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1

Improvement in high stress abrasive wear property of steel by hardfacing  

SciTech Connect

High stress abrasive wear behavior of mild steel, medium carbon steel, and hardfacing alloy has been studied to ascertain the extent of improvement in the wear properties after hardfacing of steel. High stress abrasive wear tests were carried out by sliding the specimen against the abrasive media consisting of silicon carbide particles, rigidly bonded on paper base and mounted on disk. Maximum wear was found in the case of mild steel followed by a medium carbon alloy steel and a hardfacing alloy. Different compositions of steels and constituent phases present led to different wear rates of the specimen. The extent of improvement in wear performance of steel due to hardfacing is quite appreciable (twice compared to mild steel). Microstructural examination of the wear surface has been carried out to understand the wear mechanism.

Kumar, S.; Mondal, D.P.; Khaira, H.K.; Jha, A.K.

1999-12-01

2

Evaluation of temperature and properties at interface of AISI 1040 steels joined by friction welding  

Microsoft Academic Search

Purpose – The purpose of this paper is to evaluate temperature and properties at interface of AISI 1040 steels joined by friction welding. Design\\/methodology\\/approach – In this study, AISI 1040 medium carbon steel was used in the experiments. Firstly, optimum parameters of the friction welding were obtained by using a statistical analysis. Later, the microstructures of the heat-affected zone are

Hilmi Kuscu; Ismail Becenen; Mumin Sahin

2008-01-01

3

Microstructure and wear property of carbon nanotube carburizing carbon steel by laser surface remelting  

Microsoft Academic Search

Carbon nanotube was used to carburize the surface of medium carbon steel and mild steel, respectively, by means of laser surface remelting. The slurry of carbon nanotube of ethanol was coated on the surface of the materials prior to laser irradiation. Microstructures, microhardness and wear property of the surface layers treated by different laser performance parameters were studied. Graphite coating

Jianhua Yao; Qunli Zhang; Mingxia Gao; Wei Zhang

2008-01-01

4

Microstructure and property changes caused by diffusion during CVD coating of steels  

Microsoft Academic Search

The interdiffusion of carbon and titanium between a substrate and coating during chemical vapor deposition (CVD) coating of steels influences the microstructures and properties of the coating\\/substrate compounds. The CVD parameters atmosphere, temperature and pressure as well as the composition of the steel substrates were investigated systematically to optimize the properties of the coating\\/substrate compounds. The tool and carbon steels

O. H. Kessler; F. T. Hoffmann; P. Mayr

1999-01-01

5

Frication Property of Mo-Cr-Infiltrated Steel Layer by Plasma Surface Metallurgy  

NASA Astrophysics Data System (ADS)

Introduced in this article is the technique to acquire a high performance strengthened layer on carbon steel samples, namely, plasma alloying on the surface of Q235 steel and heat treatment technology. With this technique the alloying elements of Mo, Cr, and C can be obtained on the surface of Q235 steel samples. The content of the constituent elements is approximately up to high speed steels (HSS). The surface property required for the HSS after hardening and low tempering is attained. In the test, the alloying elements Mo and Cr were penetrated into the Q235 steel samples by glow discharge sputtering so that the content of the alloyed layer on the surface of the Q235 steel samples was about 20% Mo and 10% Cr. Two kinds of experiments were conducted. One was to carry out ultra-saturated carburization. The alloyed layer's composition was similar to molybdenum HSS with surface carburizing of more than 2.0%. The carbides of the alloyed layer were compact, uniform and disperse without a coarse eutectic ledeburite structure. The another was ion nitriding after the alloying elements of Mo and Cr were penetrated. The first process included hardening with low tempering and hardening with cryogenic treatment for 2 hr and low tempering. The second one was ion nitriding only. It was found that the surface hardness after cryogenic treatment is up to 1600 HV, much higher than that without cryogenic treatment. The abrasion test results indicate that, without the penetrated alloy elements Mo and Cr and without cryogenic treatment and ion nitriding, the friction coefficient is lower by one order of magnitude. The change in relative resistance is similar to the change in the friction coefficient, but without a proportional relationship.

Xu, Jinyong; Kang, Zhicheng; Liu, Yanping; Wang, Jianzhong; Gao, Yuan; Xu, Zhong

2006-07-01

6

Nanoscale steel-brass multilayer laminates made by cold rolling: Microstructure and tensile properties  

SciTech Connect

The thrust of this study is to fabricate steel-brass multilayer laminates with layer thicknesses in the nanometer range and to evaluate their mechanical properties. Repeated cold rolling of multilayer stacks was adopted to produce the laminates, because the relative simplicity and the low-cost nature of this process can allow the scaling-up of the technique to the level of commercial-scale production. This work is a continuation of a previous study, in which steel-brass laminates with layer thicknesses in the micrometer range were fabricated for the first time and their tensile properties were evaluated. The present work, however, emphasizes making multilayers with layer thicknesses in the nanometer range and evaluating their mechanical properties. The dependence of strength and ductility on the layer spacing in the nanometer range, is highlighted. It is shown that strength levels comparable to quenched and tempered low alloy steels can be achieved in the laminates by rolling down to the low end of nanometer range. The relevant strengthening mechanisms are also discussed.

Kavarana, F.H.; Ravichandran, K.S.; Sahay, S.S.

2000-05-10

7

Properties of high nitrogen steels produced by high pressure gas atomization  

SciTech Connect

The production of metal powder by gas atomization typically combines melting at ambient pressure and atomization through high pressure gas jet nozzles into an atomization chamber, also at ambient pressure. To achieve high nitrogen contents, a series of Fe-Cr-Mn-Ni steels were melted under nitrogen pressures of 150 psi and atomized with nitrogen gas into an atomizing chamber held at 100 psi. A small scale atomizing unit (charge size 300 lbs) was modified to achieve the desired production characteristics. High nitrogen steels produced by high pressure gas atomization exceeded the atmospheric solubility limit of nitrogen by as much as 500% and nitrogen contents between 0.5 to 1.3 wt. pct. was achieved. Three Fe-Cr-Mn-Ni alloys each different nitrogen contents were atomized and consolidated by hot-extrusion. The microstructure and tensile properties were evaluate and correlated to conditions during atomization, extrusion and final nitrogen content.

Dunning, John S.

2000-10-01

8

Antibacterial properties and corrosion resistance of AISI 420 stainless steels implanted by silver and copper ions  

NASA Astrophysics Data System (ADS)

Silver or copper ions are often chosen as antibacterial agents. But a few reports are concerned with these two antibacterial agents for preparation of antibacterial stainless steel (SS). The antibacterial properties and corrosion resistance of AISI 420 stainless steel implanted by silver and copper ions were investigated. Due to the cooperative antibacterial effect of silver and copper ions, the Ag/Cu implanted SS showed excellent antibacterial activities against both Gram-negative Escherichia coli ( E. coli) and Gram-positive Staphylococcus aureus ( S. aureus) at a total implantation dose of 2×1017 ions/cm2. Electrochemical polarization curves revealed that the corrosion resistance of Ag/Cu implanted SS was slightly enhanced as compared with that of un-implanted SS. The implanted layer was characterized by X-ray photoelectron spectroscopy (XPS). Core level XPS spectra indicate that the implanted silver and copper ions exist in metallic state in the implanted layer.

Ni, Hong-wei; Zhang, Han-shuang; Chen, Rong-sheng; Zhan, Wei-ting; Huo, Kai-fu; Zuo, Zhen-yu

2012-04-01

9

Microstructure and wear property of carbon nanotube carburizing carbon steel by laser surface remelting  

NASA Astrophysics Data System (ADS)

Carbon nanotube was used to carburize the surface of medium carbon steel and mild steel, respectively, by means of laser surface remelting. The slurry of carbon nanotube of ethanol was coated on the surface of the materials prior to laser irradiation. Microstructures, microhardness and wear property of the surface layers treated by different laser performance parameters were studied. Graphite coating was also used for carburizing. The results showed that both carbon nanotube and graphite were dissolved in the surface molten layer, leading a carburized hardening layer on the surface of the substrate. However, different microstructures formed in the carburizing layers, depending mainly on the type of carburization materials, carbon nanotube or graphite. The carbon nanotube hardening layer exhibits a little higher hardness than the graphite hardening layer. The carburized layer greatly increases the wear resistance of the base material.

