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1

Wear properties of niobium carbide coatings performed by pack method on AISI 1040 steel  

Microsoft Academic Search

A series of experiments was performed to evaluate tribological properties of niobium carbide coated AISI 1040 steel. In coating process, thermo-reactive diffusion treatment by pack method was performed at the temperatures of 800, 900 and 1000 C for 14 h, respectively. Depending on coating process time and temperature, the thickness of niobium carbide layer formed on substrate ranged from 3.40.5

Ugur Sen

2005-01-01

2

Surface properties of low alloy steel treated by plasma nitrocarburizing prior to laser quenching process  

NASA Astrophysics Data System (ADS)

Laser quenching (LQ) technique is used as a part of duplex treatments to improve the thickness and hardness of the surface layers of steels. The present study is to investigate the surface properties of low alloy steel treated by plasma nitrocarburizing (PNC) prior to a laser quenching process (PNC+LQ). The microstructure and properties of PNC+LQ layer determined are compared with those obtained by PNC and LQ processes. OM, XRD, SEM and EDS analyses are utilized for microstructure observation, phases identification, morphology observation and chemical composition detection, respectively. Microhardness tester and pin-on-disc tribometer are used to investigate the mechanical properties of the modified layers. Laser quenching of plasma nitrocarburized (PNC+LQ) steel results in much improved thickness and hardness of the modified layer in comparison with the PNC or LQ treated specimens. The mechanism is that the introduction of trace of nitrogen decreases the eutectoid point, that is, the transformation hardened region is enlarged under the same temperature distribution. Moreover, the layer treated by PNC+LQ process exhibits enhanced wear resistance, due to the lubrication effect and optimized impact toughness, which is contributed to the formation of oxide film consisting of low nitrogen compound (FeN0.076) and iron oxidation (mainly of Fe3O4).

Wang, Y. X.; Yan, M. F.; Li, B.; Guo, L. X.; Zhang, C. S.; Zhang, Y. X.; Bai, B.; Chen, L.; Long, Z.; Li, R. W.

2015-04-01

3

Optimizing the mechanical properties of M50NiL steel by plasma nitrocarburizing  

NASA Astrophysics Data System (ADS)

In this study, plasma nitrocarburizing at various temperatures in the range of 460-540 C were carried out on M50NiL steel in order to improve wear properties. The nitrocarburizing temperature was optimized to obtain the best wear properties. The phase composition, microstucture and microhardness profiles of nitrocarburized layers of M50NiL steel were characterized by XRD, optical microscope and Vickers microhardness measurements, respectively. Pin-on-disc tribometer and SEM equipped with EDS were applied to measure friction and wear properties and analyze wear mechanisms involved. XRD results show that the amount of ?-Fe2-3(N,C) phase increased as the nitrocarburizing temperature rose form 460 C to 500 C and then decreased at 540 C, while the amount of ??-Fe4(N,C) phase increased as the treatment temperature rose. The hardness of the nitrocarburized layers showed an obvious improvement accompanied with the increasing nitrocarburizing temperature, and obtained the maximum surface hardness of 1287 HV at 540 C. The results of wear tests carried out at various sliding speeds indicated that the wear mechanism depends on sliding speed rather than the nitrocarburizing temperature. With the increase of the sliding speed, the wear mechanism transfers from oxidation mode to abrasive mode. The gradually deceased wear rate of the specimen nitrocarburized at 500 C with the increase of the sliding speed indicated the excellent wear resistance under high sliding speed condition. Therefore, 500 C can be selected as an optimized nitrocarburizing temperature for M50NiL steel.

Zhang, C. S.; Yan, M. F.; Sun, Z.; Wang, Y. X.; You, Y.; Bai, B.; Chen, L.; Long, Z.; Li, R. W.

2014-10-01

4

Anisotropic mechanical properties of the MA956 ODS steel characterized by the small punch testing technique  

NASA Astrophysics Data System (ADS)

The small punch testing technique was used to assess both creep and fracture properties of the MA956 oxide dispersion strengthened ferritic steel. The anisotropy in mechanical properties was addressed, as well as the alloy's susceptibility to thermal embrittlement. Strong anisotropy was found in the material's creep resistance at 725 C for longer rupture times. Anisotropic behavior was also observed for the ductile-brittle transition temperature (DBTT). The origin of the anisotropy can be related to the strongly directional microstructure which enables a large amount of intergranular cracking during straining at both high and low temperatures. The DBTT of the alloy is very high, and can be further increased by at least 200 C after 1000 h of ageing at 475 C, due to the formation of the Cr-rich ?' phase. The particularly high susceptibility of the MA956 to thermal embrittlement is mainly a consequence of its high chromium content.

Turba, K.; Hurst, R. C.; Hhner, P.

2012-09-01

5

The magnetic properties of seamless steel pipe  

Microsoft Academic Search

The magnetic and metallurgical properties of seamless pipe steel have been investigated as a function of position around the pipe circumference. No changes in magnetic properties were found to be associated with the four cycle spiral variations in pipe wall thickness introduced during forging. A weaker single cycle thickness variation was accompanied by a change both in magnetic properties and

S. N. M. Willcock; B. K. Tanner; P. A. Mundell

1987-01-01

6

Characterization and mechanical properties of ultrahigh boron steels produced by powder metallurgy  

SciTech Connect

The present work is part of an investigation into the use of rapid solidification and powder metallurgy techniques to obtain iron-boron alloys with good mechanical properties. Two Fe-B binary alloys and two ultrahigh boron tool steels were gas atomized and consolidated by hot isostatic pressing (HIP) at temperatures ranging from 700 C to 1,100 C to have a fine microstructure. Optimum properties were achieved for the binary alloys at low consolidation temperatures, since the solidification microstructure from the original powders is eliminated and, at the same time, fine microstructures and low porosity are obtained in the alloys. At high temperatures and low strain rates, three of the four alloys exhibited low stress exponents, but only the Fe-2.2 pct B alloy showed tensile elongations higher than 100 pct. At low temperatures, only the Fe-2.2 pct B alloy deformed plastically. This alloy showed values of tensile elongation and ultimate tensile strength that were strongly dependent on testing and consolidation temperatures.

Jimenez, J.A.; Gonzalez-Doncel, G.; Ruano, O.A. [Centro Nacional de Investigaciones Metalurgicas, Madrid (Spain)

1996-07-01

7

Relationship between binder contents and mechanical properties of 17-4 ph stainless steel fabricated by PIM process and sintering  

Microsoft Academic Search

Mechanical properties and microstructures of 17-4 ph stainless steel parts produced using different binder contents (powder\\u000a loading) of powder injection molding (PIM) feedstock have been studied. The tensile and wear properties have been evaluated.\\u000a Wear tests were conducted by a pin-on-disk tribometer, without lubricant, at different loads and sliding distance. SEM examination\\u000a of the fracture sufaces revealed good particle bonding

K. A. Khalil; Sug Won Kim

2006-01-01

8

Assessment of mechanical properties of the martensitic steel EUROFER97 by means of punch tests  

NASA Astrophysics Data System (ADS)

The ball punch test technique was used to evaluate the conventional tensile and impact properties of the tempered martensitic steel EUROFER97 from room temperature down to liquid nitrogen temperature. The testing was carried out on unirradiated material only with small disks, 3 mm in diameter and 0.25 mm in thickness. For comparison, tensile tests were also performed over the same temperature range. Correlations between the load at the plastic bending initiation and the maximum load of the punch tests with the yield stress and the ultimate tensile stress of the tension tests could be established. The temperature dependence of the specific fracture energy of the punch test was used to define a ductile-brittle transition temperature (DBTT) and to correlate this with the DBTT measured from impact Charpy on KLST specimens. The results are compared with other available correlations done in the past on other ferritic steels.

Ruan, Y.; Sptig, P.; Victoria, M.

2002-12-01

9

Mechanical Properties of Sintered Martensitic Stainless Steel Fabricated by Metal Injection Molding Process  

NASA Astrophysics Data System (ADS)

The effects of sintering and heat treatment conditions on the mechanical properties of martensitic stainless steel fabricated by metal injection molding (MIM) process were investigated. The specimens were made by injecting the mixture of gas-atomized powders of 5 m and 10 m in mean particle diameter and a polymer binder into a metallic mold. The injection molded compacts were debound in air at various temperatures between 533 K and 593 K for 7.2 ks. They were sintered in vacuum at various temperatures between 1273 K and 1623 K for 7.2 ks. And the specimens were tempered at various temperatures between 373 K and 973 K after vacuum hardening. The density of the as-sintered compact of 5 m powder was higher than that of the as-sintered compact of 10 m powder. In case of the as-sintered compact of 5 m powder, the tensile strength depended on the change in density, and the tensile strength of the compact sintered at 1373 K was 1600 MPa. On the other hand, in the case of the as-sintered compact of 10 m powder, the tensile strength was rather lower than that of the as-sintered compact of 5 m powder because of coarsening of the grain size. The tensile strength and elongation of the heat-treated compact of 5 m powder were 1800 MPa and 12 %, respectively. The tensile strength and elongation of the heat-treated compact of 10 m powder were 1680 MPa and 10 %, respectively. Thus, the mechanical properties of the compacts were approximately equal to those of the wrought material.

Nakayama, Hideki; Kyogoku, Hideki

10

Stainless Steel Microstructure and Mechanical Properties Evaluation  

SciTech Connect

A nitrogen strengthened 21-6-9 stainless steel plate was spinformed into hemispherical test shapes. A battery of laboratory tests was used to characterize the hemispheres. The laboratory tests show that near the pole (axis) of a spinformed hemisphere the yield strength is the lowest because this area endures the least cold-work strengthening, i.e., the least deformation. The characterization indicated that stress-relief annealing spinformed stainless steel hemispheres does not degrade mechanical properties. Stress-relief annealing reduces residual stresses while maintaining relatively high mechanical properties. Full annealing completely eliminates residual stresses, but reduces yield strength by about 30%.

Switzner, Nathan T

2010-06-01

11

Microstructure and mechanical properties of oxide dispersion strengthened ferritic steel prepared by a novel route  

NASA Astrophysics Data System (ADS)

Nanocrystalline oxide dispersion strengthened (ODS) ferritic steel powders with nominal composition of Fe-14Cr-3W-0.2Ti-0.3Y was synthesized using a sol-gel method combining with hydrogen reduction. X-ray diffraction patterns show that pure Fe-14Cr-3W-0.2Ti-0.3Y body-centered-cubic phase was obtained at a reduction temperature of 1200 C for 3 h. Using such powders the ODS steel was produced by spark plasma sintering (SPS) technique. The energy dispersive spectrometry mapping and transmission electron microscopy results indicate that the oxide particles of Y2Ti2O7 with an average size of 55 nm and particle number density of 3.2 1019 m-3 are homogeneously dispersed in the steel matrix. The tensile strength and uniform elongation of the steel that was SPS sintered and mechanically-thermally treated at 1100 C under a uniaxial pressure reach 1070 MPa and 15%, respectively.

Sun, Q. X.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Hao, T.; Liu, C. S.

2012-05-01

12

The mechanical properties of H13 die steel repaired by a biomimetic laser technique  

NASA Astrophysics Data System (ADS)

The H13 steel specimens with cracks were repaired by pulsed laser welding with filler wire and the laser parameters were analyzed to obtain the weld without defects. Strengthening units with different spacing were fabricated to improve the tensile strength and thermal fatigue resistance of the weld by laser technique on the surfaces of specimens, that is, PS-1, PS-2 and PS-3 for tensile specimens and PS for thermal fatigue specimen. The results indicated that the units have a beneficial effect on improving the tensile strength and thermal fatigue resistance of welded components of H13 steel. The improvement can be attributed to the microstructure characteristics within the units and the spacing of adjacent units is a key factor which affects the strength of weld by biomimetic treatment.

Cong, Dalong; Zhou, Hong; Yang, Miaoqiang; Zhang, Zhihui; Zhang, Peng; Meng, Chao; Wang, Chuanwei

2013-12-01

13

Formation of structure and properties of composite bronzes reinforced by steel dendrites  

NASA Astrophysics Data System (ADS)

The investigation of experimental alloys of the BrZhNKA 9-4-1-1 type has shown the possibility of production of bronzes as antifriction alloys, in which, instead of brittle intermetallic compounds, steel dendrite-like inclusions of, e.g., steel N12K7Yu, are used. In these alloys, the phenomenon of the redistribution of alloying elements (Ni, Co, Al) between the matrix and dendrites in the process of heat treatments has been considered. The growth of these dendrites was found to occur in the solid state via the directional diffusion of Fe, Ni, and Co from the copper matrix to dendrites. This leads to the formation of a shell around them, which represents a substitutional solid solution of Cu, Ni, and Co in iron, e.g., with a composition of Fe6Cu3Ni2Co. On the whole, the mechanical, tribological, and engineering properties of such bronzes, e.g., BrZhNKA 9-4-1-1, are higher than those of the well-known antifriction bronzes BrO10 or BrAZhN 10-4-4.

Potekhin, B. A.; Ilyushin, V. V.; Khristolyubov, A. S.; Zhilyakov, A. Yu.

2014-04-01

14

The magnetic properties of seamless steel pipe  

NASA Astrophysics Data System (ADS)

The magnetic and metallurgical properties of seamless pipe steel have been investigated as a function of position around the pipe circumference. No changes in magnetic properties were found to be associated with the four cycle spiral variations in pipe wall thickness introduced during forging. A weaker single cycle thickness variation was accompanied by a change both in magnetic properties and pearlite fraction. The coercive field predicted from an empirical relationship between grain size and ferrite and pearlite fractions was found to be in excellent agreement with that measured experimentally.

Willcock, S. N. M.; Tanner, B. K.; Mundell, P. A.

1987-03-01

15

A comparative study of the mechanical properties and the behavior of carbon and boron in stainless steel cladding tubes fabricated by PM HIP and traditional technologies  

NASA Astrophysics Data System (ADS)

The ring tensile test method was optimized and successfully used to obtain precise data for specimens of the cladding tubes of AISI type 316 austenitic stainless steels and ferritic-martensitic stainless steel. The positive modifications in the tensile properties of the stainless steel cladding tubes fabricated by powder metallurgy and hot isostatic pressing of melt atomized powders (PM HIP) when compared with the cladding tubes produced by traditional technology were found. Presently, PM HIP is also used in the fabrication of oxide dispersion strengthened (ODS) ferritic-martensitic steels. The high degree of homogeneity of the distribution of carbon and boron as well the high dispersivity of the phase-structure elements in the specimens manufactured via PM HIP were determined by direct autoradiography methods. These results correlate well with the increase of the tensile properties of the specimens produced by PM HIP technology.

Shulga, A. V.

2013-03-01

16

Advances in chemical and physical properties of electric arc furnace carbon steel slag by hot stage processing and mineral mixing.  

PubMed

Slags are recognised as a highly efficient, cost effective tool in the metal processing industry, by minimising heat losses, reducing metal oxidation through contact with air, removing metal impurities and protecting refractories and graphite electrodes. When compared to natural aggregates for use in the construction industry, slags have higher specific weight that acts as an economic deterrent. A method of altering the specific weight of EAFC slag by hot stage processing and mineral mixing, during steel production is presented in this article. The method has minimal interference with the production process of steel, even by limited additions of appropriate minerals at high temperatures. Five minerals are examined, namely perlite, ladle furnace slag, bauxite, diatomite and olivine. Measurements of specific weight are accompanied by X-ray diffraction (XRD) and fluorescence (XRF) analysis and scanning electron microscopy spectral images. It is also shown how altering the chemical composition is expected to affect the furnace refractory lining. Additionally, the process has been repeated for the most suitable mix in gas furnace and physical properties (FI, SI, LA, PSV, AAV, volume stability) examined. Alteration of the specific weight can result in tailoring slag properties for specific applications in the construction sector. PMID:25261762

Liapis, Ioannis; Papayianni, Ioanna

2015-02-11

17

Estimation of mechanical properties of irradiated nuclear pressure vessel steel by use of subsized CT specimen and small punch specimen  

Microsoft Academic Search

This paper reports on the 2-1\\/4 Cr-1M steel that has been selected as the material for the reactor pressure vessel (RPV) of a multipurpose experimental high temperature gas cooled reactor designed by JAERI. The 2-1\\/4 Cr-1M steel has successful records for high temperature pressure vessels in the petrochemical industries and the ASME Code Case authorizes the use of the steel

X. Mao; H. Takahashi; T. Kodaira

1991-01-01

18

The mechansims by which solute nitrogen affects phase transformations and mechanical properties of automotive dual-phase sheet steel  

NASA Astrophysics Data System (ADS)

Dual-phase steels have seen increased use in automotive applications in recent years, in order to meet the goals of weight reduction and occupant safety. Variations in nitrogen content that may be encountered in steel sourced from a basic oxygen furnace process compared to an electric arc furnace process require that dual-phase steel producers understand the ways that nitrogen affects processing and properties. In the current work, the distribution of nitrogen was investigated in a dual-phase steel with a base chemistry of 0.1 C, 2.0 Mn, 0.2 Cr, 0.2 Mo (wt pct) across a range of nitrogen contents (30-159 ppm) with Al (0.2 and 0.08 wt pct), and Ti (0.02 wt pct) additions used for precipitation control of nitrogen amounts. The distribution of nitrogen amongst trapping sites, including precipitates, grain boundaries, dislocations, and interstitial sites (away from other types of defects) was determined from a combination of electrolytic dissolution, internal friction, and three-dimensional atom probe tomography experiments. Various mechanisms by which different amounts and locations of nitrogen affect phase transformations and mechanical properties were identified from quantitative metallography, dilatometric measurement of phase transformations, tensile testing, and nanoindentation hardness testing. Results indicate nitrogen that is not precipitated with Ti or Al (free nitrogen) partitions to austenite (and thus martensite) during typical intercritical annealing treatments, and is mostly contained in Cottrell atmospheres in martensite. Due to the austenite stabilizing effect of nitrogen, the presence of free nitrogen during intercritical annealing leads to a higher austenite fraction in certain conditions. Thus, the presence of free nitrogen in a dual-phase microstructure will lead to an increase in tensile and yield strengths from both an increase in martensite fraction, and an increase in martensite hardness due to solid solution strengthening. Despite the presence of free nitrogen, no yield point elongation was detected in tensile stress-strain results, including after 80 C aging treatments. This was likely due to the partitioning of nitrogen, such that the ferritic regions of the microstructure contained less nitrogen than is required to saturate the high dislocation density in ferrite. Measured tensile and yield strength sensitivities to free nitrogen content range between 7 and 13 GPa/wt pct N.

Brown, Tyson W.

19

Iron and Steel- Properties and Applications  

NSDL National Science Digital Library

This document provides a learning module on iron and steel for use in materials education. The lesson examines the basic properties of iron and steel and includes discussions, demonstrations and suggested optional classroom activities. The materials can be covered in one to two class periods.

Stoebe, Thomas G.

2011-09-20

20

Characterization of mechanical-technological steel properties by Non Linear Harmonics Analysis within the production line  

NASA Astrophysics Data System (ADS)

Mechanical-technological quantities are used to characterize steel and its quality. Here in particular tensile strength, yield strength and anisotropy values are considered. To measure these quantities the magnetoinductive Non Linear Harmonics Analysis (NLHA) has been developed. Its working principle is discussed together with the procedure for measuring, evaluation and calibration. Due to its electromagnetic character the method is fast and less than two seconds are needed per measuring point. Results for non destructive determination of tensile and yield strength as well as anisotropy values within the production line of a steel company are given.

Stegemann, D.; Reimche, W.; Heutling, B.; Krys, A.; Feiste, K. L.; Kroos, J.; Stolzenberg, M.; Westkmper, G.; Angerer, R.

1999-12-01

21

Structure, mechanical properties, and fracture of 20GL cast steel  

NASA Astrophysics Data System (ADS)

The structure and mechanical properties of 20GL steel are studied. It is shown that a significant decrease in the ductility and impact toughness of the steel is caused by intercrystalline fracture, which is induced by a weakening of the intercrystallite bonds due to the existence of coarse lamellar pearlite and nonmetallic inclusions, namely, film inclusions and eutectic-type oxysulfides, at the boundaries of primary crystals. Annealing from a temperature in the intercritical range is found to improve the mechanical properties.

Schastlivtsev, V. M.; Tabatchikova, T. I.; Yakovleva, I. L.; Klyueva, S. Yu.

2014-04-01

22

Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging  

SciTech Connect

Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G. [Battelle Memorial Institute, Columbus, OH (United States)

1997-04-01

23

Mechanical Properties, Thermal Stability and Radiation Damage of Ferritic Steels Processed by Thermal Mechanical Treatments  

E-print Network

AISI American Iron and Steel Institute ASTM American Society of Mechanical Engineers ASME American Society for Testing Materials bcc or BCC Body Centered Cubic CG Coarse Grain CNB Chromium-Nickel Balance DBTT Ductile to Brittle... Loss Spectroscopy FIM Field Ion Microscopy fcc or FCC Face Centered Cubic viii FFTF Fast Flux Test Facility FIB Focused Ion Beam F/M Ferritic/Martensitic GB Grain Boundary GFR Gas Fast Reactors GNB Geometry Necessary...

Song, Miao

2014-08-04

24

Magnetic properties of ?' martensite in austenitic stainless steel studied by a minor-loop scaling law  

NASA Astrophysics Data System (ADS)

We study the scaling behavior of magnetic minor hysteresis loops in strain-induced ferromagnetic ?' martensites in an austenitic 316-type stainless steel. A scaling relationship between the hysteresis loss and the remanence, with a power law exponent of approximately 1.35, was found irrespective of the volume fraction of the ?' martensites as well as temperature. The coefficient of the power law largely decreases with volume fraction, whereas it increases with a decrease in temperature and exhibits a kink at around 40 K, close to the Nel temperature of an austenitic ?' phase. The behavior of the coefficient was interpreted from the viewpoint of the morphology and exchange interaction of ?' martensites.

Kobayashi, Satoru; Kikuchi, Nobuhiro; Takahashi, Seiki; Kamada, Yasuhiro; Kikuchi, Hiroaki

2010-08-01

25

Stainless steel lined composite steel pipe prepared by centrifugal-SHS process  

Microsoft Academic Search

The tension properties, thermal expansion coefficient, microstructure and the causes of crack formation of the stainless steel layer in the composite pipe made by centrifugal-SHS process were investigated. It was shown that the tensile strength is 316 MPa and the percentage elongation is 58%. The nonmetal inclusions make the stainless steel brittle. In the brittle stainless steel layer the crack

Wenjun Xi; Sheng Yin; Shiju Guo; Hoyi Lai

2000-01-01

26

Influence of prestrain history on fracture toughness properties of steels  

Microsoft Academic Search

The effects of prestrain history on fracture toughness properties ( J Ic values and J R curves) of 4340 steel and 316 stainless steel were investigated. It was observed that monotonic prestrain decreased fracture toughness of both steels regardless of prestrain level. Although cyclic prestrain elevated fracture toughness of 4340 steel, it degraded that of 316 stainless steel. The effects

P. K. Liaw; J. D. Landes

1986-01-01

27

Properties of cryogenically worked metals. [stainless steels  

NASA Technical Reports Server (NTRS)

A program was conducted to determine whether the mechanical properties of cryogenically worked 17-7PH stainless steel are suitable for service from ambient to cryogenic temperatures. It was determined that the stress corrosion resistance of the cryo-worked material is quite adequate for structural service. The tensile properties and fracture toughness at room temperature were comparable to titanium alloy 6Al-4V. However, at cryogenic temperatures, the properties were not sufficient to recommend consideration for structural service.

Schwartzberg, F. R.; Kiefer, T. F.

1975-01-01

28

Evaluation of the Joint-Interface Properties of SCM440-S45C Steels Joined by Friction Welding  

NASA Astrophysics Data System (ADS)

The purpose of this study is to investigate experimentally the hardness distributions and micro-structural properties of the dissimilar joints using chrome molybdenum steel (SCM440) to carbon steel (S45C) parts. The experiments were carried out using a beforehand designed and constructed experimental friction welding set-up, constructed as a continuous-drive brake type. The pilot dissimilar welding experiments under different friction pressure and friction time were carried out to obtain optimum welding parameters using visual examination and tensile tests. Vicker's hardness distributions and microstructures in the interfaces of the dissimilar joints for PWHT were also obtained and examined. The obtained results were compared with those of the previous study.

Kim, Seon-Jin; Kong, Yu-Sik; Yoon, Han-Ki; Jung, Won-Taek; Choi, Sung-Woong

29

Tensile property of a hot work tool steel prepared by biomimetic coupled laser remelting process with different laser input energies  

NASA Astrophysics Data System (ADS)

Coupled with the biomimetic principle, a hot work tool steel (4Cr5MoSiV1) was manufactured using a laser with different input energies. Results of tensile tests confirmed that the biomimetic coupled laser remelting (BCLR) process had an advance effect on improving the strength and ductility of 4Cr5MoSiV1 steel simultaneously. Microstructure examinations demonstrated that a fine microstructure along with nano scale carbide was acquired in the BCLR units, which produced an accumulative contribution of grain refinement, precipitation strengthening and a mixed microstructure. Based on the well distribution of the BCLR units, the beneficial effect of stress transfer from the matrix to the units on tensile property was also analyzed.

Wang, Chuanwei; Zhou, Hong; Zhang, Zhihui; Zhao, Yu; Zhang, Peng; Cong, Dalong; Meng, Chao; Tan, Fuxing

2012-09-01

30

Thermal models of ASRM case steel properties  

SciTech Connect

High performance alloy steels require many heat treatment steps in order to realize their potential. These heat treatments create residual stresses and deformations which must be taken into account when designing forgings to insure final machined part tolerances can be met. These residuals can be computed with reasonable precision through thermal stress modeling, provided detailed material property data are known. This paper discusses thermophysical properties determined for HP 9-4-30 steel. A particularly interesting feature of this material is specific heat hysteresis, in which rapid quenches from the austenitic region follow a different c-T curve than do slow equilibrium temperature changes. This hysteresis was determined through a novel combination of thermal modeling with experimental data. The specific heat behavior of HP 9-4-30 should be characteristic of similar alloy steels which undergo phase changes, and this hysteresis needs to be included in thermal models of high temperature quenches. 8 refs.

Rea, S.N.; Cheng, N.; Mohn, W.R. (Aerojet, Iuka, MS (United States) Babcock Wilcox Research Center, Alliance, OH (United States))

1993-01-01

31

X-ray attenuation properties of stainless steel (u)  

SciTech Connect

Stainless steel vessels are used to enclose solid materials for studying x-ray radiolysis that involves gas release from the materials. Commercially available stainless steel components are easily adapted to form a static or a dynamic condition to monitor the gas evolved from the solid materials during and after the x-ray irradiation. Experimental data published on the x-ray attenuation properties of stainless steel, however, are very scarce, especially over a wide range of x-ray energies. The objective of this work was to obtain experimental data that will be used to determine how a poly-energetic x-ray beam is attenuated by the stainless steel container wall. The data will also be used in conjunction with MCNP (Monte Carlos Nuclear Particle) modeling to develop an accurate method for determining energy absorbed in known solid samples contained in stainless steel vessels. In this study, experiments to measure the attenuation properties of stainless steel were performed for a range of bremsstrahlung x-ray beams with a maximum energy ranging from 150 keV to 10 MeV. Bremsstrahlung x-ray beams of these energies are commonly used in radiography of engineering and weapon components. The weapon surveillance community has a great interest in understanding how the x-rays in radiography affect short-term and long-term properties of weapon materials.

Wang, Lily L [Los Alamos National Laboratory; Berry, Phillip C [Los Alamos National Laboratory

2009-01-01

32

Measurement of steel corrosion in concrete by impedance spectroscopy  

NASA Astrophysics Data System (ADS)

Steel corrosion is a major problem for aging bridge structures. The steel corrodes as chloride ions migrate to the buried steel. The properties of the corroded steel-concrete interface change due to the corrosion and can be measured by impedance spectroscopy. A new spectrometer was built to measure concrete slabs. A fitting function to the impedance spectra was used to determine relevant parameters correlated with corrosion. Data from the laboratory and the field demonstrate the utility of this technique.

Bartholomew, Paul; Sumsion, Eric; Guthrie, Spencer; Mazzeo, Brian

2010-10-01

33

Tensile elastic properties of 18:8 chromium-nickel steel as affected by plastic deformation  

NASA Technical Reports Server (NTRS)

The relationship between stress and strain, and between stress and permanent set, for 18:8 alloy as affected by prior plastic deformation is discussed. Hysteresis and creep and their effects on the stress-strain and stress-set curves are also considered, as well as the influence of duration of the rest interval after cold work and the influence of plastic deformation on proof stresses, on the modulus of elasticity at zero stress, and on the curvature of the stress-strain line. A constant (c sub 1) is suggested to represent the variation of the modulus of elasticity with stress.

Mcadam, D J; Mebs, R W

1939-01-01

34

Corrosion properties of sputter-deposited steel thin film for electrical resistance sensor material  

Microsoft Academic Search

Steel thin films for an electrical resistance sensor were prepared by sputter deposition. It was revealed that the electrochemical properties of the thin films were influenced by the surface roughness. Using an Al2O3 substrate with high surface roughness, it was possible to obtain a steel thin film with corrosion characteristics similar to bulk steel. The corrosion rate of the thin

Sungwon Jung; SeonYeob Li; Young-Geun Kim

2006-01-01

35

Strengthening of micro-alloyed sheet steel by oxinitrocarburizing  

SciTech Connect

Producers of small domestic appliances mostly use metal parts made by means of forming out of sheet steel. Requirements are generally strength and corrosion resistance. Martensitic chromium steel (AISI 420) and hard rolled chromium nickel steel (AISI 304) are therefore widely used steel qualities. However, high cost price and limited formability (especially of cold rolled AISI 304 steel) are disadvantages of these qualities. When corrosion resistance is demanded practically no alternatives exist. It would be desirable to have a metallurgical process which achieves high strength and high corrosion resistance after forming. The process of nitrocarburizing followed by oxidizing (oxinitrocarburizing [ONC]), could fulfill these wishes. This presentation will focus on possibilities offered by ONC of sheet steel. Non-alloyed low carbon sheet steel is excellently formable compared with corrosion resistant chromium and cold rolled chromium-nickel steels. The remarkable increase in tensile properties after ONC-treatment of non-alloyed and especially micro-alloyed sheet steel (IF-steel with excellent formability properties) will be presented here. Furthermore the temperature stability of the mechanical properties of these ONC-treated steels, as well as the relation between the content of micro-alloying elements and obtained properties, will be discussed.

Blaauw, H.S.; Post, J. [Phillips DAP B.V., Drachten (Netherlands)

1995-12-31

36

Mechanical properties of four RSP stainless steel alloys  

SciTech Connect

Four austenitic stainless steel alloys were processed by consolidating rapidly solidified gas atomized power using hot extrusion. These materials were characterized by measuring grain growth, hardness, tensile properties from 24 to 800{degrees}C, and creep-rupture at 600{degrees}C.

Korth, G.E.

1996-12-01

37

Influence of prestrain history on fracture toughness properties of steels  

Microsoft Academic Search

The effects of prestrain history on fracture toughness properties (J\\u000a Ic values andJ\\u000a R curves) of 4340 steel and 316 stainless steel were investigated. It was observed that monotonic prestrain decreased fracture\\u000a toughness of both steels regardless of prestrain level. Although cyclic prestrain elevated fracture toughness of 4340 steel,\\u000a it degraded that of 316 stainless steel. The effects of cyclic

P. K. Liaw; J. D. Landes

1986-01-01

38

Author's personal copy Magnetic properties of stainless steels at room and cryogenic temperatures  

E-print Network

properties. Averaged over the ten steels tested the maximum permeability decreased by 8%, the coercive force density, and high magnetic saturation flux density. These steels also have high electrical resistivity magnetic flux density (Bs), and the residual magnetic flux density (Br) for ten stainless steels in round

Oxley, Paul

39

Analysis of the Mechanical Properties of N-Added CMn Structural Steel by the Impulse Internal Friction Technique  

NASA Astrophysics Data System (ADS)

The presence of substitutional solutes has a strong influence on the Snoek effect of interstitial atoms in body-centered cubic (bcc) Fe alloys, such as the structural CMn steel grades produced in hot strip mills. In the current study, bcc Fe-Mn-N alloys were analyzed using the impulse technique and the results were correlated to their mechanical properties and the AlN precipitation characteristics. The broadened Snoek peak related to the octahedral interstitial N could be resolved into three distinct Debye peaks related to the arrangement of Mn atoms surrounding the N atoms. The simulation results suggest that precipitation of AlN occurred mainly during coiling and that the precipitation kinetics was enhanced at higher coiling temperatures. Alloys isothermally held at high temperatures had a yield strength and tensile strength linearly proportional to the difference between the nominal N content and the interstitial N content. The observations point to the pronounced precipitation strengthening effect of AlN after high-temperature coiling simulations. The result also reveals that interstitial N increases both the yield strength and the tensile strength in steels coiled at low temperatures.

Jung, Jaehyuk; Kozeschnik, E.; Han, Seong Ho; De Cooman, Bruno C.

2012-12-01

40

Microstructures and High-Temperature Mechanical Properties of a Martensitic Heat-Resistant Stainless Steel 403Nb Processed by Thermo-Mechanical Treatment  

NASA Astrophysics Data System (ADS)

Thermo-mechanical treatments (TMT) at different rolling deformation temperatures were utilized to process a martensitic heat-resistant stainless steel 403Nb containing 12 wt pct Cr and small additions of Nb and V. Microstructures and mechanical properties at room and elevated temperatures were characterized by scanning electron microscopy, transmission electron microscopy, and hardness, tensile, and creep tests. The results showed that high-temperature mechanical behavior after TMT can be greatly improved and microstructures with refined martensitic lath and finely dispersed nanosized MX carbides could be produced. The particle sizes of M23C6 and MX carbides in 403Nb steel after conventional normalizing and tempering (NT) treatments are about 50 to 160 and 10 to 20 nm, respectively, while those after TMT at 1123 K (850 C) and subsequent tempering at 923 K (650 C) for 2 hours reach about 25 to 85 and 5 to 10 nm, respectively. Under the condition of 260 MPa and 873 K (600 C), the tensile creep rupture life of 403Nb steel after TMT at 1123 K (850 C) is 455 hours, more than 3 times that after conventional NT processes. The mechanisms for improving mechanical properties at elevated temperature were analyzed in association with the existence of finely dispersed nanosized MX particles within martensitic lath. It is the nanosized MX particles having the higher stability at elevated temperature that assist both dislocation hardening and sub-grain hardening for longer duration by pinning the movement of dislocations and sub-grain boundary migration.

Chen, Liqing; Zeng, Zhouyu; Zhao, Yang; Zhu, Fuxian; Liu, Xianghua

2013-11-01

41

Stainless steels in bipolar platesSurface resistive properties of corrosion resistant steel grades during current loads  

Microsoft Academic Search

Instances of an increase in the contact resistance of stainless steel surfaces, resulting a decrease in the efficiency of fuel cells, were reported by automotive developers of PEM fuel cells, who had used the AISI 316L grade (EN 1.4404) in bipolar plates. To identify the reason for this, surface resistive properties were measured for a number of stainless steel grades,

A. K. Iversen

2006-01-01

42

Anisotropic Properties of Stainless SteelClad Aluminum Sheet  

NASA Astrophysics Data System (ADS)

The production of a stainless steelclad aluminum sheet by the cold rolling process is a more efficient and economical approach compared with the other types of processes utilized for the production of such sheets. Because both the stainless steel and aluminum sheets show the highly anisotropic behavior, it is necessary to investigate anisotropic properties of clad sheets for the design of process. In this paper, to investigate the anisotropic properties of stainless steelclad aluminum sheet, two kinds of clad sheets were considered: STS439/AA3003 and STS439/AA1050/STS304 clad sheets. The uni-axial tension tests at 0, 45 and 90 degrees for the rolling direction were performed to obtained yield stresses and R values. The strain ratio at balanced biaxial tension state was measured from compression disk test. In order to describe the anisotropic behavior of the clad sheet, nonquadratic anisotropic yield function Yld2000-2d was utilized.

Kim, Daeyong; Hwang, Bum Kyu; Lee, Young Seon; Kim, Ji Hoon; Kim, Min-Joong

2010-06-01

43

Welding and properties of welds of TMCP-steel  

SciTech Connect

Thermomechanical control process (TMCP) of steel includes a multiplicity of processing schedules of combined thermal and mechanical working treatments that have been developed to optimize the resulting microstructure and mechanical properties of various steel grades. Weld metal properties of multipass submerged arc welded (SAW) TMCP steel joints were investigated in order to study the influences of different welding wires and heat inputs. Weld metal characterization consisted of tensile, Charpy-V Notch (CVN) and hardness testing, and microstructural examination. Cross-weld tensile specimens were tested principally to examine whether HAZ softening, which might have occurred, causes failure in this region. The tests verified that by using the right welding wire; it is possible to achieve weld joint which fulfills the strength requirements and gives satisfactory toughness at low temperatures.

Brederholm, A.T.; Kotamies, J.M.N.; Haenninen, H. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Engineering Materials

1995-12-31

44

Interfacial properties of diffusion bonded Ti6Al4V to AISI 304 stainless steel by inserting a Cu interlayer  

Microsoft Academic Search

The joining characteristics of Ti-6Al-4V with AISI 304 stainless steel by inserting a Cu interlayer was investigated in a\\u000a vacuum-free diffusion bonding process. The diffusion bonds were carried out in the temperature range of 820, 850 and 870C\\u000a for 50, 70 and 90minutes, respectively, under 1MPa load in argon atmosphere. The joining performances of diffusion bonded\\u000a Ti-6Al-4V to AISI 304

N. zdemir; B. Bilgin

2009-01-01

45

Complex Mechanical Properties of Steel  

E-print Network

monitored by electronic or mechanical counters. There are several methods employed to determine the crack length[13, 1517]: direct visual measurement, usually for thin sheet specimens where crack dimensions can be visually inspected; ultrasonic sensing... stress. Hole drilling, ring core technique, bending deflection method, sectioning method and compliance methods fall in this category. Diffraction measurements are based on the study of variations in the interplanar spacing of the polycrystalline...

Dimitriu, Radu

46

Properties of silicon Manganese steel with vanadium and zirconium  

Microsoft Academic Search

1.Steel 36G2S with concentrations of carbon and manganese at the lower limit of the range specified does not satisfy the requi rements for the mechanical properties of steel of strength group K for casting pipe (GQST 632-64).2.The addition of small amounts of vanadium and zirconium to medium-carbon silicon-manganese steel increases the strength and ductile characteristics of the steel and ensures

V. N. Zikeev; B. P. Kolesnik; D. A. Litvinenko; V. T. Ababkov; L. I. Guzevataya

1969-01-01

47

Effect of steel fibers on the mechanical properties of natural lightweight aggregate concrete  

Microsoft Academic Search

In this study, the effect of steel fibers on the mechanical properties of pumice aggregate concrete was investigated. In order to determine the effect of steel fiber ratio on the mechanical properties of concrete, (1) 25%, 50%, 75%, and 100% pumice ratios were used instead of natural aggregate by volume, (2) 0.5%, 1.0%, and 1.5% steel fiber ratios were used

O?uz Ak?n Dzgn; Rstem Gl; Abdulkadir Cneyt Aydin

2005-01-01

48

Hadfield steel coatings on low carbon steel by laser cladding  

Microsoft Academic Search

Austenitic manganese steels with 12% Mn and 1.2% C, known as Hadfield steels, are of great interest owing to their good mechanical properties, especially their high strengthening ratio during plastic deformation. For many applications only a limited thickness of the surface layer is submitted to wear and therefore manufacturing of coatings with the appropriate Fe?Mn?C composition appears an attractive solution.

J. M. Pelletier; F. Oucherif; P. Sallamand; A. B. Vannes

1995-01-01

49

Microstructural Characterization and Properties Evaluation of Ni-Based Hardfaced Coating on AISI 304 Stainless Steel by High Velocity Oxyfuel Coating Technique  

NASA Astrophysics Data System (ADS)

The present study concerns a detailed investigation of microstructural evolution of nickel based hardfaced coating on AISI 304 stainless steel by high velocity oxy-fuel (HVOF) deposition technique. The work has also been extended to study the effect of coating on microhardness, wear resistance and corrosion resistance of the surface. Deposition has been conducted on sand blasted AISI 304 stainless steel by HVOF spraying technique using nickel (Ni)-based alloy [Ni: 68.4 wt pct, chromium (Cr): 17 wt pct, boron (B): 3.9 wt pct, silicon (Si): 4.9 wt pct and iron (Fe): 5.8 wt pct] of particle size 45 to 60 ?m as precursor powder. Under the optimum process parameters, deposition leads to development of nano-borides (of chromium, Cr2B and nickel, Ni3B) dispersion in metastable and partly amorphous gamma nickel (?-Ni) matrix. The microhardness of the coating was significantly enhanced to 935 VHN as compared to 215 VHN of as-received substrate due to dispersion of nano-borides in grain refined and partly amorphous nickel matrix. Wear resistance property under fretting wear condition against WC indenter was improved in as-deposited layer (wear rate of 4.65 10-7 mm3/mm) as compared to as-received substrate (wear rate of 20.81 10-7 mm3/mm). The corrosion resistance property in a 3.56 wt pct NaCl solution was also improved.

Sharma, Prashant; Majumdar, Jyotsna Dutta

2013-01-01

50

Thermophysical properties of stainless steel foils  

Microsoft Academic Search

Evacuated panel superinsulations with very high center-of-panel thermal resistances are being developed for use in refrigerators\\/freezers. Attainment of high resistances relies upon the maintenance of low vacuum levels by the use of stainless steel vacuum jackets. However, the metal jackets also present a path for heat conduction around the high resistance fillers. This paper presents results of a study of

K. E. Wilkes; J. P. Strizak; F. J. Weaver; J. E. Besser; D. L. Smith

1997-01-01

51

Fatigue Properties of DLC-Coated Stainless Steel  

NASA Astrophysics Data System (ADS)

This study was conducted to investigate the effect of DLC (diamond-like carbon) coating on fatigue properties of austenitic stainless steel SUS304. For the DLC coating, UBMS (unbalanced magnetron sputtering) equipment was used. The generated surface layer of about 2 ?m thickness was composed of both the DLC layer possessing high hardness and a very thin intermediate layer to improve adhesion force between the DLC layer and the substrate. DLC coating, which was carried out at a relatively low temperature, had no influence on the microstructure so that the mechanical properties of the stainless steel were unchanged by the coating. The results of the plane-bending fatigue test showed that the DLC coating improved fatigue strength by 18%. From the results of detailed observation conducted on the fatigue fracture surface, it was suggested that the improvement in fatigue strength resulted from the suppression of fatigue crack initiation due to the surface layer, which had high adhesion force and strength.

Morita, Tatsuro; Tomita, Kouta; Kagaya, Chuji; Kumakiri, Tadashi; Ikenaga, Masaru

52

Mechanical and structural properties of similar and dissimilar steel joints  

SciTech Connect

The mechanical properties of specimens from similar and dissimilar weld joints were examined. A ferritic steel (St37-2) and an austenitic stainless steel (AISI 304) were joined by the gas tungsten arc weld (GTAW) process using an austenitic filler metal. Mechanical and metallographic properties of the specimens were obtained by means of microhardness testing, tensile testing, bending fatigue testing, and light optical and scanning electron microscopy. The highest microhardness values were recorded on the ferritic-austenitic dissimilar weld joint, whereas the highest tensile strength and bending fatigue life were obtained with the austenitic-austenitic joints. Ferritic and pearlitic structures were observed in the microstructure of the ferritic-ferritic joint. The microstructures of austenitic-austenitic and austenitic-ferritic joints showed small recrystallization grains in addition to the typical austenitic and ferritic structures. Scanning electron microscopy was used to observe the fracture surfaces of the specimens and the origins of the fatigue cracks.

Celik, A.; Alsaran, A.

1999-11-01

53

Thermomechanical processing and mechanical properties of hypereutectoid steels and cast irons  

SciTech Connect

Recent advances in metallurgy of hypereutectoid steels and cast irons show that unique properties, such ultrahigh hardness and strength, and superplasticity, are achievable. This book focuses on the mechanical properties of hypereutectoid steels and cast irons as influenced by thermomechanical processing and microstructure. Some topics covered are: (1) Hot workability of hypereutectoid tool steels; (2) Thermomechanical processing of austempered ductile iron: An overview; (3) Mechanical behavior of ultrahigh strength, ultrahigh carbon steel wire and rod; and (4) Tensile elongation behavior of fine-grained Fe-C alloys at elevated temperatures.

Lesuer, D.R.; Syn, C.K.; Sherby, O.D. (eds.)

1998-01-01

54

Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995  

SciTech Connect

Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.

Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)

1995-03-01

55

Friction Properties of Molybdenum Alloyed Steel at Elevated Temperatures  

SciTech Connect

The high-temperature properties of steel surface can be improved by molybdenum surface alloying. Molybdenzing was carried out on carbon steel in the multi-function double glow plasma surface alloying furnace. The friction and wear tests were conducted on a high temperature ball-on-disk tribometer under the temperature of 25 deg. C{approx}600 deg. C. The contents of alloy element varied with alloyed layer were detected by SEM attached with EDS. The molybdenized layer is composed of the deposited layer and diffused layer. The micro-hardness of alloyed layer decreases from HV650 on the top layer to HV240. The friction coefficient of molybdenized layer decreases from 0.5{approx}0.6 to 0.2{approx}0.3 and wear rate decreases by 20% at elevated temperature after molybdenizing.

Li Jianliang; Xiong Dangsheng [Department of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing, 210094 (China); Wu Hongyan [College of Math and Physics, Nanjing University of Information and Technology, Nanjing, 210044 (China)

2011-01-17

56

HYDROGEN EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEELS  

SciTech Connect

The effect of hydrogen on the fracture toughness properties of Types 304L, 316L and 21-6-9 forged stainless steels was investigated. Fracture toughness samples were fabricated from forward-extruded forgings. Samples were uniformly saturated with hydrogen after exposure to hydrogen gas at 34 MPa or 69 and 623 K prior to testing. The fracture toughness properties were characterized by measuring the J-R behavior at ambient temperature in air. The results show that the hydrogen-charged steels have fracture toughness values that were about 50-60% of the values measured for the unexposed steels. The reduction in fracture toughness was accompanied by a change in fracture appearance. Both uncharged and hydrogen-charged samples failed by microvoid nucleation and coalescence, but the fracture surfaces of the hydrogen-charged steels had smaller microvoids. Type 316L stainless steel had the highest fracture toughness properties and the greatest resistance to hydrogen degradation.

Morgan, M

2008-03-28

57

Structure and properties of dies obtained from scrap of 5KhNM and R6M5 steels by electroslag remelting  

SciTech Connect

It is known that in a number of cases cast dies of tool steels for hot working possess increased life. In the Lozovaya Forging and Machining Plant in electroslag remelting (ESR) of worn dies, a method is used making it possible to improve the quality of the cast blanks (dies) by additional alloying of them. A consumable composite electrode made of worn dies of 5KhNM steel reforged into bars and butt welded and scrap of R6M5 tool steel welded along the whole length of the main electrode in the form of a solid bar is used. Practically none of the chromium, molybdenum, tungsten, and vanadium additionally added in electroslag remelting burns off and therefore it is sufficient to add the expensive R6M5 steel scrap once. The improved characteristics of the steel are maintained in subsequent operations in the production chain. A comparative investigation was made of the character of the structure in the as-cast, annealed, hardened, and tempered conditions of 5KhNMVF steel produced by the above method and of 5KhNM steel produced by different methods.

Timchenko, E.I.; Semenova, L.M.; Berezkin, Yu.A.; Zaitseva, I.D.

1987-11-01

58

Properties of Pipe Steels Naturally Alloyed with Chromium and Nickel  

Microsoft Academic Search

tion of hydrogen by the metal in the process of corrosion, which considerably raises the resistance of the steel to hydrogen and corrosion cracking. When designing the steels we chose carbon steel 10 (GOST 1050) as a base widely used for seamless oil and gas pipes. We studied two variants of natural alloying (Table 1), namely, (I ) with 0.5%

V. N. Zikeev; E. K. Shafigin; G. G. Irzhov; Yu. D. Morozov; A. V. Nazarov

2001-01-01

59

Microstructure and mechanical properties of friction stir welded SAF 2507 super duplex stainless steel  

Microsoft Academic Search

The microstructure and mechanical properties of friction stir (FS) welded SAF 2507 super duplex stainless steel were examined. High-quality, full-penetration welds were successfully produced in the super duplex stainless steel by friction stir welding (FSW) using polycrystalline cubic boron nitride (PCBN) tool. The base material had a microstructure consisting of the ferrite matrix with austenite islands, but FSW refined grains

Y. S. Sato; T. W. Nelson; C. J. Sterling; R. J. Steel; C.-O. Pettersson

2005-01-01

60

Effect of deep cryogenic treatment on the mechanical properties of tool steels  

Microsoft Academic Search

The effect of deep cryogenic treatment (?196C) on the properties of some tool steels was studied by means of both field tests on real tools and laboratory tests. The execution of the deep cryogenic treatment on quenched and tempered high speed steel tools increases hardness, reduces tool consumption and down time for the equipment set up, thus leading to cost

A. Molinari; M. Pellizzari; S. Gialanella; G. Straffelini; K. H. Stiasny

2001-01-01

61

EFFECT OF POROSITY ON MECHANICAL PROPERTIES OF 8630 CAST STEEL  

E-print Network

EFFECT OF POROSITY ON MECHANICAL PROPERTIES OF 8630 CAST STEEL R.A. Hardin1 and C. Beckermann2 1, Mechanical and Industrial Engineering Dept. The University of Iowa Abstract Porosity is measured from between the indications on the radiographs and thickness of steel. Measured porosity dimensions from

Beckermann, Christoph

62

High-temperature mechanical properties of near-eutectoid steel  

NASA Astrophysics Data System (ADS)

The high-temperature mechanical properties of near-eutectoid steel were studied with a Gleeble-1500 simulation machine. Zero strength temperature (ZST), zero ductility temperature (ZDT), hot ductility curves, and strength curves were measured. Two brittle zones and one plastic zone were found in the temperature range from the melting point to 600C. Embrittlement in zone I is caused by the existence of liquid film along dendritic interfaces. Ductility loss in zone III mainly results from precipitates and inclusions as well as S segregation along grain boundaries. Pearlite transformation also accounts for ductility deterioration in the temperature range of 700-600C. Moreover, the straightening temperature of the test steel should be higher than 925C for avoiding the initiation and propagation of surface cracks in billets.

Fu, Jun; Wang, Fu-ming; Hao, Fang; Jin, Gui-xiang

2013-09-01

63

Influence of carbide and inclusion contents on the fatigue properties of high speed steels and tool steels  

Microsoft Academic Search

In this study the influence of carbide distribution, inclusion contents and the surface machining process on the fatigue properties of tool steels and high speed steels were investigated. Four different steels intended for cold work applications were included, of which three were powder metallurgically processed and one was conventionally ingot cast. One of the powder metallurgy steels was studied in

Fredrik Meurling; Arne Melander; Magnus Tidesten; Leif Westin

2001-01-01

64

History dependence of magnetomechanical properties of steel  

Microsoft Academic Search

Magnetomechanical measurements using a superconducting SQUID magnetic gradiometer and a tensile-testing machine have been performed on a variety of steel specimens to determine the change in magnetization due to applied stress and the possible application of the observed behavior as a new form of nondestructive evaluation in steel. This study builds on earlier related measurements.

