Zhou, Peng; Wang, Lei

2018-06-01

As three main production lines of steels, continuous casting slabs, hot rolled steel plates and cold rolled steel strips have different surface appearances and are produced at different speeds of their production lines. Therefore, the algorithms for the surface defect identifications of the three steel products have different requirements for real-time and anti-interference. The existing algorithms cannot be adaptively applied to surface defect identification of the three steel products. A new method of adaptive multi-scale geometric analysis named RNAMlet was proposed. The idea of RNAMlet came from the non-symmetry anti-packing pattern representation model (NAM). The image is decomposed into a set of rectangular blocks asymmetrically according to gray value changes of image pixels. Then two-dimensional Haar wavelet transform is applied to all blocks. If the image background is complex, the number of blocks is large, and more details of the image are utilized. If the image background is simple, the number of blocks is small, and less computation time is needed. RNAMlet was tested with image samples of the three steel products, and compared with three classical methods of multi-scale geometric analysis, including Contourlet, Shearlet and Tetrolet. For the image samples with complicated backgrounds, such as continuous casting slabs and hot rolled steel plates, the defect identification rate obtained by RNAMlet was 1% higher than other three methods. For the image samples with simple backgrounds, such as cold rolled steel strips, the computation time of RNAMlet was one-tenth of the other three MGA methods, while the defect identification rates obtained by RNAMlet were higher than the other three methods.

Heat and corrosion resistant cast CN-12 type stainless steel with improved high temperature strength and ductility

DOEpatents

Mazias, Philip J [Oak Ridge, TN; McGreevy, Tim [Morton, IL; Pollard, Michael James [East Peoria, IL; Siebenaler, Chad W [Peoria, IL; Swindeman, Robert W [Oak Ridge, TN

2007-08-14

A cast stainless steel alloy and articles formed therefrom containing about 0.5 wt. % to about 10 wt. % manganese, 0.02 wt. % to 0.50 wt. % N, and less than 0.15 wt. % sulfur provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. Alloys of the present invention also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon. Such solution strengthening enhances the high temperature precipitation-strengthening benefits of fine dispersions of NbC. Such solid solution effects also enhance the stability of the austenite matrix from resistance to excess sigma phase or chrome carbide formation at higher service temperatures. The presence of sulfides is substantially eliminated.

Spray Deposition: A Fundamental Study of Droplet Impingement, Spreading and Consolidation

DTIC Science & Technology

1989-12-01

low alloy (HSLA) steel. Preforms of HSLA-100, a low carbon bainitic, copper precipitation strengthened HSLA steel...manufacturing process. Specifically, HSLA-100, a copper precipitation strengthened high-strength, low - alloy steel was spray cast via the Osprey’ m process...by spray casting. Preforms of HSLA-100, a low carbon bainitic, copper precipitation strengthened steel, were spray cast under differing conditions

Fracture Analysis of Cast Steel Sling

NASA Astrophysics Data System (ADS)

Li, Xinghui

2018-02-01

The fracture reasons of ZG270-500 cast steel sling are analyzed through such means as macroscopic morphology analysis, chemical composition analysis, and microscopic metallography analysis. Results: coarse Widmanstatten structure and casting defects occurring in casting and subsequent heat treatment process reduce the strength, plasticity and toughness of the steel, which is the main reason of brittle fracture of the sling during work, and corresponding improvement suggestions are proposed herein.

Thermomechanical processing of microalloyed powder forged steels and a cast vanadium steel

NASA Astrophysics Data System (ADS)

Dogan, B.; Davies, T. J.

1985-09-01

The effects of controlled rolling on transformation behavior of two powder forged (P/F) microalloyed vanadium steels and a cast microalloyed vanadium steel were investigated. Rolling was carried out in the austenitic range below the recrystallization temperature. Equiaxed grain structures were produced in specimens subjected to different reductions and different cooling rates. The ferrite grain size decreased with increasing deformation and cooling rate. Ferrite nucleated on second phase particles, deformation bands, and on elongated prior austenite grain boundaries; consequently a high fractional ferrite refinement was achieved. Deformation raised the ferrite transformation start temperature while the time to transformation from the roll finish temperature decreased. Cooling rates in the cast steel were higher than in P/F steels for all four cooling media used, and the transformation start temperatures of cast steels were lower than that of P/F steel. Intragranular ferrite nucleation, which played a vital role in grain refinement, increased with cooling rate. Fully bainitic microstructures were formed at higher cooling rates in the cast steel. In the P/F steels inclusions and incompletely closed pores served as sites for ferrite nucleation, often forming a ‘secondary’ ferrite. The rolling schedule reduced the size of large pores and particle surface inclusions and removed interconnected porosity in the P/F steels.

Alloy Design and Development of Cast Cr-W-V Ferritic Steels for Improved High-Temperature Strength for Power Generation Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klueh, R L; Maziasz, P J; Vitek, J M

2006-09-23

Economic and environmental concerns demand that the power-generation industry seek increased efficiency for gas turbines. Higher efficiency requires higher operating temperatures, with the objective temperature for the hottest sections of new systems {approx} 593 C, and increasing to {approx} 650 C. Because of their good thermal properties, Cr-Mo-V cast ferritic steels are currently used for components such as rotors, casings, pipes, etc., but new steels are required for the new operating conditions. The Oak Ridge National Laboratory (ORNL) has developed new wrought Cr-W-V steels with 3-9% Cr, 2-3% W, 0.25% V (compositions are in wt.%), and minor amounts of additionalmore » elements. These steels have the strength and toughness required for turbine applications. Since cast alloys are expected to behave differently from wrought material, work was pursued to develop new cast steels based on the ORNL wrought compositions. Nine casting test blocks with 3, 9, and 11% Cr were obtained. Eight were Cr-W-V-Ta-type steels based on the ORNL wrought steels; the ninth was COST CB2, a 9Cr-Mo-Co-V-Nb cast steel, which was the most promising cast steel developed in a European alloy-development program. The COST CB2 was used as a control to which the new compositions were compared, and this also provided a comparison between Cr-W-V-Ta and Cr-Mo-V-Nb compositions. Heat treatment studies were carried out on the nine castings to determine normalizing-and-tempering treatments. Microstructures were characterized by both optical and transmission electron microscopy (TEM). Tensile, impact, and creep tests were conducted. Test results on the first nine cast steel compositions indicated that properties of the 9Cr-Mo-Co-V-Nb composition of COST CB2 were better than those of the 3Cr-, 9Cr-, and 11Cr-W-V-Ta steels. Analysis of the results of this first iteration using computational thermodynamics raised the question of the effectiveness in cast steels of the Cr-W-V-Ta combination versus the Cr-Mo-V-Nb combination in COST CB2. To explore this question, nine more casting test blocks, four 3Cr steels and five 11Cr steels were purchased, and microstructure and mechanical properties studies similar to those described above for the first iteration of test blocks were conducted. Experimental results from the second iteration indicated that 11 Cr steels with excellent properties are possible. The 11Cr-1.5Mo-V-Nb steels were superior to 11Cr-2W-V-Ta steels, and it appears the former class of steels can be developed to have tensile and creep properties exceeding those of COST CB2. The W-Nb combination in an 11Cr-2W-V-Nb steel had tensile and short-time creep properties at 650 C better than the 11Cr-1.5Mo-V-Nb steels, although long-time low-stress properties may not be as good because of Laves phase formation. Based on the results, the next step in the development of improved casting steels involves acquisition of 11Cr-1.5Mo-V-Nb-N-B-C and 11Cr-2W-V-Nb-N-B-C steels on which long-term creep-rupture tests (>10,000 h) be conducted. For better oxidation and corrosion resistance, development of 11Cr steels, as opposed to a 9Cr steels, such as COST CB2, are important for future turbine designs that envision operating temperatures of 650 C.« less

The Influence of Vanadium Microalloying on the Production of Thin Slab Casting and Direct Rolled Steel Strip

NASA Astrophysics Data System (ADS)

Li, Yu; Milbourn, David

Vanadium microalloying is highly effective in high strength strip steels produced by thin slab casting and direct rolled process. Because of the high solubility of V(C,N) in austenite, vanadium is likely to remain in solution during casting, equalisation and rolling. Vanadium microalloyed steels have better hot ductility and are less prone to transverse cracking than niobium containing steels. Despite a coarse as-cast austenite grain size before rolling, significant grain refinement can be achieved in vanadium microalloyed steels by repeated recrystallization during rolling, resulting in a fine uniform ferrite microstructure in final strip. Almost all vanadium present in microalloyed steels is available to precipitate in ferrite as very fine particles, contributing to precipitation strengthening. Vanadium microalloyed steels show less sensitivity to rolling process variables and exhibit excellent combination of strength and toughness.

Structure and mechanical properties of improved cast stainless steels for nuclear applications

NASA Astrophysics Data System (ADS)

Kenik, E. A.; Busby, J. T.; Gussev, M. N.; Maziasz, P. J.; Hoelzer, D. T.; Rowcliffe, A. F.; Vitek, J. M.

2017-01-01

Casting of stainless steels is a promising and cost saving way of directly producing large and complex structures, such a shield modules or divertors for the ITER. In the present work, a series of modified high-nitrogen cast stainless steels has been developed and characterized. The steels, based on the cast equivalent of the composition of 316 stainless steel, have increased N (0.14-0.36%) and Mn (2-5.1%) content; copper was added to one of the heats. Mechanical tests were conducted with non-irradiated and 0.7 dpa neutron irradiated specimens. It was established that alloying by nitrogen significantly improves the yield stress of non-irradiated steels and the deformation hardening rate. Manganese tended to decrease yield stress but increased radiation hardening. The role of copper on mechanical properties was negligibly small. Analysis of structure was conducted using SEM-EDS and the nature and compositions of the second phases and inclusions were analyzed in detail. No ferrite formation or significant precipitation were observed in the modified steels. It was shown that the modified steels, compared to reference material (commercial cast 316L steel), had better strength level, exhibit significantly reduced elemental inhomogeneity and only minor second phase formation.

Experimental and numerical modelling of the fluid flow in the continuous casting of steel

NASA Astrophysics Data System (ADS)

Timmel, K.; Miao, X.; Wondrak, T.; Stefani, F.; Lucas, D.; Eckert, S.; Gerbeth, G.

2013-03-01

This article gives an overview of recent research activities with respect to the mold flow in the continuous casting of steel in presence of DC magnetic fields. The magnetic fields appear to be an attractive tool for controlling the melt flow in a contactless way. Various kinds of magnetic systems are already in operation in industrial steel casting, but the actual impact on the melt flow has not been sufficiently verified by experimental studies. The rapid development of innovative diagnostic techniques in low-melting liquid metals over the last two decades enables new possibilities for systematic flow measurements in liquid metal model experiments. A new research program was initiated at HZDR comprising three experimental facilities providing a LIquid Metal Model for continuous CASTing of steel (LIMMCAST). The facilities operate in a temperature range from room temperature up to 400∘C using the low-melting alloys GaInSn and SnBi, respectively. The experimental program is focused on quantitative flow measurements in the mold, the submerged entry nozzle and the tundish. Local potential probes, Ultrasonic Doppler Velocimetry (UDV) and Contactless Inductive Flow Tomography (CIFT) are employed to measure the melt flow. The behavior of two-phase flows in case of argon injection is investigated by means of the Mutual Inductance Tomography (MIT) and X-ray radioscopy. The experimental results provide a substantial data basis for the validation of related numerical simulations. Numerical calculations were performed with the software package ANSYS-CFX with an implemented RANS-SST turbulence model. The non-isotropic nature of MHD turbulence was taken into account by specific modifications of the turbulence model. First results of the LIMMCAST program reveal important findings such as the peculiar, unexpected phenomenon that the application of a DC magnetic field may excite non-steady, non-isotropic large-scale flow oscillations in the mold. Another important result of our study is that electrical boundary conditions, namely the wall conductivity ratio, have a serious influence on the mold flow while it is exposed to an external magnetic field.

Energy Saving Melting and Revert Reduction (E-SMARRT): Precision Casting of Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Von L. Richards

2011-09-30

This project addresses improvements in metal casting processes by reducing scrap and reducing the cost of production, due to scrap reduction from investment casting and yield improvement offered by lost foam casting as compared to no-bake or green sand molding. The objectives for the investment casting portion of the subtask are to improve knowledge of fracture toughness of mold shells and the sources of strength limiting flaws and to understand the effects of wax reclamation procedures on wax properties. Applying 'clean steel' approaches to pouring technology and cleanliness in investment casting of steel are anticipated to improve incoming materials inspectionmore » procedures as they affect the microstructure and toughness of the shell. This project focused on two areas of study in the production of steel castings to reduce scrap and save energy: (1) Reducing the amount of shell cracking in investment cast steel production; (2) Investigate the potential of lost foam steel casting The basic findings regarding investment casting shell cracking were: (1) In the case of post pouring cracking, this could be related to phase changes in silica upon cooling and could be delayed by pouring arrangement strategies that maintained the shell surface at temperature for longer time. Employing this delay resulted in less adherent oxidation of castings since the casting was cooler at the time o fair exposure. (2) A model for heat transfer through water saturated shell materials under steam pressure was developed. (3) Initial modeling result of autoclave de-waxing indicated the higher pressure and temperature in the autoclave would impose a steeper temperature gradient on the wax pattern, causing some melt flow prior to bulk expansion and decreasing the stress on the green shell. Basic findings regarding lost foam casting of steel at atmospheric pressure: (1) EPS foam generally decomposes by the collapse mode in steel casting. (2) There is an accumulation of carbon pick-up at the end of the casting opposite the gate. (3) It is recommended that lost foam castings in steel be gated for a quiescent fill in an empty cavity mold to prevent foam occlusion defects from the collapse mode. The energy benefit is primarily in yield savings and lower casting weight per function due to elimination of draft and parting lines for the larger lost foam castings. For the smaller investment casting, scrap losses due to shell cracking will be reduced. Both of these effects will reduce the metal melted per good ton of castings. There will also be less machine stock required per casting which is a yield savings and a small additional energy savings in machining. Downstream savings will come from heavy truck and railroad applications. Application of these processes to heavy truck castings will lighten the heavy truck fleet by about ten pounds per truck. Using ten years to achieve full penetration of the truck fleet at linear rate this will result in a fuel savings of 131 trillion BTU over ten years.« less

Effects of Manganese Content on Solidification Structures, Thermal Properties, and Phase Transformation Characteristics in Fe-Mn-Al-C Steels

NASA Astrophysics Data System (ADS)

Yang, Jian; Wang, Yu-Nan; Ruan, Xiao-Ming; Wang, Rui-Zhi; Zhu, Kai; Fan, Zheng-Jie; Wang, Ying-Chun; Li, Cheng-Bin; Jiang, Xiao-Fang

2015-04-01

To assist developments of the continuous-casting technology of Fe-Mn-Al-C steels, the solidification structures and the thermal properties of Fe-Mn-Al-C steel ingots with different manganese contents have been investigated and the phase transformation characteristics have been revealed by FactSage (CRCT-ThermFact Inc., Montréal, Canada). The results show that the thermal conductivity of the 0Mn steel is the highest, whereas the thermal conductivity of the 8Mn steel is slightly higher than that of the 17Mn steel. Increasing the manganese content promotes a columnar solidification structure and coarse grains in steel. With the increase of manganese content, the mass fraction of austenite phase is increased. Finally, a single austenite phase is formed in the 17Mn steel. The mean thermal expansion coefficients of the steels are in the range from 1.3 × 10-5 to 2.3 × 10-5 K-1, and these values increase with the increase of manganese content. The ductility of the 17Mn steel and the 8Mn steel are higher than 40 pct in the temperature range from 873 K to 1473 K (600 °C to 1200 °C), and the cracking during the straightening operation should be avoided. However, the ductility of the 0Mn steel is lower than 40 pct at 973 K and 1123 K (700 °C and 850 °C), which indicates that the temperature of the straightening operation during the continuous-casting process should be above 1173 K (900 °C). Manganese has the effect of enlarging the austenite phase region and reducing the δ-ferrite phase region and α-ferrite phase region. At the 2.1 mass pct aluminum level, the precipitate temperature of AlN is high. Thus, the formed AlN is too coarse to deteriorate the hot ductility of steel.

Phase transformations in cast duplex stainless steels

NASA Astrophysics Data System (ADS)

Kim, Yoon-Jun

Duplex stainless steels (DSS) constitute both ferrite and austenite as a matrix. Such a microstructure confers a high corrosion resistance with favorable mechanical properties. However, intermetallic phases such as sigma (sigma) and chi (chi) can also form during casting or high-temperature processing and can degrade the properties of the DSS. This research was initiated to develop time-temperature-transformation (TTT) and continuous-cooling-transformation (CCT) diagrams of two types of cast duplex stainless steels, CD3MN (Fe-22Cr-5Ni-Mo-N) and CD3MWCuN (Fe-25Cr-7Ni-Mo-W-Cu-N), in order to understand the time and temperature ranges for intermetallic phase formation. The alloys were heat treated isothermally or under controlled cooling conditions and then characterized using conventional metallographic methods that included tint etching, and also using electron microscopy (SEM, TEM) and wavelength dispersive spectroscopy (WDS). The kinetics of intermetallic-phase (sigma + chi) formation were analyzed using the Johnson-Mehl-Avrami (JMA) equation in the case of isothermal transformations and a modified form of this equation in the case of continuous cooling transformations. The rate of intermetallic-phase formation was found to be much faster in CD3MWCuN than CD3MN due mainly to differences in the major alloying contents such as Cr, Ni and Mo. To examine in more detail the effects of these elements of the phase stabilities, a series of eight steel castings was designed with the Cr, Ni and Mo contents systematically varied with respect to the nominal composition of CD3MN. The effects of varying the contents of alloying additions on the formation of intermetallic phases were also studied computationally using the commercial thermodynamic software package, Thermo-Calc. In general, a was stabilized with increasing Cr addition and chi by increasing Mo addition. However, a delicate balance among Ni and other minor elements such as N and Si also exists. Phase equilibria in DSS can be affected by local composition fluctuations in the cast alloy. This may cause discrepancy between thermodynamic prediction and experimental observation.

Performance Steel Castings

DTIC Science & Technology

2012-09-30

Development of Sand Properties 103 Advanced Modeling Dataset.. 105 High Strength Low Alloy (HSLA) Steels 107 Steel Casting and Engineering Support...to achieve the performance goals required for new systems. The dramatic reduction in weight and increase in capability will require high performance...for improved weapon system reliability. SFSA developed innovative casting design and manufacturing processes for high performance parts. SFSA is

Sixty Years of Casting Research

NASA Astrophysics Data System (ADS)

Campbell, John

2015-11-01

The 60 years of solidification research since the publication of Chalmer's constitutional undercooling in 1953 has been a dramatic advance of understanding which has and continues to be an inspiration. In contrast, 60 years of casting research has seen mixed fortunes. One of its success stories relates to improvements in inoculation of gray irons, and another to the discovery of spheroidal graphite iron, although both of these can be classified as metallurgical rather than casting advances. It is suggested that true casting advances have dated from the author's lab in 1992 when a critical surface turbulence condition was defined for the first time. These last 20 years have seen the surface entrainment issues of castings developed to a sufficient sophistication to revolutionize the performance of light alloy and steel foundries. However, there is still a long way to go, with large sections of the steel and Ni-base casting industries still in denial that casting defects are important or even exist. The result has been that special ingots are still cast poorly, and shaped casting operations have suffered massive losses. For secondary melted and cast materials, electro-slag remelting has the potential to be much superior to expensive vacuum arc remelting, which has cost our aerospace and defense industries dearly over the years. This failure to address and upgrade our processing of liquid metals is a serious concern, since the principle entrainment defect, the bifilm, is seen as the principle initiator of cracks in metals; in general, bifilms are the Griffith cracks that initiate failures by cracking. A new generation of crack resistant metals and engineering structures can now be envisaged.

Strip casting with fluxing agent applied to casting roll

DOEpatents

Williams, R.S.; O`Malley, R.J.; Sussman, R.C.

1997-07-29

A strip caster for producing a continuous strip includes a tundish for containing a melt, a pair of horizontally disposed water cooled casting rolls and devices for electrostatically coating the outer peripheral chill surfaces of the casting rolls with a powder flux material. The casting rolls are juxtaposed relative to one another for forming a pouting basin for receiving the melt through a teeming tube thereby establishing a meniscus between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line to a sealing chamber. A preferred flux is boron oxide having a melting point of about 550 C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll. 3 figs.

Effects of heat treatment on mechanical properties of h13 steel

NASA Astrophysics Data System (ADS)

Guanghua, Yan; Xinmin, Huang; Yanqing, Wang; Xingguo, Qin; Ming, Yang; Zuoming, Chu; Kang, Jin

2010-12-01

Heat treatment on the mechanical properties of H13 hot working die steel for die casting is discussed. The H13 steel for die casting was treated by different temperatures of vacuum quenching, tempering, and secondary tempering to investigate its mechanical properties. Strength, plasticity, hardness, and impact toughness of the H13 hot working die steel for die casting were measured. Microstructure, grain size, and carbide particle size after heat treatment have a great impact on the mechanical properties of H13 hot working die steel for die casting. The microstructure of the H13 was analyzed by scanning electron microscopy (SEM) and by a metallographic microscope. It is found that H13 exhibits excellent mechanical properties after vacuum quenching at 1050°C and twice tempering at 600°C.

Experimental Study On Flexural Behaviour Of Beams Reinforced With GFRP Rebars

NASA Astrophysics Data System (ADS)

Naveen Kumar, G.; Sundaravadivelu, Karthik

2017-07-01

In saline, moisture and cold conditions corrosion of steel is inevitable and the lot of economy is used for rehabilitation works. Corrosion of steel is nothing but oxidation of iron in moisture conditions and this corrosion leads to the spalling of concrete which intern reduces the strength of the structure. To reduce this corrosion effects, new materials with resistance against corrosion have to be introduced. Many experiments are going on using Glass Fiber Reinforced Polymer (GFRP) as alternate material for steel due to its non-corrosive nature, weight of GFRP is nearly one third of steel and ultimate tensile strength is higher than steel. In this paper, six beams are casted in which three beams are casted with steel as main and shear reinforcement and another three beams are casted with GFRP as main reinforcement with steel as shear reinforcing material. All beams casted are of same dimensions with variation in reinforcement percentage. The size of the beams casted is of length 1200 mm, breadth 100 mm and depth 200 mm. The clear cover of 25 mm is provided on top and bottom of the beam. Beams are tested under two-point loading with constant aspect ratio (a/d) and comparing the flexural strength, load deflection curves and types of failures of beams reinforced with GFRP as main reinforcement and beams reinforced with conventional steel. The final experimental results are compared with numerical results. M30 grade concrete with Conplast as a superplasticizer is used for casting beams.

Determination for the Entrapment Criterion of Non-metallic Inclusions by the Solidification Front During Steel Centrifugal Continuous Casting

NASA Astrophysics Data System (ADS)

Wang, Qiangqiang; Zhang, Lifeng

2016-06-01

In the current study, the three-dimensional fluid flow, heat transfer, and solidification in steel centrifugal continuous casting strands were simulated. The volume of fluid model was used to solve the multiphase phenomena between the molten steel and the air. The entrapment and final distribution of inclusions in the solidified shell were studied with the discussion on the effect of rotation behavior of the caster system. Main results indicate that after applying the rotation of the shell, the fluid flow transformed from a recirculation flow to a rotation flow in the mold region and was driven to flow around in the casting direction. As the distance below the meniscus increased, the distribution of the tangential speed of the flow and the centrifugal force along one diameter of the strand became symmetrical gradually. The jet flow from the nozzle hardly impinged on the same location on the shell due to the rotation of the shell during solidification. Thus, the shell thickness on the same height was uniform around, and the thinning shell and a hot spot on the surface of shell were avoided. Both of the measurement and the calculation about the distribution of oxide inclusions along the radial direction indicated the number of inclusions at the side and the center was more than that at the quarter on the cross section of billet. With a larger diameter, inclusions tended to be entrapped toward the center area of the billet.

Help for the Steel Industry

NASA Technical Reports Server (NTRS)

1991-01-01

A collaboration between NASA Lewis Research Center (LRC) and Gladwin Engineering resulted in the adaptation of aerospace high temperature metal technology to the continuous casting of steel. The continuous process is more efficient because it takes less time and labor. A high temperature material, once used on the X-15 research plane, was applied to metal rollers by a LRC developed spraying technique. Lewis Research Center also supplied mold prototype of metal composites, reducing erosion and promoting thermal conductivity. Rollers that previously cracked due to thermal fatigue, lasted longer. Gladwin's sales have increased, and additional NASA-developed innovations are anticipated.

78 FR 77421 - Certain Oil Country Tubular Goods From India: Preliminary Affirmative Countervailing Duty...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-23

... tubing, of iron (other than cast iron) or steel (both carbon and alloy), whether seamless or welded... and tubing, of iron (other than cast iron) or steel (both carbon and alloy), whether seamless or..., United States Steel Corporation, Boomerang Tube, Energex Tube, a division of JMC Steel Group, Northwest...

Mission Critical STEM Partnership with the Air Force Office of Scientific Research

DTIC Science & Technology

2015-04-06

Dr. Valerie Lundy-Wagner, Senior Research Associate, Community College Research Center Teachers College, Columbia University 29...composites. We were comparing our experiments vs. structural steel . Our project consisted of a 4x4 in square caste. The caste was fabricated by bonding...aluminum and stainless steel . The caste experiments varied from 3, 5, and 7 stainless steel rods embedded in the piece. We tested for tensile strength

Designing High Performance Steel Castings Today: Proceedings of the Steel Founders Society of America, Technical and Operating Conference December 7-10, 2016Chicago, IL

DTIC Science & Technology

2016-12-10

will be 2 x failure (critical) depth. G. INSPECTION REQUIREMENTS Either the No- Bake sand or Investment process is selected based on which... Bake sand and the Investment Casting Handbook by the Investment Casting Institute has the tolerance values for investment castings. Typically there

Continuous Cooling Transformation in Cast Duplex Stainless Steels CD3MN and CD3MWCuN

NASA Astrophysics Data System (ADS)

Kim, Yoon-Jun; Chumbley, L. Scott; Gleeson, Brian

2008-04-01

The kinetics of brittle phase transformation in cast duplex stainless steels CD3MN and CD3MWCuN was investigated under continuous cooling conditions. Cooling rates slower than 5 °C/min. were obtained using a conventional tube furnace with a programable controller. In order to obtain controlled high cooling rates, a furnace equipped to grow crystals by means of the Bridgman method was used. Samples were soaked at 1100 °C for 30 min and cooled at different rates by changing the furnace position at various velocities. The velocity of the furnace movement was correlated to a continuous-cooling-temperature profile for the samples. Continuous-cooling-transformation (CCT) diagrams were constructed based on experimental observations through metallographic sample preparations and optical microscopy. These are compared to calculated diagrams derived from previously determined isothermal transformation diagrams. The theoretical calculations employed a modified Johnson-Mehl-Avrami (JMA) equation (or Avrami equation) under assumption of the additivity rule. Rockwell hardness tests were made to present the correlation between hardness change and the amount of brittle phases (determined by tint-etching to most likely be a combination of sigma + chi) after cooling.

Large Eddy Simulations of Electromagnetic Braking Effects on Argon Bubble Transport and Capture in a Steel Continuous Casting Mold

NASA Astrophysics Data System (ADS)

Jin, Kai; Vanka, Surya P.; Thomas, Brian G.

2018-02-01

In continuous casting of steel, argon gas is often injected to prevent clogging of the nozzle, but the bubbles affect the flow pattern, and may become entrapped to form defects in the final product. Further, an electromagnetic field is frequently applied to induce a braking effect on the flow field and modify the inclusion transport. In this study, a previously validated GPU-based in-house code CUFLOW is used to investigate the effect of electromagnetic braking on turbulent flow, bubble transport, and capture. Well-resolved large eddy simulations are combined with two-way coupled Lagrangian computations of the bubbles. The drag coefficient on the bubbles is modified to account for the effects of the magnetic field. The distribution of the argon bubbles, capture, and escape rates, are presented and compared with and without the magnetic field. The bubble capture patterns are also compared with results of a previous RANS model as well as with plant measurements.

Large Eddy Simulations of Electromagnetic Braking Effects on Argon Bubble Transport and Capture in a Steel Continuous Casting Mold

NASA Astrophysics Data System (ADS)

Jin, Kai; Vanka, Surya P.; Thomas, Brian G.

2018-06-01

In continuous casting of steel, argon gas is often injected to prevent clogging of the nozzle, but the bubbles affect the flow pattern, and may become entrapped to form defects in the final product. Further, an electromagnetic field is frequently applied to induce a braking effect on the flow field and modify the inclusion transport. In this study, a previously validated GPU-based in-house code CUFLOW is used to investigate the effect of electromagnetic braking on turbulent flow, bubble transport, and capture. Well-resolved large eddy simulations are combined with two-way coupled Lagrangian computations of the bubbles. The drag coefficient on the bubbles is modified to account for the effects of the magnetic field. The distribution of the argon bubbles, capture, and escape rates, are presented and compared with and without the magnetic field. The bubble capture patterns are also compared with results of a previous RANS model as well as with plant measurements.

The development of ultrahigh strength low alloy cast steels with increased toughness

NASA Astrophysics Data System (ADS)

Lynch, Paul C.

This work describes the initial work on the development of the next generation of ultrahigh strength low alloy (UHSLA) cast steels. These UHSLA cast steels have both ultrahigh strength levels and good impact toughness. The influence of heat treatment, secondary processing using hot isostatic processing (HIP), and chemical composition on the microstructure and properties of UHSLA cast steels have been evaluated. The extent of microsegregation reduction expected during the heat treatment of UHSLA cast steels has also been estimated by diffusion modeling. This new family of UHSLA cast steels is similar in composition and properties to UHSLA wrought steels. However, the heat treatment and secondary processing of the UHSLA cast steels is used to develop microstructures and properties typically developed through thermomechanical processing and heat treatment for wrought UHSLA steels. Two martensitic UHSLA steels, 4340+ (silicon modified 4340) and ES-1 were investigated for this study. For the 4340+ alloy, heat treatment variables evaluated include homogenization temperature and time, tempering temperature, and austempering temperature and time. For the ES-1 alloy, heat treatment variables evaluated include homogenization temperature and time, austenization temperature, cryogenic treatment, and tempering temperature. The effect of high temperature hot isostatic processing (HIP) on the 4340+ and ES- 1 alloys was also investigated. Tensile properties, charpy v-notch impact toughness (CVN), microstructures, and fractographs have all been characterized after heat treatment. The effects of HIP on microporosity reduction in the ES-1 alloy were also investigated. The experiments carried out on the investment cast 4340+ alloy have shown that increasing the homogenization temperature can increase CVN without changing the ultimate tensile strength (UTS) or yield strength (YS) of the cast material. By replacing the homogenization step in the conventional heat treatment process with a high temperature HIP treatment, both the CVN and ductility of the alloy was found to increase while maintaining comparable ultimate tensile strength (UTS) and yield strength (YS) levels as compared to the original homogenization treatment. Austempering the (IC) 4340+ material led to a significant increase in CVN and ductility at the expense of UTS and yield strength as the primarily martensitic microstructure was converted to a mixed martensitic-bainitic structure. An initial heat of induction melted, aluminum deoxidized investment cast ES-1 with 0.06 wt % of aluminum showed that the average -40°F and +72°F impact toughness, % elongation, and UTS and YS of the fully heat treated investment cast + HIP ES-1 material lagged significantly behind that of the vacuum degassed cast + HIP ES-1 ingot material. Even though the % elongation and impact toughness of the investment cast ES-1 material changed between heat treatment conditions, the average UTS and YS values remained relatively unchanged throughout the heat treatments for the investment cast study. Etched micrographs of the investment cast ES-1 material showed evidence of significant differences in microsegregation reduction between the samples homogenized at 2125°F for 4 hours and those not homogenized at 2125°F for 4 hours. SEM fracture surface work performed on the investment cast material clearly showed that the induction melted investment and aluminum killed cast material contained significant amounts of MnS and Al2O3 inclusions that were not discovered in the vacuum degassed cast ingot material. Lastly, the results of a third heat of induction melted, aluminum deoxidized investment cast ES-1 material possessing just 0.01wt% of aluminum showed that the decrease in aluminum content from the first experimental heat did not improve the mechanical properties of the investment cast material. (Abstract shortened by UMI.)

Castings, Steel, Homogenization of Steel Castings

DTIC Science & Technology

1942-12-05

concerninr.. the ef- fe~ct of homogenizing herat-- treAment u-non the ballistic prop- erties -%f cLast steel armo--iercinr nrro jectilt:s. .arden.YD- 1 t...of hLmogenizing- treAments upon the3 corrosi;.A -.f quenched- Lr(- t c,-.rnered. c-.st steel. Harich, Riffin, -ri Bolotsk-2 .. ade two-bec-d weldahtil

Strip casting with fluxing agent applied to casting roll

DOEpatents

Williams, Robert S.; O'Malley, Ronald J.; Sussman, Richard C.

1997-01-01

A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed through a supply line (28) to a sealing chamber (26). A preferred flux is boron oxide having a melting point of about 550.degree. C. The flux coating enhances wetting of the steel melt to the casting roll and dissolves any metal oxide formed on the roll.

Procedure for flaw detection in cast stainless steel

DOEpatents

Kupperman, David S.

1988-01-01

A method of ultrasonic flaw detection in cast stainless steel components incorporating the steps of determining the nature of the microstructure of the cast stainless steel at the site of the flaw detection measurements by ultrasonic elements independent of the component thickness at the site; choosing from a plurality of flaw detection techniques, one such technique appropriate to the nature of the microstructure as determined and detecting flaws by use of the chosen technique.

Relationship Between Solidification Microstructure and Hot Cracking Susceptibility for Continuous Casting of Low-Carbon and High-Strength Low-Alloyed Steels: A Phase-Field Study

NASA Astrophysics Data System (ADS)

Böttger, B.; Apel, M.; Santillana, B.; Eskin, D. G.

2013-08-01

Hot cracking is one of the major defects in continuous casting of steels, frequently limiting the productivity. To understand the factors leading to this defect, microstructure formation is simulated for a low-carbon and two high-strength low-alloyed steels. 2D simulation of the initial stage of solidification is performed in a moving slice of the slab using proprietary multiphase-field software and taking into account all elements which are expected to have a relevant effect on the mechanical properties and structure formation during solidification. To account for the correct thermodynamic and kinetic properties of the multicomponent alloy grades, the simulation software is online coupled to commercial thermodynamic and mobility databases. A moving-frame boundary condition allows traveling through the entire solidification history starting from the slab surface, and tracking the morphology changes during growth of the shell. From the simulation results, significant microstructure differences between the steel grades are quantitatively evaluated and correlated with their hot cracking behavior according to the Rappaz-Drezet-Gremaud (RDG) hot cracking criterion. The possible role of the microalloying elements in hot cracking, in particular of traces of Ti, is analyzed. With the assumption that TiN precipitates trigger coalescence of the primary dendrites, quantitative evaluation of the critical strain rates leads to a full agreement with the observed hot cracking behavior.

(60)Co in cast steel matrix: A European interlaboratory comparison for the characterisation of new activity standards for calibration of gamma-ray spectrometers in metallurgy.

PubMed

Tzika, Faidra; Burda, Oleksiy; Hult, Mikael; Arnold, Dirk; Marroyo, Belén Caro; Dryák, Pavel; Fazio, Aldo; Ferreux, Laurent; García-Toraño, Eduardo; Javornik, Andrej; Klemola, Seppo; Luca, Aurelian; Moser, Hannah; Nečemer, Marijan; Peyrés, Virginia; Reis, Mario; Silva, Lidia; Šolc, Jaroslav; Svec, Anton; Tyminski, Zbigniew; Vodenik, Branko; Wätjen, Uwe

2016-08-01

Two series of activity standards of (60)Co in cast steel matrix, developed for the calibration of gamma-ray spectrometry systems in the metallurgical sector, were characterised using a European interlaboratory comparison among twelve National Metrology Institutes and one international organisation. The first standard, consisting of 14 disc shaped samples, was cast from steel contaminated during production ("originally"), and the second, consisting of 15 similar discs, from artificially-contaminated ("spiked") steel. The reference activity concentrations of (60)Co in the cast steel standards were (1.077±0.019) Bqg(-1) on 1 January 2013 12h00 UT and (1.483±0.022) Bqg(-1) on 1 June 2013 12h00 UT, respectively. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Cast CF8C-Plus Stainless Steel for Turbocharger Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maziasz, P.J.; Shyam, A.; Evans, N.D.

2010-06-30

The purpose of this Cooperative Research and Development Agreement (CRADA) project is to provide the critical test data needed to qualify CF8C-Plus cast stainless steel for commercial production and use for turbocharger housings with upgraded performance and durability relative to standard commercial cast irons or stainless steels. The turbocharger technologies include, but are not limited to, heavy-duty highway diesel engines, and passenger vehicle diesel and gasoline engines. This CRADA provides additional critical high-temperature mechanical properties testing and data analysis needed to quality the new CF8C-Plus steels for turbocharger housing applications.

Numerical simulation of turbulent flow and heat transfer in the wedge-shaped liquid metal pool of a twin-roll caster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seyedein, S.H.; Hasan, H.

1997-03-01

Controlled flow and heat transfer are important for the quality of a strip in a twin-roll continuous casting process. A numerical study was carried out to investigate the two-dimensional turbulent flow and heat transfer in the liquid stainless-steel-filled wedge-shaped cavity formed by the two counterrotating rolls in a twin-roll continuous casting system. The turbulent characteristics of the flow were modeled using a low-Reynolds-number {kappa}-{epsilon} turbulence model due to Launder and Sharma. The arbitrary nature of the computational domain was accounted for through the use of a nonorthogonal boundary-fitted coordinate system on a staggered grid. A control-volume-based finite difference scheme wasmore » used to solve the transformed transport equations. This study is primarily focused on elucidating the inlet superheat dissipation in the melt pool with the rolls being maintained at a constant liquidus temperature of the steel. A parametric study was carried out to ascertain the effect of the inlet superheat, the casting speed, and the roll gap at the nip of the rotating rolls on the flow and heat transfer characteristics. The velocity fields show two counterrotating recirculation zones in the upstream region. The local Nusselt number on the roll surface shows significant variations. The contours of temperature and turbulent viscosity show the complex nature of the turbulent transport phenomena to be expected in a twin-roll casting process.« less

A gradiometric version of contactless inductive flow tomography: theory and first applications

PubMed Central

Wondrak, Thomas; Stefani, Frank

2016-01-01

The contactless inductive flow tomography (CIFT) is a measurement technique that allows reconstructing the flow of electrically conducting fluids by measuring the flow-induced perturbations of one or various applied magnetic fields and solving the underlying inverse problem. One of the most promising application fields of CIFT is the continuous casting of steel, for which the online monitoring of the flow in the mould would be highly desirable. In previous experiments at a small-scale model of continuous casting, CIFT has been applied to various industrially relevant problems, including the sudden changes of flow structures in case of argon injection and the influence of a magnetic stirrer at the submerged entry nozzle. The application of CIFT in the presence of electromagnetic brakes, which are widely used to stabilize the flow in the mould, has turned out to be more challenging due to the extreme dynamic range between the strong applied brake field and the weak flow-induced perturbations of the measuring field. In this paper, we present a gradiometric version of CIFT, relying on gradiometric field measurements, that is capable to overcome those problems and which seems, therefore, a promising candidate for applying CIFT in the steel casting industry. This article is part of the themed issue ‘Supersensing through industrial process tomography’. PMID:27185963

A Study of the Cold Resistance of Pipe Coiled Stock Produced at Foundry-Rolling Works. Part 2

NASA Astrophysics Data System (ADS)

Bagmet, O. A.; Naumenko, V. V.; Smetanin, K. S.

2018-03-01

Results of a study of coiled stock from low-carbon steels alloyed with manganese and silicon and different additives of niobium and titanium are presented. The coiled stock is produced at foundry-rolling works by the method of direct rolling of thin slabs right after their continuous casting. The microdeformation of the crystal lattice and the crystallographic texture are determined. The conditions of formation of the most favorable structure and texture in the steels are specified.

Mathematical Modeling on the Growth and Removal of Non-metallic Inclusions in the Molten Steel in a Two-Strand Continuous Casting Tundish

NASA Astrophysics Data System (ADS)

Ling, Haitao; Zhang, Lifeng; Li, Hong

2016-10-01

In the current study, mathematical models were developed to predict the transient concentration and size distribution of inclusions in a two-strand continuous casting tundish. The collision and growth of inclusions were considered. The contribution of turbulent collision and Stokes collision was evaluated. The removal of inclusions from the top surface was modeled by considering the properties of inclusions and the molten steel, such as the wettability, density, size, and interfacial tension. The effect of composition of inclusions on the collision of inclusions was included through the Hamaker constant. Meanwhile, the effect of the turbulent fluctuation velocity on the removal of inclusions at the top surface was also studied. Inclusions in steel samples were detected using automatic SEM Scanning so that the amount, morphology, size, and composition of inclusions were achieved. In the simulation, the size distribution of inclusions at the end steel refining was used as the initial size distribution of inclusions at tundish inlet. The equilibrium time when the collision and coalescence of inclusions reached the steady state was equal to 3.9 times of the mean residence time. When Stokes collision, turbulent collision, and removal by floating were included, the removal fraction of inclusions was 16.4 pct. Finally, the removal of solid and liquid inclusions, such as Al2O3, SiO2, and 12CaO·7Al2O3, at the interface between the molten steel and slag was studied. Compared with 12CaO·7Al2O3 inclusions, the silica and alumina inclusions were much easier to be removed from the molten steel and their removal fractions were 36.5 and 39.2 pct, respectively.

Optimization of Melt Treatment for Austenitic Steel Grain Refinement

NASA Astrophysics Data System (ADS)

Lekakh, Simon N.; Ge, Jun; Richards, Von; O'Malley, Ron; TerBush, Jessica R.

2017-02-01

Refinement of the as-cast grain structure of austenitic steels requires the presence of active solid nuclei during solidification. These nuclei can be formed in situ in the liquid alloy by promoting reactions between transition metals (Ti, Zr, Nb, and Hf) and metalloid elements (C, S, O, and N) dissolved in the melt. Using thermodynamic simulations, experiments were designed to evaluate the effectiveness of a predicted sequence of reactions targeted to form precipitates that could act as active nuclei for grain refinement in austenitic steel castings. Melt additions performed to promote the sequential precipitation of titanium nitride (TiN) onto previously formed spinel (Al2MgO4) inclusions in the melt resulted in a significant refinement of the as-cast grain structure in heavy section Cr-Ni-Mo stainless steel castings. A refined as-cast structure consisting of an inner fine-equiaxed grain structure and outer columnar dendrite zone structure of limited length was achieved in experimental castings. The sequential of precipitation of TiN onto Al2MgO4 was confirmed using automated SEM/EDX and TEM analyses.

Effect of Slag-Steel Reaction on the Initial Solidification of Molten Steel during Continuous Casting

NASA Astrophysics Data System (ADS)

Wang, Wanlin; Lou, Zhican; Zhang, Haihui

2018-03-01

With the mold simulator technique, the effect of slag-steel reaction on the initial shell solidification as well as the heat transfer and lubrication behavior of the infiltrated mold/shell slag film was studied in this article. The results showed that the Al2O3 content, the CaO/SiO2 ratio, and the viscosity of mold flux were increased with the progress of the slag-steel reaction during casting. The slag-steel reaction has two major effects on the initial shell solidification: one is increasing the mold heat flux and shell thickness by the decrease of slag film thickness. The other is the reduction of mold heat flux by the increase of crystal fraction in slag film. Mold flux with a lower basicity, viscosity, and crystallization temperature would result in a larger liquid slag consumption and the uneven infiltration of slag into the mold and shell gap that eventually leads to the irregular solidification of initial shell with a poor surface quality, such as slag entrapment and depressions as well as glaciation marks. Conversely, mold flux with a higher viscosity, basicity, and crystallization temperature would result in a smaller liquid slag consumption, which would cause the poor mold lubrication, the longitudinal shell surface defects, and drag marks.

Effect of Slag-Steel Reaction on the Initial Solidification of Molten Steel during Continuous Casting

NASA Astrophysics Data System (ADS)

Wang, Wanlin; Lou, Zhican; Zhang, Haihui

2018-06-01

With the mold simulator technique, the effect of slag-steel reaction on the initial shell solidification as well as the heat transfer and lubrication behavior of the infiltrated mold/shell slag film was studied in this article. The results showed that the Al2O3 content, the CaO/SiO2 ratio, and the viscosity of mold flux were increased with the progress of the slag-steel reaction during casting. The slag-steel reaction has two major effects on the initial shell solidification: one is increasing the mold heat flux and shell thickness by the decrease of slag film thickness. The other is the reduction of mold heat flux by the increase of crystal fraction in slag film. Mold flux with a lower basicity, viscosity, and crystallization temperature would result in a larger liquid slag consumption and the uneven infiltration of slag into the mold and shell gap that eventually leads to the irregular solidification of initial shell with a poor surface quality, such as slag entrapment and depressions as well as glaciation marks. Conversely, mold flux with a higher viscosity, basicity, and crystallization temperature would result in a smaller liquid slag consumption, which would cause the poor mold lubrication, the longitudinal shell surface defects, and drag marks.

An Informatics Based Approach to Reduce the Grain Size of Cast Hadfield Steel

NASA Astrophysics Data System (ADS)

Dey, Swati; Pathak, Shankha; Sheoran, Sumit; Kela, Damodar H.; Datta, Shubhabrata

2016-04-01

Materials Informatics concept using computational intelligence based approaches are employed to bring out the significant alloying additions to achieve grain refinement in cast Hadfield steel. Castings of Hadfield steels used for railway crossings, requires fine grained austenitic structure. Maintaining proper grain size of this component is very crucial in order to achieve the desired properties and service life. This work studies the important variables affecting the grain size of such steels which includes the compositional and processing variables. The computational findings and prior knowledge is used to design the alloy, which is subjected to a few trials to validate the findings.

Effect of Heat Treatment on the Impact Toughness of `High-Chromium Cast Iron - Low Alloy Steel' Bimetal Components

NASA Astrophysics Data System (ADS)

Özdemir, Z.

2017-03-01

A bimetallic `low-alloy steel - high-chromium cast iron' composite obtained by successive sand casting is studied and shown to have good cohesion on the interface and no casting defects. The hardness and the impact toughness of the bimetal increase simultaneously. The microstructure is more homogeneous after diffusion annealing at 1040°C, rapid cooling, and 3-h tempering at 270°C.

Structure and mechanical properties of improved cast stainless steels for nuclear applications

DOE PAGES

Kenik, Edward A.; Busby, Jeremy T.; Gussev, Maxim N.; ...

2016-10-27

Casting of stainless steels is a promising and cost saving way of directly producing large and complex structures, such a shield modules or divertors for the ITER. Here, a series of modified high-nitrogen cast steels has been developed and characterized. The steels, based on the cast equivalent of 316 composition, have increased N (0.14-0.36%) and Mn (2-5.1%) content; copper was added to one of the heats. Mechanical tests were conducted with non-irradiated and neutron irradiated specimens at 0.7 dpa. It was established that alloying by nitrogen significantly improves the yield stress of non-irradiated steels and the deformation hardening rate. Manganesemore » tended to decrease yield stress, but increased radiation hardening. Furthermore, the role of copper on mechanical properties was negligibly small. Analysis of structure was conducted using SEM-EDS and the nature and compositions of the second phases and inclusions were analyzed in detail. We show that the modified steels, compared to reference material, exhibit significantly reduced elemental inhomogeneity and second phase formation.« less

[Measurement of chemical agents in metallurgy field: electric steel plant].

PubMed

Cottica, D; Grignani, E; Ghitti, R; Festa, D; Apostoli, P

2012-01-01

The steel industry maintains its important position in the context of the Italian production involving thousands of workers. The iron and steel processes are divided into primary steel industry, production of intermediate minerals, and secondary steel, scrap from the production of semi-finished industrial and consumer sector (metal inserted into components and metal used for dissipative uses, primarily coatings) and industrial waste. The paper presents the results of environmental monitoring carried out in some electric steel plant for the measurement of airborne chemicals that characterize the occupational exposure of workers employed in particular area like electric oven, to treatment outside the furnace, continuous casting area. For the sampling of the pollutants were used both personal and in fixed positions samplers. The pollutants measured are those typical of steel processes inhalable dust, metals, respirable dust, crystalline silica, but also Polycyclic Aromatic Hydrocarbons (PAH), polychlorinated dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs).

Development of cast alumina-forming austenitic stainless steels

DOE PAGES

Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; ...

2016-09-06

Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt. % are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt. % Ni with good creep strength and the ability to form a protective alumina scale for use atmore » temperatures up to 800 C - 850 C in H 2O-, S-, and C- containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloy along with improved oxidation resistance typical of alumina-forming alloys. Lastly, challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.« less

Development of Cast Alumina-Forming Austenitic Stainless Steels

NASA Astrophysics Data System (ADS)

Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

2016-11-01

Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

Simulation of cracking cores when molding piston components

NASA Astrophysics Data System (ADS)

Petrenko, Alena; Soukup, Josef

2014-08-01

The article deals with pistons casting made from aluminum alloy. Pistons are casting at steel mold with steel core. The casting is provided by gravity casting machine. The each machine is equipped by two metal molds, which are preheated above temperature 160 °C before use. The steel core is also preheated by flame. The metal molds and cores are heated up within the casting process. The temperature of the metal mold raise up to 200 °C and temperature of core is higher. The surface of the core is treated by nitration. The mold and core are cooled down by water during casting process. The core is overheated and its top part is finally cracked despite its intensive water-cooling. The life time cycle of the core is decreased to approximately 5 to 15 thousands casting, which is only 15 % of life time cycle of core for production of other pistons. The article presents the temperature analysis of the core.

Effect of Ultrasonic Melt Treatment on Microstructure and Mechanical Properties of 35CrMo Steel Casting

NASA Astrophysics Data System (ADS)

Shi, Chen; Li, Fan; Liang, Gen; Mao, Daheng

2018-01-01

Effects of different power ultrasonic on microstructure and mechanical properties of 35CrMo steel casting were investigated using optical microscopy (OM), scanning electron microscopy (SEM) and hardness testing. A self-developed experiment apparatus was used for the propagation of ultrasonic vibration into the 35CrMo steel melt to carry out ultrasonic treatment. The experimental results showed that compared to the traditional casting, ultrasonic treatment can obviously change the solidification microstructure of 35CrMo steel, which is changed from coarse dendrites to fined dendrites or equiaxed grains. With the increase of ultrasonic power, equiaxed crystal is remarkably refined and its area is broadened. The micro porosity percentage of ingot casting decreases significantly and the porosity defects can be suppressed under ultrasonic treatment. The mechanical properties of 35CrMo steel ingot after heat treatment were enhanced by ultrasonic treatment: the maximum tensile strength is improved by 8.4% and the maximum elongation increased by 1.5 times.

Electrochemical Synthesis of Core-Shell-Structured NbC-Fe Composite Powder for Enforcement in Low-Carbon Steel.