Yao, Jianhua; Zhang, Qunli; Gao, Mingxia; Zhang, Wei

2008-08-01

10

Improvement of mechanical properties on metastable stainless steels by reversion heat treatments  

NASA Astrophysics Data System (ADS)

AISI 301LN is a metastable austenitic stainless steel that offers an excellent combination of high strength and ductility. This stainless grade is currently used in applications where severe forming operations are required, such as automotive bodies. When these metastable steels are plastically deformed at room temperature, for example by cold rolling, austenite transforms to martensite and, as a result, yield strength increases but ductility is reduced. Grain refinement is the only method that allows improving strength and ductility simultaneously. Several researchers have demonstrated that fine grain AISI 301LN can be obtained by heat treatment after cold rolling. This heat treatment is called reversion because it provokes the reversion of strain induced martensite to austenite. In the present work, sheets of AISI 301LN previously subjected to 20% of cold rolling reduction were treated and a refined grain austenitic microstructure was obtained. Mechanical properties, including fatigue limit, were determined and compared with those corresponding to the steel both before and after the cold rolling.

Mateo, A.; Zapata, A.; Fargas, G.

2013-12-01

11

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

12

Fatigue properties of a biomedical 316L steel processed by surface mechanical attrition  

NASA Astrophysics Data System (ADS)

This work deals with the influence of surface mechanical attrition treatment (SMAT) on fatigue properties of a medical grade 316L stainless steel. Metallurgical parameters governed by SMAT such as micro-hardness and nanocrystalline layer are characterized using different techniques. Low cycle fatigue tests are performed to investigate the fatigue properties of untreated and SMAT-processed samples. The results show that the stress amplitude of SMAT- processed samples with two different treatment intensities is significantly enhanced compared to untreated samples, while the fatigue strength represented by the number of cycles to failure is not improved in the investigated strain range. The enhancement in the stress amplitude of treated samples can be attributed to the influence of the SMAT affected layer.

Sun, Z.; Chemkhi, M.; Kanoute, P.; Retraint, D.

2014-08-01

13

Modifications of mechanical and electrochemical properties of stainless steel surfaces by laser shock processing  

NASA Astrophysics Data System (ADS)

Laser Shock Processing (LSP) consists on focusing a high energy pulsed laser beam on metals to create shock waves and thereby, generate compressive stresses. These stress are similar to those of conventional mechanical treatments like short peening. Nevertheless, at LSP the affected depths are greater and the surfaces keep their roughness and hardness. The present study compare the effects of LSP on the surface mechanical properties of two stainless steels: an austenitic (AISI 316L) and a martensitic (Z12 CNDV 12.02). The surface effects are characterized in terms of microstructure, hardening and residual stress levels (measured by X-ray diffraction technique). The effects of LSP on the pitting corrosion resistance of the martensitic stainless steel in a NaCl 0.01 M + Na2SO4 0.01 M solution are presented. Electrochemical tests were carried out by using open circuit and polarization techniques, to determine electrochemical parameters (free and pitting potentials, passive current densities). Laser-induced work-hardening effects were shown to be more important in the case of 316 L for which they strongly depend on the impacts repetition and the laser power density. Significant modifications on localized corrosion properties were noticed for each treatment condition (8 GW/cm2 - 20 ns pulses and 40 GW/cm2 - 2,3 ns pulses) i.e. pitting potentials were not modified but free potentials were shifted to anodic values and passive current densities reduced.

Scherpereel, Xavier; Peyre, Patrice; Fabbro, Remy; Lederer, Glenn; Celati, N.

1997-08-01

14

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.; Hähner, P.

2012-09-01

15

The effect of ultrasonics on the strength properties of carbon steel processed by cold plastic deformation  

NASA Technical Reports Server (NTRS)

A study was made of the influence of ultrasounds on the mechanical properties of OLT 35 carbon steel tubes cold-drawn on a plug ultrasonically activated by longitudinal waves. Experimental results indicate that: 1. The reduction in the values of the flow limit and tensile strength is proportional to the increase in acoustic energy introduced into the material subjected to deformation. 2. The diminution in influence of ultrasounds on tensile strength and flow rate that is due to an increased degree of deformation is explained by a reduction in specific density of the acoustic energy at the focus of deformation. 3. The relations calculated on the basis of the variation in the flow limit and tensile strength as a function of acoustic energy intensity was verified experimentally.

Atanasiu, N.; Dragan, O.; Atanasiu, Z.

1974-01-01

16

Properties and potential for application of steel reinforced polymer and steel reinforced grout composites  

Microsoft Academic Search

The paper introduces steel reinforced polymer (SRP) and steel reinforced grout (SRG) composites that are considered for application in civil engineering for bridge and concrete buildings upgrade. These composites consist of steel cords formed by interwoven steel wires embedded within a polymer resin or cementitious grout matrix. The properties of SRP are evaluated experimentally and compared to micromechanical equations to

X. Huang; V. Birman; A. Nanni; G. Tunis

2005-01-01

17

Mechanical Properties of Bulk Nanocrystalline Austenitic Stainless Steels Produced by Equal Channel Angular Pressing  

E-print Network

rapid in 316 L SS than that in 304L. Also the structures are shown to retain a predominant austenite phase. Hardness increases by a factor of about 2.5 in both steels due largely to grain refinement and an introduction of a high density of dislocations...

Gonzalez, Jeremy

2012-10-19

18

Elastic property maps of austenitic stainless steels.  

PubMed

The most recent advances in theory and methodology are directed towards obtaining a quantitative description of the electronic structure and physical properties of alloy steels. Specifically, we employ ab initio alloy theories to map the elastic properties of austenitic stainless steels as a function of chemical composition. The so generated data can be used in the search for new steel grades, and, as an example, we predict two basic compositions with outstanding properties among the austenitic stainless steels. PMID:11955203

Vitos, L; Korzhavyi, P A; Johansson, B

2002-04-15

19

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

20

Microstructure and tribological properties of stainless steel coatings sprayed by two methods based on spraying  

Microsoft Academic Search

In this work, the microstructure and sliding wear behaviors of stainless steel (AISI 420) coatings prepared by electro-thermal explosion directional spraying (EEDS) and high velocity arc spraying (HVAS) were comparatively investigated. Results show that the EEDS coatings possess more compact microstructure, higher nano-hardness and nano-elastic modulus, finer bond and better wear resistance than the HVAS coatings. The dominant wear mechanism

Guo Jin; Bin-shi Xu; Hai-dou Wang; Qing-fen Li; Shi-cheng Wei

2007-01-01

21

Characterization of a boron alloyed 9Cr3W3CoVNbBN steel and further improvement of its high-temperature mechanical properties by thermomechanical treatments  

NASA Astrophysics Data System (ADS)

In the framework of the development of Generation IV nuclear reactors and fusion nuclear reactors, materials with an improved high temperature (?650 °C) mechanical strength are required for specific components. The 9-12% Cr martensitic steels are candidate for these applications. Previous works showed that the application of a thermomechanical treatment, including warm-rolling in metastable austenitic phase, to the commercial Grade 91 martensitic steel, allowed refining its microstructure, improving its precipitation state and its mechanical properties (hardness, tensile and creep properties). In the present paper, experimental steel called NPM, designed for good high-temperature creep resistance, is evaluated in terms of microstructure and mechanical properties, and compared to the G91 steel. Then the developed thermomechanical treatment is applied to this steel. Its microstructure is refined and its hardness and tensile properties are much better than the as-received NPM and therefore than the G91 steel. The cyclic softening effect still occurs for the optimized NPM, but this material once softened by cyclic loadings, still presents better creep properties than the as-received NPM steel, and even more than the commercial G91 steel.