F. Melquiond; A. Mouroux; J. Jouglar; P. L. Vuillermoz; H. Weinstock

1996-01-01

65

Mechanical Properties for Fracture Analysis of Mild Steel Storage Tasks  

Microsoft Academic Search

Mechanical properties of 1950's vintage, A285 Grade B carbon steels have been compiled for elastic-plastic fracture mechanics analysis of storage tanks (Lam and Sindelar, 1999). The properties are from standard Charpy V-notch (CVN), 0.4T planform Compact Tension (C(T)), and Tensile (T) specimens machined from archival steel from large water piping. The piping and storage tanks were constructed in the 1950s

R. L. Sindelar; P. S. Lam; G. R. Caskey

1999-01-01

66

Research Concerning The Mechanical And Structural Properties Of Warm Rolled Construction Carbon Steels  

SciTech Connect

Construction carbon steels represent an important steel class due to the large quantity in which it is produced. Generally, these steels are delivered in as-rolled or normalized condition heaving a ferrite-pearlite microstructure. For a given chemical composition, the mechanical characteristics of this microstructure are largely influenced by the grain size. Rolling is the deformation process which is most widely used for grain size refinement. Situated in the intermediate temperature range, warm-rolling presents certain advantages as compared to classical hot- or cold-working processes.The paper presents a study on the microstructure and mechanical properties of Ck15 carbon steel samples warm-rolled. After deformation, the microstructure was investigated by light microscopy. Hardness measurements were made on the section parallel to the rolling direction. The mechanical properties of the steel after warm-rolling were assessed by tensile and impact tests. Additional information concerning the fracture behavior of warm-rolled samples was obtained by examining the fracture surface by scanning electron microscopy. The microstructure of the steel proved to have good mechanical properties. By considering the technologic and energy aspects, the paper shows that warm-rolling can lead to the improvement of mechanical properties of construction carbon steels.

Medrea, C. [Technological Educational Institute of Piraeus, Depmartment of Physics, Chemistry and Materials Technology, 250 Thivon and P. Ralli Str, 12244, Aigaleo, Athens (Greece); Negrea, G.; Domsa, S. [Technical University of Cluj-Napoca, Faculty of Materials Science and Engineering, Cluj-Napoca (Romania)

2007-04-07

67

Microstructure and Mechanical Properties of a Nitride-Strengthened Reduced Activation Ferritic/Martensitic Steel  

NASA Astrophysics Data System (ADS)

Nitride-strengthened reduced activation ferritic/martensitic (RAFM) steels are developed taking advantage of the high thermal stability of nitrides. In the current study, the microstructure and mechanical properties of a nitride-strengthened RAFM steel with improved composition were investigated. Fully martensitic microstructure with fine nitrides dispersion was achieved in the steel. In all, 1.4 pct Mn is sufficient to suppress delta ferrite and assure the steel of the full martensitic microstructure. Compared to Eurofer97, the steel showed similar strength at room temperature but higher strength at 873 K (600 C). The steel exhibited very high impact toughness and a low ductile-to-brittle transition temperature (DBTT) of 243 K (-30 C), which could be further reduced by purification.

Zhou, Qiangguo; Zhang, Wenfeng; Yan, Wei; Wang, Wei; Sha, Wei; Shan, Yiyin; Yang, Ke

2012-12-01

68

Wetting and mechanical properties, a case study: Liquid metal embrittlement of a martensitic steel by liquid lead and other liquid metals  

Microsoft Academic Search

We present experimental results of tensile and fatigue properties of the T91 (a 9% Cr martensitic steel) in a stagnant molten\\u000a metallic bath (Pb, Pb-Bi or Sn for instance). Under particular experimental conditions, the tensile tests revealed an instantaneous\\u000a embrittlement of the material, more pronounced at low temperature, that disappears as the temperature is raised above 450C.\\u000a This behavior is

A. Legris; J.-B. Vogt; A. Verleene; I. Serre

2005-01-01

69

Aging properties of vanadium-bearing high manganese stainless steel  

SciTech Connect

Strengthening of austenitic ({gamma}) stainless steel is of great interest to utilization for the structural component. Strengthening of the steel is attained by a combination of following mechanisms such as solution strengthening, strengthening by grain size effect, strain hardening, and precipitation hardening. A selection for the strengthening of {gamma} steel is precipitation hardening due to carbides, nitrides, and intermetallic phases, by which both high strength and low permeability of {gamma} steel may be satisfied. Among Mo, Ti, V, and Nb carbides, it is known that vanadium carbide is considered to be potent contributor to hardening because it precipitates finely in the matrix and grow relatively slower. However, carbide precipitation hardening behavior of highly alloyed {gamma} stainless steel has not been much studied. In this paper, hardening behavior of the vanadium added, low permeability {gamma} stainless steel, Fe-Cr-6Ni-10Mn-V-C, was investigated focusing on the microstructural change and compositional aspects.

Haruna, Y. [Sanyo Special Steel Co., Ltd., Himeji (Japan). Technological Research Lab.] [Sanyo Special Steel Co., Ltd., Himeji (Japan). Technological Research Lab.; Yamamoto, A.; Tsubakino, H. [Himeji Inst. of Tech. (Japan). Dept. of Materials Science and Engineering] [Himeji Inst. of Tech. (Japan). Dept. of Materials Science and Engineering

1997-11-01

70

Improved Life of Die Casting Dies of H13 Steel by Attaining Improved Mechanical Properties and Distortion Control During Heat Treatment  

SciTech Connect

The ultimate goal of this project is to increase die casting die life by using fast enough quenching rates to obtain good toughness and fatigue resistance in premium grade H-13 steel dies. The main tasks of the project were to compile a database on physical and mechanical properties of H-13; conduct gas quenching experiments to determine cooling rates of dies in difference vacuum furnaces; measure the as-quenched distortion of dies and the residual stresses; generate finite element analysis models to predict cooling rates, distortion, and residual stress of gas quenched dies; and establish rules and create PC-based expert system for prediction of cooling rates, distortion, and residual stress in vacuum/gas quenched H-13 dies. Cooling curves during gas quenching of H-13 blocks and die shapes have been measured under a variety of gas pressure. Dimensional changes caused by the gas quenching processes have been determined by accurate mapping of all surfaces with coordinate measuring machines before and after the quench. Residual stresses were determined by the ASTM E837 hole-drilling strain gage method. To facilitate the computer modeling work, a comprehensive database of H-13 mechanical and physical properties has been compiled. Finite element analysis of the heat treated shapes has been conducted using the TRAST/ABAQUS codes. There is a good fit between the predicted and measured distortion contours. However, the magnitude of the predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required before it can be used to predict distortion and residual stress in a quantitative manner. This last step is a prerequisite to generating rules for a reliable expert system.

J. F. Wallace; D. Schwam

1998-10-01

71

Mechanical Properties and Microstructural Evolution of Welded Eglin Steel  

NASA Astrophysics Data System (ADS)

Eglin steel is a new ultra-high strength steel that has been developed at Eglin Air Force Base in the early 2000s. This steel could be subjected to a variety of processing steps during fabrication, each with its own thermal history. This article presents a continuous cooling transformation diagram developed for Eglin steel to be used as a guideline during processing. Dilatometry techniques performed on a Gleeble thermo-mechanical simulator were combined with microhardness results and microstructural characterization to develop the diagram. The results show that four distinct microstructures form within Eglin steel depending on the cooling rate. At cooling rates above about 1 C/s, a predominately martensitic microstructure is formed with hardness of 520 HV. Intermediate cooling rates of 1 C/s to 0.2 C/s produce a mixed martensitic/bainitic microstructure with a hardness that ranges from 520 - 420 HV. Slower cooling rates of 0.1 C/s to 0.03 C/s lead to the formation of a bainitic microstructure with a hardness of 420 HV. The slowest cooling rate of 0.01 C/s formed a bainitic microstructure with pearlite at the prior austenite grain boundaries. A comprehensive study was performed to correlate the mechanical properties and the microstructural evolution in the heat affected zone of thermally simulated Eglin steel. A Gleeble 3500 thermo-mechanical simulator was used to resistively heat samples of wrought Eglin steel according to calculated thermal cycles with different peak temperatures at a heat input of 1500 J/mm. These samples underwent mechanical testing to determine strength and toughness, in both the `as-simulated' condition and also following post-weld heat treatments. Mechanical testing has shown that the inter-critical heat affected zone (HAZ) has the lowest strength following thermal simulation, and the fine-grain and coarse-grain heat affected zone having an increased strength when compared to the inter-critical HAZ. The toughness of the heat affected zone in the as-simulated condition is lower than that of the base metal. Post-weld heat treatments (PWHT) have been shown to increase the toughness of the HAZ, but at the expense of strength. In addition, certain combinations of PWHTs within specific HAZ regions have exhibited low toughness caused by tempered martensite embrittlement or intergranular failure. Synchrotron X-ray diffraction data has shown that Eglin steel has retained austenite in the fine-grain HAZ in the as-simulated condition. In addition, alloy carbides (M23C 6, M2C, M7C3) have been observed in the diffraction spectra for the fine-grain and coarse-grain HAZ following a PWHT of 700 C / 4 hours. A first attempt at thermodynamic modeling has been undertaken using MatCalc to try to predict the evolution of carbides in the HAZ following thermal cycling and PWHT.

Leister, Brett M.

72

Steel Reoxidation by Gunning Mass and Tundish Slag  

NASA Astrophysics Data System (ADS)

Steel reoxidation in the tundish has a significant influence on the steel cleanliness and therefore on the mechanical properties of the final product. In the present work, the steel reoxidation by two types of gunning mass (GM), viz. magnesia- and alumina-based GM, and two types of tundish slag, viz. lime-alumina-silica and lime-alumina slags, has been investigated. The evolution of the steel composition during the test was analyzed and predicted based on thermodynamic and kinetic considerations. The calculated steel composition agrees well with measured values, when assuming the mass transfer in slag phase limits the reoxidation reactions. The oxidation capacity of the gunning mass and tundish slag is quantified by calculating the oxygen amount supplied from the GM and the slag to the steel phase. It was found that compared to alumina GM, magnesia GM exhibits a stronger oxidation capacity due to its higher content of reducible oxides (10 wt pct SiO2 + 6 wt pct FeO). Compared to lime-alumina-silica tundish slag, lime-alumina slag (with more FeO + MnO contents) provides more oxygen to the molten steel in the present experimental conditions and consequently shows a stronger oxidation capacity.

Yan, Pengcheng; Arnout, Sander; Van Ende, Marie-Aline; Zinngrebe, Enno; Jones, Tom; Blanpain, Bart; Guo, Muxing

2015-01-01

73

Corrosion Inhibition of Steel by Bacteria  

Microsoft Academic Search

Mild steel was exposed to Pseudomonas sp. S9 or Serratia marcescens in synthetic seawater. An increase in corrosion resistance over that i natural seawater was monitored by electrochemical techniques. Biological analyses were performed to characterize the system. The inhibition effect also was observed when mild steel was coated with bacteria and then immersed in synthetic seawater. When specimens coated with

G. Hernandez; V. Kucera; D. Thierry; M. Hermansson; A. Pedersen

1994-01-01

74

Effect of Heat Treatment on the Microstructure and Mechanical Properties of Stainless Steel 316L Coatings Produced by Cold Spray for Biomedical Applications  

NASA Astrophysics Data System (ADS)

In this study, the effects of heat treatment on the microstructure and mechanical properties of cold sprayed stainless steel 316L coatings using N2 and He as propellant gases were investigated. Powder and coating characterizations, including coating microhardness, coating porosity, and XRD phase analysis were performed. It was found that heat treatment reduced porosity, improved inter-particle bonding, and increased ductility. XRD results confirmed that no phase transformation occurred during deposition. Significant increase in UTS and ductility was observed for the annealed specimens obtained with nitrogen propellant, whereas little changes were observed for the helium propellant produced specimen.

AL-Mangour, Bandar; Vo, Phuong; Mongrain, Rosaire; Irissou, Eric; Yue, Stephen

2014-04-01

75

Effect of oxide phase on the tribological properties of high-chromium steels  

NASA Astrophysics Data System (ADS)

The effect of dispersed oxide phases of Y2O3-TiO2 type on the wear rate and the friction coefficient of the high-chromium martensitic 18Kh12V2 and ferritic 01Kh13V2 steels upon sliding friction in pair with the 40Kh12 steel has been studied. The structure of these materials has been analyzed by metallographic and electron-microscopic methods. It has been shown that the presence of about 0.5% dispersed oxide particles, including nanosized ones, in the structure of the ferritic 01Kh13V2 steel exerts a complex influence on the wear resistance of this steel. Upon dry friction under the conditions of adhesive wear, the 01Kh12V2 steel alloyed with oxides is characterized by a low wear resistance. It is caused by an increased brittleness of the steel, which activates the processes of seizure and deep tearing at the friction surface of the steel. In the case of lubricated friction (boundary friction regime), dispersed oxide phases exert a great positive influence on the wear resistance of the steel. The wear rate of the oxide-strengthened ferritic steel in this case is about twice as low as that of the steel nonalloyed with oxides. It is caused by the formation of numerous pores in the surface layer of the alloyed steel in place of spalled oxides. The formation of pores helps better retention of a lubricant in the friction zone (the effect of self-lubrication), which decreases the probability of adhesive inter-action between the contacting steel surfaces. It has been found out that the alloying of a high-chromium martensitic 18Kh12V2 steel with a small amount (0.3%) of oxides of the Y2O3 + TiO2 type does not exert a noticeable influence on the tribological properties of the steel under consideration. The oxide phase does not affect noticeably the magnitude of the friction coefficient of the steels tested.

Korshunov, L. G.; Sagaradze, V. V.; Kataeva, N. V.; Chernenko, N. L.; Ageev, V. S.; Danil'Chenko, V. E.

2011-08-01

76

Effect of tin addition on the microstructure and properties of ferritic stainless steel  

NASA Astrophysics Data System (ADS)

This article reports the effects of Sn on the inclusions as well as the mechanical properties and hot workability of ferritic stainless steel. Precipitation phases and inclusions in Sn-bearing ferritic stainless steel were observed, and the relationship between the workability and the microstructure of the steel was established. Energy-dispersive X-ray spectroscopic analysis of the steel reveals that an almost pure Sn phase forms and MnS-Sn compound inclusions appear in the steel with a higher Sn content. Little Sn segregation was observed in grain boundaries and in the areas around sulfide inclusions; however, the presence of Sn does not adversely affect the workability of the steel containing 0.4wt% Sn. When the Sn content is 0.1wt%-0.4wt%, Sn improves the tensile strength and the plastic strain ratio and also improves the plasticity with increasing temperature. A mechanism of improving the workability of ferritic stainless steel induced by Sn addition was discussed: the presence of Sn lowers the defect concentration in the ultra-pure ferritic lattice and the good distribution of tin in the lattice overcomes the problem of hot brittleness that occurs in low-carbon steel as a result of Sn segregation.

Li, Yang; Han, Ji-peng; Jiang, Zhou-hua; He, Pan

2015-01-01

77

Microstructure and Corrosion Properties of AlCoCrFeNi High Entropy Alloy Coatings Deposited on AISI 1045 Steel by the Electrospark Process  

NASA Astrophysics Data System (ADS)

Electrospark deposition (ESD) was employed to clad the AlCoCrFeNi high-entropy alloy (HEA) on AISI 1045 carbon steel. The relationship between the microstructure and corrosion properties of the HEA-coated specimens was studied and compared with that of the copper-molded cast HEA material. Two major microstructural differences were found between the cast HEA material and the HEA coatings. First, the cast material comprises both columnar and equiaxed crystals with a columnar-to-equiaxed transition (CET), whereas the HEA coatings consist of an entirely columnar crystal structure. The CET phenomenon was analyzed based on Hunt's criterion. Second, unlike the cast HEA material, there was no obvious Cr-rich interdendritic segregation and nano-sized precipitate distributed within the dendrites of the HEA coating. With regard to corrosion properties, the corrosion current of the HEA-coated specimen was significantly lower than for the 1045 steel and the cast HEA material. This was attributed to the ESD specimen having a relatively high Cr oxide and Al oxide content at the surface. Moreover, for the ESD specimen, the absence of Cr-rich interdendritic phase and second-phase precipitation resulted in a relatively uniform corrosion attack, which is different from the severe galvanic corrosion attack that occurred in the cast specimen.

Li, Q. H.; Yue, T. M.; Guo, Z. N.; Lin, X.

2013-04-01

78

Influence of plastic deforamtion by shot peening and of cyclic loading on the properties of the surface layer of 30KhGSN2A steel  

Microsoft Academic Search

1.The high effectiveness of repeated surface hardening, revealed in an increase in cyclic life of the high-strength steel, is caused by the high amount and depth of penetration of the first order residual compressive stresses (in comparison with the first peening) and by the significant changes in phase composition and fine structure of the surface layer of the material.2.Cyclic loading

G. N. Kravchenko; V. V. Alekseev

1986-01-01

79

IRRADIATION CREEP AND MECHANICAL PROPERTIES OF TWO FERRITIC-MARTENSITIC STEELS IRRADIATED IN THE BN-350 FAST REACTOR  

SciTech Connect

Russian ferritic/martensitic steels EP-450 and EP-823 were irradiated to 20-60 dpa in the BN-350 fast reactor in the form of pressurized creep tubes and small rings used for mechanical property tests. Data derived from these steels serves to enhance our understanding of the general behavior of this class of steels. It appears that these steels exhibit behavior that is very consistent with that of Western steels. Swelling is relatively low at high neutron exposure and confined to temperatures less then 420 degrees C, but may be camouflaged somewhat by precipitation-related densification. The irradiation creep studies confirm that the creep compliance of F/M steels is about one-half that of austenitic steels, and that the loss of strength at test temperatures above 500 degrees C is a problem generic to all F/M steels. This conclusion is supported by post-irradiation measurement of short-term mechanical properties. At temperatures below 500 degrees C both steels retain their high strength (yield stress 0.2=550-600 MPa), but at higher test temperatures a sharp decrease of strength properties occurs. However, the irradiated steels still retain high post-irradiation ductility at test temperatures in the range of 20-700 degrees C.

Porollo, S. I.; Konobeev, Yu V.; Dvoriashin, A. M.; Budylkin, N. I.; Mironova, E. G.; Leontyeva-Smirnova, M. V.; Loltukhovsky, A. G.; Bochvar, A. A.; Garner, Francis A.

2002-09-01

80

Effect of aging on properties of pressure vessel steels  

SciTech Connect

Manganese-molybdenum-nickel steels are used in nuclear pressure vessels operating at temperatures up to 350/sup 0/C. The effects of thermal ageing in the temperature range 300-550/sup 0/C for durations up to 2 x 10/sup 4/ h have been studied in conventionally quenched and tempered and simulated heat-affected-zone (HAZ) microstructural conditions. Quantitative fractography and Auger spectroscopy have been used to relate changes in mechanical properties with changes in fracture mode and grain boundary chemistry. Aging increases the ductile-brittle transition temperature by an amount dependent on material, prior heat treatment, aging temperature and time. Embrittlement is associated with segregation of phosphorus to grain boundaries and is modelled using McLean's approach to equilibrium segregation.

Druce, S.G.; Gage, G.; Jordan, G.

1986-04-01

81

Fatigue Property of Stainless Steel FES Electrode in Hanks' Solution  

Microsoft Academic Search

Fatigue property of the wire rope with 19 strands used as an FES electrode was investigated. The wire rope was made of high manganese high nitrogen austenitic stainless steel. Fatigue life of the wire rope in Hanks' solution at 310 K was evaluated using a dual-driven rotating-bending fatigue machine. Each wire of the rope was worn out and the cross

Y. Iguchi; T. Narushima; K. Suzuki; S. Yoshida; M. Watanabe; T. Kinami; C. Ouchi

82

Microstructure and mechanical properties of quenched and tempered 300M steel  

NASA Technical Reports Server (NTRS)

Type 300M steel, which is being used for the landing gear on the space shuttle orbiter, was subjected to a wide range of quenched and tempered heat treatments. The plane-strain fracture toughness and the tensile ultimate and yield strengths were evaluated. Cryogenic mechanical properties were obtained for conventionally heat-treated steel. The microstructure of all heat-treated test coupons was studied both optically and by transmission electron microscopy. Fracture surfaces were studied by means of scanning electron microscopy. Results indicate that substantial improvement in toughness with no loss in strength can be accomplished in quenched and tempered steel by austenitizing at 1255 K or higher. Low fracture toughness in conventionally austenitized 300M steel (1144 K) appears to be caused by undissolved precipitates, seen both in the submicrostructure and on the fracture surface, which promote failure by quasi-cleavage. The precipitates appeared to dissolve in the range 1200 to 1255 K.

Youngblood, J. L.; Raghavan, M.

1978-01-01

83

MICROSTRUCTURE AND MECHANICAL PROPERTY PERFORMANCE OF COMMERCIAL GRADE API PIPELINE STEELS IN HIGH PRESSURE GASEOUS HYDROGEN  

SciTech Connect

The continued growth of the world s developing countries has placed an ever increasing demand on traditional fossil fuel energy sources. This development has lead to increasing research and development of alternative energy sources. Hydrogen gas is one of the potential alternative energy sources under development. Currently the most economical method of transporting large quantities of hydrogen gas is through steel pipelines. It is well known that hydrogen embrittlement has the potential to degrade steel s mechanical properties when hydrogen migrates into the steel matrix. Consequently, the current pipeline infrastructure used in hydrogen transport is typically operated in a conservative fashion. This operational practice is not conducive to economical movement of significant volumes of hydrogen gas as an alternative to fossil fuels. The degradation of the mechanical properties of steels in hydrogen service is known to depend on the microstructure of the steel. Understanding the levels of mechanical property degradation of a given microstructure when exposed to hydrogen gas under pressure can be used to evaluate the suitability of the existing pipeline infrastructure for hydrogen service and guide alloy and microstructure design for new hydrogen pipeline infrastructure. To this end, the 2 Copyright 2010 by ASME microstructures of relevant steels and their mechanical properties in relevant gaseous hydrogen environments must be fully characterized to establish suitability for transporting hydrogen. A project to evaluate four commercially available pipeline steels alloy/microstructure performance in the presences of gaseous hydrogen has been funded by the US Department of Energy along with the private sector. The microstructures of four pipeline steels were characterized and then tensile testing was conducted in gaseous hydrogen and helium at pressures of 800, 1600 and 3000 psi. Based on measurements of reduction of area, two of the four steels that performed the best across the pressure range were selected for evaluation of fracture and fatigue performance in gaseous hydrogen at 800 and 3000 psi. This paper will describe the work performed on four commercially available pipeline steels in the presence of gaseous hydrogen at pressures relevant for transport in pipelines. Microstructures and mechanical property performances will be compared. In addition, recommendations for future work related to gaining a better understanding of steel pipeline performance in hydrogen service will be discussed.

Stalheim, Mr. Douglas [DGS Metallurgical Solutions Inc; Boggess, Todd [Secat; San Marchi, Chris [Sandia National Laboratories (SNL); Jansto, Steven [Reference Metals Company; Somerday, Dr. B [Sandia National Laboratories (SNL); Muralidharan, Govindarajan [ORNL; Sofronis, Prof. Petros [University of Illinois

2010-01-01

84

The mechanical properties of high-strength steel weldments  

Microsoft Academic Search

In order to develop good mechanical properties in highstrength weldments, selection of a welding process, weld consumables,\\u000a and postweld heat treatment compatible with the intended service is of major importance. This paper illustrates how these\\u000a selections can influence the properties of the weld metal, heataffected zone and base metal for six highstrength pressure\\u000a vessel steels. In each case, the balance

A. W. Pense

1983-01-01

85

The effect of surface indications on the tensile properties of cast steel  

NASA Astrophysics Data System (ADS)

The objective of this thesis was to study the effect of surface indications on the tensile properties of cast steel. Four cast steel grades were selected for evaluation; these grades include three carbon and low alloy steels (110/80, 165/135, and Eglin) and one high alloy steel (CF8M). Using these steels, tensile specimens were produced, inspected via MT/PT, categorized by surface indications (as-cast or machined), and tested. Bars with natural surface indications were tensile tested and the properties recorded. The presence of a ? inch, ? inch, or inch flat-bottomed hole drilled through half the thickness mimicked a similar nonlinear worse-case scenario indication. The inch indication resulted in an ultimate tensile strength loss ranging from 21.5% to 36.0%, with the more ductile materials being impacted least. The percent elongation loss ranged from 38.5% to 69.9%, with the majority of the alloys showing an approximate 60 percent loss in elongation. The modulus decrease ranged from 2.9% to 17.5%. These results were modeled using ANSYS to observe capability in predicting a decrease in properties. The resulting decrease in properties matched the experimental data to an accuracy of 3+/-11%. The results provide a previously undocumented relationship between indication size and tensile properties.

Hamby, Jeff

86

Adhesion and wear properties of TiN films deposited on martensitic stainless steel and Stellite by reactive magnetron sputter ion plating  

NASA Astrophysics Data System (ADS)

TiN films were deposited onto the turbine blade materials, AISI 403 martensitic stainless steel and Stellite 6B, using reactive magnetron sputter ion plating. The hardness of the TiN film increases with the residual compressive stress and has a maximum value of 3400 kg/mm 2 at the substrate bias of about -75 V. In the scratch adhesion test, the critical loads for cohesive failure and adhesive failure are sensitively governed by the film hardness. The wear rate decreases with increasing hardness and has a minimum value at about -75 V. The ion plated TiN has a superior wear resistance than the bare Stellite 6B and AISI 403 martensitic stainless steel.

Lee, Min Ku; Kim, Whung Whoe; Kim, Joung Soo; Lee, Won Jong

1998-03-01

87

Impact Welding of Aluminum to Copper and Stainless Steel by Vaporizing Foil Actuator: Effect of Heat Treatment Cycles on Mechanical Properties and Microstructure  

NASA Astrophysics Data System (ADS)

This work studies the mechanical property effect of microstructure on impact welds of aluminum alloy AA6061 with both copper alloy Cu 110 and stainless steel AISI 304. AA6061-T6 and T4 temper aluminum sheets of 1 mm thickness were launched toward copper and stainless steel targets using the vaporizing foil actuator technique. Flyer plate velocities, measured via photonic Doppler velocimetry, were observed to be approximately 800 m/s. The welded aluminum-copper samples were subjected to instrumented peel testing, microhardness testing, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The welded joints exhibited cracks through their continuous intermetallic layers. The cracks were impeded upon encountering a ductile metallic wave. The welds created with T6 temper flyer sheets were found to have smaller intermetallic-free and wavy interface regions as compared to those created with T4 temper flyer sheets. Peel strength tests of the two weld combinations resulted in failure along the interface in the case of the T6 flyer welds, while the failure generally occurred in the parent aluminum for the T4 temper flyer welds. Half of the T4 flyer welds were subjected to aging for 18 h at 433 K (160 C) to convert the aluminum sheet to the T6 condition. Although the aged flyer material did not attain the hardness of the as-received T6 material, it was found to be significantly stronger than the T4 material. These welds retained their strength after the aging process, and diffusion across the interface was minimal. The welded aluminum-stainless steel samples were analyzed on a more basic level than aluminum-copper samples, but were found to exhibit similar results.

Vivek, Anupam; Hansen, Steven; Benzing, Jake; He, Mei; Daehn, Glenn

2014-06-01

88

A discussion on improving hydration activity of steel slag by altering its mineral compositions.  

PubMed

This study aims to investigate the ways to improve the cementitious properties of steel slag. The results show that the cementitious phase of steel slag is composed of silicate and aluminate, but the large particles of these phases make a very small contribution to the cementitious properties of steel slag. RO phase (CaO-FeO-MnO-MgO solid solution), Fe(3)O(4), C(2)F and f-CaO make no contribution to the cementitious properties of steel slag. A new kind of steel slag with more cementitious phase and less RO phase can be obtained by removing some large particles. This new steel slag possesses better cementitious properties than the original steel slag. The large particles can be used as fine aggregates for concrete. Adding regulating agent high in CaO and SiO(2) during manufacturing process of steel slag to increase the cementitious phase to inert phase ratio is another way to improve its cementitious properties. The regulating agent should be selected to adapt to the specific steel slag and the alkalinity should be increased as high as possible on the premise that the f-CaO content does not increase. The cooling rate should be enhanced to improve the hydration activity of the cementitious phase at the early ages and the grindability of steel slag. PMID:21168967

Wang, Qiang; Yan, Peiyu; Feng, Jianwen

2011-02-28

89

Effects of hydrogen on the mechanical properties of oxide dispersion strengthening steels  

NASA Astrophysics Data System (ADS)

The effects of hydrogen on the mechanical properties of oxide dispersion strengthened (ODS) steels were investigated by means of tensile tests at room temperature. Cathodic hydrogen charging was carried out before and during deformation in a sulfuric acid solution by imposing a constant current density in the range of 100 to -520 A/m 2. With increasing charging current density, the loss of ductility increased accompanied by a change in fracture mode from ductile to intergranular fracture. The critical hydrogen concentration in ODS steels required to transition from ductile to brittle fracture was in the range of 10-12 wppm, which approximately 10 times larger than that of a 9Cr-2W martensitic steel. In addition, the susceptibility to hydrogen embrittlement of ODS steels strongly depended on specimen sampling orientation.

Lee, J. S.; Kimura, A.; Ukai, S.; Fujiwara, M.

2004-08-01

90

Surface properties of nitrided layer on AISI 316L austenitic stainless steel produced by high temperature plasma nitriding in short time  

NASA Astrophysics Data System (ADS)

It has generally been believed that the formation of the S phase or expanded austenite ?N with enough thickness depends on the temperature (lower than 480 C) and duration of the process. In this work, we attempt to produce nitrogen expanded austenite layer at high temperature in short time. Nitriding of AISI 316L austenitic stainless steel was carried out at high temperatures (>520 C) for times ranging from 5 to 120 min. The microstructures, chemical composition, the thickness and the morphology of the nitrided layer, as well as its surface hardness, were investigated using X-ray diffraction, X-ray photoelectron spectroscopy, optical microscopy, scanning electron microscopy, and microhardness tester. The corrosion properties of the untreated and nitrided samples were evaluated using anodic polarization tests in 3.5% NaCl solution. The results confirmed that nitrided layer was shown to consist of ?N and a small amount of free-CrN and iron nitrides. High temperature plasma nitriding not only increased the surface hardness but also improved the corrosion resistance of the austenitic stainless steel, and it can critically reduce processing time compared with low temperature nitriding.

Li, Yang; Wang, Zhuo; Wang, Liang

2014-04-01

91

A Novel Ni-Containing Powder Metallurgy Steel with Ultrahigh Impact, Fatigue, and Tensile Properties  

NASA Astrophysics Data System (ADS)

The impact toughness of powder metallurgy (PM) steel is typically inferior, and it is further impaired when the microstructure is strengthened. To formulate a versatile PM steel with superior impact, fatigue, and tensile properties, the influences of various microstructures, including ferrite, pearlite, bainite, and Ni-rich areas, were identified. The correlations between impact toughness with other mechanical properties were also studied. The results demonstrated that ferrite provides more resistance to impact loading than Ni-rich martensite, followed by bainite and pearlite. However, Ni-rich martensite presents the highest transverse rupture strength (TRS), fatigue strength, tensile strength, and hardness, followed by bainite, pearlite, and ferrite. With 74 pct Ni-rich martensite and 14 pct bainite, Fe-3Cr-0.5Mo-4Ni-0.5C steel achieves the optimal combination of impact energy (39 J), TRS (2170 MPa), bending fatigue strength at 2 106 cycles (770 MPa), tensile strength (1323 MPa), and apparent hardness (38 HRC). The impact energy of Fe-3Cr-0.5Mo-4Ni-0.5C steel is twice as high as those of the ordinary high-strength PM steels. These findings demonstrate that a high-strength PM steel with high-toughness can be produced by optimized alloy design and microstructure.

Wu, Ming-Wei; Shu, Guo-Jiun; Chang, Shih-Ying; Lin, Bing-Hao

2014-08-01

92

Charpy impact properties of 9CrODS ferritic steels  

NASA Astrophysics Data System (ADS)

The toughness of 9CrODS steels was evaluated by using an instrumented Charpy impact test machine, focusing on various processes such as hot-forging and hot-rolling. The upper-shelf energy (USE) of the hot-forged specimens is superior; their full-size USE converted from the miniaturized specimen lies within the published data for ODS steels, whereas hot-rolling leads to poor toughness. The total absorbed energy was separated into the energies for crack initiation and propagation. The hot-forged 9CrODS steels provide similar crack initiation energy to ferritic/martensitic steels (FMSs); their low absorbed energy is attributed to a limited amount of crack propagation energy induced by plastic deformation.

Izawa, Wataru; Ukai, Shigeharu; Oono, Naoko; Hayashi, Shigenari; Sakamura, Takashi; Kohno, Yutaka; Ohtsuka, Satoshi; Kaito, Takeji

2013-11-01

93

Effect of rolling with shear on the properties of steel 08G2S rods and wire  

NASA Astrophysics Data System (ADS)

The hereditary effect of the structure of a wire rod on the structure and physicomechanical properties of the steel 08G2S wire produced by rolling with shear is studied in comparison with the wire produced according to the standard technology in OAO Metal Steel Krivoi Rog.

Pashinskaya, E. G.; Tolpa, A. A.; Myshlyaev, M. M.; Grishaev, V. V.; Zavdoveev, A. V.

2011-11-01

94

Mechanical properties and microstructures of China low activation martensitic steel compared with JLF-1  

NASA Astrophysics Data System (ADS)

The tensile and impact properties of CLAM steel are compared to those of JLF-1 steel. Tensile testing revealed that the ultimate and yield strengths of the CLAM steel are 670 MPa and 512 MPa at room temperature, and 373 MPa and 327 MPa at 873 K, respectively. These values are higher than those measured for JLF-1. The ductile-to-brittle transition temperature (DBTT) of CLAM was found to be 171 K using one-third size Charpy V-notch specimens, which is 16 K lower than that of JLF-1. Microstructural analysis by SEM and TEM indicated that the prior austenite grain size and lath width for CLAM are smaller than those for JLF-1. The finer grain and lath structure is considered to be one of the main reasons for the higher strength and lower DBTT of the CLAM steel.

Li, Y.; Huang, Q.; Wu, Y.; Nagasaka, T.; Muroga, T.

2007-08-01

95

Dynamic Material Property Measurement of Steel Thin Sheets using Laser-Based Ultrasonics  

NASA Astrophysics Data System (ADS)

A material property measurement system for steel sheets using laser-based ultrasonics was developed. The system consists of a pulsed Nd:YAG laser for ultrasonic generation and multi-channel interferometer coupled with a CW single frequency laser for ultrasonic detection. The system can measure the frequency of the S1 Lamb wave mode of zero group velocity (S1f) as well as the longitudinal resonance frequencies without ablative damage to the steel surface. It was confirmed that Poisson's ratio could be directly obtained by combining the measured S1f value and the longitudinal resonance frequencies. To evaluate the applicability of this system in an actual steel production setting, the system was installed in hot rolling pilot plant that produces steel samples. As a result, it was demonstrated that the system can measure dynamic changes in Poisson's ratio values within steel sheets, even in the hot rolling pilot plant environment. Material property data, such as Poisson's ratio, during the thin sheet production process will be very useful for manufacturing high value-added steel, such as sheets with uniform quality.

Nagata, Y.; Yamada, H.; Hashiguchi, S.; Lim, C. S.; Park, H. C.; Huh, H. J.; Kang, M. K.; Oh, K. J.

2014-06-01

96

The microstructure and properties of a quenched and tempered low-carbon-manganese-niobium steel  

Microsoft Academic Search

The effects of rolling parameters (deformation schedule and finishing temperature), cooling rate (direct quench and air cool), and heat treatment have been investigated for a low carbon-manganese-niobium steel. Microstructure was characterized by optical and transmission electron microscopy, and correlated with tensile and impact properties. The best combination of strength and toughness was obtained by controlled rolling low in the austenite

J. D. Boyd

1976-01-01

97

Effect of transport properties of fiber types on steel reinforcement corrosion  

Microsoft Academic Search

This study investigated the transport properties of fiber types in concrete to evaluate their effect on the corrosion of steel reinforcement. The fibers used in this research are polypropylene (PP), polyvinyl alcohol (PVA), and hooked-end steel fiber (Steel). The addition of PVA fibers having relatively good resistance to transport properties indicated the best resistance to the initiation time of corrosion.

B. Kim; A. J. Boyd; J.-Y. Lee

2011-01-01

98

An investigation into the protective properties of a VCI modified acrylic film for protective steel applications  

SciTech Connect

This paper describes the protective properties of water-based VCI (Volatile Corrosion Inhibitors) modified acrylic film intended for the temporary protection from corrosion of carbon steel equipment during transportation and storage in the open air. The protective properties of water-based VCI modified acrylic film were studied by means of electrochemical methods and compared under outdoor atmospheric industrial conditions. The polarization curves showed that the VCI compound investigated was of the anodic type. The steel panels coated by the water-based VCI modified acrylic system of various film thickness (0--25 microns) were examined under atmospheric oil refinery industrial conditions. This examination showed that these films protect the carbon steel surfaces for at least 10 months.

Groysman, A. [Oil Refineries Ltd., Haifa (Israel)

1998-12-31

99

Evaluation of Microstructure and Mechanical Properties in Dissimilar Austenitic/Super Duplex Stainless Steel Joint  

NASA Astrophysics Data System (ADS)

To study the effect of chemical composition on microstructural features and mechanical properties of dissimilar joints between super duplex and austenitic stainless steels, welding was attempted by gas tungsten arc welding process with a super duplex (ER2594) and an austenitic (ER309LMo) stainless steel filler metal. While the austenitic weld metal had vermicular delta ferrite within austenitic matrix, super duplex stainless steel was mainly comprised of allotriomorphic grain boundary and Widmansttten side plate austenite morphologies in the ferrite matrix. Also the heat-affected zone of austenitic base metal comprised of large austenite grains with little amounts of ferrite, whereas a coarse-grained ferritic region was observed in the heat-affected zone of super duplex base metal. Although both welded joints showed acceptable mechanical properties, the hardness and impact strength of the weld metal produced using super duplex filler metal were found to be better than that obtained by austenitic filler metal.

Rahmani, Mehdi; Eghlimi, Abbas; Shamanian, Morteza

2014-10-01

100

Creep-fatigue properties of advanced 316-steel for FBR structures  

SciTech Connect

This paper describes the creep-fatigue, fatigue and creep rupture properties of advanced 316 steel (316FR) at high temperature. 316FR steel showed excellent creep-fatigue lives which were superior at longer strain hold time conditions compared with conventional type 316, 304 stainless steels. 316 FR steel also indicated higher creep rupture strength and ductility than conventional steels. This paper also describes the effect of microstructure of 316 FR steel on creep-fatigue strength. Finally, the applicability of 316 FR steel for two types of creep-fatigue evaluation methods, time function rule and ductility exhaustion method, was examined.

Ueta, Masahiro [Japan Atomic Power Co., Tokyo (Japan). Fast Breeder Reactor Development Dept.; Nishida, Takashi; Koto, Hiroyuki [Mitsubishi Heavy Industries, Ltd., Takasago (Japan). Takasago R and D Center; Sukekawa, Masayuki [Hitachi Ltd. (Japan); Taguchi, Kosei [Toshiba Corp., Yokohama (Japan). Nuclear Engineering Lab.

1995-12-01

101

Influence of oxide inclusions of the mechanical properties of steel with a low carbon content  

Microsoft Academic Search

The influence of the area occupied by inclusions on the mechanical properties of steel with deoxidation of molten commercially pure iron with aluminum, silicon, manganese, and mixtures of them was determined. A chemical analysis of the inclusions was made. The investigation data was processed mathematically. The influence of heat treatment on the composition of the inclusions was shown. 2 refs.,

I. B. Gutovskii; V. I. Bodnarchuk; V. G. Kochkin; V. A. Kolchanov

1992-01-01

102

Research of selected properties of two types of high manganese steel wires  

NASA Astrophysics Data System (ADS)

The article presents results of tests that aimed at establishing the impact of deformation on properties of wires made of two types of high manganese steels. The deformation process was carried out with the use of a draw bench machine at a speed of 0.5 m min-1. Mechanical properties and structure of strengthened and annealed wires for both steels at different levels of relative reduction in cross-section were determined. Strength of the tested materials was determined in the tensile test, while its hardness was measured with the Vickers hardness test method. Fractographic tests were performed using a scanning electron microscope. It was shown that at the beginning of tensile test, the investigated high manganese steels were characterized by very high plasticity and become stronger as the degree of deformation grows. Surfaces of fractures that were created in the areas where the sample was torn were analyzed. These fractures indicate the presence of transcrystalline ductile fractures.

Tomaszewska, A.; Jab?o?ska, M.; Hadasik, E.; Niewielski, G.; Kawalla, R.

2011-05-01

103

Leaching characteristics of steel slag components and their application in cementitious property prediction.  

PubMed

High-efficiency recovery and utilization of steel slag are important concerns for environmental protection and sustainable development. To establish a rapid method to evaluate the cementitious properties of steel slag, leaching tests were carried out on steel slag components via an evaporation-condensation method; the leaching characteristics and mechanism of the slag were also investigated. The relationship between leaching characteristics and cementitious properties, which were represented by mortar compressive strength, was analyzed. Results show that there exist significant differences among the amounts of chemically active leached components. The leaching process can be described by the shrinking unreacted core model controlled by intra-particle diffusion, and is in accordance with Kondo R hydration kinetics equation. The leaching process showed a good linear relationship between the amounts of components leached from steel slag and the mortar compressive strength of cementitious materials prepared from reference cement and steel slag with mass ratios of 50:50 and 70:30. The compressive strengths of mortars subjected to 7, 28, and 90 days of curing can be accurately predicted by the sum of leached (CaO+Al(2)O(3)) obtained after a certain length of leaching time. PMID:22088502

Li, Zaibo; Zhao, Sanyin; Zhao, Xuguang; He, Tusheng

2012-01-15

104

Physical and mechanical properties of cast 17-4 PH stainless steel  

Microsoft Academic Search

The physical and mechanical properties of an overaged 17-4 PH stainless steel casting have been examined. The tensile and compressive properties of cast 17-4 PH are only influenced to a slight degree by changing test temperature and strain rate. However, both the Charpy impact energy and dynamic fracture toughness exhibit a tough-to-brittle transition with decreasing temperature - this transition being

Rack

1981-01-01

105

Mechanical and physical properties of irradiated type 348 stainless steel  

SciTech Connect

A type 348 stainless steel in-pile tube irradiated to a fluence of 3 x 10/sup 22/ n/cm/sup 2/, E > 1 MeV (57 dpa), was destructively examined. The service had resulted in a maximum total creep of 1.8% at the high fluence. The metal temperature ranged between 623 and 652/sup 0/K, hence the thermal creep portion of the total was negligible. Total creep was greater than had been anticipated from creep data for austenitic stainless steels irradiated in other reactors. The objectives of the destructive examination were to determine the service-induced changes of mechanical and physical properties, and to assess the possibility of adverse effects of both these changes and the greater total creep on the prospective service life of other tubes.

Beeston, J.M.

1980-01-01

106

Ultrasonic Elastic Properties of Steel under Tensile Stress  

Microsoft Academic Search

Longitudinal and transverse wave velocities, eight kinds of elastic parameters and dilational and shear dampings of chromium-molybdenum steel have been simultaneously measured at room temperature in terms of acoustoelasticity, by an ultrasonic pulse method. Young, shear and bulk moduli and Lam parameter apparently decrease with increasing tensile stress, suggesting decrement of rigidity. However, decease in Poisson's ratio shows actual enhancement

Mikio Fukuhara; Asao Sampei

2000-01-01

107

Fracture properties evaluation of stainless steel piping for LBB applications  

SciTech Connect

The objective of this paper is to evaluate the material properties of SA312 TP316 and SA312 TP304 stainless steels and their associated welds manufactured for shutdown cooling line and safety injection line of nuclear generating stations. A total of 82 tensile tests and 58 fracture toughness tests on specimens taken from actual pipes were performed and the effect of various parameters such as the pipe size, the specimen orientation, the test temperature and the welding procedure on the material properties are discussed. Test results show that the effect of the test temperature on the fracture toughness was significant while the effects of the pipe size and the specimen orientation on the fracture toughness were negligible. The material properties of the GTAW weld metal was in general higher than those of the base metal.

Kim, Y.J.; Seok, C.S.; Chang, Y.S. [Sung Kyun Kwan Univ., Suwon (Korea, Republic of)

1997-04-01

108

Properties of submerged arc welded TMCP-steel weldments  

SciTech Connect

In this investigation weldability, mechanical properties and effects of different heat inputs and welding consumables on the properties of weldments of the thermomechanically control processed (TMCP) steel, RAEX 500M were examined. The hardness measurements and transverse tensile tests showed that HAZ softening was insignificant in the TMCP-steel weldments studied. The weld metal strength properties were equal to or higher than those of the base metal through the heat input range of 2.0 to 6.0 kJ/mm. The required low temperature impact toughness of 40 J was achieved with plate thickness of 40 mm at {minus}60 C with all the filler materials used except with S2Ni2 (welding energy 5.8 kJ/mm) and S2Ni2 with metal powder addition (welding energy 5.9 kJ/mm). With high welding energies and longer cooling times (t{sub 8/5}) favorable weld metal microstructures were achieved with Mo-, Ti- and B-alloyed filler materials.

Kotamies, J.M.N.; Brederholm, A.T.; Haenninen, H.E. [Helsinki Univ. of Technology, Espoo (Finland). Lab. of Engineering Materials

1996-12-01

109

Creep properties of modified 9 Cr-1 Mo steel  

SciTech Connect

Creep properties of modified 9 Cr-1 Mo steel, an alloy significantly improved in elevated-temperature strength over 2 1/4 Cr-1 Mo and other similar alloys, are presented here. Data are primarily on material in the normalized and tempered condition. Effects of variables such as isothermal annealing treatment, cold work, normalizing temperature, tempering temperature, notch, and biaxial stress state have also been examined. Data analysis and comparisons have shown that modified 9 Cr-1 Mo alloy is very insensitive in response to several material variables, heat treatments, and specimen design variables.

Sikka, V.K.; Cowgill, M.G.; Roberts, B.W.

1983-01-01

110

Microstructures and Mechanical Properties of High-Mn TRIP Steel Based on Warm Deformation of Martensite  

NASA Astrophysics Data System (ADS)

High-Mn TRIP steel with about 5 wt pct Mn was prepared by a thermo-mechanical treatment based on warm deformation of martensite and subsequent short-time annealing in the intercritical region. The microstructural evolution and the mechanical properties of the used steel during such treatment were investigated. The results indicate that during warm deformation of martensite in the intercritical region, the decomposition of martensite was accelerated by warm deformation and the occurrence of dynamic recrystallization of ferrite led to the formation of equiaxed ferrite grains. Meanwhile, the reverse transformation of austenite was accelerated by warm deformation to some extent. During subsequent annealing in the intercritical region, static recrystallization of ferrite led to the increase in the fraction of equiaxed ferrite grains, and the formation of the reversed austenite was accelerated by the addition of the deformation-stored energy, while the stability of the reversed austenite was improved by the accelerated diffusions of C atoms and Mn atoms. As a whole, the mechanical properties of the used steel by the thermo-mechanical treatment based on warm deformation of martensite and subsequent short-time annealing in the intercritical region were comparable to the steels with similar compositions subjected to intercritical annealing for hours after cold rolling of martensite.

Guo, Zhikai; Li, Longfei; Yang, Wangyue; Sun, Zuqing

2015-01-01

111

Effects of Inclusions on Delayed Fracture Properties of Three TWinning Induced Plasticity (TWIP) Steels  

NASA Astrophysics Data System (ADS)

In the present study, delayed fracture properties of a high-Mn TWinning Induced Plasticity (TWIP) steel and two Al-added TWIP steels were examined by dipping tests of cup specimens in the boiled water, after which the microcrack formation behavior was analyzed. The TWIP steels contained a small amount of elongated MnS inclusions, spherical-shaped AlN particles, and submicron-sized (Fe,Mn)3C carbides. Since MnS inclusions worked as crack initiation sites, longitudinal cracks were formed along the cup forming direction mostly by MnS inclusions. These cracks were readily grown when high tensile residual stresses affected the cracking or hydrogen atoms were gathered inside cracks, which resulted in the delayed fracture. In the Al-added steels, MnS inclusions acted as crack initiation and propagation sites during cup forming or boiled-water dipping test, but residual stresses applied to MnS might be low for the crack initiation and growth. Thus, longitudinal cracks formed by MnS inclusions did not work much for delayed fracture. AlN particles present in the Al-added steels hardly acted as crack initiation or growth sites for the delayed fracture because of their spherical shape.

Hong, Seokmin; Shin, Sang Yong; Kim, Hyoung Seop; Lee, Sunghak; Kim, Sung-Kyu; Chin, Kwang-Geun; Kim, Nack J.

2013-02-01

112

Properties of steel 30KhGSA melted from different charges  

Microsoft Academic Search

1.The use of a primal charge in the production of steel 30KhGSA helps increase its ductility, reduce the threshold of cold shortness after refinement, and it has practically no effect on the strength properties. The bulk hardenability of steel melted from FSB and SI is poorer than of steel melted from SMP.2.Steels melted from SI and FSB contain fewer microimpurities

N. N. Sergeev; E. V. Tin'kova; A. V. Tereshchenko

1988-01-01

113

Effect of microstructure on static and dynamic mechanical properties of high strength steels  

NASA Astrophysics Data System (ADS)

The high speed deformation behavior of a commercially available dual phase (DP) steel was studied by means of split Hopkinson bar apparatus in shear punch (25m/s) and tension (1000s-1) modes with an emphasis on the influence of microstructure. The cold rolled sheet material was subjected to a variety of heat treatment conditions to produce several different microstructures, namely ferrite plus pearlite, ferrite plus bainite and/or acicular ferrite, ferrite plus bainite and martensite, and ferrite plus different fractions of martensite. Static properties (0.01mm/s for shear punch and 0.001s -1 for tension) of all the microstructures were also measured by an MTS hydraulic machine and compared to the dynamic properties. The effects of low temperature tempering and bake hardening were investigated for some ferrite plus martensite microstructures. In addition, two other materials, composition designed as high strength low alloy (HSLA) steel and transformation induced plasticity (TRIP) steel, were heat treated and tested to study the effect of alloy chemistry on the microstructure and property relationship. A strong effect of microstructure on both static and dynamic properties and on the relationship between static and dynamic properties was observed. According to the variation of dynamic factor with static strength, three groups of microstructures with three distinct behaviors were identified, i.e. classic dual phase (ferrite plus less than 50% martensite), martensite-matrix dual phase (ferrite plus more than 50% martensite), and non-dual phase (ferrite plus non-martensite). Under the same static strength level, the dual phase microstructure was found to absorb more dynamic energy than other microstructures. It was also observed that the general dependence of microstructure on static and dynamic property relationship was not strongly influenced by chemical composition, except the ferrite plus martensite microstructures generated by the TRIP chemistry, which exhibited much better dynamic factor values. This may suggest that solid solution strengthening should be more utilized in the design of crashworthy dual phase steels.