PubMed

Li, Hongmei; Song, Qiushi; Xu, Qian; Chen, Ying; Xu, Liang; Man, Tiannan

2017-11-01

An NbC-Fe composite powder was synthesized from an Nb₂O₅/Fe/C mixture by electrochemical reduction and subsequent carbonization in molten CaCl₂-NaCl. The composite has a core-shell structure, in which NbC acts as the cores distributing in the Fe matrix. A strong bonding between NbC and Fe is benefit from the core-shell structure. The sintering and electrochemical reduction processes were investigated to probe the mechanism for the reactions. The results show that NbC particles about several nanometers were embraced by the Fe shell to form a composite about 100 nm in size. This featured structure can feasibly improve the wettability and sinterability of NbC as well as the uniform distribution of the carbide in the cast steel. By adding the composite into steel in the casting process, the grain size of the casted steel was markedly deceased from 1 mm to 500 μm on average, favoring the hardening of the casted steel.

Analytical ultrasonics for structural materials

NASA Technical Reports Server (NTRS)

Kupperman, D. S.

1986-01-01

The application of ultrasonic velocity and attenuation measurements to characterize the microstructure of structural materials is discussed. Velocity measurements in cast stainless steel are correlated with microstructural variations ranging from equiaxed (elastically isotropic) to columnar (elastically anisotropic) grain structure. The effect of the anisotropic grain structure on the deviation of ultrasonic waves in cast stainless steel is also reported. Field-implementable techniques for distinguishing equiaxed from columnar grain structures in cast strainless steel structural members are presented. The application of ultrasonic velocity measurements to characterize structural ceramics in the green state is also discussed.

Statistical research using the multiple regression analysis in areas of the cast hipereutectoid steel rolls manufacturing

NASA Astrophysics Data System (ADS)

Kiss, I.; Alexa, V.; Serban, S.; Rackov, M.; Čavić, M.

2018-01-01

The cast hipereutectoid steel (usually named Adamite) is a roll manufacturing destined material, having mechanical, chemical properties and Carbon [C] content of which stands between steelandiron, along-withitsalloyelements such as Nickel [Ni], Chrome [Cr], Molybdenum [Mo] and/or other alloy elements. Adamite Rolls are basically alloy steel rolls (a kind of high carbon steel) having hardness ranging from 40 to 55 degrees Shore C, with Carbon [C] percentage ranging from 1.35% until to 2% (usually between 1.2˜2.3%), the extra Carbon [C] and the special alloying element giving an extra wear resistance and strength. First of all the Adamite roll’s prominent feature is the small variation in hardness of the working surface, and has a good abrasion resistance and bite performance. This paper reviews key aspects of roll material properties and presents an analysis of the influences of chemical composition upon the mechanical properties (hardness) of the cast hipereutectoid steel rolls (Adamite). Using the multiple regression analysis (the double and triple regression equations), some mathematical correlations between the cast hipereutectoid steel rolls’ chemical composition and the obtained hardness are presented. In this work several results and evidence obtained by actual experiments are presented. Thus, several variation boundaries for the chemical composition of cast hipereutectoid steel rolls, in view the obtaining the proper values of the hardness, are revealed. For the multiple regression equations, correlation coefficients and graphical representations the software Matlab was used.

Modeling and Measurements of Multiphase Flow and Bubble Entrapment in Steel Continuous Casting

NASA Astrophysics Data System (ADS)

Jin, Kai; Thomas, Brian G.; Ruan, Xiaoming

2016-02-01

In steel continuous casting, argon gas is usually injected to prevent clogging, but the bubbles also affect the flow pattern, and may become entrapped to form defects in the final product. To investigate this behavior, plant measurements were conducted, and a computational model was applied to simulate turbulent flow of the molten steel and the transport and capture of argon gas bubbles into the solidifying shell in a continuous slab caster. First, the flow field was solved with an Eulerian k- ɛ model of the steel, which was two-way coupled with a Lagrangian model of the large bubbles using a discrete random walk method to simulate their turbulent dispersion. The flow predicted on the top surface agreed well with nailboard measurements and indicated strong cross flow caused by biased flow of Ar gas due to the slide-gate orientation. Then, the trajectories and capture of over two million bubbles (25 μm to 5 mm diameter range) were simulated using two different capture criteria (simple and advanced). Results with the advanced capture criterion agreed well with measurements of the number, locations, and sizes of captured bubbles, especially for larger bubbles. The relative capture fraction of 0.3 pct was close to the measured 0.4 pct for 1 mm bubbles and occurred mainly near the top surface. About 85 pct of smaller bubbles were captured, mostly deeper down in the caster. Due to the biased flow, more bubbles were captured on the inner radius, especially near the nozzle. On the outer radius, more bubbles were captured near to narrow face. The model presented here is an efficient tool to study the capture of bubbles and inclusion particles in solidification processes.

Phosphorus Segregation in Meta-Rapidly Solidified Carbon Steels

NASA Astrophysics Data System (ADS)

Li, Na; Qiao, Jun; Zhang, Junwei; Sha, Minghong; Li, Shengli

2017-09-01

Twin-roll strip casters for near-net-shape manufacture of steels have received increased attention in the steel industry. Although negative segregation of phosphorus occurred in twin-roll strip casting (TRSC) steels in our prior work, its mechanism is still unclear. In this work, V-shaped molds were designed and used to simulate a meta-rapid solidification process without roll separating force during twin roll casting of carbon steels. Experimental results show that no obvious phosphorus segregation exist in the V-shaped mold casting (VMC) steels. By comparing TRSC and the VMC, it is proposed that the negative phosphorus segregation during TRSC results from phosphorus redistribution driven by recirculating and vortex flow in the molten pool. Meanwhile, solute atoms near the advancing interface are overtaken and incorporated into the solid because of the high solidification speed. The high rolling force could promote the negative segregation of alloying elements in TRSC.

Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility

DOEpatents

Maziasz, Philip J.; McGreevy, Tim; Pollard, Michael James; Siebenaler, Chad W.; Swindeman, Robert W.

2006-12-26

A CF8C type stainless steel alloy and articles formed therefrom containing about 18.0 weight percent to about 22.0 weight percent chromium and 11.0 weight percent to about 14.0 weight percent nickel; from about 0.05 weight percent to about 0.15 weight percent carbon; from about 2.0 weight percent to about 10.0 weight percent manganese; and from about 0.3 weight percent to about 1.5 weight percent niobium. The present alloys further include less than 0.15 weight percent sulfur which provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. The disclosed alloys also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon.

Heat and corrosion resistant cast CF8C stainless steel with improved high temperature strength and ductility

DOEpatents

Maziasz, Philip J.; McGreevy, Tim; Pollard, Michael James; Siebenaler, Chad W.; Swindeman, Robert W.

2010-08-17

A CF8C type stainless steel alloy and articles formed therefrom containing about 18.0 weight percent to about 22.0 weight percent chromium and 11.0 weight percent to about 14.0 weight percent nickel; from about 0.05 weight percent to about 0.15 weight percent carbon; from about 2.0 weight percent to about 10.0 weight percent manganese; and from about 0.3 weight percent to about 1.5 weight percent niobium. The present alloys further include less than 0.15 weight percent sulfur which provides high temperature strength both in the matrix and at the grain boundaries without reducing ductility due to cracking along boundaries with continuous or nearly-continuous carbides. The disclosed alloys also have increased nitrogen solubility thereby enhancing strength at all temperatures because nitride precipitates or nitrogen porosity during casting are not observed. The solubility of nitrogen is dramatically enhanced by the presence of manganese, which also retains or improves the solubility of carbon thereby providing additional solid solution strengthening due to the presence of manganese and nitrogen, and combined carbon.

The development of high strength corrosion resistant precipitation hardening cast steels

NASA Astrophysics Data System (ADS)

Abrahams, Rachel A.

Precipitation Hardened Cast Stainless Steels (PHCSS) are a corrosion resistant class of materials which derive their properties from secondary aging after a normalizing heat treatment step. While PHCSS materials are available in austenitic and semi-austenitic forms, the martensitic PHCSS are most widely used due to a combination of high strength, good toughness, and corrosion resistance. If higher strength levels can be achieved in these alloys, these materials can be used as a lower-cost alternative to titanium for high specific strength applications where corrosion resistance is a factor. Although wrought precipitation hardened materials have been in use and specified for more than half a century, the specification and use of PHCSS has only been recent. The effects of composition and processing on performance have received little attention in the cast steel literature. The work presented in these investigations is concerned with the experimental study and modeling of microstructural development in cast martensitic precipitation hardened steels at high strength levels. Particular attention is focused on improving the performance of the high strength CB7Cu alloy by control of detrimental secondary phases, notably delta ferrite and retained austenite, which is detrimental to strength, but potentially beneficial in terms of fracture and impact toughness. The relationship between age processing and mechanical properties is also investigated, and a new age hardening model based on simultaneous precipitation hardening and tempering has been modified for use with these steels. Because the CB7Cu system has limited strength even with improved processing, a higher strength prototype Fe-Ni-Cr-Mo-Ti system has been designed and adapted for use in casting. This prototype is expected to develop high strengths matching or exceed that of cast Ti-6Al-4V alloys. Traditional multicomponent constitution phase diagrams widely used for phase estimation in conventional stainless steels, give poor estimates of secondary phases in PHCSS. No measureable retained austenite was observed in any of the CB7Cu-1 steels studied, in spite of the fact that austenite is predicted by the constitution diagrams. A designed experiment using computationally derived phase equilibrium diagrams and actual experimental tests on CB7Cu of different compositions suggests that the ferrite phase is less stable than the constitution diagrams for austenitic stainless steels suggest. Delta ferrite was also more stable in slower-cooled sand cast material as compared to thin, fast-cooled investment cast material. High temperature solutionizing treatments were effective in dissolving delta ferrite at temperatures above 1900°F (˜1040°C). Delta ferrite dissolution was found to proceed at high rates during initial dissolution, and then was found to slow after 1 hour. Diffusion during the later stages is well-predicted by classical diffusion models. Repeated solution treatments were found to modestly increase both ductility and strength, likely due to subgrain refinement through austenite regrowth. Multistaged aging provided superior strength and toughness increases over similarly peak-aged and near peak-aged material aged at a single temperature. Peak-aged material fractography suggested that low energy quasi-cleavage fracture was likely due to age precipitate embrittlement along with some nucleation of MnS particulates at prior austenite grain boundaries. Yield strengths approaching 190 ksi (1310MPa) can be achieved in CB7Cu-1 if appropriate best-practices "+" processing techniques are used. This includes hot isostatic processing to reduce solidification segregation and heal microporosity, high temperature homogenization for effective age hardening and ferrite reduction, double-cycle solutionizing for structure refinement, and multistaged age strengthening for finer precipitate control. The experimental prototype 11-11PH (Fe-Ni-Cr-Ti-Mo) casting alloys was cast and was found to be delta-ferrite free in the as-cast condition. In this material, proper quench processing to eliminate excessive retained austenite was found to be most influential in terms of high strengths. It was also found that cooling below 0°C provided the best combination of strength and toughness, with the specific strength of the material exceeding that of cast Ti-6Al-4V material. Fractography studies suggest that titanium carbonitride and titanium carbon-nitride-sulfide inclusions limit the toughness of cast materials due to long exposures to ideal growth conditions during initial cooling. OIM studies also suggest that the retained austenite in properly processed 11-11PH alloy takes on an interlath structure, which likely contributes to toughness of the alloy, even at high-strength, peak aged conditions. Yield strengths approaching 235 ksi (1620 MPa) were achieved during initial heat treatment trials. It is expected that further improvements in properties can be achieved with continued improvement of processing for this new cast alloy system.

The Effect of Rare-Earth Metals on Cast Steels

DTIC Science & Technology

1954-04-01

as the 1-inch section is also illustrated in Figure 23 and consists of tempered bainite and tempered martensite. Both of the control steels (AE-1...section Tempered bainite and tempered martensite 4 inch section Figure 23 Microstructure ol the Mn-Cr-Mo base control steels . Etched with... bainite 4-inch Section Figure 25—Microstructures of the MnCr-Mo + Rare Earths f B cast steels . Etched with picral, SOOX - .1 €. Figure 26

Effect of Cooling Rate on Phase Transformations in a High-Strength Low-Alloy Steel Studied from the Liquid Phase

NASA Astrophysics Data System (ADS)

Dorin, Thomas; Stanford, Nicole; Taylor, Adam; Hodgson, Peter

2015-12-01

The phase transformation and precipitation in a high-strength low-alloy steel have been studied over a large range of cooling rates, and a continuous cooling transformation (CCT) diagram has been produced. These experiments are unique because the measurements were made from samples cooled directly from the melt, rather than in homogenized and re-heated billets. The purpose of this experimental design was to examine conditions pertinent to direct strip casting. At the highest cooling rates which simulate strip casting, the microstructure was fully bainitic with small regions of pearlite. At lower cooling rates, the fraction of polygonal ferrite increased and the pearlite regions became larger. The CCT diagram and the microstructural analysis showed that the precipitation of NbC is suppressed at high cooling rates, and is likely to be incomplete at intermediate cooling rates.

Growth of Legionella anisa in a model drinking water system to evaluate different shower outlets and the impact of cast iron rust.

PubMed

van der Lugt, Wilco; Euser, Sjoerd M; Bruin, Jacob P; Den Boer, Jeroen W; Walker, Jimmy T; Crespi, Sebastian

2017-11-01

Legionella continues to be a problem in water systems. This study investigated the influence of different shower mixer faucets, and the influence of the presence of cast iron rust from a drinking water system on the growth of Legionella. The research is conducted using a model of a household containing four drinking water systems. All four systems, which contained standard plumbing components including copper pipes and a water heater, were filled with unchlorinated drinking water. Furthermore, all systems had three different shower faucets: (A) a stainless-steel faucet, (B) a brass-ceramic faucet, and (C) a brass thermostatic faucet. System 1 was solely filled with drinking water. System 2 was filled with drinking water, and cast iron rust. System 3 was contaminated with Legionella, and system 4 was contaminated with a Legionella, and cast iron rust. During a period of 34 months, 450 cold water samples were taken from 15 sample points of the four drinking water systems, and tested for Legionella according to the Dutch Standard (NEN 6265). In system 4, with added cast iron rust, the stainless-steel mixer faucet (A) had the highest concentration of Legionella at >4.3log10CFU/l (>20,000CFU/l) and was positive in 46.4% of samples. In contrast, the stainless-steel mixer faucet (A) of system 3 without cast iron rust showed 14.3% positive samples with a maximum concentration of 3.9log10CFU/l (7600CFU/l) Legionella. Additionally, both contaminated systems (3 and 4), with the brass thermostatic faucet (C), tested positive for Legionella. System 3 in 85.7% of the samples, with a maximum concentration of 4.38log10CFU/l (24,200CFU/l), and system 4 in 64.3% of the samples with a maximum concentration of 4.13log10CFU/l (13.400CFU/l). These results suggest that both the type of faucet used in a drinking water system and the presence or absence of cast iron rust influence the growth of Legionella. Copyright © 2017 Elsevier GmbH. All rights reserved.

Infiltration of Slag Film into the Grooves on a Continuous Casting Mold

NASA Astrophysics Data System (ADS)

Cho, Jung-Wook; Jeong, Hee-Tae

2013-02-01

An analytical model is developed to clarify the slag film infiltration into grooves on a copper mold during the continuous casting of steel slabs. A grooved-type casting mold was applied to investigate the infiltration of slag film into the grooves of a pitch of 0.8 mm, width of 0.7 mm, and depth of 0.6 mm at the vicinity of a meniscus. The plant trial tests were carried out at a casting speed of 5.5 m min-1. The slag film captured at a commercial thin slab casting plant showed that both the overall and the liquid film thickness were decreased exponentially as the distance from the meniscus increases. In contrast, the infiltration of slag film into the grooves had been increased with increasing distance from the meniscus. A theoretic model has been derived based on the measured profile of slag film thickness to calculate the infiltration of slag film into the grooves. It successfully reproduces the empirical observation that infiltration ratio increased sharply along casting direction, about 80 pct at 50 mm and 95 pct at 150 mm below the meniscus. In the model calculation, the infiltration of slag film increases with increasing groove width and/or surface tension of the slag. The effect of groove depth is negligible when the width to depth ratio of the groove is larger than unity. It is expected that the developed model for slag film infiltration in this study will be widely utilized to optimize the design of groove dimensions in continuous casting molds.

Measurement and simulation of deformation and stresses in steel casting

NASA Astrophysics Data System (ADS)

Galles, D.; Monroe, C. A.; Beckermann, C.

2012-07-01

Experiments are conducted to measure displacements and forces during casting of a steel bar in a sand mold. In some experiments the bar is allowed to contract freely, while in others the bar is manually strained using embedded rods connected to a frame. Solidification and cooling of the experimental castings are simulated using a commercial code, and good agreement between measured and predicted temperatures is obtained. The deformations and stresses in the experiments are simulated using an elasto-viscoplastic finite-element model. The high temperature mechanical properties are estimated from data available in the literature. The mush is modeled using porous metal plasticity theory, where the coherency and coalescence solid fraction are taken into account. Good agreement is obtained between measured and predicted displacements and forces. The results shed considerable light on the modeling of stresses in steel casting and help in developing more accurate models for predicting hot tears and casting distortions.

Electrochemical Synthesis of Core–Shell-Structured NbC–Fe Composite Powder for Enforcement in Low-Carbon Steel

PubMed Central

Song, Qiushi; Xu, Qian; Chen, Ying; Xu, Liang; Man, Tiannan

2017-01-01

An NbC–Fe composite powder was synthesized from an Nb2O5/Fe/C mixture by electrochemical reduction and subsequent carbonization in molten CaCl2–NaCl. The composite has a core–shell structure, in which NbC acts as the cores distributing in the Fe matrix. A strong bonding between NbC and Fe is benefit from the core–shell structure. The sintering and electrochemical reduction processes were investigated to probe the mechanism for the reactions. The results show that NbC particles about several nanometers were embraced by the Fe shell to form a composite about 100 nm in size. This featured structure can feasibly improve the wettability and sinterability of NbC as well as the uniform distribution of the carbide in the cast steel. By adding the composite into steel in the casting process, the grain size of the casted steel was markedly deceased from 1 mm to 500 μm on average, favoring the hardening of the casted steel. PMID:29104266

Effect of carbon content on friction and wear of cast irons

NASA Technical Reports Server (NTRS)

Buckley, D. H.

1977-01-01

Friction and wear experiments were conducted with cast irons and wrought steels containing various amounts of carbon in the alloy structure in contact with 52100 steel. Gray cast irons were found to exhibit lower friction and wear characteristics than white cast irons. Further, gray cast iron wear was more sensitive to carbon content than was white. Wear with gray cast iron was linearly related to load, and friction was found to be sensitive to relative humidity and carbon content. The form, in which the carbon is present in the alloy, is more important, as the carbon content and no strong relationship seems to exist between hardness of these ferrous alloys and wear.

An Investigation of the Mold-Flux Performance for the Casting of Cr12MoV Steel Using a Mold Simulator Technique

NASA Astrophysics Data System (ADS)

Zhou, Lejun; Wang, Wanlin; Xu, Chao; Zhang, Chen

2017-08-01

Mold flux plays important roles in the process of continuous casting. In this article, the performance of mold flux for the casting of Cr12MoV steel was investigated by using a mold simulator. The results showed that the slag film formed in the gap between the initial shell and mold hot surface is thin and discontinuous during the casting process with the Flux BM, due to the absorption of chromic oxide inclusions into the liquid slag, while the slag film formed in the case of the optimized Flux NEW casting process is uniform. The main precipitated crystals in Flux BM slag film are cuspidine (Ca4Si2O7F2) and Cr3O4, but only Ca4Si2O7F2 precipitated in the Flux NEW case. Besides, both the responding temperature and heat flux in the case of Flux BM are relatively higher and fluctuate in a larger amplitude. The surface of the shell obtained in the case of the Flux BM experiment is quite uneven, and many severe depressions, cracks, and entrapped slags are observed in the surface due to the lack of lubrication. However, the obtained shell surface in the case of the Flux NEW shows good surface quality due to the addition of B2O3 and the adjustment of basicity, which can compensate for the negative effects of the mold-flux properties caused by the absorption of chromic oxide during the casting process.

Inclusion behaviour in the liquid core during continuous casting

NASA Astrophysics Data System (ADS)

Jiang, Guang S.

Water models using perspex have been built to study the fluid flow and recirculation patterns developed in the sump of a steel continuous casting machine and the influences these have on the behaviour of inclusions. An experimental method has been devised to simulate the behaviour of inclusions in the sump and to study the apportionment of the input flux of inclusions between the molten mould powder layer and the strand. The method entails the uses of finely dispersed coloured paraffin oil in the inlet stream together with a floating colourless paraffin layer on the top of the water in the model mould to simulate the molten powder layer on top of the molten steel.A theoretical model has been formulated which relates the inclusion separation in the sump to the fluid flow there. The inclusion removal ratio in the sump for a given continuous casting machine can be predicted using this theoretical model. The model, using the properties of liquid steel and practicable casting speeds, demonstrates that the removal of inclusions of small size (<40 um) from the mould sump is less than 5% efficient.Inclusion agglomeration plays an important role in inclusion removal. It has been shown that deep submersion of the SEN enhances the agglomeration of inclusion particle. Under certain conditions, for example, the average particle diameter in the meniscus region has been found to be as much as three times its value at the SEN nozzle.The use of fine alumina flakes or small air bubbles, together with a plane light source, has been found to be very successful in studying the fluid flow patterns developed in three-dimensional models. Employing this method, the fluid flow patterns developed on different planes within the model mould have been viewed and recorded photographically. The photographs so obtained have helped to explain the results obtained for the removal of inclusions. The fluid flow patterns developed when small outside diameter nozzles with deep SEN submerged depths are used have been found to be of benefit to the removal of inclusions.Increasing the SEN submerged depth promotes inclusion agglomeration and hence increases the inclusion removal ratio. Reducing the nozzle outside diameter and the casting speed increases the inclusion removal ratio in the sump. But the infleunces of these latter changes are not very strong, so that inclusion removal consideration need not influence the design strategies used for the casting speed and nozzle outside diameter. The SEN port angle has a little effect on the inclusion removal when using deep SEN submerged depth.Although argon stream introduced into the tundish nozzle stream can protect the nozzle blockage, it is not beneficial to the inclusion removal in the sump.

Hot tensile behaviour in silicon-killed boron microalloyed steels

NASA Astrophysics Data System (ADS)

Chown, Lesley H.; Cornish, Lesley A.

2017-10-01

Low carbon steel for drawing and cold heading applications should have low strength, high ductility and low strain ageing rates. To achieve this, nitrogen must be removed from solid solution, which can be done by low additions of boron. A wire producer had been experiencing occasional problems with severe cracking on silicon-killed, boron steel billets during continuous casting, but the solution was not obvious. Samples from four billets, each from different casts, were removed for analysis and testing. The tested steel compositions were within the specification limits, with boron to nitrogen ratios of 0.40-1.19. Hot ductility testing was performed on a Gleeble 1500 using parameters approximating the capabilities of this particular billet caster. The steel specimens were subjected to in situ melting, then cooled at a rate of 2 C.s-1 to temperatures in the range 750-1250°C, where they were then pulled to failure at a strain rate of 8x10-4 s-1. In this work, it was found that both the boron to nitrogen ratio and the manganese to sulphur ratio influenced the hot ductility and hence the crack susceptibility. Excellent hot ductility was found for B:N ratios above 1.0, which confirmed that the B:N ratio should be above a stoichiometric value of 0.8 to remove all nitrogen from solid solution. TEM analysis showed that coarse BN precipitates nucleated on other precipitates, such as (Fe,Mn)S, which have relatively low melting points, and are detrimental to hot ductility. Low Mn:S ratios of 10 - 12 were shown to promote precipitation of FeS, so a Mn:S > 14 was recommended. A narrower billet surface temperature range for straightening was recommended to prevent transverse surface cracking. Additionally, analysis of industrial casting data showed that the scrap percentage due to transverse cracking increased significantly for Mn:S < 14. An exponential decay relationship between the manganese to sulphur ratio and the average scrap percentage due to transverse cracking was derived as a simple tool to predict, and hence mitigate, scrap levels in the casting plant.

Development of fully dense and high performance powder metallurgy HSLA steel using HIP method

NASA Astrophysics Data System (ADS)

Liu, Wensheng; Pang, Xinkuan; Ma, Yunzhu; Cai, Qingshan; Zhu, Wentan; Liang, Chaoping

2018-05-01

In order to solve the problem that the mechanical properties of powder metallurgy (P/M) steels are much lower than those of traditional cast steels with the same composition due to their porosity, a high–strength–low–alloy (HSLA) steel with fully dense and excellent mechanical properties was fabricated through hot isostatic pressing (HIP) using gas–atomized powders. The granular structure in the P/M HIPed steel composed of bainitic ferrite and martensite–austenite (M–A) islands is obtained without the need of any rapid cooling. The P/M HIPed steel exhibit a combination of tensile strength and ductility that surpasses that of conventional cast steel and P/M sintered steel, confirming the feasibility of fabricating high performance P/M steel through appropriate microstructural control and manufacture process.

Light weight and high strength materials made of recycled steel and aluminum

NASA Astrophysics Data System (ADS)

Nounezi, Thomas

Recycling has proven not only to address today's economical, environmental and social issues, but also to be imperative for the sustainability of human technology. The current thesis has investigated the feasibility of a new philosophy for Recycling (Alloying-Recycling) using steel 1020 and aluminum 6061T6. The study was limited to the metallurgical aspects only and has highlighted the potential of recycled alloys made of recycled aluminum and steel to exhibit substantially increased wear resistance and strength-to-weight ratio as compared to initial primary materials. Three alloy-mixtures are considered: TN3 (5wt% 1020 +95wt% 6061T6); TN5 (0.7wt% 1020 + 99.3wt% 6061T6); and TN4 (10wt% 6061T6 + 90wt% 1020). A Tucker induction power supply system (3kW; 135-400 kHz) is used to melt the alloy mixtures for casting in graphite crucibles. Heat treatment of the cast samples is done using a radiation box furnace. Microscopy, Vickers hardness and pin-on-disc abrasive wear tests are performed. Casting destroyed the initial microstructures of the alloys leading to a hardness reduction in the as-cast and solution heat-treated aluminum rich samples to 60 Hv from 140 Hv. Ageing slightly increased the hardness of the cast samples and provided a wear resistance two times higher than that of the initial 6061T6 material. On the steel rich side, the hardness of the as-cast TN4 was 480 Hv, which is more than twice as high as the initial hardness of steel 1020 of 202 Hv; this hints to strong internal and residual stress, probably martensite formation during fast cooling following casting. Solution heat treatment lowered the hardness to the original value of steel 1020, but provided about ten (10) times higher wear resistance; this suggests higher ductility and toughness of normalised TN4 as compared to 1020. In addition, TN4 exhibits about 25% weight reduction as compared to 1020. The actual recycling process and the effect of non-metallic impurities shall be investigated in future works. Also, the casting and heat treatment processes need to be improved.

Microstructure and Mechanical Properties of a Low Alloyed MnB Cast Steel

NASA Astrophysics Data System (ADS)

Luo, Kaishuang; Bai, Bingzhe

2010-08-01

The microstructure and mechanical properties of a low alloyed MnB cast steel designed for coupler castings of trucks were studied. The results show that the microstructure of the MnB cast steel after water quenching is lath martensite and a small amount of massive islands in the matrix of lath martensite. The average size of the martensite packets is about 10 μm in length. Carbides precipitated dispersively at the tempering temperature of 450 °C. The carbides are slender and fibrous, of which the microstructure was θ-phase (Fe, Mn)3C characterized by TEM. The MnB cast steel has good hardenability and tempering stability. Excellent combination of strength, ductility and low-temperature toughness were obtained after water-quenching and 450 °C tempering: Rm = 960-1040 MPa, ReL = 880-900 MPa, A = 19-21%, Z = 56-58%. Especially, the impact energy of the Charpy V-Notch (CVN) specimens reached 70-88 J at -40 °C. The fracture mechanism is transcrystalline fracture both for ambient temperature uniaxial tensile test specimens and for CVN impact test specimens broken at -40 °C, where the whole surfaces were manifested as voids and dimples.

A Review of Permanent Magnet Stirring During Metal Solidification

NASA Astrophysics Data System (ADS)

Zeng, Jie; Chen, Weiqing; Yang, Yindong; Mclean, Alexander

2017-12-01

Rather than using conventional electromagnetic stirring (EMS) with three-phase alternating current, permanent magnet stirring (PMS), based on the use of sintered NdFeB material which has excellent magnetic characteristics, can be employed to generate a magnetic field for the stirring of liquid metal during solidification. Recent experience with steel casting indicates that PMS requires less than 20 pct of the total energy compared with EMS. Despite the excellent magnetic density properties and low power consumption, this relatively new technology has received comparatively little attention by the metal casting community. This paper reviews simulation modeling, experimental studies, and industrial trials of PMS conducted during recent years. With the development of magnetic simulation software, the magnetic field and associated flow patterns generated by PMS have been evaluated. Based on the results obtained from laboratory experiments, the effects of PMS on metal solidification structures and typical defects such as surface pinholes and center cavities are summarized. The significance of findings obtained from trials of PMS within the metals processing sector, including the continuous casting of steel, are discussed with the aim of providing an overview of the relevant parameters that are of importance for further development and industrial application of this innovative technology.

Causes of Cracking in Quenching of the Parts Made of Steels and Cast Iron and Recommendations for Their Removal: A Review

NASA Astrophysics Data System (ADS)

Kuznetsov, A. A.; Rudnev, V. I.

2017-12-01

The domestic and foreign experience on revealing the causes of quenching cracking and its prevention is generalized. We consider the works performed on the machine parts made of carbon and alloyed pearlitic steel and quenchable cast irons.

Assessing dust exposure in an integrated iron and steel manufacturing plant in South India.

PubMed

Ravichandran, B; Krishnamurthy, V; Ravibabu, K; Raghavan, S; Rajan, B K; Rajmohan, H R

2008-01-01

A study to monitor and estimate respirable particulate matter (RPM), toxic trace metal concentrations in the work environment was carried out in different sections of an integrated steel manufacturing industry. The average RPM concentration observed varied according to the section blast furnace was 2.41 mg/m;{3}; energy optimization furnace, 1.87 mg/m;{3}; sintering plant, 0.98 mg/m;{3}; continuous casting machine, 1.93 mg/m;{3}. The average trace metal concentration estimated from the RPM samples like iron, manganese, lead and chromium did not exceed ACGIH prescribed levels.

Mechanical properties of aluminium fused SiO2 particulate composites cast using metallic and non-metallic chills

NASA Astrophysics Data System (ADS)

Harshith, H. S.; Hemanth, Joel

2018-04-01

This research work aims at developing and mechanical characterization of aluminium (LM13) based metal matrix composite reinforced with varying percentage of fused SiO2 (3%,6%,9%,12%). The mechanical properties are completely dependent on the microstructural parameters of the system. Also the microstructure further depends on the cooling rates during solidification process. Various Chills like Silicon carbide, Mild steel, Copper were used during the casting process to increase the rate of solidification, which enhances the mechanical properties of the composite. The chill casted specimens were subjected to tensile and hardness tests followed by microstructure studies. A casting produced using mild steel chill exhibited higher young's modulus and was found to be maximum at 9% reinforcement. Finer microstructure and better UTS were seen for specimen's casted using copper chills, whereas silicon carbide and mild steel chills gave rise to very coarse structure with reduced UTS values compared to copper chills.

Shrinkage Prediction for the Investment Casting of Stainless Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabau, Adrian S

2007-01-01

In this study, the alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. Dimensions of the die tooling, wax pattern, and casting were measured using a Coordinate Measurement Machine in order to obtain the actual tooling allowances. The alloy dimensions were obtained from numerical simulation results of solidification, heat transfer, and deformation phenomena. The numerical simulation results for the shrinkage factors were compared with experimental results.

Structural Amorphous Steels

NASA Astrophysics Data System (ADS)

Lu, Z. P.; Liu, C. T.; Thompson, J. R.; Porter, W. D.

2004-06-01

Recent advancement in bulk metallic glasses, whose properties are usually superior to their crystalline counterparts, has stimulated great interest in fabricating bulk amorphous steels. While a great deal of effort has been devoted to this field, the fabrication of structural amorphous steels with large cross sections has remained an alchemist’s dream because of the limited glass-forming ability (GFA) of these materials. Here we report the discovery of structural amorphous steels that can be cast into glasses with large cross-section sizes using conventional drop-casting methods. These new steels showed interesting physical, magnetic, and mechanical properties, along with high thermal stability. The underlying mechanisms for the superior GFA of these materials are discussed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Zhiqi; He, Qing, E-mail: heqing@ise.neu.edu.cn; Xie, Zhi

For real-time and precise measurement of molten steel level in tundish during continuous casting, slag level and slag thickness are needed. Among which, the problem of slag thickness measurement has been solved in our previous work. In this paper, a systematic solution for slag level measurement based on laser triangulation is proposed. Being different from traditional laser triangulation, several aspects for measuring precision and robustness have been done. First, laser line is adopted for multi-position measurement to overcome the deficiency of single point laser range finder caused by the uneven surface of the slag. Second, the key parameters, such asmore » installing angle and minimum requirement of the laser power, are analyzed and determined based on the gray-body radiation theory to fulfill the rigorous requirement of measurement accuracy. Third, two kinds of severe noises in the acquired images, which are, respectively, caused by heat radiation and Electro-Magnetic Interference (EMI), are cleaned via morphological characteristic of the liquid slag and color difference between EMI and the laser signals, respectively. Fourth, as false target created by stationary slag usually disorders the measurement, valid signals of the slag are distinguished from the false ones to calculate the slag level. Then, molten steel level is obtained by the slag level minus the slag thickness. The measuring error of this solution is verified by the applications in steel plants, which is ±2.5 mm during steady casting and ±3.2 mm at the end of casting.« less

CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

CAST FLOOR WITH VIEW OF TORPEDO LADLE (BENEATH CAST FLOOR) AND KEEPERS OF THE CAST HOUSE FLOOR, S.L. KIMBROUGH AND DAVID HOLMES. - U.S. Steel, Fairfield Works, Blast Furnace No. 8, North of Valley Road, West of Ensley-Pleasant Grove Road, Fairfield, Jefferson County, AL

46 CFR 160.032-3 - Construction of davits.

Code of Federal Regulations, 2010 CFR

2010-10-01

...-hearth or electric furnace process shall be in accordance with ASTM A 36/A 36 M (incorporated by reference, see § 160.032-1). (2) Steel castings not intended for fusion welding shall be in accordance with... 70-36. (3) Steel castings intended to be fabricated by fusion welding shall be in accordance with...

46 CFR 160.032-5 - Inspection and testing of davits.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Inspection and testing of davits. (a) Material testing. (1) Where davit arms and frames are fabricated of steel castings, an inspector shall be present at the foundry where such castings are made to witness the... affidavit stating that the structural steel complies with the requirements of the specification noted in...

46 CFR 160.032-5 - Inspection and testing of davits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Inspection and testing of davits. (a) Material testing. (1) Where davit arms and frames are fabricated of steel castings, an inspector shall be present at the foundry where such castings are made to witness the... affidavit stating that the structural steel complies with the requirements of the specification noted in...

Energy Saving Melting and Revert Reduction Technology (Energy-SMARRT): Clean Steel Casting Production

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuyucak, Selcuk; Li, Delin

2013-12-31

Inclusions in steel castings can cause rework, scrap, poor machining, and reduced casting performance, which can obviously result in excess energy consumption. Significant progress in understanding inclusion source, formation and control has been made. Inclusions can be defined as non-metallic materials such as refractory, sand, slag, or coatings, embedded in a metallic matrix. This research project has focused on the mold filling aspects to examine the effects of pouring methods and gating designs on the steel casting cleanliness through water modeling, computer modeling, and melting/casting experiments. Early in the research project, comprehensive studies of bottom-pouring water modeling and low-alloy steelmore » casting experiments were completed. The extent of air entrainment in bottom-poured large castings was demonstrated by water modeling. Current gating systems are designed to prevent air aspiration. However, air entrainment is equally harmful and no prevention measures are in current practice. In this study, new basin designs included a basin dam, submerged nozzle, and nozzle extension. The entrained air and inclusions from the gating system were significantly reduced using the new basin method. Near the end of the project, there has been close collaboration with Wescast Industries Inc., a company manufacturing automotive exhaust components. Both computer modeling using Magma software and melting/casting experiments on thin wall turbo-housing stainless steel castings were completed in this short period of time. Six gating designs were created, including the current gating on the pattern, non-pressurized, partially pressurized, naturally pressurized, naturally pressurized without filter, and radial choke gating without filter, for Magma modeling. The melt filling velocity and temperature were determined from the modeling. Based on the simulation results, three gating designs were chosen for further melting and casting experiments on the same casting pattern using the lip pouring method. It was observed again that gating designs greatly influenced the melt filling velocity and the number of inclusion defects. The radial choked gating showed improvements in casting cleanliness and yield over the other gatings, even though no mold filters were used in the gating system.« less

Effect of Porosity on Deformation, Damage, and Fracture of Cast Steel

NASA Astrophysics Data System (ADS)

Hardin, R. A.; Beckermann, C.

2013-12-01

A combined experimental and computational study is performed to investigate the effect of centerline shrinkage porosity on deformation, damage, and fracture of cast steel under tensile testing. Steel plates containing shrinkage porosity are cast in sand molds, machined into test coupons, and tensile tested to fracture. The average volumetric porosity in the gage section of the specimens with porosity ranges from 0.10 to 0.27 pct. Ductility in the test castings with porosity is markedly reduced with the percent elongation data ranging from 12.8 to 19.6 pct; vs 22 pct elongation for the sound material. Radiographic imaging is used to measure and reconstruct the porosity field in the test specimens. The reconstructed porosity field is then used in a finite-element stress analysis simulating the tensile testing. Local elastic properties are reduced according to the porosity fraction present. Porous metal plasticity theory is used to model the damage due to porosity and the fracture. Good agreement is obtained between the measured and predicted stress-strain curves and fracture behaviors. The reduction in ductility is predicted well by comparing the measured and the simulated elongations. The computational modeling approach used in this study allows for a detailed evaluation of the effect of porosity, including its size, shape, and location, on the fracture behavior of steel castings.

Tempering Behavior of TiC-Reinforced SKD11 Steel Matrix Composite

NASA Astrophysics Data System (ADS)

Hwang, Ji-In; Kim, Seong Hoon; Heo, Yoon-Uk; Kim, Dae Ha; Hwang, Keum-Cheol; Suh, Dong-Woo

2018-05-01

TiC-reinforced SKD11 steel matrix composite, fabricated by a pressure infiltration casting, undergoes monotonic decrease in hardness as tempering temperature increases. Element mappings by TEM-EDS and thermodynamic calculation indicate that remarkable redistribution of V between the reinforcement and the steel matrix occurs by partial dissolution and re-precipitation of MC carbides upon casting process. The absence of secondary hardening is led by the enrichment of V in the reinforcement that reduces the V content in the steel matrix; this reduction in V content makes the precipitation of fine VC sluggish during the tempering.

Metallurgical Examination of a Cast Turret Manufactured by the American Steel Foundries

DTIC Science & Technology

1945-03-28

ferrite and a structure stmlar to tempered bainite tnd fine carb ides. 4. The results of this investigatio l inCicate that the American Steel Foundries...1hirrot No 11Mufac t~redj~ t!Le American~ Steel Poidcries J.J Wil jr;I 4?1 ’JJ No. B171; 11000 Picral Structure simuilar to temnpered bainite Lavsociated wita fine carbides and ferrite patcha.. FIGM I ...examination has been conducted on two samples of the. cast turret to. 3171 for the Hedium Tank II4, maiufactured by the i.meriaan Steel Foundries, which

Tempering Behavior of TiC-Reinforced SKD11 Steel Matrix Composite

NASA Astrophysics Data System (ADS)

Hwang, Ji-In; Kim, Seong Hoon; Heo, Yoon-Uk; Kim, Dae Ha; Hwang, Keum-Cheol; Suh, Dong-Woo

2018-03-01

TiC-reinforced SKD11 steel matrix composite, fabricated by a pressure infiltration casting, undergoes monotonic decrease in hardness as tempering temperature increases. Element mappings by TEM-EDS and thermodynamic calculation indicate that remarkable redistribution of V between the reinforcement and the steel matrix occurs by partial dissolution and re-precipitation of MC carbides upon casting process. The absence of secondary hardening is led by the enrichment of V in the reinforcement that reduces the V content in the steel matrix; this reduction in V content makes the precipitation of fine VC sluggish during the tempering.

Vacuum investment cast PH13-8Mo corrosion resistant steel. (SAE standard)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1991-07-01

An industry-wide interest has arisen with regards to the properties and capabilities of investment cast PH 13-8Mo corrosion resistant steel. Specifically of interest are the structural applications in the aerospace industry for this product heat treated to the H1000 condition. The objective of this AMEC cooperative test program was to generate and compile useful data for aerospace structural evaluation of investment cast PH 13-8Mo heat treated to H1000. The determination was made of overall mechanical properties, fatigue, fracture toughness, and crack growth data along with basic microstructural evaluation of the investment cast material. The evaluation of mechanical property variations betweenmore » cast and machined tensile specimens and evaluation of microstructural constituents. PH 13-8Mo, H1000 investment castings for use in the aerospace industry is included.« less

Influence of volume ratio of liquid to solid and low pouring temperature on interface structure of cast Babbitt-steel bimetal composite

NASA Astrophysics Data System (ADS)

Fathy, Naglaa; Ramadan, Mohamed

2018-05-01

The influence of volume ratio of liquid to Solid and low pouring temperature on interface structure of cast Babbitt-steel bimetal composite was evaluated for static casting technique. At low pouring temperature of 380 °C, Babbitt microstructures are improved to be finer and more globular. On the other side pouring the Babbitt at low pouring temperature of 380 °C increases the chance of present higher unbonded area percent. Increasing the volume ratio of liquid to solid decreases the Sn-Pb interface thicknesses and increases the bonded interface area. In order to optimize the production of Babbitt-steel bimetal composite at low pouring temperature, the volume ratio of liquid Babbitt to solid steel shell should be higher value that could be more than 5 depending on the extrapolation of current data presented.

Effects of Cyclic Loading on the Deformation and Elastic-Plastic Fracture Behavior of a Cast Stainless Steel

DTIC Science & Technology

1991-10-01

23 8. High Cycle Fatigue Crack Growth Data for Cast Stainless Steel Showing Comparison with Rolfe and Barsom Fit .......... 24 9. Cyclic Load...compared to the Rolfe /Barsom4 fatigue crack propagation equation for austenitic stainless steels in Fig. 8. ELASTIC-PLASTIC Cyclic J-testing was...place during both the compression and tensile loadings. The J-integral was calculated on each cycle using the Merkle -Corten 9 J equation as modified by

A novel metal flow imaging using electrical capacitance tomography

NASA Astrophysics Data System (ADS)

Wondrak, Thomas; Soleimani, Manuchehr

2017-06-01

The measurement of gas-liquid metal two phase flow is a challenging task due to the opaqueness and the high temperatures. For instance, during continuous casting of steel the distribution of argon gas and liquid steel in the submerged entry nozzle is of high interest, since it influences the quality of the produced steel. In this paper we present the results of a feasibility study for applying the electrical capacitance tomography (ECT) to detect the outer surface of a liquid metal stream. The results of this study are the basis for the development of a new contactless sensor which should be able to detect the outer shape of a liquid metal jet using ECT and the bubbles inside the jet at the same time with mutual inductance tomography.

Numerical simulation of the solidification microstructure of a 17-4PH stainless steel investment casting and its experimental verification

NASA Astrophysics Data System (ADS)

Li, You Yun; Tsai, DeChang; Hwang, Weng Sing

2008-06-01

The purpose of this study is to develop a technique of numerically simulating the microstructure of 17-4PH (precipitation hardening) stainless steel during investment casting. A cellular automation (CA) algorithm was adopted to simulate the nucleation and grain growth. First a calibration casting was made, and then by comparing the microstructures of the calibration casting with those simulated using different kinetic growth coefficients (a2, a3) in CA, the most appropriate set of values for a2 and a3 would be obtained. Then, this set of values was applied to the microstructure simulation of a separate casting, where the casting was actually made. Through this approach, this study has arrived at a set of growth kinetic coefficients from the calibration casting: a2 is 2.9 × 10-5, a3 is 1.49 × 10-7, which is then used to predict the microstructure of the other test casting. Consequently, a good correlation has been found between the microstructure of actual 17-4PH casting and the simulation result.

Cast, heat-resistant austenitic stainless steels having reduced alloying element content

DOEpatents

Muralidharan, Govindarajan [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Pankiw, Roman I [Greensburg, PA

2011-08-23

A cast, austenitic steel composed essentially of, expressed in weight percent of the total composition, about 0.4 to about 0.7 C, about 20 to about 30 Cr, about 20 to about 30 Ni, about 0.5 to about 1 Mn, about 0.6 to about 2 Si, about 0.05 to about 1 Nb, about 0.05 to about 1 W, about 0.05 to about 1.0 Mo, balance Fe, the steel being essentially free of Ti and Co, the steel characterized by at least one microstructural component selected from the group consisting of MC, M.sub.23C.sub.6, and M(C, N).

Cast, heat-resistant austenitic stainless steels having reduced alloying element content

DOEpatents

Muralidharan, Govindarajan [Knoxville, TN; Sikka, Vinod Kumar [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN; Pankiw, Roman I [Greensburg, PA

2010-07-06

A cast, austenitic steel composed essentially of, expressed in weight percent of the total composition, about 0.4 to about 0.7 C, about 20 to about 30 Cr, about 20 to about 30 Ni, about 0.5 to about 1 Mn, about 0.6 to about 2 Si, about 0.05 to about 1 Nb, about 0.05 to about 1 W, about 0.05 to about 1.0 Mo, balance Fe, the steel being essentially free of Ti and Co, the steel characterized by at least one microstructural component selected from the group consisting of MC, M.sub.23C.sub.6, and M(C, N).

Experimental and Numerical Modeling of Fluid Flow Processes in Continuous Casting: Results from the LIMMCAST-Project

NASA Astrophysics Data System (ADS)

Timmel, K.; Kratzsch, C.; Asad, A.; Schurmann, D.; Schwarze, R.; Eckert, S.

2017-07-01

The present paper reports about numerical simulations and model experiments concerned with the fluid flow in the continuous casting process of steel. This work was carried out in the LIMMCAST project in the framework of the Helmholtz alliance LIMTECH. A brief description of the LIMMCAST facilities used for the experimental modeling at HZDR is given here. Ultrasonic and inductive techniques and the X-ray radioscopy were employed for flow measurements or visualizations of two-phase flow regimes occurring in the submerged entry nozzle and the mold. Corresponding numerical simulations were performed at TUBAF taking into account the dimensions and properties of the model experiments. Numerical models were successfully validated using the experimental data base. The reasonable and in many cases excellent agreement of numerical with experimental data allows to extrapolate the models to real casting configurations. Exemplary results will be presented here showing the effect of electromagnetic brakes or electromagnetic stirrers on the flow in the mold or illustrating the properties of two-phase flows resulting from an Ar injection through the stopper rod.

Engineering study for a melting, casting, rolling and fabrication facility for recycled contaminated stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This Preliminary Report is prepared to study the facilities required for recycling contaminated stainless steel scrap into plate which will be fabricated into boxes suitable for the storage of contaminated wastes and rubble. The study is based upon the underlying premise that the most cost effective way to produce stainless steel is to use the same processes employed by companies now in production of high quality stainless steel. Therefore, the method selected for this study for the production of stainless steel plate from scrap is conventional process using an Electric Arc Furnace for meltdown to hot metal, a Continuous Castermore » for production of cast slabs, and a Reversing Hot Mill for rolling the slabs into plate. The fabrication of boxes from the plate utilizes standard Shears, Punch Presses and welding equipment with Robotic Manipulators. This Study presumes that all process fumes, building dusts and vapors will be cycled through a baghouse and a nuclear grade HEPA filter facility prior to discharge. Also, all process waste water will be evaporated into the hot flue gas stream from the furnace utilizing a quench tank; so there will be no liquid discharges from the facility and all vapors will be processed through a HEPA filter. Even though HEPA filters are used today in controlling radioactive contamination from nuclear facilities there is a sparsity of data concerning radioactivity levels and composition of waste that may be collected from contaminated scrap steel processing. This report suggests some solutions to these problems but it is recommended that additional study must be given to these environmental problems.« less

Changes Found on Run-In and Scuffed Surfaces of Steel Chrome Plate, and Cast Iron

NASA Technical Reports Server (NTRS)

Good, J. N.; Godfrey, Douglas

1947-01-01

A study was made of run-in and scuffed steel, chrome-plate, and cast-iron surfaces. X-ray and electron diffraction techniques, micro-hardness determinations, and microscopy were used. Surface changes varied and were found to include three classes: chemical reaction, hardening, and crystallite-size alteration. The principal chemical reactions were oxidation and carburization.

Irradiation response of delta ferrite in as-cast and thermally aged cast stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Zhangbo; Lo, Wei-Yang; Chen, Yiren

To enable the life extension of Light Water Reactors (LWRs) beyond 60 years, it is critical to gain adequate knowledge for making conclusive predictions to assure the integrity of duplex stainless steel reactor components, e.g. primary pressure boundary and reactor vessel internal. Microstructural changes in the ferrite of thermally aged, neutron irradiated only, and neutron irradiated after being thermally aged cast austenitic stainless steels (CASS) were investigated using atom probe tomography. The thermal aging was performed at 400 °C for 10,000 h and the irradiation was conducted in the Halden reactor at ~315 °C to 0.08 dpa (5.6 × 10more » 19 n/cm 2 E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 × 10 -9 dpa/s was found to induce spinod,al decomposition in the ferrite of as-cast microstructure, and further to enhance the spinodal decomposition in the thermally aged cast alloys. Regarding the G-phase precipitates, the neutron irradiation dramatically increases the precipitate size, and alters the composition of the precipitates with increased, Mn, Ni, Si and Mo and reduced Fe and Cr contents. Lastly, The results have shown that low dose neutron irradiation can further accelerate the degradation of ferrite in a duplex stainless steel at the LWR relevant condition.« less

Irradiation response of delta ferrite in as-cast and thermally aged cast stainless steel

DOE PAGES

Li, Zhangbo; Lo, Wei-Yang; Chen, Yiren; ...

2015-08-08

To enable the life extension of Light Water Reactors (LWRs) beyond 60 years, it is critical to gain adequate knowledge for making conclusive predictions to assure the integrity of duplex stainless steel reactor components, e.g. primary pressure boundary and reactor vessel internal. Microstructural changes in the ferrite of thermally aged, neutron irradiated only, and neutron irradiated after being thermally aged cast austenitic stainless steels (CASS) were investigated using atom probe tomography. The thermal aging was performed at 400 °C for 10,000 h and the irradiation was conducted in the Halden reactor at ~315 °C to 0.08 dpa (5.6 × 10more » 19 n/cm 2 E > 1 MeV). Low dose neutron irradiation at a dose rate of 5 × 10 -9 dpa/s was found to induce spinod,al decomposition in the ferrite of as-cast microstructure, and further to enhance the spinodal decomposition in the thermally aged cast alloys. Regarding the G-phase precipitates, the neutron irradiation dramatically increases the precipitate size, and alters the composition of the precipitates with increased, Mn, Ni, Si and Mo and reduced Fe and Cr contents. Lastly, The results have shown that low dose neutron irradiation can further accelerate the degradation of ferrite in a duplex stainless steel at the LWR relevant condition.« less

Influence of tray rigidity and impression technique on accuracy of polyvinyl siloxane impressions.