Hollner, S.; Piozin, E.; Mayr, P.; Caës, C.; Tournié, I.; Pineau, A.; Fournier, B.

2013-10-01

22

Nanocrystalline structures and tensile properties of stainless steels processed by severe plastic deformation  

NASA Astrophysics Data System (ADS)

The development of nanocrystalline structures in austenitic stainless steels during large strain cold rolling and their tensile behavior were studied. The cold rolling to total equivalent strains above 2 was accompanied by the evolution of nanocrystalline structures with the transverse grain size of about 100 nm. The development of deformation twinning and martensitic transformation during cold working promoted the fast kinetics of structural changes. The development of nanocrystalline structures resulted in significant strengthening. More than fourfold increase in the yield strength was achieved. The strengthening of nanocrystalline steels after severe plastic deformation was considered as a concurrent operation of two strengthening mechanisms, which were attributed to grain size and internal stress. The contribution of internal stresses to the yield strength is comparable with that from grain size strengthening.

Belyakov, A.; Odnobokova, M.; Kipelova, A.; Tsuzaki, K.; Kaibyshev, R.

2014-08-01

23

Tensile Properties of Austenitic Stainless Steel  

E-print Network

; The choices we make, not the chances we take, determine our destiny. #12; Preface This dissertation 2002. This dissertation contains less than 15,000 words. Except where acknowledgement and reference; Abstract The short­term mechanical properties of austenitic stainless steels can be affected by a myriad

Cambridge, University of

24

Tensile Properties of Austenitic Stainless Steel  

E-print Network

choices we make, not the chances we take, determine our destiny. #12;Preface This dissertation 2002. This dissertation contains less than 15,000 words. Except where acknowledgement and reference;Abstract The short-term mechanical properties of austenitic stainless steels can be affected by a myriad

Cambridge, University of

25

Frication Property of Mo-Cr-Infiltrated Steel Layer by Plasma Surface Metallurgy  

Microsoft Academic Search

Introduced in this article is the technique to acquire a high performance strengthened layer on carbon steel samples, namely, plasma alloying on the surface of Q235 steel and heat treatment technology. With this technique the alloying elements of Mo, Cr, and C can be obtained on the surface of Q235 steel samples. The content of the constituent elements is approximately

Jinyong Xu; Zhicheng Kang; Yanping Liu; Jianzhong Wang; Yuan Gao; Zhong Xu

2006-01-01

26

Stainless steel surface alloying process with molybdenum or ruthenium by high-energy excimer laser: structural, electrochemical, and corrosion properties  

NASA Astrophysics Data System (ADS)

Chemical transformations on stainless steel surfaces (304 AISI) are obtained by melting with an excimer laser. The very high quenching rate allows to create a thin continuous metastable gradient in composition and structure by opposition to other melting techniques which promote multiphase layer. The mechanical properties of the bulk are maintained and the external layer is chemically modified for a better resistance to environmental aggressivity. Molybdenum is used for corrosion protection and ruthenium for cathodic and anodic properties. The composition is analyzed on cross-sections obtained by ultramicrotomy. A continuous gradient approximately 500 nm (nanometer) of Mo or Ru with decreasing grain size (< 0,3 micrometer compared to 10 - 20 micrometers for 304 AISI) is observed. Mo and Ru surface alloys show an important beneficial effect from cathodic and transpassive potential range.

Beaunier, Luc; Pasquier, Christian; Pillier, Francoise; Laurens, Patricia

1997-08-01

27

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

28

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.; Westkämper, G.; Angerer, R.

1999-12-01

29

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

30

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

31

Effect of cathodic hydrogenation on the mechanical properties of AISI 304 stainless steel nitrided by ion implantation, glow discharge and plasma immersion ion implantation  

NASA Astrophysics Data System (ADS)

Hydrogen embrittlement in austenitic stainless steels is restricted to the surface due to the low hydrogen diffusion in austenitic structures. The effect of three different nitriding processes: ion implantation (II), plasma immersion ion implantation (PI3) and glow discharge (GD), on the mechanical and structural properties of cathodically hydrogenated AISI 304 stainless steel were studied in the present work. Cathodic hydrogenation was made on untreated and nitrided samples. Surface microstructure after nitriding and hydrogenation was investigated by X-ray diffraction. Mechanical properties were measured by instrumented indentation. Surface crack formation and hardness decrease was observed in non-nitrided samples after cathodic hydrogenation. Hardness of nitrided samples decreases after hydrogen degassing but still has values higher than untreated samples. Comparative analysis of nitriding processes and working conditions indicated that glow discharge plasma nitriding process at 400 °C or 450 °C is the most adequate to avoid crack formation in steel surface after cathodic hydrogenation.

Foerster, C. E.; Souza, J. F. P.; Silva, C. A.; Ueda, M.; Kuromoto, N. K.; Serbena, F. C.; Silva, S. L. R.; Lepienski, C. M.

2007-04-01

32

Properties of Composite Borided Layers on Steel Produced by Combined Surface Treatments  

Microsoft Academic Search

With the increasing progress in engineering a growing need has been felt for materials that show improved surface properties, such as an increased resistance to wear and corrosion. A new method combining the known techniques of chemical and electrochemical nickel plating and plasma bonding is discussed. The paper presents properties of such produced composite and multicomponent borided layers.

T. Wierzchon; P. Bielinski

1995-01-01

33

Improving the mechanical properties of 17-4PH stainless steel by low temperature plasma surface treatment  

Microsoft Academic Search

17-4PH stainless steel was plasma nitrocarburized at low temperature for improving its mechanical properties. The results show that the modified layer thicknesses increase with increasing treatment time and the layers growth approximately conforms to the parabolic law. The phases in the modified layers are mainly of incipient ??-Fe4N and ??-Fe with amorphous characterization, and then changed into ??-Fe4N, ??N and

M. F. Yan; R. L. Liu; D. L. Wu

2010-01-01

34

Properties of HIPed stainless steel powder  

Microsoft Academic Search

In the current design of ITER primary wall, 316LN stainless steel is the reference structural material. Austenitic stainless steel is used for water-cooling channels and structures. As material data on hot isostatic pressed (HIP) 316LN were not available in open literature and from powder producers, the main properties of unirradiated samples have been measured in CEA\\/CEREM. Fully dense material without

Ch. Dellis; G. Le Marois; J. M. Gentzbittel; G. Robert; F. Moret

1996-01-01

35

Improvement of mechanical and tribological properties in steel surfaces by using titanium-aluminum/titanium-aluminum nitride multilayered system  

NASA Astrophysics Data System (ADS)

Improvement of mechanical and tribological properties on AISI D3 steel surfaces coated with [Ti-Al/Ti-Al-N]n multilayer systems deposited in various bilayer periods (?) via magnetron co-sputtering pulsed d.c. method, from a metallic binary target; has been studied in this work exhaustively. The multilayer coatings were characterized in terms of structural, chemical, morphological, mechanical and tribological properties by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscopy, nanoindentation, pin-on-disc and scratch tests, respectively. The failure mode mechanisms were studied by optical microscopy. Results from X-ray diffraction analysis revealed that the crystal structure of TiAl/TiAlN multilayer coatings has a tetragonal and FCC NaCl-type lattice structures for Ti-Al and Ti-Al-N, respectively, i.e., it was found to be non-isostructural multilayers. An enhancement of both hardness and elastic modulus up to 29 GPa and 260 GPa, respectively, was observed as the bilayer periods (?) in the coatings were decreased. The sample with a bilayer period (?) of 25 nm and bilayer number n = 100 showed the lowest friction coefficient (?0.28) and the highest critical load (45 N), corresponding to 2.7 and 1.5 times better than those values for the coating deposited with n = 1, respectively. These results indicate an enhancement of mechanical, tribological and adhesion properties, comparing to the [Ti-Al/Ti-Al-N]n multilayer systems with 1 bilayer at 26%, 63% and 33%, respectively. This enhancement in hardness and toughness for multilayer coatings could be attributed to the different mechanisms for layer formation with nanometric thickness such as the novel Ti-Al/Ti-Al-N effect and the number of interfaces that act as obstacles for the crack deflection and dissipation of crack energy.