Qu, Jinbo

114

Influence of Processing and Heat Treatment on Corrosion Resistance and Properties of High Alloyed Steel Coatings  

NASA Astrophysics Data System (ADS)

Corrosion and abrasive wear are two important aspects to be considered in numerous engineering applications. Looking at steels, high-chromium high-carbon tool steels are proper and cost-efficient materials. They can either be put into service as bulk materials or used as comparatively thin coatings to protect lower alloyed construction or heat treatable steels from wear and corrosion. In this study, two different corrosion resistant tool steels were used for the production of coatings and bulk material. They were processed by thermal spraying and super solidus liquid phase sintering as both processes can generally be applied to produce coatings on low alloyed substrates. Thermally sprayed (high velocity oxygen fuel) coatings were investigated in the as-processed state, which is the most commonly used condition for technical applications, and after a quenching and tempering treatment. In comparison, sintered steels were analyzed in the quenched and tempered condition only. Significant influence of alloy chemistry, processing route, and heat treatment on tribological properties was found. Experimental investigations were supported by computational thermodynamics aiming at an improvement of tribological and corrosive resistance.

Hill, Horst; Weber, Sebastian; Raab, Ulrich; Theisen, Werner; Wagner, Lothar

2012-09-01

115

Effect of rust on the wettability of steel by water  

SciTech Connect

Rust, as formed on steel by immersion of low-carbon steel in water, was found to improve the wettability of steel by water. The advancing contact angle decreased from 87{degree} to 32{degree}, and the receding contact angle decreased from 81{degree} to 29{degree}. Cleansing of steel by acetone also helped improve the wettability, but the advancing angle only decreased from 87{degree} to 73{degree}, and the receding angle only decreased from 81{degree} to 41{degree}.

Lu, W.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.] [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

1998-04-01

116

Characterization of thermal aging of duplex stainless steel by SQUID  

SciTech Connect

Thermal aging is a growing concern for long-term-aged duplex stainless steel piping in nuclear power plants. Superconducting QUantum Interference Device (SQUID) was used for the detection of thermal aging of SUS329 rolled duplex stainless steel and SCS16 cast duplex stainless steel. It was found that the SQUID output signal pattern in the presence of AC magnetic field applied to the specimen was sensitive to the changes in electromagnetic properties due to thermal aging.

Isobe, Y.; Kamimura, A.; Aoki, K.; Nakayasu, F. [Nuclear Fuel Industries, Ltd., Osaka (Japan)

1995-08-01

117

Structure and properties of a steel strip cut from the Garin-Mikhailovskii railroad bridge in Novosibirsk  

NASA Astrophysics Data System (ADS)

The results of a study of the structure and mechanical properties of a steel strip cut from the first railroad bridge across the Ob river constructed 120 years ago are given. The steel for the bridge was made at the Votkinsk plant in the Urals at the end of the 19th century. In this work, the chemical composition of the steel has been analyzed and a comparison of the quality of the material with the contemporary analogs has been carried out. It has been established that the steel used in the production of the bridge is characterized by a low content of sulfur and phosphorus. At the same time, the metal contains an enhanced content of nonmetallic inclusions. The presence of inclusions oriented in the rolling direction favorably affects the resistance to fatigue cracking of the steel. The cracks are retarded at the boundaries between the inclusions and the metallic matrix.

Nikulina, A. A.; Smirnov, A. I.; Popelyukh, A. I.; Bataev, A. A.; Popelyukh, P. A.

2015-01-01

118

The microstructure and properties of a quenched and tempered low-carbon-manganese-niobium steel  

Microsoft Academic Search

The effects of rolling parameters (deformation schedule and finishing temperature), cooling rate (direct quench and air cool),\\u000a and heat treatment have been investigated for a low carbon-manganese-niobium steel. Microstructure was characterized by optical\\u000a and transmission electron microscopy, and correlated with tensile and impact properties. The best combination of strength\\u000a and toughness was obtained by controlled rolling low in the austenite

1976-01-01

119

Report on thermal aging effects on tensile properties of ferritic-martensitic steels.  

SciTech Connect

This report provides an update on the evaluation of thermal-aging induced degradation of tensile properties of advanced ferritic-martensitic steels. The report is the first deliverable (level 3) in FY11 (M3A11AN04030103), under the Work Package A-11AN040301, 'Advanced Alloy Testing' performed by Argonne National Laboratory, as part of Advanced Structural Materials Program for the Advanced Reactor Concepts. This work package supports the advanced structural materials development by providing tensile data on aged alloys and a mechanistic model, validated by experiments, with a predictive capability on long-term performance. The scope of work is to evaluate the effect of thermal aging on the tensile properties of advanced alloys such as ferritic-martensitic steels, mod.9Cr-1Mo, NF616, and advanced austenitic stainless steel, HT-UPS. The aging experiments have been conducted over a temperature of 550-750 C for various time periods to simulate the microstructural changes in the alloys as a function of time at temperature. In addition, a mechanistic model based on thermodynamics and kinetics has been used to address the changes in microstructure of the alloys as a function of time and temperature, which is developed in the companion work package at ANL. The focus of this project is advanced alloy testing and understanding the effects of long-term thermal aging on the tensile properties. Advanced materials examined in this project include ferritic-martensitic steels mod.9Cr-1Mo and NF616, and austenitic steel, HT-UPS. The report summarizes the tensile testing results of thermally-aged mod.9Cr-1Mo, NF616 H1 and NF616 H2 ferritic-martensitic steels. NF616 H1 and NF616 H2 experienced different thermal-mechanical treatments before thermal aging experiments. NF616 H1 was normalized and tempered, and NF616 H2 was normalized and tempered and cold-rolled. By examining these two heats, we evaluated the effects of thermal-mechanical treatments on material microstructures and associated mechanical properties during long-term aging at elevated temperatures. Thermal aging experiments at different temperatures and periods of time have been completed: 550 C for up to 5000 h, 600 C for up to 7500 h, and 650 C for more than 10,000 h. Tensile properties were measured on thermally aged specimens and aging effect on tensile behavior was assessed. Effects of thermal aging on deformation and failure mechanisms were investigated by using in-situ straining technique with simultaneous synchrotron XRD measurements.

Li, M.; Soppet, W.K.; Rink, D.L.; Listwan, J.T.; Natesan, K. (Nuclear Engineering Division)

2012-05-10

120

Microstructure and mechanical properties of Selective Laser Melted 18Ni-300 steel  

NASA Astrophysics Data System (ADS)

Selective Laser Melting (SLM) is an Additive Manufacturing process in which a part is built in a layer by layer manner. A laser source selectively scans the powder bed according to the CAD data of the part to be produced. The high intensity laser beam makes it possible to completely melt the metal powder particles to obtain almost fully dense parts. In this work, the influence of process parameters in SLM (e.g. scan speed and layer thickness) and various age hardening treatments on the microstructure and mechanical properties of 18Ni-300 steel is investigated. It is shown that almost fully dense parts with mechanical properties comparable to those of conventionally produced maraging steel 300 can be produced by SLM.

Kempen, K.; Yasa, E.; Thijs, L.; Kruth, J.-P.; Van Humbeeck, J.

121

Molybdate adsorption from steel slag eluates by subsoils.  

PubMed

Steel slags are industrial by-products which are generated in large amounts worldwide, e.g. 150-23010(6) Mg in 2012, and which are partly used for construction. Molybdenum (Mo) can be added during steel processing in order to harden the steel. The objective of this study was to evaluate the adsorption behaviour of molybdate (MoO4(2-)) from slag eluates in subsoils. Molybdate batch adsorption experiments were carried out with eluates obtained from two different kinds of steel slags (i) LD slag (Linz-Donawitz operation, LDS) and (ii) electric arc furnace slag (EAF) to assess the risk that may arise from the contamination of groundwater by the leaching of molybdate. Six different subsoils were chosen in order to provide a wide range of chemical properties (pH 4.0-7.6; dithionite-extractable Fe 0.73-14.7 g kg(-1)). Molybdate adsorption experiments were carried out at the pH of the steel slag eluates (pH 11-12) as well as at pH values adjusted to the soil pH. The data were evaluated with the Freundlich equation. Molybdate adsorption exhibited a maximum near pH 4 for steel slag eluates adjusted to the soil pH, and decreased rapidly with increasing pH until adsorption was virtually zero at pH>11. Adsorption was greater for soils with high amounts of dithionite-extractable Fe oxides. The extent and behaviour of molybdate adsorption from both eluates was similar. After a reaction time of 24h, the pH of the EAF slag eluate was lower than that of the LD steel slag eluate, which was caused by different acid buffer capacities. Some soils were able to decrease the pH of the EAF slag eluates by about 4 pH units, enhancing the adsorption of molybdate. Transport simulations indicated that molybdate discharge is low in acidic soils. PMID:23973286

Matern, K; Rennert, T; Mansfeldt, T

2013-11-01

122

Simulation of the Mechanical Performance of Cast Steel with Porosity: Static Properties  

E-print Network

Simulation of the Mechanical Performance of Cast Steel with Porosity: Static Properties R.A. Hardin, characteristics and effects of porosity on properties is more critical than ever. In the work presented here, a method for incorporating the effect of porosity on steel stiffness (elastic modulus) is presented

Beckermann, Christoph

123

Processing, Microstructures and Properties of a Dual Phase Precipitation-Hardening PM Stainless Steel  

Microsoft Academic Search

To improve the mechanical properties of PM stainless steels in comparison with their wrought counterparts, a PM stainless steel alloy was developed which combines a dual-phase microstructure with precipitation-hardening. The use of a mixed microstructure of martensite and ferrite results in an alloy with a combination of the optimum properties of each phase, namely strength and ductility. The use of

Christopher Schade

2010-01-01

124

Effect of d-ferrite on impact properties of supermartensitic stainless steel  

E-print Network

Effect of d-ferrite on impact properties of supermartensitic stainless steel heat affected zones D of the presence of non-equilibrium d-ferrite on the impact properties of a supermartensitic stainless steel. To generate homogeneous d-ferrite containing microstruc- tures the material was, in the first part

Cambridge, University of

125

Effect of phosphorus segregation on fracture properties of 2.25Cr1Mo pressure vessel steel  

Microsoft Academic Search

Phosphorus is a very common trace element that can segregate at prior austenite grain boundaries and\\/or carbide\\/matrix interfaces\\u000a of low alloy steels at high temperature (e.g., order of 500 ?C) and adversely affect the fracture properties. This paper investigates\\u000a segregation of P during reversible temper embrittlement (96 h at 520 ?C) of quenched and fully tempered 2.25Cr-1Mo steel by\\u000a Auger

M. A. Islam; M. Novovic; P. Bowen; J. F. Knott

2003-01-01

126

Microstructure and mechanical properties of VTiN microalloyed steel used for fracture splitting connecting rod  

Microsoft Academic Search

A new kind of VTiN high strength microalloyed medium carbon steel has been developed, which is used for fracture splitting\\u000a connecting rod. In this article, the characteristics of this carbon steel and its production process were studied. The microstructure,\\u000a precipitated phases and their effects on mechanical properties were investigated by optical microscope, SEM, and TEM. The\\u000a results showed that the

Xianzhong Zhang; Qizhou Cai; Guifeng Zhou; Qingfeng Chen; Yuzhang Xiong

2011-01-01

127

Microstructure and mechanical properties of weld fusion zones in modified 9Cr-1Mo steel  

NASA Astrophysics Data System (ADS)

Modified 9Cr-1Mo steel finds increasing application in power plant construction because of its excellent high-temperature properties. While it has been shown to be weldable and resistant to all types of cracking in the weld metal and heat-affected zone (HAZ), the achievement of optimum weld metal properties has often caused concern. The design of appropriate welding consumables is important in this regard. In the present work, plates of modified 9Cr-1Mo steel were welded with three different filler materials: standard 9Cr-1Mo steel, modified 9Cr-1Mo, and nickel-base alloy Inconel 182. Post-weld heat treatment (PWHT) was carried out at 730 and 760 C for periods of 2 and 6 h. The joints were characterized in detail by metallography. Hardness, tensile properties, and Charpy toughness were evaluated. Among the three filler materials used, although Inconel 182 resulted in high weld metal toughness, the strength properties were too low. Between modified and standard 9Cr-1Mo, the former led to superior hardness and strength in all conditions. However, with modified 9Cr-1Mo, fusion zone toughness was low and an acceptable value could be obtained only after PWHT for 6 h at 760 C. The relatively poor toughness was correlated to the occurrence of local regions of untransformed ferrite in the microstructure.

Sireesha, M.; Sundaresan, S.; Albert, Shaju K.

2001-06-01

128

Structure and mechanical and corrosion properties of new high-nitrogen Cr-Mn steels containing molybdenum  

NASA Astrophysics Data System (ADS)

The structure, mechanical properties, and pitting corrosion of nickel-free high-nitrogen (0.8% N) austenitic 06Kh18AG19M2 and 07Kh16AG13M3 steels have been studied in various structural states obtained after hot deformation, quenching, and tempering at 300 and 500C. Both steels are shown to be resistant to the ? ? ? and ? ? ? martensite transformations irrespective of the decomposition of a ? solid solution (06Kh18AG19M2 steel). Austenite of the steel with 19 wt % Mn shows lower resistance to recrystallization, which provides its higher plasticity (?5) and fracture toughness at a lower strength as compared to the steel with 13 wt % Mn. Electrochemical studies of the steels tempered at 300 and 500C show that they are in a stable passive state during tests in a 3.5% NaCl solution and have high pitting resistance up to a potential E pf = 1.3-1.4 V, which is higher than that in 12Kh18N10T steel. In the quenched state, the passive state is instable but pitting formation potentials E pf retain their values. In all steels under study, pitting is shown to form predominantly along the grain boundaries of nonrecrystallized austenite. The lowest pitting resistance is demonstrated by the structure with a double grain boundary network that results from incomplete recrystallization at 1100C and from the existence of initial and recrystallized austenite in the 07Kh16AG13M3 steel. To obtain a set of high mechanical and corrosion properties under given rolling conditions (1200-1150C), annealing of the steels at temperatures no less than 1150C (for 1 h) with water quenching and tempering at 500C for 2 h are recommended.

Berezovskaya, V. V.; Savrai, R. A.; Merkushkin, E. A.; Makarov, A. V.

2012-05-01

129

Influence of gas nitriding pressure on the surface properties of ASTM F138 stainless steel  

Microsoft Academic Search

The present work investigates the influence of gas nitriding pressure on the modification of surface properties of ASTM F138 stainless steel. Nitrided surfaces were characterized by X-ray diffraction, Conversion Electron Mssbauer Spectroscopy, Scanning Electron Microscopy and Vickers microhardness. Plasma nitriding was carried out in a medium of 80% H2 and 20% N2, at 400C, for 4h, pressures between 3 and

S. D. de Souza; M. Kapp; M. Olzon-Dionysio; M. Campos

2010-01-01

130

Effect of component and microstructure on impact wear property and mechanism of steels in corrosive condition  

Microsoft Academic Search

The impact corrosion and abrasion behavior of three kinds of steel used in the liner of wet-grinding machine in metallurgical industry is investigated under impact energy of 2.7J in acidironstone slurry, the test was carried out by a modified MLD-10 tester. It was shown that under the same simulated conditions, the impact corrosion and abrasion property of the low carbon

Hou-fu Ding; Fang-ming Cui; Xiao-dong Du

2006-01-01

131

Low-Density Steels: The Effect of Al Addition on Microstructure and Properties  

NASA Astrophysics Data System (ADS)

Density reduction of automotive steels is needed to reduce fuel consumption, thereby reducing greenhouse gas emissions. Aluminum addition has been found to be effective in making steels lighter. Such an addition does not change the crystal structure of the material. Steels modified with aluminum possess higher strength with very little compromise in ductility. In this work, different compositions of Fe-Al systems have been studied so that the desired properties of the material remain within the limit. A density reduction of approximately 10% has been achieved. The specific strength of optimal Fe-Al alloys is higher than conventional steels such as ultra-low-carbon steels.

Pramanik, Sudipta; Suwas, Satyam

2014-09-01

132

Ductile fracture properties of selected line-pipe steels  

SciTech Connect

This report is the first of a series of topical reports presenting the results of research to assess the effects of a hydrotest and repeated hydrotesting on flaw growth in line pipes. This report presents ductile fracture properties that are used in assessing stable flow growth in line pipes. These properties are presented following a brief discussion of the J-tearing theory that forms the basis for the analysis method that has been developed. The specific properties presented are the J-initiation resistance to cracking (J{sub Ic}) and the J-tearing resistance to stable crack extension (T{sub R}). Test methods to develop these properties are presented along with discussion of data analysis. Results are presented for three line-pipe steels for the LT (through-wall axial flaw) orientation, for three levels of prestrain. The results show a strong dependence of J{sub Ic} on prestrain with initiation resistance decreasing as prestrain increases. Initiation resistance also was shown to increase with increasing flow stress, s{sub f}. In contrast, tearing resistance was not uniquely dependent on flow stress and was independent of prior prestrain. 36 refs., 10 figs., 1 tab.

Leis, B.N.; Brust, F.W.

1990-01-01

133

Effects of neutron irradiation on tensile properties of oxide dispersion strengthened (ODS) steel claddings  

NASA Astrophysics Data System (ADS)

The effects of fast neutron irradiation on ring tensile properties of oxide dispersion strengthened (ODS) steel claddings for fast reactor were investigated. Specimens were irradiated in the experimental fast reactor Joyo using the material irradiation rig at temperatures between 693 and 1108 K to fast neutron doses ranging from 16 to 33 dpa. The post-irradiation ring tensile tests were carried out at irradiation temperatures. The experimental results showed that there was no significant change in tensile strengths after neutron irradiation below 923 K, but the tensile strengths at neutron irradiation above 1023 K up to 33 dpa were decreased by about 20%. On the other hand, uniform elongation after irradiation was more than 2% at all irradiation conditions. The ring tensile properties of these ODS claddings remained excellent within these irradiation conditions compared with conventional 11Cr ferritic/martensitic steel (PNC-FMS) claddings.

Yano, Y.; Ogawa, R.; Yamashita, S.; Ohtsuka, S.; Kaito, T.; Akasaka, N.; Inoue, M.; Yoshitake, T.; Tanaka, K.

2011-12-01

134

Elevated temperature mechanical properties of a reactor pressure vessel steel  

NASA Astrophysics Data System (ADS)

A testing program is in progress to define the tensile and creep properties of SA533 Grade B Class 1 steel at temperatures from 371 to 538 C. The overall objective is to provide the data necessary to obtain ASME Code approval for use of this material for the Modular High-Temperature Gas-Cooled Reactor (MHTGR) vessel during short-term temperature excursions above 371 C. Testing and evaluation involve three heats of base metal, two submerged arc welds, and a shielded metal arc weld. The creep strengths of the base metal heats and the weldments were found to be equivalent; the weld metal itself is slightly stronger. The data obtained indicate that stress to produce 1% strain will likely be the controlling factor in setting the allowable stresses for design.

McCoy, H. E.; Rittenhouse, P. L.

1990-04-01

135

Mechanical properties and microstructure evolution of CLAM Steel in tube fabrication and test blanket module assembly  

NASA Astrophysics Data System (ADS)

The first wall of the China dual functional lithium lead-test blanket module (DFLL-TBM) will be assembled with China low activation martensitic (CLAM) steel rectangular tubes and plates by hot isostatic pressing (HIP) - diffusion welding. The objective of this study is to evaluate CLAM rectangular tubes and investigate mechanical property and microstructure evolution of CLAM steel in tube fabrication and TBM assembly. In this work, CLAM rectangular tubes with lengths of 1500 mm were fabricated, and the dimensional accuracy met the requirement for HIP joining. In the tube fabrication process, the CLAM steel was annealed to improve its ductility. In addition, the anisotropy in mechanical properties and microstructure introduced by tube rolling was eliminated according to the simulation of HIP heat treatment in TBM preparation. The tensile strength of the CLAM tubes with final heat treatment was slightly higher than that of CLAM steel with the published standard heat treatment, while the total elongation was reduced. This revealed that a post-HIP heat treatment was required before the final heat treatment. An annealing treatment at 1253 K transformed martensite to ferrite, decreased the tensile strength, and increase the ductility; Rolling deformation introduced microstructural anisotropy, increased the Vickers hardness, and created an inhomogeneous hardness distribution; A simulated HIP heat treatment schedule removed these differences in hardness and tensile strength due to the anisotropy; The tensile strength of CLAM tube material given the published standard heat treatment (with the simulated HIP heat treatment) was higher than that of previously published CLAM steel results and the elongation was reduced. Therefore, a post-HIP heat treatment for CLAM tube material appears to be required before applying a final heat treatment based on the prior standard heat treatment in order to preserve the overall tensile elongation.

Huang, Bo; Huang, Qunying; Li, Yanfen; Li, Chunjing; Wu, Qingsheng; FDS Team

2013-11-01

136

Creep, fatigue, and creep-fatigue properties of modified 9Cr-1Mo steel weldments  

SciTech Connect

In this paper, the results of creep-rupture, fatigue, and creep-fatigue tests obtained for the weldments of modified 9Cr-1Mo steel at elevated temperatures (500, 550 and 600 C) are presented. The fatigue properties of weldment, such as fatigue life, stress-strain response, and failure location, can be predicted well by the bi-element model of base metal and weld metal which have their corresponding mechanical properties. Furthermore, the creep-fatigue life of weldment can be predicted well by the bi-linear model.

Taguchi, Kosei; Maruyama, Shigeki [Toshiba Corp., Yokohama (Japan); Fujioka, Terutaka [Japan Atomic Power Co., Tokyo (Japan); Yamashita, Yoshihiro [Hitachi, Ltd. (Japan); Koto, Hiroyuki [Mitsubishi Heavy Industries, Ltd., Takasago (Japan); Takahashi, Koun [Ishikawajima-Harima Heavy Industries Co., Ltd., Tokyo (Japan); Toya, Yuji [Kawasaki Heavy Industries, Ltd., Noda (Japan); Sato, Takashi [Babcock-Hitachi K.K., Kure (Japan)

1996-12-01

137

Adsorption properties and inhibition of mild steel corrosion in 15% HCl by 3-((1H-indol-3-yl)(4-methoxyphenyl)methyl)-1H-indole:electrochemical study  

NASA Astrophysics Data System (ADS)

The inhibiting effect of 3-((1H-indol-3-yl)(4-methoxyphenyl)methyl)-1H-indole (IMMI) on the corrosion of mild steel (MS) in 15% HCl solution has been studied by using potentiodynamic polarization technique. The polarization data revealed that IMMI acts as a mixed type inhibitor for mild steel in acid solution.. The adsorption of the inhibitors on the mild steel surface was found to obey Langmuir's adsorption isotherm. Inhibition efficiency was found to be greater than 95% and inhibition is governed by both physical adsorption and chemisorption mechanism.

Behera, Debasis; Kumar, Sushil; Sinha, Rajesh Ranjan; Yadav, Mahendra

2014-04-01

138

High-temperature properties and microstructure of Mo microalloyed ultra-high-strength steel  

NASA Astrophysics Data System (ADS)

The high-temperature mechanical properties and microstructure of forging billets of C-Si-Mn-Cr and C-Si-Mn-Cr-Mo ultra-high-strength cold-rolled steels (tensile strength?1000 MPa, elongation?10%) were studied. Through the comparison of reduction in area and hot deformation resistance at 600-1300C, the Mo-containing steel was found to possess a higher strength and a better plasticity than the Mo-free one. The equilibrium phase diagram and atom fraction of Mo in different phases at different temperatures were calculated by Thermo-Calc software (TCW). The results analyzed by using transmission electron microscopy and TCW show that precipitates in the Mo-containing steel are primarily M23C6, which promote pearlite formation. The experimental data also show that a lower ductility point existing in the Mo-free steel at 850C is eliminated in the Mo-containing one. This is mainly due to the segregation of Mo at grain boundaries investigated by electron probe microanalysis (EPMA), which improves the strength of grain boundaries.

Han, Qi-Hang; Kang, Yong-Lin; Zhao, Xian-Meng; Gao, Lu-Feng; Qiu, Xue-Song

2011-08-01

139

Properties of Galvanized and Galvannealed Advanced High Strength Hot Rolled Steels  

SciTech Connect

The objectives of the project were (i) to develop the coating process information to achieve good quality coatings on 3 advanced high strength hot rolled steels while retaining target mechanical properties, (ii) to obtain precise knowledge of the behavior of these steels in the various forming operations and (iii) to establish accurate user property data in the coated conditions. Three steel substrates (HSLA, DP, TRIP) with compositions providing yield strengths in the range of 400-620 MPa were selected. Only HSLA steel was found to be suitable for galnaizing and galvannealing in the hot rolled condition.

V.Y. Guertsman; E. Essadiqi; S. Dionne; O. Dremmailova; R. Bouchard; B. Voyzelle; J. McDermid; R. Fourmentin

2008-04-01

140

Microstructures and wear properties of TiN-based cermet coating deposited on 1Cr18Ni9Ti stainless steel by electrospark process  

Microsoft Academic Search

A simple and effective surface treatment technique, electrospark deposition (ESD), has been successfully applied to deposit TiN-based cermet coating on stainless steel substrate. The nitrided coating had an average thickness of about 30?m and formed metallurgical bonding with the substrate. The microstructure of the coating was mainly composed of TiN phase and ferrite (?-FeCr) phase. Its microhardness reached 889HV. The

X. Li; D. Q. Sun; X. Y. Zheng; Z. A. Ren

2008-01-01

141

Study on the morphology and properties of carburized and austempered microstructures in 430 D2 steel  

SciTech Connect

By means of carburizing and quenching, a high hard case can be produced in the surface of tool steel, but the brittleness of the case has limited its application in practice. In this paper, structure, composition and properties of the case and core carburized followed by austempering in 430D2 steel was studied. As the result of austempering, the optimum combination of strength and ductility of the carburized case has been achieved. There was no M3C phase in carburized case, indicating that the composition point of the carburized case lies in the M7C3 + Austenite quarter-phase field. In the isothermal period above Ms, lower bainite formed in the core structure, while a needle-like structure without carbides emerged in the outside case after a longer isothermal time. This dark needle-like structure seemed to be the isothermal martensite, which appeared to be dark since it was tempered in the following isothermal process. This tempered isotherm martensite probably improved the toughness and ductility of the carburized case; on the other hand, a large quantity of fine carbide formed in carburizing increased the wear resistance of the die steel and remedied the defect of heterogeneity of carbides in 430 D2 steel.

Xinggui, W.; Suidong, Z.; Xin, C.; Chuenmei, L.; Liming, X. [Univ. of Science and Engineering, Tianjin (China)

1995-12-31

142

The effect of carbon concentration and plastic deformation on ultrasonic higher order elastic properties of steel  

NASA Technical Reports Server (NTRS)

The behavior of higher order elastic properties, which are much more sensitive to material state than are second order properties, has been studied for steel alloys AISI 1016, 1045, 1095, and 8620 by measuring the stress derivative of the acoustic natural velocity to determine the stress acoustic constants (SAC's). Results of these tests show a 20 percent linear variation of SAC's with carbon content as well as even larger variations with prestrain (plastic deformation). The use of higher order elastic characterization permits quantitative evaluation of solids and may prove useful in studies of fatigue and fracture.

Heyman, J. S.; Allison, S. G.; Salama, K.

1985-01-01

143

Thermophysical Properties of a Hot-Work Tool-Steel with High Thermal Conductivity  

NASA Astrophysics Data System (ADS)

In the highly productive permanent mold-casting process, the released enthalpy of the solidifying metal has to be transported through the surrounding hot-work tool-steel to the cooling system. For that reason, the thermal conductivity is a key property of the employed tool-steel. Recently, a new type of steel (Rovalma HTCS 130) has been developed and superior thermal properties have been claimed. In this study, measurements of the thermal diffusivity, heat capacity, and thermal expansion as a function of temperature are described for this steel and results of the computed thermal conductivity are reported. There is quite a discrepancy between the specification of the steel supplier and the results of this study; however, an improvement of the thermal conductivity for this type of steel can be confirmed.

Kaschnitz, E.; Hofer, P.; Funk, W.

2013-05-01

144

Mechanical properties and corrosion resistance of low-alloy steels in atmospheric conditions containing chloride  

Microsoft Academic Search

The corrosion resistance (weight loss) and mechanical properties (i.e., yield strength, ultimate tensile strength, and elongation) of four newly developed low-alloy steels (LAS) were compared with a weathering steel (Acr-Ten A) and a carbon steel (SS400) using a laboratory-accelerated test that involved cyclic wet\\/dry conditions in a chloride environment (5wt.% NaCl). The new LAS were designated 1604A, 1604B, 1605A, and

Y. Y. Chen; H. J. Tzeng; L. I. Wei; H. C. Shih

2005-01-01

145

Structure and properties of low-carbon high-manganese cast steels for cryogenic use  

Microsoft Academic Search

A low carbon content and a relatively high manganese\\/carbon ratio have a marked effect in promoting the toughness of Mn-C cast steels at low temperatures. In the case of a low carbon content, cast steel with an austenitic matrix containing epsilon-martensite has good mechanical properties at low temperatures. The advantage of the cast steel with a ..gamma.. + epsilon structure

L. S. Li; C. M. Wayman; G. S. Wei; D. Z. Yang

1982-01-01

146

Reliability of dual compounds carbide composite+steel produced by diffusion welding  

Microsoft Academic Search

This paper focuses on the reliability (strength and residual welding stresses) of the dual compound of TiC-based composite+steel and WC-based hardmetal+steel produced by diffusion bonding (welding). Vacuum brazing was used as a reference technology. The influence of some metallurgical factors on the properties and structure of joints was investigated by SEM and EPMA. It was found that the TiC-based cermet

H. Klaasen; J. Kbarsepp; A. Laansoo; M. Viljus

2010-01-01

147

Microstructures and properties of high Cr content coatings on inner surfaces of carbon steel tubular components prepared by a novel mechanical alloying method  

NASA Astrophysics Data System (ADS)

In the present work, a novel mechanical alloying method was developed to prepare high Cr content coatings on the inner surface of carbon steel tubular components using a planetary ball mill. The microstructure and elemental and phase composition of mechanically alloyed coatings at different processing conditions were studied using SEM, XRD, and EDX. It showed that a proper increase in the applied milling time and the disc rotation speed favored the improvement in the thickness, surface smoothness, densification level, and microstructural homogeneity of the deposited coatings. With processing conditions optimized (rotation speed of 500 rpm and milling time of 10 h), a fully dense, 120 ?m thick, high Cr content coating, consisting of metal Cr and Fe-20Cr solid solution alloy, was metallurgically bonded to the inner substrate. Comparative studies on the microhardness, corrosion resistance, and anti-oxidation capability of carbon steel substrates with and without coatings were performed. It was found that the maximum microhardness of the coating reached HV 0.1667, showing a threefold improvement upon the substrate. The coated surfaces exhibited favorable resistance against corrosion and thermal oxidation as compared with the bare substrate. Based on two important action mechanisms (i.e., friction effect and impact effect) associated with a planetary ball mill, a reasonable mechanism was presented for the formation of mechanically alloyed coatings on inner surfaces of tubular components.

Gu, Dongdong; Shen, Yifu

2009-10-01

148

Tensile properties of 21-6-9 stainless steel at elevated temperatures  

SciTech Connect

Tensile properties of Type 21-6-9 austenitic stainless steel were measured at temperatures ranging from ambient to 1200C at a strain rate of 6.67 {times} 10{sup {minus}4} s{sup {minus}1}. Data show that yield stress decreases rapidly from room temperature to about 300C, followed by a nearly constant value in the `plateau` region from 300 to 600C. Beyond the ``plateau,`` there is more rapid drop in yield stress as temperature increases. Ultimate tensile stress shows a plateau between 300 and 700 C, which may be caused by solutes. 21-6-9 stainless steel has excellent ductility, with the elongation to failure ranging from 55 to 95%. It appears that there is a local minimum in the ductility at approximately 700C. Results are compared with earlier results of Kassner and co-workers.

Torres, S.G.; Henshall, G.A.

1993-10-01

149

TRITIUM AGING EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF FORGED STAINLESS STEEL  

SciTech Connect

The fracture toughness properties of Type 21-6-9 stainless steel were measured for forgings in the unexposed, hydrogen-exposed, and tritium-exposed-and-aged conditions. Fracture toughness samples were cut from conventionally-forged and high-energy-rate-forged forward-extruded cylinders and mechanically tested at room temperature using ASTM fracture-toughness testing procedures. Some of the samples were exposed to either hydrogen or tritium gas (340 MPa, 623 K) prior to testing. Tritium-exposed samples were aged for up to seven years and tested periodically in order to measure the effect on fracture toughness of {sup 3}He from radioactive tritium decay. The results show that hydrogen-exposed and tritium-exposed samples had lower fracture- toughness values than unexposed samples and that fracture toughness decreased with increasing decay {sup 3}He content. Forged steels were more resistant to the embrittling effects of tritium and decay {sup 3}He than annealed steels, although their fracture-toughness properties depended on the degree of sensitization that occurred during processing. The fracture process was dominated by microvoid nucleation, growth and coalescence; however, the size and spacing of microvoids on the fracture surfaces were affected by hydrogen and tritium with the lowest-toughness samples having the smallest microvoids and finest spacing.

Morgan, M

2008-04-14

150

Effect of phosphorus on the structure and properties of 5Kh20N4AG9 steel  

Microsoft Academic Search

1.Alloying austenitic chromium-manganese-nickel steel 5Kh20N4AG9 with phosphorus in amounts up to 0.2% improves the mechanical properties of the steel at elevated and room temperatures.2.The best combination of mechanical properties is obtained by alloying with 0.2% P and up to 1% Mo.3.The addition of about 0.2% P increases the intensity of precipitation hardening (carbides of the Cr23C6 type and Cr2N nitrides)

K. A. Verner; V. D. Zelenova; V. M. Doronin; A. F. Buinov

1967-01-01

151

Mechanical property and irradiation damage of China Low Activation Martensitic (CLAM) steel  

NASA Astrophysics Data System (ADS)

China Low Activation Martensitic (CLAM) steel is being studied to develop the structural materials for a fusion reactor, which has been designed based on the well-known 9Cr1.5WVTa steel. The effect of tempering temperature on hardness and microstructure of CLAM steel was studied. The strength of CLAM steel increased by adding silicon, and the ductility remained constant. Conversely, while CLAM steel maintained good ductility with the addition of yttrium, its tensile strengths were greatly degraded. Behaviors under electron irradiation of CLAM steel were examined using the high voltage electron microscope. Electron irradiation at 450C formed many voids in CLAM steel with basic composition, whereas CLAM with silicon steel did not change the microstructure significantly.

Zhu, YanYong; Wan, FaRong; Gao, Jin; Han, WenTuo; Huang, YiNa; Jiang, ShaoNing; Qiao, JianSheng; Zhao, Fei; Yang, ShanWu; Ohnuki, Somei; Hashimoto, Naoyuki

2012-11-01

152

Correlations between microstructure and mechanical properties during PWHT of TMCP steel weld HAZ  

Microsoft Academic Search

This paper describes an investigation of the correlation between HAZ microstructures amd mechanical properties in the post?weld heat treatment (PWHT) of two types of thermomechanical control process steels (TMCP steels), especially the relationship between the stress relaxation behaviour and high?temperature deformability. Simulated weld heat treatment was performed with a welding thermal cycle simulator at a maximum temperature of 1623 K.

M. Nakamura; H. Horie; K. Tagashira; H. Kawashima

1996-01-01

153

THE EFFECTS OF HYDROGEN, TRITIUM, AND HEAT TREATMENT ON THE DEFORMATION AND FRACTURE TOUGHNESS PROPERTIES OF STAINLESS STEEL  

SciTech Connect

The deformation and fracture toughness properties of forged stainless steels pre-charged with tritium were compared to the deformation and fracture toughness properties of the same steels heat treated at 773 K or 873 K and precharged with hydrogen. Forged stainless steels pre-charged with tritium exhibit an aging effect: Fracture toughness values decrease with aging time after precharging because of the increase in concentration of helium from tritium decay. This study shows that forged stainless steels given a prior heat treatment and then pre-charged with hydrogen also exhibit an aging effect: Fracture toughness values decrease with increasing time at temperature. A microstructural analysis showed that the fracture toughness reduction in the heat-treated steels was due to patches of recrystallized grains that form within the forged matrix during the heat treatment. The combination of hydrogen and the patches of recrystallized grains resulted in more deformation twinning. Heavy deformation twinning on multiple slip planes was typical for the hydrogen-charged samples; whereas, in the non-charged samples, less twinning was observed and was generally limited to one slip plane. Similar effects occur in tritium pre-charged steels, but the deformation twinning is brought on by the hardening associated with decay helium bubbles in the microstructure.

Morgan, M.; Tosten, M.; Chapman, G.

2013-09-06

154

Microstructural Characterization and Mechanical Performance of Hot Work Tool Steel Processed by Selective Laser Melting  

NASA Astrophysics Data System (ADS)

Microstructural characterization of hot work tool steel processed by selective laser melting was carried out. The findings shed light on the interrelationship between processing parameters and the microstructural evolution. It was found that the microstructure after layer-wise processing partially consists of metastable-retained austenite which transforms to martensite in a subsequent tensile test. This improves the mechanical properties of the hot work tool steel enabling direct application.

Holzweissig, Martin Joachim; Taube, Alexander; Brenne, Florian; Schaper, Mirko; Niendorf, Thomas

2015-01-01

155

Corrosion properties of S-phase layers formed on medical grade austenitic stainless steel.  

PubMed

The corrosion properties of S-phase surface layers formed in AISI 316LVM (ASTM F138) and High-N (ASTM F1586) medical grade austenitic stainless steels by plasma surface alloying with nitrogen (at 430C), carbon (at 500C) and both carbon and nitrogen (at 430C) has been investigated. The corrosion behaviour of the S-phase layers in Ringer's solutions was evaluated using potentiodynamic and immersion corrosion tests. The corrosion damage was evaluated using microscopy, hardness testing, inductive coupled plasma mass spectroscopy and X-ray diffraction. The experimental results have demonstrated that low-temperature nitriding, carburising and carbonitriding can improve the localised corrosion resistance of both industrial and medical grade austenitic stainless steels as long as the threshold sensitisation temperature is not reached. Carburising at 500C has proved to be the best hardening treatment with the least effect on the corrosion resistance of the parent alloy. PMID:22160745

Buhagiar, Joseph; Dong, Hanshan

2012-02-01

156

Influence of laser hardening and resulting microstructure on fatigue properties of carbon steels  

NASA Astrophysics Data System (ADS)

Cylindrical specimens of a CSN 12050 carbon steel, equivalent to the UNS G 10420 steel, with two different initial microstructures, normalized and heat treated, were surface processed without melting by a 2.5 kW, CO2 laser to study the effects of laserbeam hardening and resulting microstructure on fatigue properties and mechanisms. Two configurations of circumferential laser passes were made, resulting in one and three separate surface hardened lines, respectively. Fatigue resistance was studied using alternating bend tests. A detailed metallographic study and x-ray measurements of surface stresses were carried out. It was shown that the laser beam hardening under different conditions either reduced or slightly improved the fatigue life.

Cerny, I.; Frbacher, I.; Linhart, V.

1998-06-01

157

Creation of superhydrophobic stainless steel surfaces by acid treatments and hydrophobic film deposition.  

PubMed

In this work, we present a method to render stainless steel surfaces superhydrophobic while maintaining their corrosion resistance. Creation of surface roughness on 304 and 316 grade stainless steels was performed using a hydrofluoric acid bath. New insight into the etch process is developed through a detailed analysis of the chemical and physical changes that occur on the stainless steel surfaces. As a result of intergranular corrosion, along with metallic oxide and fluoride redeposition, surface roughness was generated on the nano- and microscales. Differences in alloy composition between 304 and 316 grades of stainless steel led to variations in etch rate and different levels of surface roughness for similar etch times. After fluorocarbon film deposition to lower the surface energy, etched samples of 304 and 316 stainless steel displayed maximum static water contact angles of 159.9 and 146.6, respectively. However, etching in HF also caused both grades of stainless steel to be susceptible to corrosion. By passivating the HF-etched samples in a nitric acid bath, the corrosion resistant properties of stainless steels were recovered. When a three step process was used, consisting of etching, passivation and fluorocarbon deposition, 304 and 316 stainless steel samples exhibited maximum contact angles of 157.3 and 134.9, respectively, while maintaining corrosion resistance. PMID:22913317

Li, Lester; Breedveld, Victor; Hess, Dennis W

2012-09-26

158

Corrosion properties of oxide dispersion strengthened steels in super-critical water environment  

NASA Astrophysics Data System (ADS)

The effects of alloying elements on corrosion resistance in super critical pressurized water (SCPW) have been investigated to develop corrosion resistant oxide dispersion strengthened (ODS) steels. Corrosion tests were performed in a SCPW (783 K, 25 MPa) environment. Weight gain was measured after exposure to the SCPW. For the improvement of corrosion-resistance, the effects of chromium, aluminum, and yttrium on the corrosion behavior were investigated. The 9-12 wt%Cr ODS steels showed almost similar corrosion behavior with the ordinary ferritic/martensitic steel in the SCPW. However, the addition of high chromium (>13 wt%) and aluminum (4.5 wt%) are very effective to suppress the corrosion in the SCPW. Anodic polarization experiments revealed that the passive current of the ODS steels are lower than the ordinary ferritic/martensitic steels. Addition of aluminum improves the Charpy impact property of the ODS steels.

Cho, H. S.; Kimura, A.; Ukai, S.; Fujiwara, M.

2004-08-01

159

Effect of oxygen on the mechanical properties and character of failure of powder steel 40N3M  

Microsoft Academic Search

An examination was made of the origin of the different forms of oxygen, since it requires individual detailed study, and the effect of oxygen on the mechanical properties of steel 40N3M was investigated as a function of its overall content in this steel. It is shown that oxygen sprayed and deformed steels lowers the mechanical properties even when its content

T. P. Moskvina; A. P. Gulyaev

1988-01-01

160

Influence of Prior Fatigue Damage on Tensile Properties of 316L(N) Stainless Steel and Modified 9Cr-1Mo Steel  

NASA Astrophysics Data System (ADS)

In the current study, the effect of prior low-cycle fatigue (LCF) damage on the tensile properties of 316L(N) stainless steel (SS) and modified 9Cr-1Mo steel were systematically investigated. The LCF tests were interrupted at 5, 10, 30, and 50 pct of the total fatigue life followed by tensile tests on the same specimens at the same strain rate (3 10-3 s-1) and temperatures of 300 K, 823 K, and 873 K (27 C, 550 C, and 600 C). Prior strain cycling at elevated temperatures had remarkable effect on the tensile properties of both cyclically hardening and cyclically softening materials. An exponential relationship between the yield stress and the amount of pre-strain cycles is obtained for both the materials. The initial drastic change in the yield strength values up to 10 pct of fatigue life may be due to the microstructural changes that lead to hardening or softening in 316L(N) SS and modified 9Cr-1Mo steel, respectively. Saturation in the yield strength values beyond 10 pct of fatigue life has practical importance for remnant fatigue life assessment. Evolution of fatigue damage in both the 316L(N) SS and modified 9Cr-1Mo steel was analyzed using the surface replica technique.

Mariappan, K.; Shankar, Vani; Sandhya, R.; Mathew, M. D.; Bhaduri, A. K.

2014-12-01

161

Influence of Prior Fatigue Damage on Tensile Properties of 316L(N) Stainless Steel and Modified 9Cr-1Mo Steel  

NASA Astrophysics Data System (ADS)

In the current study, the effect of prior low-cycle fatigue (LCF) damage on the tensile properties of 316L(N) stainless steel (SS) and modified 9Cr-1Mo steel were systematically investigated. The LCF tests were interrupted at 5, 10, 30, and 50 pct of the total fatigue life followed by tensile tests on the same specimens at the same strain rate (3 10-3 s-1) and temperatures of 300 K, 823 K, and 873 K (27 C, 550 C, and 600 C). Prior strain cycling at elevated temperatures had remarkable effect on the tensile properties of both cyclically hardening and cyclically softening materials. An exponential relationship between the yield stress and the amount of pre-strain cycles is obtained for both the materials. The initial drastic change in the yield strength values up to 10 pct of fatigue life may be due to the microstructural changes that lead to hardening or softening in 316L(N) SS and modified 9Cr-1Mo steel, respectively. Saturation in the yield strength values beyond 10 pct of fatigue life has practical importance for remnant fatigue life assessment. Evolution of fatigue damage in both the 316L(N) SS and modified 9Cr-1Mo steel was analyzed using the surface replica technique.

Mariappan, K.; Shankar, Vani; Sandhya, R.; Mathew, M. D.; Bhaduri, A. K.

2015-02-01

162

Phase transformation and impact properties in the experimentally simulated weld heat-affected zone of a reduced activation ferritic/martensitic steel  

NASA Astrophysics Data System (ADS)

In this work, the phase transformation and impact properties in the weld heat-affected zone (HAZ) of a reduced activation ferritic/martensitic (RAFM) steel are investigated. The HAZs were experimentally simulated using a Gleeble simulator. The base steel consisted of tempered martensite through normalizing at 1000 C and tempering at 750 C, while the HAZs consisted of martensite, ?-ferrite and a small volume of autotempered martensite. The impact properties using a Charpy V-notch impact test revealed that the HAZs showed poor impact properties due to the formation of martensite and ?-ferrite as compared with the base steel. In addition, the impact properties of the HAZs further deteriorated with an increase in the ?-ferrite fraction caused by increasing the peak temperature. The impact properties of the HAZs could be improved through the formation of tempered martensite after post weld heat treatment (PWHT), but they remained lower than that of the base steel because the ?-ferrite remained in the tempered HAZs.

Moon, Joonoh; Lee, Chang-Hoon; Lee, Tae-Ho; Jang, Min-Ho; Park, Min-Gu; Han, Heung Nam

2014-12-01

163

Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components  

Microsoft Academic Search

The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950`s are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials

R. L. Sindelar; G. R. Jr. Caskey

1991-01-01

164

Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components  

Microsoft Academic Search

The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950's are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials

R. L. Sindelar; G. R. Jr. Caskey

1991-01-01

165

Helium effects on creep properties of Fe-14CrWTi ODS steel at 650 C  

NASA Astrophysics Data System (ADS)

In the present paper, the effects of helium on creep properties of Fe-14CrWTi ODS steel were studied by in-beam and post He-implantation creep tests. In-situ creep was performed in an in-beam creep device under uniaxial tensile stresses from 350 to 370 MPa during homogeneous helium implantation. Helium ions of energies varying from 0 to 25 MeV were implanted at a rate of 6 10-3 appm/s (corresponding to a displacement dose rate of 1.5 10-6 dpa/s). The average temperature was controlled to 650 C within 2 C. In addition, post He-implantation creep tests were conducted at 650 C as well. Subsequently, fracture surfaces and helium bubble evolution were studied in detail by SEM and TEM observations, respectively. Preliminary creep results show that helium slightly shortens the creep life time of ODS steel at 650 C. Fracture surfaces of reference as well as implanted specimens, show areas with various grades of deformation. Areas of highest deformation can be interpreted as necking, while areas of low deformation show in helium implanted specimens a more granular structure. The results are discussed in terms of possible embrittlement of ODS steels by helium.

Chen, J.; Jung, P.; Rebac, T.; Duval, F.; Sauvage, T.; de Carlan, Y.; Barthe, M. F.

2014-10-01

166

Microstructure and Mechanical Properties of 316L Stainless Steel Filling Friction Stir-Welded Joints  

NASA Astrophysics Data System (ADS)

Keyhole left at 316L stainless steel friction stir welding/friction stir processing seam was repaired by filling friction stir welding (FFSW). Both metallurgical and mechanical bonding characteristics were obtained by the combined plastic deformation and flow between the consumable filling tool and the wall of the keyhole. Two ways based on the original conical and modified spherical keyholes, together with corresponding filling tools and process parameters were investigated. Microstructure and mechanical properties of 316L stainless steel FFSW joints were evaluated. The results showed that void defects existed at the bottom of the refilled original conical keyhole, while excellent bonding interface was obtained on the refilled modified spherical keyhole. The FFSW joint with defect-free interface obtained on the modified spherical keyhole fractured at the base metal side during the tensile test due to microstructural refinement and hardness increase in the refilled keyhole. Moreover, no ? phase but few Cr carbides were formed in the refilled zone, which would not result in obvious corrosion resistance degradation of 316L stainless steel.

Zhou, L.; Nakata, K.; Tsumura, T.; Fujii, H.; Ikeuchi, K.; Michishita, Y.; Fujiya, Y.; Morimoto, M.

2014-10-01

167

Fracture properties of a neutron-irradiated stainless steel submerged arc weld cladding overlay  

SciTech Connect

The ability of stainless steel cladding to increase the resistance of an operating nuclear reactor pressure vessel to extension of surface flaws depends greatly on the properties of the irradiated cladding. Therefore, weld overlay cladding irradiated at temperatures and fluences relevant to power reactor operation was examined. The cladding was applied to a pressure vessel steel plate by the submerged arc, single-wire, oscillating-electrode method. Three layers of cladding provided a thickness adequate for fabrication of test specimens. The first layer was type 309, and the upper two layers were type 308 stainless steel. The type 309 was diluted considerably by excessive melting of the base plate. Specimens were taken from near the base plate-cladding interface and also from the upper layers. Charpy V-notch and tensile specimens were irradiated at 288/sup 0/C to a fluence of 2 x 10/sup 23/ neutrons/m/sup 2/ (>1 MeV). 10 refs., 16 figs., 4 tabs.

Corwin, W.R.; Berggren, R.G.; Nanstad, R.K.

1984-01-01

168

LITERATURE SURVEY OF GASEOUS HYDROGEN EFFECTS ON THE MECHANICAL PROPERTIES OF CARBON AND LOW ALLOY STEELS  

SciTech Connect

Literature survey has been performed for a compendium of mechanical properties of carbon and low alloy steels following hydrogen exposure. The property sets include yield strength, ultimate tensile strength, uniform elongation, reduction of area, threshold stress intensity factor, fracture toughness, and fatigue crack growth. These properties are drawn from literature sources under a variety of test methods and conditions. However, the collection of literature data is by no means complete, but the diversity of data and dependency of results in test method is sufficient to warrant a design and implementation of a thorough test program. The program would be needed to enable a defensible demonstration of structural integrity of a pressurized hydrogen system. It is essential that the environmental variables be well-defined (e.g., the applicable hydrogen gas pressure range and the test strain rate) and the specimen preparation be realistically consistent (such as the techniques to charge hydrogen and to maintain the hydrogen concentration in the specimens).

Lam, P; Andrew Duncan, A; Robert Sindelar, R; Thad Adams, T

2009-04-27

169

LITERATURE SURVEY OF GASEOUS HYDROGEN EFFECTS ON THE MECHANICAL PROPERTIES OF CARBON AND LOW ALLOY STEELS  

SciTech Connect

Literature survey has been performed for a compendium of mechanical properties of carbon and low alloy steels following hydrogen exposure. The property sets include yield strength, ultimate tensile strength, uniform elongation, reduction of area, threshold stress intensity factor, fracture toughness, and fatigue crack growth. These properties are drawn from literature sources under a variety of test methods and conditions. However, the collection of literature data is by no means complete, but the diversity of data and dependency of results in test method is sufficient to warrant a design and implementation of a thorough test program. The program would be needed to enable a defensible demonstration of structural integrity of a pressurized hydrogen system. It is essential that the environmental variables be well-defined (e.g., the applicable hydrogen gas pressure range and the test strain rate) and the specimen preparation be realistically consistent (such as the techniques to charge hydrogen and to maintain the hydrogen concentration in the specimens).