PubMed

Hoyos, Alex; Soderholm, Karl-Johan

2011-01-01

The aim of this study was to determine how tray rigidity and impression technique affect the accuracy of polyvinyl siloxane impressions. Disposable plastic trays and metallic Rim-Lock trays were used in combination with a heavy/light body technique or with two different putty-wash techniques. For each technique-tray combination, 10 impressions were made of a master cast with two steel abutments representing the mandibular right first premolar and second molar, between which a steel rod was placed at the ridge level. Each steel abutment had five marks, while the steel rod in between the two abutments had only one mark, which served as a reference point. With a universal measuring microscope, the x-, y-, and z-coordinates were recorded for each mark on the master cast and impressions. The distances between the different marks and the reference point on the impressions were calculated and compared with those of the master cast. All techniques used with the plastic trays had distances that were significantly different from the master cast (P < .05), while for the metal trays, it was only the heavy/light body technique that resulted in distances that were significantly different from the master cast (P < .05). Plastic trays produced less accurate impressions than metal trays. When metal trays were used, putty-based impressions were dimensionally better than heavy/light body impressions.

The erosion resistance of tool alloys in foundry melt the Zamak 4 - 1

NASA Astrophysics Data System (ADS)

Muhametzyanova, GF; Kolesnikov, M. S.; Muhametzyanov, I. R.

2016-06-01

The paper considers the resistance against erosion dissolution in the melt of foundry Zamak 4 - 1 die steels used for press machine parts manufacturing for injection molding, and hard alloys system WC - Co. It is established that the solubility in the melt Zamak - 4 - 1 steel of 4H5MFS and DI - 22 are promising for the parts fabrication of metal-wire casting machines of CLT and IDRA types. A significant reserve to increase the resistance of metal wires is the use of cast steel, as well as in electroslag and electro-beam remelting options. Metal-ceramic alloy doped with chromium VK25H may be recommended for reinforcement of heavily loaded parts of the press-nodes of hot casting machines under pressure.

Performance of prestressed girders cast with LWSCC.

DOT National Transportation Integrated Search

2012-08-01

Bond of prestressing steel has been a much debated topic since the 1950s. Limited data are available on the transfer and development length of strands cast in self : consolidating concrete (SCC) and even less for strands cast in light weight, self-co...

The Effects of Casting Porosity on the Tensile Behavior of Investment Cast 17-4PH Stainless Steel

NASA Astrophysics Data System (ADS)

Susan, D. F.; Crenshaw, T. B.; Gearhart, J. S.

2015-08-01

The effect of casting porosity on the mechanical behavior of investment cast 17-4PH stainless steel was studied as well as the effect of heat treatment on the alloy's sensitivity to casting defects. Interdendritic porosity, formed during solidification and shrinkage of the alloy, reduces the yield strength and ultimate tensile strength roughly in proportion to the reduction in load bearing cross-section. The effects of casting porosity on ductility (% strain, % reduction in area) are more severe, in agreement with research on other alloy systems. In this study, 10% porosity reduced the ductility of 17-4PH stainless steel by almost 80% for the high-strength H925 condition. Tensile testing at -10°C (263 K) further reduces the alloy ductility with and without pores present. In the lower strength H1100 condition, the ductility is higher than the H925 condition, as expected, and somewhat less sensitive to porosity. By measuring the area % porosity on the fracture surface of tensile specimens, the trend in failure strain versus area % porosity was obtained and analyzed using two methods: an empirical approach to determine an index of defect susceptibility with a logarithmic fit and an analytical approach based on the constitutive stress-strain behavior and critical strain concentration in the vicinity of the casting voids. The applicability of the second method depends on the amount of non-uniform strain (necking) and, as such, the softer H1100 material did not correlate well to the model. The behavior of 17-4PH was compared to previous work on cast Al alloys, Mg alloys, and other cast materials.

Formation of Widmanstätten Austenite in Strip Cast Grain-Oriented Silicon Steel

NASA Astrophysics Data System (ADS)

Song, Hong-Yu; Liu, Hai-Tao; Wang, Guo-Dong; Jonas, John J.

2017-04-01

The formation of Widmanstätten austenite was studied in strip cast grain-oriented silicon steel. The microstructure was investigated by optical microscopy and scanning electron microscopy. The orientations of the ferrite, Widmanstätten austenite, and martensite were determined using electron backscatter diffraction. The Widmanstätten austenite exhibits a lath-like shape and nucleates directly on the ferrite grain boundaries. This differs significantly from earlier work on duplex stainless steels. The orientation relationship between the Widmanstätten austenite and the parent ferrite is closer to Kurdjumov-Sachs than to Nishiyama-Wassermann. The ferrite boundaries migrate so as to accommodate the habit planes of the laths, leading to the presence of zigzag boundaries in the as-cast strip. Carbon partitioning into the Widmanstätten austenite and silicon partitioning into the parent ferrite were observed.

49 CFR 179.400-5 - Materials.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-5 Materials. (a) Stainless steel of ASTM A 240/A 240M (IBR, see § 171.7 of this subchapter), Type 304 or 304L must be used... the lading. (b) Any steel casting, steel forging, steel structural shape or carbon steel plate used to...

49 CFR 179.400-5 - Materials.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-5 Materials. (a) Stainless steel of ASTM A 240/A 240M (IBR, see § 171.7 of this subchapter), Type 304 or 304L must be used... the lading. (b) Any steel casting, steel forging, steel structural shape or carbon steel plate used to...

49 CFR 179.400-5 - Materials.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-5 Materials. (a) Stainless steel of ASTM A 240/A 240M (IBR, see § 171.7 of this subchapter), Type 304 or 304L must be used... the lading. (b) Any steel casting, steel forging, steel structural shape or carbon steel plate used to...

49 CFR 179.400-5 - Materials.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-5 Materials. (a) Stainless steel of ASTM A 240/A 240M (IBR, see § 171.7 of this subchapter), Type 304 or 304L must be used... the lading. (b) Any steel casting, steel forging, steel structural shape or carbon steel plate used to...

Non-Magnetic, Tough, Corrosion- and Wear-Resistant Knives From Bulk Metallic Glasses and Composites

NASA Technical Reports Server (NTRS)

Hoffman, Douglas C.; Potter, Benjamin

2013-01-01

Quality knives are typically fabricated from high-strength steel alloys. Depending on the application, there are different requirements for mechanical and physical properties that cause problems for steel alloys. For example, diver's knives are generally used in salt water, which causes rust in steel knives. Titanium diver's knives are a popular alternative due to their salt water corrosion resistance, but are too soft to maintain a sharp cutting edge. Steel knives are also magnetic, which is undesirable for military applications where the knives are used as a tactical tool for diffusing magnetic mines. Steel is also significantly denser than titanium (8 g/cu cm vs. 4.5 g/cu cm), which results in heavier knives for the same size. Steel is hard and wear-resistant, compared with titanium, and can keep a sharp edge during service. A major drawback of both steel and titanium knives is that they must be ground or machined into the final knife shape from a billet. Since most knives have a mirrored surface and a complex shape, manufacturing them is complex. It would be more desirable if the knife could be cast into a net or near-net shape in a single step. The solution to the deficiencies of titanium, steel, and ceramic knives is to fabricate them using bulk metallic glasses (or composites). These alloys can be cast into net or near-net shaped knives with a combination of properties that exceed both titanium and steel. A commercially viable BMG (bulk metallic glass) or composite knife is one that exhibits one or all of the following properties: It is based on titanium, has a self-sharpening edge, can retain an edge during service, is hard, is non-magnetic, is corrosion-resistant against a variety of corrosive environments, is tough (to allow for prying), can be cast into a net-shape with a mirror finish and a complex shape, has excellent wear resistance, and is low-density. These properties can be achieved in BMG and composites through alloy chemistry and processing. For each desired property for knife fabrication and performance, there is an alloy development strategy that optimizes behavior. Although BMG knives have been demonstrated as far back as 1995, they never found commercial success because they had to be ground (which presented problems because the alloys contained beryllium), they weren't low cost (because they weren't cast to a net-shape), they were brittle (because they were made with a low-quality commercial material), and they had extremely poor corrosion resistance (because corrosion was not well-understood in these materials). Ultimately, these shortcomings prevented the widespread commercialization. In the current work, the inventors have applied more than a decade of research on BMGs from Caltech and JPL to develop a better understanding of how to make BMG knives that exhibit an optimal combination of properties, processing and cost. Alloys have been developed based in titanium (and other metals), that exhibit high toughness, high hardness, excellent corrosion resistance, no ferromagnetism, edge-retaining selfsharpening, and the ability to be cast like a plastic using commercially available casting techniques (currently used by commercial companies such as Liquidmetal Technologies and Visser Precision Casting). The inventors argue that depending on the application (diving, military, tactical, utility, etc.) there is an optimal combination of design and alloy composition. Moreover, with new casting technologies not available at the inception of these materials, net-shaped knives can be cast into complex shapes that require no aftermarket forming, except for sharpening using water-cooled polishing wheel. These combinations of discoveries seek to make low-cost BMG knives commercially viable products that have no equal among metal or ceramic knives. Current work at JPL focuses on net-shape casting of these alloys and testing their mechanical properties versus commercially available knives to demonstrate their benefits.

Metallographic examination of the structure of the metal of cold arms of the nineteenth-early twentieth centuries made at the Zlatoust arms factory

NASA Astrophysics Data System (ADS)

Schastlivtsev, V. M.; Rodionov, D. P.; Gerasimov, V. Yu.; Khlebnikova, Yu. V.

2010-11-01

Data are given concerning the structure and the chemical composition of carbon steel used for making cold arms, which was produced at the Zlatoust arms factory in the nineteenth and early twentieth centuries. The results of the analysis of the structure of metal demonstrates the general trend of the development of metallurgy both at the Ural plants and in the world: from the creation of the crucible methods of production of cast steel to the mass production of cast steel by the Bessemer and Martin methods.

Advances in multi-scale modeling of solidification and casting processes

NASA Astrophysics Data System (ADS)

Liu, Baicheng; Xu, Qingyan; Jing, Tao; Shen, Houfa; Han, Zhiqiang

2011-04-01

The development of the aviation, energy and automobile industries requires an advanced integrated product/process R&D systems which could optimize the product and the process design as well. Integrated computational materials engineering (ICME) is a promising approach to fulfill this requirement and make the product and process development efficient, economic, and environmentally friendly. Advances in multi-scale modeling of solidification and casting processes, including mathematical models as well as engineering applications are presented in the paper. Dendrite morphology of magnesium and aluminum alloy of solidification process by using phase field and cellular automaton methods, mathematical models of segregation of large steel ingot, and microstructure models of unidirectionally solidified turbine blade casting are studied and discussed. In addition, some engineering case studies, including microstructure simulation of aluminum casting for automobile industry, segregation of large steel ingot for energy industry, and microstructure simulation of unidirectionally solidified turbine blade castings for aviation industry are discussed.

Top-lateral bracing systems for trapezoidal steel box-girder bridges.

DOT National Transportation Integrated Search

2005-08-01

Trapezoidal steel box girders are becoming increasingly popular as a bridge system due to their torsional efficiency and aesthetic appearance. These bridge systems utilize one or more trapezoidal steel girders with a cast-in-place composite concrete ...

Mechanical and Microstructural Effects of Thermal Aging on Cast Duplex Stainless Steels by Experiment and Finite Element Method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schwarm, Samuel C.; Mburu, Sarah N.; Kolli, Ratna P.

Cast duplex stainless steel piping in light water nuclear reactors expe- rience thermal aging embrittlement during operational service. Interest in extending the operational life to 80 years requires an increased understanding of the microstructural evolution and corresponding changes in mechanical behavior. We analyze the evolution of the microstructure during thermal aging of cast CF-3 and CF-8 stainless steels using electron microscopy and atom probe tomography. The evolution of the mechanical properties is measured concurrently by mechanical methods such as tensile tests, Charpy V-notch tests, and instrumented nanoinden- tation. A microstructure-based finite element method model is developed and uti- lized inmore » conjunction with the characterization results in order to correlate the local stress-strain effects in the microstructure with the bulk measurements. This work is supported by the DOE Nuclear Energy University Programs (NEUP), contract number DE-NE0000724.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

John N. DuPont; Jeffrey D. Farren; Andrew W. Stockdale

It is commonly believed that high alloy steel castings have inferior corrosion resistance to their wrought counterparts as a result of the increased amount of microsegregation remaining in the as-cast structure. Homogenization and dissolution heat treatments are often utilized to reduce or eliminate the residual microsegregation and dissolve the secondary phases. Detailed electron probe microanalysis (EPMA) and light optical microscopy (LOM) were utilized to correlate the amount of homogenization and dissolution present after various thermal treatments with calculated values and with the resultant corrosion resistance of the alloys.The influence of heat treatment time and temperature on the homogenization and dissolutionmore » kinetics were investigated using stainless steel alloys CN3MN and CK3MCuN. The influence of heat treatment time and temperature on the impact toughness and corrosion reistance of cast stainless steel alloys CF-3, CF-3M, CF-8, and CF-8M was also investigated.« less

Study of Inclusion Bands in Continuously Cast Steel Billets for Rolling Thermomechanically Treated Rebars

NASA Astrophysics Data System (ADS)

Pandey, J. C.; Choubey, P. N.; Raj, Manish

2008-07-01

The article presents the investigation results of inclusion bands generally formed toward the loose end/inner radius of continuously cast (CC) strands of thermomechanically treated (TMT) rebar grade cast through curved molds. The main analytical tool used for this purpose was an ultrasonic C-scan image analysis system to reveal this band, and the defects detected in this band using the preceding technique were further measured and analyzed in an optical microscope and a scanning electron microscope (SEM) using energy-dispersive system (EDS). The investigation results revealed the presence of macrolevel globular macroinclusions in the size range 50 to 711 μm. The main constituents of the globular inclusions were found to be SiO2 and MnO. Impact test results revealed reduction in ductility in these bands when compared with the billet material without inclusion band toward the opposite face from the inner radius face. In Charpy testing, reduction in the impact energy in these bands was found to be 0.2 kg m. It is important to monitor the severity of macroinclusions present in these bands to avoid the cracking of TMT rebars during hot rolling.

Forging Oxide-Dispersion-Strengthened Superalloys

NASA Technical Reports Server (NTRS)

Harf, F. H.; Glasgow, T. K.; Moracz, D. J.; Austin, C. M.

1986-01-01

Cladding of mild steel prevents surface cracking when alloy contacts die. Continual need for improvements in properties of alloys capable of withstanding elevated temperatures. Accomplished by using oxide-dispersion-strengthed superalloys such as Inconel Alloy MA 6000. Elevated tensile properties of forged alloy equal those of hot-rolled MA 6000 bar. Stress-rupture properties somewhat lower than those of bar stock but, at 1,100 degrees C, exceed those of strongest commercial single crystal, directionally solidified and conventionally cast superalloys.

Large Eddy Simulation of Transient Flow, Solidification, and Particle Transport Processes in Continuous-Casting Mold

NASA Astrophysics Data System (ADS)

Liu, Zhongqiu; Li, Linmin; Li, Baokuan; Jiang, Maofa

2014-07-01

The current study developed a coupled computational model to simulate the transient fluid flow, solidification, and particle transport processes in a slab continuous-casting mold. Transient flow of molten steel in the mold is calculated using the large eddy simulation. An enthalpy-porosity approach is used for the analysis of solidification processes. The transport of bubble and non-metallic inclusion inside the liquid pool is calculated using the Lagrangian approach based on the transient flow field. A criterion of particle entrapment in the solidified shell is developed using the user-defined functions of FLUENT software (ANSYS, Inc., Canonsburg, PA). The predicted results of this model are compared with the measurements of the ultrasonic testing of the rolled steel plates and the water model experiments. The transient asymmetrical flow pattern inside the liquid pool exhibits quite satisfactory agreement with the corresponding measurements. The predicted complex instantaneous velocity field is composed of various small recirculation zones and multiple vortices. The transport of particles inside the liquid pool and the entrapment of particles in the solidified shell are not symmetric. The Magnus force can reduce the entrapment ratio of particles in the solidified shell, especially for smaller particles, but the effect is not obvious. The Marangoni force can play an important role in controlling the motion of particles, which increases the entrapment ratio of particles in the solidified shell obviously.

Development of refractories and related products for steel melting, finishing, and casting

NASA Astrophysics Data System (ADS)

Smirnov, A. N.

2013-06-01

The transformation of the consumption of refractories for the production, out-of-furnace treatment, and casting of steel is considered. The main trends in developing the refractory market are shown to be a significant decrease in the specific consumption of refractories per 1 t liquid steel and the predominant application of refractories based on magnesia raw materials and fused corundum for the working layers of melting units, ladles, and tundishes. The main trend in decreasing the specific costs of refractories is the development of refractories based on alternative sources of raw materials, which are cheaper and more available for refractory manufacturers.

Computational Fluid Dynamics Modeling of Macrosegregation and Shrinkage in Large-Diameter Steel Roll Castings

NASA Astrophysics Data System (ADS)

Nastac, Laurentiu

2011-12-01

Minimizing macrosegregation and shrinkage in large cast steel mill rolls challenges the limits of commercial foundry technology. Processing improvements have been achieved by balancing the total heat input of casting with the rate of heat extraction from the surface of the roll in the mold. A submerged entry nozzle (SEN) technique that injects a dilute alloy addition through a nozzle into the partially solidified net-shaped roll ingot can mitigate both centerline segregation and midradius channel segregate conditions. The objective of this study is to optimize the melt chemistry, solidification, and SEN conditions to minimize centerline and midradius segregation, and then to improve the quality of the transition region between the outer shell and the diluted interior region. To accomplish this objective, a multiphase, multicomponent computational fluid dynamics (CFD) code was developed for studying the macrosegregation and shrinkage under various casting conditions for a 65-ton, 1.6-m-diameter steel roll. The developed CFD framework consists of solving for the volume fraction of phases (air and steel mixture), temperature, flow, and solute balance in multicomponent alloy systems. Thermal boundary conditions were determined by measuring the temperature in the mold at several radial depths and height locations. The thermophysical properties including viscosity of steel alloy used in the simulations are functions of temperature. The steel mixture in the species-transfer model consists of the following elements: Fe, Mn, Si, S, P, C, Cr, Mo, and V. Density and liquidus temperature of the steel mixture are locally affected by the segregation of these elements. The model predictions were validated against macrosegregation measured from pieces cut from the 65-ton roll. The effect of key processing parameters such as melt composition and superheat of both the shell and the dilute interior alloy are addressed. The influence of mold type and thickness on macrosegregation and shrinkage also are discussed.

Corrosion protection of low-carbon steel using exopolysaccharide coatings from Leuconostoc mesenteroides.

PubMed

Finkenstadt, Victoria L; Côté, Gregory L; Willett, J L

2011-06-01

Corrosion of metals is a serious and challenging problem faced worldwide by industry. Purified Leuconostoc mesenteroides exopolysaccharide (EPS) coatings, cast from aqueous solution, inhibited the corrosion of low-carbon steel as determined by electrochemical impedance spectroscopy (EIS). There were two different corrosion behaviors exhibited when EPS films from different strains were cast onto the steel. One EPS coating reacted immediately with the steel substrate to form an iron (III) oxide layer ("rust") during the drying process while another did not. The samples that did not flash corrode had higher corrosion inhibition and formed an iron (II) passivation layer during EIS testing that persisted after the cells were disassembled. Corrosion inhibition was strain-specific as polysaccharides with similar structure did not have the same corrosion potential.

9. VIEW SHOWING JUNCTION OF CONCRETE EAST APPROACH SPAN WITH ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

9. VIEW SHOWING JUNCTION OF CONCRETE EAST APPROACH SPAN WITH STEEL SPAN, LOOKING NORTH. NOTE ROCKING CAST STEEL SHOE ATTACHED TO PIER TO ALLOW FOR EXPANSION OF STEEL SPAN - Jensen Bridge, Spanning Green River at Town of Jensen, Jensen, Uintah County, UT

Behaviour of Steel Fibre Reinforced Rubberized Continuous Deep Beams

NASA Astrophysics Data System (ADS)

Sandeep, MS; Nagarajan, Praveen; Shashikala, A. P.

2018-03-01

Transfer girders and pier caps, which are in fact deep beams, are critical structural elements present in high-rise buildings and bridges respectively. During an earthquake, failure of lifeline structures like bridges and critical structural members like transfer girders will result in severe catastrophes. Ductility is the key factor that influences the resistance of any structural member against seismic action. Structural members cast using materials having higher ductility will possess higher seismic resistance. Previous research shows that concrete having rubber particles (rubcrete) possess better ductility and low density in comparison to ordinary concrete. The main hindrance to the use of rubcrete is the reduction in compressive and tensile strength of concrete due to the presence of rubber. If these undesirable properties of rubcrete can be controlled, a new cementitious composite with better ductility, seismic performance and economy can be developed. A combination of rubber particles and steel fibre has the potential to reduce the undesirable effect of rubcrete. In this paper, the effect of rubber particles and steel fibre in the behaviour of two-span continuous deep beams is studied experimentally. Based on the results, optimum proportions of steel fibre and rubber particles for getting good ductile behaviour with less reduction in collapse load is found out.

Report on Northwestern's Air-cooled, Copper Precipitation Hardened, High Strength, Weldable Steel Cast and Hot Rolled at Oregon Steel Mills

DOT National Transportation Integrated Search

1996-09-27

This research has shown that a Grade 70 construction steel of 1/2- to 1-inch plate thicknesses can be produced without a quench and temper or accelerated cooling from hot-rolling if the Cu content in the steel is sufficiently high. Coherent very fine...

Effect of substrates on microstructure and mechanical properties of nano-eutectic 1080 steel produced by aluminothermic reaction

DOE Office of Scientific and Technical Information (OSTI.GOV)

La, Peiqing, E-mail: pqla@lut.cn; Li, Zhengning; Li, Cuiling

2014-06-01

Nano-eutectic bulk 1080 carbon steel was prepared on glass and copper substrates by an aluminothermic reaction casting. The microstructure of the steel was analyzed by an optical microscope, transmission electron microscopy, an electron probe micro-analyzer, a scanning electron microscope and X-ray diffraction. Results show that the microstructure of the steel consisted of a little cementite and lamellar eutectic pearlite. Average lamellar spacing of the pearlite prepared on copper and glass substrates was about 230 nm and 219 nm, respectively. Volume fraction of the pearlite of the two steels was about 95%. Hardness of the steel was about 229 and 270more » HV. Tensile strength was about 610 and 641 MPa and tensile elongation was about 15% and 8%. Compressive strength was about 1043 and 1144 MPa. Compared with the steel prepared on copper substrate, the steel prepared on glass substrate had smaller lamellar spacing of the pearlite phase and higher strength, and low ductility due to the smaller spacing. - Highlights: • 1080-carbon steels were successfully prepared by an aluminothermic reaction casting. • Lamellar spacing of the nanoeutetic pearlite is less than 250 nm. • The compressive strength of the steel is about 1144 MPa. • The tensile ductility of the steel is about 15%.« less

MLEP-Fail calibration for 1/8 inch thick cast plate of 17-4 steel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corona, Edmundo

The purpose of the work presented in this memo was to calibrate the Sierra material model Multilinear Elastic-Plastic Hardening Model with Failure (MLEP-Fail) for 1/8 inch thick cast plate of 17-4 steel. The calibration approach is essentially the same as that recently used in a previous memo using data from smooth and notched tensile specimens. The notched specimens were manufactured with three notch radii R = 1=8, 1/32 and 1/64 inches. The dimensions of the smooth and notched specimens are given in the prints in Appendix A. Two cast plates, Plate 3 and Plate 4, with nominally identical properties weremore » considered.« less

Effect of Casting Defect on Mechanical Properties of 17-4PH Stainless Steel

NASA Astrophysics Data System (ADS)

Kim, Jong-Yup; Lee, Joon-Hyun; Nahm, Seung-Hoon

Damage and integrity evaluation techniques should be developed steadily in order to ensure the reliability and the economic efficiency of gas turbine engines. Casting defects may exist in most casting components of gas turbine engines, and the defects could give serious effect on mechanical properties and fracture toughness. Therefore, it is very important to understand the effect of casting defects on the above properties in order to predict the safety and life of components. In this study, specimens with internal casting defects, made from 17-4PH stainless steel, were prepared and evaluated and characterized based on the volume fraction of defects. The relation between mechanical properties such as tensile, low cycle fatigue and fracture toughness and volume fraction of defect has been investigated. As a result of the analysis, the mechanical properties of 17-4PH decreased as the defect volume fraction increased with very good linearity. The mechanical properties also showed an inversely proportional relationship to electrical resistivity.

Wear resistance of metals and alloys; Proceedings of the Conference, Chicago, IL, Sept. 24-30, 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kingsbury, G.R.

1988-01-01

Techniques for characterizing and improving the wear properties of metals and composites are discussed in reviews and reports. Topics addressed include the use of interatomic potentials to study the relationship between abrasive wear and other mechanical properties, gas-detonation powder spraying of diamond coatings, a fluidized-bed test method for erosion resistance, the wear behavior of Al and Al-Si-Cu alloys, and abrasive wear of bronze and ZA alloys with and without lubrication. Consideration is given to continuously cast vs sand-cast Zn-Al alloys for bearings, sintered 6061 Al-alloy-based particulate composites with dry lubricants, Cu-based particulate composites, high-temperature friction and wear of X-750 andmore » X-188 superalloys for low-heat-rejection engines, a new metallurgical conception of wear-resistant steels, and the effect of matrix microstructure on the abrasion resistance of high-Cr white cast irons. Extensive graphs and micrographs are provided.« less

Development of Creep-Resistant and Oxidation-Resistant Austenitic Stainless Steels for High Temperature Applications

NASA Astrophysics Data System (ADS)

Maziasz, Philip J.

2018-01-01

Austenitic stainless steels are cost-effective materials for high-temperature applications if they have the oxidation and creep resistance to withstand prolonged exposure at such conditions. Since 1990, Oak Ridge National Laboratory (ORNL) has developed advanced austenitic stainless steels with creep resistance comparable to Ni-based superalloy 617 at 800-900°C based on specially designed "engineered microstructures" utilizing a microstructure/composition database derived from about 20 years of radiation effect data on steels. The wrought high temperature-ultrafine precipitate strengthened (HT-UPS) steels with outstanding creep resistance at 700-800°C were developed for supercritical boiler and superheater tubing for fossil power plants in the early 1990s, the cast CF8C-Plus steels were developed in 1999-2001 for land-based gas turbine casing and diesel engine exhaust manifold and turbocharger applications at 700-900°C, and, in 2015-2017, new Al-modified cast stainless steels with oxidation and creep resistance capabilities up to 950-1000°C were developed for automotive exhaust manifold and turbocharger applications. This article reviews and summarizes their development and their properties and applications.

42. Casting floor, "B" furnace, pour in progress; mudgun is ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

42. Casting floor, "B" furnace, pour in progress; mudgun is to right of furnace; operator takes temperature of iron in trough during pout. Looking south - Rouge Steel Company, 3001 Miller Road, Dearborn, MI

Rapid Cycle Casting of Steel

DTIC Science & Technology

1981-07-01

C’, and at temperature T, are Infiltrated by !L amougt of liquid of composition C’., such that ,C, 4 f+.C’L - X. V. 7 average carbon content of the...maximum liquid penetration was 100 mm at an infiltration pressure of 755 kPa. The average casting composition was 0.94 w/o carbon . The segregation at...content* at four casting locations. 2. Results The casting composition ( carbon content) as a function of casting location is given in Table D-IV. The

New sulphiding method for steel and cast iron parts

NASA Astrophysics Data System (ADS)

Tarelnyk, V.; Martsynkovskyy, V.; Gaponova, O.; Konoplianchenko, Ie; Dovzyk, M.; Tarelnyk, N.; Gorovoy, S.

2017-08-01

A new method for sulphiding steel and cast iron part surfaces by electroerosion alloying (EEA) with the use of a special electrode is proposed, which method is characterized in that while manufacturing the electrode, on its surface, in any known manner (punching, threading, pulling, etc.), there is formed at least a recess to be filled with sulfur as a consistent material, and then there is produced EEA by the obtained electrode without waiting for the consistent material to become dried.

Heat treatment giving a stable high temperature micro-structure in cast austenitic stainless steel

DOEpatents

Anton, Donald L.; Lemkey, Franklin D.

1988-01-01

A novel micro-structure developed in a cast austenitic stainless steel alloy and a heat treatment thereof are disclosed. The alloy is based on a multicomponent Fe-Cr-Mn-Mo-Si-Nb-C system consisting of an austenitic iron solid solution (.gamma.) matrix reinforced by finely dispersed carbide phases and a heat treatment to produce the micro-structure. The heat treatment includes a prebraze heat treatment followed by a three stage braze cycle heat treatment.

Development of Integrated Die Casting Process for Large Thin-Wall Magnesium Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carter, Jon T.; Wang, Gerry; Luo, Alan

The purpose of this project was to develop a process and product which would utilize magnesium die casting and result in energy savings when compared to the baseline steel product. The specific product chosen was a side door inner panel for a mid-size car. The scope of the project included: re-design of major structural parts of the door, design and build of the tooling required to make the parts, making of parts, assembly of doors, and testing (both physical and simulation) of doors. Additional work was done on alloy development, vacuum die casting, and overcasting, all in order to improvemore » the performance of the doors and reduce cost. The project achieved the following objectives: 1. Demonstrated ability to design a large thin-wall magnesium die casting. 2. Demonstrated ability to manufacture a large thin-wall magnesium die casting in AM60 alloy. 3. Tested via simulations and/or physical tests the mechanical behavior and corrosion behavior of magnesium die castings and/or lightweight experimental automotive side doors which incorporate a large, thin-wall, powder coated, magnesium die casting. Under some load cases, the results revealed cracking of the casting, which can be addressed with re-design and better material models for CAE analysis. No corrosion of the magnesium panel was observed. 4. Using life cycle analysis models, compared the energy consumption and global warming potential of the lightweight door with those of a conventional steel door, both during manufacture and in service. Compared to a steel door, the lightweight door requires more energy to manufacture but less energy during operation (i.e., fuel consumption when driving vehicle). Similarly, compared to a steel door, the lightweight door has higher global warming potential (GWP) during manufacture, but lower GWP during operation. 5. Compared the conventional magnesium die casting process with the “super-vacuum” die casting process. Results achieved with cast tensile bars suggest some improvement in tensile properties with vacuum casting. Plant trials with large castings revealed cavity fill issues attributed to cooling and partial solidification of metal in the shot sleeve while waiting for vacuum to be established in the die cavity. 6. Developed age-hardenable Mg-based alloys as potential alternatives to the AM60 and AZ91 alloys typically used in automotive applications. Mg-7%Al-based alloys having Sn or Sn+Si additions exhibited significant age hardening, but more work is needed to demonstrate significant improvement in tensile properties. Corrosion behavior of these alloys is between those of AM60 and AZ91 alloys. 7. Evaluated the die casting of magnesium directly onto either steel or aluminum tubes as a potential process to make large lightweight subassemblies. Samples were free of gross defects, but additional work is needed to increase the interfacial shear strength. Overall, the project demonstrated that an automotive door-in-white design incorporating a die cast magnesium inner panel and a stamped aluminum outer panel can achieve approximately 50% mass reduction compared to the stamped steel baseline door-in-white. This leads to reduced energy consumption when driving the vehicle, which should more than offset the increased embedded energy of manufacture associated with the lighter metals. However, additional design work would be needed in order to meet the mechanical performance required of a door. Development of high-strength, high-ductility magnesium alloy castings would help make this technology more attractive for potential use in the side doors on automobiles. Also, increased use of recycled magnesium and aluminum would reduce the embedded energy and greenhouse gas emissions associated with the manufacture of this type of lightweight door. Commercialization planning of the type of lightweight door technology addressed in this project would be contingent upon the doors meeting all technical performance requirements of the car maker. The specific lightweight door developed in this project didn’t meet some of those requirements, but a preliminary business case study was conducted anyhow. This study considered the ratio of cost increase to mass decrease when the lightweight door is compared to a baseline steel door. The ratio was found to be in an acceptable range for some vehicle programs, especially if the number of such vehicles to be produced is equal to or slightly less than the estimated 250,000-shot life of the die set. This would allow for the investment in the dies to be spread across many parts and thereby help minimize the cost increase.« less

Thermophysical and Electronic Properties of Foreign Nonstainless Alloy Steels, Carbon Steels, and Cast Irons, A Comprehensive Survey of the World Literature,

DTIC Science & Technology

1981-11-01

PHYSICAL P;OPkRTIES CF ANTIMONY CAST IRONS. LONDON UNIV.. LONOCN. ENGLAND, PH.O. THESIS PI#UI.,V M K VAfAGIN MA M 1-79 1938 RU.IAN ATIAb PUOflsCTION 1...SURFACE TENCIC. PF LYCUIE ’ CFt AELC5. i𔄀-iC, ±9717 FOR OMZINAL ZEE T74161 I K.INl. V. CC. ANT. CONE. C. TECHP-OL. IRON STEEL IT ?4󈧏 1FT. 1 1 ~-i 971...978. A7 .-IG- PRESSURES 4143 TME EAIHS-.S COME. T4’%Lov. G. 10950617 Ur.;V. ;ALIFORNIA, LIVERMORE. PP-. JI. THESIS EFFECT OF TEMPERING ON GNINDING

Investigation on Simultaneous Effects of Shot Peen and Austenitizing Time and Temperature on Grain Size and Microstructure of Austenitic Manganese Steel (Hadfield)

NASA Astrophysics Data System (ADS)

Beheshti, M.; Zabihiazadboni, M.; Ismail, M. C.; Kakooei, S.; Shahrestani, S.

2018-03-01

Optimal conditions to increase life time of casting parts have been investigated by applying various cycles of heat treatment and shot peening on Hadfield steel surface. Metallographic and SEM microstructure examinations were used to determine the effects of shot peen, austenitizing time and temperature simultaneously. The results showed that with increasing austenitizing time and temperature of casting sample, carbides resolved in austenite phase and by further increase of austenitizing temperature and time, the austenite grain size becomes larger. Metallographic images illustrated that shot peening on Hadfield steel surface; Austenite - Martensite transformation has not occurred, but its matrix hardened through twining formation process.

75 FR 20335 - Certain Oil Country Tubular Goods from the People's Republic of China: Final Determination of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-04-19

... tubing, of iron (other than cast iron) or steel (both carbon and alloy), whether seamless or welded... Seamless Tube Mill of Inner Mongolia Baotou Steel 29.94 and Trading Co., Ltd Union Co., Ltd.\\27\\ Benxi... Century Machinery Co. Ltd.;Tianjin Seamless Steel Pipe Plant; Baoshan Iron & Steel Co. Ltd Shengli...

Predictive Capabilities of Multiphysics and Multiscale Models in Modeling Solidification of Steel Ingots and DC Casting of Aluminum

NASA Astrophysics Data System (ADS)

Combeau, Hervé; Založnik, Miha; Bedel, Marie

2016-08-01

Prediction of solidification defects, such as macrosegregation and inhomogeneous microstructures, constitutes a key issue for industry. The development of models of casting processes needs to account for several imbricated length scales and different physical phenomena. For example, the kinetics of the growth of microstructures needs to be coupled with the multiphase flow at the process scale. We introduce such a state-of-the-art model and outline its principles. We present the most recent applications of the model to casting of a heavy steel ingot and to direct chill casting of a large Al alloy sheet ingot. Their ability to help in the understanding of complex phenomena, such as the competition between nucleation and growth of grains in the presence of convection of the liquid and of grain motion is shown, and its predictive capabilities are discussed. Key issues for future developments and research are addressed.

TiC reinforced cast Cr steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dogan, O.N.; Hawk, J.A.; Schrems, K.K.

2006-06-01

A new class of materials, namely TiC-reinforced cast chromium (Cr) steels, was developed for applications requiring high abrasion resistance and good fracture toughness. The research approach was to modify the carbide structure of commercial AISI 440C steel for better fracture resistance while maintaining the already high abrasion resistance. The new alloys contained 12Cr, 2.5–4.5Ti, and 1–1.5C (wt.%) and were melted in a vacuum induction furnace. Their microstructure was composed primarily of a martensitic matrix with a dispersion of TiC precipitates. Modification of TiC morphology was accomplished through changing the cooling rate during solidification. Wear rates of the TiC-reinforced Cr steelsmore » were comparable to that of AISI 440C steel, but the impact resistance was much improved.« less

Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Use of Laser Engineered Net Shaping for Rapid Manufacturing of Dies with Protective Coatings and Improved Thermal Management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brevick, Jerald R.

2014-06-13

In the high pressure die casting process, molten metal is introduced into a die cavity at high pressure and velocity, enabling castings of thin wall section and complex geometry to be obtained. Traditional die materials have been hot work die steels, commonly H13. Manufacture of the dies involves machining the desired geometry from monolithic blocks of annealed tool steel, heat treating to desired hardness and toughness, and final machining, grinding and polishing. The die is fabricated with internal water cooling passages created by drilling. These materials and fabrication methods have been used for many years, however, there are limitations. Toolmore » steels have relatively low thermal conductivity, and as a result, it takes time to remove the heat from the tool steel via the drilled internal water cooling passages. Furthermore, the low thermal conductivity generates large thermal gradients at the die cavity surfaces, which ultimately leads to thermal fatigue cracking on the surfaces of the die steel. The high die surface temperatures also promote the metallurgical bonding of the aluminum casting alloy to the surface of the die steel (soldering). In terms of process efficiency, these tooling limitations reduce the number of die castings that can be made per unit time by increasing cycle time required for cooling, and increasing downtime and cost to replace tooling which has failed either by soldering or by thermal fatigue cracking (heat checking). The objective of this research was to evaluate the feasibility of designing, fabricating, and testing high pressure die casting tooling having properties equivalent to H13 on the surface in contact with molten casting alloy - for high temperature and high velocity molten metal erosion resistance – but with the ability to conduct heat rapidly to interior water cooling passages. A layered bimetallic tool design was selected, and the design evaluated for thermal and mechanical performance via finite element analysis. H13 was retained as the exterior layer of the tooling, while commercially pure copper was chosen for the interior structure of the tooling. The tooling was fabricated by traditional machining of the copper substrate, and H13 powder was deposited on the copper via the Laser Engineered Net Shape (LENSTM) process. The H13 deposition layer was then final machined by traditional methods. Two tooling components were designed and fabricated; a thermal fatigue test specimen, and a core for a commercial aluminum high pressure die casting tool. The bimetallic thermal fatigue specimen demonstrated promising performance during testing, and the test results were used to improve the design and LENS TM deposition methods for subsequent manufacture of the commercial core. Results of the thermal finite element analysis for the thermal fatigue test specimen indicate that it has the ability to lose heat to the internal water cooling passages, and to external spray cooling, significantly faster than a monolithic H13 thermal fatigue sample. The commercial core is currently in the final stages of fabrication, and will be evaluated in an actual production environment at Shiloh Die casting. In this research, the feasibility of designing and fabricating copper/H13 bimetallic die casting tooling via LENS TM processing, for the purpose of improving die casting process efficiency, is demonstrated.« less

Bladesmithing at South Dakota School of Mines and Technology

NASA Astrophysics Data System (ADS)

Moehring, Jack; Willman, Michael; Pulscher, Isaac; Rowe, Devin

2016-12-01

A Damascus-style layered blade was made by incorporating bloomery iron and crucible steel. A bloomery furnace was constructed and charged with Black Hills, SD bog iron ore, alloys, and hardwood charcoal. At sufficient temperature, the furnace was bottom-tapped to produce a low carbon iron bloom. A high-carbon crucible steel was made in a natural gas-fired furnace using commercial hematite pellets and coke. The steel was cast into sand molds. The two types of iron/steel were forged together using traditional blacksmithing techniques in a coke-fired forge. The forging process continued until the metal could be evenly worked, signifying the homogenization of the two metals. Once homogenized, the metal was shaped into a blade and subsequently ground into near-final shape, heat-treated, and finish-machined. The microstructure and mechanical properties of the blade were characterized using optical microscopy, hardness and tensile testing. The grain structure of the material varied widely and was not entirely homogenous at the welded layers, but the layers themselves were well-homogenized. The finished blade was compared to a common steel (1095) used for bladesmithing and was found to have similar hardness but significantly lower tensile strength.

Evolution of the mandibular mesh implant.

PubMed

Salyer, K E; Johns, D F; Holmes, R E; Layton, J G

1977-07-01

Between 1960 and 1972, the Dallas Veterans Administration Hospital Maxillofacial Research Laboratory developed and made over 150 cast-mesh implants. Successive designs were ovoid, circular, and double-lumened in cross section to improve implant strength, surface area for bioattachment, and adjustability. Sleeves, collars, and bows were employed in the assembly of these implants, with an acrylic condylar head attached when indicated. In 1972, our laboratory developed a mandibular mesh tray, cast in one piece on a single sprue, with preservation of the vertically adjustable ramus. Stainless steel replaced Vitallium because of its greater malleability. Essentially, a lost-wax technique is used to cast the mesh tray. The model of a mandibular segment is duplicated as a refractory model. Mesh wax, made in our own custom-made die, is adapted to the refractory model. The unit is then sprued and invested. The wax is fired our of the mold in a gas furnace. Casting is done by the transferral of molten stainless steel from the crucible to the mold by centrifugal force in an electro-induction casting machine. Other mesh implants that have been developed are made from wire mesh, Dacron mesh, cast Ticonium, and hydroformed titanium.

4. DETAIL OF CAST AND WROUGHT IRON RAILING WITH SUPPORTING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. DETAIL OF CAST AND WROUGHT IRON RAILING WITH SUPPORTING STRUCTURES AND STEEL BEAM, FROM THE NORTH BANK LOOKING SOUTHEAST AT THE WEST (UPSTREAM) SIDE - Railroad Avenue Bridge, Spanning Mispillion River on Church Street, Milford, Sussex County, DE

Features of Wear-Resistant Cast Iron Coating Formation During Plasma-Powder Surfacing

NASA Astrophysics Data System (ADS)

Vdovin, K. N.; Emelyushin, A. N.; Nefed'ev, S. P.

2017-09-01

The structure of coatings deposited on steel 45 by plasma-powder surfacing of white wear-resistant cast iron is studied. The effects of surfacing regime and additional production effects on the welding bath during surfacing produced by current modulation, accelerated cooling of the deposited beads by blowing with air, and accelerated cooling of the substrate with running water on the structure, are determined. A new composition is suggested for powder material for depositing wear-resistant and corrosion-resistant coatings on a carbon steel by the plasma-powder process.

Physical metallurgy of BATMAN II Ti-bearing martensitic steels

NASA Astrophysics Data System (ADS)

Pilloni, L.; Attura, F.; Calza-Bini, A.; De Santis, G.; Filacchioni, G.; Carosi, A.; Amato, S.

1998-10-01

Seven laboratory experimental casts of 7-9% Cr Ti-bearing martensitic steels were obtained via VIM process. Plates of 25 mm thickness were produced by hot rolling. On each cast CCT diagrams and critical temperatures were determined. Several austenitizing treatments were performed to study the grain size evolution. The effect of microstructure on impact properties were finally investigated. This paper discusses the role of chemical composition on microstructural and physical properties and shows the beneficial effect either of low-temperature austenitizing or double-austenitizing steps on impact properties.

Investigation of Acoustic Emission during Fracture Toughness Testing of Chevron-Notched Specimens.

DTIC Science & Technology

1984-03-01

chevron-notched specimlens was employed to investigate crack growth in four steels )rel)ared by electroslag-remelt casting. 15-5PH, AISI 4140 , D6AC, and...this investigation: 15-SPH, AISI 4140 , D6AC and AISI 440C. The composition of each steel is given in Table 1. Castings were prepared by electro- slag...well defined, it appears that the AISI 4140 (Figure 2b) and the D6AC (Figure 2c) failed primarily by cleavage also. The fracture illustrated in Figure

Using special additions to preparation of the moulding mixture for casting steel parts of drive wheel type

NASA Astrophysics Data System (ADS)

Josan, A.; Pinca Bretotean, C.

2015-06-01

The paper presents the possibility of using special additions to the execution of moulding mixtures for steel castings, drive wheel type. Critical analysis of moulding technology leads to the idea that most defects appear due to using improper moulding mixture. Using a improper moulding mixture leads to penetration of steel in moulding mixture, resulting in the formation of adherences, due to inadequate refractarity of the mould and core mixtures. Using only the unique mixture to the moulding leads to increasing consumption of new sand, respectively to the increase of price of piece. Acording to the dates registered in the industrial practice is necessary to use the special additions to obtain the moulding mixtures, carbonaceous materials respectively.

Investigation of the interfacial reactions between steel and aluminum coatings for hybrid casting

NASA Astrophysics Data System (ADS)

Bobzin, K.; Öte, M.; Wiesner, S.; Gerdt, L.

2018-06-01

Coating of AA7075 was applied by means of cold gas spraying on steel substrates of 22MnB5 and DC04 as an interlayer for high pressure die casting of aluminum/steel hybrid components. The morphology and growth kinetics of intermetallic compounds formed at the interface between coating and steel has been investigated. Furthermore, the effect of alloying elements on the formation of the intermetallic phases was analyzed. The coated samples were heat treated by means of induction heating at the temperature T = 550 °C with different dwell times in the range of 10 s < t < 5 min. The reaction layer growth was examined by means of scanning electron microscope (SEM) with energy dispersive spectroscopy (EDS). Additionally, the intermetallic compounds were characterized by means of nanoindentation. Intermetallic compounds of AlFe phases occurred as the major constituent in the reaction zone for different combinations of coating and substrates.

Irradiation Microstructure of Austenitic Steels and Cast Steels Irradiated in the BOR-60 Reactor at 320°C

NASA Astrophysics Data System (ADS)

Yang, Yong; Chen, Yiren; Huang, Yina; Allen, Todd; Rao, Appajosula

Reactor internal components are subjected to neutron irradiation in light water reactors, and with the aging of nuclear power plants around the world, irradiation-induced material degradations are of concern for reactor internals. Irradiation-induced defects resulting from displacement damage are critical for understanding degradation in structural materials. In the present work, microstructural changes due to irradiation in austenitic stainless steels and cast steels were characterized using transmission electron microscopy. The specimens were irradiated in the BOR-60 reactor, a fast breeder reactor, up to 40 dpa at 320°C. The dose rate was approximately 9.4x10-7 dpa/s. Void swelling and irradiation defects were analyzed for these specimens. A high density of faulted loops dominated the irradiated-altered microstructures. Along with previous TEM results, a dose dependence of the defect structure was established at 320°C.

Casting technology for ODS steels - the internal oxidation approach

NASA Astrophysics Data System (ADS)

Miran, S.; Franke, P.; Möslang, A.; Seifert, H. J.

2017-07-01

The formation of stainless ODS steel by internal oxidation of as-cast steel has been investigated. An alloy (Fe-16Cr-0.2Al-0.05Y, wt.%) was embedded in a (VO/V2O3) powder mixture serving as an oxygen activity buffer and heat treated at 1450 °C for 20 h. After this procedure no oxide scale was present on the surface of the sample but a zone of internal oxidation with a depth of about 2000 μm was formed in its interior. The precipitates within this zone consisted of two types of oxides. Discrete aluminium oxide particles with a size of a few micrometres were formed in outer regions of the specimen. Finer aluminium-yttrium oxides with a size of some hundred nanometres were mainly precipitated in inner regions of the sample. The results can be considered as a promising step towards an alternative production route for ODS steels.

Deducing material quality in cast and hot-forged steels by new bending test

NASA Astrophysics Data System (ADS)

Valberg, Henry; Langøy, Morten; Nedreberg, Mette; Helvig, Torgeir

2017-10-01

A special bend test has been developed and applied for the purpose of characterization and comparison of the material ductility in crankpin steel discs manufactured by casting, or casting subsequently followed by hot open-die forging (ODF) or closed-die forging (CDF). The bending test specimen consists of a small rectangular plate of material with a round hole cut out in the middle. The "eye-shape" specimens were cut out from various positions either near to the surface of, or from the interior of the discs. The test method revealed differences in ductility for the investigated materials, and for different depth positions inside the discs. The roughening of the specimen surface on the top-side of the specimen bend also varied dependent on the processing method for the material. Current results show that this test method is useful for evaluation of material quality in differently processed material. Experimental bend test results are presented for differently processed variants of the same material, i.e., crankpin discs either made by solely casting or casting subsequently followed by hot working either by ODF or CDF.

Evaluation of interlocking bond strength between structured 1.0338 steel sheets and high pressure die cast AlMg5Si2

NASA Astrophysics Data System (ADS)

Senge, S.; Brachmann, J.; Hirt, G.; Bührig-Polaczek, A.

2018-05-01

Multi-material components open up new possibilities for functional design. Such components combine beneficial physical properties of different materials in a single component as for instance chemical resistance, high strength or low density. The challenge is a reliable bond between both materials to enable a long term usage. This paper deals with a form closure connection to ensure a solid connection between steel strips and high pressure die cast aluminium. Two different sizes of channel structures with width ratios of 1.0 and 1.35 are produced on a steel sheet. An ensuing flat rolling pass is performed to create undercuts with a width of up to 50 µm, enabling an interlocking of the molten aluminium in the concluding casting process. For both rolling processes the resulting geometry is analysed depending on the thickness reduction. In a subsequent high pressure die casting process, aluminium is applied resulting in a complete form filling for the coarser structure. Comparing structures with and without undercuts, only structures suited with undercuts remain gap-free after solidification contraction. The finer structure could not be filled completely; nevertheless these structures result in shear strength of up to 45 MPa transversal to the channel-direction.

Elimination of Hot Tears in Steel Castings by Means of Solidification Pattern Optimization

NASA Astrophysics Data System (ADS)

Kotas, Petr; Tutum, Cem Celal; Thorborg, Jesper; Hattel, Jesper Henri

2012-06-01

A methodology of how to exploit the Niyama criterion for the elimination of various defects such as centerline porosity, macrosegregation, and hot tearing in steel castings is presented. The tendency of forming centerline porosity is governed by the temperature distribution close to the end of the solidification interval, specifically by thermal gradients and cooling rates. The physics behind macrosegregation and hot tears indicate that these two defects also are dependent heavily on thermal gradients and pressure drop in the mushy zone. The objective of this work is to show that by optimizing the solidification pattern, i.e., establishing directional and progressive solidification with the help of the Niyama criterion, macrosegregation and hot tearing issues can be both minimized or eliminated entirely. An original casting layout was simulated using a transient three-dimensional (3-D) thermal fluid model incorporated in a commercial simulation software package to determine potential flaws and inadequacies. Based on the initial casting process assessment, multiobjective optimization of the solidification pattern of the considered steel part followed. That is, the multiobjective optimization problem of choosing the proper riser and chill designs has been investigated using genetic algorithms while simultaneously considering their impact on centerline porosity, the macrosegregation pattern, and primarily on hot tear formation.