Ipaz, L.; Caicedo, J. C.; Esteve, J.; Espinoza-Beltran, F. J.; Zambrano, G.

2012-02-01

36

Thermophysical property sensitivity effects in steel solidification  

NASA Technical Reports Server (NTRS)

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

Overfelt, Tony

1993-01-01

37

Study of the effect of nano-sized precipitates on the mechanical properties of boron-added low-carbon steels by neutron scattering techniques  

PubMed Central

Small-angle neutron scattering (SANS) and neutron powder diffraction (ND) techniques were used to study quantitatively the effect of nano-sized precipitates and boron addition on the mechanical properties of low-carbon steels. SANS was used to evaluate nano-sized precipitates, smaller than about 600?Å in diameter, and ND was used to determine the weight fraction of the cementite precipitates. Fine core–shell structured spherical precipitates with an average radius of ~50?Å, such as MnS and/or CuS, surrounded by BN layers were observed in the boron-added (BA) low-carbon steels; fine spherical precipitates with an average radius of ~48?Å were mainly observed in the boron-free (BF) low-carbon steels. In the BA steels, the number of boron precipitates, such as BN, Fe3(C,B) and MnS, surrounded by BN layers increased drastically at higher hot-rolling temperatures. The volume fraction of the fine precipitates of the BA steels was higher than that of the BF steels; this difference is related to the rapid growth of the BN layers on the MnS and CuS precipitates. Boron addition to low-carbon steels resulted in a reduction in strength and an improvement in elongation; this behaviour is related to the reduction of the solute carbon and the nitrogen contents in the ferrite matrix caused by the precipitation of BN, as well by the increase in the volume fraction of the cementites. PMID:19461851

Seong, B. S.; Cho, Y. R.; Shin, E. J.; Kim, S. I.; Choi, S.-H.; Kim, H. R.; Kim, Y. J.

2008-01-01

38

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

39

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

40

Influence of prestrain history on fracture toughness properties of steels  

NASA Astrophysics Data System (ADS)

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 of cyclic prestrain on fracture behavior of 4340 steel and 316 stainless steel were found to be related to cyclic softening and cyclic hardening characteristics, respectively. Moreover, material strengths rationalized the influence of prestrain history on fracture toughness properties of these two steels.

Liaw, P. K.; Landes, J. D.

1986-03-01

41

PROPERTIES OF URANIUM DIOXIDE-STAINLESS STEEL DISPERSION FUEL PLATES  

Microsoft Academic Search

The physical and mechanical properties of GCRE-type fuel elements were ;\\u000a determined from room temperature to 1650 deg F. The fuel elements were prepared ;\\u000a by cladding Type 318 stainless steel sheet to a core containing 15 to 35 wt.% UO\\/;\\u000a sub 2\\/ in either prealloyed Type 318 stainless steel or elemental iron-18 wt.% ;\\u000a chromium-14 wt. % nickel-2.5 wt.

S. J. Paprocki; D. L. Keller; J. M. Fackelmann

1959-01-01

42

Mechanical properties of steels after vacuum and gas carburizing  

Microsoft Academic Search

1.After heating to 1100°C and subsequent phase recrystallization to cycles making it possible to obtain an approximately 2 mm case depth in vacuum carburizing the mechanical properties (st, sy, ?, d) of the investigated steel and also the impact strengtha1 do not drop with the exception ofa1, of 20Kh steel, which decreases by 6.7% after heating at 1100°C for 2h.2.The

A. G. Goncharov; R. P. Uvarova

1990-01-01

43

Microstructure and mechanical properties of an ODS RAF steel fabricated by hot extrusion or hot isostatic pressing  

Microsoft Academic Search

Ingots of an oxide dispersion strengthened reduced activation ferritic steel with the Fe–14Cr–2W–0.3Ti–0.3Y2O3 chemical composition (in wt.%) were synthesized by mechanical alloying of elemental powders with 0.3wt.% Y2O3 particles in a planetary ball mill, in a hydrogen atmosphere, and compacted by either hot extrusion or hot isostatic pressing. The microstructures of the obtained materials were characterized by means of light

P. Unifantowicz; Z. Oksiuta; P. Olier; Y. de Carlan; N. Baluc

2011-01-01

44

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

45

The microstructure and properties of 17-4PH martensitic precipitation hardening stainless steel modified by plasma nitrocarburizing  

Microsoft Academic Search

17-4PH martensitic precipitation hardening stainless steel was plasma nitrocarburized at 430°C and 460°C for 8h. The nitrocarburized layers were characterized by optical microscope, scanning electron microscope, X-ray diffractometer, microhardness tests, pin-on-disc tribometer and the anodic polarization method in a 3.5% NaCl solution. The results show that the microstructure of plasma nitrocarburized layer is characterized by a compound layer with no

R. L. Liu; M. F. Yan

2010-01-01

46

Structure and properties of ion-nitrided stainless steels  

Microsoft Academic Search

The structure and properties of ion-nitrided layers on several stainless steels, 410 martensitic stainless steel, 430 ferritic stainless steel and 321 austenitic stainless steel, has been studied under varying process conditions with microhardness-depth correlations, optical microscopy and transmission electron microscopy. The process variables studied include time (2 to 10 h) and temperature (400 to 600° C). The highest case depth

K. Ozbaysal; O. T. Inal

1986-01-01

47

Mechanical properties of ferrite-perlite and martensitic Fe-Mn-V-Ti-C steel processed by equal-channel angular pressing and high-temeperature annealing  

NASA Astrophysics Data System (ADS)

Using the method of equal-channel angular pressing (ECAP), submicrocrystalline structure is formed in lowcarbon Fe-Mn-V-Ti-C steel with the average grain size 260 nm in the ferrite-perlite state and 310 nm in the martensitic state. It is established that the ECAP treatment gives rise to improved mechanical properties (H? = 2.9 GPa, ?0 = 990 MPa in the ferrite-perlite and H? = 3.7 GPa, ?0 = 1125 MPa in martensitic states), decreased plasticity, and results in plastic flow localization under tensile loading. The high strength properties formed by the ECAP are shown to sustain up to the annealing temperature 500°C.

Zakharova, G. G.; Astafurova, E. G.; Tukeeva, M. S.; Naidenkin, E. V.; Raab, G. I.; Dobatkin, S. V.

2011-09-01

48

Tensile properties of austenitic stainless steels and their weld joints after irradiation by the ORR-spectrally-tailoring experiment  

NASA Astrophysics Data System (ADS)

Tensile specimens of the Japanese heat of PCA (JPCA) and type 316 stainless steels were irradiated in spectrally tailored capsules in the Oak Ridge Research Reactor (ORR) to a peak dose of 7.4 dpa and a peak helium level of 105 appm in the temperature range between 328 and 673 K. Specimens of type 316 steel with weld joints produced by tungsten inert gas (TIG) and electron beam (EB) welding techniques were also included. Irradiation caused both increases in flow stress and decreases in elongation. Weld joint specimens exhibited both lower strength and elongation after irradiation. The reduction of area (RA) for the TIG weld joint specimens decreased by a factor of 5 compared to unirradiated base metal specimens, however, they still fractured in a ductile mode. The EB weld joints maintained RA levels similar to that of the unirradiated base metal specimens. Post-radiation ductilities of weld joints and base metal specimens of these steels should be adequate for their application to next generation fusion experimental devices, such as the International Tokamak Experimental Reactor (ITER).

Jitsukawa, S.; Maziasz, P. J.; Ishiyama, T.; Gibson, L. T.; Hishinuma, A.