Lam, P; Robert Sindelar, R; Thad Adams, T

2007-04-18

170

Strain-Magnetization Properties and Domain Structures of Silicon Steel Sheets  

NASA Astrophysics Data System (ADS)

The effects of tensile stress and strain on magnetization and magnetic domains in silicon steel sheets were investigated. The magnetization of elastic deformation regions decreased with increase of strain and the strain-magnetization properties of plastic deformation regions under stress showed peculiar characteristics. The magnetization increased with decreasing strain. We observed Lancet and other domains in a sample, especially around the boundary of crystal, after removing stress applied to a plastic deformation region. This phenomenon can be explained by changes in the domain structures, which were partly observed. This results obtained in this investigation can be applied to the nondestructive detection of fatigue in metallic magnetic materials.

Notoji, Atsushi; Saito, Akihiko; Hayakawa, Motozo

171

Properties of seamless steel pipes and nondestructive testing  

Microsoft Academic Search

Flaw detection in seamless steel pipes used in fossil and nuclear power ; plants and petrochemical plants is reviewed. The methods discussed include eddy ; current, magnetic, ultrasonic, fluorescent substance penetration, and dye ; penetration. (TFD);

Hamada

1973-01-01

172

Effect of grain size on the mechanical properties of dual phase Fe/Si/C steels  

SciTech Connect

For an Fe/2Si/0.1C steel with an intermediate quenching heat treatment, it was found that as the prior austenite grain size is refined, significant improvements in total elongation, reduction in area and impact toughness can be achieved, while uniform elongation, yield and tensile strengths are not affected. These improvements are analyzed in terms of microstructure and fracture characteristics. The cleavage cracks propagate nearly straight without deviation at the ferrite/martensite interfaces within the sub-units of the DFM structure, but change their path at high angle sub-unit boundaries. The crack is less likely to be deflected at the ferrite/martensite interface because the interface is coherent. Comparison of optical micrographs and SEM fractographs has shown that there is close agreement between the sub-unit size and cleavage facet size. The observations lead to the conclusion that the sub-unit size is the basic microstructure unit controlling the fracture behavior of DFM steels produced by the intermediate quenching heat treatment. A controlled rolling process was undertaken to obtain grain refined DFM steels. Results showed that this produces micro-duplex structures with attractive mechanical properties in an economicl way.

Ahn, J.H.

1983-08-01

173

Joining of aluminum alloy to steel by friction stir welding  

Microsoft Academic Search

The authors tried to butt-weld an aluminum alloy plate to a mild steel plate by friction stir welding, and investigated the effects of a pin rotation speed, the position for the pin axis to be inserted on the tensile strength and the microstructure of the joint. The behavior of the oxide film on the faying surface of the steel during

Takehiko Watanabe; Hirofumi Takayama; Atsushi Yanagisawa

2006-01-01

174

Functional properties of laser modified surface of tool steel  

Microsoft Academic Search

Purpose: Investigations include alloying the surface of X40CrMoV5-1 hot-work tool steel with tungsten carbide using a high power diode laser (HPDL). Design\\/methodology\\/approach: The structural mechanism of surface layer development was determined and the effect of alloying parameters, gas protection method, and thickness of paste layer applied onto the steel surface on structure refinement and influence of these factors on the

M. Bonek; L. A. Dobrza?ski

175

Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Early Detection of Steel Rebar Corrosion by Acoustic Emission  

E-print Network

Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Early Detection of Steel Rebar Corrosion by Acoustic Emission Monitoring Alan D. Zdunek and David Prine BIRL Industrial Research, Evanston, IL 60201 Paper No. 547 presented at CORROSION95, the NACE International Annual Conference

176

Magnetic Study of Martensitic Transformation in Austenitic Stainless Steel by Low Field Hysteresis Loops Analysis  

NASA Astrophysics Data System (ADS)

Magnetic method has been used to evaluate the volume percentage of ?' martensitic phase in austenitic stainless steels by measuring saturation magnetization, and it is said to be a candidate NDE method. However, nondestructive detection of saturation magnetization without high magnetic field is difficult. In the current work, we present a NDE method for evaluating the magnetic properties of strain induced ?' martensitic phase. Low field hysteresis loops of an austenitic stainless steels type SUS 304 after cold rolling were measured by using a yoke sensor. The results show that the initial permeability ?i and the relative coercive field Hcl calculated by low field hysteresis loop analysis keep monotonic relation with saturation magnetization and coercive force measured by VSM, respectively. By this method, it is possible to characterize the volume content and particle properties of ?' martensitic phase in stainless steels.

Zhang, Lefu; Takahashi, Seiki; Kamada, Yasuhiro; Kikuchi, Hiroaki; Mumtaz, Khalid; Ara, Katsuyuki; Sato, Masaya

2005-04-01

177

Structure and mechanical properties of the 03Kh14GNF steel after deformation and annealing  

NASA Astrophysics Data System (ADS)

It has been shown that the annealing of cold-worked 03Kh14GNF steel is accompanied by several strengthening and softening processes that take place in different temperature intervals. Therefore, the temperature dependence of its hardness has a complicated form; i.e., it contains several maxima and minima. The following processes should be noted: recovery and recrystallization of ? ferrite, precipitation of M 2(CN) carbonitrides and M 23C6 carbides from the ? martensite, their dissolution in the ? phase, the formation of austenite with different stability, polygonization of the ? martensite, etc. Tempering for 30 h can produce the level of mechanical properties required according to technical specifications for two processing regimes. These regimes are the annealing at 680C and at 600C, but in the second case the high plasticity is probably caused by the formation of a highly stable austenite that is retained down to room temperature. However, the degree of plasticity of this ? phase at room and lower temperatures is unknown. After annealing at 660C, the steel does not achieve the level of ultimate strength of 480 N/mm2, which is required by the technical specifications. However, since the relative elongation of 35% exceeds the required magnitude, the required level of mechanical properties can apparently be produced by a decrease in the duration of annealing to 20-25 h.

Shaburov, D. V.; Valitov, V. G.; Mirzaev, D. A.; Yakovleva, I. L.; Kirpichnikov, M. S.; Vetoshkina, T. Yu.

2009-04-01

178

Relationship between mechanical and magnetic properties in cold rolled low carbon steel  

NASA Astrophysics Data System (ADS)

Structure-sensitive properties of minor hysteresis loops have been compared with Vickers hardness and ductile-brittle transition temperature (DBTT) obtained by Charpy impact test for cold rolled low carbon steel. Minor loops were measured with increasing magnetic field amplitude, step by step, and were analyzed in connection with the rolling reduction. We found that minor-loop coefficients deduced from relations between minor-loop parameters increase with increasing rolling reduction and have a simple relationship with both mechanical properties, Vickers hardness, and DBTT. We also found that these coefficients have a linear relation with coercive force obtained by the major loop. The present analysis method using minor loops is highly effective for nondestructive evaluation of ductile-brittle transition, in terms of the high sensitivity to lattice defects as well as low measurement field.

Takahashi, S.; Kobayashi, S.; Kikuchi, H.; Kamada, Y.

2006-12-01

179

Effects of an inorganic coating on the structure and magnetic properties of a 1 wt. % silicon steel  

NASA Astrophysics Data System (ADS)

Various organic and inorganic coatings are used for electrical steels to improve their punchability and interlaminar resistance. However, very little information is available in the literature on the effect of these coatings on structure and magnetic properties of electrical steels. In this study, the influence of a commercial mono-aluminum-phosphate coating was investigated for a 1.0 wt. % silicon steel. It was noted that this type of coating is responsible for the following: (1) rate of decarburization is essentially unaffected, (2) the growth of subsurface oxide is substantially reduced, (3) 1.5 T permeability is improved via reduction in the subsurface oxide layer, and (4) core loss is decreased by reducing anomalous loss. A possible mechanism to suppress the subsurface oxidation by phosphorus segregation is suggested on the basis of results obtained by AES analysis.

Rastogi, Prabhat K.; Kim, Yong-Wu

1985-04-01

180

Study of TRIP-Aided Bainitic Ferritic Steels Produced by Hot Press Forming  

NASA Astrophysics Data System (ADS)

A study is reported to produce high strength ductile steels by controlled cooling following hot press forming, instead of quenching, as is practiced in the traditional press hardened steels. Heat treatments of several specially designed low carbon steels were carried out by interrupting the fast cooling from the austenization temperature at temperatures between T 0 and Ms and then cooling in controlled rates to room temperature. The effect of the interrupt temperature and the cooling rate afterward on the microstructures and tensile properties was studied. The microstructures were characterized using dilatometry, optical microscopy, X-ray diffraction, and TEM. A multi-phase microstructure including bainite, martensite, and retained austenite was obtained in the simulated hot press forming process. Volume fraction bainite was found to increase with an increase in interrupt temperature and a decrease in cooling rate. Structure-property correlations of the studied steels heat treated at different conditions were developed. Improved tensile properties were obtained by controlling the interrupt temperature and cooling rate which produced an optimum bainite content of 60 to 75 pct and retained austenite. Unfortunately, the bainite in the simulated samples was not completely carbide free even though the steels contained about 1.6 wt pct of Si.

Chen, Shangping; Rana, Radhakanta; Lahaije, Chris

2014-04-01

181

Recycling zinc by dezincing steel scrap  

SciTech Connect

In response to the worldwide increase in consumption of galvanized steel for automobiles in the last fifteen years, and the increased cost of environmental compliance associated with remelting larger quantities of galvanized steel scrap, a process is being developed to separate and recover the steel and zinc from galvanized ferrous scrap. The zinc is dissolved from the scrap in hot caustic using anodic assistance and is recovered electrolytically as dendritic powder. The designed ferrous scrap is rinsed and used directly. The process is effective for zinc, lead, and aluminum removal on loose and baled scrap and on all types of galvanized steel. The process has been pilot tested in Hamilton, Ontario for batch treatment of 900 tonnes of mostly baled scrap. A pilot plant in East Chicago, Indiana has designed in a continuous process mode 900 tonnes of loose stamping plant scrap; this scrap typically has residual zinc below 0.1% and sodium dragout below 0.001%. This paper reviews pilot plant performance and the economics of recycling galvanized steel and recovering zinc using a caustic process.

Dudek, F.J.; Daniels, E.J. [Argonne National Lab., IL (United States); Morgan, W.A. [Metal Recovery Industries, Inc., East Chicago, IN (United States)

1995-06-01

182

Microstructural Features Controlling Mechanical Properties in Nb-Mo Microalloyed Steels. Part II: Impact Toughness  

NASA Astrophysics Data System (ADS)

The present paper is the final part of a two-part paper where the influence of coiling temperature on the final microstructure and mechanical properties of Nb-Mo microalloyed steels is described. More specifically, this second paper deals with the different mechanisms affecting impact toughness. A detailed microstructural characterization and the relations linking the microstructural parameters and the tensile properties have already been discussed in Part I. Using these results as a starting point, the present work takes a step forward and develops a methodology for consistently incorporating the effect of the microstructural heterogeneity into the existing relations that link the Charpy impact toughness to the microstructure. In conventional heat treatments or rolling schedules, the microstructure can be properly described by its mean attributes, and the ductile-brittle transition temperatures measured by Charpy tests can be properly predicted. However, when different microalloying elements are added and multiphase microstructures are formed, the influences of microstructural heterogeneity and secondary hard phases have to be included in a modified equation in order to accurately predict the DB transition temperature in Nb and Nb-Mo microalloyed steels.

Isasti, Nerea; Jorge-Badiola, Denis; Taheri, Mitra L.; Uranga, Pello

2014-10-01

183

Effect of silicon and germanium on the structure and properties of cast high-speed steel  

Microsoft Academic Search

The effect of silicon and germanium additives on the structure and properties of cast cobalt tungsten-molybdenum high-speed\\u000a steel of type R6M5K5 is studied. Results of metallographic and x-ray diffraction analyses of experimental steels after casting,\\u000a annealing, quenching, and tempering are discussed. The interrelation of the structural parameters, the degree of contamination\\u000a of the metal with nonmetallic inclusions, and mechanical parameters

A. S. Chaus

2009-01-01

184

Mechanical properties of steel fiber-reinforced, high-strength, lightweight concrete  

Microsoft Academic Search

This paper presents basic information on the mechanical properties of steel fiber-reinforced, high-strength, lightweight concrete with compressive and flexural strengths up to 85.4 MPa and 11.8 MPa, respectively. The influence of steel fiber on modulus of elasticity and Poisson's ratio of concrete are investigated, and flexural fracture toughness is calculated. Test results show that the effect of fiber volume fraction

Jianming Gao; Wei Sun; Keiji Morino

1997-01-01

185

Factors influencing fretting fatigue properties of plasma-nitrided low alloy steel  

Microsoft Academic Search

709M40 steel samples were plasma-nitrided under various processing conditions. Fretting fatigue tests were carried out with a Whler rotating bending fatigue machine, using SN curves to evaluate the fretting fatigue properties of the untreated and plasma-nitrided steel. The influences of such structural factors as compound layer, case depth, case hardness and compressive residual stress on the fretting fatigue behaviour of

C. X Li; Y Sun; T Bell

2000-01-01

186

Effect of chromium, tungsten, tantalum, and boron on mechanical properties of 59CrWVTaB steels  

Microsoft Academic Search

The CrWVTa reduced-activation ferritic\\/martensitic steels use tungsten and tantalum as substitutes for molybdenum and niobium in the CrMoVNb steels that the reduced-activation steels replaced as candidate materials for fusion applications. Studies were made to determine the effect of W, Ta, and Cr composition on the tensile and Charpy properties of the CrWVTa; steels with 5%, 7%, and 9% Cr with

R. L Klueh; D. J Alexander; M. A Sokolov

2002-01-01

187

Oxidation resistance in LBE and air and tensile properties of ODS ferritic steels containing Al/Zr elements  

NASA Astrophysics Data System (ADS)

The effects of Al and Zr addition on improvement of oxidation resistance in lead-bismuth eutectic (LBE) and in air as well as the tensile properties were investigated for the oxide dispersion strengthened (ODS) steels. The 16Cr-4Al-0.8Zr-ODS steel samples were fabricated by a sol-gel method combining with spark plasma sintering technique. The tests in LBE at 600 C for 1000 h indicate the good oxidation resistance comparing with the specimens without Zr/Al elements. The samples also exhibit superior oxidation resistance in air due to formation of dense and continuous aluminum oxide film. Minor Zr addition prevents the Al element induced coarsening of the oxide particles in ODS steels and significantly improves the ultimate tensile stress and total elongation of the samples.

Gao, R.; Xia, L. L.; Zhang, T.; Wang, X. P.; Fang, Q. F.; Liu, C. S.

2014-12-01

188

Diffusion welding parameters and mechanical properties of martensitic chromium steels  

Microsoft Academic Search

To develop and qualify diffusion welding for fabrication of precise high stressed components of fusion reactors, a comprehensive test program was carried out using the martensitic chromium steels OPTIFER-IV and MANET-II. Metallographical and mechanical examinations served to determine the welding quality. The main result is that with a welding pressure of about 50 MPa and a surface roughness of few

K. Schleisiek; T Lechler; L Schfer; P Weimar

2000-01-01

189

Oxygen effect on low-alloy steel weld metal properties  

SciTech Connect

It is shown that the weld metal oxygen content in submerged arc low-alloy steel welds, as well as in low-carbon steel welds is dependent on the concentration of oxides decomposed at low temperatures in a weld pool slag phase. The oxygen is mainly in the form of fine dispersed oxide inclusions of less than 0.03 [mu]m. Differentiated evaluation of silicon reduction effects in submerged arc welded low-alloy steels revealed that weld metal brittle fracture strength depends to a considerable degree on total weld metal oxide inclusion content than on silicon increment in the weld. Therefore, the increase of weld metal brittle fracture susceptibility with the growth of weld oxide inclusion content is important to know. Welds with lowered oxygen content [0] [<=] 0.02% also display the tendency to decrease in plasticity because (1) the ferritic-pearlitic matrix of improved purity is likely to generate unbalanced structures on cooling and, (2) when there are no oxide inclusions, the shape of sulfur and phosphor precipitation from the melt changes from globular to film-like. Optimal low-alloy steel weld metal oxygen content is defined in the range of 0.02-0.035.

Potapov, N.N. (Scientific Industrial Corp., of Machinery Technology, Moscow (Russian Federation). Welding Dept.)

1993-08-01

190

Effect of Partial Replacement of Si with Al on the Microstructures and Mechanical Properties of 1000 MPa TRIP Steels  

NASA Astrophysics Data System (ADS)

Two newly synthesized C-Mn-Si-Mo-Nb transformation-induced plasticity (TRIP) steels with and without Al addition were designed in order to achieve significant improvements in the mechanical properties. The effect of substitution of Si by Al on tensile properties and the microstructure of cold-rolled C-Mn-Si TRIP steel was investigated under different heat treatments. It was shown that a complex ultrafine microstructure composed of different phases was formed and two types of morphology for ferrite were detected (equiaxial and polygonal). The distribution of alloying elements was observed by using electron probe microanalysis. It was clear that C was concentrated in the retained austenite (RA) and small M/A (austenite/martensite) islands. The Al addition facilitated the formation of polygonal ferrite and increased the stability of the RA. The strain-hardening behavior was studied in detail. All the investigated specimens showed a very high strain-hardening exponent (instantaneous n) but their strain dependence was different. For the C-Mn-Si-Mo-Nb TRIP steel, the maximum n value was achieved when the strain was only about 0.04, while the n value of the Al substituted TRIP steel increased gradually until strains in the range of 0.07-0.10 were reached and the maximum value was achieved. As a result, the elongations of the steel with Al addition increased considerably without obvious deterioration of strength. It was the first time to find microtwinned martensite located between ferrite and bainitic ferrite after tensile deformation in the low alloy TRIP steel with Al.

Wang, Chao; Ding, Hua; Zhang, Jun; Di, Huafang

2014-11-01

191

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure  

Microsoft Academic Search

The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light and electron microscopy, electron probe microanalysis, and Mssbauer spectroscopy. The mechanical properties were investigated by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The Beta-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron microscopy

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

1994-01-01

192

Heat treatment of investment cast PH 13-8 Mo stainless steel: Part I. Mechanical properties and microstructure  

Microsoft Academic Search

The microstructure of investment cast PH 13-8 Mo stainless steel heat-treated to various conditions was studied using light\\u000a and electron microscopy, electron probe microanalysis, and M?ssbauer spectroscopy. The mechanical properties were investigated\\u000a by using uniaxial tensile testing, hardness testing, and Charpy impact testing. The?-NiAl strengthening precipitates, though detectable by electron diffraction, were difficult to resolve by transmission electron\\u000a microscopy (TEM)

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

1994-01-01

193

10. DETAIL, SOUTHEAST SPAN THROUGH CANAL, VIEW BLOCKED BY STEEL, ...  

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

10. DETAIL, SOUTHEAST SPAN THROUGH CANAL, VIEW BLOCKED BY STEEL, CLAD COUNTER WEIGHT, WATER SPAN RAISED OUT OF VIEW - Cape Cod Canal Lift Bridge, Spanning Cape Cod Canal, Buzzards Bay, Barnstable County, MA

194

Machinability of a Stainless Steel by Electrochemical Discharge Microdrilling  

SciTech Connect

Due to the chemical elements included in their structure for ensuring an increased resistance to the environment action, the stainless steels are characterized by a low machinability when classical machining methods are applied. For this reason, sometimes non-traditional machining methods are applied, one of these being the electrochemical discharge machining. To obtain microholes and to evaluate the machinability by electrochemical discharge microdrilling, test pieces of stainless steel were used for experimental research. The electrolyte was an aqueous solution of sodium silicate with different densities. A complete factorial plan was designed to highlight the influence of some input variables on the sizes of the considered machinability indexes (electrode tool wear, material removal rate, depth of the machined hole). By mathematically processing of experimental data, empirical functions were established both for stainless steel and carbon steel. Graphical representations were used to obtain more suggestive vision concerning the influence exerted by the considered input variables on the size of the machinability indexes.

Coteata, Margareta; Pop, Nicolae; Slatineanu, Laurentiu ['Gheorghe Asachi' Technical University of Iasi, Department of Machine Manufacturing Technology, Blvd. D Mangeron 59A, 700050 Iasi (Romania); Schulze, Hans-Peter [Otto-von-Guericke-University Magdeburg, Institute of Fundamental Electrical Engineering and EMC Universitaetsplatz 2, D-39106 Magdeburg (Germany); Besliu, Irina [University 'Stefan cel Mare' of Suceava, Department of Technologies and Management, Str. Universitatii, 13, 720 229 Suceava (Romania)

2011-05-04

195

Stainless-steel elbows formed by spin forging  

NASA Technical Reports Server (NTRS)

Large seamless austenitic stainless steel elbows are fabricated by spin forging /rotary shear forming/. A specially designed spin forging tool for mounting on a hydrospin machine has been built for this purpose.

1964-01-01

196

Correlations between mechanical properties and cavitation erosion resistance for stainless steels with 12% Chromium and variable contents of Nickel  

NASA Astrophysics Data System (ADS)

The running time of hydraulic machineries in cavitation conditions, especially blades and runners, depend on both chemical composition and mechanical properties of the used steels. The researches of the present paper have as goal to obtain new materials with improved behavior and reduced costs. There are given cavitation erosion results upon eight cast steels with martensite as principal structural constituent. The chromium content was maintained constant at approximate 12% but the nickel content was largely modified. The change of chemical content resulted in various proportions of austenite, martensite and ferrite and also in different cavitation erosion behavior. From the eight tested steels four have greater carbon content (approximately 0.1%) and the other four less carbon content (approximate 0.036%). All steels were tested separately in two laboratory facilities: T1 with magnetostrictive nickel tube (vibration amplitude 94 ?m, vibration frequency 7000 3% Hz, specimen diameter 14 mm and generator power 500 W) and T2 is respecting the ASTM G32-2010 Standard (vibration amplitude 50?m, vibration frequency 20000 1% Hz, specimen diameter 15.8 mm and generator power 500 W). Analyzing the results it can be seen that the cavitation erosion is correlated with the mechanical properties in the way shown in 1960 by Hammitt and Garcia but is influenced by the structural constituents.

Bordeasu, I.; Popoviciu, M. O.; Mitelea, I.; Ghiban, B.; Ghiban, N.; Sava, M.; Duma, S. T.; Badarau, R.

2014-03-01

197

INFLUENCE OF RARE EARTH METALS ON PROPERTIES OF Cr-Ni STEEL  

Microsoft Academic Search

Steel (40KhN) was alloyed in a ladle by addition of ferrocerium in ; quantities from 0.1 to 0.8%. After alloying, the steel was normalized, quenched, ; tempered, and tested to determine the effect of the additions and of tempering ; temperature on hardenability, temper brittleness, cold shortness, yield point, ; tensile strength, resilience, plasticity, and grain size. (Rev. Metal Lit.,

Ya. E. Goldshtein; V. I. Zeldovich; A. I. Komissarov; E. L. Korotkevich

1963-01-01

198

Friction and wear properties of thermo-reactive diffusion coatings against titanium nitride coated steels  

Microsoft Academic Search

In this work, the tribological behavior of hardened, tufftrited, titanium nitride coated, boronized, chromium carbide coated and vanadium carbide coated AISI 52100 steel balls against titanium nitride coated AISI 1020 steel disc have been studied under 0.5, 1 and 2 N loads. Titanium nitride, chromium carbide, vanadium carbide coating were performed by pack method. Tufftriting and boronizing treatment were performed

Ugur Sen

2005-01-01

199

Fatigue properties of Ti-based hard coatings deposited onto tool steels  

Microsoft Academic Search

During cold forming processes like deep drawing of steel sheets, tools are subjected to various loads. Besides adhesion, abrasion and tribo-oxidation, successive impacts during forming induce Hertzian contact pressures and cause fatigue failure. The aim of this work is to evaluate different hard coatings deposited by PACVD and magnetron sputtering onto tool steels with respect to adhesion and fatigue. The

M. Stoiber; M. Panzenbck; C. Mitterer; C. Lugmair

2001-01-01

200

Prediction of Mechanical Properties in Submerged Arc Weld Metal of CMn Steel  

Microsoft Academic Search

The prediction model has been developed for steel weld metal mechanical properties as a function of flux ingredients such as CaO, MgO, CaF2 and Al2O3 in submerged arc welding carried out at fixed welding parameters. The results of quantitative measurements of mechanical properties on eighteen weld metal samples were utilized for developing the prediction equations of mechanical properties applying statistical

Prasanta Kanjilal; Tapan Kumar Pal; Sujit Kumar Majumdar

2007-01-01

201

Effect of High Cooling Rates on the Mineralogy and Hydraulic Properties of Stainless Steel Slags  

NASA Astrophysics Data System (ADS)

This article investigates the effect of chemical composition and cooling rate during solidification on the mineralogy and hydraulic properties of synthetic stainless steel slags. Three synthetic slags, covering the range of typical chemical composition in industrial practice, were subjected to high cooling rates, by melt spinning granulation or quenching in water, and to low cooling rates, by cooling inside the furnace. Both methods of rapid cooling led to volumetrically stable slags unlike the slow cooling which resulted in a powder-like material. Stabilized slags consisted predominantly of lamellar ?-dicalcium silicate ( ?-C2S) and Mg, Ca-silicates (merwinite and bredigite); the latter form the matrix at low basicity and are segregated along the C2S grain boundaries at high basicities. Slowly cooled slags consist of the ?-C2S polymorph instead of the ?-C2S and of less Mg, Ca-silicates. Isothermal conduction calorimetry and thermogravimetric analysis indicate the occurrence of hydration reactions in the stabilized slags after mixing with water, while calcium silicate hydrates (C-S-H) of typical acicular morphology are identified by SEM. The present results demonstrate that the application of high cooling rates can result in a stable, environmental-friendly, hydraulic binder from stainless steel slags, rich in ?-C2S, without the necessity of introducing any additions to arrest the ? polymorph.

Kriskova, Lubica; Pontikes, Yiannis; Pandelaers, Lieven; Cizer, zlem; Jones, Peter Tom; Van Balen, Koen; Blanpain, Bart

2013-10-01

202

Mechanical properties of friction stir welded 11Cr-ferritic/martensitic steel  

NASA Astrophysics Data System (ADS)

Friction stir welding was applied to the wrapper tube materials, 11Cr-ferritic/martensitic steel, designed for fast reactors and defect-free welds were successfully produced. The mechanical and microstructural properties of the friction stir welded steel were subsequently investigated. The hardness values of the stir zone were approximately 550 Hv (5.4 GPa) with minimal dependence on the rotational speed, even though they were much higher than those of the base material. However, tensile strengths and elongations of the stir zones were high at 298 K, compared to those of the base material. The excellent tensile properties are attributable to the fine grain formation during friction stir welding.

Yano, Y.; Sato, Y. S.; Sekio, Y.; Ohtsuka, S.; Kaito, T.; Ogawa, R.; Kokawa, H.

2013-11-01

203

Microstructure and mechanical properties of microwave sintered austenitic stainless steel  

Microsoft Academic Search

The objective of this work is focused on understanding the effect of microwave heating on sintering of 316L powders. The stainless\\u000a steel samples were prepared from prealloyed powders of 316L. The powder samples were compacted at a pressure of 560 MPa and\\u000a sintered at 1300C in a microwave furnace of 2.4 GHz and 2KW capacity in nitrogen atmosphere. The sintering

S. Kennedy; S. Kumaran; T. Srinivasa Rao

2011-01-01

204

Effects of Heat Treatment on Microstructure and Tensile Properties of a Fe-27Mn-12Al-0.8C Low-Density Steel  

NASA Astrophysics Data System (ADS)

A low-density duplex steel of Fe-27Mn-12Al-0.8C (density 6.53 g/cm3) was directly quenched to room temperature and ordering treated at 500C and 700C after solution treatment. The heat-treated microstructures and corresponding room-temperature tensile properties were investigated. The ? phase precipitated in austenite in all the cases such that its size became coarser with increasing ordering temperature. Ferrite of the as-quenched steel consisted of the B2 domains and disordered ferrite with uniformly distributed nanosized D03 particles. Ferrite of the 700C ordering steel exhibited basically identical features to the as-quenched steel, but with the coarser B2 domains, finer D03 particles, and less disordered ferrite. By contrast, the D03 domains were mainly observed in ferrite of the 500C ordering steel. The yield strength of the 500C ordering steel was higher than other two steels, which showed the similar yield strengths. The elongation of the as-quenched steel was higher than two ordering-treated steels. Deformation of austenite was manifested by the ? phase shearing by planar gliding dislocations. Intensive interactions of superdislocations were mainly observed in ferrite, depending on the type of the ordered phase. Factors influencing the strength and deformation behavior of the low-density duplex steel were discussed based on observation of deformed microstructure. Overall, the high-Mn/Al duplex steels with the ordered phases exhibit the high specific strength, the low density, and the moderate strain hardening that are suitable for the structural use requiring high strength and light weight.

Park, Kyung-Tae; Hwang, Si Woo; Son, Chang Young; Lee, Jae-Kon

2014-09-01

205

Microstructures and Mechanical Properties of Nano/Ultrafine-Grained N-Bearing, Low-Ni Austenitic Stainless Steels  

NASA Astrophysics Data System (ADS)

The nitrogen (N)-bearing austenitic stainless steels are new materials with interesting mechanical properties such as high strength and ductility, desirable toughness and work hardening, and good corrosion resistance. This work attempted to investigate the effect of N addition from 0.08 to 0.35 wt.% on grain refinement of the 201L austenitic stainless steel using the martensite thermomechanical process. This process was composed of cold rolling up to the thickness reduction of 90 % followed by reversion annealing at 800 C for 60 and 1800 s. It was found that increasing N content resulted in an increase in the austenite grain size for short annealing duration (e.g. 60 s), but caused a decrease in the austenite grain size for long annealing duration (e.g. 1800 s). The smallest austenite grain size of about 150 nm was achieved for the 201L steel containing 0.08 wt.% N after reversion annealing at 800 C for 60 s. The mechanical properties of the reversion-annealed N-bearing steels were enhanced due to both N alloying and grain refinement.

Saeedipour, S.; Kermanpur, A.; Najafizadeh, A.; Abbasi, M.

2014-12-01

206

Localized dispersing of ceramic particles in tool steel surfaces by pulsed laser radiation  

NASA Astrophysics Data System (ADS)

In this paper the capability of a localized laser dispersing technique for changing the material microstructure and the surface topology of steels is discussed. The laser implantation named technique bases on a discontinuous dispersing of ceramic particles into the surface of steels by using pulsed laser radiation. As ceramic particles TiC, WC and TiB2 are used, substrate material is high-alloyed cold working steel (X153CrMoV12). The influence of the laser parameters pulse length and pulse intensity was investigated in a comprehensive parameter study. The gained surface topology and microstructure were evaluated by optical microscopy, energy dispersive X-ray spectroscopy (EDX) and white light interferometry; mechanical properties were analyzed by micro hardness measurement. The experiments reveal that the alignment of separated, elevated, dome-shaped spots on the steel surface is feasible. The geometrical properties as well as the mechanical properties are highly controllable by the laser parameters. The laser implanted spots show a mostly crack-free and pore-free bonding to the substrate material as well as a significant increase of micro hardness.

Hilgenberg, K.; Behler, K.; Steinhoff, K.

2014-06-01

207

The Recovery of Elastic Properties at 35 C in TRIP 700 Steel Following Deformation  

NASA Astrophysics Data System (ADS)

The influence of plastic deformation on the elastic properties that determine the magnitude of springback following forming was investigated using dynamic modulus analysis. For this study, the elastic modulus of TRIP 700 steel was measured continuously at 35 C and a loading frequency of 1.0 Hz for 1000 min following deformation by cold rolling to varying levels up to 27%. The elastic modulus increased at an exponentially decaying rate during these experiments and with a magnitude that increased with pre-strain. These observations are consistent with the hypothesis that deformation creates microstructural defects that contribute compliance when the stress state changes and that these defects are removed by annealing at this low temperature.

Pitchure, D. J.; Ricker, R. E.

2007-06-01

208

Effect of yttrium addition on the microstructure and mechanical properties of ODS RAF steels  

NASA Astrophysics Data System (ADS)

An oxide dispersion strengthened (ODS) alloy with nominal composition Fe-14Cr-2W-0.3Ti-0.24Y (wt.%) was produced by mechanical alloying using elemental powders, and subsequent hot isostatic pressing. The microstructure of the material and characteristics of the oxide particle dispersion were investigated by electron microscopy. The effect of heat treatments on the microhardness and tensile properties at room temperature was also studied. The results show that a fine dispersion of Y-O-rich nanoparticles is achieved, together with larger (Cr, Ti)-rich precipitates. The absence of Ti is apparent in the majority of these nanoparticles, in contrast with reported results for ODS Ti-modified steels processed with Y2O3 addition.

Auger, M. A.; de Castro, V.; Leguey, T.; Tarcsio-Costa, J.; Monge, M. A.; Muoz, A.; Pareja, R.

2014-12-01

209

Sigma phase precipitation and properties of super-duplex stainless steel UNS S32750 aged at the nose temperature  

Microsoft Academic Search

The nose temperature for ?-phase precipitation in super-duplex stainless steel (SDSS) UNS S32750 was evaluated by hardness method. Color-optical microscopy,\\u000a scanning electron microscopy, energy spectrum analysis, impact and corrosion testing were carried out to investigate characteristics\\u000a of microstructure and properties of the SDSS aged at the nose temperature. The experimental results indicate that the nose\\u000a temperature of precipitation is 920

Dening Zou; Ying Han; Wei Zhang; Junhui Yu

2011-01-01

210

TiC precipitation induced effect on microstructure and mechanical properties in low carbon medium manganese steel  

Microsoft Academic Search

The precipitation behavior of titanium treated by different processes and its effect on microstructure and mechanical properties has been investigated in low carbon medium manganese steel. It is found that the formed precipitates during both tempering and reheating-quenching processes are TiCs. The size of them mainly ranges from 1 to 18nm and 1 to 36nm, respectively. And tempering treatment especially

Y. Han; J. Shi; L. Xu; W. Q. Cao; H. Dong

211

Ultrahigh Carbon Steels  

NASA Astrophysics Data System (ADS)

Recent studies and results on ultrahigh carbon (UHC) steels suggest that major development efforts on these steels are timely and that programs to evaluate prototype structural components should be initiated. These recent results include: the development of economical processing techniques incorporating a divorced eutectoid transformation, the improvement of room temperature strength and ductility by heat treatment, the enhancement of superplastic properties through dilute alloying with silicon, and the attainment of exceptional notch impact strength in laminated UHC steel composites manufactured through solid state bonding. The unique mechanical properties achieved in UHC steels are due to the presence of micron-size fer-rite grains and ultrafine spheroidized carbides.

Sherby, O. D.; Oyama, T.; Kum, D. W.; Walser, B.; Wadsworth, J.

1985-06-01

212

Effect of large plastic deformation on microstructure and mechanical properties of a TWIP steel  

NASA Astrophysics Data System (ADS)

The effect of cold rolling on the microstructure evolution and mechanical properties of a cold rolled Fe-0.3C-17Mn-1.5AI TWIP steel was studied. The plate samples were cold rolled with reductions of 20, 40, 60 and 80%. The structural changes were associated with the development of deformation twinning and shear bands. The average spacing between twin boundaries in the transverse section of the rolled plates decreased from ~190 to 36 nm with an increase in the rolling reduction from 20 to 40%. Upon further rolling to 80% reduction the twin spacing remained at about 30 nm. The cold rolling resulted in significant increase in strength as revealed by tensile tests at an ambient temperature. The offset yield stress approached 1440 MPa, and the ultimate tensile strength increased to 1630 MPa after rolling reduction of 80%. Such significant strengthening was attributed to the development of specific structure consisting of deformation nanotwins with high dislocation density.

Yanushkevich, Z.; Belyakov, A.; Kaibyshev, R.; Molodov, D.

2014-08-01

213

Tensile and transient burst properties of advanced ferritic/martensitic steel claddings after neutron irradiation  

NASA Astrophysics Data System (ADS)

The effects of fast neutron irradiation on tensile and transient burst properties of advanced ferritic/martensitic steel claddings for fast breeder reactors were investigated. Specimens were irradiated in the experimental fast reactor JOYO using the material irradiation rig at temperatures between 773 and 1013 K to fast neutron doses ranging from 11 to 102 dpa. The post-irradiation tensile and temperature-transient-to-burst tests were carried out. The results of mechanical tests showed that there was no significant degradation in tensile and transient burst strengths after neutron irradiation below 873 K. This was attributed to grain boundary strengthening caused by precipitates that preferentially formed on prior-austenite grain boundaries. Both strengths at neutron irradiation above about 903 K up to 102 dpa decreased due to radiation enhanced recovery of lath martensite structures and recrystallization.

Yano, Y.; Yoshitake, T.; Yamashita, S.; Akasaka, N.; Onose, S.; Takahashi, H.

2007-08-01

214

Influence of explosive density on mechanical properties of high manganese steel explosion hardened  

NASA Astrophysics Data System (ADS)

The explosion hardening tests of high manganese steel were carried out by using two kinds of explosives of the same composition but different density, respectively. The detonation velocities were tested and the relevant mechanical properties were studied. The results show that the stronger single impulse acting on the specimen, the more hardness of surface increases and the more impact toughness decreases. Compared with the explosive of 1.48 g/cm3 density, the hardness, elongation rate, and impact toughness of the sample for triple explosion with explosive of 1.38 g/cm3 density are larger at the same hardening depth. In addition, the tensile strength of the sample for triple explosion with density of 1.38 g/cm3 is higher from the surface to 15 mm below the surface hardened.

Hu, Xiaoyan; Shen, Zhaowu; Liu, Yingbin; Liu, Tiansheng; Wang, Fengying

2013-12-01

215

Air cooled bainitic steels for strong, seamless Part 2 properties and microstructure of  

E-print Network

Air cooled bainitic steels for strong, seamless pipes Part 2 ­ properties and microstructure for the manufacture of seamless pipes. The alloys were intended to develop into mixtures of bainitic ferrite and toughness have been achieved. Keywords: Seamless pipe, Hot rolled, Bainite, Retained austenite Introduction

Cambridge, University of

216

Effect of grain size and low-temperature duration on the properties of tool steel  

Microsoft Academic Search

In spite of the large amount of work devoted to the properties of carbon tool steels and their connection with the operating reliability of articles, some questions still remain open. First of all, it is necessary to turn attention to the effect of brittle strength on the endurance of articles which are often used after treatment for high hardness (reamers,

B. S. Natapov

1991-01-01

217

Effect of electron-beam melting and heat treatment on the structure, composition, and properties of tool steels  

SciTech Connect

A method was developed for the surface-melting and quench-hardening of tool steels through the use of electron-beam heating. The structural transformations, composition, and properties of die steels 5KhNM, 4Kh5MFS, and DI23, and ball-bearing steel ShKh15SG were studied after surface electron beam melting. Methods were also investigated for improving the structure and properties of the steels through heat treatment. The distribution of alloying elements in treatment zones was studied.

Veinik, A.I.; Pobol', I.L.; Shipko, A.A.

1988-07-01

218

Improvement of resistance to oxidation by laser alloying on a tool steel  

SciTech Connect

The goal of this work is to improve the resistance to oxidation at high temperature of a tool steel (D2) without degrading its satisfactory tribologic properties. In a recent paper, the authors showed that the combination in the same coating, of chromium and silicon can provide increased resistance to oxidation at high temperature, a combination which until then had been used only in massive alloys. The present investigation deals with a steel initially having 12% chromium. The addition of silicon to the steel surface should improve the resistance to oxidation to the minimum levels required by the steel high operating temperatures. On the other hand, it has also been shown that the chromium and carbon addition leads to the formation o hard phases [(Fe,Cr){sub 7}C{sub 3}] necessary for a good anti-wear behavior. The increase of the chromium concentration in solid solution and the presence of carbide in the coating, obtained by the addition of Cr{sub 3}C{sub 2}, should then increase not only the resistance to oxidation, but also the resistance to wear. The possibility of obtaining the same effects by the addition o silicon carbide or chromium carbide to the D2 steel surface has also been investigated.

Gemellli, E.; Gallerie, A.; Caillet, M.

1998-10-13

219

A mechanical property and stress corrosion evaluation of Custom 455 stainless steel alloy  

NASA Technical Reports Server (NTRS)

The mechanical and stress corrosion properties are presented of vacuum melted Custom 455 stainless steel alloy bar (1.0-inch diameter) and sheet (0.083-inch thick) material aged at 950 F, 1000 F, and 1050 F. Low temperature mechanical properties were determined at temperatures of 80 F, 0 F, -100 F, and -200 F. For all three aging treatments, the ultimate tensile and 0.2 percent offset yield strengths increased with decreasing test temperatures while the elongation held fairly constant down to -100 F and decreased at -200 F. Reduction in Area decreased moderately with decreasing temperature for the longitudinal round (0.250-inch diameter) specimens. Notched tensile strength and charpy V-notched impact strength decreased with decreasing test temperature. For all three aging treatments, no failures were observed in the unstressed specimens or the specimens stressed to 50, 75, and 100 percent of their yield strengths for 180 days of alternate immersion testing in a 3.5 percent NaCl solution. As indicated by the results of tensile tests performed after alternate immersion testing, the mechanical properties of Custom 455 alloy were not affected by stress or exposure under the conditions of the evaluation.

Montano, J. W.

1972-01-01

220

Microstructure, Texture, and Mechanical Property Analysis of Gas Metal Arc Welded AISI 304 Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

The present study elaborately explains the effect of welding parameters on the microstructure, texture, and mechanical properties of gas metal arc welded AISI 304 austenitic stainless steel sheet (as received) of 4 mm thickness. The welded joints were prepared by varying welding speed (WS) and current simultaneously at a fixed heat input level using a 1.2-mm-diameter austenitic filler metal (AISI 316L). The overall purpose of this study is to investigate the effect of the variation of welding conditions on: (i) Microstructural constituents using optical microscope and transmission electron microscope; (ii) Micro-texture evolution, misorientation distributions, and grain boundaries at welded regions by measuring the orientation data from electron back scattered diffraction; and (iii) Mechanical properties such as hardness and tensile strength, and their correlation with the microstructure and texture. It has been observed that the higher WS along with the higher welding current (weld metal W1) can enhance weld metal mechanical properties through alternation in microstructure and texture of the weld metal. Higher ?-ferrite formation and high-angle boundaries along with the <101> + <001> grain growth direction of the weld metal W1 were responsible for dislocation pile-ups, SFs, deformation twinning, and the induced martensite with consequent strain hardening during tensile deformation. Also, fusion boundary being the weakest link in the welded structure, failure took place mainly at this region.

Saha, Saptarshi; Mukherjee, Manidipto; Pal, Tapan Kumar

2014-12-01

221

A new high nitrogen super austenitic stainless steel with improved structure stability and corrosion resistance properties  

SciTech Connect

A new highly alloyed (Cr, Mo, W, N) super austenitic grade has been developed. This grade offers high mechanical properties combined with excellent corrosion resistance in chloride acid media. This grade is particularly designed for applications in chloride, oxidizing acid media encountered in the chemical, transportation, pollution control, offshore and pulp and paper industries. Mechanical properties, corrosion resistance and weldability of this grade are presented and compared to that of other stainless steels and nickel base alloys.

Gagnepain, J.C.; Charles, J.; Coudreuse, L.; Bonnefois, B. [Creusot-Loire Industrie, Le Creusot (France)

1996-11-01

222

Nondestructive determination of tensile properties and fracture toughness of cold worked A36 steel  

Microsoft Academic Search

Tensile and fracture properties of ASTM grade A36 steel have been studied using nondestructive StressStrain Microprobe system (SSM), which is developed on the basis of automated ball indentation (ABI) technique. Tests have been carried out on as-received, and cold worked (4, 8 and 12%) materials at several temperatures in the range ?150C+200C at a constant strain rate. Tensile properties determined

K. L. Murty; M. D. Mathew; Y. Wang; V. N. Shah; F. M. Haggag

1998-01-01

223

Effects of alloying elements on the mechanical properties and corrosion behaviors of 2205 duplex stainless steels  

NASA Astrophysics Data System (ADS)

The effects of alloying elements on the microstructure, mechanical properties, and corrosion behaviors of duplex stainless steels (DSSs) have been investigated in this study. Experimental alloys were prepared by varying the concentrations of the constituent elements in DSSs. Hot ductility test, tensile test, charpy impact test, and corrosion test were performed to evaluate the properties of the experimental alloys. The results showed that the extent of edge cracking of DSSs increased with the increasing value of the crack sensitivity index (CSI). The higher the hot ductility index (HDI) was, the better the hot ductility of DSSs achieved. Austenite ( ?) stabilizer generally caused a decrease in the strength and an increase in the charpy impact absorbed energy of the stainless steel. On the contrary, ferrite ( ?) former exerted its beneficial effect on the strength but became detrimental to the toughness of DSSs. The presences of sulfur and boron also caused a decrease in the impact energy, but nitrogen and carbon hardly affected the toughness within the concentration range tested in this study. The value of pitting nucleation potential ( E np ) of different nitrogen contents in 3.5 wt.% NaCl solution at room temperature was almost the same, but the value of pitting protection potential ( E pp ) among these alloys was increased with increasing the content of nitrogen. The susceptibility to stress corrosion cracking (SCC) of DSSs was high when tested in boiling 45 wt.% MgCl2 solution. On the other hand, the time to failure of the experimental steels in 40 wt.% CaCl2 solution at 100 C was longer than that in MgCl2 solution. Nitrogen could affect the SCC behavior of DSSs in CaCl2 solution through the combinative effects by varying the pitting resistance and the slip step dissolution. An optimum nitrogen (N) content of 0.15 wt.% was found where the highest SCC resistance could be obtained. Although ? phase exhibited better resistance to SCC, cracks were found to penetrate through ? and ? grains or to propagate along the ?/? interface. As a result, a mixed transgranular plus intergranular mode of fracture surface was observed.

Liou, Horng-Yih; Tsai, Wen-Ta; Pan, Yeong-Tsuen; Hsieh, Rong-Iuan

2001-04-01

224

The corrosion inhibition of austenitic chromiumnickel steel in H 2SO 4 by 2-butyn-1-ol  

Microsoft Academic Search

The corrosion inhibition on the austenitic chromiumnickel steel by 2-butyn-1-ol, which is an acetylenic alcohol, has been investigated in sulfuric acid. Therefore, the effect of concentration and temperature on inhibition properties was determined. It was found that this compound is adsorbed on the steel surface. ?-electrons act an important role for this adsorption. The experimental results are in accordance with

S. Bilgi; M. ?ahin

2001-01-01

225

Effects of mechanical alloying time on microstructure and properties of 9Cr-ODS steels  

NASA Astrophysics Data System (ADS)

Pre-alloyed powders of oxide dispersion strengthened (ODS) steels were produced by atomization. The atomized powders without mechanical alloying (MA) and with short-time MA were consolidated by hot isostatic pressing (HIP). The morphology and microstructure of the atomized and the MA powders were studied by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The microstructure of 9Cr-ODS steels with different MA time was characterized by high-resolution transmission electron microscopy (HRTEM), electron backscatter diffraction (EBSD) and atom probe tomography (APT). The results showed that high-density of nanosized precipitates and ultrafine grains are formed in the ODS steels using the processing route, which remarkably reduce MA time. The yield strength and ultimate tensile strength of ODS steels are improved with the increase of MA time.

Xie, Rui; Lu, Zheng; Lu, Chenyang; Liu, Chunming

2014-12-01

226

Mechanical properties and fatigue crack growth rate of laser-welded 4130 steel  

NASA Astrophysics Data System (ADS)

The effect of the type of the postweld heat treatment (PWHT) on the mechanical and fatigue properties of AISI 4130 laser-welded steel were investigated using results of tensile, impact, and fatigue-crack-growth tests and SEM observations. The results show that necking of a tensile specimen is concentrated in the overtempered zone, resulting in an overall reduction in elongation of the weld. It was found that a 1-hr PWHT at 525 C or a laser multiple-tempering process can greatly improve the impact toughness of laser-welded steel.

Tsay, L. W.; Li, Y. M.; Chen, C.; Cheng, S. W.

1992-07-01

227

GASEOUS HYDROGEN EFFECTS ON THE MECHANICAL PROPERTIES OF CARBON AND LOW ALLOY STEELS (U)  

SciTech Connect

This report is a compendium of sets of mechanical properties of carbon and low alloy steels following the short-term effects of hydrogen exposure. The property sets include the following: Yield Strength; Ultimate Tensile Strength; Uniform Elongation; Reduction of Area; Threshold Cracking, K{sub H} or K{sub th}; Fracture Toughness (K{sub IC}, J{sub IC}, and/or J-R Curve); and Fatigue Crack Growth (da/dN). These properties are drawn from literature sources under a variety of test methods and conditions. However, the collection of literature data is by no means complete, but the diversity of data and dependency of results in test method is sufficient to warrant a design and implementation of a thorough test program. The program would be needed to enable a defensible demonstration of structural integrity of a pressurized hydrogen system. It is essential that the environmental variables be well-defined (e.g., the applicable hydrogen gas pressure range and the test strain rate) and the specimen preparation be realistically consistent (such as the techniques to charge hydrogen and to maintain the hydrogen concentration in the specimens).

Lam, P

2006-06-08

228

Predictions of the Mechanical Properties and Microstructure Evolution of High Strength Steel in Hot Stamping  

NASA Astrophysics Data System (ADS)

Hot stamping is an innovative operation in metal-forming processes which virtually avoids the cracking and wrinkling of high strength steel (HSS) sheets. Examining the phase transformation and mechanical properties of HSS by means of experiments is challenging. In this article, a numerical model of the hot stamping process including forming, quenching, and air cooling was developed to reveal the microstructure evolution and to predict the final mechanical properties of hot-stamped components after multi-process cycles. The effects of the number of process cycles and the holding times on the temperature of HSS were examined using the model. The microstructure evolution of HSS under variable holding times is illustrated. The mechanical properties, particularly hardness and tensile strength, were predicted. It was found that the martensitic content increased with increasing holding time, and the martensitic content of the formed component at the flange and end was higher than for the sidewall, and lowest for the bottom. The hardness trend was consistent with the martensitic content. After six process cycles, the predictive errors of the model for hardness and tensile strength were acceptable for practical applications in engineering. Comparison between the predicted results and the experiment results showed that the developed model was reliable.

Cui, Junjia; Lei, Chengxi; Xing, Zhongwen; Li, Chunfeng; Ma, Shumei

2012-11-01

229

Effect of Vanadium Nitride Precipitation on Martensitic Transformation and Mechanical Properties of CrMnNi Cast Austenitic Steels  

NASA Astrophysics Data System (ADS)

The microstructural evolution and mechanical properties of two cast Fe-15Cr-6Mn-3Ni-0.5Si-0.2N-0.1C (concentrations in wt pct) steels containing no vanadium and 0.65 wt pct vanadium were investigated under uniaxial tensile loading for room temperature (RT) and 373 K (100 C). The alloy development was focused on the formation of nanosized vanadium nitride precipitates in the austenite to serve as obstacles to dislocation motion. The austenitic steels exhibited transformation- and twinning-induced plasticity (TRIP/TWIP) effects and the planar glide of dislocations in the austenite. The triggering stress for the RT strain-induced ? ???' formation increased by 190 MPa, and the transformation occurred at higher strain levels due to the presence of VN precipitates. The occurrence of the TWIP effect during tensile testing at 373 K (100 C) of both steels resulted in engineering strains above 50 pct. The yield strength (YS) of the VN-containing steel was 420 MPa at RT, 52 MPa higher than the vanadium-free alloy. The difference increased to 59 MPa at 373 K (100 C) with the VN-containing alloy exhibiting a YS of 311 MPa.