Ultrasonic Sound Field Mapping Through Coarse Grained Cast Austenitic Stainless Steel Components

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-08-01

The Pacific Northwest National Laboratory (PNNL) has been involved with nondestructive examination (NDE) of coarse-grained cast austenitic stainless steel (CASS) components for over 30 years. More recent work has focused on mapping the ultrasonic sound fields generated by low-frequency phased array probes that are typically used for the evaluation of CASS materials for flaw detection and characterization. The casting process results in the formation of large grained material microstructures that are nonhomogeneous and anisotropic. The propagation of ultrasonic energy for examination of these materials results in scattering, partitioning and redirection of these sound fields. The work reported here provides anmore » assessment of sound field formation in these materials and provides recommendations on ultrasonic inspection parameters for flaw detection in CASS components.« less

Substructure detail view of the castinplace concrete bents and steel, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

Substructure detail view of the cast-in-place concrete bents and steel, longitudinal "I" beams. - Marion Creek Bridge, Spanning Marion Creek at Milepoint 66.42 on North Santiam Highway (OR-22), Marion Forks, Linn County, OR

Simulation of prepackaged grout bleed under field conditions : [summary].

DOT National Transportation Integrated Search

2014-04-01

Post-tensioning (PT) is a method of compensating : for concretes weakness under tension by adding : steel. Tubes (ducts) are cast into concrete : components; after the concrete sets, high-strength steel cables (tendons or strand) are run : through...

46 CFR 56.50-60 - Systems containing oil.

Code of Federal Regulations, 2014 CFR

2014-10-01

... °F must be of seamless steel. (See § 56.50-65 of this part.) (k) Oil piping drains, strainers and... is of steel construction, all welded, and not concealed. (d) Piping subject to internal head pressure... installed on the outside of the oil tanks must be made of steel, ductile cast iron ASTM A 395 (incorporated...

46 CFR 56.50-60 - Systems containing oil.

Code of Federal Regulations, 2012 CFR

2012-10-01

... °F must be of seamless steel. (See § 56.50-65 of this part.) (k) Oil piping drains, strainers and... is of steel construction, all welded, and not concealed. (d) Piping subject to internal head pressure... installed on the outside of the oil tanks must be made of steel, ductile cast iron ASTM A 395 (incorporated...

46 CFR 56.50-60 - Systems containing oil.

Code of Federal Regulations, 2011 CFR

2011-10-01

... °F must be of seamless steel. (See § 56.50-65 of this part.) (k) Oil piping drains, strainers and... is of steel construction, all welded, and not concealed. (d) Piping subject to internal head pressure... installed on the outside of the oil tanks must be made of steel, ductile cast iron ASTM A 395 (incorporated...

46 CFR 56.50-60 - Systems containing oil.

Code of Federal Regulations, 2010 CFR

2010-10-01

... °F must be of seamless steel. (See § 56.50-65 of this part.) (k) Oil piping drains, strainers and... is of steel construction, all welded, and not concealed. (d) Piping subject to internal head pressure... installed on the outside of the oil tanks must be made of steel, ductile cast iron ASTM A 395 (incorporated...

46 CFR 56.50-60 - Systems containing oil.

Code of Federal Regulations, 2013 CFR

2013-10-01

... °F must be of seamless steel. (See § 56.50-65 of this part.) (k) Oil piping drains, strainers and... is of steel construction, all welded, and not concealed. (d) Piping subject to internal head pressure... installed on the outside of the oil tanks must be made of steel, ductile cast iron ASTM A 395 (incorporated...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

46 CFR 56.25-10 - Flange facings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (incorporated by reference; see 46 CFR 56.01-2). (b) When bolting class 150 standard steel flanges to flat face cast iron flanges, the steel flange must be furnished with a flat face, and bolting must be in accordance with § 56.25-20 of this part. Class 300 raised face steel flanges may be bolted to class 250...

Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

NASA Astrophysics Data System (ADS)

Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

Development and Implementation of the Casting of Rods Made of Refractory Cast Alloys

NASA Astrophysics Data System (ADS)

Kabanov, I. V.; Urin, S. L.; Ivanyuk, A. S.; Nesterov, A. N.; Bogdanov, S. V.

2017-12-01

The problems of the production of a so-called casting rod blank made of a refractory casting alloy in the vacuum induction furnaces of AO Metallurgical Plant Electrostal are considered. A unique technology of casting and subsequent treatment of as-cast rod blanks made of refractory alloys is developed, tested, and optimized. As a result of the developed and performed measures for the production of metal products in the Consarc furnace, the ingot-to-product yield increases by 15% as compared to metal casting in an ISV-1.0 furnace. As a result, we have widened the range of cast alloy grades and are going to cast metals for the manufacture of blanks of other sizes and ranges of alloy an steel grades.

Morse Brothers, Inc. Harrisburg plant : high-strength concrete : research study.

DOT National Transportation Integrated Search

1987-07-01

This report is the seventh in a series of research studies designed to determine the difference in strength of concrete cylinders cast in steel molds vs. cylinders cast in plastic molds. Prior to this report, six other research studies on the differe...

15. TAKING A CAST AT FURNACE NO. 1 HOT SLAG, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

15. TAKING A CAST AT FURNACE NO. 1 HOT SLAG, BY-PRODUCT IN SMELTING OF PIG IRON, CAN BE SEEN FLOWING INTO THE SLAG YARD. VIEW IS LOOKING SOUTH. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

Fracture Toughness of Z3CN20.09M Cast Stainless Steel with Long-Term Thermal Aging

NASA Astrophysics Data System (ADS)

Yu, Weiwei; Yu, Dunji; Gao, Hongbo; Xue, Fei; Chen, Xu

2017-09-01

Accelerated thermal aging tests were performed at 400 °C for nearly 18,000 h on Z3CN20.09M cast stainless steel which was used for primary coolant pipes of nuclear power plants. A series of Charpy impact tests were conducted on Z3CN20.09M after different long-term thermal aging time. The test results indicated that the Charpy impact energy of Z3CN20.09M cast stainless steel decreased rapidly at an early stage and then almost saturated after thermal aging of 10,000 h. Furthermore, J-resistance curves were measured for CT specimens of longitudinal and circumferential pipe orientations. It showed that there was no obvious difference in the fracture characteristics of Z3CN20.09M in different sampling directions. In addition, the observed stretch zone width (SZW) revealed that the value of initiation fracture toughness J SZW was significantly lower than that of fracture toughness J IC, indicating a low actual crack initiation energy due to long-term thermal aging.

Prediction of Contact Fatigue Life of Alloy Cast Steel Rolls Using Back-Propagation Neural Network

NASA Astrophysics Data System (ADS)

Jin, Huijin; Wu, Sujun; Peng, Yuncheng

2013-12-01

In this study, an artificial neural network (ANN) was employed to predict the contact fatigue life of alloy cast steel rolls (ACSRs) as a function of alloy composition, heat treatment parameters, and contact stress by utilizing the back-propagation algorithm. The ANN was trained and tested using experimental data and a very good performance of the neural network was achieved. The well-trained neural network was then adopted to predict the contact fatigue life of chromium alloyed cast steel rolls with different alloy compositions and heat treatment processes. The prediction results showed that the maximum value of contact fatigue life was obtained with quenching at 960 °C, tempering at 520 °C, and under the contact stress of 2355 MPa. The optimal alloy composition was C-0.54, Si-0.66, Mn-0.67, Cr-4.74, Mo-0.46, V-0.13, Ni-0.34, and Fe-balance (wt.%). Some explanations of the predicted results from the metallurgical viewpoints are given. A convenient and powerful method of optimizing alloy composition and heat treatment parameters of ACSRs has been developed.

Mechanical properties and eddy current testing of thermally aged Z3CN20.09M cast duplex stainless steel

NASA Astrophysics Data System (ADS)

Liu, Tonghua; Wang, Wei; Qiang, Wenjiang; Shu, Guogang

2018-04-01

To study the thermal aging embrittlement of Z3CN20.09M duplex stainless steel produced in China, accelerated thermal aging experiments were carried out at 380 °C up to 9000 h. Microhardness measurements, Charpy impact and eddy current tests were performed on aged samples to characterize their thermal aging embrittlement. The results showed that the signal amplitude of eddy current decreased with the increase in aging time. Two quantitative correlations of the eddy current signal amplitude with both the Charpy impact energy, and the Vickers microhardness of the ferrite phase are obtained. The study showed that eddy current testing could be used to non-destructively evaluate the thermal aging embrittlement of cast duplex stainless steels.

Evaluation of a Belt-Cast Austenitic Steel Alloy from Salzgitter Mannesmann Forschung: Effect of Hardness on the Ballistic Resistance against Two 0.30-cal. Projectile Types

DTIC Science & Technology

2017-08-01

obtained from Salzgitter Mannesmann Forschung, a German steel manufacturing concern. The steel samples were subjected to microstructural and quasi ... Experimental Procedures 4 4. Results and Discussion 7 4.1 Microstructural and Mechanical Properties 7 4.2 Ballistic Testing 14 5. Summary and Conclusions...austenitic steels. Reprinted with permission. ................................................................... 2 Fig. 2 Experimental setup. A

Optimization of Composition and Heat Treating of Die Steels for Extended Lifetime

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Schwam; John F. Wallace; Quanyou Zhou

2002-01-30

An ''average'' die casting die costs fifty thousand dollars. A die used in making die cast aluminum engine blocks can cost well over one million dollars. These costs provide a strong incentive for extension of die life. While vacuum quenched Premium Grade H13 dies have become the most widely used in the United States, tool makers and die casters are constantly searching for new steels and heat treating procedures to extend die life. This project was undertaken to investigate the effects of composition and heat treating on die life and optimize these parameters.

75 FR 3203 - Certain Oil Country Tubular Goods From the People's Republic of China: Amended Final Affirmative...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-20

... cross-section, including oil well casing and tubing, of iron (other than cast iron) or steel (both carbon and alloy), whether seamless or welded, regardless of end finish (e.g., whether or not plain end... December 14, 2009, petitioners United States Steel Corporation (``U.S. Steel'') and TMK IPSCO et al.\\1...

Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mburu, Sarah; Kolli, R. Prakash; Perea, Daniel E.

The microstructure and mechanical properties in unaged and thermally aged (at 280 °C, 320 °C, 360 °C, and 400 °C to 4300 h) CF–3 and CF–8 cast duplex stainless steels (CDSS) are investigated. The unaged CF–8 steel has Cr-rich M 23C 6 carbides located at the δ–ferrite/γ–austenite heterophase interfaces that were not observed in the CF–3 steel and this corresponds to a difference in mechanical properties. Both unaged steels exhibit incipient spinodal decomposition into Fe-rich α–domains and Cr-rich α’–domains. During aging, spinodal decomposition progresses and the mean wavelength (MW) and mean amplitude (MA) of the compositional fluctuations increase as amore » function of aging temperature. Additionally, G–phase precipitates form between the spinodal decomposition domains in CF–3 at 360 °C and 400 °C and in CF–8 at 400 °C. Finally, the microstructural evolution is correlated to changes in mechanical properties.« less

Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels

DOE PAGES

Mburu, Sarah; Kolli, R. Prakash; Perea, Daniel E.; ...

2017-03-06

The microstructure and mechanical properties in unaged and thermally aged (at 280 °C, 320 °C, 360 °C, and 400 °C to 4300 h) CF–3 and CF–8 cast duplex stainless steels (CDSS) are investigated. The unaged CF–8 steel has Cr-rich M 23C 6 carbides located at the δ–ferrite/γ–austenite heterophase interfaces that were not observed in the CF–3 steel and this corresponds to a difference in mechanical properties. Both unaged steels exhibit incipient spinodal decomposition into Fe-rich α–domains and Cr-rich α’–domains. During aging, spinodal decomposition progresses and the mean wavelength (MW) and mean amplitude (MA) of the compositional fluctuations increase as amore » function of aging temperature. Additionally, G–phase precipitates form between the spinodal decomposition domains in CF–3 at 360 °C and 400 °C and in CF–8 at 400 °C. Finally, the microstructural evolution is correlated to changes in mechanical properties.« less

Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mburu, Sarah; Kolli, R. Prakash; Perea, Daniel E.

The microstructure and mechanical properties in unaged and thermally aged (at 280 oC, 320 oC, 360 oC, and 400 oC to 4300 h) CF–3 and CF–8 cast duplex stainless steels (CDSS) are investigated. The unaged CF–8 steel has Cr-rich M23C6 carbides located at the δ–ferrite/γ– austenite heterophase interfaces that were not observed in the CF–3 steel and this corresponds to a difference in mechanical properties. Both unaged steels exhibit incipient spinodal decomposition into Fe-rich α–domains and Cr-rich α’–domains. During aging, spinodal decomposition progresses and the mean wavelength (MW) and mean amplitude (MA) of the compositional fluctuations increase as a functionmore » of aging temperature. Additionally, G–phase precipitates form between the spinodal decomposition domains in CF–3 at 360 oC and 400 oC and in CF–8 at 400 oC. The microstructural evolution is correlated to changes in mechanical properties.« less

75 FR 53301 - Notice of a Regional Project Waiver of Section 1605 (Buy American) of the American Recovery and...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-31

... blades are completely submerged. No stainless steel jackets that cover a cast iron housing shall be... shaft and hub grease chamber from the mixed media, running on a stainless steel exchangeable wear...

Evaluation of catch basin grates : final report.

DOT National Transportation Integrated Search

1972-10-01

The Louisiana Department of Highways has adopted new designs for the Standard Plans for the RCB 22X catch basin to replace the old standard cast iron grate with either a welded bar steel grate or an alternate riveted steel reticuline grate. This revi...

Thermophysical property sensitivity effects in steel solidification

NASA Technical Reports Server (NTRS)

Overfelt, Tony

1993-01-01

The simulation of advanced solidification processes via digital computer techniques has gained widespread acceptance during the last decade or so. Models today can predict transient temperature fields, fluid flow fields, important microstructural parameters, and potential defects in castings. However, the lack of accurate thermophysical property data on important industrial alloys threatens to limit the ability of manufacturers to fully capitalize on the technology's benefits. A study of the sensitivity of one such numerical model of a steel plate casting to imposed variations in the data utilized for the thermal conductivity, specific heat, density, and heat of fusion is described. The sensitivity of the data's variability is characterized by its effects on the net solidification time of various points along the centerline of the plate casting. Recommendations for property measurements are given and the implications of data uncertainty for modelers are discussed.

ICAM Manufacturing Cost/Design Guide. Volume 3. Airframes. User’s Manual.

DTIC Science & Technology

1983-01-01

COST-DRIVER EFFECT 17 -413H Investment Cast 17 - 4PH Investment Cast 2 2 - U) *oo 0±0.01 ±0.02 ±0.03 0±0.01 ±0.02 ±0.03 356iA356 Aluminum 356/A356...B +20% CAST B +50% 17 - 4PH CRES DORC BASE INVESTMENT D OR C WITH 10% B +20% CAST D OR C WITH 50% B +30% B +60% NOTE: X-Ray Grade A Is an Impractical...per QQ-A-601 (sand castings) - 357 per MIL-A-21180 (sand castings) a Steel - 17 - 4PH CRES per AMS-5342, 5343, and 5344 or * company equivalent

20. TAKING A CAST AT BLAST FURNACE NO. 1. WORKERS, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

20. TAKING A CAST AT BLAST FURNACE NO. 1. WORKERS, LIKE THE ONE STANDING ON THE BRIDGE ABOVE THE 'BOTTLE' INTO WHICH THE HOT IRON FLOWS, ARE PROTECTED BY HEAVY FIREPROOF GARMENTS. - Corrigan, McKinney Steel Company, 3100 East Forty-fifth Street, Cleveland, Cuyahoga County, OH

2. View of pier #3, West approach, Detroit Superior High ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. View of pier #3, West approach, Detroit Superior High Level bridge (1914-1917). Pier #3 and #4 support the steel rive span. They are 116 feet by 80 feet at the base and rest on stiff blue clay 45 feet below the surface of the river. Cast-steel bolsters of the three-hinge steel arch are anchored by structural steel grillage to the masory piers. - Detroit Superior High Level Bridge, Cleveland, Cuyahoga County, OH

A new experimental apparatus for emissivity measurements of steel and the application of multi-wavelength thermometry to continuous casting billets

NASA Astrophysics Data System (ADS)

Wang, Peng; Hu, Zhenwei; Xie, Zhi; Yan, Ming

2018-05-01

An experimental apparatus has been designed for measuring the emissivity of a steel surface in both vacuum and oxidation atmosphere. The sample is heated with the method of electromagnetic induction in order to ensure the temperature uniformity. The radiance emitted from a sample is measured using a fiber-optic Fourier transform infrared spectrometer. Using this unique apparatus, we investigated the spectral (2-6 μm) and directional (0°-86°) emissivity of stainless steel 304 with different degrees of surface oxidation at temperatures ranging from 800 to 1100 °C. The experimental results show that the emissivity increases slightly with increasing temperature, which accords with the Hagen-Rubens relation. The emissivity increases rapidly at the initial stage of oxidation, but gradually reaches to a constant value after 20 min. In addition, the directional emissivity has a maximum value at the measuring angle of about 75°. The maximum uncertainty of emissivity is only 3.0% over all the measuring ranges, indicating that this experimental apparatus has a high reliability. In order to measure the surface temperature of casting billets based on multi-wavelength thermometry, the bivariate emissivity function with the two variables, wavelength and temperature, is determined. Temperature measurement results based on our technique are compared with those from common dual-wavelength radiation thermometry. Our approach reduces the measured temperature fluctuation from ±20.7 °C to ±2.8 °C and reflects the temperature variation with the changes of production parameters in real time.

Europe Report, Science and Technology

DTIC Science & Technology

1986-12-01

i) the absence of secondary oxidation of the liquid steel to the advantagf of the inclusional state; (ii) the possibility of more easily casting...processes, inclusions cannot become separated 11 from the bar, thus rising to the surface, which is why the inclusional state of the steel, that

Formation Mechanism of Oxide-Sulfide Complex Inclusions in High-Sulfur-Containing Steel Melts

NASA Astrophysics Data System (ADS)

Shin, Jae Hong; Park, Joo Hyun

2018-02-01

The [S] content in resulfurized steel is controlled in the range of 200 to 800 ppm to ensure good machinability and workability. It is well known that "MgAl2O4(spinel)+CaS" complex inclusions are formed in molten steel during the ladle refining process, and these cause nozzle clogging during continuous casting. Thus, in the present study, the "Refractory-Slag-Metal-Inclusions (ReSMI)" multiphase reaction model was employed in conjunction with experiments to investigate the influence of slag composition and [S] content in the steel on the formation of oxide-sulfide complex inclusions. The critical [S] and [Al] contents necessary for the precipitation of CaS in the CaO-Al2O3-MgO-SiO2 (CAMS) oxide inclusions were predicted from the composition of the liquid inclusions, as observed by scanning electron microscopy-electron dispersive spectrometry (SEM-EDS) and calculated using the ReSMI multiphase reaction model. The critical [S] content increases with increasing content of SiO2 in the slag at a given [Al] content. Formation mechanisms for spinel+CaS and spinel+MnS complex inclusions were also proposed.

COST AND PERFORMANCE REPORT: INNOVATIVE ACOUSTIC SENSOR TECHNOLOGIES FOR LEAK DETECTION IN CHALLENGING PIPE TYPES

DTIC Science & Technology

2016-12-30

Operational Variable LeakFinderRT Equipment Logistics Portable Case Pipe Material Pit Cast Iron, Spun Cast Iron, Steel , Ductile Iron, Asbestos Cement ...AND ACRONYMS AC asbestos cement AMI advanced metering infrastructure AWWA American Water Works Association CI cast iron DI ductile iron DoD...assessing their ability to detect and accurately locate leaks in challenging pipe types such as polyvinyl chloride (PVC), asbestos cement (AC), and

Increasing the reliability and quality of important cast products made of chemically active metals and alloys

NASA Astrophysics Data System (ADS)

Varfolomeev, M. S.; Moiseev, V. S.; Shcherbakova, G. I.

2017-01-01

A technology is developed to produce highly thermoresistant ceramic monoxide corundum molds using investment casting and an aluminum-organic binder. This technology is a promising trend in creating ceramic molds for precision complex-shape casting of important ingots made of high-alloy steels, high-temperature and titanium alloys, and refractory metals. The use of the casting molds that have a high thermal and chemical resistance to chemically active metals and alloys under high-temperature casting minimizes the physicochemical interaction and substantially decreases the depth of the hard-to-remove metal oxide layer on important products, which increases their service properties.

Application of stochastic approach based on Monte Carlo (MC) simulation for life cycle inventory (LCI) to the steel process chain: case study.

PubMed

Bieda, Bogusław

2014-05-15

The purpose of the paper is to present the results of application of stochastic approach based on Monte Carlo (MC) simulation for life cycle inventory (LCI) data of Mittal Steel Poland (MSP) complex in Kraków, Poland. In order to assess the uncertainty, the software CrystalBall® (CB), which is associated with Microsoft® Excel spreadsheet model, is used. The framework of the study was originally carried out for 2005. The total production of steel, coke, pig iron, sinter, slabs from continuous steel casting (CSC), sheets from hot rolling mill (HRM) and blast furnace gas, collected in 2005 from MSP was analyzed and used for MC simulation of the LCI model. In order to describe random nature of all main products used in this study, normal distribution has been applied. The results of the simulation (10,000 trials) performed with the use of CB consist of frequency charts and statistical reports. The results of this study can be used as the first step in performing a full LCA analysis in the steel industry. Further, it is concluded that the stochastic approach is a powerful method for quantifying parameter uncertainty in LCA/LCI studies and it can be applied to any steel industry. The results obtained from this study can help practitioners and decision-makers in the steel production management. Copyright © 2013 Elsevier B.V. All rights reserved.

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part II. Isothermal aging kinetics

NASA Astrophysics Data System (ADS)

Robino, C. V.; Cieslak, M. J.; Hochanadel, P. W.; Edwards, G. R.

1994-04-01

The hardening response of investment cast PH 13-8 Mo stainless steel has been evaluated by hardness measurements following aging in the temperature range normally specified for this alloy (510 °C to 593 °C). A new relationship between fraction transformed and hardness was developed, and analysis of the data in terms of the kinetics of precipitation, in a manner similar to that frequently applied to other precipitation-hardenable martensitic steels, yielded low time exponents and a low value for the apparent activation energy. The values of the time exponents were 0.49, 0.37, 0.56, and 0.53 at 510 °C, 538 °C, 566 °C, and 593 °C, respectively, and that for the apparent activation energy was 139 kJ/mole. As has been proposed for other maraging type steels, these estimates suggest that Β-NiAl precipitates along or near dislocations and that growth of the precipitates is dominated by dislocation pipe diffusion. However, these predictions were neither supported nor refuted by transmission electron microscopy (TEM) because of difficulties in imaging the Β-NiAl precipitates at the aging times and temperatures used. Further, analysis of the data using the formalism of Wert and Zener for the growth of precipitates with interfering diffusion fields indicated that the estimates of fraction transformed from hardness data are not fully appropriate for maraging type steels. Consideration of the nature of the Avrami analysis and the electron microscopy results suggests that other phenomena, including dislocation recovery and reversion of martensite to austenite, occur at rates sufficient to convolute the Avrami analysis. It is further suggested that these results cast doubt on the fundamental implications of previous analyses of precipitation kinetics in age-hardening martensitic steels. Although the Avrami analysis was found not to provide a tenable description of the precipitation kinetics, it does provide a reasonable methodology for portrayal of the hardening response of PH 13-8 Mo stainless steel.

Role of alloy additions on strengthening in 17-4 PH stainless steel

NASA Astrophysics Data System (ADS)

Murthy, Arpana Sudershan

Alloy modifications by addition of niobium (Nb), vanadium (V), nitrogen (N) and cobalt (Co) to cast 17-4 PH steel were investigated to determine the effect on mechanical properties. Additions of Nb, V, and N increased the yield strength from 1120 MPa to 1310 MPa while decreased the room temperature charpy V notch (CVN) toughness from 20 J to four Joules. The addition of Co to cast 17-4 PH steel enhanced the yield strength and CVN toughness from 1140 MPa to 1290 MPa and from 3.7 J to 5.5 J, respectively. In the base 17-4 PH steel, an increase in block width from 2.27 ± 0.10 μm in the solution treated condition to 3.06 ± 0.17 μm upon aging at 755 K was measured using orientation image microscopy. Cobalt inhibited recrystallization and block boundary migration during aging resulting in a finer martensitic block structure. The influence of Co on copper (Cu) precipitation in steels was studied using atom probe tomography. A narrower precipitate size distribution was observed in the steels with Co addition. The concentration profile across the matrix / precipitate interface indicated rejection of Co atoms from the copper precipitates. This behavior was observed to be energetically favorable using first principle calculations. The activation energies for Cu precipitation increased from 205 kJ/ mol in the non-cobalt containing alloy, to 243 kJ/ mol, and 272 kJ/ mol in alloys with 3 wt. %Co, and 7 wt. % Co, respectively. The role of Co on Cu precipitation in cast 17-4 PH steel is proposed as follows: (i) Co is rejected out of the Cu precipitate and sets up a barrier to the growth of the Cu precipitate; (ii) results in Cu precipitates of smaller size and narrower distribution; (iii) the coarsening of Cu precipitates is inhibited; and (iv) the activation energy for Cu precipitation increases.

Cast heat-resistant austenitic steel with improved temperature creep properties and balanced alloying element additions and methodology for development of the same

DOEpatents

Pankiw, Roman I; Muralidharan, Govindrarajan; Sikka, Vinod Kumar; Maziasz, Philip J

2012-11-27

The present invention addresses the need for new austenitic steel compositions with higher creep strength and higher upper temperatures. The new austenitic steel compositions retain desirable phases, such as austenite, M.sub.23C.sub.6, and MC in its microstructure to higher temperatures. The present invention also discloses a methodology for the development of new austenitic steel compositions with higher creep strength and higher upper temperatures.

The role of heat transfer in strip casting

NASA Astrophysics Data System (ADS)

Misra, Paretosh

The last few years have witnessed rapid developments in the area of strip casting of steel. It involves smaller capital and operating cost, lower greenhouse gas emissions, and an opportunity to create newer products due to a faster solidification rate that leads to a different solidification structure. Thus, ample reasons for interest in the technology exist. At the same time, it needs to be determined if the properties of a strip cast product can match those of a conventional product and if it is possible to produce steel strip at high production rates. The first objective of this work was to characterize the quality, structure, and properties of strip cast material of different chemistries and cast at different machines, to identify the critical operating conditions that would result in the best properties. Determination of the possible range of properties was also aimed, given that the structure of the material is different from the traditional material. The second objective was to investigate ways to increase the rate of heat transfer in strip casting, as that will also enhance the productivity of a strip caster. It was also envisaged to see what effect a high rate of heat transfer will have on the properties of the strip cast material. Results from the strip cast material characterization that was carried out to achieve the first objective indicated that an effective control of heat transfer is very important to get the best properties. Samples that showed best properties had a uniform solidification structure consisting of columnar grains running from the edge of a strip to the centerline, indicating a good control of heat transfer, and their dendrite spacings pointed towards a relatively faster rate of cooling between the rolls. These findings indicated that heat transfer is a core issue in strip casting. The mechanism of increase in the rate of heat transfer in strip casting due to the presence of liquid oxide films at the metal-mold interface was examined. It was discovered that these films originate from the metal itself. A high degree of interdendritic supersaturation can lead to the formation of low melting point oxide phases by the deoxidizing agents in the steel. As the temperature lowers further the film may get ejected out of the metal due to the non-wetting of the metal by the oxide phase. If enough oxide film can be generated then this can result in an almost two-fold increase in the rate of heat transfer during initial solidification---the first 20 milliseconds. The results indicate that if a proper control of these films is ensured then it provides an attractive alternative to increasing the roll diameter as a mechanism of increasing the rate of production of a strip caster. This mechanism will work even with smaller diameter rolls, in fact, perhaps better in that case due to a smaller interface area over which uniformity of heat transfer has to be ensured, thus leveraging its full advantages. If successfully implemented at a plant, this technique can help the strip casting machines to increase their productivity and emerge as a competitive technology to produce steel strip.

Effects of N/C Ratio on Solidification Behaviors of Novel Nb-Bearing Austenitic Heat-Resistant Cast Steels for Exhaust Components of Gasoline Engines

NASA Astrophysics Data System (ADS)

Zhang, Yinhui; Li, Mei; Godlewski, Larry A.; Zindel, Jacob W.; Feng, Qiang

2017-03-01

In order to comply with more stringent environmental and fuel consumption regulations, novel Nb-bearing austenitic heat-resistant cast steels that withstand exhaust temperatures as high as 1,323 K (1,050 °C) is urgently demanded from automotive industries. In the current research, the solidification behavior of these alloys with variations of N/C ratio is investigated. Directional solidification methods were carried out to examine the microstructural development in mushy zones. Computational thermodynamic calculations under partial equilibrium conditions were performed to predict the solidification sequence of different phases. Microstructural characterization of the mushy zones indicates that N/C ratio significantly influenced the stability of γ-austenite and the precipitation temperature of NbC/Nb(C,N), thereby altering the solidification path, as well as the morphology and distribution of NbC/Nb(C,N) and γ-ferrite. The solidification sequence of different phases predicted by thermodynamic software agreed well with the experimental results, except the specific precipitation temperatures. The generated data and fundamental understanding will be helpful for the application of computational thermodynamic methods to predict the as-cast microstructure of Nb-bearing austenitic heat-resistant steels.

The Kinetics of Phase Transformations During Tempering in Laser Melted High Chromium Cast Steel

NASA Astrophysics Data System (ADS)

Li, M. Y.; Wang, Y.; Han, B.

2012-06-01

The precipitation of secondary carbides in the laser melted high chromium cast steels during tempering at 300-650 °C for 2 h in air furnace was characterized and the present phases was identified, by using transmission electron microscopy. Laser melted high chromium cast steel consists of austenitic dendrites and interdendritic M23C6 carbides. The austenite has such a strong tempering stability that it remains unchanged at temperature below 400 °C and the secondary hardening phenomenon starts from 450 °C to the maximum value of 672 HV at 560 °C. After tempering at 450 °C fine M23C6 carbides precipitate from the supersaturated austenite preferentially. In addition, the dislocation lines and slip bands still exist inside the austenite. While tempering at temperature below 560 °C, the secondary hardening simultaneously results from the martensite phase transformation and the precipitation of carbides as well as dislocation strengthening within a refined microstructure. Moreover, the formation of the ferrite matrix and large quality of coarse lamellar M3C carbides when the samples were tempered at 650 °C contributes to the decrease of hardness.

Porosity Defect Remodeling and Tensile Analysis of Cast Steel

PubMed Central

Sun, Linfeng; Liao, Ridong; Lu, Wei; Fu, Sibo

2016-01-01

Tensile properties on ASTM A216 WCB cast steel with centerline porosity defect were studied with radiographic mapping and finite element remodeling technique. Non-linear elastic and plastic behaviors dependent on porosity were mathematically described by relevant equation sets. According to the ASTM E8 tensile test standard, matrix and defect specimens were machined into two categories by two types of height. After applying radiographic inspection, defect morphologies were mapped to the mid-sections of the finite element models and the porosity fraction fields had been generated with interpolation method. ABAQUS input parameters were confirmed by trial simulations to the matrix specimen and comparison with experimental outcomes. Fine agreements of the result curves between simulations and experiments could be observed, and predicted positions of the tensile fracture were found to be in accordance with the tests. Chord modulus was used to obtain the equivalent elastic stiffness because of the non-linear features. The results showed that elongation was the most influenced term to the defect cast steel, compared with elastic stiffness and yield stress. Additional visual explanations on the tensile fracture caused by void propagation were also given by the result contours at different mechanical stages, including distributions of Mises stress and plastic strain. PMID:28787919

VIEW FROM THE SOUTH OF THE #2 BLAST FURNACE AND ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

VIEW FROM THE SOUTH OF THE #2 BLAST FURNACE AND CASTING SEED ON THE LEFT, THE #1 BLAST FURNACE AND CASTING SHED ON THE RIGHT, AND THE STOVES, BOILERS, AND AUXILIARY EQUIPMENT IN THE CENTER. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

46 CFR 56.60-1 - Acceptable materials and specifications (replaces 123 and Table 126.1 in ASME B31.1).

Code of Federal Regulations, 2014 CFR

2014-10-01

... standards ASME standards Notes Pipe, seamless: A 106 Carbon steel ASME B31.1 A 335 Ferritic alloys ASME B31.1 A 376 Austenitic alloys ASME B31.1 (1). Pipe, seamless and welded: A 53 Types S, F, and E steel... cast: (None applicable) (1 9) Tube, seamless: A 179 Carbon steel heat exchanger and condenser tubes...

46 CFR 56.60-1 - Acceptable materials and specifications (replaces 123 and Table 126.1 in ASME B31.1).

Code of Federal Regulations, 2013 CFR

2013-10-01

... standards ASME standards Notes Pipe, seamless: A 106 Carbon steel ASME B31.1 A 335 Ferritic alloys ASME B31.1 A 376 Austenitic alloys ASME B31.1 (1). Pipe, seamless and welded: A 53 Types S, F, and E steel... cast: (None applicable) (1 9) Tube, seamless: A 179 Carbon steel heat exchanger and condenser tubes...

46 CFR 56.60-1 - Acceptable materials and specifications (replaces 123 and Table 126.1 in ASME B31.1).

Code of Federal Regulations, 2012 CFR

2012-10-01

... standards ASME standards Notes Pipe, seamless: A 106 Carbon steel ASME B31.1 A 335 Ferritic alloys ASME B31.1 A 376 Austenitic alloys ASME B31.1 (1). Pipe, seamless and welded: A 53 Types S, F, and E steel... cast: (None applicable) (1,9) Tube, seamless: A 179 Carbon steel heat exchanger and condenser tubes...

Three-Dimensional Flow Behavior Inside the Submerged Entry Nozzle

NASA Astrophysics Data System (ADS)

Real-Ramirez, Cesar Augusto; Carvajal-Mariscal, Ignacio; Sanchez-Silva, Florencio; Cervantes-de-la-Torre, Francisco; Diaz-Montes, Jesus; Gonzalez-Trejo, Jesus

2018-05-01

According to various authors, the surface quality of steel depends on the dynamic conditions that occur within the continuous casting mold's upper region. The meniscus, found in that upper region, is where the solidification process begins. The liquid steel is distributed into the mold through a submerged entry nozzle (SEN). In this paper, the dynamic behavior inside the SEN is analyzed by means of physical experiments and numerical simulations. The particle imaging velocimetry technique was used to obtain the vector field in different planes and three-dimensional flow patterns inside the SEN volume. Moreover, large eddy simulation was performed, and the turbulence model results were used to understand the nonlinear flow pattern inside the SEN. Using scaled physical and numerical models, quasi-periodic behavior was observed due to the interaction of two three-dimensional vortices that move inside the SEN lower region located between the exit ports of the nozzle.

Medium-Alloy Manganese-Rich Transformation-Induced Plasticity Steels

NASA Astrophysics Data System (ADS)

Suh, Dong Woo; Ryu, Joo Hyun; Joo, Min Sung; Yang, Hong Seok; Lee, Kyooyoung; Bhadeshia, H. K. D. H.

2013-01-01

The manganese concentration of steels which rely on transformation-induced plasticity is generally less than 2 wt pct. Recent work has highlighted the potential for strong and ductile alloys containing some 6 wt pct of manganese, but with aluminum additions in order to permit heat treatments which are amenable to rapid production. However, large concentrations of aluminum also cause difficulties during continuous casting. Alloy design calculations have been carried out in an effort to balance these conflicting requirements, while maintaining the amount of retained austenite and transformation kinetics. The results indicate that it is possible by adjusting the carbon and manganese concentrations to reduce the aluminum concentration, without compromising the mechanical properties or transformation kinetics. The deformation-induced transformation of retained austenite is explained quantitatively, for a range of alloys, in terms of a driving force which takes into account the very fine state of the retained austenite.

Development of TRIP-Aided Lean Duplex Stainless Steel by Twin-Roll Strip Casting and Its Deformation Mechanism

NASA Astrophysics Data System (ADS)

Zhao, Yan; Zhang, Weina; Liu, Xin; Liu, Zhenyu; Wang, Guodong

2016-12-01

In the present work, twin-roll strip casting was carried out to fabricate thin strip of a Mn-N alloyed lean duplex stainless steel with the composition of Fe-19Cr-6Mn-0.4N, in which internal pore defects had been effectively avoided as compared to conventional cast ingots. The solidification structure observed by optical microscope indicated that fine Widmannstatten structure and coarse-equiaxed crystals had been formed in the surface and center, respectively, with no columnar crystal structures through the surface to center of the cast strip. By applying hot rolling and cold rolling, thin sheets with the thickness of 0.5 mm were fabricated from the cast strips, and no edge cracks were formed during the rolling processes. With an annealing treatment at 1323 K (1050 °C) for 5 minutes after cold rolling, the volume fractions of ferrite and austenite were measured to be approximately equal, and the distribution of alloying elements in the strip was further homogenized. The cold-rolled and annealed sheet exhibited an excellent combination of strength and ductility, with the ultimate tensile strength and elongation having been measured to be 1000 MPa and 65 pct, respectively. The microstructural evolution during deformation was investigated by XRD, EBSD, and TEM, indicating that ferrite and austenite had different deformation mechanisms. The deformation of ferrite phase was dominated by dislocation slipping, and the deformation of austenite phase was mainly controlled by martensitic transformation in the sequence of γ→ ɛ-martensite→ α'-martensite, leading to the improvement of strength and plasticity by the so-called transformation-induced plasticity (TRIP) effect. By contrast, lean duplex stainless steels of Fe-21Cr-6Mn-0.5N and Fe-23Cr-7Mn-0.6N fabricated by twin-roll strip casting did not show TRIP effects and exhibited lower strength and elongation as compared to Fe-19Cr-6Mn-0.4N.

High Integrity Castings: Proceedings of the Conference on Advances in High Integrity Castings Held in Conjunction with the 1988 World Materials Congress, Chicago, Illinois, USA, 24-30 September 1988

DTIC Science & Technology

1988-01-01

above design requirements. The The first cast parts used in this higher strength standard chemistry parts application were of the Extra Low...present work was to study the use of beta THE HIGH COST OF TITANIUM alloys can limit their titanium alloys in the cast form. Beta or use to applications ...refractory as was is intended to achieve a pouring stream su- used with the nozzles for steel applications . perior to conventional nozzle designs , and this

Predicting Pattern Tooling and Casting Dimensions for Investment Casting, Phase III

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabau, Adrian S

2008-04-01

Efforts during Phase III focused mainly on the shell-alloy systems. A high melting point alloy, 17-4PH stainless steel, was considered. The experimental part of the program was conducted at ORNL and commercial foundries, where wax patterns were injected, molds were invested, and alloys were poured. Shell molds made of fused-silica and alumino-silicates were considered. A literature review was conducted on thermophysical and thermomechanical properties alumino-silicates. Material property data, which were not available from material suppliers, was obtained. For all the properties of 17-4PH stainless steel, the experimental data available in the literature did not cover the entire temperature range necessarymore » for process simulation. Thus, some material properties were evaluated using ProCAST, based on CompuTherm database. A comparison between the predicted material property data and measured property data was made. It was found that most material properties were accurately predicted only over several temperature ranges. No experimental data for plastic modulus were found. Thus, several assumptions were made and ProCAST recommendations were followed in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted during heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed different evolution on heating and cooling. Numerical simulations were performed using ProCAST for the investment casting of 17-4PH stainless steel parts in fused silica molds using the thermal expansion obtained on heating and another one with thermal expansion obtained on cooling. Since the fused silica shells had the lowest thermal expansion properties in the industry, the dewaxing phase, including the coupling between wax-shell systems, was neglected. The shell mold was considered to be a pure elastic material. The alloy dimensions were obtained from numerical simulations. For 17-4PH stainless steel parts, the alloy shrinkage factors were over-predicted, as compared with experimental data. Additional R&D focus was placed on obtaining material property data for filled waxes, waxes that are common in the industry. For the first time in the investment casting industry, the thermo-mechanical properties of unfilled and filled waxes were measured. Test specimens of three waxes were injected at commercial foundries. Rheometry measurement of filled waxes was conducted at ORNL. The analysis of the rheometry data to obtain viscoelastic properties was not completed due to the reduction in the budget of the project (approximately 50% funds were received).« less

On the Alternate Stirring Mode of F-EMS for Bloom Continuous Castings

NASA Astrophysics Data System (ADS)

Sun, Haibo; Li, Liejun; Ye, Dexin; Wu, Xuexing

2018-05-01

Local solute transportation behaviors under different alternate stirring parameters of final electromagnetic stirring (F-EMS) and their influences on the internal quality of the as-cast bloom are compared and evaluated based on a developed coupled model of electromagnetism, heat, and solute transport. To this end, plant trials were conducted in Shaoguan Steel, China. Under the action of F-EMS, a negative segregation band in an ellipse shape is observed at the central area of strand cross section, where the minimum carbon segregation degree is decreased from 0.98 to 0.84 as the stirring duration increases from 15 to 35 seconds in the alternate stirring mode, while it is reduced to 0.805 in the continuous stirring mode. The white band and shrinkage cavity are simultaneously observed at strand center under the conditions of continuous stirring mode, and alternate stirring mode with a stirring period of 35 seconds because of the local over-sustaining melt rotation. In contrast, the V-shape porosity belt width and strand center segregation fluctuation range increase from 60 to 90 mm and from 0.12 to 0.30, respectively, as the stirring duration is reduced from 25 to 15 seconds in the alternate stirring mode because of the poor mixing of the local melt at the strand center.

Stainless steel porous substrates produced by tape casting

NASA Astrophysics Data System (ADS)

Mercadelli, Elisa; Gondolini, Angela; Pinasco, Paola; Sanson, Alessandra

2017-01-01

In this work the technological issues related to the production of tape cast large-area porous stainless steel supports for Solid Oxide Fuel Cells (SOFC) applications were carefully investigated. The slurry formulation was optimized in terms of amount and nature of the organic components needed: rice starch and polymethyl metacrylate were found to be, respectively, the most suitable pore former and binder because easily eliminated during the thermal treatment in reducing atmosphere. The compatibility of the binder system chosen with the most widely used solvents for screen printing inks was also evaluated. Finally the influence of the sintering temperature and of the refractory supports to be used during the thermal treatments onto the production of porous stainless steel supports was discussed. The whole process optimization allows to produce flat, crack-free metallic substrate 900-1000 μm thick, dimensions up to 5×5 cm and with a tailored porosity of 40% suitable for SOFCs application.

A novel ultra-low carbon grain oriented silicon steel produced by twin-roll strip casting

NASA Astrophysics Data System (ADS)

Wang, Yang; Zhang, Yuan-Xiang; Lu, Xiang; Fang, Feng; Xu, Yun-Bo; Cao, Guang-Ming; Li, Cheng-Gang; Misra, R. D. K.; Wang, Guo-Dong

2016-12-01

A novel ultra-low carbon grain oriented silicon steel was successfully produced by strip casting and two-stage cold rolling method. The microstructure, texture and precipitate evolution under different first cold rolling reduction were investigated. It was shown that the as-cast strip was mainly composed of equiaxed grains and characterized by very weak Goss texture ({110}<001>) and λ-fiber (<001>//ND). The coarse sulfides of size 100 nm were precipitated at grain boundaries during strip casting, while nitrides remained in solution in the as-cast strip and the fine AlN particles of size 20-50 nm, which were used as grain growth inhibitors, were formed in intermediate annealed sheet after first cold rolling. In addition, the suitable Goss nuclei for secondary recrystallization were also formed during intermediate annealing, which is totally different from the conventional process that the Goss nuclei originated in the subsurface layer of the hot rolled sheet. Furthermore, the number of AlN inhibitors and the intensity of desirable Goss texture increased with increasing first cold rolling reduction. After secondary recrystallization annealing, very large grains of size 10-40 mm were formed and the final magnetic induction, B8, was as high as 1.9 T.

Thermophysical and Electronic Properties of Foreign Stainless Steels, A Comprehensive Survey of the World Literature,

DTIC Science & Technology

1981-11-01

included in its companion volume on nonstainless alloy steels carbon steels and cast irons. The TEPIAC retrieval system is based on assigning a seven...LOEFFILIENTS OF STRTUCTURAL M;.TE.)IALS AT LOW A. T,-E Tt-i!1AL 0,)NCuCfIVITY AND ITHE THERIIAL T ImA-FRi.Tu’ES. 11,fC’.4T OF IROI. AND STEELS It, THE Hlf...PROPERTIES OF FOREIGN STAINLESS STEELS A Comprehensive Survey of the World Literature P.D. DESAI CINDAS REPORT 61 November 1981 DTICS ELECTE Prepared by 0U

Solidification Based Grain Refinement in Steels

DTIC Science & Technology

2011-09-27

project (Tasks 7-9). An industrial trial on an investment casting was done using rare earth silicide additions in a furnace prior to pouring (Task 7...an investment casting was done using rare earth silicide additions in a furnace prior to pounng (la.sk 7). Some of the test parts had a finer...poured at the end of a six casting batch. One test tree with no RE addition was poured. Before the second test tree was poured, sufficient RE silicide was

Effective Process Design for the Production of HIC-Resistant Linepipe Steels

NASA Astrophysics Data System (ADS)

Nieto, J.; Elías, T.; López, G.; Campos, G.; López, F.; Garcia, R.; De, Amar K.

2013-09-01

Production of slabs for sour service applications requires stringent control in slab internal quality and secondary processing so as to guarantee resistance against hydrogen-induced cracking (HIC). ArcelorMittal Steelmaking facility at Lazaro Cardenas, Mexico had recently implemented key steelmaking and casting processing technologies for production of sound, centerline free slabs for catering to the growing API Linepipe and off-shore market for sour service applications. State-of-the-art steelmaking with use of residual-free Direct-reduced Iron and continuous casting facilities with dynamic soft reduction were introduced for the production of slabs with ultra clean centerline. Introduction of controlled cooling of slabs for atomic hydrogen control well below 2 ppm has enabled production of slabs suitable for excellent HIC-resistant plate processing. Substantial tonnages of slabs were produced for production of API X52-X65 grade plates and pipes for sour service. Stringent quality control at each stage of steelmaking, casting, and slab inspection ensured slabs with excellent internal quality suitable for HIC resistance to be guaranteed in final product (Plates & Pipes). Details of production steps which resulted in successful HIC-resistant slab production have been described in this article.

Multiphysics modeling of the steel continuous casting process

NASA Astrophysics Data System (ADS)

Hibbeler, Lance C.

This work develops a macroscale, multiphysics model of the continuous casting of steel. The complete model accounts for the turbulent flow and nonuniform distribution of superheat in the molten steel, the elastic-viscoplastic thermal shrinkage of the solidifying shell, the heat transfer through the shell-mold interface with variable gap size, and the thermal distortion of the mold. These models are coupled together with carefully constructed boundary conditions with the aid of reduced-order models into a single tool to investigate behavior in the mold region, for practical applications such as predicting ideal tapers for a beam-blank mold. The thermal and mechanical behaviors of the mold are explored as part of the overall modeling effort, for funnel molds and for beam-blank molds. These models include high geometric detail and reveal temperature variations on the mold-shell interface that may be responsible for cracks in the shell. Specifically, the funnel mold has a column of mold bolts in the middle of the inside-curve region of the funnel that disturbs the uniformity of the hot face temperatures, which combined with the bending effect of the mold on the shell, can lead to longitudinal facial cracks. The shoulder region of the beam-blank mold shows a local hot spot that can be reduced with additional cooling in this region. The distorted shape of the funnel mold narrow face is validated with recent inclinometer measurements from an operating caster. The calculated hot face temperatures and distorted shapes of the mold are transferred into the multiphysics model of the solidifying shell. The boundary conditions for the first iteration of the multiphysics model come from reduced-order models of the process; one such model is derived in this work for mold heat transfer. The reduced-order model relies on the physics of the solution to the one-dimensional heat-conduction equation to maintain the relationships between inputs and outputs of the model. The geometric parameters in the model are calibrated such that the reduced-order model temperatures match a small, periodic subdomain of the mold. These parameters are demonstrated to be insensitive to the calibration conditions. The thermal behavior of the detailed, three-dimensional mold models used in this work can be approximated closely with a few arithmetic calculations after calibrating the reduced-order model of mold heat transfer. The example application of the model includes the effects of the molten steel jet on the solidification front and the ferrostatic pressure. The model is demonstrated to match measurements of mold heat removal and the thickness of a breakout shell all the way around the perimeter of the mold, and gives insight to the cause of breakouts in a beam-blank caster. This multiphysics modeling approach redefines the state of the art of process modeling for continuous casting, and can be~used in future work to explore the formation and prevention of defects and other practical issues. This work also explores the eigen-problem for an arbitrary 3x3 matrix. An explicit, algebraic formula for the eigenvectors is presented.

The effect of surface tension, superheat and surface films on the rate of heat transfer from an iron droplet to a water cooled copper mold

NASA Astrophysics Data System (ADS)

Phinichka, Natthapong

In strip casting the cast surface forms during the initial stage of solidification and the phenomenon that occurs during the first 50 milliseconds of contact time between the liquid steel and the mold define the cast surface and its quality. However the exact mechanism of the initial solidification and the process variables that affect initial solidification phenomena during that time are not well understood. The primary goal of this work is to develop a fundamental understanding of factors controlling strip casting. The purpose of the experimental study is to better understand the role of processing parameters on initial solidification phenomena, heat transfer rate and the formation of the cast steel surface. An investigation was made to evaluate the heat transfer rate of different kinds of steels. The experimental apparatus was designed for millisecond resolution of heat transfer behavior. A novel approach of simultaneous in-situ observation and measurement of rapid heat transfer was developed and enabled a coupling between the interfacial heat transfer rate and droplet solidification rate. The solidification rate was estimated from the varying position of the solidification front as captured by a CCD camera. The effects of experimental parameters such as melt superheat, sulfur content and oxide accumulation at the interface on measured heat flux were studied. It was found that the heat flux increased slightly when the percent of sulfur and increased significantly when superheat increased. The oxide accumulation at the interface was found to be manganese and silicon based oxide. When the liquid steel droplets were ejected onto the copper substrate repeatedly, without cleaning the substrate surface between the ejections, a large increase in the interfacial heat flux was observed. The results of the film study indicated that a liquid oxide film existed at the interface. The surface roughness measurement of the solidified specimen decreased with repeated experimentation and better contact between the droplet and the mold was found to be the cause of the improved heat transfer rate.

40 CFR Table 12 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Continuous Lamination Lines and Continuous Casting Lines Complying With a Lbs/Ton Organic HAP Emissions Limit... Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Lbs... with a lbs/ton organic HAP emissions limit for continuous lamination lines and continuous casting lines...

Tracing the Origin of Non-ferrous Oxides in Lamination Defects on Hot-Rolled Coils: Mold Slag Entrainment vs Submerged Entry Nozzle Reaction Products

NASA Astrophysics Data System (ADS)

Sengo, Sabri; Romano Triguero, Patricia; Zinngrebe, Enno; Mensonides, Fokko

2017-06-01

In this work, lamination defects (slivers) on hot-rolled coils of Ca-treated steel were investigated for microstructure and composition using optical and scanning electron microscopy combined with microanalysis (SEM/EDS). The goal was to identify possible origins for the observed defects which contain a complex assemblage of phases, such as different types of calcium aluminates (CA, CA2, CA6), melilite (C2AS), spinel (MA), and a newly identified phase, CNA2. Mold slag similar to that employed during the cast was absent. Analysis of the bulk composition of some of the defects indicated these to be too rich in alumina to be derived from mold slag through steel-slag redox exchange. In contrast, microstructural observation of the inner side of the submerged entry nozzles (SEN) used during casting showed deposits with compositions comparable to those of the defect material. Based on an estimation of the chemical evolution of mold slag interacting with steel, it is found that the defects are not likely to be entrained mold slag but remobilized SEN deposits, as supported by several microstructural and trace phase criteria. However, it should be noted that extensive reduction of mold slag by steel can lead to compositions rich in sodic-calcic aluminates (CNA2). Therefore, differentiation between specific locations of the defect materials within a casting system requires detailed analysis from the potential sources of origin as well as from the materials found in the defects.