1992-09-01

49

Microstructure and mechanical properties of ?-particle irradiated stainless steels  

NASA Astrophysics Data System (ADS)

The effect of helium injected in stainless steels on the mechanical properties are investigated. The materials used are 100 ?m thick foils of type 316 austenitic stainless steel, dual phase (9Cr-2Mo, ferritic and martensitic phase) stainless steel and duplex (22Cr-5Ni, ferritic and austenitic phase) stainless steel. The tensile strength (0.2% proof strength and ultimate strength in room temperature tensile test) of these materials increased slightly with the amount of injected alpha particles, but the elongation of these steels decreased with the alpha particle dose. Intergranular type fracture was observed only on the 316 stainless steel in which alpha particles had been injected in amounts up to 1.3 × 10 17 cm -2 at the depth of range. Transgranular fracture occurred on a post-injection annealed 316 stainless steel and on the other materials. The transmission electron microscope observation of helium bubble distribution established that the intergranular fracture is caused by a highly dense distribution of small helium bubbles at grain boundaries.

Igata, N.; Miyahara, K.; Tada, C.; Blasl, D.; Hamada, S.; Sawai, T.; Kayano, H.; Hosoi, Y.

1986-11-01

50

Correlation of Microstructure, Chip-Forming Properties, and Dynamic Torsional Properties in Free-Machining Steels  

NASA Astrophysics Data System (ADS)

Four free-machining steels were fabricated by varying volume fractions of MnS and soft metal additives of Pb and Bi, and their microstructures, tensile properties, chip-forming properties, and dynamic torsional properties were analyzed. Machining and dynamic torsional tests were conducted on the four steels to investigate chip-forming and dynamic torsional properties, respectively. In the Pb-S- and Bi-S-based steels, the chip thickness and ridge area of the 1st chip obtained from the machining test were smaller than in the S-based steels and were not changed much after repeated machining processes. These chip-forming properties were closely related with dynamic torsional properties. Dynamic maximum shear strains of the Pb-S- and Bi-S-based steels were higher than those of the S-based steels, while dynamic maximum shear stresses were lower, thereby leading to the relatively homogeneous dynamic shear deformation and to the better chip-forming properties and machinability.

Kim, Yongjin; Kim, Hyunmin; Kang, Minju; Rhee, Kiho; Shin, Sang Yong; Lee, Sunghak

2013-10-01

51

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

52

Properties of HIPed stainless steel powder  

NASA Astrophysics Data System (ADS)

In the current design of ITER primary wall, 316LN stainless steel is the reference structural material. Austenitic stainless steel is used for water-cooling channels and structures. As material data on hot isostatic pressed (HIP) 316LN were not available in open literature and from powder producers, the main properties of unirradiated samples have been measured in CEA/CEREM. Fully dense material without any porosity is obtained when appropriate HIP parameters are applied. Microstructural examination and mechanical properties are confirmed that the HIPed 316LN material is equivalent to a very good fine-grain, isotropic and uniformly forged 316LN. Moreover, ultrasonic inspection showed that this fine and uniform microstructure produced a remarkably low noise, which allow the use of transverse waves at very high frequencies (4 MHz). Defects undetectable in forged material will be easily detected in HIPed material.

Dellis, Ch.; Le Marois, G.; Gentzbittel, J. M.; Robert, G.; Moret, F.

1996-10-01

53

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.A., and Beckermann, C., "Effect of Porosity on Mechanical Properties of 8630 Cast Steel," in Proceedings of the 58th of steel castings. Likewise there are no guidelines relating non-destructive testing or non- destructive

Beckermann, Christoph

54

Duplex stainless steel—Microstructure and properties  

NASA Astrophysics Data System (ADS)

Literature describing the microstructure of austenitic-ferritic stainless steels is reviewed, including phases which can be deleterious, such as ? and ?. The mechanical properties and corrosion resistance of Carpenter Technology's 7-Mo PLUSsr stainless (UNS S32950) demonstrate the resistance of this material to the formation of these phases and their deleterious effects. This material was evaluated in the annealed and welded conditions and after extended thermal treatments to simulate boiler and pressure vessel service.

Debold, Terry A.

1989-03-01

55

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

56

Sensitivity of Steel Casting Simulation Results to Alloy Property Datasets  

E-print Network

1 Sensitivity of Steel Casting Simulation Results to Alloy Property Datasets Kent D. Carlson procedure are compared, and it is seen that the Niyama results for all benchmark alloys can be categorized into three groups, with each group being reasonably represented by a single alloy from that group: all nine

Beckermann, Christoph

57

Influence of niobium microalloying on rotating bending fatigue properties of case carburized steels  

Microsoft Academic Search

Fatigue properties of three case hardening steels have been investigated by means of rotating bending fatigue tests on smooth bar specimens after carburization. Results show that the 0.04% Nb steel had the highest fatigue limit of 1170MPa, while those of the Nb-free and 0.08% Nb steels were 995MPa and 1125MPa, respectively. It is also shown that the 0.04% Nb steel

L. Ma; M. Q. Wang; J. Shi; W. J. Hui; H. Dong

2008-01-01

58

Aging degradation of cast stainless steels: Effects on mechanical properties  

SciTech Connect

A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water operating conditions. Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320, and 290/sup 0/C. The results indicate that thermal aging increases the tensile strength and decreases the impact energy, J/sub IC/, and tearing modulus of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The fracture toughness results are consistent with the Charpy-impact data, i.e., the relative reduction in J/sub IC/ is similar to the relative decrease in impact energy. The ferrite content and concentration of C in the steel have a strong effect on the overall process of low-temperature embrittlement. The low-carbon CF-3 steels are the most resistant and Mo-containing CF-8M steels are most susceptible to embrittlement. Weakening of the ferrite/austenite phase boundaries by carbide precipitates has a significant effect on the kinetics and extent of embrittlement of the high-carbon CF-8 and CF-8M steels, particularly after aging at temperatures greater than or equal to400/sup 0/C. The influence of N content and distribution of ferrite on loss of toughness are discussed. The data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280 to 450/sup 0/C, i.e., extrapolation of high-temperature data to reactor temperatures may not be valid for some compositions of cast stainless steel.

Chopra, O.K.; Chung, H.M.

1987-06-01

59

Wear of steel by rubber  

NASA Technical Reports Server (NTRS)

Wear of a steel blade used as a scraper to abrade rubber surfaces has been found to take place much more rapidly on a cis-polyisoprene (natural rubber) surface than on a cis-polybutadiene surface, and much more rapidly in an inert atmosphere than in air. These observations are attributed to the direct attack upon steel of free-radical species generated by mechanical rupture of elastomer molecules during abrasion.

Gent, A. N.; Pulford, C. T. R.

1978-01-01

60

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

61

Properties of super stainless steels for orthodontic applications.  

PubMed

Orthodontic stainless-steel appliances are considered to be corrosion resistant, but localized corrosion can occur in the oral cavity. This study was undertaken to evaluate the properties of super stainless steels in orthodontic applications. Accordingly, the metallurgical properties, mechanical properties, corrosion resistance, amount of the released nickel, cytotoxicity, and characteristics of the passive film were investigated. Corrosion resistances of the specimens were high and in the following order: super austenitic stainless steel (SR-50A) > super ferritic stainless steel (SFSS) = super duplex stainless steel (SR-6DX) > 316L SS > super martensitic stainless steel (SR-3Mo) in artificial saliva, 37 degrees C. At 500 mV (SCE), current densities of SR-50A, SFSS, SR-6DX, 316L SS, and SR-3Mo were 5.96 microA/cm(2), 20.3 microA/cm(2), 31.9 microA/cm(2), 805 microA/cm(2), and 5.36 mA/cm(2), respectively. Open circuit potentials of SR-50A, 316L SS, SR-6DX, SR-3Mo, and SFSS were - 0.2, - 0.22, - 0.24, - 0.43, and - 0.46 V (SCE), respectively. SR-50A, SFSS, and SR-6DX released below 3 ng/ml nickel for 8 weeks, and increased a little with immersion time, and 316L SS released about 3.5 ng/ml nickel, but SR-3Mo released a large amount of nickel, which increased with immersion time. The study demonstrated that SR-50A, SR-6DX, and SFSS have high corrosion resistance and mild or no cytotoxicity, due to the passive film enhanced by synergistic effect of Mo + N or by high addition effect of Cr + W. All super stainless steels showed very low cytotoxicity regardless of their nickel contents, although SR-3Mo was found to be relatively cytotoxic. From these studies, these steels are considered suitable for orthodontic applications. PMID:15116408

Oh, Keun-Taek; Kim, Young-Sik; Park, Yong-Soo; Kim, Kyoung-Nam

2004-05-15

62

Effect of Welding Processes on Tensile and Impact Properties, Hardness and Microstructure of AISI 409M Ferritic Stainless Joints Fabricated by Duplex Stainless Steel Filler Metal  

Microsoft Academic Search

The effect of welding processes such as shielded metal arc welding, gas metal arc welding and gas tungsten arc welding on tensile and impact properties of the ferritic stainless steel conforming to AISI 409M grade is studied. Rolled plates of 4 mm thickness were used as the base material for preparing single pass butt welded joints. Tensile and impact properties,

AK Lakshminarayanan; K Shanmugam; V Balasubramanian

2009-01-01

63

Touchening High Strength Steel by Warm Working.  