Wendler, Marco; Reichel, Benedikt; Eckner, Ralf; Fabrichnaya, Olga; Krger, Lutz; Wei, Andreas; Mola, Javad

2014-12-01

230

Metal-induced embrittlement of low-carbon steel by indium in association with tellurium  

SciTech Connect

Liquid metal embrittlement is harmful to mechanical properties such as ductility and toughness, and thus, should be prevented. However, there is one case for which liquid metal embrittlement is useful: it is believed to be at least one of the machinability improvement mechanisms by Pb and Bi in steel and Al alloys. It is known that tellurium compounds, such as PbTe and the MnTe-MnS eutectic, also cause liquid metal embrittlement around their melting temperatures of 923 C and 810 C, respectively. However, their melting points are believed to be too high for machinability improvement. The typical temperature range in the shear zones during conventional machining of low carbon steels is believed to be between 150 and 800 C. The In-Te binary phase diagram suggests that several intermetallic compounds could be formed. Thus, if any of these compounds are formed in steel, different machinability behavior could be expected. However, no thermodynamic data are available to indicate whether or not these intermetallic compounds can form in solid steel. Thus, this investigation was initiated to study (1) whether or not tellurium and indium form intermetallic compounds in steel and (2) if so, how these compounds affect liquid metal embrittlement behavior.

Yaguchi, Hiroshi (Kobe Steel, Ltd., Hyogo (Japan))

1993-02-01

231

Evaluation of fatigue properties of 316FR stainless steel welded joints at elevated temperature  

SciTech Connect

316FR is an improved version of type 316 stainless steel for elevated temperature use with lower carbon content than conventional type 316 stainless steel. Fatigue properties of GTAW joints of 316FR stainless steel have been investigated. Heat affected zone (HAZ) of 316FR becomes harder than base metal. A method based on the stress-strain relationship of three elements, which are base metal, HAZ and weld portions, has been proposed and applied to the evaluations of fatigue tests. The tri-metal analysis model gives good agreements between experimental results and predicted fatigue lives of the 316FR welded joints. This material is to be used in the DFBR reactor in Japan.

Kaguchi, Hitoshi; Koto, Hiroyuki [Mitsubishi Heavy Industries, Ltd., Kobe (Japan); Fujioka, Terutaka [Japan Atomic Power Co., Tokyo (Japan); Taguchi, Kosei [Toshiba Corp., Yokohama (Japan); Sukekawa, Masayuki [Hitachi Ltd. (Japan)

1996-12-01

232

Study on the mechanical properties evolution of A508-3 steel under proton irradiation  

NASA Astrophysics Data System (ADS)

In an effort to study the effect of irradiation on the hardening behavior of reactor pressure vessel (RPV) steel, nanoindentation was employed to investigate the mechanical properties of A508-3 steel after an irradiation with 190 keV proton to the dose range of 0.054-0.271 displacement per atom (dpa) at room temperature. The results show that the relationship between the nanohardness and indent depth is in accordance with the Nix-Gao model. The nanohardness of A508-3 steel increases notably with the dose. In addition, the contribution of the irradiation-induced microstructural defects including matrix damage and nano clusters to the irradiation hardening is discussed.

Lei, Jing; Ding, Hui; Shu, Guo-gang; Wan, Qiang-mao

2014-11-01

233

Creep Rupture Properties of Welded Joints of Heat Resistant Steels  

NASA Astrophysics Data System (ADS)

In this study, the high-temperature mechanical and creep rupture properties of Grade 91/Grade 91 (Mod. 9Cr-Mo) similar welded joints and Grade 91/Inconel 82/SUS304 dissimilar welded joints were examined. The effects of temperature and stress on the failure location in the joints were also investigated. Creep rupture tests were conducted at 823, 873, and 923 K; the applied stress ranges were 160-240, 80-160, and 40-80 MPa, respectively. The creep rupture strengths of the specimens with welded joints were lower than those of the specimens of the base metal at all temperature levels; in addition, these differences in creep strength increased with temperature. After being subjected to long-term creep rupture tests, the fracture type exhibited by the dissimilar welded joints was transformed from Types V and VII to Type IV. It was estimated that the fracture type exhibited by the dissimilar welded joints after 100,000-h rupture strength tests at 823 K and 873 K was Type IV fracture.

Yamazaki, Masayoshi; Watanabe, Takashi; Hongo, Hiromichi; Tabuchi, Masaaki

234

Mechanical properties of thermally aged cast stainless steels from Shippingport reactor components  

SciTech Connect

Thermal embrittlement of static-cast CF-8 stainless steel components from the decommissioned Shippingport reactor has been characterized. Cast stainless steel materials were obtained from four cold-leg check valves, three hot-leg main shutoff valves, and two pump volutes. The actual time-at-temperature for the materials was {approximately}13 y at {approximately}281 C (538 F) for the hot-leg components and {approximately}264 C (507 F) for the cold-leg components. Baseline mechanical properties for as-cast material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 C and then water quenched, or material from the cooler region of the component. The Shippingport materials show modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength because of relatively low service temperatures and ferrite content of the steel. The procedure and correlations developed at Argonne National Laboratory for estimating mechanical properties of cast stainless steels predict accurate or slightly lower values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predicted the mechanical properties of the Ringhals 2 reactor hot and crossover-leg elbows (CF-8M steel) after service of {approximately} 15 y and the KRB reactor pump cover plate (CF-8) after {approximately} 8 y of service.

Chopra, O.K.; Shack, W.J. [Argonne National Lab., IL (United States)

1995-04-01

235

Mechanical properties of thermally aged cast stainless steels from shippingport reactor components.  

SciTech Connect

Thermal embrittlement of static-cast CF-8 stainless steel components from the decommissioned Shippingport reactor has been characterized. Cast stainless steel materials were obtained from four cold-leg check valves, three hot-leg main shutoff valves, and two pump volutes. The actual time-at-temperature for the materials was {approx}13 y at {approx}281 C (538 F) for the hot-leg components and {approx}264 C (507 F) for the cold-leg components. Baseline mechanical properties for as-cast material were determined from tests on either recovery-annealed material, i.e., annealed for 1 h at 550 C and then water quenched, or material from the cooler region of the component. The Shippingport materials show modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength because of relatively low service temperatures and ferrite content of the steel. The procedure and correlations developed at Argonne National Laboratory for estimating mechanical properties of cast stainless steels predict accurate or slightly lower values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and JIC of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predicted the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y and the KRB reactor pump cover plate (CF-8) after {approx}8 y of service.

Chopra, O. K.; Shack, W. J.; Energy Technology

1995-06-07

236

Fatigue Properties and Fracture Mechanism of Steel Coated with Diamond-Like Carbon Films  

NASA Astrophysics Data System (ADS)

Diamond-like carbon (DLC) films have attracted much attention in many industrial fields because of their excellent tribological properties, high hardness, chemical inertness and biocompatibility. In order to examine the fatigue properties and to clear the fracture mechanism of DLC coated materials, AISI4140 steel coated with DLC films by using unbalanced magnetron sputtering method was prepared and two types of fatigue test were carried out by using a tension and compression testing machine with stress ratio -1 and a bending testing machine with stress ratio -1 with a focused on the fatigue crack behavior in detail. The fracture origin changed from the slip deformation to micro defects at surface whose size didn't affect the fatigue crack initiation behavior in the case of Virgin series because the hard coating like DLC films make the defect sensitivity of coated material higher. However, DLC series indicated higher fatigue strengths in finite life region and fatigue limit compared with Virgin series. From the continuously observation by using a plastic replicas technique, it is clear that there are no noticeable differences on fatigue crack propagation rate between the Virgin and DLC series, however the fatigue crack initiation of DLC series was delayed significantly by existence of DLC films compared with Virgin series.

Akebono, Hiroyuki; Kato, Masahiko; Sugeta, Atsushi

237

Effects of Mn Addition on Tensile and Charpy Impact Properties in Austenitic Fe-Mn-C-Al-Based Steels for Cryogenic Applications  

NASA Astrophysics Data System (ADS)

Effects of Mn addition (17, 19, and 22 wt pct) on tensile and Charpy impact properties in three austenitic Fe-Mn-C-Al-based steels were investigated at room and cryogenic temperatures in relation with deformation mechanisms. Tensile strength and elongation were not varied much with Mn content at room temperature, but abruptly decreased with decreasing Mn content at 77 K (-196 C). Charpy impact energies at 273 K (0 C) were higher than 200 J in the three steels, but rapidly dropped to 44 J at 77 K (-196 C) in the 17Mn steel, while they were higher than 120 J in the 19Mn and 22Mn steels. Although the cryogenic-temperature stacking fault energies (SFEs) were lower by 30 to 50 pct than the room-temperature SFEs, the SFE of the 22Mn steel was situated in the TWinning-induced plasticity regime. In the 17Mn and 19Mn steels, however, ?'-martensites were formed by the TRansformation-induced plasticity mechanism because of the low SFEs. EBSD analyses along with interrupted tensile tests at cryogenic temperature showed that the austenite was sufficiently deformed in the 19Mn steel even after the formation of ?'-martensite, thereby leading to the high impact energy over 120 J.

Lee, Junghoon; Sohn, Seok Su; Hong, Seokmin; Suh, Byeong-Chan; Kim, Sung-Kyu; Lee, Byeong-Joo; Kim, Nack J.; Lee, Sunghak

2014-11-01

238

Influence of the PM-Processing Route and Nitrogen Content on the Properties of Ni-Free Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

Ni-free austenitic steels alloyed with Cr and Mn are an alternative to conventional Ni-containing steels. Nitrogen alloying of these steel grades is beneficial for several reasons such as increased strength and corrosion resistance. Low solubility in liquid and ?-ferrite restricts the maximal N-content that can be achieved via conventional metallurgy. Higher contents can be alloyed by powder-metallurgical (PM) production via gas-solid interaction. The performance of sintered parts is determined by appropriate sintering parameters. Three major PM-processing routes, hot isostatic pressing, supersolidus liquid phase sintering (SLPS), and solid-state sintering, were performed to study the influence of PM-processing route and N-content on densification, fracture, and mechanical properties. Sintering routes are designed with the assistance of thermodynamic calculations, differential thermal analysis, and residual gas analysis. Fracture surfaces were studied by X-ray photoelectron spectroscopy, secondary electron microscopy, and energy dispersive X-ray spectroscopy. Tensile tests and X-ray diffraction were performed to study mechanical properties and austenite stability. This study demonstrates that SLPS process reaches high densification of the high-Mn-containing powder material while the desired N-contents were successfully alloyed via gas-solid interaction. Produced specimens show tensile strengths >1000 MPa combined with strain to fracture of 60 pct and thus overcome the other tested production routes as well as conventional stainless austenitic or martensitic grades.

Lefor, Kathrin; Walter, M.; Weddeling, A.; Hryha, E.; Huth, S.; Weber, S.; Nyborg, L.; Theisen, W.

2015-03-01

239

Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components  

SciTech Connect

The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950's are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials and irradiation conditions has been produced for reactor tank structural analyses and to quantify the effects of radiation-induced materials degradation for evaluating reactor service life. The data has been collected from the SRL Reactor Materials Program (RMP) irradiations and testing of archival stainless steel weldment components and from previous SRL programs to measure properties of irradiated reactor Thermal Shield weldments and reactor tank (R-tank) sidewall material. Irradiation programs of the RMP are designed to quantify mechanical properties at tank operating temperatures following irradiation to present and future tank wall maximum exposure conditions. The exposure conditions are characterized in terms of fast neutron fluence (E{sub n} > 0.1 MeV) and displacements per atom (dpa){sup 3}. Tensile properties, Charpy-V notch toughness, and elastic-plastic fracture toughness were measured for base, weld, and weld heat-affected zone (HAZ) weldment components from archival piping specimens following a Screening Irradiation in the University of Buffalo Reactor (UBR) and following a Full-Term Irradiation in the High Flux Isotope Reactor (HFIR).

Sindelar, R.L.; Caskey, G.R. Jr.

1991-12-01

240

Reactor Materials Program: Mechanical properties of irradiated Types 304 and 304L stainless steel weldment components  

SciTech Connect

The vessels (reactor tanks) of the Savannah River Site nuclear production reactors constructed in the 1950`s are comprised of Type 304 stainless steel with Type 308 stainless steel weld filler. Irradiation exposure to the reactor tank sidewalls through reactor operation has caused a change in the mechanical properties of these materials. A database of as-irradiated mechanical properties for site-specific materials and irradiation conditions has been produced for reactor tank structural analyses and to quantify the effects of radiation-induced materials degradation for evaluating reactor service life. The data has been collected from the SRL Reactor Materials Program (RMP) irradiations and testing of archival stainless steel weldment components and from previous SRL programs to measure properties of irradiated reactor Thermal Shield weldments and reactor tank (R-tank) sidewall material. Irradiation programs of the RMP are designed to quantify mechanical properties at tank operating temperatures following irradiation to present and future tank wall maximum exposure conditions. The exposure conditions are characterized in terms of fast neutron fluence (E{sub n} > 0.1 MeV) and displacements per atom (dpa){sup 3}. Tensile properties, Charpy-V notch toughness, and elastic-plastic fracture toughness were measured for base, weld, and weld heat-affected zone (HAZ) weldment components from archival piping specimens following a Screening Irradiation in the University of Buffalo Reactor (UBR) and following a Full-Term Irradiation in the High Flux Isotope Reactor (HFIR).

Sindelar, R.L.; Caskey, G.R. Jr.

1991-12-01

241

Effects of hydrogen on the plastic properties of medium-Carbon steels  

Microsoft Academic Search

The effect of hydrogen on the plastic deformation of pearlitic and spheroidized 1045 steels is examined. We find that hyrogen\\u000a in the dissolved state invariably hardens 1045 steel. Luders band formation and propagation require greater applied stress,\\u000a the slope of the stress-strain curve is increased, and the amount of plastic deformation over a given stress-time history\\u000a is decreased by dissolved

R. A. Oriani; P. H. Josephic

1980-01-01

242

The Effect of Cooling Rate, and Cool Deformation Through Strain-Induced Transformation, on Microstructural Evolution and Mechanical Properties of Microalloyed Steels  

NASA Astrophysics Data System (ADS)

In this article, a detailed study was conducted to evaluate the microstructural evolution and mechanical properties of microalloyed steels processed by thermomechanical schedules incorporating cool deformation. Cool deformation was incorporated into a full scale simulation of hot rolling, and the effect of prior austenite conditioning on the cool deformability of microalloyed steels was investigated. As well, the effect of varying cooling rate, from the end of the finishing stage to the cool deformation temperature, 673 K (400 C), on mechanical properties and microstructural evolution was studied. Transmission electron microscopy (TEM) analysis, in particular for Nb containing steels, was also conducted for the precipitation evaluation. Results show that cool deformation greatly improves the strength of microalloyed steels. Of the several mechanisms identified, such as work hardening, precipitation, grain refinement, and strain-induced transformation (SIT) of retained austenite, SIT was proposed, for the first time in microalloyed steels, to be a significant factor for strengthening due to the deformation in ferrite. Results also show that the effect of precipitation in ferrite for the Nb bearing steels is greatly overshadowed by SIT at room temperature.

Mousavi Anijdan, S. H.; Yue, Steve

2012-04-01

243

Fast parallel computation algorithm in application to simulation of semi-solid steel rolling and inverse analysis of its properties  

NASA Astrophysics Data System (ADS)

The contribution deals with the problem of development of a fast computation system allowing for correct interpretation of results of experiments concerning mechanical properties of semi-solid steel. Accurate computer simulation of steel deformation at very high temperature requires information about plastic properties of the material. One of the most important properties of steel subjected to deformation is the stress-strain relationship - yield stress curve. Unlike low temperature tests, deformation of steel samples in temperatures over 1400C causes strain, stress and temperature fields that are strongly inhomogeneous from the physical point of view. Correct interpretation of such experimental results requires inverse analysis based on numerical models providing accurate and fast computation. Similar requirements apply to simulation of the integrated casting and rolling process of semi-solid steel in a sequence of passes. This problem is the main subject of the current paper. Some globally unique example results of the analysis are presented, as well.

G?owacki, Miros?aw; Debi?ski, Tomasz; Olejarczyk-Wo?e?ska, Izabela

2013-10-01

244

1D subsurface electromagnetic fields excited by energized steel casing  

E-print Network

1D subsurface electromagnetic fields excited by energized steel casing Wei Yang1 , Carlos Torres connected to a current source of variable fre- quency. Electromagnetic EM fields excited by the ener- gized, 1990; Kaufman and Wightman, 1993 , electromagnetic EM borehole measurements acquired in the presence

Torres-Verdín, Carlos

245

Effects of alloying elements on mechanical and fracture properties of base metals and simulated heat-affected zones of SA 508 steels  

NASA Astrophysics Data System (ADS)

This study was aimed at developing low-alloy steels for nuclear reactor pressure vessels by investigating the effects of alloying elements on mechanical and fracture properties of base metals and heat-affected zones (HAZs). Four steels whose compositions were variations of the composition specification for SA 508 steel (class 3) were fabricated by vacuum-induction melting and heat treatment, and their tensile properties and Charpy impact toughness were evaluated. Microstructural analyses indicated that coarse M3C-type carbides and fine M2C-type carbides were precipitated along lath boundaries and inside laths, respectively. In the steels having decreased carbon content and increased molybdenum content, the amount of fine M2C carbides was greatly increased, while that of coarse M3C carbides was decreased, thereby leading to the improvement of tensile properties and impact toughness. Their simulated HAZs also had sufficient impact toughness after postweld heat treatment (PWHT). These findings suggested that the low-alloy steels with high strength and toughness could be processed by decreasing carbon and manganese contents and by increasing molybdenum content.

Kim, Sangho; Lee, Sunghak; Im, Young-Roc; Lee, Hu-Chul; Oh, Yong Jun; Hong, Jun Hwa

2001-04-01

246

Mechanical properties and structure of YO dispersion-stabilized, rapidly solidified 316 type stainless steel  

Microsoft Academic Search

An oxide dispersion stabilized 316 stainless steel has been prepared by mechanical alloying of a few 100 A size yttria powders with attrited flakes of 316 stainless steel prealloyed with 1 wt % aluminum. Alloys with 4 vol % and 5 vol % yttria additions have been prepared and they show significant improvements in microstructural stability. Austenitic stainless steel containing

A. I. Ibrahim; J. Megusar; N. J. Grant

1981-01-01

247

CONSUMABLES FOR WELDING OF (VERY) HIGH STRENGTH STEELS - MECHANICAL PROPERTIES OF WELDMENTS IN AS-WELDED AND STRESS RELIEVED APPLICATIONS  

Microsoft Academic Search

The use of (very) high strength steels for the design of high performance steel structures is highly promising as they can allow for substantial savings due to the thickness reduction of structural parts. The application of these steels for structural design, however, is not yet fully developed as limitations are imposed by design codes currently in effect. In addition, when

E. Baun; C. Chovet; B. Leduey; C. Bonnet

248

Influence of high pressure hydrogen environment on tensile and fatigue properties of stainless steels at low temperatures  

NASA Astrophysics Data System (ADS)

Hydrogen environment embrittlement (HEE) of stainless steels in the environment of high pressure and low temperature hydrogen gas was evaluated using a very simple mechanical properties testing procedure. In the method, the high-pressure hydrogen environment is produced just inside the hole in the specimen. In this work, the effects of HEE on fatigue properties for austenitic stainless steels SUS304L and SUS316L were evaluated at 298 and 190 K. The effects of HEE on the tensile properties of higher strength stainless steels, such as strain-hardened 316, SUS630, and other alloys, SUH660 and Alloy 718 were also examined. The less effect of HEE on fatigue properties of SUS316L and tensile properties of strain-hardened 316 were observed compared with SUS304L and other steels at room temperature and 190 K.

Ogata, T.

2012-06-01

249

Influence of the plastic-deformation temperature on the structure and properties of low-carbon pipe steel  

Microsoft Academic Search

21 Controlled rolling is widely used to strengthen flat sheet made of lowarbon pipe steel. The structure and hence the properties depend not only on the tem? perature and deformation in rolling but also on the cooling after deformation (1, 2). In the case of air cooling, the pipe steel will predominantly contain the products of diffusional transformation of supercooled

I. Yu. Pyshmintsev; A. N. Boryakova; M. A. Smirnov; V. I. Krainov

2010-01-01

250

Microstructure and Properties of SAE 2205 Stainless Steel After Salt Bath Nitrocarburizing at 450 C  

NASA Astrophysics Data System (ADS)

Nitrocarburizing of the type SAE 2205 duplex stainless steel was conducted at 450 C, using a type of salt bath chemical surface treatment, and the microstructure and properties of the nitrided surface were systematically researched. Experimental results revealed that a modified layer transformed on the surface of samples with the thickness ranging from 3 to 28 ?m changed with the treatment time. After 2205 duplex stainless steel was subjected to salt bath nitriding at 450 C for time less than 8 h, the preexisting ferrite zone in the surface transformed into austenite by active nitrogen diffusion. The main phase of the nitrided layer was the expanded austenite. When the treatment time was extended to 16 h, the preexisting ferrite zone in the expanded austenite was decomposed and transformed partially into ?-nitride precipitate. When the treatment time extended to 40 h, the preexisting ferrite zone in the expanded austenite was transformed into ?-nitride and CrN precipitate. Further, a large amount of nitride precipitated from preexisting austenite zone. The nitrided layer depth thickness changed intensively with the increasing nitriding time. The growth of the nitride layer takes place mainly by nitrogen diffusion according to the expected parabolic rate law. The salt bath nitriding can effectively improve the surface hardness. The maximum values measured from the treated surface are observed to be approximately 1400 HV0.1 after 8 h, which is about 3.5 times as hard as the untreated material (396 HV0.1). Low-temperature nitriding can improve the erosion/corrosion resistance. After nitriding for 4 h, the sample has the best corrosion resistance.

Yan, Jing; Wang, Jun; Lin, Yuanhua; Gu, Tan; Zeng, Dezhi; Huang, Runbo; Ji, Xiong; Fan, Hongyuan

2014-04-01

251

Comparative studies on shielding properties of some steel alloys using Geant4, MCNP, WinXCOM and experimental results  

NASA Astrophysics Data System (ADS)

The mass attenuation coefficients, ?/? and effective atomic numbers, Zeff of some carbon steel and stainless steel alloys have been calculated by using Geant4, MCNP simulation codes for different gamma ray energies, 279.1 keV, 661.6 keV, 662 keV, 1115.5 keV, 1173 keV and 1332 keV. The simulation results of Zeff using Geant4 and MCNP codes have been compared with possible available experimental results and theoretical WinXcom, and good agreement has been observed. The simulated ?/? and Zeff values using Geant4 and MCNP code signifies that both the simulation process can be followed to determine the gamma ray interaction properties of the alloys for energies wherever analogous experimental results may not be available. This kind of studies can be used for various applications such as for radiation dosimetry, medical and radiation shielding.

Singh, Vishwanath P.; Medhat, M. E.; Shirmardi, S. P.

2015-01-01

252

Evaluation of hard coatings obtained on AISI D2 steel by thermo-reactive deposition treatment  

Microsoft Academic Search

Niobium carbide, vanadium carbide and iron boride layers were obtained on AISI D2 steel by thermo-reactive treatments in different borax baths, containing ferroniobium, ferrovanadium or ferrotitanium, and aluminum. Vickers microhardness and micro-abrasive (ball crater) wear tests were used to evaluate the tribologic properties of the layers. Hardness values of the niobium carbide layer and the vanadium carbide layer, having depths

C. K. N. Oliveira; C. L. Benassi; L. C. Casteletti

2006-01-01

253

Evaluation of microstructure and mechanical properties in friction stir processed SKD61 tool steel  

SciTech Connect

A SKD61 tool steel was friction stir processed using a polycrystalline cubic boron nitride tool. Microstructure, tensile properties and wear characteristic were evaluated. Fine grains with a martensite structure were produced in the friction stir processed zone, which led to the increase of the microindentation hardness. The grains became finer when the heat input was lowered. The transverse tensile strength of the friction stir processed zone was equal to that of base metal and all the tensile specimens fractured at base metal zone. The wear width and depth of the friction stir processed zone at the load of 1.96 N were 339 {mu}m and 6 {mu}m, as compared to 888 {mu}m and 42 {mu}m of the base metal, decreased by 62% and 86%. Findings of the present study suggest that low heat input is an effective method to produce a friction stir processed zone composed of relatively fine grain martensitic structure with good tensile properties and wear characteristic.

Chen, Y.C., E-mail: armstrong@hit.edu.cn [Joining and Welding Research Institute, Osaka University, Osaka 567-0047 (Japan); Nakata, K. [Joining and Welding Research Institute, Osaka University, Osaka 567-0047 (Japan)

2009-12-15

254

TEM analysis of centreline sulphide precipitates modified by titanium additions to low carbon steel.  

PubMed

Elongated inclusions, particularly MnS, contribute significantly to reduced ductility and toughness in hot rolled steel but earlier research indicated that these properties can be improved by titanium additions. Such additions to a steel result in titanium being dissolved in manganese sulphide or MnS being replaced by TiS and/or titanium carbosulphides. In the present study, a steel was designed to decrease alloying element segregation and to evaluate the effect of titanium on centreline sulphide precipitates. Precipitates were identified by using scanning electron microscopy and characterized by the use of transmission electron microscopy following sample preparation by focused ion beam milling techniques. Iron-titanium-sulphides form in close proximity to MnS precipitates that contain iron. Evidence is provided that an increase in the titanium content of steel leads to an increase in the percentage of titanium contained in the iron sulphides and a decrease in the iron content of MnS inclusions. PMID:19017209

Aminorroaya, S; Dippenaar, R

2008-10-01

255

Mechanical and Electro-Chemical Properties of Laser Surface Alloyed AISI 304 Stainless Steel with WC+Ni+NiCr  

NASA Astrophysics Data System (ADS)

In the present study, a detailed evaluation of wear and corrosion resistance properties of laser surface alloyed of AISI 304 stainless steel with WC+Ni+NiCr (in the ratio of 70:15:15) has been undertaken. Laser processing has been carried out using a 5 kW continuous wave (CW) Nd:YAG laser (at a beam diameter of 3 mm) by surface melting and simultaneous deposition of precursor powder mixture in the melt zone (at a flow rate of 10 mg/s) and using Ar shroud at a gas flow rate of 5 l/min. Followed by laser processing, a detailed evaluation of fretting wear behavior has been conducted against WC surface. Finally, the corrosion property is measured using a potentiodynamic polarization testing unit in a 3.56 wt.% NaCl solution. The wear resistance property is significantly improved due to laser surface alloying which is attributed to the improvement in surface microhardness to 1350 VHN as compared to 220 VHN of as-received ?-stainless steel substrate. The mechanism of wear is established. The pitting corrosion resistance property is also improved due to the presence of Ni and Cr in solution and homogenization of microstructure due to laser processing.

Majumdar, J. D.

256

Particles into 410L Stainless Steel by a Powder Metallurgy Route  

NASA Astrophysics Data System (ADS)

Addition of yttria to steels has been proposed for the fabrication of oxide-dispersion-strengthened materials for nuclear power applications. We have investigated materials prepared from 12 Cr martensitic stainless steel, AISI 410L, produced by powder metallurgy. Materials were produced with and without yttria addition, and two different sizes of yttria were used, 0.9 m and 50 nm. Tensile and mini-creep tests were performed to determine mechanical properties. Optical microscopy, SEM, TEM, and EDX analysis were used to investigate the microstructures and deformation mechanisms and to obtain information about non-metallic inclusion particles. SiO2, MnS, and Y2Si2O7 inclusion particles were observed. An SiO2 and Y2O3 interaction was seen to have occurred during the ball milling, which impaired the final mechanical properties. Small-angle neutron scattering experiments showed that the matrix chemistry prevented effective dissolution of the yttria.

Zeybek, A.; Barroso, S. Pirfo; Chong, K. B.; Edwards, L.; Fitzpatrick, M. E.

2014-06-01

257

Interaction of Benzimidazoles and Benzotriazole: Its Corrosion Protection Properties on Mild Steel in Hydrochloric Acid  

NASA Astrophysics Data System (ADS)

Synergistic hydrogen-bonded interaction of alkyl benzimidazoles and 1,2,3-benzotrizole and its corrosion protection properties on mild steel in hydrochloric acid at different temperatures have been studied using polarization, EIS, adsorption, surface studies, and computational methods. The extent of synergistic interaction increases with temperature. Quantum chemical approach is used to calculate some electronic properties of the molecules and to ascertain the synergistic interaction, inhibitive effect, and molecular structures. The corrosion inhibition efficiencies and the global chemical reactivity relate to some parameters, such as total energy, E HOMO, E LUMO, and gap energy (? E). 1,2,3-Benzotrizole interacts with benzimidazoles derivatives up to a bond length of approximately 1.99 . This interaction represents the formation of a hydrogen bond between the 1,2,3-benzotrizole and benzimidazoles. This synergistic interaction of 1,2,3-benzotrizole and benzimidazole derivatives offers extended inhibition efficiency toward mild steel in hydrochloric acid.

Ramya, K.; Mohan, Revathi; Joseph, Abraham

2014-11-01

258

Grafting of HEMA onto dopamine coated stainless steel by 60Co-? irradiation method  

NASA Astrophysics Data System (ADS)

A novel method for grafting of 2-hydroxyethyl methacrylate (HEMA) onto the surface of stainless steel (SS) was explored by using 60Co-? irradiation. The surface of SS was modified by coating of dopamine before radiation grafting. The grafting reaction was performed in a simultaneous irradiation condition. The chemical structures change of the surface before and after grafting was demonstrated by Fourier transform infrared (FTIR) spectrometer. The hydrophilicity of the samples was determined by water contact angle measurement in the comparison of the stainless steel in the conditions of pristine, dopamine coated and HEMA grafted. Surface morphology of the samples was characterized by atomic force microscope (AFM) and scanning electron microscope (SEM). The corrosion resistance properties of the samples were evaluated by Tafel polarization curve. The hemocompatibility of the samples were tested by platelet adhesion assay.

Jin, Wanqin; Yang, Liming; Yang, Wei; Chen, Bin; Chen, Jie

2014-12-01

259

Tensile properties of martensitic stainless steels at elevated temperatures  

Microsoft Academic Search

Tensile properties of quenched and tempered martensitic alloys EP-823, HT-9, and 422 were evaluated at temperatures ranging\\u000a from ambient to 600 C as a function of three different tempering times. The results indicated that the yield strength, ultimate\\u000a tensile strength, and the failure strength were gradually reduced with increasing temperature. The ductility parameters were\\u000a enhanced at elevated temperatures due to

A. K. Roy; S. R Kukatla; B. Yarlagadda; V. N. Potluri; M. Lewis; M. Jones; B. J. OToole

2005-01-01

260

Effects of laser power density on static and dynamic mechanical properties of dissimilar stainless steel welded joints  

NASA Astrophysics Data System (ADS)

The mechanical properties of laser welded joints under impact loadings such as explosion and car crash etc. are critical for the engineering designs. The hardness, static and dynamic mechanical properties of AISI304 and AISI316 L dissimilar stainless steel welded joints by CO2 laser were experimentally studied. The dynamic strain-stress curves at the strain rate around 103 s-1 were obtained by the split Hopkinson tensile bar (SHTB). The static mechanical properties of the welded joints have little changes with the laser power density and all fracture occurs at 316 L side. However, the strain rate sensitivity has a strong dependence on laser power density. The value of strain rate factor decreases with the increase of laser power density. The welded joint which may be applied for the impact loading can be obtained by reducing the laser power density in the case of welding quality assurance.

Wei, Yan-Peng; Li, Mao-Hui; Yu, Gang; Wu, Xian-Qian; Huang, Chen-Guang; Duan, Zhu-Ping

2012-10-01

261

Niobium-Alloyed high speed steel by powder metallurgy  

NASA Astrophysics Data System (ADS)

A philosophy for the use of strong carbide formers like niobium in high speed steels is described. It follows the concept of independently optimizing the compositions of the matrix (for maximum secondary hardening potential) and the volume fraction of the blocky carbides (for protection against abrasive wear). Normally, the two are interdependent through the action of the solidification equilibria, but separate control becomes possible when the blocky carbides are formed by a strong carbide former such as niobium. During normal ingot solidification, such strong carbide formers would produce very large primary carbides. This can be avoided by atomization and powder metallurgical processing. In this way, a steel has been produced whose matrix composition is similar to that of AISI M2, and whose primary carbides are all of NbC type. Its composition is 1.3C, 2W, 3Mo, 1.6V, 3.2Nb (wt pct). Because of its high stability, NbC is a much more effective obstacle to grain growth than the normal high speed steel carbides, and this allows substantially higher austenitization temperatures to be used. Despite its leaner composition, the Nb-alloyed steel matches the cutting performance of AISI M2, and its secondary hardening seems to be more persistent at high temperatures.

Karagz, S.; Fischmeister, H. F.

1988-06-01

262

Niobium-alloyed high speed steel by powder metallurgy  

SciTech Connect

A philosophy for the use of strong carbide formers like niobium in high speed steels is described. It follows the concept of independently optimizing the compositions of the matrix (for maximum secondary hardening potential) and the volume fraction of the blocky carbides (for protection against abrasive wear). Normally, the two are interdependent through the action of the solidification equilibria, but separate control becomes possible when the blocky carbides are formed by a strong carbide former such as niobium. During normal ingot solidification, such strong carbide formers would produce very large primary carbides. This can be avoided by atomization and powder metallurgical processing. In this way, a steel has been produced whose matrix composition is similar to that of AISI M2, and whose primary carbides are all of NbC type. Its composition is 1.3C, 2W, 3Mo, 1.6V, 3.2Nb (wt pct). Because of its high stability, NbC is a much more effective obstacle to grain growth than the normal high speed steel carbides, and this allows substantially higher austenitization temperatures to be used. Despite its leaner composition, the Nb-alloyed steel matches the cutting performance of AISI M2, and its secondary hardening seems to be more persistent at high temperatures.

Karagoz, S.; Fischmeister, H.F.

1988-06-01

263

Weld microstructure development and properties of precipitation-strengthened martensitic stainless steels  

Microsoft Academic Search

The weld microstructural evolution, mechanical properties and solidification cracking susceptibility of three precipitation-strengthened martensitic stainless steels--PH 13-8 Mo, Custom 450 and 15-5 PH--were investigated. Liquid tin quenching of gas tungsten arc welds revealed that all three welds solidified as single-phase ferrite with a high degree of microsegregation. However, during further solidification and cooling almost complete homogenization occurred as a result

J. A. Brooks; W. R. Jr. Garrison

1999-01-01

264

Hydrogen effects on the tensile properties of 21-6-9 stainless steel  

Microsoft Academic Search

The effect of hydrogen on the mechanical properties of a series of nineteen experimental heats of 21-6-9 stainless steel was\\u000a investigated. The nineteen material groups covered a variety of forging processes, strength levels, grain sizes, and microstructures.\\u000a The data show that absorbed hydrogen acts as an interstitial strengthener which increases the flow stress of 21-6-9 similar\\u000a to the effects of

McIntyre R. Louthan

1982-01-01

265

Tensile and fatigue properties of 17-4 PH stainless steel at high temperatures  

Microsoft Academic Search

The tensile and high-cycle fatigue properties for 17-4 PH* stainless steels in three different conditions were investigated\\u000a at temperatures ranging from room temperature to 400 C. Results indicated that the yield strength and fatigue strength for\\u000a the three conditions at a given temperature took the following order: condition H900 > condition A> condition H1150. The yield\\u000a strength of each condition

Jui-Hung Wu; Chih-Kuang Lin

2002-01-01

266

Tribological properties of alcohols as lubricating additives for aluminum-on-steel contact  

Microsoft Academic Search

The tribological properties of a series of alcohols as lubricating additives in liquid paraffin were investigated using a Timken tester with a SAE52100 steel ring sliding against an Al 2024 block. The boundary film formed on the aluminum block was studied with X-ray photoelectron spectrometry (XPS) and scanning electron microscopy (SEM). It was found that these compounds possess high load-carrying

Yanhong Hu; Weimin Liu

1998-01-01

267

Influence of initial structure of tube steel on its mechanical properties after quenching from intercritical range  

NASA Astrophysics Data System (ADS)

The effect of the initial microstructure of low-alloy tube steel 13KhFA on its mechanical properties after quenching from the intercritical temperature range (ICR) has been studied. It has been established that the maximum impact toughness KCV-80 is achieved in the case of the initial quenched structure, and the lowest values correspond to the initial annealing. The dependences of the KCV-80 on the temperature of the second quenching for these initial states are fundamentally different as well.

Makovetskii, A. N.; Mirzaev, D. A.

2014-06-01

268

Effect of Grain Refinement on the Mechanical Properties of a Nickel- and Manganese-Free High Nitrogen Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

Grain coarsening due to the high temperature exposure deteriorates mechanical properties of the high nitrogen austenitic stainless steels (HNASSs) produced by solution nitriding. To improve mechanical properties, the grains of nickel and manganese-free Fe-23Cr-2.4Mo-1.2N HNASS plates fabricated by pressurized solution nitriding were refined using a two-stage heat treatment process. Structural and mechanical properties were investigated using X-ray diffraction, optical microscopy, scanning and transmission electron microscopy, hardness and tensile testing and compared with that of the conventional AISI 316L steel. The results show that the as-produced HNASS exhibits uniform deformation up to failure without necking and brittle inter-granular fracture. By grain refinement, the yield and tensile strengths as well as the elongation to failure are increased by 17.8, 21.2, and 108.3 pct, respectively, as compared to the as-produced HNASS. However, despite more than a double increase in tensile toughness and elongation to failure, the brittle inter-granular fracture is not suppressed. The HNASSs plastically deform through formation of straight slip bands. TEM observations indicate development of planar arrays of dislocations in tensile-deformed HNASSs. The enhancement in tensile strength and toughness by grain refinement is discussed on the basis of straight slip bands formation, number of dislocations in pile-ups, and incompatibility strain developed between adjacent grains.

Akbari, Alireza; Mohammadzadeh, Roghayeh

2015-01-01

269

Development of low-temperature high-strength integral steel castings for offshore construction by casting process engineering  

NASA Astrophysics Data System (ADS)

In casting steels for offshore construction, manufacturing integral casted structures to prevent fatigue cracks in the stress raisers is superior to using welded structures. Here, mold design and casting analysis were conducted for integral casting steel. The laminar flow of molten metal was analyzed and distributions of hot spots and porosities were studied. A prototype was subsequently produced, and air vents were designed to improve the surface defects caused by the release of gas. A radiographic test revealed no internal defects inside the casted steel. Evaluating the chemical and mechanical properties of specimens sampled from the product revealed that target values were quantitatively satisfied. To assess weldability in consideration of repair welding, the product was machined with grooves and welded, after which the mechanical properties of hardness as well as tensile, impact, and bending strengths were evaluated. No substantive differences were found in the mechanical properties before and after welding.

Lim, Sang-Sub; Mun, Jae-Chul; Kim, Tae-Won; Kang, Chung-Gil

2014-12-01

270

Prediction of carbon steel heat-affected zone microstructure induced by electroslag cladding  

SciTech Connect

One of the major concerns in developing electroslag cladding technique is the mechanical properties of the clad heat-affected zone. During the cladding operation, the base metal adjacent to the clad deposit undergoes intensive heating and fast cooling. Mechanical properties of this area are different from, and in most cases inferior to, those of the base metal due to the formation of undesirable microstructure which results from the thermal cycle. To optimize mechanical properties of clad components, steps must be taken to optimize the HAZ microstructure, which is determined by the cladding heat input, geometry of the components, chemistry of the steel, and the thermodynamics and kinetics of phase transformations. There are four main methods for predicting HAZ hardness and microstructure: weld simulation experiments, CCT diagrams, regression analysis based on the carbon equivalents of steels and hardenability studies, and the computational models based on phase transformationkineticss and thermodynamics. The computational approach was adopted in the study to predict the carbon steel HAZ microstructure evolution during electroslag cladding because it is a general approach applicable to a wide range of chemical compositions and welding conditions. The computation model in the study incorporates a grain growth model and a model for austenite decomposition. The empirical grain growth kinetics models and the reaction kinetics model for austenite decomposition originally proposed by Kirkaldy and Venugopalan were calibrated with experimental studies and then coded into a computer program to predict microstructure development. Reasonable agreement was observed between the computer predictions and experimental observations; discrepanciesweree also discussed.

Li, M.V.; Atteridge, D.G.

1994-12-31

271

Anisotropy of Dynamic Compressive Properties of Non-Heat-Treating Cold-Heading-Quality Steel Bars  

NASA Astrophysics Data System (ADS)

In the current study, a non-heat-treating cold-heading-quality steel bar was fabricated by cold drawing of a rolled bar, and anisotropic mechanical properties of the as-rolled and cold-drawn bars were investigated by quasistatic and dynamic compressive tests of 0 deg (longitudinal)-, 45 deg-, and 90 deg (transverse)-orientation specimens. Under the dynamic compressive loading, the trend of strength variation was similar to that of the quasistatic compressive loading, while the strength level was considerably increased by the strain rate hardening effect. Stress-strain curves of the cold-drawn bar specimens showed the nearly same strain hardening behavior, irrespective of specimen orientation and strain rate, but the yield stress and compressive flow stress increased in the order of the 0 deg-, 90 deg-, and 45 deg-orientation specimens. In the 45 deg- and 90 deg-orientation specimens, the pearlite bands had the stronger resistance to the stress acting on the maximum shear stress plane than in the 0 deg-orientation specimens, thereby resulting in the higher strengths. In some dynamically compressed specimens, pearlite bands were dissolved to form bainitic microstructures. Locations of these bainitic microstructures were well matched with hemispherical-shaped heat-trap zones, which confirmed that bainitic microstructures were formed by the temperature rise occurring during the dynamic compressive loading.

Kim, Hyunmin; Kang, Minju; Bae, Chul Min; Kim, Hyoung Seop; Lee, Sunghak

2014-01-01

272

The Effects of Cooling Mode on Precipitation and Mechanical Properties of a Ti-Nb Microalloyed Steel  

NASA Astrophysics Data System (ADS)

Laboratory experiments of a high-strength Ti-Nb microalloyed steel were conducted with two cooling modes, i.e., a large (35 C s-1) cooling rate in the initial stage followed by slow (8.5 C s-1) cooling rate (termed as FFC) and a slow (8.5 C s-1) cooling rate in the initial stage followed by large (35 C s-1) cooling rate (LFC) during cooling process. Based on the results of laboratory experiments, an industrial trial was performed with similar steel on a continuous hot strip production mill. The grain size in LFC sample (2.83 ?m) is smaller than that in FFC sample (3.80 ?m), and the volume fraction of precipitates in LFC sample (1.04%) is more than that in FFC sample (0.81%). Both results of laboratory experiments and industrial tests confirm that the strengthening effect of the LFC mode is much better than that of the FFC mode from the viewpoints of both fine-grain strengthening and precipitation strengthening. The present study provides a new approach to improve the property of microalloyed steels produced by continuous hot rolling technology.

Hu, Zhangwei; Xu, Guang; Yang, Hailin; Zhang, Chen; Yu, Ru

2014-12-01

273

An AES and ESCA study of GCr15 steel coated with Ti, Cr and bombarded by N + and Ar +  

NASA Astrophysics Data System (ADS)

GCr15 steel specimens coated with Ti, Cr and bombarded with N +, Ar + were analyzed by AES and ESCA (PHI-550). The results show that (1) the specimens bombarded with N + have improved surface mechanical properties compared to those bombarded with Ar +; (2) the changes in the surface properties are related to the composition of the surface layer, mainly to TiO 2, TiN, Cr 2O 3, and other compounds. Also, the presence of carbon is found to be advantageous in modifying GCr15 bearing steel.

Jie, Zhao; Wang, Li; Yawen, Su; Srivastava, S. C.

1988-07-01

274

Microstructure and property examination of the weld HAZ in Grade 100 microalloyed steel  

NASA Astrophysics Data System (ADS)

The microstructure and mechanical property variations across different regions of the heat-affected zone (HAZ) of a Grade 100 microalloyed steel were examined for a range of heat inputs from 0.5 to 2.5 kJ/mm. Autogenous gas tungsten arc welding was performed on plates of Grade 100 steel to create the HAZ. The weld thermal cycles were recorded by embedding thermocouples at different locations in the plates. Examination of precipitate alterations (dissolution, coarsening and reprecipitation) was carried out theoretically and/or experimentally using transmission electron microscopy (TEM). Iron matrix phase transformations and grain size changes were examined with optical microscopy as well as TEM (both thin foils and carbon replicas). Hardness measurements (macro-, micro- and nano-hardness) were mainly used for examination of mechanical properties across the HAZ. Hardness measurements across the HAZ showed hardening in 0.5 kJ/mm weld samples and softening in the 1.5 and 2.5 kJ/mm weld samples. This was mainly due to the difference in cooling rates, since fast cooling results in microstructures with finer structures (especially grain size) and higher levels of solutes and sub-structure in the matrix. The coarse-grained HAZ (CGHAZ) had a higher hardness relative to the fine-grained HAZ (FGHAZ), regardless of the heat input, due to the formation of bainitic and martensitic fine structures (laths/plates) inside large prior austenite grains. The CGHAZ-0.5 kJ/mm consisted of packets of untempered lath martensite and coarse regions of autotempered martensite or aged massive ferrite. Increasing the heat input to 1.5 and 2.5 kJ/mm resulted in mainly bainitic microstructures (e.g., granular bainite) with some acicular ferrite and grain-boundary ferrite in the CGHAZ. The FGHAZ was mainly made up of polygonal ferrite, with considerable amounts of bainitic ferrite in the case of the 0.5 kJ/mm weld sample. Nb-rich carbides mostly survived the thermal cycles experienced in FGHAZ, but were dissolved in the CGHAZ due to exposure to higher temperatures. Ti-rich nitrides mostly survived even in the CGHAZ, but they had limited contribution to grain growth control due to their coarse distribution in the base metal. Transformation twins were observed in some regions across the HAZ. Their formation is believed to relieve high thermal, solidification-induced and transformation-induced stresses, at places where deformation by slipping was not achievable.

Poorhaydari-Anaraki, Kioumars

275

Liquid metal embrittlement susceptibility of T91 steel by leadbismuth  

Microsoft Academic Search

Previous studies on T91 steel in its standard metallurgical state do not provide evidence for liquid metal embrittlement by eutectic PbBi. In this paper, we show that this steel can be embrittled by PbBi when direct contact between the steel and the liquid metal is obtained by prior ion beam sputtering of the native oxidized film.

T. Auger; G. Lorang

2005-01-01

276

Susceptibility to LME of 316L and T91 steels by LBE: Effect of strain rate  

NASA Astrophysics Data System (ADS)

The effect of liquid lead-bismuth eutectic on 316L and T91 steels at 160 C has been studied as a function of strain rate, using a centre cracked in tension specimen adapted for the study of crack propagation. Brittle fracture, characterized by elongated river cracks on all the fracture surfaces, indicates that T91 is sensitive to the embrittlement by LBE. This embrittlement effect is very pronounced at low deformation rate (10 -5 mm s -1). A ductile-brittle transition is observed in the high strain rate range investigated. In the transitory regime, there is a competition between the growth of dimples and brittle cracking induced by the liquid metal. Ductility recovery is complete at the highest investigated deformation rate. The mechanical properties of the 316L steel are not clearly affected by the presence of LBE, in spite of a modification in the plastic deformation mode which strongly affects fracture surfaces.

Hamouche-Hadjem, Zehoua; Auger, Thierry; Guillot, Ivan; Gorse, Dominique

2008-06-01

277

Charpy toughness and tensile properties of a neutron irradiated stainless steel submerged-arc weld cladding overlay  

SciTech Connect

The possibility of stainless steel cladding increasing the resistance of an operating nuclear reactor pressure vessel to extension of surface flaws is highly dependent upon the irradiated properties of the cladding. Therefore, weld overlay cladding irradiated at temperatures and fluences relevant to power reactor operation was examined. The cladding was applied to a pressure vessel steel plate by the submerged-arc, single-wire, oscillating electrode method. Three layers of cladding were applied to provide a cladding thickness adequate for fabrication of test specimens. The first layer was type 309, and the upper two layers were type 308 stainless steel. There was considerable dilution of the type 309 in the first layer of cladding as a result of excessive melting of the base plate. Specimens for the irradiation study were taken from near the base plate/cladding interface and also from the upper layers of cladding. Charpy V-notch and tensile specimens were irradiated at 288/sup 0/C to neutron fluences of 2 x 10/sup 23/ n/m/sup 2/ (E > 1 MeV). When irradiated, both types 308 and 309 cladding showed a 5 to 40% increase in yield strength accompanied by a slight increase in ductility in the temperature range from 25 to 288/sup 0/C. All cladding exhibited ductile-to-brittle transition behavior during impact testing.

Corwin, W.R.; Berggren, R.G.; Nanstad, R.K.

1984-01-01

278

Temper embrittlement of Ni-Cr Steels by phosphorus  

Microsoft Academic Search

Temper embrittlement in 3.5 pct Ni, 1.7 pct Cr steels doped with P and isothermally aged at several temperatures was studied\\u000a by measurements of ductile-to-brittle transition temperature and hardness, which were correlated with observations of the\\u000a intergranular fracture surfaces by Auger electron spectroscopy and scanning electron fractography. It is shown that if all\\u000a other factors remain constant, the effect of

R. A. Mulford; C. J. Mcmahon; D. P. Pope; H. C. Feng

1976-01-01

279

Corrosion resistance of stainless steel coatings elaborated by solar cladding process  

Microsoft Academic Search

The resistance to corrosion of stainless steel coatings deposited onto carbon steel substrate with a solar processing is analyzed. The solar cladding consists in melting the powder of stainless steel AISI 316 under a beam of concentrated solar energy, followed by a rapid solidification. A continuous scanning process is performed by moving the specimen at controlled speed, according to the

A. Ferriere; C. Sanchez Bautista; G. P. Rodriguez; A. J. Vazquez

2006-01-01

280

Tensile Properties of Under-Matched Weld Joints for 950 MPa Steel.  

NASA Astrophysics Data System (ADS)

In welding of 950 MPa-class high tensile strength steel, preheating is crucial in order to avoid cold cracks, which, however, eventually increases welding deformations. One way to decrease welding deformations is lowering preheating temperature by using under-matched weld metal. Toyota and others clarify that although breaking elongation can decrease due to plastic constraint effect under certain conditions, static tensile of under-matched weld joints is comparable to that of base metal. However, there has still been no report about joint static tensile of under-matched weld joints applied to 950 MPa-class high tensile strength steel. In this study, we aim to research tensile strength and fatigue strength of under-matched weld joints applied to 950 MPa-class high tensile steel.

Yamamoto, Kouji; Arakawa, Toshiaki; Akazawa, Nobuki; Yamamoto, Kousei; Matsuo, Hiroki; Nakagara, Kiyoyuki; Suita, Yoshikazu

281

Properties of FERRALIUM alloy 255 duplex austenitic-ferritic stainless steel for sour gas well applications  

SciTech Connect

Some of the properties of a 25 pct chromium duplex stainless steel, FERRALIUM /SUP R/ alloy 255,* as related to sour gas well applications are presented. Autoclave tests have demonstrated negligible corrosion rates in NaCl/sub -/, CO/sub 2//sup -/, and H/sub 2/S-containing environments to 200/sup 0/C (400/sup 0/F). The steel exhibited resistance to environmental embrittlement for a broad range of H/sub 2/S concentrations. At high H/sub 2/S concentrations stress corrosion cracking (SCC) occurs. Sigma phase formation is detrimental to SCC resistance. Heat treatments at temperatures of 1040/sup 0/C to 1150/sup 0/C (1900/sup 0/F to 2100/sup 0/F), which are above the sigma-phase formation temperatures, did not have a measurable effect on SCC as determined with plastically deformed two-point beam specimens.