Armor Plate Ballistic Testing

DTIC Science & Technology

1944-08-02

sistanoe to penotration characteristics. However, it is one of the most important factors involved, and when the type of steel , its soundness and its...this test and not to use it in comparing radically differdnt types of plates, such as steel and Dural. Such a comparison can be made only by examining...in many oases, For this reason it became necessary to develop an additional test for the oharaoteristio in rolled armor ( steel "soundness) and cast

24 CFR 3280.604 - Materials.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Material and Property Standard for Special Cast Iron Fittings—IAPMO PS 5-84. Welding and Seamless Wrought Steel Pipe—ANSI/ASME B36.10-1979. Standard Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated, Welded and Seamless—ASTM A53-93. Pipe Threads, General Purpose (Inch)—ANSI/ASME B1.20.1-1983...

The thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies

NASA Technical Reports Server (NTRS)

1982-01-01

The effects of welding, five selected surface coatings, and stress relieving on the thermal fatigue resistance of H-13 Die Steel for aluminum die casting dies were studied using eleven thermal fatigue specimens. Stress relieving was conducted after each 5,000 cycle interval at 1050 F for three hours. Four thermal fatigue specimens were welded with H-13 or maraging steel welding rods at ambient and elevated temperatures and subsequently, subjected to different post-weld heat treatments. Crack patterns were examined at 5,000, 10,000, and 15,000 cycles. The thermal fatigue resistance is expressed by two crack parameters which are the average maximum crack and the average cracked area. The results indicate that a significant improvement in thermal fatigue resistance over the control was obtained from the stress-relieving treatment. Small improvements were obtained from the H-13 welded specimens and from a salt bath nitrogen and carbon-surface treatment. The other surface treatments and welded specimens either did not affect or had a detrimental influence on the thermal fatigue properties of the H-13 die steel.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carpenter, J.A.; Swanson, D.E; Chango, R.F.

Bethlehem Steel's Burns Harbor Div. operates two 89,000-cu ft blast furnaces, D and C, built in 1969 and 1972. These furnaces have been in the forefront of blast furnace performance since they were blown-in. To maintain a credible operation throughout the past 25 years their performance has been improved continuously. Production was increased approximately 3%/year while fuel rate decreased 1%/year. This presentation summarizes the early repairs, relines and improvements that have sustained and enhanced the furnace's performance. The fourth reline of both furnaces will be discussed in detail. As part of the 1991 reline of D furnace its lines weremore » improved and modern penstocks installed. The bosh, tuyere jacket, hearth jacket and both cast floors were replaced. The furnace now has a larger hearth making it easier to control and, liquid level is no longer a problem when pulling the wind to shut down. The new cast floor with its increased trough length has much improved separation of slag from iron and lowered refractory consumption. Since the cast floors on D furnace were changed, there has been a reduction in accidents and absenteeism. This may be related to the change in work practices on the new cast floors. The 1994 reline of C furnace incorporates those improvements made on D furnace in 1991. In addition, C furnace will have high-density cooling which is expected to double its campaign from 6 to 12 years, without interim repairs.« less

Study of the Mechanism of Liquid Slag Infiltration for Lubrication in Slab Continuous Casting

NASA Astrophysics Data System (ADS)

Zhang, Shaoda; Wang, Qiangqiang; He, Shengping; Wang, Qian

2018-04-01

Consistent and uniform lubrication of the solidifying shell, especially in the meniscus, is crucial for the smooth continuous casting operation and production of strands free of surface defects. Thus, the current study established a coupled model to study the inflow behavior of liquid slag to the mold-strand channel, taking the solidification of steel and slag and the periodic oscillation of mold into account. The difficulties and solutions for the simulation were described in detail. The predicted profiles of the slag rim and initial shell were in good agreement with the reports. The main results indicated that liquid slag could be squeezed out and back into the slag pool in a negative strip period while a large amount of liquid slag could infiltrate into the mold-strand channel. Thus, the amount of slag consumed in the negative strip period was relatively small compared with that in the positive strip period. The predicted variation of slag consumption during mold oscillation was periodic, and the average value was 0.274 kg/m2, which agreed well with the slag consumption in industrial practice. The current model can predict and optimize the oscillation parameters aiming at stable lubrication conditions.

Processing of IN-718 Lattice Block Castings

NASA Technical Reports Server (NTRS)

Hebsur, Mohan G.

2002-01-01

Recently a low cost casting method known as lattice block casting has been developed by JAM Corporation, Wilmington, Massachusetts for engineering materials such as aluminum and stainless steels that has shown to provide very high stiffness and strength with only a fraction of density of the alloy. NASA Glenn Research Center has initiated research to investigate lattice block castings of high temperature Ni-base superalloys such as the model system Inconel-718 (IN-718) for lightweight nozzle applications. Although difficulties were encountered throughout the manufacturing process , a successful investment casting procedure was eventually developed. Wax formulation and pattern assembly, shell mold processing, and counter gravity casting techniques were developed. Ten IN-718 lattice block castings (each measuring 15-cm wide by 30-cm long by 1.2-cm thick) have been successfully produced by Hitchiner Gas Turbine Division, Milford, New Hampshire, using their patented counter gravity casting techniques. Details of the processing and resulting microstructures are discussed in this paper. Post casting processing and evaluation of system specific mechanical properties of these specimens are in progress.

Stainless Steel Permeability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buchenauer, Dean A.; Karnesky, Richard A.

An understanding of the behavior of hydrogen isotopes in materials is critical to predicting tritium transport in structural metals (at high pressure), estimating tritium losses during production (fission environment), and predicting in-vessel inventory for future fusion devices (plasma driven permeation). Current models often assume equilibrium diffusivity and solubility for a class of materials (e.g. stainless steels or aluminum alloys), neglecting trapping effects or, at best, considering a single population of trapping sites. Permeation and trapping studies of the particular castings and forgings enable greater confidence and reduced margins in the models. For FY15, we have continued our investigation of themore » role of ferrite in permeation for steels of interest to GTS, through measurements of the duplex steel 2507. We also initiated an investigation of the permeability in work hardened materials, to follow up on earlier observations of unusual permeability in a particular region of 304L forgings. Samples were prepared and characterized for ferrite content and coated with palladium to prevent oxidation. Issues with the poor reproducibility of measurements at low permeability were overcome, although the techniques in use are tedious. Funding through TPBAR and GTS were secured for a research grade quadrupole mass spectrometer (QMS) and replacement turbo pumps, which should improve the fidelity and throughput of measurements in FY16.« less

Mathematical Modeling of High-Temperature Constitutive Equations and Hot Processing Maps for As-Cast SA508-3 Steel

NASA Astrophysics Data System (ADS)

Sui, Dashan; Wang, Tao; Zhu, Lingling; Gao, Liang; Cui, Zhenshan

2016-11-01

The hot deformation behavior and hot workability characteristics of as-cast SA508-3 steel were studied by modeling the constitutive equations and developing hot processing maps. The isothermal compression experiments were carried out at temperatures of 950°C, 1050°C, 1150°C, and 1250°C and strain rates of 0.001 s-1, 0.01 s-1, 0.1 s-1, and 1 s-1 respectively. The two-stage flow stress models were established through the classical theories on work hardening and softening, and the solution of activation energy for hot deformation was 355.0 kJ mol-1 K-1. Based on the dynamic material model, the power dissipation and instability maps were developed separately at strains of 0.2, 0.4, 0.6 and 0.8. The power dissipation rate increases with both the increase of temperature and the decrease of strain rate, and the instable region mainly appears on the conditions of low temperature and high strain rate. The optimal hot working parameters for as-cast SA508-3 steel are 1050-1200°C/0.001-0.1 s-1, with about 25-40% peak efficiency of power dissipation.

Improved and Cost Effective Machining Techniques for Tracked Combat Vehicle Parts

DTIC Science & Technology

1983-10-01

steel is shown in Figure 7-7 and consists of tempered marten- site. Three of the alloys which are used in the gas turbine engine are cast 17 - 4PH ...stainless steel, Inconel 718 and Inconel 713. The 17 - 4PH stainless steel was machined in the solution treated and aged condition. The microstructure as shown...SECURITY CLASS. (of thia report) ISa. DECLASSIFICATION/DOWNGRADING SCHEDULE 16. DISTRIBUTION STATEMENT (of thie Report) 17 . DISTRIBUTION STATEMENT (of

Establishment of a Plasma Melting Manufacturing Process for Production of Nickel-Base Alloys.

DTIC Science & Technology

1975-05-01

7.1 Conclusions 40 7.2 Recommendations 41 8.0 REFERENCES ^2 1 . . . -— - •- - — ■•- lin ■■ - - -- - 1 ^H , r...high nitrogen steel is similar in chemical com- position to the Nitronic series marketed by Armco Steel in the U.S.A. The plasmarc remelted material in...the cast condition displays good ductility and yield strength comparable to Armco’s nitrogen strengthened austenitic steel Nitronic ^0. The Soviet

Solidification Based Grain Refinement in Steels

DTIC Science & Technology

2009-07-24

pearlite (See Figure 1). No evidence of the as-cast austenite dendrite structure was observed. The gating system for this sample resides at the thermal...possible nucleating compounds. 3) Extend grain refinement theory and solidification knowledge through experimental data. 4) Determine structure ...refine the structure of a casting through heat treatment. The energy required for grain refining via thermomechanical processes or heat treatment

Process research into metallic pipe wear of hot chamber die casting machines and methods ofincreasing wear resistance

NASA Astrophysics Data System (ADS)

Mukhametzyanova, G. F.; Kolesnikov, MS; Mukhametzyanov, I. R.; Astatshenko, V. I.

2017-09-01

The kinetics and reasons for metallic pipe wear of hot chamberzinc alloy die casting machines are established.Increasing metallic pipe wear components wear resistance is being achieved by means of die steelДИ - 22 with electroslag remelting modification and electron-beamremelting modification and after the processes of nitriding and boriding besides.

Model Fe-Al Steel with Exceptional Resistance to High Temperature Coarsening. Part II: Experimental Validation and Applications

NASA Astrophysics Data System (ADS)

Zhou, Tihe; Zhang, Peng; O'Malley, Ronald J.; Zurob, Hatem S.; Subramanian, Mani

2015-01-01

In order to achieve a fine uniform grain-size distribution using the process of thin slab casting and directing rolling (TSCDR), it is necessary to control the grain-size prior to the onset of thermomechanical processing. In the companion paper, Model Fe- Al Steel with Exceptional Resistance to High Temperature Coarsening. Part I: Coarsening Mechanism and Particle Pinning Effects, a new steel composition which uses a small volume fraction of austenite particles to pin the growth of delta-ferrite grains at high temperature was proposed and grain growth was studied in reheated samples. This paper will focus on the development of a simple laboratory-scale setup to simulate thin-slab casting of the newly developed steel and demonstrate the potential for grain size control under industrial conditions. Steel bars with different diameters are briefly dipped into the molten steel to create a shell of solidified material. These are then cooled down to room temperature at different cooling rates. During cooling, the austenite particles nucleate along the delta-ferrite grain boundaries and greatly retard grain growth. With decreasing temperature, more austenite particles precipitate, and grain growth can be completely arrested in the holding furnace. Additional applications of the model alloy are discussed including grain-size control in the heat affected zone in welds and grain-growth resistance at high temperature.

Die Soldering in Aluminium Die Casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Q.; Kenik, E.A.; Viswanathan, S.

2000-03-15

Two types of tests, dipping tests and dip-coating tests were carried out on small steel cylinders using pure aluminum and 380 alloy to investigate the mechanism of die soldering during aluminum die casting. Optical and scanning electron microscopy were used to study the morphology and composition of the phases formed during soldering. A soldering mechanism is postulated based on experimental observations. A soldering critical temperature is postulated at which iron begins to react with aluminum to form an aluminum-rich liquid phase and solid intermetallic compounds. When the temperature at the die surface is higher than this critical temperature, the aluminum-richmore » phase is liquid and joins the die with the casting during the subsequent solidification. The paper discusses the mechanism of soldering for the case of pure aluminum and 380 alloy casting in a steel mold, the factors that promote soldering, and the strength of the bond formed when soldering occurs. conditions, an aluminum-rich soldering layer may also form over the intermetallic layer. Although a significant amount of research has been conducted on the nature of these intermetallics, little is known about the conditions under which soldering occurs.« less

An Integrated Study on the Evolution of Inclusions in EH36 Shipbuilding Steel with Mg Addition: From Casting to Welding

NASA Astrophysics Data System (ADS)

Zou, Xiaodong; Zhao, Dapeng; Sun, Jincheng; Wang, Cong; Matsuura, Hiroyuki

2018-04-01

Inclusion evolution behaviors, in terms of composition, size, and number density, and associated influence on the microstructures of the as-cast slabs, rolled plates, and simulated welded samples of plain EH36 and EH36-Mg shipbuilding steels have been systematically investigated. The results indicate that the inclusions in the as-cast plain EH36 are almost Al-Ca-S-O-(Mn) complex oxides with sizes ranging from 1.0 to 2.0 μm. After Mg addition, a large amount of individually fine MnS precipitates and Mg-containing Ti-Al-Mg-O-(Mn-S) complex inclusions are generated, which significantly refine the microstructure and are conducive to the nucleation of acicular ferrite in the rolled and welded sample. Moreover, after rolling and welding thermal simulation, the number of individual MnS decreases gradually due to its precipitation on the surface of Ti-Al-Mg-O oxides.

The effect of welding parameters on penetration in GTA welds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shirali, A.A.; Mills, K.C.

1993-07-01

The effect of various welding parameters on the penetration of GTA welds has been investigated. Increases in welding speed were found to reduce penetration; however, increases in welding current were observed to increase the penetration in high sulfur (HS) casts and decrease penetration in low sulfur (LS) steels. Plots of penetration as a function of increasing linear energy (the heat supplied per unit length of weld) revealed a similar trend with increased penetration in HS casts, but the penetration in LS casts was unaffected by increases in linear energy. These results support the Burgardt-Heiple proposition that changes in welding parametersmore » on penetration can be explained in terms of their effect, sequentially, on the temperature gradient and the Marangoni forces operating in the weld pool. Increases in arc length were found to decrease weld penetration regardless of the sulfur concentration of the steel, and the effects of electrode geometry and welding position on weld penetration were also investigated.« less

Grindability of dental magnetic alloys.

PubMed

Hayashi, Eisei; Kikuchi, Masafumi; Okuno, Osamu; Kimura, Kohei

2005-06-01

In this study, the grindability of cast magnetic alloys (Fe-Pt-Nb magnetic alloy and magnetic stainless steel) was evaluated and compared with that of conventional dental casting alloys (Ag-Pd-Au alloy, Type 4 gold alloy, and cobalt-chromium alloy). Grindability was evaluated in terms of grinding rate (i.e., volume of metal removed per minute) and grinding ratio (i.e., volume ratio of metal removed compared to wheel material lost). Solution treated Fe-Pt-Nb magnetic alloy had a significantly higher grinding rate than the aged one at a grinding speed of 750-1500 m x min(-1). At 500 m x min(-1), there were no significant differences in grinding rate between solution treated and aged Fe-Pt-Nb magnetic alloys. At a lower speed of 500 m x min(-1) or 750 m x min(-1), it was found that the grinding rates of aged Fe-Pt-Nb magnetic alloy and stainless steel were higher than those of conventional casting alloys.

Wide Strip Casting Technology of Magnesium Alloys

NASA Astrophysics Data System (ADS)

Park, W.-J.; Kim, J. J.; Kim, I. J.; Choo, D.

Extensive investigations relating to the production of high performance and low cost magnesium sheet by strip casting have been performed for the application to automotive parts and electronic devices. Research on magnesium sheet production technology started in 2004 by Research Institute of Industrial Science and Technology (RIST) with support of Pohang Iron and Steel Company (POSCO). POSCO has completed the world's first plant to manufacture magnesium coil. Another big project in order to develop wide strip casting technology for the automotive applications of magnesium sheets was started in succession.

The Prediction of Long-Term Thermal Aging in Cast Austenitic Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byun, Thak Sang; Yang, Ying; Lach, Timothy G.

Cast austenitic stainless steel (CASS) materials are extensively used for many massive primary coolant system components of light water reactors (LWRs) including coolant piping, valve bodies, pump casings, and piping elbows. Many of these components are operated in complex and persistently damaging environments of elevated temperature, high pressure, corrosive environment, and sometimes radiation for long periods of time. Since a large number of CASS components are installed in every nuclear power plant and replacing such massive components is prohibitively expensive, any significant degradation in mechanical properties that affects structural integrity, cracking resistance in particular, of CASS components will raise amore » serious concern on the performance of entire power plant. The CASS materials for nuclear components are highly corrosion-resistant Fe-Cr-Ni alloys with 300 series stainless steel compositions and mostly austenite (γ)–ferrite (δ) duplex structures, which result from the casting processes consisting of alloy melting and pouring or injecting liquid metal into a static or spinning mold. Although the commonly used static and centrifugal casting processes enable the fabrication of massive components with proper resistance to environmental attacks, the alloying and microstructural conditions are not highly controllable in actual fabrication, especially in the casting processes of massive components. In the corrosion-resistant Fe-Cr-Ni alloy system, the minor phase (i.e., the δ-ferrite phase) is inevitably formed during the casting process, and is in a non-equilibrium state subject to detrimental changes during exposure to elevated temperature and/or radiation. In general, relatively few critical degradation modes are expected within the current design lifetime of 40 years, given that the CASS components have been processed properly. It has been well known, however, that both the thermal aging and the neutron irradiation can cause degradation of static and impact toughness in the cast stainless steels, and if combined with any flaws formed during the fabrication process or in service, the thermal degradation in CASS components can be a serious concern for the integrity of the power plant. On the integrity of the CASS components during the extended lifetime of 60 years or longer, no conclusive prediction has been possible, primarily because no direct experience with these materials currently exists, and the aging behavior of CASS alloys still remains largely uncertain. The ongoing research for CASS aging, as part of the LWRS Program/Materials Aging and Degradation Pathway, is an integrated research using holistic experimental and modeling means to provide both the scientific understanding on the aging and failure phenomena and the practical models to predict the degree of property degradation.« less

[Variables effecting casting accuracy of quick heating casting investments].

PubMed

Takahashi, H; Nakamura, H; Iwasaki, N; Morita, N; Habu, N; Nishimura, F

1994-06-01

Recently, several new products of investments for "quick heating" have been put on the Japanese market. The total casting procedure time for this quick heating method involves only one hour; 30-minutes waiting after the start of mixing before placing the mold directly into the 700 degrees C furnace and 30-minutes heating in the furnace. The purpose of this study was to evaluate two variables effecting casting accuracy using these new investments. The effect of thickness of the casting liner inside the casting ring and the effect of waiting time before placing the mold into the 700 degrees C furnace were evaluated. A stainless-steel die with a convergence angle of 8 degrees was employed. Marginal discrepancies of the crown between the wax patterns and castings were measured. The size of the cast crown became larger when the thickness of the ring liner was thick and when the waiting time before placing the mold into the furnace was long. These results suggest that these new investments have the advantage of providing sound castings using short-time casting procedures. However, it is necessary to pay careful attention to the casting conditions for obtaining reproducible castings.

Investigation the effect of modification with nanopowders on crystallization process and microstructure of some alloys

NASA Astrophysics Data System (ADS)

Kuzmanov, P. M.; Popov, S. I.; Yovkov, L. V.; Dimitrova, R. N.; Cherepanov, A. N.; Manolov, V. K.

2017-10-01

Modified with nano-powders (NP), AlSi7Mg aluminum alloy, P265GH steel and GG25 gray cast iron, have been investigated. Thermal and metallographic analyses have been made. For modified AlSi7Mg alloy, reduction of overcooling and duration of crystallization at the initial crystallization and their increase at eutectic crystallization have been found. For cast iron GG25, reduction of overcooling at crystallization was established and for P265GH steel, overcooling was not recorded, only a change in the slope of the temperature dependence. The thermal effects obtained in the crystallization correspond to the refinement of micro- and macrostructures. A mathematical model for crystallization of samples for thermal analysis has been developed and solved.

Discussion on design and stress checking of cast-in-place bracket

NASA Astrophysics Data System (ADS)

Xi, Tang Xian; Yong, He; Hu, Sun Shuan

2018-04-01

The cast-in-place bracket is the main support structure in the construction of bridge. Its strength, stiffness and stability have a direct impact on the quality and the safety of bridge construction. The design and calculation of the bracket in the prestressed concrete box girder are analyzed in this paper. The models including Bailey beam, steel crossbeam and steel columns are established by the finite element software. The strength, stiffness and stability of each model under the most unfavorable load are analyzed by MIDAS Civil. The analysis results verify that the support plan meets the relevant specifications and construction requirements. The feasibility of the support scheme was verified well accordingly. The paper can provide reference and guidance for similar engineering construction.

40 CFR 464.35 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) 0.0237 0.0116 Zinc (T) 0.0437 0.0165 (2) Applicable to plants that are casting primarily steel, to... Lead (T) 0.0353 0.0174 Zinc (T) 0.0656 0.025 (b) Casting Quench Operations. (1) Applicable to plants... Copper (T) 0.0138 0.0076 Lead (T) 0.0252 0.0124 Zinc (T) 0.0466 0.0176 TTO 0.0257 0.00838 Oil and grease...

40 CFR 464.35 - Pretreatment standards for existing sources.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) 0.0237 0.0116 Zinc (T) 0.0437 0.0165 (2) Applicable to plants that are casting primarily steel, to... Lead (T) 0.0353 0.0174 Zinc (T) 0.0656 0.025 (b) Casting Quench Operations. (1) Applicable to plants... Copper (T) 0.0138 0.0076 Lead (T) 0.0252 0.0124 Zinc (T) 0.0466 0.0176 TTO 0.0257 0.00838 Oil and grease...

Tensile fracture of coarse-Grained cast austenitic manganese steels

NASA Astrophysics Data System (ADS)

Rittel, D.; Roman, I.

1988-09-01

Tensile fracture of coarse-grained (0.25 to 1 mm) cast austenitic manganese (Hadfield) steels has been investigated. Numerous surface discontinuities nucleate in coarse slip bands, on the heavily deformed surface of tensile specimens. These discontinuities do not propagate radially and final fracture results from central specimen cracking at higher strains. On the microscopic scale, bulk voids nucleate during the entire plastic deformation and they do not coalesce by shear localization (e.g., void-sheet) mechanism. Close voids coalesce by internal necking, whereas distant voids are bridged by means of small voids which nucleate at later stages of the plastic deformation. The high toughness of Hadfield steels is due to their high strain-hardening capacity which stabilizes the plastic deformation, and avoids shear localization and loss of load-bearing capacity. The observed dependence of measured mechanical properties on the specimen’s geometry results from the development of a surface layer which charac-terizes the deformation of this coarse-grained material.

Development of an Innovative Laser-Assisted Coating Process for Extending Lifetime of Metal Casting Dies. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madhav Rao Gonvindaraju

1999-10-18

Die casting dies used in the metal casting industry fail due to thermal fatigue cracking accompanied by the presence of residual tensile stresses, corrosion, erosion and wear of die surfaces. This phase 1 SBIR Final Report summarize Karta Technologies research involving the development of an innovative laser coating technology for metal casting dies. The process involves depositing complex protective coatings of nanocrystalline powders of TiC followed by a laser shot peening. The results indicate a significant improvement in corrosion and erosion resistance in molten aluminum for H13 die casting die steels. The laser-coated samples also showed improved surface finish, amore » homogeneous and uniform coating mircrostructure. The technology developed in this research can have a significant impact on the casting industry by saving the material costs involved in replacing dies, reducing downtime and improving the quality.« less

CRADA Final Report for CRADA Number NFE-08-01671 Materials for Advanced Turbocharger Designs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maziasz, P. J.; Wilson, M.

2014-11-28

Results were obtained on residual stresses in the weld of the steel shaft to the Ni-based superalloy turbine wheel for turbochargers. Neutron diffraction studies at the HFIR Residual Stress Facility showed asymmetric tensile stresses after electron-beam welding of the wheel and shaft. A post-weld heat-treatment was found to relieve and reduce the residual stresses. Results were also obtained on cast CF8C-Plus steel as an upgrade alternative to cast irons (SiMo, Ni-resist) for higher temperature capability and performance for the turbocharger housing. CF8C-Plus steel has demonstrated creep-rupture resistance at 600-950oC, and is more creep-resistant than HK30Nb, but lacks oxidation-resistance at 800oCmore » and above in 10% water vapor. New modified CF8C-Plus Cu/W steels with Cr and Ni additions show better oxidation resistance at 800oC in 10% water vapor, and have capability to higher temperatures. For automotive gasoline engine turbocharger applications, higher temperatures are required, so at the end of this project, testing began at 1000oC and above.« less

Low-Temperature Aging Characteristics of Type 316L Stainless Steel Welds: Dependence on Solidification Mode

NASA Astrophysics Data System (ADS)

Abe, Hiroshi; Watanabe, Yutaka

2008-06-01

Thermal aging embrittlement of light water reactor (LWR) components made of stainless steel cast has been recognized as a potential degradation issue, and careful attention has been paid to it. Although welds of austenitic stainless steels have γ-δ duplex microstructure, which is similar to that of the stainless steel cast, examination of the thermal aging characteristics of the stainless steel welds is very limited. In this investigation, two types of type 316L stainless steel weld metal with different solidification modes were prepared using two kinds of filler metals having tailored Ni equivalent and Cr equivalent. Differences between the two weld metals in the morphology of microstructure, in the composition of δ-ferrite, and in hardening behaviors with isothermal aging at 335 °C have been investigated. The hardness of the ferrite phase has increased with aging time, while the hardness of austenite phase has stayed the same. The mottled aspect has been observed in δ-ferrite of aged samples by transmission electron microscopy (TEM) observation. These characteristics suggest that spinodal decomposition has occurred in δ-ferrite by aging at 335 °C. The age-hardening rate of δ-ferrite was faster for the primary austenite solidification mode (AF mode) sample than the primary ferrite solidification mode (FA mode) sample in the initial stage of the aging up to 2000 hours. It has been suggested that the solidification mode can affect the kinetics of spinodal decomposition.

The effect of zinc (Zn) content to cell potential value and efficiency aluminium sacrificial anode in 0.2 M sulphuric acid environment

NASA Astrophysics Data System (ADS)

Akranata, Ahmad Ridho; Sulistijono, Awali, Jatmoko

2018-04-01

Sacrificial anode is sacirifial component that used to protect steel from corrosion. Generally, the component are made of aluminium and zinc in water environment. Sacrificial anode change the protected metal structure become cathodic with giving current. The advantages of aluminium is corrosion resistance, non toxicity and easy forming. Zinc generally used for coating in steel to prevent steel from corrosion. This research was conducted to analyze the effect of zinc content to the value of cell potential and efficiency aluminium sacrificial anode with sand casting method in 0.2 M sulphuric acid environment. The sacrificial anode fabrication made with alloying aluminium and zinc metals with variation composition of alloy with pure Al, Al-3Zn, Al-6Zn, and Al-9Zn with open die sand casting process. The component installed with ASTM A36 steel. After the research has been done the result showed that addition of zinc content increase the cell potential, protection efficiency, and anode efficiency from steel plate. Cell potential value measurement and weight loss measurement showed that addition of zinc content increase the cell potential value into more positive that can protected the ASTM A36 steel more efficiently that showed in weight loss measurement where the protection efficiency and anodic efficiency of Al-9Zn sacrificial anode is better than protection efficiency and anodic efficiency of pure Al. The highest protection efficiency gotten by Al-9Zn alloy

Quantitative examination of carbide and sulphide precipitates in chemically complex steels processed by direct strip casting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dorin, Thomas, E-mail: thomas.dorin@deakin.edu.au; Wood, Kathleen; Taylor, Adam

2016-02-15

A high strength low alloy steel composition has been melted and processed by two different routes: simulated direct strip casting and slow cooled ingot casting. The microstructures were examined with scanning and transmission electron microscopy, atom probe tomography and small angle neutron scattering (SANS). The formation of cementite (Fe{sub 3}C), manganese sulphides (MnS) and niobium carbo-nitrides (Nb(C,N)) was investigated in both casting conditions. The sulphides were found to be significantly refined by the higher cooling rate, and developed an average diameter of only 100 nm for the fast cooled sample, and a diameter too large to be measured with SANSmore » in the slow cooled condition (> 1.1 μm). Slow cooling resulted in the development of classical Nb(C,N) precipitation, with an average diameter of 7.2 nm. However, after rapid cooling both the SANS and atom probe tomography data indicated that the Nb was retained in the matrix as a random solid solution. There was also some evidence that O, N and S are also retained in solid solution in levels not found during conventional processing. - Highlights: • The influence of cooling rate on microstructure is investigated in a HSLA steel. • SANS, TEM and APT are used to characterise the sulphides and Nb(C,N) precipitates. • The slow cooling rate result in the formation of Nb(C,N) precipitates. • The fast cooling rate results in a microstructure supersaturated in Nb, C and N. • The sulphides are 100 nm in the fast cooled sample and > 1 μm in the slow cooled one.« less

Mapping the global flow of steel: from steelmaking to end-use goods.

PubMed

Cullen, Jonathan M; Allwood, Julian M; Bambach, Margarita D

2012-12-18

Our society is addicted to steel. Global demand for steel has risen to 1.4 billion tonnes a year and is set to at least double by 2050, while the steel industry generates nearly a 10th of the world's energy related CO₂ emissions. Meeting our 2050 climate change targets would require a 75% reduction in CO₂ emissions for every tonne of steel produced and finding credible solutions is proving a challenge. The starting point for understanding the environmental impacts of steel production is to accurately map the global steel supply chain and identify the biggest steel flows where actions can be directed to deliver the largest impact. In this paper we present a map of global steel, which for the first time traces steel flows from steelmaking, through casting, forming, and rolling, to the fabrication of final goods. The diagram reveals the relative scale of steel flows and shows where efforts to improve energy and material efficiency should be focused.

Contributions of Rare Earth Element (La,Ce) Addition to the Impact Toughness of Low Carbon Cast Niobium Microalloyed Steels

NASA Astrophysics Data System (ADS)

Torkamani, Hadi; Raygan, Shahram; Garcia Mateo, Carlos; Rassizadehghani, Jafar; Palizdar, Yahya; San-Martin, David

2018-07-01

In this research Rare Earth elements (RE), La and Ce (200 ppm), were added to a low carbon cast microalloyed steel to disclose their influence on the microstructure and impact toughness. It is suggested that RE are able to change the interaction between the inclusions and matrix during the solidification process (comprising peritectic transformation), which could affect the microstructural features and consequently the impact property; compared to the base steel a clear evolution was observed in nature and morphology of the inclusions present in the RE-added steel i.e. (1) they changed from MnS-based to (RE,Al)(S,O) and RE(S)-based; (2) they obtained an aspect ratio closer to 1 with a lower area fraction as well as a smaller average size. Besides, the microstructural examination of the matrix phases showed that a bimodal type of ferrite grain size distribution exists in both base and RE-added steels, while the mean ferrite grain size was reduced from 12 to 7 μm and the bimodality was redressed in the RE-added steel. It was found that pearlite nodule size decreases from 9 to 6 μm in the RE-added steel; however, microalloying with RE caused only a slight decrease in pearlite volume fraction. After detailed fractography analyses, it was found that, compared to the based steel, the significant enhancement of the impact toughness in RE-added steel (from 63 to 100 J) can be mainly attributed to the differences observed in the nature of the inclusions, the ferrite grain size distribution, and the pearlite nodule size. The presence of carbides (cementite) at ferrite grain boundaries and probable change in distribution of Nb-nanoprecipitation (promoted by RE addition) can be considered as other reasons affecting the impact toughness of steels under investigation.

Contributions of Rare Earth Element (La,Ce) Addition to the Impact Toughness of Low Carbon Cast Niobium Microalloyed Steels

NASA Astrophysics Data System (ADS)

Torkamani, Hadi; Raygan, Shahram; Garcia Mateo, Carlos; Rassizadehghani, Jafar; Palizdar, Yahya; San-Martin, David

2018-03-01

In this research Rare Earth elements (RE), La and Ce (200 ppm), were added to a low carbon cast microalloyed steel to disclose their influence on the microstructure and impact toughness. It is suggested that RE are able to change the interaction between the inclusions and matrix during the solidification process (comprising peritectic transformation), which could affect the microstructural features and consequently the impact property; compared to the base steel a clear evolution was observed in nature and morphology of the inclusions present in the RE-added steel i.e. (1) they changed from MnS-based to (RE,Al)(S,O) and RE(S)-based; (2) they obtained an aspect ratio closer to 1 with a lower area fraction as well as a smaller average size. Besides, the microstructural examination of the matrix phases showed that a bimodal type of ferrite grain size distribution exists in both base and RE-added steels, while the mean ferrite grain size was reduced from 12 to 7 μm and the bimodality was redressed in the RE-added steel. It was found that pearlite nodule size decreases from 9 to 6 μm in the RE-added steel; however, microalloying with RE caused only a slight decrease in pearlite volume fraction. After detailed fractography analyses, it was found that, compared to the based steel, the significant enhancement of the impact toughness in RE-added steel (from 63 to 100 J) can be mainly attributed to the differences observed in the nature of the inclusions, the ferrite grain size distribution, and the pearlite nodule size. The presence of carbides (cementite) at ferrite grain boundaries and probable change in distribution of Nb-nanoprecipitation (promoted by RE addition) can be considered as other reasons affecting the impact toughness of steels under investigation.

Evaluation of marginal and internal gaps of metal ceramic crowns obtained from conventional impressions and casting techniques with those obtained from digital techniques.

PubMed

Rai, Rathika; Kumar, S Arun; Prabhu, R; Govindan, Ranjani Thillai; Tanveer, Faiz Mohamed

2017-01-01

Accuracy in fit of cast metal restoration has always remained as one of the primary factors in determining the success of the restoration. A well-fitting restoration needs to be accurate both along its margin and with regard to its internal surface. The aim of the study is to evaluate the marginal fit of metal ceramic crowns obtained by conventional inlay casting wax pattern using conventional impression with the metal ceramic crowns obtained by computer-aided design and computer-aided manufacturing (CAD/CAM) technique using direct and indirect optical scanning. This in vitro study on preformed custom-made stainless steel models with former assembly that resembles prepared tooth surfaces of standardized dimensions comprised three groups: the first group included ten samples of metal ceramic crowns fabricated with conventional technique, the second group included CAD/CAM-milled direct metal laser sintering (DMLS) crowns using indirect scanning, and the third group included DMLS crowns fabricated by direct scanning of the stainless steel model. The vertical marginal gap and the internal gap were evaluated with the stereomicroscope (Zoomstar 4); post hoc Turkey's test was used for statistical analysis. One-way analysis of variance method was used to compare the mean values. Metal ceramic crowns obtained from direct optical scanning showed the least marginal and internal gap when compared to the castings obtained from inlay casting wax and indirect optical scanning. Indirect and direct optical scanning had yielded results within clinically acceptable range.

The influence of tempering process for DP lateritic steel in hardness and microstructure behavior

NASA Astrophysics Data System (ADS)

Hasbi, Muhammad Yunan; Saefudin, Romijarso, Toni Bambang

2018-05-01

In this study, the influence of tempering temperature on dual phase (DP) steel lateritic has been examined. Lateritic is chosen because of its excellence as austenite stabilizer in the formation of martensite and also increase the weldability due to nickel content. The hardness and microstructure behavior of steels were the main focus of this research. One of the goals was to obtain the combination of high strength and ductile materials for automotive application. The specimens used in this study were low carbon steel made by the hot-rolled process and followed by the initial heating process with various temperature (760 °C, 800 °C, 840 °C) continued with rapid cooling. The specimens also conducted by secondary heating with tempering process at 450 °C in an hour with very slow cooling. The experimental results showed that correlation between temperatures with hardness properties of materials. The hardness of the specimens increases as temperature increases. It was because austenite phase has a sufficient time and temperature to form, therefore the amount of transformed austenite becomes martensite was greater. The highest hardness reached by T = 840 °C was 46.98 HRC, it was about 153% from as cast (18.54 HRC). Decreasing in hardness value when the specimen was tempering at 450 °C indicated that martensite phase has been transformed into tempered martensite.

Characterization of the interfacial heat transfer coefficient for hot stamping processes

NASA Astrophysics Data System (ADS)

Luan, Xi; Liu, Xiaochuan; Fang, Haomiao; Ji, Kang; El Fakir, Omer; Wang, LiLiang

2016-08-01

In hot stamping processes, the interfacial heat transfer coefficient (IHTC) between the forming tools and hot blank is an essential parameter which determines the quenching rate of the process and hence the resulting material microstructure. The present work focuses on the characterization of the IHTC between an aluminium alloy 7075-T6 blank and two different die materials, cast iron (G3500) and H13 die steel, at various contact pressures. It was found that the IHTC between AA7075 and cast iron had values 78.6% higher than that obtained between AA7075 and H13 die steel. Die materials and contact pressures had pronounced effects on the IHTC, suggesting that the IHTC can be used to guide the selection of stamping tool materials and the precise control of processing parameters.

Thermo-mechanical process for treatment of welds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malik, R K

1980-03-01

Benefits from thermo-mechanical processing (TMP) of austenitic stainless steel weldments, analogous to hot isostatic pressing (HIP) of castings, most likely result from compressive plastic deformation, enhanced diffusion, and/or increased dislocation density. TMP improves ultrasonic inspectability of austenitic stainless steel welds owing to: conversion of cast dendrites into equiaxed austenitic grains, reduction in size and number of stringers and inclusions, and reduction of delta ferrite content. TMP induces structural homogenization and healing of void-type defects and thus contributes to an increase in elongation, impact strength, and fracture toughness as well as a significant reduction in data scatter for these properties. Anmore » optimum temperature for TMP or HIP of welds is one which causes negligible grain growth and an acceptable reduction in yield strength, and permits healing of porosity.« less

[The industrial environment in the electric-furnace steel smelting, converter and open-hearth furnace methods of manufacturing manganese-alloyed steels].

PubMed

Karnaukh, N G; Petrov, G A; Gapon, V A; Poslednichenko, I P; Shmidt, S E

1992-01-01

Inspection of the environment in manganese-alloyed steel production showed inadequate hygienic conditions of the technological processes employed. Air was more polluted by manganese oxides during the oxygen-converter process though their highest concentrations, 38 times exceeding the MAS, appeared during the casting of steel. An electric furnace coated by dust-noise-proof material and gas cleaning is preferable from a hygienic point of view. The influence of unfavourable microclimate, intensive infrared irradiation and loud noise on workers necessitates automation and mechanization of the process in order to improve the working conditions.

Development of the Electromagnetic Continuous Casting Technology for of Magnesium Alloys

NASA Astrophysics Data System (ADS)

Park, Joon-Pyo; Kim, Myoung-Gyun; Kim, Jong-Ho; Lee, Gyu-Chang

Currently, magnesium billets produced by ingot casting or direct chill casting process, result in low-quality surfaces and low productivity, Continuous casting technology to solve these problem has not only high-quality surface billets with fine-grained and homogeneous microstructure but also cost down. The latent heat of fusion per weight (J/g) of magnesium is similar to other metals, however, considering the heat emitted to the mold surface during continuous casting in meniscus region and converting it to the latent heat of fusion per volume, magnesium will be rapidly solidified in the mold during continuous casting, which induces subsequent surface defect formation. In this study, electromagnetic casting and stirring (EMC and EMS) techniques are proposed to control solidification process conveniently by compensating the low latent heat of solidification by volume and to fabricate magnesium billet with high-quality surface. This technique was extended to large scale billets up to 300 mm diameter and continuous casting was successfully conducted. Then magnesium billet was used for the fabrication of prototype automobile pulley.

An Electron-Diffraction Examination of Cast-Iron Piston Rings from Single-Cylinder Aircraft-Engine Tests

DTIC Science & Technology

1945-02-01

found t; a great extent on thn ueed cylinder barrel ( SAE 4140 steel) and to a lesser extent on the top ohrmne- plated ring of the aesembl.yafter it had...on the used cylinder barrel (W 4140 steel) used in the tests and, to a lesser extent, on the used top chrome-platedring of the piston assembly. The

[Mineral migration from stainless steel, cast iron and soapstone (steatite) Brazilian pans to food preparations].

PubMed

Quintaes, Késia Diego; Farfan, Jaime Amaya; Tomazini, Fernanda Mariana; Morgano, Marcelo Antônio

2006-09-01

Culinary utensils may release some inorganic elements during food preparation. Mineral migration can be beneficial for as long as it occurs in amounts adequate to the needs of the consumer or no toxicological implications are involved. In this study, the migrations of Fe, Mg, Mn, Cr, Ni and Ca, along seven cooking cycles were evaluated for two food preparations (polished rice and commercial tomato sauce, the latter as an acid food), performed in unused stainless steel, cast iron and soapstone pans, taking refractory glass as a blank. Minerals were determined by inductively coupled plasma optical emission spectrometry (ICP OES). The utensils studied exhibited different rates, patterns and variability of migration depending on the type of food. Regression analysis of the data revealed that, as a function of the number of cycles, the iron pans released increasing amounts of iron when tomato sauce was cooked (y = 70.76x + 276.75; R2 = 0.77). The soapstone pans released calcium (35 and 26 mg/kg), magnesium (25 and 15 mg/kg) into the tomato sauce and rice preparations, respectively. Additionally, the commercial tomato sauce drew manganese (3.9 and 0.6 mg/kg) and some undesirable nickel (1.0 mg/kg) from the soapstone material, whereas the stainless steel pans released nickel at a lower rate than steatite and in a diminishing fashion with the number o cooking cycles, while still transferring some iron and chromium to the food. We conclude that while cast iron and glass could be best for the consumer's nutritional health, stainless steel and steatite can be used with relatively low risk, provided acid foods are not routinely prepared in those materials.

Thermally Stable Nanocrystalline Steel

NASA Astrophysics Data System (ADS)

Hulme-Smith, Christopher Neil; Ooi, Shgh Woei; Bhadeshia, Harshad K. D. H.

2017-10-01

Two novel nanocrystalline steels were designed to withstand elevated temperatures without catastrophic microstructural changes. In the most successful alloy, a large quantity of nickel was added to stabilize austenite and allow a reduction in the carbon content. A 50 kg cast of the novel alloy was produced and used to verify the formation of nanocrystalline bainite. Synchrotron X-ray diffractometry using in situ heating showed that austenite was able to survive more than 1 hour at 773 K (500 °C) and subsequent cooling to ambient temperature. This is the first reported nanocrystalline steel with high-temperature capability.

Development of High-Performance Cast Crankshafts. Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bauer, Mark E

The objective of this project was to develop technologies that would enable the production of cast crankshafts that can replace high performance forged steel crankshafts. To achieve this, the Ultimate Tensile Strength (UTS) of the new material needs to be 850 MPa with a desired minimum Yield Strength (YS; 0.2% offset) of 615 MPa and at least 10% elongation. Perhaps more challenging, the cast material needs to be able to achieve sufficient local fatigue properties to satisfy the durability requirements in today’s high performance gasoline and diesel engine applications. The project team focused on the development of cast steel alloysmore » for application in crankshafts to take advantage of the higher stiffness over other potential material choices. The material and process developed should be able to produce high-performance crankshafts at no more than 110% of the cost of current production cast units, perhaps the most difficult objective to achieve. To minimize costs, the primary alloy design strategy was to design compositions that can achieve the required properties with minimal alloying and post-casting heat treatments. An Integrated Computational Materials Engineering (ICME) based approach was utilized, rather than relying only on traditional trial-and-error methods, which has been proven to accelerate alloy development time. Prototype melt chemistries designed using ICME were cast as test specimens and characterized iteratively to develop an alloy design within a stage-gate process. Standard characterization and material testing was done to validate the alloy performance against design targets and provide feedback to material design and manufacturing process models. Finally, the project called for Caterpillar and General Motors (GM) to develop optimized crankshaft designs using the final material and manufacturing processing path developed. A multi-disciplinary effort was to integrate finite element analyses by engine designers and geometry-specific casting simulations with existing materials models to optimize crankshaft cost and performance. Prototype crankshafts of the final design were to be produced and validated using laboratory bench testing and on-engine durability testing. ICME process simulation tools were used to investigate a broad range of processing concepts. These concepts included casting orientation, various mold and core materials, and various filling and feeding strategies. Each crankshaft was first simulated without gating and risers, which is termed natural solidification. The natural solidification results were used as a baseline for strategy development of each concept. Casting process simulations and ICME tools were proven to be reasonable predictors of real world results. Potential alloys were developed that could meet the project material property goals with appropriate normalization and temper treatments. For the alloys considered, post-normalization temper treatments proved to be necessary to achieve the desired yield strengths and elongations and appropriate heat treatments were designed using ICME tools. The experimental data of all the alloys were analyzed in combination with ICME tools to establish chemistry-process-structure relations. Several GM small gas engine (SGE) crankshafts were successfully cast in sand molds using two different sprue, runner, gate, riser, chill designs. These crankshafts were cast in two different steel alloys developed during the project, but casting finishing (e.g. riser removal) remains a cost challenge. A long list of future work was left unfinished when this project was unexpectedly terminated.« less

Microstructure, texture evolution and magnetic properties of strip-casting non-oriented 6.5 wt.% Si electrical steel doped with cerium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Hai-Tao; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn

A 0.3 mm thick non-oriented 6.5 wt.% Si electrical steel sheet doped with cerium is produced by twin-roll strip casting, hot rolling, warm rolling and annealing. A detailed study of the cerium precipitates in the as-cast strip, microstructure and texture evolution at different processing stages is carried out by electron probe micro-analysis, optical microscopy, X-ray diffraction and electron backscattered diffraction analysis. Grain interior distributing precipitates identified as Ce-oxides, Ce-oxysulfides and Ce-phosphides, and boundary distributing Ce-oxides and Ce-phosphides are observed in the as-cast strip. The initial as-cast strip is characterized by a much finer solidification microstructure and dominated by obvious //ND texture through the strip thickness. After hot and warm rolling, inhomogeneous microstructure containing large amounts of in-grain shear bands is characterized by mixed < 110 >//RD and < 111 >//ND textures. The texture of the annealed sheet with a relatively large average grain size is far more optimized by the domination of the beneficial cube, rotated cube, (001)< 120 > to (001)< 130 > and Goss texture components, and the elimination of the detrimental γ-fiber texture, leading to a superior magnetic induction and improved iron loss. - Highlights: • An Fe–6.5 wt.% Si as-cast strip doped with cerium was produced. • A thin warm rolled sheet with limited edge cracks was obtained. • Microstructure and texture evolution at each stage were investigated. • Strong λ-fiber and Goss recrystallization textures were formed. • The magnetic properties of the annealed sheet were significantly improved.« less

A Review of In Situ Observations of Crystallization and Growth in High Temperature Oxide Melts

NASA Astrophysics Data System (ADS)

Wang, Zhanjun; Sohn, Il

2018-05-01

This review summarizes the significant results of high-temperature confocal laser scanning microscopy (CLSM) and single hot thermocouple technology (SHTT) and its application in observing the crystallization and growth in high-temperature oxide melts from iron- and steel-making slags to continuous casting mold fluxes. Using in situ observations of CLSM and SHTT images of high-temperature molten oxides with time, temperature, and composition, the crystallization behavior, including crystal morphology, crystallization temperature, initial nucleation and growth rate, could be obtained. The broad range of applications using in situ observations during crystallization have provided a wealth of opportunities in pyrometallurgy and is provided in this review.

View southwest of 350ton crane, showing one of four castings ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View southwest of 350-ton crane, showing one of four castings which support a stationary, tapered steel girder structure called a "tower". This tower is located within an outer rotating framework designated as the "pintle" of the 350-ton crane. The whole crane pivots around bearing at the top of this tapered support tower. - Naval Base Philadelphia-Philadelphia Naval Shipyard, 350-Ton Hammerhead Crane, League Island, Philadelphia, Philadelphia County, PA

The influence of aluminum and carbon on the abrasion resistance of high manganese steels

NASA Astrophysics Data System (ADS)

Buckholz, Samuel August

Abrasive wear testing of lightweight, austenitic Fe-Mn-Al-C cast steel has been performed in accordance with ASTM G65 using a dry sand, rubber wheel, abrasion testing apparatus. Testing was conducted on a series of Fe-30Mn-XAl-YC-1Si-0.5Mo chemistries containing aluminum levels from 2.9 to 9.5 wt.% and carbon levels from 0.9 to 1.83 wt.%. Solution treated materials having an austenitic microstructure produced the highest wear resistance. Wear resistance decreased with higher aluminum, lower carbon, and higher hardness after age hardening. In the solution treated condition the wear rate was a strong function of the aluminum to carbon ratio and the wear rate increased with a parabolic dependence on the Al/C ratio, which ranged from 1.8 to 10.2. Examination of the surface wear scar revealed a mechanism of plowing during abrasion testing and this method of material removal is sensitive to work hardening rate. Work hardening behavior was determined from tensile tests and also decreased with increasing Al/C ratio and after aging hardening. The loss of wear resistance is related to short range ordering of Al and C in the solution treated materials and kappa-carbide precipitation in age hardened materials and both contribute to planar slip and lower work hardening rates. A high carbon tool steel (W1) and a bainitic low alloy steel (SAE 8620) were also tested for comparison. A lightweight steel containing 6.5 wt.% Al and 1.2 wt.% C has wear resistance comparable to within 5% of the bainitic SAE 8620 steel forging currently used for the Bradley Fighting Vehicle track shoe and this cast Fe-Mn-Al-C steel, at equivalent tensile properties, would be 10% lighter.

Analysis of Mold Friction in a Continuous Casting Using Wavelet Transform

NASA Astrophysics Data System (ADS)

Ma, Yong; Fang, Bohan; Ding, Qiqi; Wang, Fangyin

2018-04-01

Mold friction (MDF) is an important parameter reflecting the lubrication condition between the initial shell and the mold during continuous casting. In this article, based on practical MDF from the slab continuous casting driven by a mechanical vibration device, the characteristics of friction were analyzed by continuous wavelet transform (CWT) and discrete wavelet transform (DWT) in different casting conditions, such as normal casting, level fluctuation, and alarming of the temperature measurement system. The results show that the CWT of friction accurately captures the subtle changes in friction force, such as the periodic characteristic of MDF during normal casting and the disordered feature of MDF during level fluctuation. Most important, the results capture the occurrence of abnormal casting and display the friction frequency characteristics at this abnormal time. In addition, in this article, there are some abnormal casting conditions, and the friction signal is stable until there is a sudden large change when abnormal casting, such as split breakout and submerged entry nozzle breakage, occurs. The DWT has a good ability to capture the friction characteristics for such abnormal situations. In particular, the potential abnormal features of MDF were presented in advance, which provides strong support for identifying abnormal casting and even preventing abnormal casting.