National Technical Information Service (NTIS)

The manganese-molybdenum alloy armor plate steel has a high combination of hardness and toughness. The steel is useful in making aircraft landing gears and ordnance parts such as armor plate steels. The steel contains, by weight, of carbon 0.30 percent ma...

E. J. Ripling, R. S. Lindberg

1966-01-01

64

Tensile property of low carbon steel with gridding units  

NASA Astrophysics Data System (ADS)

Although much effort has been devoted to the mechanical properties of biomimetic coupled laser remelting (BCLR) processed steels, our understanding to the strengthening and toughening mechanisms of it has still remained unclear. To address it, here we studied the roles played by the gridding units of BCLR steels. Tensile tests show that the gridding units have a significant influence on the tensile properties. Interestingly, such an influence is essentially decided by the unit distance of gridding units. The strength increases with the unit distance narrowing while the ductility first increases with it up to a maximum then decreases. The mechanism behind these changes is attributed to the combined effects of the microstructure changes in the units and the stress transition throughout the BCLR samples.

Wang, Chuanwei; Zhou, Hong; Zhang, Zhihui; Jing, Zhengjun; Cong, Dalong; Meng, Chao; Ren, Luquan

2013-05-01

65

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

66

Effect of matrix composition on steel fiber reinforced concrete properties  

SciTech Connect

Since the early 1960's, researchers have conducted experiments to improve the strength and deformation capacity of the concrete matrix by reinforcing it with various types of short cut steel fibers. While such investigations contributed to the understanding of the influence of fibers in improving wide spectrum of concrete mechanical properties, there is insufficient information about the effect of concrete matrix composition in determining the workability and improving the mechanical properties of steel fiber reinforced concrete (SFRC). The primary objectives of this study were to determine the influence of concrete mix composition on SFRC properties in both fresh and hardened state. Also, the percentage air voids and how it influences the strength of SFRC was determined. In addition, rational SFRC design procedure was established. Plain concrete mixes and SFRC mixes containing two types of steel fibers were made. Workability measurement were carried out using the VeBe Consistometer. Entrapped air was measured using the air pressure meter. Flexural strength and flexural toughness measurements were obtained using the third-point loading test. Compressive strength was determined for concrete prisms.

Al-Ghamdy, D.O.

1984-01-01

67

Effect of Cryogenic Treatment on Properties of Cr8Type Cold Work Die Steel  

Microsoft Academic Search

The effect of cryogenic treatment on the properties of Cr8-type cold work die steel was investigated. The results show that cryogenic treatment increases hardness by decreasing retained austenite, but the degree depends on the austenitizing temperature. When quenching at lower austenitizing temperature, the steel can obtain higher toughness by cryogenic treatment substituting conventional treatment process. Cryogenic time has little effect

Hong-xiao CHI; Dang-shen MA; Qi-long YONG; Li-zhi WU; Zhan-pu ZHANG; Yong-wei WANG

2010-01-01

68

MECHANICAL PROPERTIES OF IRRADIATED STAINLESS STEELS. A Compilation of Data in the Literature  

Microsoft Academic Search

Changes in the mechanical properties of stainless steels that are caused ; by fast neutron irradiation are presented aphic form. These data were ; abstracted from classified and unclassified reports published since 1948 by ; USAEC, AECL, and AERE. Data are included for the following stainless steels: AM-; 350, Boron stainless, 301, 302, 43l, 440C, 442, 446, Armco 17-4PH (AMS5643),

1961-01-01

69

Steel Microstructure Effect on Mechanical Properties and Corrosion Behavior of High Strength Low Carbon Steel  

NASA Astrophysics Data System (ADS)

Different thermomechanical treatments were applied to a high strength low carbon steel with a novel chemical composition. As a result, three different microstructures were produced with dissimilar mechanical and corrosion properties. Subsequently, a tempering heat treatment was applied to redistribute the phases in the steel. Microstructure A with 56 pct martensite and 32 pct bainite presented high strength but medium ductility; microstructure C with 95 pct ferrite and 3 pct martensite/austenite resulted in low strength and high ductility, and finally microstructure B with 98 pct bainite and 2 pct martensite/austenite resulted in high strength and ductility. Alternatively the corrosion behavior obtained by polarization curves was characterized in 0.1 M H2SO4, 3 M H2SO4, 3.5 wt pct NaCl, and NS4 solutions resulting in similar magnitudes, while the corrosion behavior acquired by electrochemical impedance spectroscopy had slightly differences in 3 M H2SO4.

Barraza-Fierro, Jesus Israel; Campillo-Illanes, Bernardo; Li, Ximing; Castaneda, Homero

2014-08-01

70

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

71

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

72

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

73

Ultrasonic techniques for determining the mechanical properties of steels  

NASA Astrophysics Data System (ADS)

Previous studies relating changes in ultrasonic velocity and attenuation in solids to stress, grain size, chemistry and other factors, are reviewed. The physics of these relationships is of interest, in view of continuing steel industry needs to measure and produce products having well-defined mechanical properties such as yield strength and tensile strength. For example, higher order elastic constants or scattering coefficients measured using ultrasonic techniques may be predictors of these mechanical properties. Work being conducted at Bethlehem Steel is described in which ultrasonic velocity and attenuation in steel samples is measured during tensile testing, and the ultrasonic measurements are correlated with properties such as yield strength.

Droney, B. E.; Klinman, R.

1982-05-01

74

The mechanical properties of stainless maraging steels  

Microsoft Academic Search

1.Maraging Cr-Ni-Mo-Ti steels with around 1% Ti have good ductility and are not susceptible to cracks at high strength levels. These steels are not susceptible to slow fracture in water on prolonged application of static loads close to the ultimate strength and have a high resistance to low-cycle fatigue. In the quenched condition, with the strength ~100 kg\\/mm2, the steels

E. S. Kagan; Ya. M. Potak; V. V. Sachkov

1969-01-01

75

A novel approach to characterising the mechanical properties of supermartensitic 13 Cr stainless steel welds  

Microsoft Academic Search

Novel measurements of the tensile properties of the weld metal, heat-affected zone (HAZ) and parent plate of supermartensitic 13 Cr stainless steel welds have been made by taking sections from each region and testing with a miniaturised tensile testing machine. Measurements were made on welds produced with a super-duplex stainless steel and a matching filler. The tensile tests were conducted

A. Griffiths; W. Nimmo; B. Roebuck; G. Hinds; A. Turnbull

2004-01-01

76

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

Microsoft Academic Search

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

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

1984-01-01

77

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

Microsoft Academic Search

The effect of deep cryogenic treatment (?196°C) 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

78

The effect of nitrogen on the cold forging properties of 1020 steel  

Microsoft Academic Search

We have studied the effect of nitrogen on the cold forging properties of a low carbon steel as a function of temperature. Five AISI 1020 steels with nitrogen contents from 12 to 180ppm were examined by tensile testing from 25 to 371°C. Yield strength, tensile elongation (ductility), ultimate tensile strength (UTS), strain hardening exponents and strength coefficients were determined. The

T. J. Douthit; C. J. Van Tyne

2005-01-01

79

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 600°C. 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 700-600°C. Moreover, the straightening temperature of the test steel should be higher than 925°C for avoiding the initiation and propagation of surface cracks in billets.