Kolts, J.

1983-09-01

282

Mechanical properties and oxidation and corrosion resistance of reduced-chromium 304 stainless steel alloys  

NASA Technical Reports Server (NTRS)

An experimental program was undertaken to identify effective substitutes for part of the Cr in 304 stainless steel as a method of conserving the strategic element Cr. Although special emphasis was placed on tensile properties, oxidation and corrosion resistance were also examined. Results indicate that over the temperature range of -196 C to 540 C the yield stress of experimental austenitic alloys with only 12 percent Cr compare favorably with the 18 percent Cr in 304 stainless steel. Oxidation resistance and in most cases corrosion resistance for the experimental alloys were comparable to the commercial alloy. Effective substitutes for Cr included Al, Mo, Si, Ti, and V, while Ni and Mn contents were increased to maintain an austenitic structure.

Stephens, J. R.; Barrett, C. A.; Gyorgak, C. A.

1979-01-01

283

TRITIUM AND DECAY HELIUM EFFECTS ON THE FRACTURE TOUGHNESS PROPERTIES OF STAINLESS STEEL WELDMENTS  

SciTech Connect

J-Integral fracture toughness tests were conducted on tritium-exposed-and-aged Types 304L and 21-6-9 stainless steel weldments in order to measure the combined effects of tritium and its decay product, helium-3 on the fracture toughness properties. Initially, weldments have fracture toughness values about three times higher than base-metal values. Delta-ferrite phase in the weld microstructure improved toughness provided no tritium was present in the microstructure. After a tritium-exposure-and-aging treatment that resulted in {approx}1400 atomic parts per million (appm) dissolved tritium, both weldments and base metals had their fracture toughness values reduced to about the same level. The tritium effect was greater in weldments (67 % reduction vs. 37% reduction) largely because the ductile discontinuous delta-ferrite interfaces were embrittled by tritium and decay helium. Fracture toughness values decreased for both base metals and weldments with increasing decay helium content in the range tested (50-200 appm).

Morgan, M; Scott West, S; Michael Tosten, M

2007-08-31

284

Liquid metal embrittlement of 4145 steel by lead alloys  

Microsoft Academic Search

It has been found that 4145 high strength steel specimens tested over a specific temperature range will be embrittled when\\u000a externally wetted by pure lead. Additions of small amounts of either tin and antimony to pure lead has been found to intensify\\u000a the severity of the embrittlement and to extend the critical temperature range. The effect of second element content

M. Landow; A. Harsolia; N. N. Breyer

1981-01-01

285

Alloy Design, Combinatorial Synthesis, and Microstructure-Property Relations for Low-Density Fe-Mn-Al-C Austenitic Steels  

NASA Astrophysics Data System (ADS)

We present recent developments in the field of austenitic steels with up to 18% reduced mass density. The alloys are based on the Fe-Mn-Al-C system. Here, two steel types are addressed. The first one is a class of low-density twinning-induced plasticity or single phase austenitic TWIP (SIMPLEX) steels with 25-30 wt.% Mn and <4-5 wt.% Al or even <8 wt.% Al when naturally aged. The second one is a class of ?-carbide strengthened austenitic steels with even higher Al content. Here, ?-carbides form either at 500-600C or even during quenching for >10 wt.% Al. Three topics are addressed in more detail, namely, the combinatorial bulk high-throughput design of a wide range of corresponding alloy variants, the development of microstructure-property relations for such steels, and their susceptibility to hydrogen embrittlement.

Raabe, D.; Springer, H.; Gutierrez-Urrutia, I.; Roters, F.; Bausch, M.; Seol, J.-B.; Koyama, M.; Choi, P.-P.; Tsuzaki, K.

2014-09-01

286

Gleeble Testing to Assess Solid\\/Liquid Metal Embrittlement of Gun Steels by Copper  

Microsoft Academic Search

Gleeble testing was performed to assess the solid\\/liquid metal embrittlement of gun steels by copper. An interior ballistics and finite element model provided the maximum bore temperatures in a 155mm gun after aggressive firing. Specimens were manufactured out of three different steels. Testing was performed on bare steel as well as copper plated specimens at temperatures ranging from 868C to

G. N. Vigilante; S. Bartolucci; J. Izzo; M. Witherell; S. B. Smith

2012-01-01

287

Radiation attenuation and nuclear properties of high density concrete made with steel aggregates  

NASA Astrophysics Data System (ADS)

The fast neutron and gamma ray spectra measured behind different thickness of steel scrap concrete with density of 4 g/cm3 have been studied. The mix proportions by weight of this type of concrete were 1 cement: 6.89 steel scrap: 2.9 sand and 0.5 Water. Comparison with a standard ordinary concrete of density 2.3 g/cm3 have been carried out. The measurements were made using a collimated beam of both gamma rays and neutrons emitted from one of the horizontal channel of the Egyptian Research Reactor-1. A fast neutron and gamma ray spectrometer with a stilbene crystal was used to measure the spectra of fast neutrons and gamma rays. Pulse shape discrimination using the zero cross over technique was used to separate the photon pulses from the electron pulses. The equation due to Schmidt has been modified and applied for determining the neutron effective removal cross sections (R) for steel scrap, ordinary, hematite-serpentine, ilmenite-limonite and ilmenite concretes. This equation gives results which are in good agreement with the measured values. The derived empirical equation in a previous work to calculate the neutron integral flux behind different thicknesses of different types of concretes, gives good results for steel scrap concrete under investigation comparing with the corresponding experimental data. Total neutron macroscopic cross sections, linear attenuation coefficients for gamma rays and the half-value layers for both radiations at different energies have been obtained for steel scrap concrete and comparing with the corresponding values of ordinary concrete. The results show that steel scrap concrete is better than ordinary, hematite-serpentine, ilmenite-limonite and ilmenite concretes from the radiation shielding point of view.

Bashter, I. I.

288

Optimization of chemical compositions in low-carbon Al-killed enamel steel produced by ultra-fast continuous annealing  

SciTech Connect

The influence of Mn,S and B contents on microstructural characteristics, mechanical properties and hydrogen trapping ability of low-carbon Al-killed enamel steel was investigated. The materials were produced and processed in a laboratory and the ultra-fast continuous annealing processing was performed using a continuous annealing simulator. It was found that increasing Mn,S contents in steel can improve its hydrogen trapping ability which is attributed by refined ferrite grains, more dispersed cementite and added MnS inclusions. Nevertheless, it deteriorates mechanical properties of steel sheet. Addition of trace boron results in both good mechanical properties and significantly improved hydrogen trapping ability. The boron combined with nitrogen segregating at grain boundaries, cementite and MnS inclusions, provides higher amount of attractive hydrogen trapping sites and raises the activation energy for hydrogen desorption from them. - Highlights: We study microstructures and properties in low-carbon Al-killed enamel steel. Hydrogen diffusion coefficients are measured to reflect fish-scale resistance. Manganese improves hydrogen trapping ability but decrease deep-drawing ability. Boron improves both hydrogen trapping ability and deep-drawing ability. Both excellent mechanical properties and fish-scale resistance can be matched.

Dong, Futao, E-mail: dongft@sina.com [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Du, Linxiu; Liu, Xianghua [The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Xue, Fei [College of Electrical Engineering, Hebei United University, Tangshan 063000 (China)

2013-10-15

289

Mechanical Properties of Steel Surfaces Coated with HfN/VN Superlattices  

NASA Astrophysics Data System (ADS)

Mechanical and tribological evolution on 4140 steel surfaces coated with hafnium nitride/vanadium nitride [HfN/VN] n multilayer systems deposited in various bilayer periods (?) via magnetron sputtering has been exhaustively studied in this work. The coatings were characterized in terms of structural, chemical, morphological, mechanical, and tribological properties by x-ray diffraction (XRD), x-ray photo electron spectroscopy (XPS), atomic force microscopy, scanning and transmission electron microscopy, nanoindentation, pin-on-disk, and scratch tests. Moreover, the failure mode mechanisms were observed via scanning electron microscopy. The XRD results showed preferential growth in the face-centered cubic (111) crystal structure for [HfN/VN] n multilayered coatings. The best enhancement of the mechanical behavior was obtained when the bilayer period (?) 15 nm ( n = 80), yielding the highest hardness (37 GPa), and elastic modulus (351 GPa). The values for the hardness and elastic modulus were 1.48 and 1.32 times greater than the coating with n = 1, respectively, as well the lowest friction coefficient (~0.15) and the highest critical load (72 N). These results indicated significant enhancements in mechanical, tribological, and adhesion properties, compared to HfN/VN multilayered systems with bilayer period (?) of 1200 nm ( n = 1). This hardness and toughness enhancement in the multilayered coatings could be attributed to the different mechanisms that produce the layer formation with nanometric thickness due to the number of interfaces acting as obstacles for crack deflection and dissipation of crack energy. Due to the emergent characteristics of the synthesized multilayered, the developed adaptive coating could be considered as higher ordered tool machining systems, capable of sustaining extreme operating conditions for industrial applications.

Escobar, C.; Villarreal, M.; Caicedo, J. C.; Aperador, W.; Prieto, P.

2014-11-01

290

Mechanical Properties of Steel Surfaces Coated with HfN/VN Superlattices  

NASA Astrophysics Data System (ADS)

Mechanical and tribological evolution on 4140 steel surfaces coated with hafnium nitride/vanadium nitride [HfN/VN] n multilayer systems deposited in various bilayer periods (?) via magnetron sputtering has been exhaustively studied in this work. The coatings were characterized in terms of structural, chemical, morphological, mechanical, and tribological properties by x-ray diffraction (XRD), x-ray photo electron spectroscopy (XPS), atomic force microscopy, scanning and transmission electron microscopy, nanoindentation, pin-on-disk, and scratch tests. Moreover, the failure mode mechanisms were observed via scanning electron microscopy. The XRD results showed preferential growth in the face-centered cubic (111) crystal structure for [HfN/VN] n multilayered coatings. The best enhancement of the mechanical behavior was obtained when the bilayer period (?) 15 nm (n = 80), yielding the highest hardness (37 GPa), and elastic modulus (351 GPa). The values for the hardness and elastic modulus were 1.48 and 1.32 times greater than the coating with n = 1, respectively, as well the lowest friction coefficient (~0.15) and the highest critical load (72 N). These results indicated significant enhancements in mechanical, tribological, and adhesion properties, compared to HfN/VN multilayered systems with bilayer period (?) of 1200 nm (n = 1). This hardness and toughness enhancement in the multilayered coatings could be attributed to the different mechanisms that produce the layer formation with nanometric thickness due to the number of interfaces acting as obstacles for crack deflection and dissipation of crack energy. Due to the emergent characteristics of the synthesized multilayered, the developed adaptive coating could be considered as higher ordered tool machining systems, capable of sustaining extreme operating conditions for industrial applications.

Escobar, C.; Villarreal, M.; Caicedo, J. C.; Aperador, W.; Prieto, P.

2014-09-01

291

Surface modification of SKD-61 steel by ion implantation technique  

SciTech Connect

The purpose of this study is to investigate how ion implantation affects the surface characteristics and nitrogenizing depth of the thin film by the use of a NEC 9SDH-2 3 MV Pelletron accelerator that implants nitrogen ions into SKD-61 tool steels for surface modification. Nitrogen ions were implanted into the surface layer of materials so that the hardness of modified films could be improved. Also, the nitride film stripping problems of the traditional nitrogenizing treatment could be overcome by a new approach in surface process engineering. As nitrogen ions with high velocity impacted on the surface of the substrate, the ions were absorbed and accumulated on the surface of the substrate. The experiments were performed with two energies (i.e., 1 and 2 MeV) and different doses (i.e., 2.5x10{sup 15}, 7.5x10{sup 15}, and 1.5x10{sup 16} ions/cm{sup 2}). Nitrogen ions were incorporated into the interface and then diffused through the metal to form a nitride layer. Analysis tools included the calculation of stopping and range of ions in matter (SRIM), the detection of a secondary ion mass spectrometry (SIMS), and nanoindentation testing. Through the depth analysis of SIMS, the effects of the ion-implanted SKD-61 steels after heating at 550 deg. C in a vacuum furnace were examined. The nanoindenting results indicate the variation of hardness of SKD-61 steels with the various ion doses. It reaches two to three times the original hardness of SKD-61 steels.

Wen, F. L.; Lo, Y.-L.; Yu, Y.-C. [Department of Mechanical and Computer Aided Engineering, and Graduate Institute of Automation and Mechatronics, St. John's University, Tamsui, Taipei 25135, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China)

2007-07-15

292

Austenitic stainless steel patterning by plasma assisted diffusion treatments  

NASA Astrophysics Data System (ADS)

The new concept of surface texturing or surface patterning on austenitic stainless steel by plasma assisted diffusion treatment is presented in this paper. It allows the creation of uniform micro or nano relief with regularly shaped asperities or depressions. Plasma assisted diffusion treatments are based on the diffusion of nitrogen and/or carbon in a metallic material at moderate to elevated temperatures. Below 420C, a plasma assisted nitriding treatment of austenitic stainless steel produces a phase usually called expanded austenite. Expanded austenite is a metastable nitrogen supersaturated solid solution with a disordered fcc structure and a distorted lattice. The nitrided layer with the expanded austenite is highly enriched in nitrogen (from 10 to 35 at%) and submitted to high compressive residual stresses. From mechanical consideration, it is shown that the only possible deformation occurs in the direction perpendicular to the surface. Such an expansion of the layer from the initial surface of the substrate to the gas phase is used here for surface patterning of stainless steel parts. The surface patterning is performed by using masks (TEM grid) and multi-dipolar plasmas.

Czerwiec, T.; Marcos, G.; Thiriet, T.; Guo, Y.; Belmonte, T.

2009-09-01

293

Structure, properties, and residual stress of 304L stainless steel friction stir welds  

Microsoft Academic Search

Alloy 304L stainless steel sheets, 3.2 mm thick, were joined by friction stir welding at a single welding speed using two different tool rotation rates. The resulting welds were overmatched relative to the base metal. Longitudinal residual stresses (tensile) were near the base metal yield strength.

A. P Reynolds; Wei Tang; T Gnaupel-Herold; H Prask

2003-01-01

294

Inhibition of stainless steel pitting corrosion in acidic medium by 2-mercaptobenzoxazole  

NASA Astrophysics Data System (ADS)

The corrosion behavior of stainless steel samples (304L and 316L) in HCl and H 2SO 4 solution has been studied using potentiodynamic, cyclic voltammogram, EDX and scanning electron microscope (SEM) techniques. The inhibition characteristics of 2-mercaptobenzoxazole (MBO) on 316L stainless steel (316L SS) in HCl solutions were investigated at different temperatures (25, 40, 50 and 60 C). MBO compound has proven to be efficient inhibitors for general and pitting corrosion of 316L SS in HCl solution. The inhibitive property of MBO may be argued to the formation of very low soluble bis-benzoxazolyl disulfide (BBOD) layer and a compact Fe-MBO complex film on the electrode surface. Some samples were examined by scanning electron microscope. The inhibition efficiencies increased with the increasing of MBO concentration but decreased with increasing temperature. The activation energy and thermodynamic parameters were calculated.

Refaey, S. A. M.; Taha, F.; Abd El-Malak, A. M.

2004-09-01

295

Microstructure and Mechanical Behavior of 17-4 Precipitation Hardenable Steel Processed by Selective Laser Melting  

NASA Astrophysics Data System (ADS)

The mechanical behavior and the microstructural evolution of 17-4 precipitation hardenable (PH) stainless steel processed using selective laser melting have been studied. Test coupons were produced from 17-4 PH stainless steel powder in argon and nitrogen atmospheres. Characterization studies were carried out using mechanical testing, optical microscopy, scanning electron microscopy, and x-ray diffraction. The results show that post-process heat treatment is required to obtain typically desired tensile properties. Columnar grains of smaller diameters (<2 m) emerged within the melt pool with a mixture of martensite and retained austenite phases. It was found that the phase content of the samples is greatly influenced by the powder chemistry, processing environment, and grain diameter.

Rafi, H. Khalid; Pal, Deepankar; Patil, Nachiket; Starr, Thomas L.; Stucker, Brent E.

2014-12-01

296

Microstructure and wear properties of Fe-VC-Cr{sub 7}C{sub 3} composite coating on surface of cast steel  

SciTech Connect

An Fe-VC-Cr{sub 7}C{sub 3} composite coating on the surface of cast steel was produced by a novel metal-coated casting technique. The microstructure and wear properties of the product were studied by means of X-ray diffraction, electron beam probe, scanning electron microscopy, and wear testing. The results show that the composite coating consisted of VC and Cr{sub 7}C{sub 3} as the reinforcing phases and {alpha}-Fe as the matrix. The composite coating was metallurgically bonded to the cast steel substrate. The quantity of VC and Cr{sub 7}C{sub 3} carbides decreased gradually from the top surface of the composite coating to the cast steel substrate. The Fe-VC-Cr{sub 7}C{sub 3} composite coating displayed excellent wear-resistance under dry sliding wear test conditions.

Cheng Fengjun [School of Manufacturing Science and Engineering, Sichuan University, Sichuan Chengdu 610065 (China)], E-mail: insephse@163.com; Wang Yisan; Yang Tinggui [School of Manufacturing Science and Engineering, Sichuan University, Sichuan Chengdu 610065 (China)

2008-04-15

297

Effect of hydrogen on tensile properties of martenistic steels for fusion application  

NASA Astrophysics Data System (ADS)

The present work is aimed at giving a contribution to the characterisation of hydrogen embrittlement (HE) resistance of two martensitic steels, i.e. the modified F 82 H and the MANET. The study is based on tensile low strain rate tests, conducted on notched cylindrical specimens which were previously charged with hydrogen. In the case of modified F 82 H steel, two different heat treatments were considered, i.e. the as-received (AR) and the aged condition. The results of the tests indicated that the analysed steels show a noticeable reduction of the area reduction coefficient ( Z%), even for rather low global hydrogen content. As an example, 1-2 wppm are sufficient to lower the Z% of mod. F 82 H to 14-18%, from the 35-40% value typical of the virgin material. In the paper, these results are discussed with the aid of microstructural investigations and SEM analysis which allowed to characterise the microstructural properties of the materials.

Beghini, M.; Benamati, G.; Bertini, L.; Valentini, R.

1998-10-01

298

The effect of boron addition on the tensile properties of control-rolled and normalized C-Mn steels  

Microsoft Academic Search

Control-rolled and normalized C-Mn steels with and without boron alloying at two finish rolling temperatures of 800 C and 1000C were studied with respect to their tensile properties in order to investigate the role of boron in enhancing the strength of these materials. It was found that in boron steels ultimate tensile strength increased and impact transition temperature decreased owing

M. I. Haq; Nazma Ikram

1993-01-01

299

Equal-channel angular sheet extrusion of interstitial-free (IF) steel: Microstructural evolution and mechanical properties  

Microsoft Academic Search

Interstitial-free steel (IF-steel) sheets were processed at room temperature using a continuous severe plastic deformation (SPD) technique called equal-channel angular sheet extrusion (ECASE). After processing, the microstructural evolution and mechanical properties have been systematically investigated. To be able to directly compare the results with those from the same material processed using discontinuous equal channel angular extrusion, the sheets were ECASE

O. Saray; G. Purcek; I. Karaman; T. Neindorf; H. J. Maier

2011-01-01

300

Influence of tempering temperature on the structure and properties of 65G steel after low-temperature thermomechanical working  

Microsoft Academic Search

The crystalline structure changes occurring during low-temperature thermomechanical treatment are responsible for the strength and plasticity of the material [i]. A correlation is observed between the changes in the fine structure of the steels and their mechanical properties, wear resistance, and contact fatigue in a corrosive-abrasive medium. Each steel has its own optimum degree of deformation in low-temperature thermomechanical working

I. I. Kozyrskii; A. S. Opal'chuk; R. A. Khrunik; K. B. Katsov; I. V. Kokotailo; A. E. Semenovskii

1985-01-01

301

Evolution of the structure and properties of silicon steels in the austenite-bainite phase transition  

NASA Astrophysics Data System (ADS)

The specific features of the structure of low-alloy silicon steels have been studied after the phase transition in the temperature range of the bainite transformation. It has been shown that the bainite transformation exhibits a pronounced two-stage character. At the first stage, the completely carbide-free bainite is formed, which contains up to 45% of residual austenite that is stable during deep cooling. The mechanical properties are studied as functions of the morphology and the carbon inhomogeneity of phases formed during the isothermal transformation in the bainite region.

Kaletin, A. Yu.; Kaletina, Yu. V.

2015-01-01

302

Variation in Mechanical Properties and Heterogeneity in Microstructure of High-Strength Ferritic Steel During Mill Trial  

NASA Astrophysics Data System (ADS)

HS600 and HS800 are two new generation, high-strength advanced ferritic steels that find widespread application in automobiles. During commercial production of the same grades with different thicknesses, it has been found that mechanical properties like tensile strength and stretchability varied widely and became inconsistent. In the current endeavor, two different thicknesses have been chosen from a mill trial sample of HS600 and HS800. An in-depth structural characterization was carried out for all four alloys to explain the variation in their respective mechanical and shear punch properties. The carbon content was smaller and Ti + Mo quantity was higher in case of HS800 with respect to HS600. The microstructure of both steels consisted of the dispersion of (Ti,Mo)C in a ferrite matrix. The grain size of HS800 was little larger than HS600 due to an increased coiling temperature (CT) of the former in comparison to the latter. It was found that in case of same grade of steel with a different thickness, a variation in microstructure occurred due to change in strain, CT, and cooling rate. The strength and stretch formability of these two alloys were predominantly governed by a microalloyed carbide. In this respect, carbides with a size range above 5 nm were responsible for loosing coherency with ferrite matrix. In case of HS600, both ?5 and >5-nm size (Ti,Mo)C precipitates shared a nearly equal fraction of microalloyed precipitates. However, for HS800, >5-nm size (Ti,Mo)C carbide was substantially higher than ?5-nm size alloy carbides. The ultimate tensile strength and yield strength of HS800 was superior to that of HS600 owing to a higher quantity of microalloyed carbide with a decreased column width and interparticle distance. A higher degree of in-coherency of HS800 made the alloy prone to crack formation with low stretchability.

Ghosh, M.; Barat, K.; Das, S. K.; Ravi Kumar, B.; Pramanick, A. K.; Chakraborty, J.; Das, G.; Hadas, S.; Bharathy, S.; Ray, S. K.

2014-06-01

303

Microstructure and Mechanical Properties of a Low-Carbon Mn-Si Multiphase Steel Based on Dynamic Transformation of Undercooled Austenite  

NASA Astrophysics Data System (ADS)

The microstructure evolution of 0.20C-2.00Mn-2.00Si steel treated by the thermomechanical process to manufacture hot-rolled, transformation-induced plasticity (TRIP) steel based on dynamic transformation of undercooled austenite was investigated using a Gleeble 1500 (Dynamic Systems, Inc., Poestenkill, NY) hot simulation test machine in combination with light microscope (LM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The mechanical properties of this steel with different multiphase microstructures were also analyzed using room-temperature tensile tests. The results indicated that the multi-phase microstructures consisting of fine-grained ferrite with a size of 1-3 ?m, bainite packets, and retained austenite and martensite were formed for the used steel by a thermo-mechanical process involving dynamic transformation of undercooled austenite, controlled cooling, isothermal bainite treatment and water-quenching. With the increase in the strain of hot deformation of undercooled austenite, the fraction of ferrite increased, that of bainite decreased, and that of martensite increased. At the same time, the fraction of retained austenite (RA), as well as the carbon content of RA, first increased and then decreased. For the used steel treated by such process, the tensile strength is about 1200 MPa with a total elongation of about 20 pct, and the product of tensile strength and total elongation can be up to 25,000 MPa pct.

Li, Longfei; Zhang, Xiaojing; Yang, Wangyue; Sun, Zuqing

2013-09-01

304

The effect of long-term aging on the impact properties of modified 9Cr-1Mo steel  

SciTech Connect

The Charpy impact and room-temperature tensile properties of two heats of modified 9Cr-1Mo steel have been examined after aging at temperatures from 482 to 704C for times up to 75,000 h. In general, aging at lower temperatures (482, 538, or 593C) resulted in little change in the room-temperature tensile properties, but rapid increases in the transition temperature, with the greatest increase for an aging time of 25,000 h. The upper-shelf energy level decreased, reaching a minimum at 25,000 h, followed by recovery at 50,000-h aging. At higher aging temperatures (649 and 704C) there was little change in the transition temperatures, but significant softening at room temperature, and large increases in the upper-shelf energy.

Alexander, D.J.; Maziasz, P.J.; Brinkman, C.R.

1992-12-31

305

Elevated-temperature tensile and creep properties of several ferritic stainless steels  

NASA Technical Reports Server (NTRS)

The elevated-temperature mechanical properties of several ferritic stainless steels were determined. The alloys evaluated included Armco 18SR, GE 1541, and NASA-18T-A. Tensile and creep strength properties at 1073 and 1273 K and residual room temperature tensile properties after creep testing were measured. In addition, 1273 K tensile and creep tests and residual property testing were conducted with Armco 18SR and GE 1541 which were exposed for 200 hours to a severe oxidizing environment in automotive thermal reactors. Aside from the residual tensile properties for Armco 18SR, prior exposure did not affect the mechanical properties of either alloy. The 1273 K creep strength parallel to the sheet-rolling direction was similar for all three alloys. At 1073 K, NASA-18T-A had better creep strength than either Armco 18SR or GE 1541. NASA-18T-A possesses better residual properties after creep testing than either Armco 18SR or Ge 1541.

Whittenberger, J. D.

1977-01-01

306

Exploration of surface hydrophilic properties on AISI 304 stainless steel and silicon wafer against aging after atmospheric pressure plasma treatment  

NASA Astrophysics Data System (ADS)

The aim of this work is to seek the enhanced surface hydrophilic properties on AISI 304 stainless steel and silicon wafer after atmospheric pressure plasma treatment using a specifically designed atmospheric pressure plasma jet. The aging tendency of surface hydrophilic property under air is highlighted. It is concluded that both of the silicon wafer and stainless steel treated with plasma generated from supply gas of argon 15 slm mixed with oxygen 40 sccm shows a better tendency on remaining high water contact angle as compared to that with pure argon and nitrogen addition. Additional peaks of O I (777, 844 nm), O II (408 nm) are detected by optical emission spectroscope indicating the presence of the oxygen radicals and ionic species, which interact with surfaces and thus contribute to low water contact angle (WCA) surfaces. Moreover, the result acquired from X-ray photoelectron spectroscopy (XPS) indicates that the increase in the oxygen-related bonding exhibits a better contribution on remaining high surface energy over a period of time.

Chuang, Shang-I.; Duh, Jenq-Gong

2014-11-01

307

[Quantitative analysis of Mn and Si of alloy steels by laser-induced breakdown spectroscopy].  

PubMed

The concentration of Mn and Si in different kinds of steels was determined by laser-induced breakdown spectroscopy (LIBS). The multivariate quadratic nonlinear function was adopted for calibration. Samples including common alloy steels, stainless steels and carbon tool steels were analyzed. The matrix effect was serious because of large difference in compositions of different kinds of steels and strong line overlaps in steel spectra. Therefore, the common calibration methods that only use one analytical line to calibrate the complex chemical compositions of alloy steels will lose much information. The multivariate calibration methods, however, can utilize more information of spectra, successfully reduce the matrix effect and improve the measurement repeatability and accuracy of LIBS. Compared with the common calibration method based on one analytical line, the relative standard deviation was reduced from above 20% to below 10%, and the accuracy was increased by more than 5 times for Mn and more than 6 times for Si. PMID:21322202

Sun, Lan-Xiang; Yu, Hai-Bin; Xin, Yong; Cong, Zhi-Bo

2010-12-01

308

Microstructures and Mechanical Properties of a New As-Hot-Rolled High-Strength DP Steel Subjected to Different Cooling Schedules  

NASA Astrophysics Data System (ADS)

Controlled rolling followed by accelerated cooling was carried out in-house to study the microstructure and mechanical properties of a low carbon dual-phase steel. The objective of the study described here was to explore the effect of cooling schedule, such as air cooling temperature and coiling temperature, on the final microstructure and mechanical properties of dual-phase steels. Furthermore, the precipitation behavior and yield ratio are discussed. The study demonstrates that it is possible to obtain tensile strength and elongation of 780 MPa and 22 pct, respectively, at the two cooling schedules investigated. The microstructure consists of 90 pct ferrite and 10 pct martensite when subjected to moderate air cooling and low temperature coiling, such that the yield ratio is a low 0.69. The microstructure consists of 75 pct ferrite and 25 pct granular bainite with a high yield ratio of 0.84 when the steel is directly cooled to the coiling temperature. Compared to the conventional dual-phase steels, the high yield strength is attributed to precipitation hardening induced by nanoscale TiC particles and solid solution strengthening by high Si content. The interphase precipitates form at a suitable ledge mobility, and the row spacing changes with the rate of ferrite transformation. There are different orientations of the rows in the same grain because of the different growth directions of the ferrite grain boundaries, and the interface of the two colonies is devoid of precipitates because of the competitive mechanisms of the two orientations.

Hu, Jun; Du, Lin-Xiu; Wang, Jian-Jun; Gao, Cai-Ru; Yang, Tong-Zi; Wang, An-Yang; Misra, R. D. K.

2013-11-01

309

Monitoring the microstructure of pearlitic steels by magnetoacoustic emission  

SciTech Connect

Magnetoacoustic emission (MAE) and Barkhausen emission (BE) measurements have been made on hypereutectoid steel samples heat treated to produce completely pearlitic microstructures with various interlamellar spacings. Both the peak height ratio of the MAE profile and the amplitude of the BE profile were found to increase with increasing interlamellar spacing. These results can be explained in the context of the domain structure and the domain wall processes observed by Lorentz microscopy. The correlation of the spacing with the shape of the MAE and BE profiles shows that both techniques are useful for monitoring the pearlite interlamellar spacing.{copyright} {ital 1997 American Institute of Physics.}

Lo, C.C.; Jakubovics, J.P. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)] [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Scruby, C.B. [AEA Technology plc, National NDT Centre, Culham, Abingdon, Oxon OX14 3DB (United Kingdom)] [AEA Technology plc, National NDT Centre, Culham, Abingdon, Oxon OX14 3DB (United Kingdom)

1997-04-01

310

Microstructure and Properties of Selective Laser Melted High Hardness Tool Steel  

NASA Astrophysics Data System (ADS)

A secondary hardening tool steel material X110CrMoVAl 8-2 was successfully processed by selective laser melting (SLM), producing defect free samples of high density. The microstructure appeared irregular after SLM, which was attributed to locally different temper states in consequence of the SLM process pattern. By a subsequent heat treatment, a homogeneous microstructure with ultrafine carbide precipitations and a very high resulting hardness of 765 HV were achieved. The hardness came very close to that of the same material processed by spray forming and forging, whilst the SLM microstructure was significantly finer. Therefore this tool steel material was considered as highly promising for SLM manufacturing of tools, e.g. for micro tooling applications.

Feuerhahn, F.; Schulz, A.; Seefeld, T.; Vollertsen, F.

311

[Electrochemical properties of biocompatible material hardness modifications on titanium and steel under mechanical loads].  

PubMed

Friction corrosion may appear between different implant components or between implant and hard tissue. The sliding micro movements induce fretting wear corrosion and have been recently reported as a cause of joint prostheses failure. A surface coating is desirable, that retains the mechanical properties of the substrate, offers good biocompatibility and improves the fretting corrosion resistance. In this study it could be demonstrated that tantalum and niobium coatings fulfill the requirements. On titanium substrates the coating decreases the abrasion against PMMA, an orthopedic relevant material. Furthermore, in the case of medical steel substrates the biocompatibility and the corrosion properties are improved. The better abrasion-resistance is minimizing the release of allergological critical particles like nickel and chromium. PMID:15884706

Braun, W; Walter, U; Holbein, R; Thull, R

2005-04-01

312

Structure-property relationships of an A36 steel alloy under dynamic loading conditions  

NASA Astrophysics Data System (ADS)

Structure-property quantification of an A36 steel alloy was the focus of this study in order to calibrate and validate a plasticity-damage model. The microstructural parameters included grain size, particle size, particle number density, particle nearest neighbor distances, and percent of ferrite and pearlite. The mechanical property data focused on stress-strain behavior under different applied strain rates (0.001/s, 0.1/s, and 1000/s), different temperatures (293 K and 573 K), and different stress states (compression, tension, and torsion). Notch tension tests were also conducted to validate the plasticity-damage model. Also, failure of an A36 I-beam was examined in cyclic loads, and the crack growth rates were quantified in terms of fatigue striation data. Dynamic strain aging was observed in the stress-strain behavior giving rise to an important point that there exists a critical temperature for such behavior.

Mayatt, Adam J.

313

A mechanical property and stress corrosion evaluation of 431 stainless steel alloy  

NASA Technical Reports Server (NTRS)

The mechanical properties of type 431 stainless steel in two conditions: annealed bar and hardened and tempered bar are presented. Test specimens, manufactured from approximately 1.0 inch (2.54 cm) diameter bar stock, were tested at temperatures of 80 F (+26.7 C), 0 F (-17.8 C), -100 F (-73 C), and -200 F (-129 C). The test data indicated excellent tensile strength, notched/unnotched tensile ratio, ductility, shear, and impact properties at all testing temperatures. Results of the alternate immersion stress corrosion tests on stressed and unstressed longitudinal tensile specimens 0.1250 inch (0.3175 cm) diameter and transverse C-ring specimens, machined from 1.0 inch (2.54 cm) diameter bar stock, indicated that the material is not susceptible to stress corrosion cracking when tested in a 3.5 percent NaCl solution for 180 days.

Montano, J. W.

1973-01-01

314

Effect of Boron on Microstructure and Mechanical Properties of Hot-Rolled Nb-ADDED Hsla H-Section Steel  

NASA Astrophysics Data System (ADS)

In our research, boron was added into the Nb-added high strength low alloy (HSLA) H-section steels. The contents of boron added were 4ppm, 8ppm and 11ppm, respectively. The mechanical properties of H-section steels with/without boron were examined by using uniaxial tensile test and Charpy impact test (V-notch). The morphologies of the microstructure and the fracture surfaces of the impact specimens were observed by metalloscope, stereomicroscope and electron probe. The experimental results indicate that boron gives a significant increase in impact toughness, especially in low temperature impact toughness, though it leads to an unremarkable increase in strength and plasticity. For instance, the absorbed energy at -40C reaches up to 126J from 15J by 8ppm boron addition, and the ductile-brittle transition temperature declines by 20C. It is shown that boron has a beneficial effect on grain refinement. The fracture mechanism is transited from cleavage fracture to dimple fracture due to boron addition.

Wang, Zuocheng; Cui, Guotao; Sun, Tao; Guo, Weimin; Zhao, Xiuling; Gao, Junqing; Dong, Changxing

315

The Hall-Petch Relationship in Interstitial-Free Steel Processed by Equal Channel Angular Extrusion  

NASA Astrophysics Data System (ADS)

The Hall-Petch relationship was studied in interstitial-free steel subjected to ? = 90 Equal Channel Angular Extrusion for up to N = 8 passes via route BC processing. The composite equation indicates that although low-angle grain boundaries provide the maximum strengthening up to N = 8 passes, the contribution from high-angle boundaries also increases with greater pass number. Alternatively, the evolution of boundary misorientation in as-ECAE microstructures and its effect on mechanical properties up to N = 3 passes is also understood by using a misorientation scaling factor within the original Hall-Petch equation.

Gazder, Azdiar A.; Davies, Christopher H. J.; Pereloma, Elena V.

316

Study of passive films formed on AISI 304 stainless steel by impedance measurements and photoelectrochemistry  

SciTech Connect

Moss-Schottky plots and photoelectrochemical measurements were made on films formed at different potentials on AISI 304 stainless steel in a borate/boric acid solution, pH 9.2. The results allowed the determination of the semiconductive properties and band structure of the films, which account for the existence of two kinds of films depending on the formation potential. For potentials below 0 V (SCE), the results point out for a film with an inverse spinel structure constituted by Cr-substituted magnetite with two donor levels. Above 0 V only one donor level is detected, which should be Fe{sup 2 +} on tetrahedral sites.

Simoes, A.M.P.; Ferreiro, M.G.S. (Dept. de Engenharia Quimica, Instituto Superior Tecnico, 1096 Lisboa Codex (PT)); Rondot, B.; Belo, M. (Centre National de la Recherche Scientifique, 94 - Vitry-sur-Seine (France). Centre d'Etudes de Chimie Metallurgique)

1990-01-01

317

Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties  

SciTech Connect

Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)

1997-04-01

318

A Micro-Alloyed Ferritic Steel Strengthened by Nanoscale Precipitates  

SciTech Connect

A high strength ferritic steel with finely dispersive precipitates was investigated to reveal the fundamental strengthening mechanisms. Using energy dispersive X-ray spectroscopy (EDXS) and transmission electron microscope (TEM), fine carbides with an average diameter of 10 nm were observed in the ferrite matrix of the 0.08%Ti steel, and some cubic M23C6 precipitates were also observed at the grain boundaries and the interior of grains. The dual precipitate structure of finely dispersive TiC precipitates in the matrix and coarse M23C6 at grain boundaries provides combined matrix and grain boundary strengthening. The calculated amount of precipitation strengthening by the carbides was approximately 450 ~ 630 MPa, depending on the average size of nanoscale precipitates. This value is two or three times higher than that of conventional Ti-bearing high strength hot-rolled sheet steels. Dislocation densities increased from 3.421013 m-2 to 1.69 1014 m-2, espectively, with increasing tensile strain from 5.5% to 22%. The effect of the particle size, particle distribution and intrinsic particle strength have been investigated through dislocation dynamics (DD) simulations and the relationship for resolved shear stress for single crystal under this condition has been presented using simulation data. The results show that the finely dispersive precipitates can strengthen the material by pinning the dislocations up to a certain shear stress and retarding the recovery as well as annihilation of dislocations. The DD results also show that strengthening is not only a function of the density of the nano-scale precipitates but also of their size.

Shen, Yongfeng; Wang, Chong M.; Sun, Xin

2011-10-25

319

High heat loading properties of vacuum plasma spray tungsten coatings on reduced activation ferritic/martensitic steel  

NASA Astrophysics Data System (ADS)

High density W coatings on reduced activation ferritic martensitic steel (RAF/M) have been produced by Vacuum Plasma Spraying technique (VPS) and heat flux experiments on them have been carried out to evaluate their possibility as a plasma-facing armor in a fusion device. In addition, quantitative analyses of temperature profile and thermal stress have been carried out using the finite element analysis (FEA) to evaluate its thermal properties. No cracks or exfoliation has been formed by steady state and cyclic heat loading experiments under heat loading at 700 C of surface temperature. In addition, stress distribution and maximum stress between interface of VPS-W and RAF/M have been obtained by FEA. On the other hand, exfoliation has occurred at interlayer of VPS-W coatings near the interface between VPS-W and RAF/M at 1300 C of surface temperature by cyclic heat loading.

Tokunaga, K.; Hotta, T.; Araki, K.; Miyamoto, Y.; Fujiwara, T.; Hasegawa, M.; Nakamura, K.; Ezato, K.; Suzuki, S.; Enoeda, M.; Akiba, M.; Nagasaka, T.; Kasada, R.; Kimura, A.

2013-07-01

320

Decontamination of steel by melt refining: A literature review  

SciTech Connect

It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs.

Ozturk, B.; Fruehan, R.J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States)

1994-12-31

321

Influence of material properties and laboratory test conditions on SOHIC at line pipe carbon steels  

SciTech Connect

Stress oriented hydrogen induced cracking (SOHIC) is a cracking mechanism typical for of low strength line pipe carbon steels. The paper reports on investigations to find experimental conditions suitable to study medium and materials related parameters influencing the SOHIC susceptibility of steel. It was not possible to identify medium conditions that produce SOHIC at stressed, unnotched samples under 1 bar (0.1 MPa) hydrogen sulfide. Increasing the test severity by filming 4-point bend or tensile specimens with a low concentrated aqueous salt solution instead of submerging them in this solution yielded appropriate SOHIC test conditions, the severity of which can be easily modified with the H{sub 2}S partial pressure. It was exemplified that the concentration of nonmetallic inclusions, cold deformation (e.g. specimens preparation by flattening of curved coupons) and banded microstructures significantly contribute to the SOHIC susceptibility. Uniaxial tensile testing can evaluate critical stress levels for SOHIC development under given hydrogen sulfide partial pressures.

Siegmund, G.; Bruckhoff, W. [BEB Erdgas und Erdol GmbH, Hannover (Germany); Schmitt, G.; Pankoke, U.; Sadlowsky, B. [Iserlohn Univ. of Applied Sciences (Germany). Lab. for Corrosion Protection

1998-12-31

322

Soft magnetic composites manufactured by warm co-extrusion of bulk metallic glass and steel powders  

SciTech Connect

Soft magnetic composites of Fe-based bulk metallic glass and low-alloy steel have been manufactured by warm co-extrusion of precursor powders at temperatures within the supercooled liquid region of the glass. Composites were manufactured with amorphous volume fractions of 75%, 67%, and 100%. Full consolidation of the constituent powders was observed with the bulk metallic glass remaining substantially amorphous. The composite electrical resistivity was observed to be anisotropic with a resistivity of 79 {mu}{Omega} cm measured transverse to the extrusion axis in a sample with 75% amorphous volume fraction. A 0-3 connectivity pattern with the low-resistivity steel phase embedded in a 3-dimensionally connected high-resistivity bulk metallic glass phase was observed with scanning electron microscopy. This confirms that the flow characteristics of the bulk metallic glass and the steel powders were comparable during extrusion at these temperatures. The saturation magnetization of 1.3 T was consistent with the volume weighted average of the saturation magnetization of the two phases. A relatively high quasistatic coercivity of 8 Oe was measured and is likely due to slight crystallization of the bulk metallic glass as well as domain wall pinning at prior particle boundaries. Careful control of the thermal environment during the extrusion process is required to minimize glass crystallization and achieve the desired balance of magnetic and electrical properties.

Johnson, Francis; Raber, Thomas R.; Zabala, Robert J.; Buresh, Steve J.; Tanico, Brian [GE Global Research, Ceramic and Metallurgy Technologies, One Research Circle, Niskayuna, New York 12309 (United States)

2013-05-07

323

Soft magnetic composites manufactured by warm co-extrusion of bulk metallic glass and steel powders  

NASA Astrophysics Data System (ADS)

Soft magnetic composites of Fe-based bulk metallic glass and low-alloy steel have been manufactured by warm co-extrusion of precursor powders at temperatures within the supercooled liquid region of the glass. Composites were manufactured with amorphous volume fractions of 75%, 67%, and 100%. Full consolidation of the constituent powders was observed with the bulk metallic glass remaining substantially amorphous. The composite electrical resistivity was observed to be anisotropic with a resistivity of 79 ?? cm measured transverse to the extrusion axis in a sample with 75% amorphous volume fraction. A 0-3 connectivity pattern with the low-resistivity steel phase embedded in a 3-dimensionally connected high-resistivity bulk metallic glass phase was observed with scanning electron microscopy. This confirms that the flow characteristics of the bulk metallic glass and the steel powders were comparable during extrusion at these temperatures. The saturation magnetization of 1.3 T was consistent with the volume weighted average of the saturation magnetization of the two phases. A relatively high quasistatic coercivity of 8 Oe was measured and is likely due to slight crystallization of the bulk metallic glass as well as domain wall pinning at prior particle boundaries. Careful control of the thermal environment during the extrusion process is required to minimize glass crystallization and achieve the desired balance of magnetic and electrical properties.

Johnson, Francis; Raber, Thomas R.; Zabala, Robert J.; Buresh, Steve J.; Tanico, Brian

2013-05-01

324

Precipitation Behavior and Mechanical Properties of Ti-Mo Medium-Carbon Steel During Austenite to Bainite Transformation  

NASA Astrophysics Data System (ADS)

The precipitation behavior and evolution of mechanical properties of Ti-Mo-bearing microalloyed medium-carbon steel during austenite to bainite transformation were studied, and two different cooling rates including ultrafast cooling (~80 C/s) and accelerated cooling (~15 C/s) during transformation were also investigated. The results suggest that Ti-Mo-bearing medium-carbon steel yield finer microstructure and nano-precipitates during austenite to bainite transformation during both ultrafast cooling and accelerated cooling processes. Yield strength and tensile strength obtained by ultrafast cooling process were higher than the accelerated cooling process, while the elongation was slightly reduced. Microstructural characterization indicated that grain refinement and precipitation hardening were the primary reasons for the increase in strength. Ultrafast cooling increased the density of dislocations and refined the grain size. Average size of precipitates containing Ti and Mo was 3-6 nm by ultrafast cooling process, while average precipitate size obtained by accelerated cooling process was 6-9 nm.

Deng, Xiangtao; Wang, Zhaodong; Misra, R. D. K.; Han, Jie; Wang, Guodong

2014-12-01

325

Utilization of steel, pulp and paper industry solid residues in forest soil amendment: relevant physicochemical properties and heavy metal availability.  

PubMed

Industrial residue application to soil was investigated by integrating granulated blast furnace or converter steel slag with residues from the pulp and paper industry in various formulations. Specimen analysis included relevant physicochemical properties, total element concentrations (HCl+HNO3 digestion, USEPA 3051) and chemical speciation of chosen heavy metals (CH3COOH, NH2OHHCl and H2O2+H2O2+CH3COONH4, the BCR method). Produced matrices showed liming effects comparable to commercial ground limestone and included significant quantities of soluble vital nutrients. The use of converter steel slag, however, led to significant increases in the total concentrations of Cr and V. Subsequently, total Cr was attested to occur as Cr(III) by Na2CO3+NaOH digestion followed by IC UV/VIS-PCR (USEPA 3060A). Additionally, 80.6% of the total concentration of Cr (370 mg kg(-1), d.w.) occurred in the residual fraction. However, 46.0% of the total concentration of V (2470 mg kg(-1), d.w.) occurred in the easily reduced fraction indicating potential bioavailability. PMID:21377785

Mkel, Mikko; Watkins, Gary; Pyki, Risto; Nurmesniemi, Hannu; Dahl, Olli

2012-03-15

326

Diffusion bonded transition joints of titanium to stainless steel with improved properties  

Microsoft Academic Search

Diffusion bonding was carried out to produce transition joints between commercially pure titanium (cp Ti) and 304 stainless steel (304 ss) in the temperature range of 800950C, under uniaxial pressure of 3 MPa for 5.4 Ks. The transition joints were evaluated by tensile testing, light microscopy, electron probe micro-analysis and X-ray diffraction. The study indicates that transition joints achieve 76%

M. Ghosh; S. Chatterjee

2003-01-01

327

A Study of Chromo-Boronizing on DIN 1.2714 Steel by Duplex Surface Treatment  

NASA Astrophysics Data System (ADS)

In the current study, the microhardness, layer depth, corrosion properties, and kinetics of chromium boride coatings on DIN 1.2714 hot-worked tool steel have been investigated. Thermodiffusion chromium boride coatings have been carried out for the first time by a duplex salt bath immersion coating by chromizing at 1050C followed by boronizing at 950C, 1000C, and 1050C (chromo-boronizing). The coating layer obtained was hard (2482 HV), compact, and homogeneous. The kinetics of the chromium boride coating followed a parabolic relation ( d 2 = Kt) and the activation energy of the formation of the chromo-boronized layer was calculated as 132 kJ/mol. The corrosion resistance of the coating was evaluated by potentiodynamic polarization in 3.5% NaCl solution. The results showed the degradation of the corrosion properties of the coated samples.

Aghaie-Khafri, M.; Mohamadpour Nazar Abady, M.

2012-06-01

328

Ion-nitriding of the AISI M2 high speed tool steel and comparison of its mechanical properties with nitrided steels  

SciTech Connect

In the past it was shown that plasma diffusion treatment of steels has several advantages over conventional processes such as gas or salt bath nitriding and nitrocarburizing. Plasma diffusion treatment allows close control of the process so that surface layers with defined microstructures and properties can be obtained. The amount of {gamma}{prime} and {epsilon} phase present can be easily controlled. In this paper, variation of surfaces hardness properties of AISI M2 high speed tool speed after ion nitriding treatments were investigated. The mechanical and electro-chemical advantages of the ion nitrided structures were compared with the other methods.

Cimen, O.; Alnipak, B. [Univ. of Istanbul, Avcilar, Istanbul (Turkey)

1995-12-31

329

Influence of thermo-mechanical treatment on the tensile properties of a modified 14Cr-15Ni stainless steel  

NASA Astrophysics Data System (ADS)

The titanium modified 14Cr-15Ni austenitic stainless steel is used as clad and wrapper material for fast breeder nuclear reactor. Thermo-mechanical treatments consisting of solution annealing at two different temperatures of 1273 and 1373 K followed by cold-work and thermal ageing have been imparted to the steel to tailor its microstructure for enhancing strength. Tensile tests have been carried out on the thermo-mechanically treated steel at nominal strain rate of 1.6 10-4 s-1 over a temperature range of 298-1073 K. The yield stress and the ultimate tensile strength of the steel increased with increase in solution treatment temperature and this has been attributed to the fine and higher density of Ti(C,N) precipitate. Tensile flow behaviour of the steel has been analysed using Ludwigson and Voce constitutive equations. The steel heat treated at higher solution temperature exhibited earlier onset of cross slip during tensile deformation. The rate of recovery at higher test temperatures was also influenced by variations in solution heat treatment temperature. In addition, dynamic recrystallization during tensile deformation at higher temperatures was profound for steel solution heat-treated at lower temperature. The differences in flow behaviour and softening mechanisms during tensile testing of the steel after different heat treated conditions have been attributed to the nature of Ti(C,N) precipitation.

Vijayanand, V. D.; Laha, K.; Parameswaran, P.; Nandagopal, M.; Panneer Selvi, S.; Mathew, M. D.

2014-10-01

330

Seismic Rehabilitation of RC Frames by Using Steel Panels  

NASA Astrophysics Data System (ADS)

Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame. To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.

Mowrtage, Waiel

2008-07-01

331

Seismic Rehabilitation of RC Frames by Using Steel Panels  

SciTech Connect

Every major earthquake in Turkey causes a large number of building suffer moderate damage due to poor construction. If a proper and fast retrofit is not applied, the aftershocks, which may sometimes come days or weeks after the main shock, can push a moderately damaged building into a major damage or even total collapse. This paper presents a practical retrofit method for moderately damaged buildings, which increases the seismic performance of the structural system by reducing the displacement demand. Fabricated steel panels are used for the retrofit. They are light-weight, easy to handle, and can be constructed very quickly. Moreover, they are cheap, and do not need formwork or skilled workers. They can be designed to compensate for the stiffness and strength degradation, and to fit easily inside a moderately damaged reinforced concrete frame.To test the concept, a half-scale, single-story 3D reinforced concrete frame specimen was constructed at the shake-table laboratories of the Kandilli Observatory and Earthquake Research Institute of Bogazici University, and subjected to recorded real earthquake base accelerations. The amplitudes of base accelerations were increased until a moderate damage level is reached. Then, the damaged RC frames was retrofitted by means of steel panels and tested under the same earthquake. The seismic performance of the specimen before and after the retrofit was evaluated using FEMA356 standards, and the results were compared in terms of stiffness, strength, and deformability. The results have confirmed effectiveness of the proposed retrofit scheme.