49 CFR 192.557 - Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of...

Code of Federal Regulations, 2010 CFR

2010-10-01

... produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines. 192... § 192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent... will produce a hoop stress less than 30 percent of SMYS and that is above the previously established...

49 CFR 192.557 - Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of...

Code of Federal Regulations, 2013 CFR

2013-10-01

... produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines. 192... § 192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent... will produce a hoop stress less than 30 percent of SMYS and that is above the previously established...

49 CFR 192.557 - Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of...

Code of Federal Regulations, 2014 CFR

2014-10-01

... produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines. 192... § 192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent... will produce a hoop stress less than 30 percent of SMYS and that is above the previously established...

49 CFR 192.557 - Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of...

Code of Federal Regulations, 2012 CFR

2012-10-01

... produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines. 192... § 192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent... will produce a hoop stress less than 30 percent of SMYS and that is above the previously established...

High Yield Strength Cast Steel With Improved Weldability

DTIC Science & Technology

1991-05-01

Transformation ( CCT ) diagram presented in Figure 25. It is clear that these low carbon steels generally will produce martensite and~or bainite over a very wide...microstructure. The CCT diagram developed from the Gleeble evaluations appears to indicate a martensite start (MJ temperature of approximately 800° F...Regardless of the exact identity of the transformation products, the CCT diagram contains the features desired for the experimental alloy system

JPRS Report. Soviet Union: World Economy & International Relations, No. 2, February 1989

DTIC Science & Technology

1989-05-13

a small group of the biggest companies of a number of highly concentrated base sectors of industry—steel casting, automotive, chemical , industrial...forth. As of the present the TNC practically share among themselves the capitalist markets for automobiles and steel and a number of chemical ...automobile, textile, chemical and agricultural commodity, electronics and transport services markets. Competition is now heating up not only in the sphere of

ACES. Accelerated Corrosion Expert Simulator

DTIC Science & Technology

2010-02-01

Composites Coating Systems Organic Inorganic Ceramic Materials 22 Inputs and Dimensions Xi Thickness Hardness Strength Ductility Abrasion Resistance...GPU 25 T-Handle Latch 10-Year ACT Material/ Coating Configuration Die Cast Zinc T-Handle Carbon Steel Pin CS Shank CS T-Washer Carbon Steel Dish E- coat ...CARC Zinc Plating Cadmium Plated BoltE- coat /CARC CS Panel CS Panel O-Ring E- coat /CARC Original (10-year ACT) Design Green Flag Color Qualitative

49 CFR 192.557 - Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent of...

Code of Federal Regulations, 2011 CFR

2011-10-01

... produce a hoop stress less than 30 percent of SMYS: plastic, cast iron, and ductile iron pipelines. 192... § 192.557 Uprating: Steel pipelines to a pressure that will produce a hoop stress less than 30 percent... will produce a hoop stress less than 30 percent of SMYS and that is above the previously established...

Understanding the Interaction between a Steel Microstructure and Hydrogen

PubMed Central

Depover, Tom; Laureys, Aurélie; Wallaert, Elien

2018-01-01

The present work provides an overview of the work on the interaction between hydrogen (H) and the steel’s microstructure. Different techniques are used to evaluate the H-induced damage phenomena. The impact of H charging on multiphase high-strength steels, i.e., high-strength low-alloy (HSLA), transformation-induced plasticity (TRIP) and dual phase (DP) is first studied. The highest hydrogen embrittlement resistance is obtained for HSLA steel due to the presence of Ti- and Nb-based precipitates. Generic Fe-C lab-cast alloys consisting of a single phase, i.e., ferrite, bainite, pearlite or martensite, and with carbon contents of approximately 0, 0.2 and 0.4 wt %, are further considered to simplify the microstructure. Finally, the addition of carbides is investigated in lab-cast Fe-C-X alloys by adding a ternary carbide forming element to the Fe-C alloys. To understand the H/material interaction, a comparison of the available H trapping sites, the H pick-up level and the H diffusivity with the H-induced mechanical degradation or H-induced cracking is correlated with a thorough microstructural analysis. PMID:29710803

Low Cost Al-Si Casting Alloy As In-Situ Composite for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.

2000-01-01

A new aluminum-silicon (Al-Si) alloy has been successfully developed at NASA- Marshall Space Flight Center (MSFC) that has significant improvement in tensile and fatigue strength at elevated temperatures (500 F-700 F). The alloy offers a number of benefits such as light weight, high hardness, low thermal expansion and high surface wear resistance. In hypereutectic form, this alloy is considered as an in-situ Al-Si composite with tensile strength of about 90% higher than the auto industry 390 alloy at 600 F. This composite is very economically produced by using either conventional permanent steel molds or die casting. The projected material cost is less than $0.90 per pound, and automotive components such as pistons can be cast for high production rate using conventional casting techniques with a low and fully accounted cost. Key Words: Metal matrix composites, In-situ composite, aluminum-silicon alloy, hypereutectic alloy, permanent mold casting, die casting.

A comparison of the accuracy of polyether, polyvinyl siloxane, and plaster impressions for long-span implant-supported prostheses.

PubMed

Hoods-Moonsammy, Vyonne J; Owen, Peter; Howes, Dale G

2014-01-01

The purpose of this study was to compare the capacity of different impression materials to accurately reproduce the positions of five implant analogs on a master model by comparing the resulting cast with the stainless steel master model. The study was motivated by the knowledge that distortions can occur during impression making and the pouring of casts and that this distortion may produce inaccuracies of subsequent restorations, especially long-span castings for implant superstructures. The master model was a stainless steel model with five implant analogs. The impression materials used were impression plaster (Plastogum, Harry J Bosworth), a polyether (Impregum Penta, 3M ESPE), and two polyvinyl siloxane (PVS) materials (Aquasil Monophase and Aquasil putty with light-body wash, Dentsply). Five impressions were made with each impression material and cast in die stone under strictly controlled laboratory conditions. The positions of the implants on the master model, the impression copings, and the implant analogs in the subsequent casts were measured using a coordinate measuring machine that measures within 4 μm of accuracy. Statistical analyses indicated that distortion occurred in all of the impression materials, but inconsistently. The PVS monophase material reproduced the master model most accurately. Although there was no significant distortion between the impressions and the master model or between the impressions and their casts, there were distortions between the master model and the master casts, which highlighted the cumulative effects of the distortions. The polyether material proved to be the most reliable in terms of predictability. The impression plaster displayed cumulative distortion, and the PVS putty with light body showed the least reliability. Some of the distortions observed are of clinical significance and likely to contribute to a lack of passive fit of any superstructure. The inaccuracy of these analog materials and procedures suggested that greater predictability may lie in digital technology.

Evolution of A-Type Macrosegregation in Large Size Steel Ingot After Multistep Forging and Heat Treatment

NASA Astrophysics Data System (ADS)

Loucif, Abdelhalim; Ben Fredj, Emna; Harris, Nathan; Shahriari, Davood; Jahazi, Mohammad; Lapierre-Boire, Louis-Philippe

2018-03-01

A-type macrosegregation refers to the channel chemical heterogeneities that can be formed during solidification in large size steel ingots. In this research, a combination of experiment and simulation was used to study the influence of open die forging parameters on the evolution of A-type macrosegregation patterns during a multistep forging of a 40 metric ton (MT) cast, high-strength steel ingot. Macrosegregation patterns were determined experimentally by macroetch along the longitudinal axis of the forged and heat-treated ingot. Mass spectroscopy, on more than 900 samples, was used to determine the chemical composition map of the entire longitudinal sectioned surface. FORGE NxT 1.1 finite element modeling code was used to predict the effect of forging sequences on the morphology evolution of A-type macrosegregation patterns. For this purpose, grain flow variables were defined and implemented in a large scale finite element modeling code to describe oriented grains and A-type segregation patterns. Examination of the A-type macrosegregation showed four to five parallel continuous channels located nearly symmetrical to the axis of the forged ingot. In some regions, the A-type patterns became curved or obtained a wavy form in contrast to their straight shape in the as-cast state. Mass spectrometry analysis of the main alloying elements (C, Mn, Ni, Cr, Mo, Cu, P, and S) revealed that carbon, manganese, and chromium were the most segregated alloying elements in A-type macrosegregation patterns. The observed differences were analyzed using thermodynamic calculations, which indicated that changes in the chemical composition of the liquid metal can affect the primary solidification mode and the segregation intensity of the alloying elements. Finite element modeling simulation results showed very good agreement with the experimental observations, thereby allowing for the quantification of the influence of temperature and deformation on the evolution of the shape of the macrosegregation channels during the open die forging process.

Evolution of A-Type Macrosegregation in Large Size Steel Ingot After Multistep Forging and Heat Treatment

NASA Astrophysics Data System (ADS)

Loucif, Abdelhalim; Ben Fredj, Emna; Harris, Nathan; Shahriari, Davood; Jahazi, Mohammad; Lapierre-Boire, Louis-Philippe

2018-06-01

A-type macrosegregation refers to the channel chemical heterogeneities that can be formed during solidification in large size steel ingots. In this research, a combination of experiment and simulation was used to study the influence of open die forging parameters on the evolution of A-type macrosegregation patterns during a multistep forging of a 40 metric ton (MT) cast, high-strength steel ingot. Macrosegregation patterns were determined experimentally by macroetch along the longitudinal axis of the forged and heat-treated ingot. Mass spectroscopy, on more than 900 samples, was used to determine the chemical composition map of the entire longitudinal sectioned surface. FORGE NxT 1.1 finite element modeling code was used to predict the effect of forging sequences on the morphology evolution of A-type macrosegregation patterns. For this purpose, grain flow variables were defined and implemented in a large scale finite element modeling code to describe oriented grains and A-type segregation patterns. Examination of the A-type macrosegregation showed four to five parallel continuous channels located nearly symmetrical to the axis of the forged ingot. In some regions, the A-type patterns became curved or obtained a wavy form in contrast to their straight shape in the as-cast state. Mass spectrometry analysis of the main alloying elements (C, Mn, Ni, Cr, Mo, Cu, P, and S) revealed that carbon, manganese, and chromium were the most segregated alloying elements in A-type macrosegregation patterns. The observed differences were analyzed using thermodynamic calculations, which indicated that changes in the chemical composition of the liquid metal can affect the primary solidification mode and the segregation intensity of the alloying elements. Finite element modeling simulation results showed very good agreement with the experimental observations, thereby allowing for the quantification of the influence of temperature and deformation on the evolution of the shape of the macrosegregation channels during the open die forging process.

46 CFR 160.032-1 - Applicable specifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Steel Castings, Carbon, Suitable for Fusion Welding for High-Temperature Service—160.032-3 (b) Copies on... ASTM from the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA...

Phased Array Ultrasonic Sound Field Mapping in Cast Austenitic Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-05-31

This study maps the phased array-generated acoustic sound fields through three types of CASS microstructure in four specimens to quantitatively assess the beam formation effectiveness in these materials.

Method of making metal matrix composites reinforced with ceramic particulates

DOEpatents

Cornie, James A.; Kattamis, Theodoulos; Chambers, Brent V.; Bond, Bruce E.; Varela, Raul H.

1989-01-01

Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys.

Role of copper in precipitation hardening of high-alloy Cr-Ni cast steels

NASA Astrophysics Data System (ADS)

Gajewski, Mirosław

2006-02-01

The mechanism of strengthening with second-phase particles that results from heat treatment, i.e., precipitate hardening, plays an important role in modern alloys. The strengthening effect of such particles can result from their coherence with the matrix, inhibition of dislocation slip, inhibition of grain boundary slip, as well as hampering recovery processes due to dislocation network pinning. The results of investigations into high-alloy Cr-Ni-Cu cast steels precipitate hardened with highly dispersed ɛ phase particles are presented within. The influence of heat treatment on changes in microstructure, mechanical properties, and morphology of fracture surfaces obtained under loading have been analyzed. It has been demonstrated that, with the appropriate selection of heat treatment parameters, it is possible to control the precipitation of the hardening ɛ phase and, thus, to change the final mechanical and functional properties.

Effects of preparation relief and flow channels on seating full coverage castings during cementation.

PubMed

Webb, E L; Murray, H V; Holland, G A; Taylor, D F

1983-06-01

Machined steel dies were used to study the effects of three die modifications on seating full coverage castings during cementation. The die modifications consisted of occlusal channels, occlusal surface relief, and axial channels. Fourteen specimens having one or more forms of die modification were compared with two control specimens having no die modifications. Statistical analysis of the data revealed that the addition of four axial channels to the simulated preparation on the steel die produced a significant reduction in the mean marginal discrepancy during cementation. Occlusal modifications alone failed to produce significant reductions in marginal discrepancies when compared with the control specimens. Occlusal modifications in conjunction with axial channels failed to produce further significant reductions in marginal discrepancies when compared with those reductions observed in specimens having only axial channels.

Method of making metal matrix composites reinforced with ceramic particulates

DOEpatents

Cornie, J.A.; Kattamis, T.; Chambers, B.V.; Bond, B.E.; Varela, R.H.

1989-08-01

Composite materials and methods for making such materials are disclosed in which dispersed ceramic particles are at chemical equilibrium with a base metal matrix, thereby permitting such materials to be remelted and subsequently cast or otherwise processed to form net weight parts and other finished (or semi-finished) articles while maintaining the microstructure and mechanical properties (e.g. wear resistance or hardness) of the original composite. The composite materials of the present invention are composed of ceramic particles in a base metal matrix. The ceramics are preferably carbides of titanium, zirconium, tungsten, molybdenum or other refractory metals. The base metal can be iron, nickel, cobalt, chromium or other high temperature metal and alloys thereof. For ferrous matrices, alloys suitable for use as the base metal include cast iron, carbon steels, stainless steels and iron-based superalloys. 2 figs.

Heat Treatment of Thixo-Formed Hypereutectic X210CrW12 Tool Steel

NASA Astrophysics Data System (ADS)

Rogal, Łukasz; Dutkiewicz, Jan

2012-12-01

Steel is a particularly challenging material to semisolid process because of the high temperatures involved and the potential for surface oxidation. Hot-rolled X210CrW12 tool steel was applied as a feedstock for thixoforming. The samples were heated up to 1525 K (1250 °C) to obtain 30 pct of the liquid phase. They were pressed in the semisolid state into a die preheated up to 473 K (200 °C) using a device based on a high-pressure die casting machine. As a result, a series of main bucket tooth thixo-casts for a mining combine was obtained. The microstructure of the thixo-cast consisted of austenite globular grains (average grain size 46 μm) surrounded by a eutectic mixture (ferrite, austenite, and M7C3 carbides). The average hardness of primary austenite grains was 470 HV0.02 and that of eutectic 551 HV0.02. The X-ray analysis confirmed the presence of 11.8 pct α-Fe, 82.4 pct γ-Fe, and 5.8 pct M7C3 carbides in the thixo-cast samples. Thermal and dilatometric effects were registered in the solid state, and the analysis of curves enabled the determination of characteristic temperatures of heat treatment: 503 K, 598 K, 693 K, 798 K, 828 K, 903 K, and 953 K (230 °C, 325 °C, 420 °C, 525 °C, 555 °C, 630 °C, 680 °C). The thixo-casts were annealed at these temperatures for 2 hours. During annealing in the temperature range 503 K to 693 K (230 °C to 420 °C), the hardness of primary globular grains continuously decreased down to 385HV0.02. The X-ray diffraction showed a slight shift of peaks responsible for the tension release. Moreover, after the treatment at 693 K (420 °C), an additional peak from precipitated carbides was observed in the X-ray diffraction. Thin plates of perlite (average hardness 820 HV0.02) with carbide precipitates appeared at the boundaries of globular grains at 798 K (525 °C). They occupied 17 pct of the grain area. Plates of martensite were found in the center of grains, while the retained austenite was observed among them (average hardness of center grains was 512 HV0.02). A nearly complete decomposition of metastable austenite was achieved after tempering at 828 K (555 °C) due to prevailing lamellar pearlite structure starting at grain boundaries and the martensite located in the center of the grains. The X-ray analysis confirmed the presence of 3.4 pct γ-Fe, 84.6 pct α-Fe, and 12 pct M7C3 carbides. The dilatometric analysis showed that the transformation of metastable austenite into martensite took place during cooling from 828 K (555 °C). The additional annealing at 523 K (250 °C) for 2 hours after heat treatment at 828 K (555 °C) caused the precipitation of carbides from the martensite. After tempering at 903 K (630 °C), the thixo-cast microstructure showed globular grains consisting mainly of thick lamellar perlite of the average hardness 555 HV0.02.

Permanent Mold Casting of JIS-AC4C Aluminum Alloy Using a Low-Temperature Mold

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamagata, Hiroshi; Nikawa, Makoto

2011-01-17

Permanent mold casting using mold temperatures below 200 deg. C was conducted to obtain a high-strength, thin-walled casting. Al-7.36 mass% Si -0.18 Cu- 0.27Mg-0.34Fe alloy JIS-AC4C was cast using a bottom pouring cast plan. The product had a rectangular tube shape (70 mm W x 68 mm D x 180 mm H) with wall thicknesses of 1, 3 and 5 mm. The effect of heat insulation at the melt path was compared when using a sand runner insert and when using a steel runner insert as well as a powder mold release agent. Fine microstructures were observed in the casting.more » The smaller the thickness, the higher the hardness with smaller secondary dendrite arm spacing (SDAS). However, the hardness and the SDAS were unaffected by the mold temperature. It was proposed that the avoidance of the formation of primary {alpha} dendrite at the melt path generates a higher strength casting with adequate mold filling.« less

Novel technologies for the lost foam casting process

NASA Astrophysics Data System (ADS)

Jiang, Wenming; Fan, Zitian

2018-03-01

Lost foam casting (LFC) is a green precision casting process categorized as a near net forming technology. Yet, despite its popularity, it still suffers from some technological problems, such as poor filling ability of the castings, coarse and non-dense microstructure, low mechanical properties for the Al and Mg LFC processes, and defective carburization for the low carbon steel LFC process. These drawbacks restrict the development and widespread application of the LFC process. To solve these problems, the present study developed several novel LFC technologies, namely, LFC technologies under vacuum and low pressure, vibration solidification, and pressure solidification conditions; expendable shell casting technology; and preparation technology of bimetallic castings based on the LFC process. The results showed that the LFC under vacuum and low pressure evidently improved the filling ability and solved the oxidization problem of the alloys, which is suitable for producing complex and thinwall castings. The vibration and pressure solidifications increased the compactness of the castings and refined the microstructure, significantly improving the mechanical properties of the castings. The expendable shell casting technology could solve the pore, carburization, and inclusion defects of the traditional LFC method, obtaining castings with acceptable surface quality. Moreover, the Al/Mg and Al/Al bimetallic castings with acceptable metallurgical bonding were successfully fabricated using the LFC process. These proposed novel LFC technologies can solve the current technological issues and promote the technological progress of the LFC process.

Processing of Advanced Cast Alloys for A-USC Steam Turbine Applications

NASA Astrophysics Data System (ADS)

Jablonski, Paul D.; Hawk, Jeffery A.; Cowen, Christopher J.; Maziasz, Philip J.

2012-02-01

The high-temperature components within conventional supercritical coal-fired power plants are manufactured from ferritic/martensitic steels. To reduce greenhouse-gas emissions, the efficiency of pulverized coal steam power plants must be increased to as high a temperature and pressure as feasible. The proposed steam temperature in the DOE/NETL Advanced Ultra Supercritical power plant is high enough (760°C) that ferritic/martensitic steels will not work for the majority of high-temperature components in the turbine or for pipes and tubes in the boiler due to temperature limitations of this class of materials. Thus, Ni-based superalloys are being considered for many of these components. Off-the-shelf forged nickel alloys have shown good promise at these temperatures, but further improvements can be made through experimentation within the nominal chemistry range as well as through thermomechanical processing and subsequent heat treatment. However, cast nickel-based superalloys, which possess high strength, creep resistance, and weldability, are typically not available, particularly those with good ductility and toughness that are weldable in thick sections. To address those issues related to thick casting for turbine casings, for example, cast analogs of selected wrought nickel-based superalloys such as alloy 263, Haynes 282, and Nimonic 105 have been produced. Alloy design criteria, melt processing experiences, and heat treatment are discussed with respect to the as-processed and heat-treated microstructures and selected mechanical properties. The discussion concludes with the prospects for full-scale development of a thick section casting for a steam turbine valve chest or rotor casing.

Alloy Shrinkage factors for the investment casting of 17-4PH stainless steel parts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sabau, Adrian S; Porter, Wallace D

2008-01-01

In this study, the alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. Dimensions of the die tooling, wax pattern, and casting were measured using a Coordinate Measurement Machine. For all the properties, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. A comparison between the predicted material property data measured property data is made. It was found that most material properties weremore » accurately predicted over the most of the temperature range of the process. Several assumptions were made in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted at heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed different evolution at heating and cooling. Thus, one generic simulation were performed with thermal expansion obtained at heating and another one with thermal expansion obtained at cooling. The alloy dimensions were obtained from numerical simulation results of solidification, heat transfer, and deformation phenomena. As compared with experimental results, the numerical simulation results for the shrinkage factors were slightly over-predicted.« less

Alloy Shrinkage Factors for the Investment Casting of 17-4PH Stainless Steel Parts

NASA Astrophysics Data System (ADS)

Sabau, Adrian S.; Porter, Wallace D.

2008-04-01

In this study, alloy shrinkage factors were obtained for the investment casting of 17-4PH stainless steel parts. For the investment casting process, unfilled wax and fused silica with a zircon prime coat were used for patterns and shell molds, respectively. The dimensions of the die tooling, wax pattern, and casting were measured using a coordinate measurement machine (CMM). For all the properties, the experimental data available in the literature did not cover the entire temperature range necessary for process simulation. A comparison between the predicted material property data and measured property data is made. It was found that most material properties were accurately predicted over most of the temperature range of the process. Several assumptions were made, in order to obtain a complete set of mechanical property data at high temperatures. Thermal expansion measurements for the 17-4PH alloy were conducted during heating and cooling. As a function of temperature, the thermal expansion for both the alloy and shell mold materials showed a different evolution on heating and cooling. Thus, one generic simulation was performed with thermal expansion obtained on heating, and another one was performed with thermal expansion obtained on cooling. The alloy dimensions were obtained from the numerical simulation results of the solidification, heat transfer, and deformation phenomena. As compared with experimental results, the numerical simulation results for the shrinkage factors were slightly overpredicted.

Computational Design of a Novel Medium-Carbon, Low-Alloy Steel Microalloyed with Niobium

NASA Astrophysics Data System (ADS)

Javaheri, Vahid; Nyyssönen, Tuomo; Grande, Bjørnar; Porter, David

2018-04-01

The design of a new steel with specific properties is always challenging owing to the complex interactions of many variables. In this work, this challenge is dealt with by combining metallurgical principles with computational thermodynamics and kinetics to design a novel steel composition suitable for thermomechanical processing and induction heat treatment to achieve a hardness level in excess of 600 HV with the potential for good fracture toughness. CALPHAD-based packages for the thermodynamics and kinetics of phase transformations and diffusion, namely Thermo-Calc® and JMatPro®, have been combined with an interdendritic segregation tool (IDS) to optimize the contents of chromium, molybdenum and niobium in a proposed medium-carbon low-manganese steel composition. Important factors taken into account in the modeling and optimization were hardenability and as-quenched hardness, grain refinement and alloying cost. For further investigations and verification, the designed composition, i.e., in wt.% 0.40C, 0.20Si, 0.25Mn, 0.90Cr, 0.50Mo, was cast with two nominal levels of Nb: 0 and 0.012 wt.%. The results showed that an addition of Nb decreases the austenite grain size during casting and after slab reheating prior to hot rolling. Validation experiments showed that the predicted properties, i.e., hardness, hardenability and level of segregation, for the designed composition were realistic. It is also demonstrated that the applied procedure could be useful in reducing the number of experiments required for developing compositions for other new steels.

Heat-Resistant Alloys for Ordnance Materiel and Aircraft and Naval Engine Parts (N-102): Part 1 - Heat Resistant Alloys of the 21%Cr:9%Ni Type

DTIC Science & Technology

1945-06-29

10.555Ni Alloy 22 Sigma and Ferrite In 22.3#r:7.7*Ni Alloy 23 Ferrite Mosaic In 22.3#r:7.7#Ni Alloy 24 Precipitated Carbides In 21.2*Cr:8.7*Ni... ferritic steels and heat resistant cast irons are widely applied. Where plasticity is essential,steels must be used. The irons exhibit some...ductility above 900°F, but they are seldom able to survive sudden thermal or mechanical stresses that exceed their elastic strength. Ferritic steels, of

Size and Velocity Characteristics of Droplets Generated by Thin Steel Slab Continuous Casting Secondary Cooling Air-Mist Nozzles

NASA Astrophysics Data System (ADS)

Minchaca M, J. I.; Castillejos E, A. H.; Acosta G, F. A.

2011-06-01

Direct spray impingement of high temperature surfaces, 1473 K to 973 K (1200 °C to 700 °C), plays a critical role in the secondary cooling of continuously cast thin steel slabs. It is known that the spray parameters affecting the local heat flux are the water impact flux w as well as the droplet velocity and size. However, few works have been done to characterize the last two parameters in the case of dense mists ( i.e., mists with w in the range of 2 to 90 L/m2s). This makes it difficult to rationalize how the nozzle type and its operating conditions must be selected to control the cooling process. In the present study, particle/droplet image analysis was used to determine the droplet size and velocity distributions simultaneously at various locations along the major axis of the mist cross section at a distance where the steel strand would stand. The measurements were carried out at room temperature for two standard commercial air-assisted nozzles of fan-discharge type operating over a broad range of conditions of practical interest. To achieve statistically meaningful samples, at least 6000 drops were analyzed at each location. Measuring the droplet size revealed that the number and volume frequency distributions were fitted satisfactorily by the respective log-normal and Nukiyama-Tanasawa distributions. The correlation of the parameters of the distribution functions with the water- and air-nozzle pressures allowed for reasonable estimation of the mean values of the size of the droplets generated. The ensemble of measurements across the mist axis showed that the relationship between the droplet velocity and the diameter exhibited a weak positive correlation. Additionally, increasing the water flow rate at constant air pressure caused a decrease in the proportion of the water volume made of finer droplets, whereas the volume proportion of faster droplets augmented until the water flow reached a certain value, after which it decreased. Diminishing the air-to-water flow rates ratio, particularly below 10, resulted in mists of bigger and slower droplets with low impinging Weber numbers. However, increasing the air pressure maintaining a constant water flow rate caused a greater proportion of finer and faster drops with Weber numbers greater than 80, which suggests an increased probability of wet drop contact with a hot surface that would intensify heat extraction.

46 CFR 162.018-3 - Materials.

Code of Federal Regulations, 2013 CFR

2013-10-01

... resistant material. Seats and disks of cast iron or malleable iron shall not be used. Springs shall be of best quality spring steel consistent with the design of the valve and the service requirement. [CGFR 52...

46 CFR 162.018-3 - Materials.

Code of Federal Regulations, 2012 CFR

2012-10-01

... resistant material. Seats and disks of cast iron or malleable iron shall not be used. Springs shall be of best quality spring steel consistent with the design of the valve and the service requirement. [CGFR 52...

46 CFR 162.018-3 - Materials.

Code of Federal Regulations, 2014 CFR

2014-10-01

... resistant material. Seats and disks of cast iron or malleable iron shall not be used. Springs shall be of best quality spring steel consistent with the design of the valve and the service requirement. [CGFR 52...

Modelling the strength of an aluminium-steel nailed joint

NASA Astrophysics Data System (ADS)

Goldspiegel, Fabien; Mocellin, Katia; Michel, Philippe

2018-05-01

For multi-material applications in automotive industry, a cast aluminium (upper layer) and dual-phase steel (lower layer) superposition joined with High-Speed Nailing process is investigated through an experimental vs numerical framework. Using FORGE® finite-element software, results from joining simulations have been inserted into models in charge of nailed-joint mechanical testings. Numerical Shear and Cross-tensile tests are compared to experimental ones to discuss discrepancy and possible improvements.

Pitting corrosion resistant austenite stainless steel

DOEpatents

van Rooyen, D.; Bandy, R.

A pitting corrosion resistant austenite stainless steel comprises 17 to 28 wt. % chromium, 15 to 26 wt. % nickel, 5 to 8 wt. % molybdenum, and 0.3 to 0.5 wt. % nitrogen, the balance being iron, unavoidable impurities, minor additions made in the normal course of melting and casting alloys of this type, and may optionally include up to 10 wt. % of manganese, up to 5 wt. % of silicon, and up to 0.08 wt. % of carbon.

Mineral resource of the month: molybdenum

USGS Publications Warehouse

Magyar, Michael J.

2004-01-01

Molybdenum is a metallic element that is most frequently used in alloy and stainless steels, which together represent the single largest market for molybdenum. Molybdenum has also proven invaluable in carbon steel, cast iron and superalloys. Its alloying versatility is unmatched because its addition enhances material performance under high-stress conditions in expanded temperature ranges and in highly corrosive environments. The metal is also used in catalysts, other chemicals, lubricants and many other applications.

Determination of the ductile-brittle transition temperature from the microplastic-strain rate

NASA Astrophysics Data System (ADS)

Andreev, A. K.; Solntsev, Yu. P.

2008-04-01

The possibility of the determination of the tendency of cast and deformed steels to brittle fracture using the temperature dependence of the small-plastic-strain rate is studied. The temperature corresponding to the maximum in this curve is found to indicate an abrupt decrease in the steel plasticity, which makes it possible to interpret it as the ductile-brittle transition temperature depending only on the structure of a material.

Literature Survey on Weld-Metal Cracking

DTIC Science & Technology

1952-08-01

quench cracking in cast steel. A statistical investigation was made into the causes of quench cracking in low-alloy-steel gun tubes (FlZ). A definite...decreased with increased pouring temperature, finishing temperature, and forging reduction. Spretnak and Wells(F2O) also made a statistical analysis of...per cent to avoid hot cracks and fissures. Lee(I20) made a statistical study of the bead-cracking susceptibility of weld metal deposited with Type 307

Energy and Process Optimization and Benchmarking of Army Industrial Processes

DTIC Science & Technology

2006-09-01

casting is a metal part formed by pouring molten iron, steel, aluminum, zinc , titanium, magnesium, copper, brass, bronze or cobalt, in nearly all...blanketing techniques. The loss of high-priced alloys is also mini- mized, while slag or dross rates are cut in half to help decrease disposal costs...fabricated of iron and steel; hot dip coating such items with aluminum, lead, or zinc ; retin- ning cans and utensils; (3) engraving, chasing and

A comprehensive review on cold work of AISI D2 tool steel

NASA Astrophysics Data System (ADS)

Abdul Rahim, Mohd Aidil Shah bin; Minhat, Mohamad bin; Hussein, Nur Izan Syahriah Binti; Salleh, Mohd Shukor bin

2017-11-01

As a common material in mould and die application, AISI D2 cold work tool steel has proven to be a promising chosen material in the industries. However, challenges remain in using AISI D2 through a modified version with a considerable progress having been made in recent years. This paper provides a critical review of the original as-cast AISI D2 cold work tool steel up to the modified version. The main purpose is to develop an understanding of current modified tool steel trend; the machinability of AISI D2 (drilling, milling, turning, grinding and EDM/WEDM; and the microstructure evolution and mechanical properties of these cold work tool steels due to the presence of alloy materials in the steel matrix. The doping of rare earth alloy element, new steel fabrication processes, significant process parameter in machinability and surface treatment shows that there have been few empirical investigations into these cold work tool steel alloys. This study has discovered that cold work tool steel will remain to be explored in order to survive in the steel industries.

Effect of Solutes on Grain Refinement of As-Cast Fe-4Si Alloy

NASA Astrophysics Data System (ADS)

Li, Ming; Li, Jian-Min; Zheng, Qing; Wang, Geoff; Zhang, Ming-Xing

2018-06-01

Grain size is one of the key microstructural factors that control the mechanical properties of steels. The present work aims to extend the theories of grain refinement which were established for cast light alloys to steel systems. Using a designed Fe-4 wt pct Si alloy (all-ferrite structure during whole solidification process), the solute effect on grain refinement/grain coarsening in ferritic systems was comprehensively investigated. Experimental results showed that boron (B), which is associated with the highest Q value (growth restriction factor) in ferrite, significantly refined the as-cast structure of the Fe-4 wt pct Si alloy. Cu and Mo with low Q values had no effect on grain refinement. However, although Y and Zr have relatively high Q values, addition of these two solutes led to grain coarsening in the Fe-4Si alloy. Understanding the results in regards to the growth restriction factor and the driving force for the solidification led to the conclusion that in addition to the grain growth restriction effect, the changes of thermodynamic driving force for solidification due to the solute addition also played a key role in grain refinement in ferritic alloys.

Effect of Solutes on Grain Refinement of As-Cast Fe-4Si Alloy

NASA Astrophysics Data System (ADS)

Li, Ming; Li, Jian-Min; Zheng, Qing; Wang, Geoff; Zhang, Ming-Xing

2018-03-01

Grain size is one of the key microstructural factors that control the mechanical properties of steels. The present work aims to extend the theories of grain refinement which were established for cast light alloys to steel systems. Using a designed Fe-4 wt pct Si alloy (all-ferrite structure during whole solidification process), the solute effect on grain refinement/grain coarsening in ferritic systems was comprehensively investigated. Experimental results showed that boron (B), which is associated with the highest Q value (growth restriction factor) in ferrite, significantly refined the as-cast structure of the Fe-4 wt pct Si alloy. Cu and Mo with low Q values had no effect on grain refinement. However, although Y and Zr have relatively high Q values, addition of these two solutes led to grain coarsening in the Fe-4Si alloy. Understanding the results in regards to the growth restriction factor and the driving force for the solidification led to the conclusion that in addition to the grain growth restriction effect, the changes of thermodynamic driving force for solidification due to the solute addition also played a key role in grain refinement in ferritic alloys.

Effect of Starting As-cast Structure on the Microstructure-Texture Evolution During Subsequent Processing and Finally Ridging Behavior of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Modak, Pranabananda; Patra, Sudipta; Mitra, Rahul; Chakrabarti, Debalay

2018-03-01

Effect of the initial as-cast structure on the microstructure-texture evolution during thermomechanical processing of 409L grade ferritic stainless steel was studied. Samples from the regions of cast slab having `columnar,' `equiaxed,' and a mixture of `columnar' and `equiaxed' grains were subjected to two different processing schedules: one with intermediate hot-band annealing before cold-rolling followed by final annealing, and another without any hot-band annealing. EBSD study reveals that large columnar crystals with cube orientation are very difficult to deform and recrystallize uniformly. Resultant variations in ferrite grain structure and retention of cube-textured band in cold-rolled and annealed sheet contribute to ridging behavior during stretch forming. Initial equiaxed grain structure is certainly beneficial to reduce or even eliminate ridging defect by producing uniform ferrite grain structure, free from any texture banding. Application of hot-band annealing treatment is also advantageous as it can maximize the evolution of beneficial gamma-fiber texture and eliminate the ridging defect in case of completely `equiaxed' starting structure. Such treatment reduces the severity of ridging even if the initial structure contains typically mixed `columnar-equiaxed' grains.

Effect of Starting As-cast Structure on the Microstructure-Texture Evolution During Subsequent Processing and Finally Ridging Behavior of Ferritic Stainless Steel

NASA Astrophysics Data System (ADS)

Modak, Pranabananda; Patra, Sudipta; Mitra, Rahul; Chakrabarti, Debalay

2018-06-01

Effect of the initial as-cast structure on the microstructure-texture evolution during thermomechanical processing of 409L grade ferritic stainless steel was studied. Samples from the regions of cast slab having `columnar,' `equiaxed,' and a mixture of `columnar' and `equiaxed' grains were subjected to two different processing schedules: one with intermediate hot-band annealing before cold-rolling followed by final annealing, and another without any hot-band annealing. EBSD study reveals that large columnar crystals with cube orientation are very difficult to deform and recrystallize uniformly. Resultant variations in ferrite grain structure and retention of cube-textured band in cold-rolled and annealed sheet contribute to ridging behavior during stretch forming. Initial equiaxed grain structure is certainly beneficial to reduce or even eliminate ridging defect by producing uniform ferrite grain structure, free from any texture banding. Application of hot-band annealing treatment is also advantageous as it can maximize the evolution of beneficial gamma-fiber texture and eliminate the ridging defect in case of completely `equiaxed' starting structure. Such treatment reduces the severity of ridging even if the initial structure contains typically mixed `columnar-equiaxed' grains.

Investigation on the Effect of Mold Constraints and Cooling Rate on Residual Stress During the Sand-Casting Process of 1086 Steel by Employing a Thermomechanical Model

NASA Astrophysics Data System (ADS)

Baghani, Amir; Davami, Parviz; Varahram, Naser; Shabani, Mohsen Ostad

2014-06-01

In this study, the effects of mold constraints and cooling rate on residual stress were analyzed during the shaped casting process. For this purpose, an H-shaped sample was designed in which the contraction of its middle portion is highly restricted by the mold during the cooling process. The effects of an increasing cooling rate combined with mold constraints were analyzed by reducing the thickness of the middle portion in the second sample. A three-dimensional coupled temperature-displacement analysis was performed in finite-element code ABAQUS to simulate residual stress distribution, and then numerical results were verified by the hole-drilling strain-gauge method. It was concluded that the mold constraints have a greater effect on the values of residual stress than the cooling rate (thin section) in steel sand casting. Increasing the cooling rate would increase the amount of residual stress, only in the presence of mold constraints. It is also suggested that employing the elastic-plastic stress model for the sand mold will satisfy the experimental results and avoid exaggerated values of residual stress in simulation.

High pressure die casting of Fe-based metallic glass.

PubMed

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-10-11

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

High pressure die casting of Fe-based metallic glass

NASA Astrophysics Data System (ADS)

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-10-01

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications.

High pressure die casting of Fe-based metallic glass

PubMed Central

Ramasamy, Parthiban; Szabo, Attila; Borzel, Stefan; Eckert, Jürgen; Stoica, Mihai; Bárdos, András

2016-01-01

Soft ferromagnetic Fe-based bulk metallic glass key-shaped specimens with a maximum and minimum width of 25.4 and 5 mm, respectively, were successfully produced using a high pressure die casting (HPDC) method, The influence of die material, alloy temperature and flow rate on the microstructure, thermal stability and soft ferromagnetic properties has been studied. The results suggest that a steel die in which the molten metal flows at low rate and high temperature can be used to produce completely glassy samples. This can be attributed to the laminar filling of the mold and to a lower heat transfer coefficient, which avoids the skin effect in the steel mold. In addition, magnetic measurements reveal that the amorphous structure of the material is maintained throughout the key-shaped samples. Although it is difficult to control the flow and cooling rate of the molten metal in the corners of the key due to different cross sections, this can be overcome by proper tool geometry. The present results confirm that HPDC is a suitable method for the casting of Fe-based bulk glassy alloys even with complex geometries for a broad range of applications. PMID:27725780

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 31 2012-07-01 2012-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 31 2013-07-01 2013-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 30 2014-07-01 2014-07-01 false Applicability; description of the zinc casting subcategory. 464.40 Section 464.40 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS (CONTINUED) METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40...

Dimensional accuracy of resultant casts made by a monophase, one-step and two-step, and a novel two-step putty/light-body impression technique: an in vitro study.

PubMed

Caputi, Sergio; Varvara, Giuseppe

2008-04-01

Dimensional accuracy when making impressions is crucial to the quality of fixed prosthodontic treatment, and the impression technique is a critical factor affecting this accuracy. The purpose of this in vitro study was to compare the dimensional accuracy of a monophase, 1- and 2-step putty/light-body, and a novel 2-step injection impression technique. A stainless steel model with 2 abutment preparations was fabricated, and impressions were made 15 times with each technique. All impressions were made with an addition-reaction silicone impression material (Aquasil) and a stock perforated metal tray. The monophase impressions were made with regular body material. The 1-step putty/light-body impressions were made with simultaneous use of putty and light-body materials. The 2-step putty/light-body impressions were made with 2-mm-thick resin-prefabricated copings. The 2-step injection impressions were made with simultaneous use of putty and light-body materials. In this injection technique, after removing the preliminary impression, a hole was made through the polymerized material at each abutment edge, to coincide with holes present in the stock trays. Extra-light-body material was then added to the preliminary impression and further injected through the hole after reinsertion of the preliminary impression on the stainless steel model. The accuracy of the 4 different impression techniques was assessed by measuring 3 dimensions (intra- and interabutment) (5-mum accuracy) on stone casts poured from the impressions of the stainless steel model. The data were analyzed by 1-way ANOVA and Student-Newman-Keuls test (alpha=.05). The stone dies obtained with all the techniques had significantly larger dimensions as compared to those of the stainless steel model (P<.01). The order for highest to lowest deviation from the stainless steel model was: monophase, 1-step putty/light body, 2-step putty/light body, and 2-step injection. Significant differences among all of the groups for both absolute dimensions of the stone dies, and their percent deviations from the stainless steel model (P<.01), were noted. The 2-step putty/light-body and 2-step injection techniques were the most dimensionally accurate impression methods in terms of resultant casts.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, T.; Shimizu, S.; Ogata, Y.

For the primary coolant piping of PWRs in Japan, cast duplex stainless steel which is excellent in terms of strength, corrosion resistance, and weldability has conventionally been used. The cast duplex stainless steel contains the ferrite phase in the austenite matrix and thermal aging after long term service is known to change its material characteristics. It is considered appropriate to apply the methodology of elastic plastic fracture mechanics for an evaluation of the integrity of the primary coolant piping after thermal aging. Therefore we evaluated the integrity of the primary coolant piping for an initial PWR plant in Japan bymore » means of elastic plastic fracture mechanics. The evaluation results show that the crack will not grow into an unstable fracture and the integrity of the piping will be secured, even when such through wall crack length is assumed to equal the fatigue crack growth length for a service period of up to 60 years.« less

Development of a Thin-Wall Magnesium side door Inner Panel for Automobiles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jekl, J.; Auld, J.; Sweet, C.

Cast magnesium side door inner panels can provide a good combination of weight, functional, manufacturing and economical requirements. However, several challenges exist including casting technology for thin-wall part design, multi-material incompatibility and relatively low strength vs steel. A project has been initiated, supported by the US Department of Energy, to design and develop a lightweight frame-under-glass door having a thin-wall, full die-cast, magnesium inner panel. This development project is the first of its kind within North America. Phase I of the project is now complete and the 2.0mm magnesium design, through casting process enablers, has met or exceeded all stiffnessmore » requirements, with significant mass reduction and part consolidation. In addition, a corrosion mitigation strategy has been established using industry-accepted galvanic isolation methods and coating technologies.« less

Friction and the development of hard alloy surface microstructures during wear

NASA Astrophysics Data System (ADS)

Gnyusov, S. F.; Tarassov, S. Yu.

1997-12-01

Investigations of wear in sliding friction of WC-Hadfield steel hard alloy against cast tool steel have been carried out in a broad range of velocities and pressure values. Structural and phase composition variations have been revealed. Friction-affected zone was found to be 450 µm in depth. Structural γ → α, γ → transformation regions are located within 100 μm of the surface. These transformations contributed to the total solid solution deformation hardening.

Crack growth rates and fracture toughness of irradiated austenitic stainless steels in BWR environments.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chopra, O. K.; Shack, W. J.

2008-01-21

In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as {approx} 2x 10{sup 21} n/cm{sup 2} (E > 1more » MeV) ({approx} 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking conditions were determined. A superposition model was used to represent the cyclic CGRs of austenitic SSs. The effects of neutron irradiation on the fracture toughness of these steels, as well as the effects of material and irradiation conditions and test temperature, have been evaluated. A fracture toughness trend curve that bounds the existing data has been defined. The synergistic effects of thermal and radiation embrittlement of cast austenitic SS internal components have also been evaluated.« less

Investigation on the cold rolling and structuring of cold sprayed copper-coated steel sheets

NASA Astrophysics Data System (ADS)

Bobzin, K.; Öte, M.; Wiesner, S.; Gerdt, L.; Senge, S.; Hirt, G.

2017-03-01

A current driving force of research is lightweight design. One of the approaches to reduce the weight of a component without causing an overall stiffness decrease is the use of multi-material components. One of the main challenges of this approach is the low bonding strength between different materials. Focusing on steel-aluminum multi-material components, thermally sprayed copper coatings can come into use as a bonding agent between steel sheets and high pressure die cast aluminum to improve the bonding strength. This paper presents a combination of cold gas spraying of copper coatings and their subsequent structuring by rolling as surface pretreatment method of the steel inserts. Therefore, flat rolling experiments are performed with samples in “as sprayed” and heat treated conditions to determine the influence of the rolling process on the bond strength and the formability of the coating. Furthermore, the influence of the rolling on the roughness and the hardness of the coating was examined. In the next step, the coated surface was structured, to create a surface topology suited for a form closure connection in a subsequent high-pressure die casting process. No cracks were observed after the cold rolling process with a thickness reduction of up to ε = 14 % for heat treated samples. Structuring of heat treated samples could be realized without delamination and cracking.

Progress in thermomechanical control of steel plates and their commercialization

PubMed Central

Nishioka, Kiyoshi; Ichikawa, Kazutoshi

2012-01-01

The water-cooled thermomechanical control process (TMCP) is a technology for improving the strength and toughness of water-cooled steel plates, while allowing control of the microstructure, phase transformation and rolling. This review describes metallurgical aspects of the microalloying of steel, such as niobium addition, and discusses advantages of TMCP, for example, in terms of weldability, which is reduced upon alloying. Other covered topics include the development of equipment, distortions in steel plates, peripheral technologies such as steel making and casting, and theoretical modeling, as well as the history of property control in steel plate production and some early TMCP technologies. We provide some of the latest examples of applications of TMCP steel in various industries such as shipbuilding, offshore structures, building construction, bridges, pipelines, penstocks and cryogenic tanks. This review also introduces high heat-affected-zone toughness technologies, wherein the microstructure of steel is improved by the addition of fine particles of magnesium-containing sulfides and magnesium- or calcium-containing oxides. We demonstrate that thanks to ongoing developments TMCP has the potential to meet the ever-increasing demands of steel plates. PMID:27877477

Progress in thermomechanical control of steel plates and their commercialization

NASA Astrophysics Data System (ADS)

Nishioka, Kiyoshi; Ichikawa, Kazutoshi

2012-04-01

The water-cooled thermomechanical control process (TMCP) is a technology for improving the strength and toughness of water-cooled steel plates, while allowing control of the microstructure, phase transformation and rolling. This review describes metallurgical aspects of the microalloying of steel, such as niobium addition, and discusses advantages of TMCP, for example, in terms of weldability, which is reduced upon alloying. Other covered topics include the development of equipment, distortions in steel plates, peripheral technologies such as steel making and casting, and theoretical modeling, as well as the history of property control in steel plate production and some early TMCP technologies. We provide some of the latest examples of applications of TMCP steel in various industries such as shipbuilding, offshore structures, building construction, bridges, pipelines, penstocks and cryogenic tanks. This review also introduces high heat-affected-zone toughness technologies, wherein the microstructure of steel is improved by the addition of fine particles of magnesium-containing sulfides and magnesium- or calcium-containing oxides. We demonstrate that thanks to ongoing developments TMCP has the potential to meet the ever-increasing demands of steel plates.

Study of hot cracking potential in a 6-ton steel ingot casting

NASA Astrophysics Data System (ADS)

Yang, Jing'an; Liu, Baicheng; Shen, Houfa

2018-04-01

A new hot cracking potential (HCP) criterion, for the appearance of hot tearing in steel ingot castings, is proposed. The maximum value of the first principal stress, divided by the dynamic yield strength in the brittle temperature range (BTR), was used to identify the HCP. Experiments were carried out on a 6-ton P91 steel ingot in which severe hot tearing was detected in the upper centerline. Another ingot, with a better heat preservation riser, and without hot tearing, was used for comparison. Samples were obtained from the area of the ingot body with hot tearing, and their morphologies were inspected by a X-ray high energy industrial computed tomography. The carbon and sulfur distributions around the hot tearing were characterized by an infrared spectrometry carbon and sulfur analyzer. High temperature mechanical properties were obtained by a Gleeble thermal simulation machine, under different strain rates. Then, thermo-mechanical simulations using an elasto-viscoplastic finite-element model were conducted to analyze the stress and strain evolution during ingot solidification. The results showed that the hot tearing area, which was rich in both carbon and sulfur, was under excessive tensile stress in the BTR, bearing the highest HCP.

Failure Mechanisms of the Protective Coatings for the Hot Stamping Applications

NASA Astrophysics Data System (ADS)

Zhao, Chen

In the present study, four different nitriding techniques were carried on the ductile irons NAAMS-D6510 and cast steels NAAMS-S0050A, which are widely used stamping die materials; duplex treatments (PVD CrN coating+nitriding) were carried on H13 steels, which are common inserts for the hot stamping dies. Inclined impact-sliding wear tests were performed on the nitriding cases under simulated stamping conditions. Surface profilometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were used to investigate the wear and failure mechanisms of the protective coatings. It was found that the nitrided ductile iron samples performed better than the nitrided cast steel specimens. High temperature inclined impact-sliding wear tests were carried out on the CrN coatings. It was found that the coating performed better at elevated temperature. XPS analysis indicated the top surface layer (about 3-4nm) of the coating was oxidized at 400 °C and formed a Cr2O3 protective film. The in-situ formation of the thin Cr2O3 protective layer likely led to the change of wear mechanisms from severe adhesive failure to mild abrasive wear.

Research notes : keeping steel bars anchored in cracked girders.

DOT National Transportation Integrated Search

2011-01-01

Researchers at Oregon State University fabricated large-size reinforced concrete beams each with an intentional crack made by positioning a plastic sheet in the formwork when the beams were cast. By maintaining control over crack location, crack angl...

49 CFR 173.188 - White or yellow phosphorus.

Code of Federal Regulations, 2013 CFR

2013-10-01

...) Inner water-tight metal cans containing not over 0.5 kg (1 pound) of phosphorus with screw-top closures... each. (b) When dry, it must be cast solid and shipped in packagings as follows: (1) Steel, aluminum or...

49 CFR 173.188 - White or yellow phosphorus.

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Inner water-tight metal cans containing not over 0.5 kg (1 pound) of phosphorus with screw-top closures... each. (b) When dry, it must be cast solid and shipped in packagings as follows: (1) Steel, aluminum or...