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

2013-09-01

80

Mechanical properties of high manganese steels at cryogenic tempeatures  

SciTech Connect

The purpose of this study is to evaluate the cryogenic properties of two kinds of high Mn steels in an attempt to develop a new cryogenic steel with a higher yield strength than 304LN or 316LN. Sample preparation as well as experimental procedure is described. Mechanical temperature-dependent test results are extensively plotted. Among these results are that high Mn steels are strengthened with N additions of more than 0.2% to meet a yield strength of more than 1 GPa at 4 K; that the fracture thoughness of high C and Mn steel increses with increases in the Mn, Ni, and Cu contents; that addition of Cr enhances the yield strength but deteriorates the fracture toughness; and that nitgroen-strengthened high Mn steels and High C and Mn steels high yield strength, excellent ductility and toughness at 4 K, and show sound EB and MIG welded joints. Results for various specific composite proportions are given.

Hotiuchi, T.; Kasamatsu, Y.; Ogawa, R.; Shimada, M.; Tone, S.; Yamaga, M.

1982-01-01

81

Mechanical and Thermal Properties of Ultra-High Carbon Steel Containing Aluminum.  

National Technical Information Service (NTIS)

The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is sho...

C. K. Syn, D. R. Lesuer, A. Goldberg, H. C. Tsai, O. D. Sherby

2005-01-01

82

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

83

Effect of processing parameters on the microstructure and mechanical properties of TiN film on stainless steel by HCD ion plating  

Microsoft Academic Search

The effect of operation parameters, bias and nitrogen partial pressure in the microstructure and properties of titanium nitride (TiN) films was investigated. The films were grown using hollow cathode discharge ion plating (HCD-IP) on stainless steel. The structure was studied using X-ray diffraction (XRD) and transmission electron microscopy (TEM). Cross-sectional TEM (XTEM) was used to study the effect of bias,

J.-H. Huang; Y.-P. Tsai; G.-P. Yu

1999-01-01

84

Effect of Deep-Cryogenic Treatment on High Speed Steel Properties  

Microsoft Academic Search

Advantages of deep-cryogenic treatment over standard heat treatment of high speed steels for the purpose of obtaining better properties are quoted in an increasing number of scientific articles. This article deals with the most important improvements of high speed steel properties achieved by using deep-cryogenic treatment. The effect of deep-cryogenic treatment on impact and fracture toughness, on erosion wear resistance,

Franjo Cajner; Vojteh Leskovšek; Darko Landek; Hrvoje Cajner

2009-01-01

85

Fatigue properties of a 316L stainless steel coated with different ZrN deposits  

Microsoft Academic Search

The fatigue properties of a 316L stainless steel coated with three different under stoichiometric ZrNx films, deposited by PVD magnetron sputtering are investigated and compared with those of the uncoated substrate. Such a steel can be safely coated with these ZrNx films in order to improve some of its surface properties, without compromising its fatigue behavior. On the contrary, the

J. A. Berr??os-Ort??z; J. G. La Barbera-Sosa; D. G. Teer; E. S. Puchi-Cabrera

2004-01-01

86

Cryogenic mechanical properties of heavy-section weldment in high-manganese austenitic steel  

Microsoft Academic Search

Cryogenic mechanical properties of a heavy-section weldment of high-manganese austenitic steel for the structure of superconducting magnet were evaluated, The heavy-section weld joint with a 200 mm thickness was manufactured by gas tungsten arc welding (GTAW) process using 21Mn-13Cr-5Ni-0.2N-B steel weld material. No cracks were observed in the weld metal. Tensile property and fracture toughness were tested at 4 K.

O. Matsumoto; T. Tsuchiyama; S. Hada

1997-01-01

87

Effect of isothermal heat treatment on microstructure and mechanical properties of Reduced Activation Ferritic Martensitic steel  

NASA Astrophysics Data System (ADS)

Hardness, tensile properties and microstructural changes in 9Cr-1W-0.06Ta-0.22V-0.08C Reduced Activation Ferritic-Martensitic steel have been investigated after subjecting the steel with isothermal heat treatments for 5 min at temperatures in the range 973-1473 K (below Ac1 to above Ac3 transformation temperatures) followed by oil quenching and tempering at 1033 K for 1 h. These studies have been carried out in an effort to assess the strength of the steel at different microstructural conditions. Optical, scanning and transmission electron microscopic investigations have been carried out to assess the microstructural changes of the steel upon various heat treatments. The steel developed predominantly tempered martensitic structure after the heat treatments. The hardness, tensile strength and the prior austenitic grain size of the steel exhibited minimum values for soaking heat treatment in the intercritical temperature range (i.e.) between Ac1 and Ac3; whereas the ductility was maximum. With increase in isothermal heat treatment temperature above Ac3, hardness, tensile strength and grain size of the steel were found to increase with consequent decrease in tensile ductility. TEM investigations revealed that the coarsening of subgrain and precipitates at grain and sub-grain boundaries on heat treatment of the steel in the inter-critical temperature range. The tensile properties of the steel have been correlated with microstructure.

Chandravathi, K. S.; Sasmal, C. S.; Laha, K.; Parameswaran, P.; Nandagopal, M.; Vijayanand, V. D.; Mathew, M. D.; Jayakumar, T.; Rajendra Kumar, E.

2013-04-01

88

The effect of molybdenum on high-temperature properties of 9 pct Cr steels  

NASA Astrophysics Data System (ADS)

Heat-resistant 9 Cr steels with 1, 2, and 3 pct Mo were tested for mechanical properties, weldability, and creep-rupture properties. The elevated-temperature and rupture strengths increase with increasing molybdenum content. While the 9 Cr-1 Mo steel is martensitic and is precipitation strengthened with carbides, the 9 Cr-2 Mo and 9 Cr-3 Mo steels receive added benefits from precipitation of Laves phase and solid-solution strengthening. The latter cause little decrease in ductility and impact resistance. The 9 Cr-2 Mo and 9 Cr-3 Mo steels are characterized by a duplex microstructure which aids weldability. Weld cracking tests show no need for preheating the latter steels, although the martensitic 9 Cr-1 Mo steel is known to be susceptible to weld cracking if not preheated. Both duplex-structure steels have good resistance to stress-relief cracking. Anisotropy of mechanical properties, due to the orientation of the duplex structure in the rolling direction, is less than that observed in the fully martensitic 9 Cr-1 Mo steel.

Grobner, P. J.; Hagel, W. C.

1980-04-01

89

Hydrogen Effect on Nanomechanical Properties of the Nitrided Steel  

NASA Astrophysics Data System (ADS)

In situ electrochemical nanoindentation is used to examine the effect of electrochemically charged hydrogen on mechanical properties of the nitride layer on low-alloy 2.25Cr-1Mo martensitic structural steel. By application of this method, we were able to trace the changes in the mechanical properties due to the absorption of atomic hydrogen to different depths within the compound and diffusion layers. The results clearly show that the hydrogen charging of the nitriding layer can soften the layer and reduce the hardness within both the compound and the diffusion layers. The effect is completely reversible and by removal of the hydrogen, the hardness recovers to its original value. The reduction in hardness of the nitride layer does not correlate to the nitrogen concentration, but it seems to be influenced by the microstructure and residual stress within the compound and diffusion layers. Findings show that nitriding can be a promising way to control the hydrogen embrittlement of the tempered martensitic steels.