Mowrtage, Waiel [Kandilli Observatory and Earthquake Research Institute of Bogazici University, Earthquake Engineering Department, Istanbul (Turkey)

2008-07-08

332

Microstructure and mechanical property of ferritic-martensitic steel cladding under a 650 C liquid sodium environment  

NASA Astrophysics Data System (ADS)

A study was carried out to investigate the effect of liquid sodium on the microstructural and mechanical property of ferritic-martensitic steel (FMS) used for a Sodium-cooled Fast Reactor (SFR) cladding tube. A quasi-dynamic device characterized by natural circulation was constructed and a compatibility test between FMS and liquid sodium was performed. HT9 (12Cr-1MoWVN) and Gr.92 (9Cr-2WNbVNB) coupons as well as a Gr.92 cladding tube were immersed in the 650 C liquid sodium up to 3095 h and a microstructural observation, a mechanical property evaluation such as nanoindentation, and a ring tension test were also done in this study. The results showed that both HT9 and Gr.92 exhibited macroscopic weight loss behavior where pitting and decarburization took place. Weight loss as well as the decarburization process decreased as the chromium content increased. A compatibility test over the cladding tube revealed that a decrease of the mechanical property caused by the aging process governed the whole mechanical property of the cladding tube.

Kim, Jun Hwan; Kim, Sung Ho

2013-11-01

333

Effect of post-weld heat treatment on the mechanical properties of electron beam welded joints for CLAM steel  

NASA Astrophysics Data System (ADS)

In this paper the microstructure and mechanical properties of electron beam weld (EBW) joints for China low activation martensitic (CLAM) steel, which underwent a series of different post weld heat treatments (PWHTs) were studied. The aim of the study was to identify suitable PWHTs that give a good balance between strength and toughness of the EBW joints. The microstructural analyses were performed by means of optical microscope (OM) and scanning electron microscope (SEM). The mechanical properties were determined via tensile tests and Charpy impact tests. The results showed that the tensile strength of the as-weld joint (i.e. without any PWHT) were close to that of the base metal, but the impact toughness was only 13% of that of the base metal due to the existence of a delta-ferrite microstructure. To achieve a significant improvement in toughness a PWHT needs to be performed. If a one-step PWHT is applied tempering at 760 C for 2 h gives EBW joints with high strength at a still acceptable toughness level. If a two-step PWHT is applied, a process involving quenching at 980 C for 0.5 h followed by tempering at 740 C or 760 C for 2 h gives EBW joints with high strength and toughness properties. Whenever possible a two-step PWHT should be applied in favor of a one-step process, because of higher resulting strength and toughness properties.

Wu, Qingsheng; Zheng, Shuhui; Liu, Shaojun; Li, Chunjing; Huang, Qunying

2013-11-01

334

Microstructure and Mechanical Properties in Hot-Rolled Extra High-Yield-Strength Steel Plates for Offshore Structure and Shipbuilding  

NASA Astrophysics Data System (ADS)

Key parameters for a thermomechanically controlled processing and accelerated cooling process (TMCP-AcC) were determined for integrated mass production to produce extra high-yield-strength microalloyed low carbon SiMnCrNiCu steel plates for offshore structure and bulk shipbuilding. Confocal scanning microscopy was used to make in-situ observations on the austenite grain growth during reheating. A Gleeble 3800 thermomechanical simulator was employed to investigate the flow stress behavior, static recrystallization (SRX) of austenite, and decomposition behavior of the TMCP conditioned austenite during continuous cooling. The Kocks-Mecking model was employed to describe the constitutive behavior, while the Johnson-Mehl-Avrami-Kolmogorov (JMAK) approach was used to predict the SRX kinetics. The effects of hot rolling schedule and AcC on microstructure and properties were investigated by test-scale rolling trials. The bridging between the laboratory observations and the process parameter determination to optimize the mass production was made by integrated industrial production trials on a set of a 5-m heavy plate mill equipped with an accelerated cooling system. Successful production of 60- and 50-mm-thick plates with yield strength in excess of 460 MPa and excellent toughness at low temperature (213 K (-60 C)) in the parent metal and the simulated coarse-grained heat affected zone (CGHAZ) provides a useful integrated database for developing advanced high-strength steel plates via TMCP-AcC.

Liu, Dongsheng; Li, Qingliang; Emi, Toshihiko

2011-05-01

335

Optical properties of ion beam textured metals. [using copper, silicon, aluminum, titanium and stainless steels  

NASA Technical Reports Server (NTRS)

Copper, silicon, aluminum, titanium and 316 stainless steel were textured by 1000 eV xenon ions from an 8 cm diameter electron bombardment ion source. Simultaneously sputter-deposited tantalum was used to facilitate the development of the surface microstructure. Scanning electron microscopy of the ion textured surfaces revealed two types of microstructure. Copper, silicon, and aluminum developed a cone structure with an average peak-to-peak distance ranging from 1 micron for silicon to 6 microns for aluminum. Titanium and 316 stainless steel developed a serpentine ridge structure. The average peak-to-peak distance for both of these materials was 0.5 micron. Spectral reflectance was measured using an integrating sphere and a holraum reflectometer. Total reflectance for air mass 0 and 2, solar absorptance and total emittance normalized for a 425 K black body were calculated from the reflectance measurements.

Hudson, W. R.; Weigand, A. J.; Mirtich, M. J.

1977-01-01

336

Evolution of magnetic properties and crystallographic texture in electrical steel with large plastic deformation  

NASA Astrophysics Data System (ADS)

Deformation leads to a hardening of steel due to an increase in the density of dislocations and a reduction in their mobility, giving rise to a state of elevated residual stresses in the crystal lattice. In the microstructure, one observes an increase in the contribution of crystalline orientations which are unfavorable to the magnetization, as seen, for example, by a decrease in B50, the magnetic flux density at a field of 50 A/cm. The present study was carried out with longitudinal strips of fully processed non-oriented (NO) electrical steel, with deformations up to 70% resulting from cold rolling in the longitudinal direction. With increasing plastic deformation, the value of B50 gradually decreases until it reaches a minimum value, where it remains even for larger deformations. On the other hand, the coercive field Hc continually increases. Magnetometry results and electron backscatter diffraction results are compared and discussed.

Fukuhara, M.; Yonamine, T.; Landgraf, F. J. G.; Missell, F. P.

2011-04-01

337

Properties of friction welds between 9Cr-ODS martensitic and ferritic martensitic steels  

NASA Astrophysics Data System (ADS)

Friction welding of oxide-dispersion-strengthened-steel (ODS) and ferritic-martensitic 11Cr-0.5Mo-2W, V, Nb steel (PNC-FMS) was examined to investigate the feasibility of the welding of this alloy combination. Forge pressure was varied in the welding test to investigate the effect on the soundness of the weld joint. Post-weld heat treatment was necessary for the weld joint because of quench hardening in the heat-affected zone in the as-welded condition. The welds were cross-sectioned and examined to determine their metallurgical structure, hardness and tensile strength. Since the heat treatment produced a softened zone near the weld interface, the furnace-cooling rate was investigated to determine the rate at which the softening did not occur. The weld joints were cold-rolled and the soundness of the weld interface was determined by tensile testing the cold-rolled weld joints.

Uwaba, Tomoyuki; Ukai, Shigeharu; Nakai, Tatsuyoshi; Fujiwara, Masayuki

2007-08-01

338

The effect of mechanical deformation on magnetic properties and MRI artifacts of type 304 and type 316L stainless steel.  

PubMed

The purpose of this study was to evaluate the influence of composition and deformation of biomedical stainless steels on mechanical properties, magnetic properties, and MRI artifacts. Type 304 and Type 316L samples were prepared using standard wire-drawing techniques. Mechanical properties were determined using standard test methods. The amount of ferromagnetic phase present was estimated using a Severn Gage and x-ray diffraction. Magnetic field attraction and artifacts were determined using previously described techniques. The strength of both steels increased significantly with increasing deformation. None of the type 316L wires transformed to the magnetic phase. The amount of magnetic phase in the type 304 wires increased with increasing deformation. There was no magnetic field attraction, and artifacts were minimal for all of type 316L wires and the undeformed type 304 wire. Deflection and artifacts were significant for the deformed type 304 stainless steel. These results provide guidance regarding the use of type 304 and type 316L stainless steels for bioimplants. In this regard, type 316L stainless steel seems to be a more acceptable material with respect to MR compatibility. PMID:9400866

Bendel, L P; Shellock, F G; Steckel, M

1997-01-01

339

Effect of superplastic deformation on the bonding property of 00Cr25Ni7Mo3N duplex stainless steel  

NASA Astrophysics Data System (ADS)

The superplastic deformation diffusion bonding of 00Cr25Ni7Mo3N duplex stainless steel was performed on a hot simulator. The microstructure of the bonding interface was characterized by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The mechanical properties of the specimen were investigated by a shear strength test. The results indicated that the shear strength was improved with the increase of superplastic deformation reduction. When the deformation reduction was up to 50%, the shear strength of the specimen achieved 417 Mpa, approaching to that of the base metal. In addtion, the superplastic diffusion bonding technique was not very sensitive to surface roughness levels. When the surface roughness of the bonding specimen surpassed 0.416 ?m (level G2), the shear strength achieved at least 381 MPa.

Chen, Xiao-hui; Ren, Xue-ping; Xu, Hui; Tong, Jian-guo; Zhang, Hai-yan

2012-04-01

340

Analysis of the effect of shot peening on mechanical properties of steel sheets used as screener sieve materials  

NASA Astrophysics Data System (ADS)

Numerous studies have been performed in an attempt to improve fatigue strength of materials by creating compressive residual stresses in the surface layers as a result of the shot peening process. It was shown that the process is highly effective when dealing with particular parts of the body (detail) needed special attention. In this case, those are parts of screen sieve plate situated near the fixed edge and undergo the largest deformation caused by impact bending and thus need a special treatment. In this paper, the results of experimental tests are presented to analyse the effect of microshot peening on mechanical properties, surface layer characteristics and fatigue strength of steel sheet specimens. The data obtained from our experiments can be used for numerical simulations to design details with improved fatigue resistance.

?led?, M.; Bak, ?.; Stachowicz, F.; Zielecki, W.

2013-07-01

341

Reactor Materials Program - Baseline Material Property Handbook - Mechanical Properties of 1950's Vintage Stainless Steel Weldment Components, Task Number 89-23-A-1  

SciTech Connect

The Process Water System (primary coolant) piping of the nuclear production reactors constructed in the 1950''s at Savannah River Site is comprised primarily of Type 304 stainless steel with Type 308 stainless steel weld filler. A program to measure the mechanical properties of archival PWS piping and weld materials (having approximately six years of service at temperatures between 25 and 100 degrees C) has been completed. The results from the mechanical testing has been synthesized to provide a mechanical properties database for structural analyses of the SRS piping.

Stoner, K.J.

1999-11-05

342

Effect of twice quenching and tempering on the mechanical properties and microstructures of SCRAM steel for fusion application  

NASA Astrophysics Data System (ADS)

The effect of twice quenching and tempering on the mechanical properties and microstructures of SCRAM steel was investigated. The results from tensile tests showed that whether twice quenching and tempering processes(1253 K/0.5 h/W.C(water cool) + 1033 K/2 h/A.C(air cool) + 1233 K/0.5 h/W.C + 1033 K/2 h/A.C named after 2Q&2TI, and 1253 K/0.5 h/W.C + 1033 K/2 h/A.C + 1233 K/0.5 h/W.C + 1013 K/2 h/A.C named after 2Q&2TII)increased strength of steel or not depended largely on the second tempering temperature compared to quenching and tempering process(1253 K/0.5 h/W.C + 1033 K/2 h/A.C named after 1Q&1T). Charpy V-notch impact tests indicated that twice quenching and tempering processes reduced the ductile brittle transition temperature (DBTT). Microstructure inspection revealed that the prior austenitic grain size and martensite lath width were refined after twice quenching and tempering treatments. Precipitate growth was inhibited by a slight decrease of the second tempering temperature from 1033 to 1013 K. The finer average size of precipitates is considered to be the main possible reason for the higher strength and lower DBTT of 2Q&2TII compared with 2Q&2TI.

Xiong, Xuesong; Yang, Feng; Zou, Xingrong; Suo, Jinping

2012-11-01

343

Microstructural Features Controlling Mechanical Properties in Nb-Mo Microalloyed Steels. Part I: Yield Strength  

NASA Astrophysics Data System (ADS)

Low carbon Nb-Mo microalloyed steels show interesting synergies between the "micro"-alloying elements when high strength-high toughness properties are required. Strain accumulation in austenite is enhanced, and therefore grain sizes are refined in the final microstructures. The presence of Mo facilitates the presence of non-polygonal phases, and this constituent modification induces an increment in strength through a substructure formation as well as through an increase in the dislocation density. Regarding fine precipitation and its strengthening effect, the mean size of NbC is reduced in the presence of Mo and their fraction increased, thus enhancing their contribution to yield strength. In this paper, a detailed characterization of the microstructural features of a series of microalloyed steels is described using the electron-backscattered diffraction technique. Mean crystallographic unit sizes, a grain boundary misorientation analysis, and dislocation density measurements are performed. Transmission electron microscopy is carried out to analyze the chemical composition of the precipitates and to estimate their volume fraction. In this first part, the contribution of different strengthening mechanisms to yield strength is evaluated and the calculated value is compared to tensile test results for different coiling temperatures and compositions.

Isasti, Nerea; Jorge-Badiola, Denis; Taheri, Mitra L.; Uranga, Pello

2014-10-01

344

Microstructure and properties of plasma-sprayed steel/carbide composites  

SciTech Connect

The microstructure and properties of plasma-sprayed 316 stainless steel containing TiC and NbC were studied over a range of 0-40 vol/o carbide. The stainless steel in the deposits was fully austenitic. The matrix grain size varied with carbide content, and the grain size within melted carbides (splats) was a function of the carbide type. The extent of carbide melting was related to the total amount of carbide in the powder mixture. Yield stress and ultimate tensile strength increased with increasing carbide contents. For a specific type of powder, increases in yield stress were related to the decrease in the average mean free path between particles as the carbide volume fraction increased. The amount of the increase in yield stress varied with the type of carbide and also with the matrix grain size. The fracture strain increased with decreasing particle size, and enhanced ductility was seen in heat-treated and quenched samples, presumably because of increased compressive residual stresses at the carbide/matrix interface. Fracture in these composites was associated with strain localization and critical intercrack spacings. The critical inter-crack spacing at room temperature and at 760/sup 0/C was a function of the average crack length in the cracker carbides.

Ritter, A.M.

1987-01-01

345

MECHANICAL PROPERTIES AND MICROSTRUCTURAL CHARACTERIZATION OF A MULTILAYERED MULTIPASS FRICTION STIR WELD IN STEEL  

SciTech Connect

Multilayered multipass friction stir welding (MM-FSW) makes it possible to use FSW to fabricate thick-section structures. In this work, MM-FSW was demonstrated on a high strength low alloy steel; ASTM A572 Grade 50. Three steel plates with thicknesses of 0.18", 0.18", 0.24" respectively were stacked and friction stir welded together to form a 0.6" thick welded structure. The welded plate was sectioned into rectangular bars transverse to the weld direction for tensile testing to evaluate mechanical properties. Digital image correlation (DIC) was employed to map the local strain fields during tensile testing. The initial failure was found to occur simultaneously at the bottom and middle layers away from the weld zone. The top layer failed last in the base metal. The failure locations were consistent among different samples tested. Also, Charpy V-notch impact tests were conducted for weld metal, heat affected zone, and the base metal at each layer as a function of temperature. The weld microstructures were characterized using optical and electron microscopy and micro-hardness mapping.

Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Qiao, Dongxiao [ORNL; Wang, Yanli [ORNL; Zhang, Wei [ORNL; Feng, Zhili [ORNL

2013-01-01

346

In Situ Synthesis, Microstructure, and Properties of TiC and (Ti,W)C-Reinforced Fe-Mn-Al Austenitic Steel Matrix Composites  

NASA Astrophysics Data System (ADS)

In situ synthesis, microstructures, and properties of 10 vol.% TiC and (Ti,W)C-reinforced Fe-Mn-Al austenitic steel matrix composites have been reported in this paper. The microstructure of the prepared samples has been characterized by using scanning electron microscopy and X-ray diffraction technique. The abrasion wear resistance and mechanical properties such as hardness and impact energy of both the composites as well as the unreinforced Fe-Mn-Al austenitic steel have been evaluated. The (Ti,W)C-reinforced composite has higher impact energy and slightly lower hardness values compared to that of TiC-reinforced composite. The TiC-reinforced composite exhibits the best abrasive wear resistance of all the materials tested.

Srivastava, Ashok Kumar; Das, Karabi

2012-11-01

347

Fatigue behavior of carbon steel by symmetric bending ultrasonic frequency method  

NASA Astrophysics Data System (ADS)

In order to further broaden the scope of the study on ultrasonic fatigue test and realize a variety of loading, a new experimental method named as symmetric bending ultrasonic fatigue (SBUF) method to determine the fatigue behavior of materials by symmetric bending loading is presented in this paper. A series of SBUF tests of two carbon steels with stress ratio R = -1 were carried out. Fatigue behaviors of the two carbon steels were researched by SBUF tests. The results show that the S-N curves under ultrasonic symmetric bending loading display the characteristic of "continually decreasing type" up to 109 cycles and exhibit no traditional horizontal plateau beyond 106 cycles, when the fatigue cycles is over 109, fatigue failure do occurs; S-N curves under ultrasonic symmetric bending loading can be described with the equation of Basquin. Compared to the S-N curves under the axial ultrasonic symmetric tension-compression loading, the results show that in high-cycle stage (<107cycles), the loading method has a significant effect on fatigue properties, but in ultra-high-cycle stage (>107cycles), the loading method has no significant impact on fatigue properties. An influence coefficient of the loading method is introduced in order to describe the influence of loading method of the ultrasonic fatigue.

Tang, Weiwei; Wang, Hong; Cai, Lixun

2008-11-01

348

Mechanical properties of carbon steel depending on the rate of the dose build-up of nitrogen and argon ions  

NASA Astrophysics Data System (ADS)

The effect of pulsed irradiation with argons and nitrogen ions on the mechanical properties, morphology, and structure of the surface layers of carbon steel St3 (0.2% C, 0.4% Mn, 0.15% Si, and Fe for balance) has been investigated depending on the rate of dose build-up at an average ion current density of 10, 20, and 40 ?A/cm2. It has been established that the fatigue life and microhardness of surface layers increase in the entire studied range of dose build-up rates. This seems to be due to the hardening of the surface layers, which resulted from the generation of radiation defects and the irradiation-dynamic effect of fast ions. The sample irradiated by argon ions at the lowest of the selected dose build-up rates j av = 10 ?A/cm2 withstands the largest number of cycles to failure.

Vorob'ev, V. L.; Bykov, P. V.; Bayankin, V. Ya.; Shushkov, A. A.; Vakhrushev, A. V.

2014-08-01

349

Strengthening of hot-rolled high-carbon steels by copper additions and controlled cooling  

Microsoft Academic Search

It is well-known that copper additions can produce significant improvements in strength levels through an age-hardening reaction in low- carbon steels in the quenched and tempered condition. In the present work the effect of copper additions for a number of different processing treatments, as-rolled, normalized and accelerated cooled, on the mechanical properties of high- carbon experimental steels have been studied.

F. A. Khalid; P. Wang; V. Jerath; D. V. Edmonds

1994-01-01

350

Evolution of magnetic properties of cladding austenitic steel under irradiation in a reactor  

NASA Astrophysics Data System (ADS)

Magnetic properties of samples of austenitic steel ChS-68 cut from the cladding of a fuel element, which was irradiated in a BN-600 fast-neutron reactor to a maximal damage dose of 80 displacements per atom (dpa) at temperatures of 370-587C, have been investigated. It has been established that irradiation with fast neutrons leads to the formation of ferromagnetic microregions, the effective sizes and concentration of which depend on the damage dose. It has been shown that, at damage doses higher than 55 dpa, small spontaneous magnetization and magnetization hysteresis, which are characteristic of the ferromagnetic state, appear in the samples. It is assumed that the ferromagnetic microregions are the nuclei of the ?' phase and the radiation-induced segregation microregions, in which the spacing between the nearest iron atoms exceeds the critical distance that determines the change in the sign of exchange interaction. Arguments in favor of this assumption are presented.

Chukalkin, Yu. G.; Kozlov, A. V.; Evseev, M. V.

2014-03-01

351

Weldability, microstructure and properties of precipitation strenghtened martensitic stainless steels. [Custom 450; PH 13-8 Mo  

Microsoft Academic Search

We have investigated the influence of welding on the mechanical properties and corrosion resistance of two precipitation strengthened martensitic stainless steels: Custom 450 and PH 13-8 Mo. The two alloys exhibited very good weld cracking resistance, although the formation of a low melting NbC eutectic constituent did cause some solidification cracking in Custom 450. The effects of aging temperature on

J. A. Brooks; W. R. Cieslak; W. M. Jr. Garrison

1986-01-01

352

INFLUENCE OF WELDING PROCESSES ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF DISSIMILAR AUSTENITIC-FERRITIC STAINLESS STEEL WELDS  

Microsoft Academic Search

Dissimilar metal welding of austenitic (AISI 304)-ferritic (AISI 430) stainless steel has been taken up to understand the influence of the welding process on microstructure and mechanical properties. Fusion welding processes, namely, gas tungsten arc welding (GTAW), electron beam welding (EBW), and friction welding, have been employed. The GTAW and EBW processes were selected to understand the heat input effects,

G. Madhusudhan Reddy; T. Mohandas; A. Sambasiva Rao; V. V. Satyanarayana

2005-01-01

353

Fatigue Testing of TBC on Structural Steel by Cyclic Bending  

NASA Astrophysics Data System (ADS)

For applications with variable loading, fatigue performance of coated parts is of utmost importance. In this study, fatigue performance of conventional structural steel coated with thermal barrier coating (TBC) was evaluated in cyclic bending mode by "SF-Test" device. Testing was carried out at each stage of the TBC preparation process, i.e., for as-received and grit-blasted substrates, as well as for samples with Ni-based bond-coat and complete TBC: bond-coat with YSZ-based top-coat. Comparison of results obtained for different loading amplitudes supplemented by fractographic analysis enabled identification of dominating failure mechanisms and demonstrated applicability of the high-frequency resonant bending test for evaluation of fatigue resistance alteration at each stage of the TBC deposition process.

Musalek, Radek; Kovarik, Ondrej; Medricky, Jan; Curry, Nicholas; Bjorklund, Stefan; Nylen, Per

2015-01-01

354

Fatigue Testing of TBC on Structural Steel by Cyclic Bending  

NASA Astrophysics Data System (ADS)

For applications with variable loading, fatigue performance of coated parts is of utmost importance. In this study, fatigue performance of conventional structural steel coated with thermal barrier coating (TBC) was evaluated in cyclic bending mode by "SF-Test" device. Testing was carried out at each stage of the TBC preparation process, i.e., for as-received and grit-blasted substrates, as well as for samples with Ni-based bond-coat and complete TBC: bond-coat with YSZ-based top-coat. Comparison of results obtained for different loading amplitudes supplemented by fractographic analysis enabled identification of dominating failure mechanisms and demonstrated applicability of the high-frequency resonant bending test for evaluation of fatigue resistance alteration at each stage of the TBC deposition process.

Musalek, Radek; Kovarik, Ondrej; Medricky, Jan; Curry, Nicholas; Bjorklund, Stefan; Nylen, Per

2014-11-01

355

Effect of pH on Semiconducting Property of Passive Film Formed on Ultra-High-Strength Corrosion-Resistant Steel in Sulfuric Acid Solution  

NASA Astrophysics Data System (ADS)

Because Cr9Ni5MoCo14 is a new ultra-high-strength corrosion-resistant steel, it is important to study its corrosion behavior in sulfuric acid solution, which is used to simulate the aggressive environment. The effect of pH on the electrochemical and semiconducting properties of passive films formed on ultra-high-strength corrosion-resistant steel in sulfuric acid solution was investigated by means of the potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS), Mott-Schottky analysis, and X-ray photoelectron spectroscopy (XPS). The results indicated that Cr9Ni5MoCo14 steel showed a passive state in acid solutions. The corrosion behavior of this Cr9Ni5MoCo14 alloy was influenced by the passive film formed on the surface, including thickness, stability, and partitioning of elements of the passive film. The passive current density decreases with increasing pH, and the corrosion resistance was enhanced by the increasing thickness and depletion of the defects within the passive film. Moreover, an enrichment of chromium (primarily the oxides of Cr) and depletion of iron in the passive film led to improved corrosion resistance. These results can provide a theoretical basis for use of this alloy and further development of ultra-high-strength corrosion-resistant steel in today's society.

Sun, Min; Xiao, Kui; Dong, Chaofang; Li, Xiaogang; Zhong, Ping

2013-10-01

356

Effect of chromium additions on the mechanical and physical properties and microstructure of Fe-Co-Ni-Cr-Mo-C ultra-high strength steel: Part 1  

SciTech Connect

The effect of chromium additions to an Fe-14Co-10Ni-0.1Mo-0.16C (AF1410 based) secondary hardening steel was evaluated by mechanical and physical properties and by microstructural examination. This unique behavior was extended to encompass a large range of aging temperatures and times that may be encountered during commercial thermal treatment and/or welding. In the aging range of 482 to 550 C, an increase in chromium from 2 to 3% in the AF1410 based steel resulted in a substantial strength decrease concomitant with an increase in toughness. This behavior is related to a peak hardening shift, early M{sub 2}C carbide coarsening, and an increase in reverted austenite for the 1 wt% Cr increase. The increased aging kinetics resulting from the 3Cr steel caused a faster dissolution of Fe{sub 3}C and rapid changes in chromium partitioning in the (Mo,Cr){sub 2} carbide resulting in a coherency loss with a corresponding decrease in lattice parameter. The kinetics of the secondary hardening reaction, for the two steels, was determined by resistivity data for changes in aging parameters (time/temperature).

Machmeier, P.M.; Matuszewski, T. [Snap-on Tools, Inc., Kenosha, WI (United States); Jones, R.L. [R and J Consulting, Fort Worth, TX (United States); Ayer, R. [STEM, Woodridge, CT (United States)

1997-06-01

357

NIOBIUM-CLAD 304L STAINLESS STEEL PEMFC BIPOLAR PLATE MATERIAL: TENSILE AND BEND PROPERTIES  

SciTech Connect

Niobium (Nb)-clad 304L stainless steel (SS) is currently under consideration for use as a bipolar plate material in polymer electrolyte membrane fuel cell (PEMFC) stacks. Because metal bipolar plates will likely be formed by stamping, the sheet metal properties of this material were characterized in both the as-rolled and an optimized annealed condition via a series of bend and quasi-static tensile tests. Results from tensile testing demonstrate that annealing significantly softens and thereby improves the ductility of the material. Bend test results indicate that springback is nearly independent of the bend direction relative to rolling direction for both the as-rolled and annealed conditions. In the as-rolled condition, springback is also nearly independent of specimen orientation (i.e. whether the cladding layer is on the inside or outside of the bend). However in the annealed condition, springback does depend on the cladding orientation relative to bending and was found in all cases to be substantially lower than that observed in the as-rolled condition. Microstructural analysis of the specimens indicates that two failure conditions can potentially arise, dependent on the thermomechanical condition of the material. In the as-rolled condition, failure initiates via fracture through the Nb cladding. In the annealed specimens, failure can occur by brittle fracture of an interfacial intermetallic layer that forms during the annealing treatment. This generates a series of crack-induced pores along the interface between the Nb cladding and the SS core, which eventually leads to ductile failure of the Nb cladding via localized necking. However the conditions required for this phenomenon to take place are fairly extreme and can be readily avoided in practice. In general, the results suggest that to achieve acceptable stamping tolerances, the material should be annealed prior to forming and the bipolar plate flow channel pattern should be designed such that extreme levels of strain at the cladding/core interface are avoided to mitigate the potential for partial delamination within the material.

Hong, Sung-tae; Weil, K. Scott

2007-06-01

358

Effect of boron doping on the structural transformations and properties of low manganese steels  

Microsoft Academic Search

1.Doping of temper hardened steels containing 0.150.25% C with boron improves their bulk hardenability. As a result, the strength of boron containing low manganese steels attain the level of boronless steels with high manganese content. At the same time impact toughness and ductility remain practically unchanged.2.In the investigated steels doped with boron, boron containing inclusions may segregate; their composition and

G. Z. Koval'chuk; V. N. Yarmosh

1988-01-01

359

SCC maps for low-alloy steels by SSRT method  

SciTech Connect

Low alloy steels have been used as the pressure boundary component materials of LWR primary coolant systems. So it is very important to clarify the stress corrosion cracking behavior of the alloys. The slow strain rate tensile test(SSRT) was carried out on three heats of heavy-thick low alloy steels in high temperature water containing various levels of dissolved oxygen (DO) at various temperature to investigate the stress corrosion cracking (SCC) behavior. The results obtained are as follows: (1) Rolled steels with high sulfur content have SCC susceptibility in the wide region of temperature-DO concentration combination, even below DO < 0.005 ppm at 473 K. (2) A forged steel with extremely low sulfur content is almost immune to SCC. (3) SCC maps showing SCC region were made for each steel.

Arai, Taku; Mayuzumi, Masami; Ohta, Joji [Electric Power Industry, Komae, Tokyo (Japan). Central Research Inst.

1998-12-31

360

Fabrication of high nitrogen austenitic stainless steels with excellent mechanical and pitting corrosion properties  

Microsoft Academic Search

A series of high nitrogen austenitic stainless steels were successfully developed with a pressurized electroslag remelting furnace. Nitride additives and deoxidizer were packed into the stainless steel pipes, and then the stainless steel pipes were welded on the surface of an electrode with low nitrogen content to prepare a compound electrode. Using Si3N4 as a nitrogen alloying source, the silicon

Hua-bing Li; Zhou-hua Jiang; Yang Cao; Zu-rui Zhang

2009-01-01

361

Effect of oxygen on the mechancial properties and character of fallure of powder steel 40N3M  

Microsoft Academic Search

1.Oxygen in real sprayed and deformed steels (a porosity of less than 1%) lowers the mechanical properties even when its content is approximately 0.01%; this is apparently associated with its presence in the solid solution. A further increase in the oxygen content (to 0.1%) has little effect on the mechanical properties, although the cold-shortness threshold is raised in this case.2.The

T. P. Moskvina; A. P. Gulyaev

1988-01-01

362

Stainless steel in bone surgery.  

PubMed

Today, stainless steel is one of the most frequently used biomaterials for internal fixation devices because of a favorable combination of mechanical properties, corrosion resistance and cost effectiveness when compared to other metallic implant materials. The biocompatibility of implant quality stainless steel has been proven by successful human implantation for decades. Composition, microstructure and tensile properties of stainless steel used for internal fixation is standardized in ISO and ASTM material specifications. Metallurgical requirements are stringent to ensure sufficient corrosion resistance, nonmagnetic response, and satisfactory mechanical properties. Torsional properties of stainless steel screws are different from titanium screws. Stainless steel bone screws are easier to handle because the surgeon can feel the onset of plastic deformation and this provides adequate prewarning to avoid overtorquing the screw. New nickel-free stainless steels have been recently developed primarily to address the issue of nickel sensitivity. These stainless steels also have superior mechanical properties and better corrosion resistance. The Ni-free compositions appear to possess an extraordinary combination of attributes for potential implant applications in the future. PMID:11270076

Disegi, J A; Eschbach, L

2000-12-01

363

Mechanical properties and microstructure of copper alloys and copper alloy-stainless steel laminates for fusion reactor high heat flux applications  

NASA Astrophysics Data System (ADS)

A select group of copper alloys and bonded copper alloy-stainless steel panels are under consideration for heat sink applications in first wall and divertor structures of a planned thermonuclear fusion reactor. Because these materials must retain high strengths and withstand high heat fluxes, their material properties and microstructures must be well understood. Candidate copper alloys include precipitate strengthened CuNiBe and CuCrZr and dispersion strengthened Cu-Alsb2Osb3 (CuAl25). In this study, uniaxial mechanical fatigue tests were conducted on bulk copper alloy materials at temperatures up to 500spC in air and vacuum environments. Based on standardized mechanical properties measurement techniques, a series of tests were also implemented to characterize copper alloy-316L stainless steel joints produced by hot isostatic pressing or by explosive bonding. The correlation between mechanical properties and the microstructure of fatigued copper alloys and the interface of copper alloy-stainless steel laminates was examined. Commercial grades of these alloys were used to maintain a degree of standardization in the materials testing. The commercial alloys used were OMG Americas Glidcop CuAl25 and CuAl15; Brush Wellman Hycon 3HP and Trefimetaux CuNiBe; and Kabelmetal Elbrodur and Trefimetaux CuCrZr. CuAl25 and CuNiBe alloys possessed the best combination of fatigue resistance and microstructural stability. The CuAl25 alloy showed only minimal microstructural changes following fatigue while the CuNiBe alloy consistently exhibited the highest fatigue strength. Transmission electron microscopy observations revealed that small matrix grain sizes and high densities of submicron strengthening phases promoted homogeneous slip deformation in the copper alloys. Thus, highly organized fatigue dislocation structure formation, as commonly found in oxygen-free high conductivity Cu, was inhibited. A solid plate of CuAl25 alloy hot isostatically pressed to a 316L stainless steel plate showed the best overall mechanical properties of the studied bi-metallic bonded panels. Bond properties were nominally inferior to constituent bulk material properties and fracture toughness values, in particular, were quite low for all bonded laminates. Delamination near the copper alloy-stainless steel interface was the dominate failure mode in the bi-metallic panels. The joining processes caused microstructural alterations in the bond interfacial regions including: microporosity, new precipitate formation, existing precipitate morphology changes and interdiffusion of constituent elements.

Leedy, Kevin Daniel

364

Hydrogen effects on stainless steel passive film fracture studied by nanoindentation , L.J. Qiao a,  

E-print Network

Letter Hydrogen effects on stainless steel passive film fracture studied by nanoindentation Y. Yao. Hydrogen absorption a b s t r a c t Hydrogen effects on the fracture stress of passive film formed on 316L stainless steel were studied by nanoindentation. Hydrogen accumulated primarily on the sample surface

Volinsky, Alex A.

365

A laboratory study of mild steel vapour phase corrosion and its inhibition by dicyclohexylamine nitrite  

Microsoft Academic Search

A study was made of the corrosion of mild steel by acetic and formic acid vapours at 65, 75, 85 and 100% relative humidity (RH) and its inhibition by dicyclohexylamine nitrite (DICHAN). Electrochemical and gravimetric techniques were used. The corrosion rate of steel was in the range of ? 10145 mdd and ?1035 mdd for 225 ppm acetic and 300

J. M. Bastidas; E. M. Mora

1998-01-01

366

Kinetics of niobium carbide coating produced on AISI 1040 steel by thermo-reactive deposition technique  

Microsoft Academic Search

There are a lot of technologically interesting characteristics of niobium carbide coating deposited by pack method which is the production of hard, wear-resistant, oxidation and corrosion resistant coating layer on the steel substrates. In the present study, the growth kinetics of niobium carbide layer deposited by thermo-reactive diffusion techniques in a solid medium on steel samples was reported. Niobium carbide

Ugur Sen

2004-01-01

367

Liquid metal embrittlement susceptibility of T91 steel by Lead-Bismuth  

E-print Network

Liquid metal embrittlement susceptibility of T91 steel by Lead-Bismuth T. Auger, G. Lorang CNRS!: Liquid metal embrittlement, martensitic steels, Auger electron spectroscopy (AES), physical vapour state do not provide evidence for Liquid Metal Embrittlement (LME) by eutectic Pb-Bi. In this paper, we

Paris-Sud XI, Université de

368

A COMPARATIVE STUDY OF THE WETTABILITY OF STEEL, CARBON, AND POLYETHYLENE FIBERS BY WATER  

E-print Network

A COMPARATIVE STUDY OF THE WETTABILITY OF STEEL, CARBON, AND POLYETHYLENE FIBERS BY WATER W. Lu, X at Buffalo, Buffalo, NY 14260-4400, USA (Received March 9, 1998; in final form April 10, 1998) ABSTRACT The wettability of fibers by water was found to increase in this order: polyethylene fiber, steel fiber

Chung, Deborah D.L.

369

Evolution of Recrystallization by Changes in Magnetic Hysteresis Loop in a Non-Oriented Electric Steel Cold Rolled  

NASA Astrophysics Data System (ADS)

Non-oriented steels, with low carbon, are widely used in the fabrication of electrical motor nucleus. The performance of these motors is affected by the level of recrystallization. These steels can come from the steel plant in two different conditions: totally processed or semi-processed. The semi-processed steels have a partially deformed structure and are submitted to the final annealing process after reaching the end shape. An adequate annealing heat treatment is important to get an appropriate magnetic property. In the present study, samples of an electric steel, with the composition (0.05 wt% C, 1.28wt% Si, 0.29wt% Mn), cold rolled 50% in thickness, were withdrawn during the industrial heat treatment at temperatures of 575, 580, 600, 620 and 730 C with the objective of evaluating the evolution of recrystalization with temperature. Magnetic properties were measured at room temperature in a vibrating sample magnetometer. Although the changes in magnetic hysteresis loop with temperature are difficult to observe, they have been identified by using pattern classification techniques, such as principal-component analysis and Karhunen-Love expansion. These tools have been applied to vectors which are built from each hysteresis loop, properly renormalized, whose components correspond to amplitude of the loop at given equally spaced values of the renormalized field. The samples have been classified in four sets, namely, set A corresponding to temperatures 575/580, set B corresponding to temperatures 600/620, set C corresponding to the samples without annealing heat treatment, and set D corresponding to recrystallized samples. The results for the classification of the different microstructures have been obtained by using both techniques, and in particular a 100% success rate has been reached by using Karhunen-Love expansion.

da Silva, F. E.; Freitas, F. N. C.; Abreu, H. F. G.; Gonalves, L. L.; Moura, E. P.; Silva, M. R.

2011-06-01

370

Microstructural evolution and mechanical properties of aging high nitrogen austenitic stainless steels  

Microsoft Academic Search

The microstructural evolution of 18Cr18Mn2Mo0.77N high nitrogen austenitic stainless steel in aging treatment was investigated\\u000a by optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results show\\u000a that hexagonal intergranular and cellular Cr2N with a=0.478 nm and c=0.444 nm and body-centered cubic intermetallic ? phase with a=0.892 nm precipitate gradually in the isothermal aging treatment. The

Zhou-Hua Jiang; Zu-Rui Zhang; Hua-Bing Li; Zhen Li; Ma Qi-Feng

2010-01-01

371

Laser gas assisted treatment of AISI H12 tool steel and corrosion properties  

NASA Astrophysics Data System (ADS)

Laser gas assisted treatment of AISI H12 tool steel surface is carried out and the electrochemical response of the laser treated surface is investigated. Morphological and metallurgical changes in the treated layer are examined using a scanning electron microscope, energy dispersive spectroscopy, and X-ray diffraction. Potentiodynamic polarization tests are carried out for untreated and laser treated specimen in 0.2 M NaCl solution at room temperature. It is found that the laser treated AISI H12 workpiece surfaces exhibit higher corrosion resistance as compared to untreated specimen as confirmed by lower corrosion rate, higher pitting potential, and lower passive current density.

Yilbas, B. S.; Toor, Ihsan-ul-Haq; Malik, Jahanzaib; Patel, F.

2014-03-01

372

Simple measurement of electromagnetic properties of steel in the Rayleigh domain  

NASA Astrophysics Data System (ADS)

Hysteretic behavior of steel can be approximately described by Rayleigh model in the range of small excitations, corresponding to reversible motion of the walls of the magnetic domains. The main advantage of this model is that it is described by only two parameters: the initial permeability, and the Rayleigh coefficient, which quantifies the hysteresis. In this paper, an experimental technique for retrieving both parameters is developed, which is based on the well-known alternate current potential drop method (ACPD). This technique consists on the measurement of the potential drop between two contacts along a cylindrical sample, which is driven by a sinusoidal current source, with variable frequency below a few kHz, and a maximum current of 20 A. The current is injected through the ends of the sample, while the measuring contacts are placed near the central section. By means of low-current measurements, the initial magnetic permeability and the electrical conductivity are determined, and then high-current measurements are performed for exciting the hysteretic behavior in the range in which Rayleigh's model is valid. By means of a one-dimensional mathematical model, the non-harmonic potential drop corresponding to each possible Rayleigh parameter is calculated, and the best fit for each sample is found numerically. Comparative results for different steels are presented.

Etcheverry, J. I.; Snchez, G. A.

2013-01-01

373

A Study of Microstructure and Mechanical Properties of Grade 91 Steel A-TIG Weld Joint  

NASA Astrophysics Data System (ADS)

In the present study, A-TIG welding was carried out on grade 91 steel plates of size 220 110 10 mm using the in-house developed activated flux to produce butt-joints. The room-temperature impact toughness of the A-TIG as-welded joint was low due to the presence of untempered martensite matrix despite the low microinclusion density caused by activated flux and also low ?-ferrite (<0.5 %) content. Toughness after postweld heat treatment (PWHT) at 760 C-2 h was 20 J as against the required value of 47 J as per the specification EN: 1557:1997. However, there was a significant improvement in impact toughness after PWHT at 760 C for 3 h. The improvement in toughness was attributed to softening of martensite matrix caused by precipitation of carbides due to tempering reactions. The precipitates are of type M23C6, and they are observed at grain boundary as well as within the grains. The A-TIG-processed grade 91 steel weld joint was found to meet the toughness requirements after PWHT at 760 C-3 h. Observations of fracture surfaces using SEM revealed that the as-welded joint failed by brittle fracture, whereas post-weld heat-treated weld joints failed by decohesive rupture mode.

Arivazhagan, B.; Vasudevan, M.

2013-12-01

374

Mechanical, tribological, and corrosion properties of stainless steel of the austenitic class grade Kh23N18 with additions of chromium carbide  

Microsoft Academic Search

The mechanical, tribological, and corrosion-resistance properties of stainless steel Kh23N18 with additions of 2.5 and 10%\\u000a Cr3C2 are studied. It is established that chromium carbide reduces the ductility properties and in most cases steel strength, but\\u000a there is an increase in hardness and tribological properties with a Cr3C2 content of 10%. There is a slight reduction in corrosion resistance but

S. G. Napara-Volgina; L. N. Orlova; V. K. Kud; Yu. A. Popchenko; A. K. Skuratovskii

1998-01-01

375

Corrosion inhibition of mild steel by plant extract in dilute HCl medium  

Microsoft Academic Search

The inhibition effect of Zenthoxylum alatum plant extract on the corrosion of mild steel in 5% and 15% aqueous hydrochloric acid solution has been investigated by weight loss and electrochemical impedance spectroscopy (EIS). The corrosion inhibition efficiency increases on increasing plant extract concentration till 2400ppm. The effect of temperature on the corrosion behaviour of mild steel in 5% and 15%

L. R. Chauhan; G. Gunasekaran

2007-01-01

376

Transient current generation during wear of high-density polyethylene by a stainless-steel stylus  

E-print Network

Transient current generation during wear of high-density polyethylene by a stainless-steel stylus J force measurements as a stainless-steel stylus is drawn across a high-density polyethylene surface-related features at intervals consistent with the lateral force and current fluctuations. Although average charge

Dickinson, J. Thomas

377

Liquid metal embrittlement of tensile specimens of En19 steel by tin  

Microsoft Academic Search

Liquid metal induced embrittlement (LMIE) of En19 steel was investigated by tensile testing specimens coated with liquid pure tin. Testing was carried out over a range of steel hardnesses and test temperatures, and for each material hardness the temperature above which recovery of the unembrittled tensile behaviour of the specimens occurred was measured. Metallographic examination of each of the specimens

R. E Clegg; D. R. H Jones

2003-01-01

378

Determining the cooling affected volume by adding microcoolers in the steel  

NASA Astrophysics Data System (ADS)

The study presents the calculus of the cooling affected volume by adding a quantity of microcoolers in the liquid steel when it is casted. When directing the crystal germination processes in the casted steel bar, small and uniform seeds are resulting who lead to short solidifying and homogenization times and high values of the mechanical characteristics of the blanks obtained from these bars.

Pascu, Liviu; Stoica, Diana Monica; Socalici, Ana

2012-09-01

379

Microstructure and mechanical properties of diffusion bonded W/steel joint using V/Ni composite interlayer  

SciTech Connect

Diffusion bonding between W and steel using V/Ni composite interlayer was carried out in vacuum at 1050 C and 10 MPa for 1 h. The microstructural examination and mechanical property evaluation of the joints show that the bonding of W to steel was successful. No intermetallic compound was observed at the steel/Ni and V/W interfaces for the joints bonded. The electron probe microanalysis and X-ray diffraction analysis revealed that Ni{sub 3}V, Ni{sub 2}V, Ni{sub 2}V{sub 3} and NiV{sub 3} were formed at the Ni/V interface. The tensile strength of about 362 MPa was obtained for as-bonded W/steel joint and the failure occurred at W near the V/W interface. The nano-indentation test across the joining interfaces demonstrated the effect of solid solution strengthening and intermetallic compound formation in the diffusion zone. - Highlights: Diffusion bonding of W to steel was realized using V/Ni composite interlayer. The interfacial microstructure of the joint was clarified. Several VNi intermetallic compounds were formed in the interface region. The application of V/Ni composite interlayer improved the joining quality.

Liu, W.S.; Cai, Q.S., E-mail: cai2009pm@163.com; Ma, Y.Z.; Wang, Y.Y.; Liu, H.Y.; Li, D.X.

2013-12-15

380

Mechanical-property degradation of cast stainless steel components from the Shippingport reactor  

SciTech Connect

The mechanical properties of cast stainless steels from the Shippingport reactor have been characterized. Baseline properties for unaged materials were obtained from tests on either recovery-annealed material or material from a cooler region of the component. The materials exhibited modest decrease in impact energy and fracture toughness and a small increase in tensile strength. The fracture toughness J-R curve, J{sub IC} value, tensile flow stress, and Charpy-impact energy of the materials showed very good agreement with estimations based on accelerated laboratory aging studies. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy that would be achieved after long-term aging, were established from materials that were aged further in the laboratory at temperatures between 320 and 400{degrees}C. The results showed very good agreement with estimates; the activation energies ranged from 125 to 250 kJ/mole and the minimum room temperature impact energy was <75 J/cm{sup 2}. The estimated impact energy and fracture toughness J-R curve for materials from the Ringhals reactor hot and crossover-leg elbows are also presented.

Chopra, O.K.

1991-10-01

381

Comparison of wear properties of tool steels AISI D2 and O1 with the same hardness  

Microsoft Academic Search

Two commercial cold work tool steels, AISI D2 and O1, were heat treated in order to obtain the same hardness 700HV (60HRc) and were subsequently tested in three different modes of wear, namely in adhesion, three-body and two-body abrasion, by using pin-on-disk, dry sand\\/rubber wheel apparatus and pin abrasion on SiC, respectively. Even though AISI O1 and D2 steel are

L. Bourithis; G. D. Papadimitriou; J. Sideris

2006-01-01

382

Damage Location in Steel Bridges by Acoustic Emission  

Microsoft Academic Search

This paper explores the use of acoustic emission (AE) for damage location in steel composite bridges. Damage assessment of a steel-concrete composite bridge is obtained using conventional time-of-arrival location techniques in both global and local monitoring trials. The local monitoring aspect of the field investigation is simulated under laboratory conditions and waveforms acquired during both studies are compared. A Finite

K. M. Holford; A. W. Davies; R. Pullin; D. C. Carter

2001-01-01

383

Mechanical, microstructure and texture properties of interstitial-free steel and copper subjected to equal channel angular extrusion and cold-rolling  

NASA Astrophysics Data System (ADS)

Interstitial-free steel and OFHC copper were subjected to 8 passes, route BC room temperature ECAE followed by cold-rolling up to 97.5% thickness reduction. Uniaxial tensile tests and Electron Back-Scattering Diffraction were used to characterise the evolution in mechanical properties, microstructure refinement and micro-texture. IF-steel showed continuous increase in strength whereas Cu returned reduced strength and a small gain in ductility at 97.5% reduction. In both metals substructure refinement was accompanied by an increase in high-angle boundary fraction, average misorientation and a slight increase in ?3 boundaries. An evolution of crystallographic orientations from negative shear to predominantly cold-rolled textures after 95% and 97.5% reduction was observed in both metals.

Gazder, A. A.; Hazra, S. S.; Gu, C. F.; Cao, W. Q.; Davies, C. H. J.; Pereloma, E. V.

2010-07-01

384

Corrosion Inhibition and Adsorption Properties of Ethanol Extract of Vernonia Amygdalina for the Corrosion of Mild Steel in H2SO4  

Microsoft Academic Search

Inhibitive and adsorption properties of ethanol extract of vernonia amygdalina for the corrosion of mild steel were studied using weight loss, thermometric, gasometric and IR methods of monitoring corrosion. The results revealed that ethanol extract of Vernonia amygdalina inhibited the corrosion of mild steel. The inhibition efficiency of the extract increased as the concentration of the extract increases. The inhibitor

A. O. Odiongenyi; S. A. Odoemelam; N. O. Eddy

2009-01-01

385

Study on microstructures and mechanical properties of laser-arc hybrid welded S355J2W+N steel  

NASA Astrophysics Data System (ADS)

The technology of laser-MAG hybrid welding was used on 16 mm thick plate of weathering steel S355J2W+N. Under the welding parameters used in the experiment, full penetration weld without flaws such as pores, cracks and lack of fusion was obtained by a three-layer and three-pass welding technique. In this study, the outstanding advantages of laser-arc hybrid welding were summarized by comparison with welded joint of traditional MAG welding. The microstructure of hybrid welded joint has also been detailed investigated. Besides, the mechanical property tests were performed according to corresponding European standards. Furthermore, the tensile and impact strength of laser-MAG hybrid welded joint turned out to be almost as good as base metal. Most of the hybrid welded joints had a good bending property, but for some sample, there was a micro-crack with the length of 0.9 mm emerging within the transition region where contraction stress would accumulate and remain, being one of the most vulnerable zones in weld metal. The results show that laser-MAG hybrid welding technology is appropriate for S355J2W+N thick plate welding, in favor of not only improving the product performance, but also lowering the production cost and improving the productivity.

Zhen, Shu; Duan, Zhenzhen; Sun, Daqian; Li, Yexiong; Gao, Dandan; Li, Hongmei

2014-07-01

386

Corrosion resistance and mechanical properties of low-alloy steels under atmospheric conditions  

Microsoft Academic Search

The corrosion resistance and mechanical strength of four newly developed low-alloy steels (LAS) were compared with a carbon steel (SS400) and a weathering steel (Acr-Ten A) using a laboratory-accelerated test that involved cyclic wet\\/dry conditions in a chloride environment (5 wt.% NaCl). The new LAS were designated 1605A, 1605B, 1604A, and 1604B. After 72 cycles of cyclic corrosion tests, the

Y. Y. Chen; H. J. Tzeng; L. I. Wei; L. H. Wang; J. C. Oung; H. C. Shih

2005-01-01

387

Effect of manganese on the martensite transformation temperature and properties of stainless steels at low temperatures  

Microsoft Academic Search

1.Stainless steels with 14%Cr, 3.8%Ni, and 0.4%Ti, depending on the manganese concentration (816%), can be divided into two groups according to the stability of austenite with respect to the ??a transformation: a) Steels containing 810%Mn have a ??a' transformation (below 0C) and also a ??a? transformation; b) in steels with 1216%Mn the transformation occurs only under the combined influence of

E. A. Ul'yanin; N. A. Sorokina; V. I. Fedorova

1968-01-01

388

Microstructure and properties of low manganese and niobium containing HIC pipeline steel  

Microsoft Academic Search

The paper describes the concept of using low manganese content in pipeline steels for hydrogen-induced cracking (HIC) applications. The microstructure of thermomechanically processed pipeline steel primarily consisted of polygonal ferrite and low fraction of pearlite. The cleanliness of the steel was evident as was the absence of centerline segregation. The microstructure contained high dislocation density, sub-boundaries and dislocation substructures. Fine-scale

S. S. Nayak; R. D. K. Misra; J. Hartmann; F. Siciliano; J. M. Gray

2008-01-01

389

Direct Experimental Observations on Concurrent Microstructure and Magnetic Property Developments in Non-Grain Oriented Electrical Steel  

NASA Astrophysics Data System (ADS)

Non-grain oriented electrical steel, with minor in-grain orientation gradients, was subjected to interrupted tensile deformations and concurrent microtexture, magnetic property and residual stress measurements. After the upper yield point, clear signatures of mechanical stress relief were observed. Changes in orientation gradients led to annihilation of low-angle (1 to 3 deg) boundaries. Prior deformation compressive residual stresses became tensile and magnetic properties improved. Beyond an optimum true strain of 0.01, this boundary annihilation ceased, compressive stresses were generated, and magnetic properties degraded.