GENERAL VIEW FROM THE EAST SHOWING THE 'PIG MACHINE', THE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

GENERAL VIEW FROM THE EAST SHOWING THE 'PIG MACHINE', THE #1 CASTING SHED AND THE #1 FURNACE IN THE FOREGROUND. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

Energy Saving Melting and Revert Reduction Technology: Improved Die Casting Process to Preserve the Life of the Inserts

DOE Office of Scientific and Technical Information (OSTI.GOV)

David Schwam, PI; Xuejun Zhu, Sr. Research Associate

2012-09-30

The goal of this project was to study the combined effects of die design, proper internal cooling and efficient die lubricants on die life. The project targeted improvements in die casting insert life by: Optomized Die Design for Reduced Surface Temperature: The life of die casting dies is significantly shorter when the die is exposed to elevated temperature for significant periods of time. Any die operated under conditions leading to surface temperature in excess of 1050oF undergoes structural changes that reduce its strength. Optimized die design can improve die life significantly. This improvement can be accomplished by means of coolingmore » lines, baffles and bubblers in the die. A key objective of the project was to establish criteria for the minimal distance of the cooling lines from the surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. The Uddeholm Dievar steel evaluated in this program showed superior resistance to thermal fatigue resistance. Based on the experimental evidence, cooling lines could be placed as close as 0.5" from the surface. Die Life Extension by Optimized Die Lubrication: The life of die casting dies is affected by additions made to its surface with the proper lubricants. These lubricants will protect the surface from the considerable temperature peaks that occur when the molten melt enters the die. Dies will reach a significantly higher temperature without this lubricant being applied. The amount and type of the lubricant are critical variables in the die casting process. However, these lubricants must not corrode the die surface. This effort was supported with alloys and machining by BohlerUddeholm, Dunn Steel, HH Stark and Rex Buckeye. In plant testing and evaluation was conducted as in-kind cost share at St. Clair Die Casting. Chem- Trend participated in the program with die lubricants and technical support. Experiments conducted with these lubricants demonstrated good protection of the substrate steel. Graphite and boron nitride used as benchmarks are capable of completely eliminating soldering and washout. However, because of cost and environmental considerations these materials are not widely used in industry. The best water-based die lubricants evaluated in this program were capable of providing similar protection from soldering and washout. In addition to improved part quality and higher production rates, improving die casting processes to preserve the life of the inserts will result in energy savings and a reduction in environmental wastes. Improving die life by means of optimized cooling line placement, baffles and bubblers in the die will allow for reduced die temperatures during processing, saving energy associated with production. The utilization of optimized die lubricants will also reduce heat requirements in addition to reducing waste associated with soldering and washout. This new technology was predicted to result in an average energy savings of 1.1 trillion BTU's/year over a 10 year period. Current (2012) annual energy saving estimates, based on commercial introduction in 2010, a market penetration of 70% by 2020 is 1.26 trillion BTU's/year. Along with these energy savings, reduction of scrap and improvement in casting yield will result in a reduction of the environmental emissions associated with the melting and pouring of the metal which will be saved as a result of this technology. The average annual estimate of CO2 reduction per year through 2020 is 0.025 Million Metric Tons of Carbon Equivalent (MM TCE).« less

Development of a Modulated-Microstructure Heat Treatable Steel

DTIC Science & Technology

1975-07-10

IV. Heat Treatment V. Results and Discussion V. 1 Properties of the Soft Layer Alloy, PS4 V. 2 Properties of High Speed Steel (REX 71) V. 3...the High Strength System. Fig. 6 Hardness of Tempered PS4 Alloy. Cast alloy hardened by austenitizing, at 2175^ quenched, and reheating three times...at 1000oF and then cooling in liquid nitrogen to form martensite. Fig. 7A Metallographic Section Through Impact Fracture of PS4 Tempered at 300oF

Evolution of Inclusions During the 1473 K (1200 °C) Heating Process of EH36 Shipbuilding Steel

NASA Astrophysics Data System (ADS)

Wang, Qiyu; Zou, Xiaodong; Matsuura, Hiroyuki; Wang, Cong

2018-02-01

Evolution behaviors of inclusions of EH36 shipbuilding steel during 1473 K (1200 °C) heating have been studied in conjunction with ex situ scanning electron microscope (SEM) examination and in situ confocal scanning laser microscopy (CSLM) observations. It has been found that Al-Ca-O-S complex inclusions dominate the particles in the cast billet. However, TiN inclusions are profusely populated after heating. Moreover, possible strategies governing austenite growth are offered here.

High Strength and Wear Resistant Aluminum Alloy for High Temperature Applications

NASA Technical Reports Server (NTRS)

Lee, Jonathan A.; Munafo, Paul M. (Technical Monitor)

2002-01-01

In this paper, a new high strength and wear resistant aluminum cast alloy invented by NASA-MSFC for high temperature applications will be presented. Developed to meet U.S. automotive legislation requiring low-exhaust emission, the novel NASA 398 aluminum-silicon alloy offers dramatic improvement in tensile and fatigue strengths at elevated temperatures (500 F-800 F), enabling new pistons to utilize less material, which can lead to reducing part weight and cost as well as improving performance. NASA 398 alloy also offers greater wear resistance, surface hardness, dimensional stability, and lower thermal expansion compared to conventional aluminum alloys for several commercial and automotive applications. The new alloy can be produced economically using permanent steel molds from conventional gravity casting or sand casting. The technology was developed to stimulate the development of commercial aluminum casting products from NASA-developed technology by offering companies the opportunity to license this technology.

Crystallography and Morphology of MC Carbides in Niobium-Titanium Modified As-Cast HP Alloys

NASA Astrophysics Data System (ADS)

Buchanan, Karl G.; Kral, Milo V.; Bishop, Catherine M.

2014-07-01

The microstructures of two as-cast heats of HP alloy stainless steels modified with niobium and titanium were examined with particular attention paid to the interdendritic niobium-titanium-rich carbides formed during solidification of these alloys. Generally, these precipitates obtain a blocky morphology in the as-cast condition. However, the (NbTi)C precipitates may obtain a nodular morphology. To provide further insight to the origin of the two different morphologies obtained by the (NbTi)C precipitates in the HP-NbTi alloy, the microstructure and crystallography of each have been studied in detail using scanning electron microscopy, transmission electron microscopy, various electron diffraction methods (EBSD, SAD, and CBED), and energy-dispersive X-ray spectroscopy.

Strength of "Light" Ferritic and Austenitic Steels Based on the Fe - Mn - Al - C System

NASA Astrophysics Data System (ADS)

Kaputkina, L. M.; Svyazhin, A. G.; Smarygina, I. V.; Kindop, V. E.

2017-01-01

The phase composition, the hardness, the mechanical properties at room temperature, and the resistance to hot (950 - 1000°C) and warm (550°C) deformation are studied for cast deformable "light" ferritic and austenitic steels of the Fe - (12 - 25)% Mn - (0 - 15)% Al - (0 - 2)% C system alloyed additionally with about 5% Ni. The high-aluminum high-manganese low-carbon and carbonless ferritic steels at a temperature of about 0.5 T melt have a specific strength close to that of the austenitic steels and may be used as weldable scale-resistant and wear-resistant materials. The high-carbon Fe - (20 - 24)% Mn - (5 - 9)% Al - 5% Ni - 1.5% C austenitic steels may be applied as light high-strength materials operating at cryogenic temperatures after a solution treatment and as scale- and heat-resistant materials in an aged condition.

Post-weld Tempered Microstructure and Mechanical Properties of Hybrid Laser-Arc Welded Cast Martensitic Stainless Steel CA6NM

NASA Astrophysics Data System (ADS)

Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

2016-12-01

Manufacturing of hydroelectric turbine components involves the assembly of thick-walled stainless steels using conventional multi-pass arc welding processes. By contrast, hybrid laser-arc welding may be an attractive process for assembly of such materials to realize deeper penetration depths, higher production rates, narrower fusion, and heat-affected zones, and lower distortion. In the present work, single-pass hybrid laser-arc welding of 10-mm thick CA6NM, a low carbon martensitic stainless steel, was carried out in the butt joint configuration using a continuous wave fiber laser at its maximum power of 5.2 kW over welding speeds ranging from 0.75 to 1.2 m/minute. The microstructures across the weldment were characterized after post-weld tempering at 873 K (600 °C) for 1 hour. From microscopic examinations, the fusion zone was observed to mainly consist of tempered lath martensite and some residual delta-ferrite. The mechanical properties were evaluated in the post-weld tempered condition and correlated to the microstructures and defects. The ultimate tensile strength and Charpy impact energy values of the fully penetrated welds in the tempered condition were acceptable according to ASTM, ASME, and industrial specifications, which bodes well for the introduction of hybrid laser-arc welding technology for the manufacturing of next generation hydroelectric turbine components.

Molecular characterization of natural biofilms from household taps with different materials: PVC, stainless steel, and cast iron in drinking water distribution system.

PubMed

Lin, Wenfang; Yu, Zhisheng; Chen, Xi; Liu, Ruyin; Zhang, Hongxun

2013-09-01

Microorganism in drinking water distribution system may colonize in biofilms. Bacterial 16S rRNA gene diversities were analyzed in both water and biofilms grown on taps with three different materials (polyvinyl chloride (PVC), stainless steel, and cast iron) from a local drinking water distribution system. In total, five clone libraries (440 sequences) were obtained. The taxonomic composition of the microbial communities was found to be dominated by members of Proteobacteria (65.9-98.9 %), broadly distributed among the classes Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria. Other bacterial groups included Firmicutes, Acidobacteria, Bacteroidetes, Cyanobacteria, and Deinococcus-Thermus. Moreover, a small proportion of unclassified bacteria (3.5-10.6 %) were also found. This investigation revealed that the bacterial communities in biofilms appeared much more diversified than expected and more care should be taken to the taps with high bacterial diversity. Also, regular monitor of outflow water would be useful as potentially pathogenic bacteria were detected. In addition, microbial richness and diversity in taps ranked in the order as: PVC < stainless steel < cast iron. All the results interpreted that PVC would be a potentially suitable material for use as tap component in drinking water distribution system.

Milder Etchant For Penetrant Inspection

NASA Technical Reports Server (NTRS)

O'Tousa, Joseph E.; Thomas, Clark S.

1990-01-01

New etching solution for chemical penetrant inspection of Inconel(R) 718 castings and weldments. Etchant does not introduce artifacts mistaken for defects. Applied by swabbing or by immersion. Used to detect unwanted residues of Nioro(R) (or equivalent) gold brazing alloy on type 347 stainless steel.

Exodermic bridge deck performance evaluation.

DOT National Transportation Integrated Search

2010-07-01

In 1998, the Wisconsin DOT completed a two"leaf bascule bridge in Green Bay with an exodermic deck system. The exodermic deck consisted of 4.5"in thick cast"in"place reinforced concrete supported by a 5.19"in tall unfilled steel grid. The concrete an...

A Reaction Between High Mn-High Al Steel and CaO-SiO2-Type Molten Mold Flux: Part I. Composition Evolution in Molten Mold Flux

NASA Astrophysics Data System (ADS)

Kim, Min-Su; Lee, Su-Wan; Cho, Jung-Wook; Park, Min-Seok; Lee, Hae-Geon; Kang, Youn-Bae

2013-04-01

In order to elucidate the reaction mechanism between high Mn-high Al steel such as twin-induced plasticity steel and molten mold flux composed mainly of CaO-SiO2 during continuous casting process, a series of laboratory-scale experiments were carried out in the present study. Molten steel and molten flux were brought to react in a refractory crucible in a temperature range between 1713 K to 1823 K (1440 °C to 1550 °C) and composition evolution in the steel and the flux was analyzed using inductively coupled plasma atomic emission spectroscopy, X-ray fluorescence, and electron probe microanalysis. The amount of SiO2 in the flux was significantly reduced by Al in the steel; thus, Al2O3 was accumulated in the flux as a result of a chemical reaction, 4[Al] + 3(SiO2) = 3[Si] + 2(Al2O3). In order to find a major factor which governs the reaction, a number of factors ((pct CaO/pct SiO2), (pct Al2O3), [pct Al], [pct Si], and temperature) were varied in the experiments. It was found that the above chemical reaction was mostly governed by [pct Al] in the molten steel. Temperature had a mild effect on the reaction. On the other hand, (pct CaO/pct SiO2), (pct Al2O3), and [pct Si] did not show any noticeable effect on the reaction. Apart from the above reaction, the following reactions are also thought to happen simultaneously: 2[Mn] + (SiO2) = [Si] + 2(MnO) and 2[Fe] + (SiO2) = [Si] + 2(FeO). These oxide components were subsequently reduced by Al in the molten steel. Na2O in the molten flux was gradually decreased and the decrease was accelerated by increasing [pct Al] and temperature. Possible reactions affecting the Al2O3 accumulation are summarized.

The space shuttle advanced solid rocket motor: Quality control and testing

NASA Technical Reports Server (NTRS)

1991-01-01

The Congressional committees that authorize the activities of NASA requested that the National Research Council (NRC) review the testing and quality assurance programs for the Advanced Solid Rocket Motor (ASRM) program. The proposed ASRM design incorporates numerous features that are significant departures from the Redesigned Solid Rocket Motor (RSRM). The NRC review concentrated mainly on these features. Primary among these are the steel case material, welding rather than pinning of case factory joints, a bolted field joint designed to close upon firing the rocket, continuous mixing and casting of the solid propellant in place of the current batch processes, use of asbestos-free insulation, and a lightweight nozzle. The committee's assessment of these and other features of the ASRM are presented in terms of their potential impact on flight safety.

Thermal Aging Phenomena in Cast Duplex Stainless Steels

DOE PAGES

Byun, T. S.; Yang, Y.; Overman, N. R.; ...

2015-11-12

We used cast stainless steels (CASSs)for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr-rich alpha-phase by Spinodal decomposition of delta-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This article intends to providemore » an introductory overview on the thermal aging phenomena in LWR-relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. Moreover, an approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, an equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program, and the results are used to describe the precipitation behaviors in duplex stainless steels. Our results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.« less

Effects of Zr, Ti, and Al Additions on Nonmetallic Inclusions and Impact Toughness of Cast Low-Alloy Steel

NASA Astrophysics Data System (ADS)

Bizyukov, Pavel V.; Giese, Scott R.

2017-04-01

A microalloying of the low-carbon and low-alloy cast steel was conducted with Zr, Ti, and Al that were added to the steel in four combinations. After heat treatment, the samples were tested for impact toughness at room temperature using the Charpy method. The highest values of impact toughness were obtained in the group treated with Zr, while Zr-Ti and Zr-Ti-Al groups showed moderate toughness values; the lowest values were observed in the Zr-Al group. Difference among the treatment groups was observed in the fracture mechanisms, morphology, and area distribution of the inclusions. High toughness values achieved in the trials treated with zirconium corresponded with smooth ductile fracture. The metal treated with a combination of zirconium and titanium had a relatively small area occupied by inclusions, but its toughness was also moderate. Lowest impact toughness values corresponded with the larger area occupied by the inclusions in the trials treated with aluminum. Also, a connection between the solubility product [Al][N] and impact toughness was established. The study also provides a qualitative description and quantitative analysis of the nonmetallic inclusions formation as a result of microalloying treatment. The precipitation sequence of the inclusions was described based on the thermochemical calculations for the nonmetallic compounds discovered in the experimental steel. A description of the size distribution, morphology, and composition was conducted for the oxides, nitrides, sulfides, and multiphase particles.

Thermal Aging Phenomena in Cast Duplex Stainless Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Byun, T. S.; Yang, Y.; Overman, N. R.

Cast stainless steels (CASSs) have been extensively used for the large components of light water reactor (LWR) power plants such as primary coolant piping and pump casing. The thermal embrittlement of CASS components is one of the most serious concerns related to the extended-term operation of nuclear power plants. Many past researches have concluded that the formation of Cr–rich α'-phase by Spinodal decomposition of δ-ferrite phase is the primary mechanism for the thermal embrittlement. Cracking mechanism in the thermally-embrittled duplex stainless steels consists of the formation of cleavage at ferrite and its propagation via separation of ferrite-austenite interphase. This articlemore » intends to provide an introductory overview on the thermal aging phenomena in LWR relevant conditions. Firstly, the thermal aging effect on toughness is discussed in terms of the cause of embrittlement and influential parameters. An approximate analysis of thermal reaction using Arrhenius equation was carried out to scope the aging temperatures for the accelerated aging experiments to simulate the 60 and 80 years of services. Further, equilibrium precipitation calculation was performed for model CASS alloys using the CALPHAD program and the results are used to describe the precipitation behaviors in duplex stainless steels. These results are also to be used to guide an on-going research aiming to provide knowledge-based conclusive prediction for the integrity of the CASS components of LWR power plants during the service life extended up to and beyond 60 years.« less

Fast and Accurate Prediction of Stratified Steel Temperature During Holding Period of Ladle

NASA Astrophysics Data System (ADS)

Deodhar, Anirudh; Singh, Umesh; Shukla, Rishabh; Gautham, B. P.; Singh, Amarendra K.

2017-04-01

Thermal stratification of liquid steel in a ladle during the holding period and the teeming operation has a direct bearing on the superheat available at the caster and hence on the caster set points such as casting speed and cooling rates. The changes in the caster set points are typically carried out based on temperature measurements at the end of tundish outlet. Thermal prediction models provide advance knowledge of the influence of process and design parameters on the steel temperature at various stages. Therefore, they can be used in making accurate decisions about the caster set points in real time. However, this requires both fast and accurate thermal prediction models. In this work, we develop a surrogate model for the prediction of thermal stratification using data extracted from a set of computational fluid dynamics (CFD) simulations, pre-determined using design of experiments technique. Regression method is used for training the predictor. The model predicts the stratified temperature profile instantaneously, for a given set of process parameters such as initial steel temperature, refractory heat content, slag thickness, and holding time. More than 96 pct of the predicted values are within an error range of ±5 K (±5 °C), when compared against corresponding CFD results. Considering its accuracy and computational efficiency, the model can be extended for thermal control of casting operations. This work also sets a benchmark for developing similar thermal models for downstream processes such as tundish and caster.

Oxidation of Slurry Aluminide Coatings on Cast Stainless Steel Alloy CF8C-Plus at 800oC in Water Vapor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haynes, James A; Armstrong, Beth L; Dryepondt, Sebastien N

A new, cast austenitic stainless steel, CF8C-Plus, has been developed for a wide range of high temperature applications, including diesel exhaust components, turbine casings and turbocharger housings. CF8C-Plus offers significant improvements in creep rupture life and creep rupture strength over standard CF8C steel. However, at higher temperatures and in more aggressive environments, such as those containing significant water vapor, an oxidation-resistant protective coating will be necessary. The oxidation behavior of alloys CF8C and CF8C-Plus with various aluminide coatings were compared at 800oC in air plus 10 vol% water vapor. Due to their affordability, slurry aluminides were the primary coating systemmore » of interest, although chemical vapor deposition (CVD) and pack cementation coatings were also compared. Additionally, a preliminary study of the low cycle fatigue behavior of aluminized CF8C-Plus was conducted at 800oC. Each type of coating provided substantial improvements in oxidation behavior, with simple slurry aluminides showing very good oxidation resistance after 4,000 h testing in water vapor. Preliminary low cycle fatigue results indicated that thicker aluminide coatings degraded high temperature fatigue properties of CF8C-Plus, whereas thinner coatings did not. Results suggest that appropriately designed slurry aluminide coatings are a viable option for economical, long-term oxidation protection of austenitic stainless steels in water vapor.« less

In vitro corrosion behavior of cast iron-platinum magnetic alloys.

PubMed

Watanabe, I; Hai, K; Tanaka, Y; Hisatsune, K; Atsuta, M

2001-05-01

The objective of this study was to investigate the corrosion resistance of cast Fe-Pt alloys of varying compositions for use as attachment keepers and to make a comparison with the corrosion resistance of magnetic stainless steel. The corrosion behavior of cast Fe-Pt alloy keepers (Fe-40 at%Pt, Fe-38 at%Pt, Fe-37 at%Pt and Fe-36 at%Pt) was evaluated by means of an immersion test and an anodic polarization test. The solutions used were a 1.0% lactic acid aqueous solution (pH=2.3) (10 ml) and 0.9% NaCl solution (pH=7.3) (10 ml). As a control, the corrosion resistance of a magnetic stainless steel keeper (SUS 447J1: HICOREX) was also measured. Chromium and platinum ions were not detected in either the 1.0% lactic acid or 0.9% NaCl solutions. The only released ions detected were the Fe ions in the 1.0% lactic acid solution. The amounts of Fe ions released from the Fe-40 at%Pt and Fe-38 at%Pt alloys were significantly (p<0.05) lower than from the Fe-37at%Pt, Fe-36 at%Pt and SUS 447J1 alloys. In the anodic polarization test, the potentials at the beginning of passivation for the four Fe-Pt alloys were higher than for the SUS 447J1 alloy in both solutions. The Fe-Pt alloys, especially the alloys with higher Pt percentages (Fe-40 and 38 at%Pt), indicated a high corrosion resistance compared to the magnetic stainless steel keeper. A reduction in the Pt percentage may decrease the corrosion resistance in the oral environment.

Laser surface texturing of cast iron steel: dramatic edge burr reduction and high speed process optimisation for industrial production using DPSS picosecond lasers

NASA Astrophysics Data System (ADS)

Bruneel, David; Kearsley, Andrew; Karnakis, Dimitris

2015-07-01

In this work we present picosecond DPSS laser surface texturing optimisation of automotive grade cast iron steel. This application attracts great interest, particularly in the automotive industry, to reduce friction between moving piston parts in car engines, in order to decrease fuel consumption. This is accomplished by partially covering with swallow microgrooves the inner surface of a piston liner and is currently a production process adopting much longer pulse (microsecond) DPSS lasers. Lubricated interface conditions of moving parts require from the laser process to produce a very strictly controlled surface topography around the laser formed grooves, whose edge burr height must be lower than 100 nm. To achieve such a strict tolerance, laser machining of cast iron steel was investigated using an infrared DPSS picosecond laser (10ps duration) with an output power of 16W and a repetition rate of 200 kHz. The ultrashort laser is believed to provide a much better thermal management of the etching process. All studies presented here were performed on flat samples in ambient air but the process is transferrable to cylindrical geometry engine liners. We will show that reducing significantly the edge burr below an acceptable limit for lubricated engine production is possible using such lasers and remarkably the process window lies at very high irradiated fluences much higher that the single pulse ablation threshold. This detailed experimental work highlights the close relationship between the optimised laser irradiation conditions as well as the process strategy with the final size of the undesirable edge burrs. The optimised process conditions are compatible with an industrial production process and show the potential for removing extra post)processing steps (honing, etc) of cylinder liners on the manufacturing line saving time and cost.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hagen Schempf; Daphne D'Zurko

Under funding from the Department of Energy (DOE) and the Northeast Gas Association (NGA), Carnegie Mellon University (CMU) developed an untethered, wireless remote controlled inspection robot dubbed Explorer. The project entailed the design and prototyping of a wireless self-powered video-inspection robot capable of accessing live 6- and 8-inch diameter cast-iron and steel mains, while traversing turns and Ts and elbows under real-time control with live video feedback to an operator. The design is that of a segmented actively articulated and wheel-leg powered robot design, with fisheye imaging capability and self-powered battery storage and wireless real-time communication link. The prototype wasmore » functionally tested in an above ground pipe-network, in order to debug all mechanical, electrical and software subsystems, and develop the necessary deployment and retrieval, as well as obstacle-handling scripts. A pressurized natural gas test-section was used to certify it for operation in natural gas at up to 60 psig. Two subsequent live-main field-trials in both cast-iron and steel pipe, demonstrated its ability to be safely launched, operated and retrieved under real-world conditions. The system's ability to safely and repeatably exidrecover from angled and vertical launchers, traverse multi-thousand foot long pipe-sections, make T and varied-angle elbow-turns while wirelessly sending live video and handling command and control messages, was clearly demonstrated. Video-inspection was clearly shown to be a viable tool to understand the state of this critical buried infrastructure, irrespective of low- (cast-iron) or high-pressure (steel) conditions. This report covers the different aspects of specifications, requirements, design, prototyping, integration and testing and field-trialing of the Explorer platform.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanaka, T.; Kameyama, M.; Urabe, Y.

At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel thanmore » for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.« less

Development of High Heat Input Welding High Strength Steel Plate for Oil Storage Tank in Xinyu Steel Company

NASA Astrophysics Data System (ADS)

Zhao, Hemin; Dong, Fujun; Liu, Xiaolin; Xiong, Xiong

This essay introduces the developed high-heat input welding quenched and tempered pressure vessel steel 12MnNiVR for oil storage tank by Xinyu Steel, which passed the review by the Boiler and Pressure Vessel Standards Technical Committee in 2009. The review comments that compared to the domestic and foreign similar steel standard, the key technical index of enterprise standard were in advanced level. After the heat input of 100kJ/cm electro-gas welding, welded points were still with excellent low temperature toughness at -20°C. The steel plate may be constructed for oil storage tank, which has been permitted by thickness range from 10 to 40mm, and design temperature among -20°C-100°C. It studied microstructure genetic effects mechanical properties of the steel. Many production practices indicated that the mechanical properties of products and the steel by stress relief heat treatment of steel were excellent, with pretreatment of hot metal, converter refining, external refining, protective casting, TMCP and heat treatment process measurements. The stability of performance and matured technology of Xinyu Steel support the products could completely service the demand of steel constructed for 10-15 million cubic meters large oil storage tank.

A Reaction Between High Mn-High Al Steel and CaO-SiO2-Type Molten Mold Flux: Part II. Reaction Mechanism, Interface Morphology, and Al2O3 Accumulation in Molten Mold Flux

NASA Astrophysics Data System (ADS)

Kang, Youn-Bae; Kim, Min-Su; Lee, Su-Wan; Cho, Jung-Wook; Park, Min-Seok; Lee, Hae-Geon

2013-04-01

Following a series of laboratory-scale experiments, the mechanism of a chemical reaction 4[{Al}] + 3({SiO}_2) = 3[{Si}] + 2({Al}_2{O}_3) between high-alloyed TWIP (TWin-Induced Plasticity) steel containing Mn and Al and molten mold flux composed mainly of CaO-SiO2 during the continuous casting process is discussed in the present article in the context of kinetic analysis, morphological evolution at the reaction interface. By the kinetic analysis using a two-film theory, a rate-controlling step of the chemical reaction at the interface between the molten steel and the molten flux is found to be mass transport of Al in a boundary layer of the molten steel, as long as the molten steel and the molten flux phases are concerned. Mass transfer coefficient of the Al in the boundary layer (k_{{Al}}) is estimated to be 0.9 to 1.2 × 10-4 m/s at 1773 K (1500 ^{circ}C). By utilizing experimental data at various temperatures, the following equation is obtained for the k_{{Al}}; ln k_{{Al}} = -14,290/T - 1.1107. Activation energy for the mass transfer of Al in the boundary layer is 119 kJ/mol, which is close to a value of activation energy for mass transfer in metal phase. The composition evolution of Al in the molten steel was well explained by the mechanism of Al mass transfer. On the other hand, when the concentration of Al in the steel was high, a significant deviation of the composition evolution of Al in the molten steel was observed. By observing reaction interface between the molten steel and the molten flux, it is thought that the chemical reaction controlled by the mass transfer of Al seemed to be disturbed by formation of a solid product layer of MgAl2O4. A model based on a dynamic mass balance and the reaction mechanism of mass transfer of Al in the boundary layer for the low Al steel was developed to predict (pct Al2O3) accumulation rate in the molten mold flux.

40 CFR 464.30 - Applicability; description of the ferrous casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ferrous casting subcategory. 464.30 Section 464.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Ferrous Casting Subcategory § 464.30 Applicability; description of the ferrous casting subcategory. The...

Clean Cast Steel Technology: Effect of Micro-porosity on Tensile and Charpy Properties of Four Cast Steels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffin, John, A.; Bates, Charles, E.

2005-09-19

The effect of these large shrink cavities on mechanical properties could be easily calculated using well established engineering formulas. Over the years, increases in computational and metallurgical resources have allowed the modeler to improve accuracy and increase the complexity of numerical predictors. An accurate prediction of micro-porosity, not observable using conventional radiographic techniques, and an engineering understanding of the effect on mechanical properties would give a designer confidence in using a more efficient casting design and a lower safety factor. This will give castings an additional design advantage. The goal of this project is to provide current and future modelers/designersmore » with a tensile and Charpy property dataset for validation of micro-porosity predictors. The response of ultimate strength, elongation, and reduction in area to micro-porosity was very similar in all four alloys. Ultimate strength was largely unaffected by tensile fracture surface porosity until values of about 25% were reached and decreased linearly with increasing values. Elongation and reduction in area decreased sharply after less than 5% fracture surface porosity. Niyama values of about 0.7 were produced sound material and acceptable tensile properties. Ultrasonic velocities of 0.233 in/usec and higher produced acceptable tensile properties. Metallographic examination revealed a ratio of 4-6 to 1 in fracture surface porosity to metallographic porosity. Charpy impact properties were largely unaffected by the microporosity concentrations examined in this study and did not correlate to either Niyama values, fracture surface porosity, or metallographic porosity.« less

An investigation of preload relaxation behaviour of three zinc- aluminum alloys

NASA Astrophysics Data System (ADS)

Mir, A. A.

2016-08-01

Zinc alloy castings are usually assembled together or mounted by screwed steel fasteners, and are tightened to a predetermined torque to develop the required tensile preload in the fastener. Due to relaxation processes in the castings, creep may cause a partial preload loss at an elevated temperature. The equipment used for load relaxation tests consists of a loadmonitoring device, an oil bath, and a data-acquisition system. A load cell monitoring device is used to monitor the load loss in an ISO-metric M6*1 steel screw set into sand castings made from alloys No. 3, No. 5 and No. 2 and tightened to produce an initial preload of 6 kN. The castings were held at constant temperature in the range 80 - 120°C in an oil bath. The oil bath maintains the desired test temperature throughout the experiment. All tests were conducted for periods of up to 160 h. For all alloys, the initial load loss was high, decreasing gradually with time, but not ceasing. The load loss increased rapidly with test temperature, and almost all of the relaxation curves approximated to a logarithmic decay of load with time. Alloy No. 2 had the best resistance to load loss, with No. 5 next and No. 3 worst at all temperatures. The lower resistance to relaxation of alloy No. 3 was mainly due to the lower relaxation strength of copper-free primary dendrites, whereas in alloys No. 5 and No. 2, the higher copper contents contribute greatly to their relaxation strength in the form of second-phase particles.

LOCATING LEAKS WITH ACOUSTIC TECHNOLOGY

EPA Science Inventory

Many water distribution systems in this country are almost 100 years old. About 26 percent of piping in these systems is made of unlined cast iron or steel and is in poor condition. Many methods that locate leaks in these pipes are time-consuming, costly, disruptive to operations...

Austempered ductile iron (ADI) for railroad wheels : final report.

DOT National Transportation Integrated Search

2017-01-31

The purpose of this project is to investigate the potential for austempered ductile iron (ADI) to be used as an alternative material for the production of rail wheels, which are currently cast or forged steel which is commonly heat treated. ADI has s...

In situ TEM study of G-phase precipitates under heavy ion irradiation in CF8 cast austenitic stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Wei-Ying; Li, Meimei; Zhang, Xuan

2015-09-01

Thermally-aged cast austenitic stainless steels (CASS) CF8 was irradiated with 1 MeV Kr ions at 300, 350 and 400°C to 1.88x10^15 ions/cm2 (~3 dpa) at the IVEM-Tandem Facility at the Argonne National Laboratory. Before irradiation, the distribution of G-phase precipitates in the ferrite showed strong spatial variations, and both their size and density were affected by the ferrite-austenite phase boundary and presence of M23C6 carbides. Under 300°C irradiation, in-situ TEM observation showed G-phase precipitates were relatively unchanged in the vicinity of the phase boundary M23C6 carbides, while the density of G-phase precipitates increased with increasing dose within the ferrite matrix.more » Coarsening of G-phase precipitates was observed in the vicinity of phase boundary M23C6 carbides at 350°C and 400°C.« less

Materials and processes for aircraft environmental controls in the 1990's

NASA Astrophysics Data System (ADS)

Delgrosso, E. J.; Zajac, T.; Tseka, J.

1980-10-01

Changes in materials and processes expected to be used in aircraft environmental control systems (ECS) in the 1990s are analyzed, and a forecast is presented. Results of the study show that the most advanced development would be in the use of a cast high strength alloy steel, i.e., a steel with below 8% alloy content, and a 225 KSI annealed tensile strength. To assure complete densification and enhancement of properties, the casting would be HIP, and modification of its surface chemistry could be achieved through ion implantation. As candidate methods for imparting surface protection, laser glazing and chemical vapor deposition are mentioned. The anticipated changes in the materials and techniques used for construction of ECS components are: the development of rapid solidification rate powders for the production of some alloy systems such as Al-Mg-Li, bearing alloy CRB-7, and titanium alloys, 'near-net-shape' processing, and the use of advanced fiber-reinforced plastics.

In situ TEM study of G-phase precipitates under heavy ion irradiation in CF8 cast austenitic stainless steel

NASA Astrophysics Data System (ADS)

Chen, Wei-Ying; Li, Meimei; Zhang, Xuan; Kirk, Marquis A.; Baldo, Peter M.; Lian, Tiangan

2015-09-01

Thermally-aged cast austenitic stainless steels (CASS) CF8 was irradiated with 1 MeV Kr ions at 300, 350 and 400 °C to 1.88 × 1019 ions/m2 (∼3 dpa) at the IVEM-Tandem Facility at the Argonne National Laboratory. Before irradiation, the distribution of G-phase precipitates in the ferrite showed spatial variations, and both their size and density were affected by the ferrite-austenite phase boundary and presence of M23C6 carbides. Under 300 °C irradiation, in situ TEM observation showed G-phase precipitates were relatively unchanged in the vicinity of the phase boundary M23C6 carbides, while the density of G-phase precipitates increased with increasing dose within the ferrite matrix. Coarsening of G-phase precipitates was observed in the vicinity of phase boundary M23C6 carbides at 350 °C and 400 °C.

Development of high purity large forgings for nuclear power plants

NASA Astrophysics Data System (ADS)

Tanaka, Yasuhiko; Sato, Ikuo

2011-10-01

The recent increase in the size of energy plants has been supported by the development of manufacturing technology for high purity large forgings for the key components of the plant. To assure the reliability and performance of the large forgings, refining technology to make high purity steels, casting technology for gigantic ingots, forging technology to homogenize the material and consolidate porosity are essential, together with the required heat treatment and machining technologies. To meet these needs, the double degassing method to reduce impurities, multi-pouring methods to cast the gigantic ingots, vacuum carbon deoxidization, the warm forging process and related technologies have been developed and further improved. Furthermore, melting facilities including vacuum induction melting and electro slag re-melting furnaces have been installed. By using these technologies and equipment, large forgings have been manufactured and shipped to customers. These technologies have also been applied to the manufacture of austenitic steel vessel components of the fast breeder reactors and components for fusion experiments.

The influence of the internal microbiome on the materials used for construction of the transmission natural gas pipelines in the Lodz Province

NASA Astrophysics Data System (ADS)

Staniszewska, Agnieszka; Jastrzębska, Magdalena; Ziemiński, Krzysztof

2017-10-01

This paper presents investigation results of the influence of gas microbes on the biocorrosion rate of the materials used for gas pipelines construction in the Lodz Province. Samples of two types of carbon steel and cast iron were stored in the laboratory pipeline model reflecting the real conditions of working natural gas pipelines were. In the next step the influence of cathodic protection with parameters recommended for protection of underground structures was tested. Analyses of biological corrosion products generated on the test surface were carried out using a scanning electron microscope with an X-ray analyzer. The level of ATP was measured to confirm presence of the adsorbed microorganisms on the observed structures. Corrosion rates were determined by gravimetric methods. In the course of the study it was revealed that the rate of biocorrosion of steel is lower than that for cast iron. Our results also proved that the weight corrosion rate depends on the number of adhered microorganisms. In addition, it has been found that application of the carbon steel cathodic protection decreases its weight corrosion rate. The information obtained will help to increase the knowledge on the rate of biological corrosion causing losses/pits inside gas pipline.

Strengthening of σ phase in a Fe20Cr9Ni cast austenite stainless steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Y.Q., E-mail: yqwang@ahut.edu.cn; School of Materials Science and Engineering, Anhui University of Technology, Maanshan, Anhui, 243002; Han, J.

2013-10-15

The strengthening mechanism of σ phase in a Fe20Cr9Ni cast austenite stainless steel used for primary coolant pipes of nuclear power plants has been investigated. The yield and ultimate tensile strengths of aged specimens increased comparing with those of the unaged ones. It was found that the increase of strengths is due to the hard and brittle (σ + γ{sub 2}) structure which decomposed from α phase in the steel. Fracture surfaces of specimens after in situ tensile test showed that the inhibition of (σ + γ{sub 2}) structure on the dislocation movements was more significant than ferrite although cracksmore » started predominately at σ/γ{sub 2} interfaces. The (σ + γ{sub 2}) structure behaves like a fiber reinforced composite material. - Highlights: • The strengthening mechanism of σ phase in a Fe20Cr9Ni CASS is investigated. • The yield and ultimate tensile strengths increase with increasing of σ phase. • The increase of strengths is due to hard and brittle (σ + γ{sub 2}) structure. • The (σ + γ{sub 2}) structure in CASS behaves like a fibre reinforced composite material. • The σ/γ{sub 2} and α/σ/γ{sub 2} boundaries hinder the movement of dislocation.« less

Interfacial Phenomena in Fe/Stainless Steel-TiC Systems and the Effect of Mo

NASA Astrophysics Data System (ADS)

Kiviö, Miia; Holappa, Lauri; Yoshikawa, Takeshi; Tanaka, Toshihiro

2014-12-01

Titanium carbide is used as reinforcement particles in composites due to its hardness, wear resistance and stability. This work is a part of the study in which titanium carbides are formed in stainless steel castings in the mold to improve the wear resistance of a certain surface of the casting. Such local reinforcement is a very potential method but it is a quite demanding task requiring profound knowledge of interfacial phenomena in the system, wettability, stability, dissolution and precipitation of new phases in production of these materials. Good wetting between different constituents in the material is a key factor to attain maximal positive effects. Mo is used with TiC or Ti(C,N) reinforcement in composites to improve wettability. In this work the effect of Mo on the phenomena in Fe/stainless steel-TiC systems was examined by wetting experiments between the substrate and the alloy. Wetting was not significantly improved by adding Mo to the systems. Core-rim type carbides as well as more homogenous carbide particles were observed. Overall the carbide particles are very complex regarding to their chemistry, size and shape which aspects have to be taken into account in the development of these materials and manufacturing processes.

Gating geometry studies of thin-walled 17-4PH investment castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maguire, M.C.; Zanner, F.J.

1992-11-01

The ability to design gating systems that reliably feed and support investment castings is often the result of ``cut-and-try`` methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channelmore » thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.« less

Gating geometry studies of thin-walled 17-4PH investment castings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maguire, M.C.; Zanner, F.J.

1992-01-01

The ability to design gating systems that reliably feed and support investment castings is often the result of cut-and-try'' methodology. Factors such as hot tearing, porosity, cold shuts, misruns, and shrink are defects often corrected by several empirical gating design iterations. Sandia National Laboratories is developing rules that aid in removing the uncertainty involved in the design of gating systems for investment castings. In this work, gating geometries used for filling of thin walled investment cast 17-4PH stainless steel flat plates were investigated. A full factorial experiment evaluating the influence of metal pour temperature, mold preheat temperature, and mold channelmore » thickness were conducted for orientations that filled a horizontal flat plate from the edge. A single wedge gate geometry was used for the edge-gated configuration. Thermocouples placed along the top of the mold recorded metal front temperatures, and a real-time x-ray imaging system tracked the fluid flow behavior during filling of the casting. Data from these experiments were used to determine the terminal fill volumes and terminal fill times for each gate design.« less

Effect of Cerium Doped on the Poly(3-(Trimethoxysilyl)propyl methacrylate) Characteristic as Corrosion Protection Material of Carbon Steel

NASA Astrophysics Data System (ADS)

Rochmah, D. N.; Syakir, N.; Susilawati, T.; Suryaningsih, S.; Fitrilawati

2017-05-01

The hybrid polymer precursor was synthesized from monomer of 3-(trimethoxysilyl) propyl methacrylate (TMSPMA) using sol-gel method and doped with inhibitor of Cerium Nitrate Hexahydrate with a concentration of 0.2%. The synthesized material was coated on a carbon steel surface by solution casting technique and followed by a photopolymerisation process. Corrosion tests were performed by using Electrochemical Impedance Spectroscopy (EIS) in 3.5% NaCl at the critical temperature of 75°C. Result of EIS data and their fitting analysis using an equivalent circuit model shows that a coating of poly(TMSPMA)-Cerium on the surface of carbon steel form a layer of protection and caused increasing of impedance value significantly. The impedance is higher compared to the carbon steel that coated with poly(TMSPMA) only.

Casting technology for ODS steels - dispersion of nanoparticles in liquid metals

NASA Astrophysics Data System (ADS)

Sarma, M.; Grants, I.; Kaldre, I.; Bojarevics, A.; Gerbeth, G.

2017-07-01

Dispersion of particles to produce metal matrix nanocomposites (MMNC) can be achieved by means of ultrasonic vibration of the melt using ultrasound transducers. However, a direct transfer of this method to produce steel composites is not feasible because of the much higher working temperature. Therefore, an inductive technology for contactless treatment by acoustic cavitation was developed. This report describes the samples produced to assess the feasibility of the proposed method for nano-particle separation in steel. Stainless steel samples with inclusions of TiB2, TiO2, Y2O3, CeO2, Al2O3 and TiN have been created and analyzed. Additional experiments have been performed using light metals with an increased value of the steady magnetic field using a superconducting magnet with a field strength of up to 5 T.

A comparative study of the microstructures observed in statically cast and continuously cast Bi-In-Sn ternary eutectic alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sengupta, S.; Soda, H.; McLean, A.

2000-01-01

A ternary eutectic alloy with a composition of 57.2 pct Bi, 24.8 pct In, and 18 pct Sn was continuously cast into wire of 2 mm diameter with casting speeds of 14 and 79 mm/min using the Ohno Continuous Casting (OCC) process. The microstructures obtained were compared with those of statically cast specimens. Extensive segregation of massive Bi blocks, Bi complex structures, and tin-rich dendrites was found in specimens that were statically cast. Decomposition of {radical}Sn by a eutectoid reaction was confirmed based on microstructural evidence. Ternary eutectic alloy with a cooling rate of approximately 1 C/min formed a doublemore » binary eutectic. The double binary eutectic consisted of regions of BiIn and decomposed {radical}Sn in the form of a dendrite cell structure and regions of Bi and decomposed {radical}Sn in the form of a complex-regular cell. The Bi complex-regular cells, which are a ternary eutectic constituent, existed either along the boundaries of the BiIn-decomposed {radical}Sn dendrite cells or at the front of elongated dendrite cell structures. In the continuously cast wires, primary Sn dendrites coupled with a small Bi phase were uniformly distributed within the Bi-In alloy matrix. Neither massive Bi phase, Bi complex-regular cells, no BiIn eutectic dendrite cells were observed, resulting in a more uniform microstructure in contrast to the heavily segregated structures of the statically cast specimens.« less

Accuracy of ringless casting and accelerated wax-elimination technique: a comparative in vitro study.

PubMed

Prasad, Rahul; Al-Keraif, Abdulaziz Abdullah; Kathuria, Nidhi; Gandhi, P V; Bhide, S V

2014-02-01

The purpose of this study was to determine whether the ringless casting and accelerated wax-elimination techniques can be combined to offer a cost-effective, clinically acceptable, and time-saving alternative for fabricating single unit castings in fixed prosthodontics. Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax-elimination method; the second group was cast using the ringless investment technique and accelerated wax-elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax-elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax-elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two-way ANOVA to determine statistical significance. The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p < 0.05) than those castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax-elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax-elimination method as a vital alternative to the time-consuming conventional technique of casting restorations in fixed prosthodontics. © 2013 by the American College of Prosthodontists.

Final Report, Volume 2, The Development of Qualification Standards for Cast Duplex Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Steven, W.; Lundin, Carl, W.

2005-09-30

The scope of testing cast Duplex Stainless Steel (DSS) required testing to several ASTM specifications, while formulating and conducting industry round robin tests to verify and study the reproducibility of the results. ASTM E562 (Standard Test Method for Determining Volume Fraction by Systematic manual Point Count) and ASTM A923 (Standard Test Methods for Detecting Detrimental Intermetallic Phase in Wrought Duplex Austenitic/Ferritic Stainless Steels) were the specifications utilized in conducting this work. An ASTM E562 industry round robin, ASTM A923 applicability study, ASTM A923 industry round robin, and an ASTM A923 study of the effectiveness of existing foundry solution annealing proceduresmore » for producing cast DSS without intermetallic phases were implemented. In the ASTM E562 study, 5 samples were extracted from various cast austenitic and DSS in order to have varying amounts of ferrite. Each sample was metallographically prepared by UT and sent to each of 8 participants for volume fraction of ferrite measurements. Volume fraction of ferrite was measured using manual point count per ASTM E562. FN was measured from the Feritescope® and converted to volume fraction of ferrite. Results indicate that ASTM E562 is applicable to DSS and the results have excellent lab-to-lab reproducibility. Also, volume fraction of ferrite conversions from the FN measured by the Feritescope® were similar to volume fraction of ferrite measured per ASTM E562. In the ASTM A923 applicability to cast DSS study, 8 different heat treatments were performed on 3 lots of ASTM A890-4A (CD3MN) castings and 1 lot of 2205 wrought DSS. The heat treatments were selected to produce a wide range of cooling rates and hold times in order to study the suitability of ASTM A923 to the response of varying amounts on intermetallic phases [117]. The test parameters were identical to those used to develop ASTM A923 for wrought DSS. Charpy V-notch impact samples were extracted from the castings and wrought DSS and tested per ASTM A923 method B (Charpy impact test). Method A (sodium hydroxide etch test) was performed on one half of a fractured Charpy V-notch impact sample and Method C (ferric chloride corrosion weight loss test) was performed on another half. Test results for the three cast lots and one wrought lot indicate that ASTM A923 is relevant for detecting intermetallic phases in cast DSS. In the ASTM A923 round robin study, five laboratories conducted ASTM A923 Methods A & C on cast DSS material and the lab-to-lab reproducibility of the data was determined. Two groups of samples were sent to the participants. Group 1 samples were tested per ASTM A923 Method A, group 2 samples were tested by ASTM A923 Method C. Testing procedures for this round robin study were identical to those used in the ASTM A923 applicability study. Results from this round robin indicate that there is excellent lab-to-lab reproducibility of ASTM A923 with respect to cast DSS and that ASTM A923 could be expanded to cover both wrought and cast DSS. In the ASTM A923 study of the effectiveness of existing foundry solution annealing procedures for producing cast DSS without intermetallic phases, Ten heats of ASTM A890-4A (CD3MN) in the foundry solution annealed condition were tested per ASTM A923 Methods A, B, & C. Testing of these materials per ASTM A923 was used to determine if the foundry solution anneal procedures were adequate to completely eliminate any intermetallic phases, which may have precipitated during the casting and subsequent heat treatment processes. All heats showed no sign of intermetallic phase per Method A, passed minimum Charpy impact energy requirements per Method B (> 40 ft-lbs @ -40°C (-40°F)), and showed negligible weight loss per Method C (< 10 mdd). These results indicate that the solution annealing procedure used by foundries is adequate to produce a product free from intermetallic phases.« less

Final Report, Volume 2, The Development of Qualification Standards for Cast Duplex Stainless Steel

DOE Office of Scientific and Technical Information (OSTI.GOV)

Russell, Steven, W.; Lundin, Carl, D.

2005-09-30

The scope of testing cast Duplex Stainless Steel (DSS) required testing to several ASTM specifications, while formulating and conducting industry round robin tests to verify and study the reproducibility of the results. ASTM E562 (Standard Test Method for Determining Volume Fraction by Systematic manual Point Count) and ASTM A923 (Standard Test Methods for Detecting Detrimental Intermetallic Phase in Wrought Duplex Austenitic/Ferritic Stainless Steels) were the specifications utilized in conducting this work. An ASTM E562 industry round robin, ASTM A923 applicability study, ASTM A923 industry round robin, and an ASTM A923 study of the effectiveness of existing foundry solution annealing proceduresmore » for producing cast DSS without intermetallic phases were implemented. In the ASTM E562 study, 5 samples were extracted from various cast austenitic and DSS in order to have varying amounts of ferrite. Each sample was metallographically prepared by UT and sent to each of 8 participants for volume fraction of ferrite measurements. Volume fraction of ferrite was measured using manual point count per ASTM E562. FN was measured from the Feritescope{reg_sign} and converted to volume fraction of ferrite. Results indicate that ASTM E562 is applicable to DSS and the results have excellent lab-to-lab reproducibility. Also, volume fraction of ferrite conversions from the FN measured by the Feritescope{reg_sign} were similar to volume fraction of ferrite measured per ASTM E562. In the ASTM A923 applicability to cast DSS study, 8 different heat treatments were performed on 3 lots of ASTM A890-4A (CD3MN) castings and 1 lot of 2205 wrought DSS. The heat treatments were selected to produce a wide range of cooling rates and hold times in order to study the suitability of ASTM A923 to the response of varying amounts on intermetallic phases [117]. The test parameters were identical to those used to develop ASTM A923 for wrought DSS. Charpy V-notch impact samples were extracted from the castings and wrought DSS and tested per ASTM A923 method B (Charpy impact test). Method A (sodium hydroxide etch test) was performed on one half of a fractured Charpy V-notch impact sample and Method C (ferric chloride corrosion weight loss test) was performed on another half. Test results for the three cast lots and one wrought lot indicate that ASTM A923 is relevant for detecting intermetallic phases in cast DSS. In the ASTM A923 round robin study, five laboratories conducted ASTM A923 Methods A & C on cast DSS material and the lab-to-lab reproducibility of the data was determined. Two groups of samples were sent to the participants. Group 1 samples were tested per ASTM A923 Method A, group 2 samples were tested by ASTM A923 Method C. Testing procedures for this round robin study were identical to those used in the ASTM A923 applicability study. Results from this round robin indicate that there is excellent lab-to-lab reproducibility of ASTM A923 with respect to cast DSS and that ASTM A923 could be expanded to cover both wrought and cast DSS. In the ASTM A923 study of the effectiveness of existing foundry solution annealing procedures for producing cast DSS without intermetallic phases, Ten heats of ASTM A890-4A (CD3MN) in the foundry solution annealed condition were tested per ASTM A923 Methods A, B, & C. Testing of these materials per ASTM A923 was used to determine if the foundry solution anneal procedures were adequate to completely eliminate any intermetallic phases, which may have precipitated during the casting and subsequent heat treatment processes. All heats showed no sign of intermetallic phase per Method A, passed minimum Charpy impact energy requirements per Method B (> 40 ft-lbs {at} -40 C (-40 F)), and showed negligible weight loss per Method C (< 10 mdd). These results indicate that the solution annealing procedure used by foundries is adequate to produce a product free from intermetallic phases.« less

Solid State Joining of Magnesium to Steel

NASA Astrophysics Data System (ADS)

Jana, Saumyadeep; Hovanski, Yuri; Pilli, Siva P.; Field, David P.; Yu, Hao; Pan, Tsung-Yu; Santella, M. L.

Friction stir welding and ultrasonic welding techniques were applied to join automotive magnesium alloys to steel sheet. The effect of tooling and process parameters on the post-weld microstructure, texture and mechanical properties was investigated. Static and dynamic loading were utilized to investigate the joint strength of both cast and wrought magnesium alloys including their susceptibility and degradation under corrosive media. The conditions required to produce joint strengths in excess of 75% of the base metal strength were determined, and the effects of surface coatings, tooling and weld parameters on weld properties are presented.

Investigation of Electrodeposited Alloys and Pure Metals as Substitutes for Zinc and Cadmium for Protective Finishes for Steel Parts of Aircraft

DTIC Science & Technology

1949-09-01

ON LOAN FROM 7k a. **+dU fefeÄtüiÄ: .<*-#=« Investigation of Electrodeposited Alloys and Pure Metals as Substitutes for Zinc and Cadmium for...graphs Eight alloys, selected as being superior to pure zinc or cadmium for protecting steel, were evaluated on the basis of static and dynamic... zinc -silver alloy of 25% silver. A tabulated summary of the testing program on all cast and electrodeposited alloys tested is included. * and

Development of Fine-Grained, Low-Carbon Bainitic Steels with High Strength and Toughness Produced Through the Conventional Hot-Rolling and Air-Cooling

NASA Astrophysics Data System (ADS)

Dhua, Sanjay Kumar; Sarkar, Partha Pratim; Saxena, Atul; Jha, Bimal Kumar

2016-12-01

Low-carbon bainitic steels have created enormous interest among scientists across the world in the past few decades because of their high strength, toughness, and weldability replacing the conventional quenched and tempered medium-carbon steels. Three experimental steels with varying alloy additions were made in a 100-kg laboratory induction furnace and cast into 100-mm-diameter cylindrical ingots. These ingots were hot-rolled and air-cooled to 6-mm plates in an experimental rolling mill with selected thermomechanical parameters. Steels processed through this process provided an ultrafine low-carbon bainitic microstructure with maximum yield strength (YS) and ultimate tensile strength (UTS) 575 and 705 MPa, respectively. The Charpy impact toughness of the experimental steels was excellent, and at 253 K (-20 °C), it varied from 114 to 170 Joules. Cu-B-added steel was found to give an optimum combination of strength, YS-575 MPa, and toughness, 114 J at 253 K (-20 °C). Thus, fine-grained, low-carbon bainitic steels could be developed with a proper combination of alloying elements and thermomechanical parameters even by air-cooling.

Investigations on Heat Treatment of a High-Speed Steel Roll

NASA Astrophysics Data System (ADS)

Fu, Hanguang; Qu, Yinhu; Xing, Jiandong; Zhi, Xiaohui; Jiang, Zhiqiang; Li, Mingwei; Zhang, Yi

2008-08-01

High-carbon high-speed steels (HSS) are very abrasion-resistant materials primarily due to their high hardness MC-type carbide and high hardness martensitic matrix. The effects of quenching and tempering treatment on the microstructure, mechanical properties, and abrasion resistance of centrifugal casting high-carbon HSS roll were studied. Different microstructures and mechanical properties were obtained after the quenching and tempering temperatures of HSS roll were changed. With air-cooling and sodium silicate solution cooling, when the austenitizing temperature reaches 1273 K, the metallic matrix all transforms into the martensite. Afterwards, the eutectic carbides dissolve into the metallic matrix and their continuous network distribution changes into the broken network. The second hardening temperature of high-carbon HSS roll is around 793 K. No significant changes in tensile strength and elongation percentage are observed unless the tempering temperature is beyond 753 K. The tensile strength increases obviously and the elongation percentage decreases slightly beyond 753 K. However, the tensile strength decreases and the elongation percentage increases when the tempering temperature exceeds 813 K. When the tempering temperature excels 773 K, the impact toughness has a slight decrease. Tempering at 793-813 K, high-carbon HSS roll presents excellent abrasion resistance.

Effect of Secondary Cooling Conditions on Solidification Structure and Central Macrosegregation in Continuously Cast High-Carbon Rectangular Billet

NASA Astrophysics Data System (ADS)

Zeng, Jie; Chen, Weiqing

2015-10-01

Solidification structures of high carbon rectangular billet with a size of 180 mm × 240 mm in different secondary cooling conditions were simulated using cellular automaton-finite element (CAFE) coupling model. The adequacy of the model was compared with the simulated and the actual macrostructures of 82B steel. Effects of the secondary cooling water intensity on solidification structures including the equiaxed grain ratio and the equiaxed grain compactness were discussed. It was shown that the equiaxed grain ratio and the equiaxed grain compactness changed in the opposite direction at different secondary cooling water intensities. Increasing the secondary cooling water intensity from 0.9 or 1.1 to 1.3 L/kg could improve the equiaxed grain compactness and decrease the equiaxed grain ratio. Besides, the industrial test was conducted to investigate the effect of different secondary cooling water intensities on the center carbon macrosegregation of 82B steel. The optimum secondary cooling water intensity was 0.9 L/kg, while the center carbon segregation degree was 1.10. The relationship between solidification structure and center carbon segregation was discussed based on the simulation results and the industrial test.

Casting made simple using modified sprue design: an in vitro study.

PubMed

Baskaran, B Eswaran; Geetha Prabhu, K R; Prabhu, R; Krishna, G Phani; Eswaran, M A; Gajapathi, B

2014-01-01

Success in dental casting restorations for fixed partial dentures (FPDs) depends on the castability. Castability is described as the ability of an alloy to faithfully reproduce sharp detail and fine margins of a wax pattern. The goal of a prosthodontist is to provide the patient with restorations that fit precisely. Regardless of the alloy used for casting, the casting technique should yield a casted alloy, which should possess sufficient mass, surface hardness and minimal porosity after casting. Twenty patterns for casting were made from three-dimensional printed resin pattern simulating a 3 unit FPD and casted using modified sprue technique. Later test samples were cemented sequentially on stainless steel model using pressure indicating paste and evaluated for vertical marginal gap in eight predetermined reference areas. Marginal gap were measured in microns using Video Measuring System (VMS2010F-CIP Corporation, Korea). A portion of the axial wall of the cast abutments depicting premolar and molar were sectioned and embedded in acrylic resin and tested for micro hardness using Reichert Polyvar 2 Met Microhardness tester (Reichert, Austria) and porosity using Quantimet Image Analyzer (Quantimet Corporation London, England). The results obtained for marginal gap, micro hardness, and porosity of all test samples were tabulated, descriptive statistics were calculated and the values were found to be within the clinically acceptable range. The new sprue technique can be an alternative and convenient method for casting which would minimize metal wasting and less time consuming. However, further studies with same technique on various parameters are to be conducted for its broad acceptance.

The study of chloride ion migration in reinforced concrete under cathodic protection

DOT National Transportation Integrated Search

1999-09-01

The migration of chloride ions in concrete with steel reinforcement was investigated. Mortar blocks (15 cm x 15 cm x 17 cm) of various : composition (water to cement ratio, chloride ion content) were cast with an iron mesh cathode imbedded along one ...

Improving agreement between static method and dynamic formula for driven cast-in-place piles : [technical brief].

DOT National Transportation Integrated Search

2013-08-01

Many transportation facility structures in Wisconsin are founded on driven round, closed-end, steel, pipe piles. The piles are driven to capacity and then filled with concrete. The Wisconsin Department of Transportation (WisDOT) has designed and driv...

8. VIEW OF NEW CONSTRUCTION ON LAUNCH DECK WITH CASTINPLACE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

8. VIEW OF NEW CONSTRUCTION ON LAUNCH DECK WITH CAST-IN-PLACE CONCRETE WALLS AND STEEL STRUCTURE FOR NEW SOUTH-FACING FLAME DEFLECTOR; VIEW TO EAST. - Cape Canaveral Air Station, Launch Complex 17, Facility 28402, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

Age-Strengthening of Cast Iron and Its Effects on Machinability: Review of the Literature

NASA Astrophysics Data System (ADS)

Richards, Von L.

This presentation is a review of the research performed over several years to characterize the age-strengthening behavior of graphitic cast iron alloys (gray iron, ductile iron and CG iron.) Nitrogen in metastable solid solution in ferrite is necessary for the age strengthening to occur, similar to quench aging of steels. The activation energy for age strengthening is similar to that for diffusion of nitrogen. Age-strengthening can occur even if the ferrite is present as a phase in pearlite. However, machinability benefits only occur when there is free ferrite in the microstructure.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nick Cannell; Dr. Mark Samonds; Adi Sholapurwalla

The investment casting process is an expendable mold process where wax patterns of the part and rigging are molded, assembled, shelled and melted to produce a ceramic mold matching the shape of the component to be cast. Investment casting is an important manufacturing method for critical parts because of the ability to maintain dimensional shape and tolerances. However, these tolerances can be easily exceeded if the molding components do not maintain their individual shapes well. In the investment casting process there are several opportunities for the final casting shape to not maintain the intended size and shape, such as shrinkagemore » of the wax in the injection tool, the modification of the shape during shell heating, and with the thermal shrink and distortion in the casting process. Studies have been completed to look at the casting and shell distortions through the process in earlier phases of this project. Dr. Adrian Sabau at Oak Ridge National Labs performed characterizations and validations of 17-4 PH stainless steel in primarily fused silica shell systems with good agreement between analysis results and experimental data. Further tasks provided material property measurements of wax and methodology for employing a viscoelastic definition of wax materials into software. The final set of tasks involved the implementation of the findings into the commercial casting analysis software ProCAST, owned and maintained by ESI Group. This included: o the transfer of the wax material property data from its raw form into separate temperature-dependent thermophysical and mechanical property datasets o adding this wax material property data into an easily viewable and modifiable user interface within the pre-processing application of the ProCAST suite, namely PreCAST o and validating the data and viscoelastic wax model with respect to experimental results« less

Producing thin strips by twin-roll casting—part I: Process aspects and quality issues

NASA Astrophysics Data System (ADS)

Li, Ben Q.

1995-05-01

This two-part paper discusses recent advances in research and development for the direct production of coilable thin strips by twin-roll casting in both the aluminum and steel industries. While the former is empowering the casters to approach the theoretical productivity limit, the latter is striving to put pilot casters into commercial operation. These intensive R&D efforts are derived from the advantages, both economic and metallurgical, offered by the process. As twin-roll casting combines solidification and hot rolling into a single operation, the process requires low capital investment and low operational cost. Also, because of the high solidification rate attained in the process, the thin strips produced have a refined metallurgical structure, characterized by columnar and equiaxed zones with fine intermetallic particles. The enthusiasm about twin-roll casting is now being spread worldwide. This paper focuses on the process aspects and quality control of twin-roll casting. Part II, which will appear in the August issue, will review process modeling and pilot-plant development activities.

Use of cold-bonded, waste oxide briquettes at U.S. Steel Mon Valley BOP shop

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiCaprio, V.; Howell, K.; Harris, R.

1995-09-01

In attempts to avoid the escalated costs and environmental concerns associated with taking waste oxide materials to a landfill, National Recovery Systems Inc., in conjunction with US Steel, built a waste oxide briquetting facility at the USS Mon Valley works (Edgar Thomson plant) to recycle various sludges and scales. The waste oxide briquette is currently a blend of BOP classifier sludge, BOP filter drum sludge, casterscale and hot strip mill scale. In addition to the landfill cost avoidance, the waste oxide briquette is also a low cast, steel scrap supplement. This paper describes the production of the waste oxide briquettemore » and the use of the recycled material at the Edgar Thomson BOP shop.« less

Enhanced Mechanical Properties of 316L Stainless Steel Prepared by Aluminothermic Reaction Subjected to Multiple Warm Rolling

NASA Astrophysics Data System (ADS)

Li, Z. N.; Wei, F. A.; La, P. Q.; Ma, F. L.

2018-05-01

Large dimensional bulk 316L stainless steels were prepared by aluminothermic reaction method and rolled at 973 K (700 °C) with different deformation, the microstructures evolution and mechanical properties were characterized in detail. The results showed that the microstructure of casting steel consists of nanocrystalline/submicrocrystalline/microcrystalline austenite and submicrocrystalline ferrite. After rolling to thickness reduction of 30, 50 and 70%, the submicrocrystalline austenite grains were crushed and dispersed more uniformly in the matrix of the steel, the grain size of submicrocrystalline austenite decreased from 246 to 136 nm. The mechanical properties of the rolled steels were significantly enhanced, with the thickness reduction increased from 30 to 70%, the tensile strength increased from 632 to 824 MPa, the yield strength increased from 425 to 615 MPa, and the elongation increased from 11 to 24%. After rolling to thickness reduction of 70%, the optimized combination of high strength and high ductility was obtained.

78 FR 58518 - Notification of Proposed Production Activity; Benteler Automotive Corporation (Automotive...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-24

.... On its domestic sales, Benteler would be able to choose the duty rate during customs entry procedures...: Metal stampings (crash cans, reinforcement plates, flange plates); bumper beams; toe hooks; cross member shells; side tubes; steel blanks; brackets; gussets; closing plates; castings of aluminum; flat-rolled...

Experimental verification of the influence of time-dependent material properties on long-term bridge characteristics.

DOT National Transportation Integrated Search

2006-08-01

Post-tensioned cast-in-place box girder bridges are commonly used in California. Losses in tension in : the steel prestressing tendons used in these bridges occur over time due to creep and shrinkage of : concrete and relaxation of the tendons. The u...

Improved Blackbody Simulator

DTIC Science & Technology

1974-06-01

28 - ABS Resins ................... 012 0.02 Carbon & Free-Cutting Steels%,. . . . . 27 - Acrylics ......................... 0.12 0.10 Alloy...Borosilicate Glasses................. 0.7 - Zinc At Its Alloys ................. 65.3 60.5 Alkyds .... .... .............. 010 0.20 Tungsten Carbide Cermet...cast).............47.6 25 ABS Resins ............ .. IS 3 FlowbnFie ........... 7 - Cellulose Acetate ............ &. 1.9 Pajadafi CW

New Creep-Resistant Cast Alloys with Improved Oxidation Resistance in Water Vapor at 650–800°C

DOE PAGES

Dryepondt, Sebastien; Pint, Bruce A.; Maziasz, Philip J.

2015-08-13

Cast stainless steel CF8C-Plus (19wt%Cr/12%Ni) has excellent creep properties, but limited oxidation resistance above 700 C in environments containing H 2O. One strategy to improve the alloy oxidation performance is to increase the Cr and Ni concentration. Two new alloys, with, respectively, 21wt%Cr 15wt%Ni and 22wt%Cr 17.5wt%Ni were therefore developed and their long-term oxidation behaviors in humid air were compared with the oxidation behavior of five other cast alloys. Also, at 650 C and 700 C, all the alloys formed internal Cr-rich nodules, and outer nodules or layers rich in Fe and Ni, but they grew a protective Cr-rich innermore » layer over time. At 750 C, the lower alloyed steels such as CF8C-Plus showed large metal losses, but the two new alloys still exhibited a protective oxidation behavior. The 21Cr 15Ni alloy was severely oxidized in locations at 800 C, but that was not the case for the 22Cr 17.5Ni alloy. Thus, the two new modified alloys represent a potential operating temperature gain of, respectively, 50 C and 100 C in aggressive environments compared with the CF8C-Plus alloy.« less

Continuous steel production and apparatus

DOEpatents

Peaslee, Kent D [Rolla, MO; Peter, Jorg J [McMinnville, OR; Robertson, David G. C. [Rolla, MO; Thomas, Brian G [Champaign, IL; Zhang, Lifeng [Trondheim, NO

2009-11-17

A process for continuous refining of steel via multiple distinct reaction vessels for melting, oxidation, reduction, and refining for delivery of steel continuously to, for example, a tundish of a continuous caster system, and associated apparatus.

Prediction of Thermal Fatigue in Tooling for Die-casting Copper via Finite Element Analysis

NASA Astrophysics Data System (ADS)

Sakhuja, Amit; Brevick, Jerald R.

2004-06-01

Recent research by the Copper Development Association (CDA) has demonstrated the feasibility of die-casting electric motor rotors using copper. Electric motors using copper rotors are significantly more energy efficient relative to motors using aluminum rotors. However, one of the challenges in copper rotor die-casting is low tool life. Experiments have shown that the higher molten metal temperature of copper (1085 °C), as compared to aluminum (660 °C) accelerates the onset of thermal fatigue or heat checking in traditional H-13 tool steel. This happens primarily because the mechanical properties of H-13 tool steel decrease significantly above 650 °C. Potential approaches to mitigate the heat checking problem include: 1) identification of potential tool materials having better high temperature mechanical properties than H-13, and 2) reduction of the magnitude of cyclic thermal excursions experienced by the tooling by increasing the bulk die temperature. A preliminary assessment of alternative tool materials has led to the selection of nickel-based alloys Haynes 230 and Inconel 617 as potential candidates. These alloys were selected based on their elevated temperature physical and mechanical properties. Therefore, the overall objective of this research work was to predict the number of copper rotor die-casting cycles to the onset of heat checking (tool life) as a function of bulk die temperature (up to 650 °C) for Haynes 230 and Inconel 617 alloys. To achieve these goals, a 2D thermo-mechanical FEA was performed to evaluate strain ranges on selected die surfaces. The method of Universal Slopes (Strain Life Method) was then employed for thermal fatigue life predictions.

Finite-Element Analysis of Melt Flow in Horizontal Twin-Roll Casting of Magnesium Alloy AZ31

NASA Astrophysics Data System (ADS)

Park, Jong-Jin

Twin-roll casting has been useful in production of thin strips of metals. Especially, the process of horizontal twin-roll casting is often used for magnesium and aluminum alloys, which are lighter in weight and smaller in specific heat as well as latent heat in comparison to steel. In the present investigation, where magnesium alloy AZ31 was targeted, asymmetric behavior of the melt flow due to the gravity was examined in terms of contact length and pressure, and the nozzle for melt ejection was modified for its shape and location. Variations of the melt flow including vortexes were investigated in consideration of heterogeneous nucleation and uniform microstructure. The melt flow was further examined in the perspective of possible randomness of the grain orientation through thickness under differential speeds of rolls.

Structural studies with the use of XRD and Mössbauer spectroscopy of new high Manganese steels

NASA Astrophysics Data System (ADS)

Jablonska, Magdalena Barbara

2014-04-01

New high-strength austenitic and austenitic-ferritic manganese steels represent a significant potential in applications for structural components in the automotive and railway industry due to the excellent combination of high mechanical properties and good plasticity. They belong to the group of steels called AHSS (Advanced High Strength Steels) and UHSS (Ultra High Strength Steels). Application of this combination of properties allows a reduction in the weight of vehicles by the use of reduced cross-section components, and thus to reduce fuel consumption. The development and implementation of industrial production of such interesting and promising steel and its use as construction material requires an improvement of their casting properties and susceptibility to deformation in plastic working conditions. In this work, XRD, Transmission Mössbauer Spectroscopy and Conversion Electron Mössbauer Spectroscopy were employed in a study of the new high-manganese steels with a austenite and austenite-ferrite structure. The influence of the plastic deformation parameters on the changes in the structure, distribution of ferrite and disclosure of the presence of carbides was determined. The analysis of phase transformations in various times using CEMS method made possible to reveal their fine details.

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per Line Basis 10 Table 10 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUE...

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per Line Basis 10 Table 10 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUE...

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per Line Basis 10 Table 10 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUE...

Evolution of Inclusions During 1473 K Heating Process in EH36 Shipbuilding Steel with Mg Addition

NASA Astrophysics Data System (ADS)

Wang, Qiyu; Zou, Xiaodong; Matsuura, Hiroyuki; Wang, Cong

2018-04-01

Inclusion evolution behaviors of EH36 shipbuilding steel with Mg addition were systematically investigated during a 1473 K heating process by means of ex situ SEM examination and in situ CSLM observations. It has been shown that individual MnS inclusions are the dominating phase in the cast billet. However, their number density decreases substantially after heating, while the density of MnS and oxides combined type inclusions is on the rise. In addition, coarsening, split and movement behaviors of MnS inclusions at high temperature are demonstrated here.

Evolution of Inclusions During 1473 K Heating Process in EH36 Shipbuilding Steel with Mg Addition

NASA Astrophysics Data System (ADS)

Wang, Qiyu; Zou, Xiaodong; Matsuura, Hiroyuki; Wang, Cong

2017-12-01

Inclusion evolution behaviors of EH36 shipbuilding steel with Mg addition were systematically investigated during a 1473 K heating process by means of ex situ SEM examination and in situ CSLM observations. It has been shown that individual MnS inclusions are the dominating phase in the cast billet. However, their number density decreases substantially after heating, while the density of MnS and oxides combined type inclusions is on the rise. In addition, coarsening, split and movement behaviors of MnS inclusions at high temperature are demonstrated here.

Field verification for the effectiveness of continuity diaphragms for skewed continuous P/C P/S concrete girder bridges : tech summary.

DOT National Transportation Integrated Search

2009-10-01

The majority of highway bridges are built as cast-in-place reinforced concrete slabs and prestressed concrete : girders. The simple-span precast, prestressed concrete girders made continuous through cast-in-place decks : and diaphragms have been wide...

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per Line Basis 10 Table 10 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS ...

40 CFR Table 10 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 13 2012-07-01 2012-07-01 false Data Requirements for New and Existing Continuous Lamination Lines and Continuous Casting Lines Complying With a Percent Reduction Limit on a Per Line Basis 10 Table 10 to Subpart WWWW of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS ...

This photographic copy of an engineering drawing shows floor plans, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

This photographic copy of an engineering drawing shows floor plans, sections and elevations of Building E-86, with details typical of the steel frame and "Transite" building construction at JPL Edwards Facility. California Institute of Technology, Jet Propulsion Laboratory, Facilities Engineering and Construction Office: "Casting & Curing, Building E-86, Floor Plan, Elevations & Section," drawing no. E86/6, 25 February 1977. California Institute of Technology, Jet Propulsion Laboratory, Plant Engineering: engineering drawings of structures at JPL Edwards Facility. Drawings on file at JPL Plant Engineering, Pasadena, California - Jet Propulsion Laboratory Edwards Facility, Casting & Curing Building, Edwards Air Force Base, Boron, Kern County, CA

75 FR 62110 - Notice of Petitions by Firms for Determination of Eligibility To Apply for Trade Adjustment...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-07

... passive and electro- mechanical component parts. Knickerbocker Machine Shop, Inc. dba 611 Union Boulevard... manufactures Memphis, TX 79245. components of cast steel products. Pequea Machine, Inc 200 Jalyn Drive, P.O..., Warren, PA 16365. manufacturer of solid polyurethane and rubber industrial wear products. Any party...

Hardening of steels and cast irons by passivation of their surface and heat treatment

NASA Astrophysics Data System (ADS)

Kulikov, A. I.

1994-01-01

Examples of the use of a casehardening (CH) method (surface passivation and standard heat treatment) developed to increase hardness and corrosion resistance and to lower the surface roughness of various components and tools — glass molds. piston rings and ball-bearing races — are presented in this paper.

Standard methods for chemical analysis of steel, cast iron, open-hearth iron, and wrought iron

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1973-01-01

Methods are described for determining manganese, phosphorus, sulfur, selenium, copper, nickel, chromium, vanadium, tungsten, titanium, lead, boron, molybdenum ( alpha -benzoin oxime method), zirconium (cupferron --phosphate method), niobium and tantalum (hydrolysis with perchloric and sulfurous acids (gravimetric, titrimetric, and photometric methods)), and beryllium (oxide method). (DHM)

49 CFR Appendix D to Part 192 - Criteria for Cathodic Protection and Determination of Measurements

Code of Federal Regulations, 2012 CFR

2012-10-01

... I. Criteria for cathodic protection— A. Steel, cast iron, and ductile iron structures. (1) A... accordance with sections II and IV of this appendix. This criterion of voltage shift applies to structures... into the structure surface as measured by an earth current technique applied at predetermined current...

49 CFR Appendix D to Part 192 - Criteria for Cathodic Protection and Determination of Measurements

Code of Federal Regulations, 2011 CFR

2011-10-01

... I. Criteria for cathodic protection— A. Steel, cast iron, and ductile iron structures. (1) A... accordance with sections II and IV of this appendix. This criterion of voltage shift applies to structures... into the structure surface as measured by an earth current technique applied at predetermined current...

49 CFR Appendix D to Part 192 - Criteria for Cathodic Protection and Determination of Measurements

Code of Federal Regulations, 2014 CFR

2014-10-01

... I. Criteria for cathodic protection— A. Steel, cast iron, and ductile iron structures. (1) A... accordance with sections II and IV of this appendix. This criterion of voltage shift applies to structures... into the structure surface as measured by an earth current technique applied at predetermined current...

49 CFR Appendix D to Part 192 - Criteria for Cathodic Protection and Determination of Measurements

Code of Federal Regulations, 2013 CFR

2013-10-01

... I. Criteria for cathodic protection— A. Steel, cast iron, and ductile iron structures. (1) A... accordance with sections II and IV of this appendix. This criterion of voltage shift applies to structures... into the structure surface as measured by an earth current technique applied at predetermined current...

Robotic Water Blast Cleaner

NASA Technical Reports Server (NTRS)

Sharpe, M. H.; Roberts, M. L.; Hill, W. E.; Jackson, C. H.

1983-01-01

Water blasting system under development removes hard, dense, extraneous material from surfaces. High pressure pump forces water at supersonic speed through nozzle manipulated by robot. Impact of water blasts away unwanted material from workpiece rotated on air bearing turntable. Designed for removing thermal-protection material, system is adaptable to such industrial processes as cleaning iron or steel castings.

A Numerical Simulation of Transport Phenomena During the Horizontal Single Belt Casting Process Using an Inclined Feeding System

NASA Astrophysics Data System (ADS)

Xu, Mianguang; Isac, Mihaiela; Guthrie, Roderick I. L.

2018-03-01

Horizontal single belt casting (HSBC) has great potential to replace current conventional continuous casting (CCC) processes for sheet metal production, by directly casting 3 to 1 mm sheet for the automobile industry. In the present paper, two-dimensional mathematical models were developed to study transport phenomena, for the case of an inclined wall feeding system for a liquid aluminum wrought alloy (AA6111). Based on the commercial software ANSYS FLUENT 14.5 and user-defined functions, a two-layer turbulence model was used to examine the fluid flow emanating from a slot nozzle set above a water-cooled, high-speed, steel belt. The Volume of Fluid (VOF) method was used to predict the shape of the melt-air interface. A transformed coordinate system (x', y') was established in order to analyze the fluid flow on the inclined wall of the feeding system. The total pressure gauge gradient (∂p total/∂x) was used to describe the behavior of the melt film inside the slot nozzle of the head box. The modeling results show that during the melt film falling process, the total gauge pressure varies within the slot nozzle, which can decrease the stability of the falling film. The first impingement between the falling film and the inclined refractory wall of the feeding system gives rise to a local oscillation, and this influences the stability of the melt film moving downwards. At the rear meniscus position between the inclined wall and the moving belt, there is a clear vibration of the air-melt interface, together with a recirculation zone. The weak vibration of the air-melt interface could be induced by the periodic variation of the melt-air interface. Moreover, the formation of tiny air pockets is predicted. Finally, on the inclined wall of the feeding system, a suitable length of the transition area is needed to avoid over-acceleration of the melt film due to the force of gravity.

A Numerical Simulation of Transport Phenomena During the Horizontal Single Belt Casting Process Using an Inclined Feeding System

NASA Astrophysics Data System (ADS)

Xu, Mianguang; Isac, Mihaiela; Guthrie, Roderick I. L.

2018-06-01

Horizontal single belt casting (HSBC) has great potential to replace current conventional continuous casting (CCC) processes for sheet metal production, by directly casting 3 to 1 mm sheet for the automobile industry. In the present paper, two-dimensional mathematical models were developed to study transport phenomena, for the case of an inclined wall feeding system for a liquid aluminum wrought alloy (AA6111). Based on the commercial software ANSYS FLUENT 14.5 and user-defined functions, a two-layer turbulence model was used to examine the fluid flow emanating from a slot nozzle set above a water-cooled, high-speed, steel belt. The Volume of Fluid (VOF) method was used to predict the shape of the melt-air interface. A transformed coordinate system ( x', y') was established in order to analyze the fluid flow on the inclined wall of the feeding system. The total pressure gauge gradient ( ∂p total/ ∂x) was used to describe the behavior of the melt film inside the slot nozzle of the head box. The modeling results show that during the melt film falling process, the total gauge pressure varies within the slot nozzle, which can decrease the stability of the falling film. The first impingement between the falling film and the inclined refractory wall of the feeding system gives rise to a local oscillation, and this influences the stability of the melt film moving downwards. At the rear meniscus position between the inclined wall and the moving belt, there is a clear vibration of the air-melt interface, together with a recirculation zone. The weak vibration of the air-melt interface could be induced by the periodic variation of the melt-air interface. Moreover, the formation of tiny air pockets is predicted. Finally, on the inclined wall of the feeding system, a suitable length of the transition area is needed to avoid over-acceleration of the melt film due to the force of gravity.

Nitrited-Steel Piston Rings for Engines of High Specific Power

NASA Technical Reports Server (NTRS)

Collins, John H; Bisson, Edmond E; Schmiedlin, Ralph F

1945-01-01

Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26b airplane. Several designs of nitrided-steel piston rings were performance-tested under variable conditions of output. The necessity of good surface finish and conformity of the ring to the bore was indicated in the preliminary tests. Nitrided-steel rings of the same dimensions as cast-iron rings operating on the original piston were unsatisfactory, and the final design was a lighter, rectangular, thin-face-width ring used on a piston having a maximum cross-head area and a revised skirt shape. Results were obtained from single-cylinder and multicylinder engine runs.

METALLOGRAPHIC STUDIES OF SPUTNIK 4 FRAGMENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kammerer, O.F.; Sadofsky, J.; Gurinsky, D.H.

1963-09-01

Metallographic analyses were performed on a fragment of steel recovered after the disintegration of Sputnik 4 and on a melted agglomerate found on the fragment. The examination indicated that the material was a hot-rolled carbon steel similar in hardness to a structural steel with a tensile strength of 3.8 to 4.1 x 10/sup 10/ dynes/cm/sup 2/. The major portion of the fragment exhibited a banded structure characteristic of hot-rolled material. The upper surface was probably heated to the melting point which resulted in the formation of a narrow band similar to an as-cast Widmannstaettn microstructure. The melted material at themore » bottom of the specimen was a porous mass containing several different varieties of inclusions and compounds. (auth)« less

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5940 Cast component. (a) Identification. A cast component is a...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of this...

40 CFR 464.40 - Applicability; description of the zinc casting subcategory.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Applicability; description of the zinc... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS METAL MOLDING AND CASTING POINT SOURCE CATEGORY Zinc Casting Subcategory § 464.40 Applicability; description of the zinc casting subcategory. The provisions of this...

21 CFR 888.5980 - Manual cast application and removal instrument.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual cast application and removal instrument... SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.5980 Manual cast application and removal instrument. (a) Identification. A manual cast application and removal instrument is a...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... the cast heel, toe cap, cast support, and walking iron. (b) Classification. Class I (general controls...

21 CFR 888.5940 - Cast component.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cast component. 888.5940 Section 888.5940 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES... the cast heel, toe cap, cast support, and walking iron. (b) Classification. Class I (general controls...

High-Strength Aluminum Casting Alloy for High-Temperature Applications (MSFC Center Director's Discretionary Fund Final Project No. 97-10)

NASA Technical Reports Server (NTRS)

Lee, J. A.

1998-01-01

A new aluminum-silicon alloy has been successfully developed at Marshall Space Flight Center that has a significant improvement in tensile strength at elevated temperatures (550 to 700 F). For instance, the new alloy shows in average tensile strength of at least 90 percent higher than the current 390 aluminum piston alloy tested at 500 F. Compared to conventional aluminum alloys, automotive engines using the new piston alloy will have improved gas mileage, and may produce less air pollution in order to meet the future U.S. automotive legislative requirements for low hydrocarbon emissions. The projected cost for this alloy is less than $0.95/lb, and it readily allows the automotive components to be cast at a high production volume with a low, fully accounted cost. It is economically produced by pouring molten metal directly into conventional permanent steel molds or die casting.

Friction surfaced Stellite6 coatings

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, K. Prasad; Damodaram, R.; Rafi, H. Khalid, E-mail: khalidrafi@gmail.com

2012-08-15

Solid state Stellite6 coatings were deposited on steel substrate by friction surfacing and compared with Stellite6 cast rod and coatings deposited by gas tungsten arc and plasma transferred arc welding processes. Friction surfaced coatings exhibited finer and uniformly distributed carbides and were characterized by the absence of solidification structure and compositional homogeneity compared to cast rod, gas tungsten arc and plasma transferred coatings. Friction surfaced coating showed relatively higher hardness. X-ray diffraction of samples showed only face centered cubic Co peaks while cold worked coating showed hexagonally close packed Co also. - Highlights: Black-Right-Pointing-Pointer Stellite6 used as coating material formore » friction surfacing. Black-Right-Pointing-Pointer Friction surfaced (FS) coatings compared with casting, GTA and PTA processes. Black-Right-Pointing-Pointer Finer and uniformly distributed carbides in friction surfaced coatings. Black-Right-Pointing-Pointer Absence of melting results compositional homogeneity in FS Stellite6 coatings.« less

Heat Transfer Measurements during DC Casting of Aluminium Part I: Measurement Technique

NASA Astrophysics Data System (ADS)

Bakken, J. A.; Bergström, T.

A method for determination of surface heat transfer to the cooling water and mould based on in-situ temperature measurements in the DC cast ingot has been developed. Three or more steel mantled coaxial thermocouples (0.5 mm diam.) are mounted on a wire frame called a "harp". Allowing the "harp" to freeze into the solid ingots during the casting time-temperature plots T1 (t), T2(t), T3 (t) are obtained for three moving points positioned typically 3, 7 and 11 mm from the ingot surface. From these measurements surface temperature, heat flux and heat transfer coefficients are computed as functions of vertical distance. The computer program is based on steady-state two-dimensional heat balances with convective terms for two fixed volume elements: one around thermocouple T1 and one surface element. A special numerical smoothing procedure is incorporated. The heat of solidification is taken into account.

Development in corrosion resistance by microstructural refinement in Zr-16 SS 304 alloy using suction casting technique

DOE Office of Scientific and Technical Information (OSTI.GOV)

Das, N., E-mail: nirupamd@barc.gov.in; Sengupta, P.; Abraham, G.

Highlights: • Grain refinement was made in Zr–16 wt.% SS alloy while prepared by suction casting process. • Distribution of Laves phase, e.g., Zr{sub 2}(Fe, Cr) was raised in suction cast (SC) Zr–16 wt.% SS. • Corrosion resistance was improved in SC alloy compared to that of arc-melt-cast alloy. • Grain refinement in SC alloy assisted for an increase in its corrosion resistance. - Abstract: Zirconium (Zr)-stainless steel (SS) hybrid alloys are being considered as baseline alloys for developing metallic-waste-form (MWF) with the motivation of disposing of Zr and SS base nuclear metallic wastes. Zr–16 wt.% SS, a MWF alloymore » optimized from previous studies, exhibit significant grain refinement and changes in phase assemblages (soft phase: Zr{sub 2}(Fe, Cr)/α-Zr vs. hard phase: Zr{sub 3}(Fe, Ni)) when prepared by suction casting (SC) technique in comparison to arc-cast-melt (AMC) route. Variation in Cr-distribution among different phases are found to be low in suction cast alloy, which along with grain refinement restricted Cr-depletion at the Zr{sub 2}(Fe, Cr)/Zr interfaces, prone to localized attack. Hence, SC alloy, compared to AMC alloy, showed lower current density, higher potential at the breakdown of passivity and higher corrosion potential during polarization experiments (carried out under possible geological repository environments, viz., pH 8, 5 and 1) indicating its superior corrosion resistance.« less

Clubfoot repair - series (image)

MedlinePlus

... and maintained with a new cast. This serial casting is continued for 3 or more months and is successful in at least 50% of cases. If the casts do not provide enough correction of the clubfoot, surgery is considered.

The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron

NASA Astrophysics Data System (ADS)

Carroll, Jason William

Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in predicting the wear results. The empirical model of Clayton and Su and extended by Afferente and Ciavarella, also provided reasonable semi-quantitative contact fatigue life models for these steels.

Experimental processing and the effects of cenosphere on some mechanical properties of Al6061-SiC composites

NASA Astrophysics Data System (ADS)

Ashoka, E.; Sharanaprabhu, C. M.; Krishnaraja, G. Kodancha; Kudari, S. K.

2018-04-01

In this paper, stir casting technique was utilized to fabricate the hybrid Aluminium alloy (Al 6061) metal matrix reinforced with silicon carbide (SiC) and cenosphere particulates. An Al6061-SiC-Cenosphere hybrid composite is selected with 3wt% of silicon carbide and 3wt%, 6wt% and 9wt% proportions of cenosphere particulates. The uniform distribution of these two reinforcement particulates in Al6061matrix was achieved by stirring and pouring the hybrid composite mixture into the steel mould to accomplish the rectangular shaped casting. These various hybrid composites were studied with respect to its microstructure and some mechanical properties. The rectangular shaped casting of various hybrid composites was machined according to ASTM tensile specimens standards to estimate some mechanical properties. For various cast hybrid composites a comparative study is done with respect to modulus of elasticity, yield stress, percentage elongation and microhardness. Finally, the distribution of particulates and the nature of the tensile specimen fractured surface of various hybrid composites were understood using scanning electron microscope.

46 CFR 153.239 - Use of cast iron.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Use of cast iron. 153.239 Section 153.239 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SHIPS CARRYING BULK... Systems § 153.239 Use of cast iron. (a) Cast iron used in a cargo containment system must meet the...

Recent Aspects on the Effect of Inclusion Characteristics on the Intragranular Ferrite Formation in Low Alloy Steels: A Review

NASA Astrophysics Data System (ADS)

Mu, Wangzhong; Jönsson, Pär Göran; Nakajima, Keiji

2017-04-01

Intragranular ferrite (IGF), which nucleates from specific inclusion surfaces in low alloy steels, is the desired microstructure to improve mechanical properties of steel such as the toughness. This microstructure is especially important in the coarse grain heat affected zone (CGHAZ) of weldments. The latest review paper focusing on the role of non-metallic inclusions in the IGF formation in steels has been reported by Sarma et al. in 2009 (ISIJ int., 49(2009), 1063-1074). In recent years, large amount of papers have been presented to investigate different issues of this topic. This paper mainly highlights the frontiers of experimental and theoretical investigations on the effects of inclusion characteristics, such as the composition, size distribution and number density, on the IGF formation in low carbon low-alloyed steels, undertaken by the group of Applied Process Metallurgy, KTH Royal Institute of Technology. Related results reported in previous studies are also introduced. Also, plausible future work regarding various items of IGF formation is mentioned in each section. This work aims to give a better control of improving the steel quality during casting and in the heat affected zone (HAZ) of weldment, according to the concept of oxide metallurgy.

40 CFR Table 11 to Subpart Wwww of... - Data Requirements for New and Existing Continuous Lamination and Continuous Casting Lines...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Continuous Lamination and Continuous Casting Lines Complying With a Percent Reduction Limit or a Lbs/Ton...: Reinforced Plastic Composites Production Pt. 63, Subpt. WWWW, Table 11 Table 11 to Subpart WWWW of Part 63... With a Percent Reduction Limit or a Lbs/Ton Limit on an Averaging Basis As required in § 63.5865, in...

Damascus steel ledeburite class

NASA Astrophysics Data System (ADS)

Sukhanov, D. A.; Arkhangelsky, L. B.; Plotnikova, N. V.

2017-02-01

Discovered that some of blades Damascus steel has an unusual nature of origin of the excess cementite, which different from the redundant phases of secondary cementite, cementite of ledeburite and primary cementite in iron-carbon alloys. It is revealed that the morphological features of separate particles of cementite in Damascus steels lies in the abnormal size of excess carbides having the shape of irregular prisms. Considered three hypotheses for the formation of excess cementite in the form of faceted prismatic of excess carbides. The first hypothesis is based on thermal fission of cementite of a few isolated grains. The second hypothesis is based on the process of fragmentation cementite during deformation to the separate the pieces. The third hypothesis is based on the transformation of metastable cementite in the stable of angular eutectic carbide. It is shown that the angular carbides are formed within the original metastable colony ledeburite, so they are called “eutectic carbide”. It is established that high-purity white cast iron is converted into of Damascus steel during isothermal soaking at the annealing. It was revealed that some of blades Damascus steel ledeburite class do not contain in its microstructure of crushed ledeburite. It is shown that the pattern of carbide heterogeneity of Damascus steel consists entirely of angular eutectic carbides. Believe that Damascus steel refers to non-heat-resistant steel of ledeburite class, which have similar structural characteristics with semi-heat-resistant die steel or heat-resistant high speed steel, differing from them only in the nature of excess carbide phase.

76 FR 7810 - Certain Hot-Rolled Carbon Steel Flat Products From India: Notice of Court Decision Not in Harmony...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-11

... Policy (``CIP''). See Final Results, and accompanying I&D Memorandum at ``SGOC's Industrial Policy...'' or ``fourth administrative review''), which found that Essar did not benefit from the CIP, cast ``grave doubt'' upon the Department's findings that Essar benefited from the CIP during the fifth POR. See...

75 FR 8114 - In the Matter of Certain Cast Steel Railway Wheels, Processes for Manufacturing or Relating to...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

... any of the trade secrets asserted in this investigation. FOR FURTHER INFORMATION CONTACT: Panyin A... containing same by reason of misappropriation of trade secrets, the threat or effect of which is to... found that Amsted owns the asserted trade secrets, the ABC Trade Secrets, and that respondents...

Analysis of four dental alloys following torch/centrifugal and induction/ vacuum-pressure casting procedures.

PubMed

Thompson, Geoffrey A; Luo, Qing; Hefti, Arthur

2013-12-01

Previous studies have shown casting methodology to influence the as-cast properties of dental casting alloys. It is important to consider clinically important mechanical properties so that the influence of casting can be clarified. The purpose of this study was to evaluate how torch/centrifugal and inductively cast and vacuum-pressure casting machines may affect the castability, microhardness, chemical composition, and microstructure of 2 high noble, 1 noble, and 1 base metal dental casting alloys. Two commonly used methods for casting were selected for comparison: torch/centrifugal casting and inductively heated/ vacuum-pressure casting. One hundred and twenty castability patterns were fabricated and divided into 8 groups. Four groups were torch/centrifugally cast in Olympia (O), Jelenko O (JO), Genesis II (G), and Liberty (L) alloys. Similarly, 4 groups were cast in O, JO, G, and L by an inductively induction/vacuum-pressure casting machine. Each specimen was evaluated for casting completeness to determine a castability value, while porosity was determined by standard x-ray techniques. Each group was metallographically prepared for further evaluation that included chemical composition, Vickers microhardness, and grain analysis of microstructure. Two-way ANOVA was used to determine significant differences among the main effects. Statistically significant effects were examined further with the Tukey HSD procedure for multiple comparisons. Data obtained from the castability experiments were non-normal and the variances were unequal. They were analyzed statistically with the Kruskal-Wallis rank sum test. Significant results were further investigated statistically with the Steel-Dwass method for multiple comparisons (α=.05). The alloy type had a significant effect on surface microhardness (P<.001). In contrast, the technique used for casting did not affect the microhardness of the test specimen (P=.465). Similarly, the interaction between the alloy and casting technique was not significant (P=.119). A high level of castability (98.5% on average) was achieved overall. The frequency of casting failures as a function of alloy type and casting method was determined. Failure was defined as a castability index score of <100%. Three of 28 possible comparisons between alloy and casting combinations were statistically significant. The results suggested that casting technique affects the castability index of alloys. Radiographic analysis detected large porosities in regions near the edge of the castability pattern and infrequently adjacent to noncast segments. All castings acquired traces of elements found in the casting crucibles. The grain size for each dental casting alloy was generally finer for specimens produced by the induction/vacuum-pressure method. The difference was substantial for JO and L. This study demonstrated a relation between casting techniques and some physical properties of metal ceramic casting alloys. Copyright © 2013 Editorial Council for the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Hot cracking during welding and casting

NASA Astrophysics Data System (ADS)

Cao, Guoping

Aluminum welds are susceptible to liquation cracking in the partially melted zone (PMZ). Using the multicomponent Scheil model, curves of temperature vs. fraction solid (T-fS) during solidification were calculated for the PMZ and weld metals (WMs). These curves were used to predict the crack susceptibility by checking if the harmful condition of WM fS > PMZ fS exists during PMZ solidification and reduce the susceptibility by minimizing this condition. This approach was tested against full-penetration welds of alloys 7075 and 2024 and it can be used to guide the selection or development of filler metals. Liquation cracking in the PMZ in welds of Al-Si cast alloys was also investigated. The crack susceptibility was evaluated by circular-patch test, and full-penetration welds made with filler metals 1100, 4043, 4047 and 5356. Liquation cracking was significant with filler metals 1100 and 5356 but slight with filler metals 4043 and 4047. In all welds, liquation cracks were completely backfilled, instead of open as in full-penetration welds of wrought alloys 2219 and 6061. The T-fS curves showed that alloy A357 has a much higher fraction liquid for backfilling before PMZ solidification was essentially over. Hot tearing in Mg-xAl-yCa alloys was studied by constrained rod casting (CRC) in a steel mold. The hot tearing susceptibility decreased significantly with increasing Ca content (y) but did not change much with the Al content (x). An instrumented CRC with a steel mold was developed to detect the onset of hot tearing. The secondary phases, eutectic content, solidification path, and freezing range were examined. Hot tearing in Mg-Al-Sr alloys was also studied by CRC in a steel mold. With Mg-(4,6,8)Al-1.5Sr alloys, the hot tearing susceptibility decreased significantly with increasing Al content. With Mg-(4,6,8)Al-3Sr alloys, the trend was similar but not as significant. At the same Al content, the hot tearing susceptibility decreased significantly with increasing Sr content. Instrumented CRC with a steel mold was also used to test hot tearing of Mg-Al-Sr alloys. Cracking occurred at a higher temperature in alloys most susceptible to cracking than in alloys least susceptible.

The effect of microstructure and strength on the fracture toughness of an 18 Ni, 300 grade maraging steel

NASA Technical Reports Server (NTRS)

Psioda, J. A.; Low, J. R., Jr.

1975-01-01

A 300 grade maraging steel was chosen as a vehicle by which to understand the inverse relationship between strength and toughness in high strength alloys such as the 18 Ni maraging steels. The 18 Ni, 300 grade maraging material was a commercial grade consumable-electrode, vacuum arc remelted heat obtained in the form of forged and annealed plate. The matrix contained a population of second-phase impurity inclusions which was a product of the casting and hot working processes. These inclusions did not change with subsequent precipitation hardening. Changes in microstructure resulting in strength increases were brought about by variations in aging temperature and time. Maximum strength was attained in the 300 grade maraging steel by aging at 427 C (800 F) for 100 hours. Tensile, fatigue precracked Charpy impact, and plane-strain fracture toughness tests were performed at room temperature, 20 C (68 F). With increasing strength the fracture toughness decreases as smaller and smaller inclusions act as sites for void initiation.

The effects of cold work on the microstructure and mechanical properties of intermetallic strengthened alumina-forming austenitic stainless steels

DOE PAGES

Hu, Bin; Baker, Ian; Miller, Michael K.; ...

2015-06-12

In order to achieve energy conversion efficiencies of >50 pct for steam turbines/boilers in power generation systems, materials are required that are both strong and corrosion-resistant at >973 K (700 °C), and economically viable. Austenitic steels strengthened with Laves phase, NiAl and Ni 3Al precipitates, and alloyed with aluminum to improve oxidation resistance, are potential candidate materials for these applications. The microstructure and microchemistry of recently developed alumina-forming austenitic stainless steels have been characterized by scanning electron microscopy, transmission electron microscopy, and synchrotron X-ray diffraction. Different thermo-mechanical treatments were performed on these steels to improve their mechanical performance. These reducedmore » the grain size significantly to the nanoscale (~100 nm) and the room temperature yield strength to above 1000 MPa. Lastly, a solutionizing anneal at 1473 K (1200 °C) was found to be effective for uniformly redistributing the Laves phase precipitates that form upon casting.« less

Correlation between molten vanadium salts and the structural degradation of HK-type steel superheater tubes

NASA Astrophysics Data System (ADS)

de Carvalho Nunes, Frederico; de Almeida, Luiz Henrique; Ribeiro, André Freitas

2006-12-01

HK steels are among the most used heat-resistant cast stainless steels, being corrosion-resistant and showing good mechanical properties at high service temperatures. These steels are widely used in reformer furnaces and as superheater tubes. During service, combustion gases leaving the burners come in contact with these tubes, resulting in corrosive attack and a large weight loss occurs due to the presence of vanadium, which forms low melting point salts, removing the protective oxide layer. In this work the external surface of a tube with dramatic wall thickness reduction was analyzed using light microscopy, scanning electron microscopy, and transmission electron microscopy. The identification of the phases was achieved by energy dispersive spectroscopy (EDS) analyses. The results showed oxides arising from the external surface. In this oxidized region vanadium compounds inside chromium carbide particles were also observed, due to inward vanadium diffusion during corrosion attack. A chemical reaction was proposed to explain the presence of vanadium in the metal microstructure.

Study on the strength characteristics of High strength concrete with Micro steel fibers

NASA Astrophysics Data System (ADS)

Gowdham, K.; Sumathi, A.; Saravana Raja Mohan, K.

2017-07-01

The study of High Strength Concrete (HSC) has become interesting as concrete structures grow taller and larger. The usage of HSC in structures has been increased worldwide and has begun to make an impact in India. Ordinary cementitious materials are weak under tensile loads and fiber reinforced cementitious composites (FRCCs) have been developed to improve this weak point. High Strength concrete containing Alccofine as mineral admixture and reinforced with micro steel fibers were cast and tested to study the mechanical properties. The concrete were designed to have compressive strength of 60 MPa. Mixtures containing 0% and 10% replacement of cement by Alccofine and with 1%, 2% and 3% of micro steel fibers by weight of concrete were prepared. Mixtures incorporating Alccofine with fibers developed marginal increase in strength properties at all curing days when compared to control concrete.

Heat dissipating nuclear reactor with metal liner

DOEpatents

Gluekler, E.L.; Hunsbedt, A.; Lazarus, J.D.

1985-11-21

A nuclear reactor containment including a reactor vessel disposed within a cavity with capability for complete inherent decay heat removal in the earth and surrounded by a cast steel containment member which surrounds the vessel is described in this disclosure. The member has a thick basemat in contact with metal pilings. The basemat rests on a bed of porous particulate material, into which water is fed to produce steam which is vented to the atmosphere. There is a gap between the reactor vessel and the steel containment member. The containment member holds any sodium or core debris escaping from the reactor vessel if the core melts and breaches the vessel.

An Accelerated Method for Testing Soldering Tendency of Core Pins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Han, Qingyou; Xu, Hanbing; Ried, Paul

2010-01-01

An accelerated method for testing die soldering has been developed. High intensity ultrasonic vibrations has been used to simulate the die casting conditions such as high pressure and high impingement speed of molten metal on the pin. Soldering tendency of steels and coated pins has been examined. The results indicate that in the low carbon steel/Al system, the onset of soldering is 60 times faster with ultrasonic vibration than that without ultrasonic vibration. In the H13/A380 system, the onset of soldering reaction is accelerated to 30-60 times. Coating significantly reduces the soldering tendency of the core pins.

Heat dissipating nuclear reactor with metal liner

DOEpatents

Gluekler, Emil L.; Hunsbedt, Anstein; Lazarus, Jonathan D.

1987-01-01

Disclosed is a nuclear reactor containment including a reactor vessel disposed within a cavity with capability for complete inherent decay heat removal in the earth and surrounded by a cast steel containment member which surrounds the vessel. The member has a thick basemat in contact with metal pilings. The basemat rests on a bed of porous particulate material, into which water is fed to produce steam which is vented to the atmosphere. There is a gap between the reactor vessel and the steel containment member. The containment member holds any sodium or core debris escaping from the reactor vessel if the core melts and breaches the vessel.