Shekhawat, S. K.; Basavaraj, V.; Hiwarkar, V. D.; Chakrabarty, R.; Nemade, J.; Guruprasad, P. J.; Suresh, K. G.; Doherty, R. D.; Samajdar, I.

2014-08-01

390

Research on the mechanical properties of a glass fiber reinforced polymer-steel combined truss structure.  

PubMed

An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status. PMID:25247203

Liu, Pengfei; Zhao, Qilin; Li, Fei; Liu, Jinchun; Chen, Haosen

2014-01-01

391

Research on the Mechanical Properties of a Glass Fiber Reinforced Polymer-Steel Combined Truss Structure  

PubMed Central

An assembled plane truss structure used for vehicle loading is designed and manufactured. In the truss, the glass fiber reinforced polymer (GFRP) tube and the steel joint are connected by a new technology featuring a pretightened tooth connection. The detailed description for the rod and node design is introduced in this paper, and a typical truss panel is fabricated. Under natural conditions, the short-term load test and long-term mechanical performance test for one year are performed to analyze its performance and conduct a comparative analysis for a reasonable FEM model. The study shows that the design and fabrication for the node of an assembled truss panel are convenient, safe, and reliable; because of the creep control design of the rods, not only does the short-term structural stiffness meet the design requirement but also the long-term creep deformation tends towards stability. In addition, no significant change is found in the elastic modules, so this structure can be applied in actual engineering. Although the safety factor for the strength of the composite rods is very large, it has a lightweight advantage over the steel truss for the low density of GFRP. In the FEM model, simplifying the node as a hinge connection relatively conforms to the actual status. PMID:25247203

Liu, Pengfei; Zhao, Qilin; Li, Fei; Liu, Jinchun; Chen, Haosen

2014-01-01

392

Gap Analysis of Material Properties Data for Ferritic/Martensitic HT-9 Steel  

SciTech Connect

The US Department of Energy (DOE), Office of Nuclear Energy (NE), is supporting the development of an ASME Code Case for adoption of 12Cr-1Mo-VW ferritic/martensitic (F/M) steel, commonly known as HT-9, primarily for use in elevated temperature design of liquid-metal fast reactors (LMFR) and components. In 2011, Los Alamos National Laboratory (LANL) nuclear engineering staff began assisting in the development of a small modular reactor (SMR) design concept, previously known as the Hyperion Module, now called the Gen4 Module. LANL staff immediately proposed HT-9 for the reactor vessel and components, as well as fuel clad and ducting, due to its superior thermal qualities. Although the ASME material Code Case, for adoption of HT-9 as an approved elevated temperature material for LMFR service, is the ultimate goal of this project, there are several key deliverables that must first be successfully accomplished. The most important key deliverable is the research, accumulation, and documentation of specific material parameters; physical, mechanical, and environmental, which becomes the basis for an ASME Code Case. Time-independent tensile and ductility data and time-dependent creep and creep-rupture behavior are some of the material properties required for a successful ASME Code case. Although this report provides a cursory review of the available data, a much more comprehensive study of open-source data would be necessary. This report serves three purposes: (a) provides a list of already existing material data information that could ultimately be made available to the ASME Code, (b) determines the HT-9 material properties data missing from available sources that would be required and (c) estimates the necessary material testing required to close the gap. Ultimately, the gap analysis demonstrates that certain material properties testing will be required to fulfill the necessary information package for an ASME Code Case.

Brown, Neil R. [Los Alamos National Laboratory; Serrano De Caro, Magdalena [Los Alamos National Laboratory; Rodriguez, Edward A. [Global Nuclear Network Analysis, LLC

2012-08-28

393

Microstructure and properties of spray formed Cr 12MoV steel for rolls  

Microsoft Academic Search

Cr12MoV steel was chosen as the material for spray forming to develop a new type of advanced roll. The as-sprayed Cr12MoV steel has a relatively homogeneous and fine microstructure, which has a finer, more uniform carbide dispersion, and less segregation of Cr than the conventionally processed Cr12MoV steel. The as-sprayed Cr12MoV steel has an average value of density of 7.75g\\/cm3,

Jing Guo Zhang; Han Bin Xu; Hai Sheng Shi; Jian Shen Wu; De Sheng Sun

2001-01-01

394

The effects of tritium and decay helium on the fracture toughness properties of stainless steels  

SciTech Connect

J-integral fracture mechanics techniques and scanning electron microscopy observations were used to investigate the effects of tritium and its decay product, helium-3, on Types 304L, 316L, 21-6-9, A286, and JBK-75 (Modified A286) stainless steels. Tritium-exposed samples of each steel had lower fracture toughness values and less resistance to stable crack growth than control samples. Type 316L stainless steel was more resistant to the embrittling effects of tritium and decay helium than the other steels.

Morgan, M.J.

1991-12-31

395

The effects of tritium and decay helium on the fracture toughness properties of stainless steels  

SciTech Connect

J-integral fracture mechanics techniques and scanning electron microscopy observations were used to investigate the effects of tritium and its decay product, helium-3, on Types 304L, 316L, 21-6-9, A286, and JBK-75 (Modified A286) stainless steels. Tritium-exposed samples of each steel had lower fracture toughness values and less resistance to stable crack growth than control samples. Type 316L stainless steel was more resistant to the embrittling effects of tritium and decay helium than the other steels.

Morgan, M.J.

1991-01-01

396

Residual Stresses in Steel Specimens Induced by Laser Cladding and their Effect on Fatigue Strength  

NASA Astrophysics Data System (ADS)

Residual stresses resulting from circumferential laser cladding of fatigue test specimen of austenitic steel X5CrNi18-10 and heat treatable steel 42CrMo4 with Stellite 21 are evaluated by neutron diffraction. Below the interface of cladding and base material the former shows compressive residual stresses, the latter shows tensile residual stresses. Locations of crack initiation during fatigue testing correlate to the findings. Austenitic steel specimens crack at the surface whereas heat treatable steel components and specimens crack close to the interface. Fatigue strength of both material systems drops due to laser cladding whereby the drop of heat treatable steel is significant. It can be concluded that residual stress distribution needs to be optimized in order to conserve maximal fatigue strength.

Khler, Henry; Partes, Knut; Kornmeier, Joana Rebelo; Vollertsen, Frank

397

HYDROGEN OUTGASSING AND SURFACE PROPERTIES OF TIN COATED STAINLESS STEEL CHAMBERS.  

SciTech Connect

The stainless steel vacuum chambers of the 248m accumulator ring of Spallation Neutron Source (SNS) are coated with {approx} 100 nm of titanium nitride (TiN) to reduce the secondary electron yield. The coating is produced by DC magnetron sputtering using a long cathode imbedded with permanent magnets. The outgassing rates of several SNS half-cell chambers were measured with and without TiN coating, and before and after in-situ bake. One potential benefit of a TiN coating is to serve as hydrogen permeation barrier that reduces the ultimate outgassing rate. By varying the coating parameters, films of different surface roughness were produced and analyzed by Auger electron spectroscopy, scanning electron microscopy and atomic force microscopy to illustrate the dependence of the outgassing on the film structure.

HE,P.; HSEUH,H.C.; MAPES,M.; TODD,R.; WEISS,D.; WILSON,D.

2002-11-11

398

Diffusion Bonding of Microduplex Stainless Steel and Ti Alloy with and without Interlayer: Interface Microstructure and Strength Properties  

NASA Astrophysics Data System (ADS)

The interface microstructure and strength properties of solid state diffusion bonding of microduplex stainless steel (MDSS) to Ti alloy (TiA) with and without a Ni alloy (NiA) intermediate material were investigated at 1173 K (900 C) for 0.9 to 5.4 ks in steps of 0.9 ks in vacuum. The effects of bonding time on the microstructure of the bonded joint have been analyzed by light optical microscopy and scanning electron microscopy in the backscattered mode. In the direct bonded joints of MDSS and TiA, the layer-wise ? phase and the ? + FeTi phase mixture were observed at the bond interface when the joint was processed for 2.7 ks and above holding times. However, when NiA was used as an intermediate material, the results indicated that TiNi3, TiNi, and Ti2Ni are formed at the NiA-TiA interface, and the irregular shaped particles of Fe22Mo20Ni45Ti13 have been observed within the TiNi3 intermetallic layer. The stainless steel-NiA interface is free from intermetallics and the layer of austenitic phase was observed at the stainless steel side. A maximum tensile strength of ~520 MPa, shear strength of ~405 MPa, and impact toughness of ~18 J were obtained for the directly bonded joint when processed for 2.7 ks. However, when nickel base alloy was used as an intermediate material in the same materials, the bond tensile and shear strengths increase to ~640 and ~479 MPa, respectively, and the impact toughness to ~21 J when bonding was processed for 4.5 ks. Fracture surface observations in scanning electron microscopy using energy dispersive spectroscopy demonstrate that in MDSS-TiA joints, failure takes place through the FeTi + ? phase when bonding was processed for 2.7 ks; however, failure takes place through ? phase for the diffusion joints processed for 3.6 ks and above processing times. However, in MDSS-NiA-TiA joints, the fracture takes place through NiTi2 layer at the NiA-TiA interface for all bonding times.

Kundu, S.; Sam, S.; Mishra, B.; Chatterjee, S.

2014-01-01

399

Large recovery strain in Fe-Mn-Si-based shape memory steels obtained by engineering annealing twin boundaries.  

PubMed

Shape memory alloys are a unique class of materials that can recover their original shape upon heating after a large deformation. Ti-Ni alloys with a large recovery strain are expensive, while low-cost conventional processed Fe-Mn-Si-based steels suffer from a low recovery strain (<3%). Here we show that the low recovery strain results from interactions between stress-induced martensite and a high density of annealing twin boundaries. Reducing the density of twin boundaries is thus a critical factor for obtaining a large recovery strain in these steels. By significantly suppressing the formation of twin boundaries, we attain a tensile recovery strain of 7.6% in an annealed cast polycrystalline Fe-20.2Mn-5.6Si-8.9Cr-5.0Ni steel (weight%). Further attractiveness of this material lies in its low-cost alloying components and simple synthesis-processing cycle consisting only of casting plus annealing. This enables these steels to be used at a large scale as structural materials with advanced functional properties. PMID:25230134

Wen, Y H; Peng, H B; Raabe, D; Gutierrez-Urrutia, I; Chen, J; Du, Y Y

2014-01-01

400

Large recovery strain in Fe-Mn-Si-based shape memory steels obtained by engineering annealing twin boundaries  

NASA Astrophysics Data System (ADS)

Shape memory alloys are a unique class of materials that can recover their original shape upon heating after a large deformation. Ti-Ni alloys with a large recovery strain are expensive, while low-cost conventional processed Fe-Mn-Si-based steels suffer from a low recovery strain (<3%). Here we show that the low recovery strain results from interactions between stress-induced martensite and a high density of annealing twin boundaries. Reducing the density of twin boundaries is thus a critical factor for obtaining a large recovery strain in these steels. By significantly suppressing the formation of twin boundaries, we attain a tensile recovery strain of 7.6% in an annealed cast polycrystalline Fe-20.2Mn-5.6Si-8.9Cr-5.0Ni steel (weight%). Further attractiveness of this material lies in its low-cost alloying components and simple synthesis-processing cycle consisting only of casting plus annealing. This enables these steels to be used at a large scale as structural materials with advanced functional properties.

Wen, Y. H.; Peng, H. B.; Raabe, D.; Gutierrez-Urrutia, I.; Chen, J.; Du, Y. Y.

2014-09-01

401

EFFECT OF RUST ON THE WETTABILITY OF STEEL BY WATER W. Lu and D.D.L. Chung1  

E-print Network

EFFECT OF RUST ON THE WETTABILITY OF STEEL BY WATER W. Lu and D.D.L. Chung1 Composite Materials Research Laboratory, State University of New York at Buffalo, Buffalo, NY 14260-4400, USA (Received-carbon steel in water, was found to improve the wettability of steel by water. The advancing contact angle

Chung, Deborah D.L.

402

Increase of Austenite Grain Coarsening Temperature in Banded Ferrite/Pearlite Steel by Cold Deformation  

NASA Astrophysics Data System (ADS)

The grain coarsening temperature ( T c) is quite low in a ferrite/pearlite (F/P) banded steel as compared with a non-banded steel. Here it is shown that the low T c in the F/P banded steel can be increased significantly by applying cold deformation prior to austenitizing. The kinetics of abnormal grain coarsening above T c is also largely retarded by cold deformation. These observations should be attributed to the uniform distribution of fine AlN precipitates caused by cold deformation.

Zhang, Xianguang; Matsuura, Kiyotaka; Ohno, Munekazu

2015-01-01

403

Effects of DC plasma nitriding parameters on microstructure and properties of 304L stainless steel  

SciTech Connect

A wear-resistant nitrided layer was formed on a 304L austenitic stainless steel substrate by DC plasma nitriding. Effects of DC plasma nitriding parameters on the structural phases, micro-hardness and dry-sliding wear behavior of the nitrided layer were investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, micro-hardness testing and ring-on-block wear testing. The results show that the highest surface hardness over a case depth of about 10 {mu}m is obtained after nitriding at 460 deg. C. XRD indicated a single expanded austenite phase and a single CrN nitride phase were formed at 350 deg. C and 480 deg. C, respectively. In addition, the S-phase layers formed on the samples provided the best dry-sliding wear resistance under the ring-on-block contact configuration test.

Wang Jun [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China); Nuclear Power Institute of China, Chengdu 610041 (China); Xiong Ji [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China)], E-mail: scutg@163.com; Peng Qian [Nuclear Power Institute of China, Chengdu 610041 (China); Fan Hongyuan [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China); Wang Ying [Nuclear Power Institute of China, Chengdu 610041 (China); Li Guijiang; Shen Baoluo [School of Manufacturing Science and Engineering, Sichuan University, Chengdu 610065 (China)

2009-03-15

404

Examination of surface conditions and other physical properties of commonly used stainless steel acupuncture needles  

PubMed Central

Objectives The present work examined the surface conditions and various other physical properties of sterilised single-use stainless steel acupuncture needles from two of the most popular brands widely used in many countries. Methods Scanning electron microscope (SEM) images were taken for 10 randomly chosen needles from each brand. Further SEM images were taken after each of these needles underwent a standard manipulation with an acupuncture needling practice gel. A comparison of forces and torques during the needling process was also carried out. Results The SEM images revealed significant surface irregularities and inconsistencies at the needle tips, especially for needles from one of the two brands. Metallic lumps and small, loosely attached pieces of material were observed on the surfaces of some needles. Some of the lumps and pieces of material seen on the needle surfaces disappeared after the acupuncture manipulation. If these needles had been used on patients, the metallic lumps and small pieces of material could have been deposited in human tissues, which could have caused adverse events such as dermatitis. Malformed needle tips might also cause other adverse effects including bleeding, haematoma/bruising, or strong pain during needling. An off-centre needle tip could result in the needle altering its direction during insertion and consequently failing to reach the intended acupuncture point or damaging adjacent tissues. Conclusions These findings highlight the need for improved quality control of acupuncture needles, with a view to further enhancing the safety and comfort of acupuncture users. PMID:24522003

Xie, Yi Min; Xu, Shanqing; Zhang, Claire Shuiqing; Xue, Charlie Changli

2014-01-01

405

Influence of cleaning pretreatments on tribological properties of zinc phosphated steels  

Microsoft Academic Search

Among lubrication processes for cold forging of steel, phosphating is the most common. Depending on contact between piece and phosphating solution, the success of this treatment depends on steel surface preparation. Despite this obvious fact, the influence of cleaning pretreatments such as degreasing and acid pickling are seldom considered from a mechanical point of view and specially from a tribological

Philippe Hivart; Jean-Paul Bricout

2003-01-01

406

Some Properties of Factors of Specific Total Loss Components in Electrical Steel  

Microsoft Academic Search

One of the most important parameters of electrical steel sheet is specific total loss. In order to analyze the specific total loss, seven electrical steel grades were separated into three components: the hysteresis loss component and both the classical and additional eddy current loss components. Parameters used for the description of loss components in statistical loss models were analyzed and

Wojciech A. Pluta

2010-01-01

407

Effect of steel fiber on the mechanical properties of oil palm shell lightweight concrete  

Microsoft Academic Search

This paper reports the results of a study conducted to investigate the effect of low volume content of steel fiber on the slump, density, compressive strength under different curing conditions, splitting tensile strength, flexural strength and modulus of elasticity of a grade 35 oil palm shell (OPS) lightweight concrete mixture. The results indicate that an increase in steel fiber decreased

Payam Shafigh; Hilmi Mahmud; Mohd Zamin Jumaat

2011-01-01

408

The ballistic properties of tool steel as a potential improvised armour plate  

Microsoft Academic Search

The ballistic behaviour of a 0.95 weight per cent carbon tool steel against 7.62 mm ball and armour piercing bullets was investigated in the unwelded and welded condition. Gross cracking occurred at plate hardnesses of 510 HV and greater. The mode of perforation for tool steel of hardness 380 H V, which was petalling for 5 mm thick plates and

M. R. Edwards; A. Mathewson

1997-01-01

409

Degradation of Properties of Long Term Exploited Main Oil and Gas Pipelines Steels and Role of Environment in This Process  

Microsoft Academic Search

\\u000a Comparison of mechanical (characteristics of strength, reduction of area and elongation, impact strength, hardness, fracture\\u000a toughness), corrosion (corrosion rate and electrochemical parameters), corrosion-mechanical (stress corrosion cracking and\\u000a hydrogen embrittlement) properties and parameters of hydrogen behaviour in the oil and gas pipelines steels in the as-received\\u000a state and after 2840years of service are presented in the paper. Transported hydrocarbons serve as

H. M. Nykyforchyn; E. Lunarska; P. Zonta

410

Effect of friction stir welding speed on the microstructure and mechanical properties of a duplex stainless steel  

Microsoft Academic Search

The present study focuses on the effect of the welding speed on the microstructure and mechanical properties of the stir zone (SZ) in friction stir welding (FSW) of SAF 2205 duplex stainless steel. A single tool, made of a WC-base material, was used to weld 2mm-thick plates at a constant rotational speed of 600rpm. X-ray radiography revealed that sound welds

T. Saeid; A. Abdollah-zadeh; H. Assadi; F. Malek Ghaini

2008-01-01

411

Effect of impact energy on the impact-wear properties of low carbon high manganese alloy steels in corrosive conditions  

Microsoft Academic Search

The impact-wear properties of low carbon high manganese alloy steel were tested under three different impact energies (0.7\\u000a J, 1.2 J and 1.7 J) using a modified MLD-10 wear tester. SEM inspection of the wear surface and subsurface optical metallographic\\u000a analysis reveal the impact wear mechanism. Under corrosive conditions we observe a shift from single micro-cutting to impact-flaking,\\u000a after the

Kai Wang; Xiao-Dong Du; Kuk-Tae Youn; Yasunori Hayashi; Chan Gyu Lee; Bon Heun Koo

2008-01-01

412

Determining irradiation damage and recovery by instrumented indentation in RAFM steel  

NASA Astrophysics Data System (ADS)

The mechanical behavior of specific reduced-activation ferritic-martensitic steels (RAFM), designed for fusion applications, is investigated in the present study. Eurofer97 and F82H-mod specimens have been neutron-irradiated in the High Flux Reactor at Petten (HFR) up to a dose of 15 dpa at 250-450 C. An indentation method [1], making use of a data post-analysis program based on neural networks, has been employed to identify tensile properties by multistage indents. The significant irradiation-induced hardening effect present at 15 dpa in the range of 250-350 C could be observed in Vickers hardness and in the calculated material's strength parameters, the influence of the pre-irradiation heat treatment could be identified. Post-irradiation annealing treatments have been realized at 500 C and 550 C and leads to a partial recovery of the irradiation damage.

Sacksteder, I.; Schneider, H.-C.; Materna-Morris, E.

2011-10-01

413

NiCrSiB Coatings Deposited by Plasma Transferred Arc on Different Steel Substrates  

NASA Astrophysics Data System (ADS)

Colmonoy 6 (NiCrSiB) is a Ni-based alloy recognized for its superior mechanical properties, attributed to the presence of a dispersion of hard carbides and borides, which is strongly dependent on processing technique. This work gathered microstructure data from the literature and analyzed Colmonoy 6 coatings deposited by plasma transferred arc hardfacing. The aim of the study was to determine the influence of PTA deposition parameters and substrate chemical composition on NiCrSiB coating characteristics. Coatings were characterized in terms of their hardness, dilution, and microstructure, as well as mass loss during abrasive sliding wear tests. The results showed that coating performance is strongly dependent on the chemical composition of the substrate. Carbon steel substrate yielded coatings with greater wear resistance. Processing parameters also alter the performance of coatings, and the lower current and lower travel speed result in reduced mass loss.

Reinaldo, P. R.; D'Oliveira, A. S. C. M.

2013-02-01

414

Asymmetric Rolling of Interstitial-Free Steel Using Differential Roll Diameters. Part I: Mechanical Properties and Deformation Textures  

NASA Astrophysics Data System (ADS)

IF steel sheets were processed by conventional symmetric and asymmetric rolling (ASR) at ambient temperature. The asymmetry was introduced in a geometric way using differential roll diameters with a number of different ratios. The material strength was measured by tensile testing and the microstructure was analyzed by optical and transmission electron microscopy as well as electron backscatter diffraction (EBSD) analysis. Texture was also successfully measured by EBSD using large surface areas. Finite element (FE) simulations were carried out for multiple passes to obtain the strain distribution after rolling. From the FE results, the velocity gradient along selected flow lines was extracted and the evolution of the texture was simulated using polycrystal plasticity modeling. The best mechanical properties were obtained after ASR using a roll diameter ratio of 2. The textures appeared to be tilted up to 12 deg around the transverse direction, which were simulated with the FE-combined polycrystal plasticity modeling in good agreement with measurements. The simulation work revealed that the shear component introduced by ASR was about the same magnitude as the normal component of the rolling strain tensor.

Orlov, Dmitry; Pougis, Arnaud; Lapovok, Rimma; Toth, Laszlo S.; Timokhina, Ilana B.; Hodgson, Peter D.; Haldar, Arunansu; Bhattacharjee, Debashish

2013-09-01

415

Dynamic Tensile Properties of Iron and Steels for a Wide Range of Strain Rates and Strain  

NASA Astrophysics Data System (ADS)

The tensile stress-strain curves of iron and a variety of steels, covering a wide range of strength level, over a wide strain rate range on the order of 10-3 ~ 103 s-1, were obtained systematically by using the Sensing Block Type High Speed Material Testing System (SBTS, Saginomiya). Through intensive analysis of these results, the strain rate sensitivity of the flow stress for the large strain region, including the viscous term at high strain rates, the true fracture strength and the true fracture strain were cleared for the material group of the ferrous metals. These systematical data may be useful to develop a practical constitutive model for computer codes, including a fracture criterion for simulations of the dynamic behavior in crash worthiness studies and of work-pieces subjected to dynamic plastic working for a wide strain rate range.

Kojima, Nobusato; Hayashi, Hiroyuki; Yamamoto, Terumi; Mimura, Koji; Tanimura, Shinji

416

Mechanical Properties of 17-4PH Stainless Steel Foam Panels  

NASA Technical Reports Server (NTRS)

Rectangular 17-4PH stainless steel sandwiched foam panels were fabricated using a commercial manufacturing technique by brazing two sheets to a foam core. Microstructural observations and ultrasonic nondestructive evaluation of the panels revealed large variations in the quality of the brazed areas from one panel to the next as well as within the same panel. Shear tests conducted on specimens machined from the panels exhibited failures either in the brazed region or in the foam core for the poorly brazed and well-brazed samples, respectively. Compression tests were conducted on the foam cores to evaluate their elastic and plastic deformation behavior. These data were compared with published data on polymeric and metallic foams, and with theoretical deformation models proposed for open cell foams.

Raj, S. V.; Ghosn, L. J.; Lerch, B. a.; Hebsur, M.; Cosgriff, L. M.; Fedor, J.

2007-01-01

417

Solidification of stainless steel slag by accelerated carbonation.  

PubMed

On exposure to carbon dioxide (CO2) at a pressure of 3 bars, compacts formed from pressed ground slag, and 12.5 weight percent water, were found to react with approximately 18% of their own weight of CO2. The reaction product formed was calcium carbonate causing the slag to self-cement. Unconfined compressive strengths of 9MPa were recorded in carbonated compacts whereas strengths of < 1 MPa were recorded in non-carbonated slag compacts. As molten stainless steel slag containing dicalcium silicate (C2S) cools it can undergo several phase transitions. The final transformation from the beta-polymorph to gamma-C2S is accompanied by a volume change that causes the slag to self-pulverise or 'dust'. As a consequence of this the fine grained portion of the slag contains more of this phase whilst the coarser particles of the slag contain more of the calcium magnesium silicates that contribute the bulk of the waste. The fine fraction (< 125 microm) of the slag when ground is found to react to the same extent as the ground bulk slag and produces compacts with equivalent strength. A coarser fraction (4-8 mm) when ground to a similar grading does not react as extensively and produces a weaker product. Additions of ordinary Portland cement (OPC) at 5 and 10 percent by weight did not alter the degree of reaction during carbonation of the bulk slag or ground fine fraction, however the strength of the 4-8 mm fraction was increased by this change. PMID:12868521

Johnson, D C; MacLeod, C L; Carey, P J; Hills, C D

2003-06-01

418

Evolution of Recrystallization by Changes in Magnetic Hysteresis Loop in a Non-Oriented Electric Steel Cold Rolled  

Microsoft Academic Search

Non-oriented steels, with low carbon, are widely used in the fabrication of electrical motor nucleus. The performance of these motors is affected by the level of recrystallization. These steels can come from the steel plant in two different conditions: totally processed or semi-processed. The semi-processed steels have a partially deformed structure and are submitted to the final annealing process after

F. E. da Silva; F. N. C. Freitas; H. F. G. Abreu; L. L. Gonalves; E. P. Moura; M. R. Silva

2011-01-01

419

EVOLUTION OF RECRYSTALLIZATION BY CHANGES IN MAGNETIC HYSTERESIS LOOP IN A NON-ORIENTED ELECTRIC STEEL COLD ROLLED  

Microsoft Academic Search

Non-oriented steels, with low carbon, are widely used in the fabrication of electrical motor nucleus. The performance of these motors is affected by the level of recrystallization. These steels can come from the steel plant in two different conditions: totally processed or semi-processed. The semi-processed steels have a partially deformed structure and are submitted to the final annealing process after

F. E. da Silva; F. N. C. Freitas; H. F. G. Abreu; E. P. Moura; M. R. Silva

2011-01-01

420

Numerical simulation of dynamic fracture of concrete targets impacted by steel rods  

Microsoft Academic Search

Numerical simulation of dynamic fracture of concrete target blocks, impacted by steel projectiles, was performed in the present study. The specific impact configuration of this study follows the experiment series conducted by Hanchak et al., where 610 610 178mm³ reinforced concrete blocks were impacted by 25.4 mm diameter, 143.7 mm long, 0.5 kg, 3.0 caliber-radius-head, ogival nose steel

1992-01-01

421

Developing a Technology for Rolling Low-Alloy Steel Plates by Modeling the Structure-Forming Processes  

Microsoft Academic Search

Controlled rolling is widely recognized as an effective means of improving the properties of steels [1, 2]. However, its use requires powerful rolling equipment and steels of optimum chemical composition. The technology need not be used when the requirements for the rolling operation are less stringent ? other rolling regimes executed at higher temperatures can be used. That makes it

L. I. fron; N. P. Mel'nik; I. V. Ganoshenko; V. V. Volodarskii

2001-01-01

422

Corrosion inhibition of mild steel by aerobic biofilm  

Microsoft Academic Search

Mild steel electrodes were incubated in phosphate-buffered basal salt solution (BSS) having two different aerobic bacteria, viz. Pseudomonas alcaligenes and Pseudomonas cichorii. In the medium containing P. cichorii, significant reduction in the corrosion rate was observed due to the surface reaction leading to the formation of corrosion inhibiting bacterial biofilm. With a view to understand the mechanism of microbially influenced

Shobhana Chongdar; G. Gunasekaran; Pradeep Kumar

2005-01-01

423

Fast fabrication of long TiO2 nanotube array with high photoelectrochemical property on flexible stainless steel.  

PubMed

Oriented highly ordered long TiO2 nanotube array films with nanopore structure and high photoelectrochemical property were fabricated on flexible stainless steel substrate (50 microm) by anodization treatment of titanium thin films in a short time. The samples were characterized by means of field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and photoelectrochemical methods, respectively. The results showed that Ti films deposited at the condition of 0.7 Pa Ar pressure and 96 W sputtering power at room temperature was uniform and dense with good homogeneity and high crystallinity. The voltage and the anodization time both played significant roles in the formation of TiO2 nanopore-nanotube array film. The optimal voltage was 60 V and the anodization time is less than 30 min by anodizing Ti films in ethylene glycerol containing 0.5% (w) NH4F and 3% (w) H2O. The growth rate of TiO2 nanotube array was as high as 340 nm/min. Moreover, the photocurrent-potential curves, photocurrent response curves and electrochemical impedance spectra results indicated that the TiO2 nanotube array film with the nanoporous structure exhibited a better photo-response ability and photoelectrochemical performance than the ordinary TiO2 nanotube array film. The reason is that the nanoporous structure on the surface of the nanotube array can separate the photo electron-hole pairs more efficiently and completely than the tubular structure. PMID:22754990

Tao, Jie; Wu, Tao; Gao, Peng

2012-03-01

424

Inhibitive effects of palm kernel oil on carbon steel corrosion by alkaline solution  

NASA Astrophysics Data System (ADS)

The behavior of carbon steel SAE 1045 in 1 M NaOH solution containing different concentrations of palm kernel oil (PKO) has been studied by weight loss and polarization measurement. Results showed that the corrosion of carbon steel in NaOH solution was considerably reduced in presence of such inhibitors. The inhibition efficiency increases when concentration of inhibitor increase. Maximum inhibition efficiency (? 96.67%) is obtained at PKO concentration 8 v/v %. This result revealed that palm kernel oil can act as a corrosion inhibitor in an alkaline medium. Corrosion rates of carbon steel decrease as the concentration of inhibitor is increased.

Zulkafli, M. Y.; Othman, N. K.; Lazim, A. M.; Jalar, A.

2013-11-01

425

Enhancement of the durability of structural steels and their welded joints by plastic deformation  

Microsoft Academic Search

ConclusionsThe fatigue and corrosion-fatigue resistance of low-alloy steels increases as degree of plastic prestraining increases to\\u000a 29%. The resistance of the 08kp steel prestrained and hardened by surface plastic deformation and its welded joints to fatigue\\u000a and corrosion-fatigue fracture is higher than for the 08GSYuT alloyed steel. The procedures of pneumatic shot blasting and\\u000a shot blasting prove to be efficient

M. P. Berezhnytska; H. P. Huslyakova; V. I. Tkachov

2000-01-01

426

Microstructural characterization and properties of Al\\/Cu\\/steel diffusion bonded joints  

Microsoft Academic Search

We prepared Al\\/Cu\\/steel composite with a gradient structure using a vacuum hot-pressed diffusion method and investigated the\\u000a Al\\/Cu\\/steel interface. The results show that a supersaturated solid solution with a thickness of about 2 um formed in the\\u000a Cu\\/steel diffusion zone. Two kinds of intermetallic compounds, Cu9Al4 adjacent to the Cu side and CuAl2 adjacent to the Al side, formed at

Xiaole Cheng; Yimin Gao; Hanguang Fu; Jiandong Xing; Bingzhe Bai

2010-01-01

427

Evaluation of Corrosion in Carbon Steel Pipes by Laser-Generated Guided Wave  

Microsoft Academic Search

\\u000a The objective of this research is to locate and evaluate wall thinning in pipe elbow by a non-contact guided wave technique\\u000a with laser source as a transmitter and air-bone transducer as a receiver, respectively. Wall thinning of carbon steel pipe\\u000a is one of the most serious problems in nuclear industry; especially the one in carbon steel pipe elbow caused by

Do-Youn Kim; Joon-Hyun Lee; Younho Cho; Jaesun Lee; Jan D. Achenbach

428

Improving the bond strength between steel rebar and concrete by oxidation treatments of the rebar  

SciTech Connect

Oxidation treatments of steel rebar by water immersion (2--5 days) and ozone exposure increased the bond strength between steel rebar and concrete by 14% and 22% respectively. The treatments slightly increased the electrical contact resistivity between rebar and concrete. Increase of the water immersion time to 7 or 10 days caused the bond strength to decrease to values still above that of the case without water treatment. The contact resistivity increased monotonically with the water immersion time.

Fu, X.; Chung, D.D.L. [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.] [State Univ. of New York, Buffalo, NY (United States). Composite Materials Research Lab.

1996-10-01

429

Bond characteristics of steel fiber and deformed reinforcing steel bar embedded in steel fiber reinforced self-compacting concrete (SFRSCC)  

NASA Astrophysics Data System (ADS)

Steel fiber reinforced self-compacting concrete (SFRSCC) is a relatively new composite material which congregates the benefits of the self-compacting concrete (SCC) technology with the profits derived from the fiber addition to a brittle cementitious matrix. Steel fibers improve many of the properties of SCC elements including tensile strength, ductility, toughness, energy absorption capacity, fracture toughness and cracking. Although the available research regarding the influence of steel fibers on the properties of SFRSCC is limited, this paper investigates the bond characteristics between steel fiber and SCC firstly. Based on the available experimental results, the current analytical steel fiber pullout model (Dubey 1999) is modified by considering the different SCC properties and different fiber types (smooth, hooked) and inclination. In order to take into account the effect of fiber inclination in the pullout model, apparent shear strengths ( ? ( app)) and slip coefficient ( ?) are incorporated to express the variation of pullout peak load and the augmentation of peak slip as the inclined angle increases. These variables are expressed as functions of the inclined angle ( ?). Furthurmore, steel-concrete composite floors, reinforced concrete floors supported by columns or walls and floors on an elastic foundations belong to the category of structural elements in which the conventional steel reinforcement can be partially replaced by the use of steel fibers. When discussing deformation capacity of structural elements or civil engineering structures manufactured using SFRSCC, one must be able to describe thoroughly both the behavior of the concrete matrix reinforced with steel fibers and the interaction between this composite matrix and discrete steel reinforcement of the conventional type. However, even though the knowledge on bond behavior is essential for evaluating the overall behavior of structural components containing reinforcement and steel fibers, information is hardly available in this area. In this study, bond characteristics of deformed reinforcing steel bars embedded in SFRSCC is investigated secondly.

Aslani, Farhad; Nejadi, Shami

2012-09-01

430

Mechanical properties of Fe -10Ni -7Mn martensitic steel subjected to severe plastic deformation via cold rolling and wire drawing  

NASA Astrophysics Data System (ADS)

Fe-Ni-Mn martensitic steels are one of the major groups of ultra-high strength steels that have good mechanical properties and ductility in as annealed condition but they suffer from severe inter-granular embitterment after aging. In this paper, the effect of heavy shaped cold rolling and wire drawing on the mechanical properties of Fe-Ni-Mn steel was investigated. This process could provide a large strain deformation in this alloy. The total strain was epsilon ~7. Aging behavior and tensile properties of Fe-10Ni-7Mn were studied after aging at 753 K. The results showed that the ultimate tensile strength and ductility after cold rolling, wire drawing and aging increased up to 2540 MPa and 7.1 %, respectively, while the conventional steels show a premature fracture stress of 830 MPa with about zero ductility after aging.

Ghasemi-Nanesa, H.; Nili-Ahmadabadi, M.; Shirazi, H.

2010-07-01

431

Diffusion barrier properties of molybdenum back contacts for Cu(In,Ga)Se2 solar cells on stainless steel foils  

NASA Astrophysics Data System (ADS)

Flexible Cu(In,Ga)Se2 (CIGS) solar cells on stainless steel foils face the problem of efficiency deterioration when iron impurities diffuse into the absorber layer. The influence of the magnetron sputtering conditions and the design of Mo-based back contacts on the property of the diffusion barrier against iron is reported here for high efficiency CIGS solar cells grown at low substrate temperatures (Tmax = 475 C). The overall material density of the Mo back contact was identified as the dominant parameter for the impurity diffusion barrier performance. It was found that this is also true for Mo bilayer contacts, which show enhanced film densities at low residual stress. The iron diffusion profile in the back contact and CIGS was measured by secondary ion mass spectroscopy, where a linear decrease in the iron impurity concentration in the CIGS towards the CdS buffer layer was found. Furthermore, this iron distribution in CIGS and its consequences on the solar cell efficiency is discussed, supported by defect analysis measurements and photovoltaic device simulations. With a stress-free 500 nm thick Mo bilayer back contact, best solar cell efficiencies above 15% were achieved with antireflection coating.

Blsch, P.; Pianezzi, F.; Chiril?, A.; Rossbach, P.; Nishiwaki, S.; Buecheler, S.; Tiwari, A. N.

2013-02-01

432

Experimental Investigation on Thermal Properties of a Steel-jacketed Steam Heating Pipeline with Vacuum Insulation  

E-print Network

The steel-jacketed steam heating pipeline employs vacuum insulation to improve the insulating effect and reduce the corrosion, and hence increases the heat transfer efficiency of the heating network and building energy efficiency. It is important...

Na, W.; Zou, P.

2006-01-01

433

Influence of the Carbo-Chromization Process on the Microstructural, Hardness, and Corrosion Properties of 316L Sintered Stainless Steel  

NASA Astrophysics Data System (ADS)

We report on the changes on the microstructural, hardness, and corrosion properties induced by carbo-chromization of 316L stainless steel prepared by Spark Plasma Sintering technique. The thermo-chemical treatments have been performed using pack cementation. The carburizing and chromization were carried out between 1153 K (880 C)/4 h to 1253 K (980 C)/12 h and 1223 K (950 C)/6 h to 1273 K (1000 C)/12 h in a solid powder mixture of charcoal/BaCO3 and ferrochromium/alumina/NH4Cl, respectively. The obtained layers were investigated using X-ray and electron diffraction, optical and scanning electron microscopies, Vickers micro-hardness, and potentiodynamic measurements. The thickness of the carbo-chromized layer ranges between 300 and 500 ?m. Besides the host ?-phase, the layers are mainly constituted of carbides (Fe7C3, Cr23C6, Cr7C3, and Fe3C) and traces of ?'-martensite. The average hardness values decrease smoothly from 650 HV at the sample surface down to 200 HV at the center of the sample. The potentiodynamic tests revealed that the carbo-chromized samples have smaller corrosion resistance with respect to the untreated material. For strong chromization regimes, the corrosion rate is increased by a factor of four with respect to that of the untreated material, while the micro-hardness of the layer is three times larger. Such materials are suited to be used in environments where good corrosion resistance and wear properties are required.

Iorga, Sorin; Cojocaru, Mihai; Chivu, Adriana; Ciuca, Sorin; Burdusel, Mihail; Badica, Petre; Leuvrey, Cdric; Schmerber, Guy; Ulhaq-Bouillet, Corinne; Colis, Silviu

2014-06-01

434

Electrochemical and Initial Corrosion Behavior of Ultrahigh Strength Steel by Scanning Kelvin Probe  

NASA Astrophysics Data System (ADS)

Electrochemical behavior of ultrahigh strength (UHS) steel (1#) after salt spray test (SST) was studied by means of electrochemical techniques and scanning Kelvin probe, Raman spectroscopy, and scanning electron microscope. The results show that pitting occurs to the samples of 1# steel in SST with 5% NaCl. The corrosion products are mainly ?-FeOOH and oxide/hydroxide of chromium. Within 4 days, corrosion reaction is resisted by the completed corrosion products, and thereafter corrosion rate of 1# steel with corrosion products is accelerated as the SST continues, since the corrosion potential shifts to negative direction and corrosion current density becomes larger. Kelvin potentials of 1# steel after the SST are 0.3-0.4 V higher in magnitude and distributes more unevenly than that before the SST, because the oxide films grow thicker and affect the anodic reaction of corrosion process.

Sun, Min; Xiao, Kui; Dong, Chaofang; Li, Xiaogang; Zhong, Ping

2013-03-01

435

Nickel monoaluminide coating on ultralow-carbon steel by reactive sintering  

SciTech Connect

By sintering a mixture of nickel and aluminum powders on the surface of an ultralow-carbon steel block of 15 mm in thickness, nickel monoaluminide (NiAl) is reaction-synthesized and simultaneously joined to the steel block. When the thickness of the compact powder mixture is above 5 mm, an exothermic, self-propagating high-temperature reaction of Ni + Al {r_arrow} NiAl is induced by heating to approximately 900 K, and the temperature of the compact rises very quickly and exceeds the melting point of NiAl (1911 K). Accordingly, an in situ NiAl coating on the steel is completed in a very short time. When the compact thickness is below 5 mm, on the other hand, the synthesis reaction is incomplete because of heat loss due to absorption by the steel block, and intermediate products such as Ni{sub 3}Al and NiAl{sub 3} remain in the compact. However, the in situ coating is completed by further heating to 1473 K followed by holding for 0.54 ks. Across the interface between the steel and the coating, the concentrations of the elements gradually change and, accordingly, the Vickers hardness continuously changes from approximately 80 in the steel to 350 in the NiAl. The joint strength evaluated from a tensile test is above 150 MPa.

Matsuura, Kiyotaka; Ohsasa, Kenichi; Sueoka, Noritoshi; Kudoh, Masayuki [Hokkaido Univ. (Japan)

1999-06-01

436

Microstructure and properties of pipeline steel with a ferrite/martensite dual-phase microstructure  

SciTech Connect

In order to satisfy the transportation of the crude oil and gas in severe environmental conditions, a ferrite/martensite dual-phase pipeline steel has been developed. After a forming process and double submerged arc welding, the microstructure of the base metal, heat affected zone and weld metal was characterized using scanning electron microscopy and transmission electron microscopy. The pipe showed good deformability and an excellent combination of high strength and toughness, which is suitable for a pipeline subjected to the progressive and abrupt ground movement. The base metal having a ferrite/martensite dual-phase microstructure exhibited excellent mechanical properties in terms of uniform elongation of 7.5%, yield ratio of 0.78, strain hardening exponent of 0.145, an impact energy of 286 J at - 10 deg. C and a shear area of 98% at 0 deg. C in the drop weight tear test. The tensile strength and impact energy of the weld metal didn't significantly reduce, because of the intragranularly nucleated acicular ferrites microstructure, leading to high strength and toughness in weld metal. The heat affected zone contained complete quenching zone and incomplete quenching zone, which exhibited excellent low temperature toughness of 239 J at - 10 deg. C. - Research Highlights: {yields}The pipe with ferrite/martensite microstructure shows high deformability. {yields}The base metal of the pipe consists of ferrite and martensite. {yields}Heat affected zone shows excellent low temperature toughness. {yields}Weld metal mainly consists of intragranularly nucleated acicular ferrites. {yields}Weld metal shows excellent low temperature toughness and high strength.

Li Rutao, E-mail: lrt851@126.com; Zuo Xiurong, E-mail: zuoxiurong@126.com; Hu Yueyue, E-mail: hucheng85@126.com; Wang Zhenwei, E-mail: wzw0530@126.com; Hu, Dingxu, E-mail: xiaohu369@163.com

2011-08-15

437

Some investigations on microstructure and mechanical properties of submerged arc welded HSLA steel joints  

Microsoft Academic Search

This paper investigates the influence of the submerged arc welding (SAW) process parameters (welding current and welding speed)\\u000a on the microstructure, hardness, and toughness of HSLA steel weld joints. Attempts have also been made to analyze the results\\u000a on the basis of the heat input. The SAW process was used for the welding of 16mm thick HSLA steel plates. The

Keshav Prasad; D. K. Dwivedi

2008-01-01

438

Variations in the microstructure and properties of Mn-Ti multiple-phase steel with high strength under different tempering temperatures  

NASA Astrophysics Data System (ADS)

There are few relevant researches on coils by tempering, and the variations of microstructure and properties of steel coil during the tempering process also remain unclear. By using thermo-mechanical control process(TMCP) technology, Mn-Ti typical HSLA steel coils with yield strength of 920 MPa are produced on the 2250 hot rolling production line. Then, the samples are taken from the coils and tempered at the temperatures of 220 C, 350 C, and 620 C respectively. After tempering the strength, ductility and toughness of samples are tested, and meanwhile microstructures are investigated. Precipitates initially emerge inside the ferrite laths and the density of the dislocation drops. Then, the lath-shaped ferrites begin to gather, and the retained austenite films start to decompose. Finally, the retained austenite films are completely decomposed into coarse and short rod-shape precipitates composed of C and Ti compounds. The yield strength increases with increasing tempering temperature due to the pinning effect of the precipitates, and the dislocation density decreases. The yield strength is highest when the steel is tempered at 220 C because of pinning of the precipitates to dislocations. The total elongation increases in all samples because of the development of ferrites during tempering. The tensile strength and impact absorbed energy decline because the effect of impeding crack propagation weakens as the retained austenite films completely decompose and the precipitates coarsen. This paper clarifies the influence of different tempering temperatures on phase transformation characteristics and process of Mn-Ti typical multiphase steels, as well as its resulting performance variation rules.

Li, Dazhao; Li, Xiaonan; Cui, Tianxie; Li, Jianmin; Wang, Yutian; Fu, Peimao

2015-01-01

439

Electrochemical properties of 316L stainless steel with culturing L929 fibroblasts  

PubMed Central

Potentiodynamic polarization and impedance tests were carried out on 316L stainless steel with culturing murine fibroblast L929 cells to elucidate the corrosion behaviour of 316L steel with L929 cells and to understand the electrochemical interface between 316L steel and cells, respectively. Potential step test was carried out on 316L steel with type I collagen coating and culturing L929 cells to compare the effects of collagen and L929 cells. The open-circuit potential of 316L steel slightly shifted in a negative manner and passive current density increased with cells, indicating a decrease in the protective ability of passive oxide film. The pitting potential decreased with cells, indicating a decrease in the pitting corrosion resistance. In addition, a decrease in diffusivity at the interface was indicated from the decrease in the cathodic current density and the increase in the diffusion resistance parameter in the impedance test. The anodic peak current in the potential step test decreased with cells and collagen. Consequently, the corrosion resistance of 316L steel decreases with L929 cells. In addition, collagen coating would provide an environment for anodic reaction similar to that with culturing cells. PMID:16849246

Hiromoto, Sachiko; Hanawa, Takao

2005-01-01

440

Study on mechanical properties of steel honeycomb panel three-point bending specimen under in-plane and out-plane transverse dynamic impact load  

NASA Astrophysics Data System (ADS)

The metal honeycomb material has high strength and high stiffness, as a high-performance sandwich panel, it is an ideal lightweight structural material, and widely used in aviation, aerospace, shipbuilding and other fields. In this paper, the improved SHPB instrument is used for testing the in-plane and out-plane mechanical properties of the steel honeycomb panel three-point bending specimen, and also compare the results with the static in-plane and out-plane three-point bending experiments results which is tested by the INSTRON 4505 electronic universal testing machine, and then study the mechanical properties of the steel honeycomb panel three-point bending specimen under transverse dynamic impact load. From the results it can be see that, for the out-plane three point bending experiment, L direction mechanical properties is better than the W direction, and the honeycomb core play an important role during the specimen deformation, while for the in-plane three point bending experiment, the honeycomb core mechanical role is not distinctness.

Zou, Guangping; Chang, Zhongliang; Xia, Xingyou; Zhang, Xueyi

2009-12-01

441

Study on mechanical properties of steel honeycomb panel three-point bending specimen under in-plane and out-plane transverse dynamic impact load  

NASA Astrophysics Data System (ADS)

The metal honeycomb material has high strength and high stiffness, as a high-performance sandwich panel, it is an ideal lightweight structural material, and widely used in aviation, aerospace, shipbuilding and other fields. In this paper, the improved SHPB instrument is used for testing the in-plane and out-plane mechanical properties of the steel honeycomb panel three-point bending specimen, and also compare the results with the static in-plane and out-plane three-point bending experiments results which is tested by the INSTRON 4505 electronic universal testing machine, and then study the mechanical properties of the steel honeycomb panel three-point bending specimen under transverse dynamic impact load. From the results it can be see that, for the out-plane three point bending experiment, L direction mechanical properties is better than the W direction, and the honeycomb core play an important role during the specimen deformation, while for the in-plane three point bending experiment, the honeycomb core mechanical role is not distinctness.

Zou, Guangping; Chang, Zhongliang; Xia, Xingyou; Zhang, Xueyi

2010-03-01

442

Validation of a small punch testing technique to characterize the cryogenic fracture properties of austenitic stainless steel welds  

NASA Astrophysics Data System (ADS)

This study was performed to demonstrate the feasibility of performing liquid helium temperature (4 K) small punch (SP) tests on austenitic stainless steel weld for Large Helical Device (LHD) superconducting magnets. The SP specimens (10100.5 mm) were prepared from the different locations of electron-beam weld in type 316 stainless steel to examine the variation of the fracture properties in the weld and its heat affected zone. Previously proposed correlations for SP and elastic-plastic fracture toughness test methods were applied to predict a SP test-based fracture toughness from equivalent fracture strain. The correlation was also found between the room temperature Vickers hardness of the heat affected zone and its fracture toughness at 4 K. A finite element analysis was performed to convert the experimentally measured load-displacement data into useful engineering information. The maximum strain energy density was calculated and correlated with equivalent fracture strain.

Horiguchi, K.; Shindo, Y.

2002-05-01

443

Evolution of structure and properties of VVER-1000 RPV steels under accelerated irradiation up to beyond design fluences  

NASA Astrophysics Data System (ADS)

In this paper comprehensive studies of structure and properties of VVER-1000 RPV steels after the accelerated irradiation to fluences corresponding to extended lifetime up to 60 years or more as well as comparative studies of materials irradiated with different fluxes were carried out. The significant flux effect is confirmed for the weld metal (nickel concentration ?1.35%) which is mainly due to development of reversible temper brittleness. The rate of radiation embrittlement of VVER-1000 RPV steels under operation up to 60 years and more (based on the results of accelerated irradiation considering flux effect for weld metal) is expected not to differ significantly from the observed rate under irradiation within surveillance specimens.

Gurovich, B.; Kuleshova, E.; Shtrombakh, Ya.; Fedotova, S.; Maltsev, D.; Frolov, A.; Zabusov, O.; Erak, D.; Zhurko, D.

2015-01-01