Barnoush, Afrooz; Asgari, Masoud; Johnsen, Roy; Hoel, Rune

2013-02-01

90

Mechanical properties of structural amorphous steels: Intrinsic correlations, conflicts, and optimizing strategies  

NASA Astrophysics Data System (ADS)

Amorphous steels have demonstrated superior properties and great potentials for structural applications since their emergence, yet it still remains unclear about how and why their mechanical properties are correlated with other factors and how to achieve intended properties by designing their compositions. Here, the intrinsic interdependences among the mechanical, thermal, and elastic properties of various amorphous steels are systematically elucidated and a general trade-off relation is exposed between the strength and ductility/toughness. Encouragingly, a breakthrough is achievable that the strength and ductility/toughness can be simultaneously improved by tuning the compositions. The composition dependences of the properties and alloying effects are further analyzed thoroughly and interpreted from the fundamental plastic flow and atomic bonding characters. Most importantly, systematic strategies are outlined for optimizing the mechanical properties of the amorphous steels. The study may help establish the intrinsic correlations among the compositions, atomic structures, and properties of the amorphous steels, and provide useful guidance for their alloy design and property optimization. Thus, it is believed to have implications for the development and applications of the structural amorphous steels.

Liu, Z. Q.; Zhang, Z. F.

2013-12-01

91

Mechanical properties of structural amorphous steels: Intrinsic correlations, conflicts, and optimizing strategies  

SciTech Connect

Amorphous steels have demonstrated superior properties and great potentials for structural applications since their emergence, yet it still remains unclear about how and why their mechanical properties are correlated with other factors and how to achieve intended properties by designing their compositions. Here, the intrinsic interdependences among the mechanical, thermal, and elastic properties of various amorphous steels are systematically elucidated and a general trade-off relation is exposed between the strength and ductility/toughness. Encouragingly, a breakthrough is achievable that the strength and ductility/toughness can be simultaneously improved by tuning the compositions. The composition dependences of the properties and alloying effects are further analyzed thoroughly and interpreted from the fundamental plastic flow and atomic bonding characters. Most importantly, systematic strategies are outlined for optimizing the mechanical properties of the amorphous steels. The study may help establish the intrinsic correlations among the compositions, atomic structures, and properties of the amorphous steels, and provide useful guidance for their alloy design and property optimization. Thus, it is believed to have implications for the development and applications of the structural amorphous steels.

Liu, Z. Q., E-mail: liuzq@imr.ac.cn; Zhang, Z. F., E-mail: zhfzhang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

2013-12-28

92

Enhanced Mechanical Properties through Reversion in Metastable Austenitic Stainless Steels  

Microsoft Academic Search

A novel processing route of cold rolling and reversion annealing for enhanced mechanical properties has been investigated\\u000a in metastable 17Cr-7Ni-type austenitic stainless steels, i.e., commercial grades AISI 301LN and AISI 301, and in some experimental heats. The investigation was essentially aimed at studying the possibility of processing nano\\/submicron-grained structure in these\\u000a steels and to rationalize the possible effects of alloying

M. C. Somani; P. Juntunen; L. P. Karjalainen; R. D. K. Misra; A. Kyröläinen

2009-01-01

93

Properties of steel fiber reinforced fly ash concrete  

Microsoft Academic Search

This paper reports on a comprehensive study on the properties of concrete containing fly ash and steel fibers. Properties studied include unit weight and workability of fresh concrete, and compressive strength, flexural tensile strength, splitting tensile strength, elasticity modulus, sorptivity coefficient, drying shrinkage and freeze–thaw resistance of hardened concrete. Fly ash content used was 0%, 15% and 30% in mass

Cengiz Duran Ati?; Okan Karahan

2009-01-01

94

Stress relaxation properties of prestressed steel wires  

Microsoft Academic Search

In this study, stress relaxation phenomenon has been examined generally. Experiments were carried out on carbon steel wires with diameter 8mm which are particularly used in prestressed concrete composites. Thermomechanically heat treatment was also carried out on this wire in order to relieve the residual stresses accumulated after the cold work. The heat treatment temperature and the stretch ratio, which

Adalet Zeren; Muzaffer Zeren

2003-01-01

95

Influence of thermal aging on microstructure and mechanical properties of CLAM steel  

NASA Astrophysics Data System (ADS)

In order to investigate the influence of thermal aging on microstructure and mechanical properties of CLAM (China low activation martensitic) steel, a comparison study was made on the as-tempered and the aged steels. The tempered CLAM steels were subjected to aging treatment at 600 °C for 1100 h and 3000 h, and at 650 °C for 1100 h, respectively. The changes of microstructure were characterized by both transmission electron microscope (TEM) and scanning electron microscope (SEM). The mechanical properties were evaluated by Charpy impact, tensile and Vickers hardness tests. The upper shelf energy (USE) of the thermal aged CLAM steel decreased with the extension of aging time, while the yield strength changed slightly. After long-term thermal aging, the MX type precipitates remained stable. The coarsening of M23C6 and the formation of Laves phase were confirmed by scanning/transmission electron microscopes. The Laves phase was the main factor leading to the increase of DBTT.

Huang, Lixin; Hu, Xue; Yang, Chunguang; Yan, Wei; Xiao, Furen; Shan, Yiyin; Yang, Ke

2013-11-01

96

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

97

Steel casting by diffusion solidification  

Microsoft Academic Search

A new process for casting and welding carbon steels is described in which carbon diffuses isothermally or adiabatically within\\u000a an intimate mixture of solid low carbon steel and high carbon liquid iron to effect solidification and subsequent homogenization\\u000a with respect to carbon. Advantages over conventional casting processes and products result from 1) 150 to 200°C lower casting\\u000a temperature; 2) reduced

George Langford; Robert E. Cunningham

1978-01-01

98

TiC-maraging stainless steel composite: microstructure, mechanical and wear properties  

Microsoft Academic Search

Particulate TiC reinforced 17-4PH and 465 maraging stainless steel matrix composites were processed by conventional powder metallurgy (P\\/M). TiC-maraging stainless steel composites with theoretical density >97% were produced using conventional P\\/M. The microstructure, and mechanical and wear properties of the composites were evaluated. The microstructure of the composites consisted of (core-rim structure) spherical and semi-spherical TiC particles depending on the

Farid Akhtar; Shiju GUO; Peizhong FENG; Shah Khadijah Ali; Askari Syed Javid

2006-01-01

99

Structure and properties of X150CrMo12 steel after PVDM-R by magnetron deposition of chromium nitride coatings with next heat treatment  

Microsoft Academic Search

The CrN coatings have been deposited on X150CrMo12 steel substrates by sputtering of a sintered chromium target at metallizing temperatures Ts, ranging between 450 and 850°C and bias voltage Us, ranging from 0 to ?200V by the method of “Plasma Vacuum Diffusive Metallizing-Reactive scheme” (PVDM-R) in a single-chamber vacuum furnace with a graphite heater and a heat-isolative chamber, made of

R. Shishkov; M. Jordanov; W. Kwa?ny

2004-01-01

100

Microstructure and property modifications of an AISI H13 (4Cr5MoSiV) steel induced by pulsed electron beam treatment  

SciTech Connect

In the present work, surface modifications generated by the low energy high current pulsed electron beam (LEHCPEB) treatments have been investigated on an AISI H13 (4Cr5MoSiV) steel. From the observations of scanning electron microscopy, x-ray diffraction, and electron back scattering diffraction determinations, it could be established that the final structure in the melted layer is a mixture of ultrafine {delta} phase, martensite, and residual austenite. The formation of the heterogeneous microstructures on the surface layer is related to the very rapid heating, melting, solidification, and cooling induced by the LEHCPEB irradiation. After the LEHCPEB treatment, the wear resistance of the steel effectively improved. This can be mainly attributed to the higher hardness of the ultrafine structures formed on the top surface and the hardened subsurface layers after the treatment.

Zhang Kemin; Zou Jianxin; Grosdidier, Thierry; Dong Chuang [School of Materials Engineering, Shanghai University of Engineering Science, Shanghai 201620 (China); Shanghai Engineering Research Center of Mg Materials and Applications and School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China) and Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France); Laboratoire d'Etude des Textures et Applications aux Materiaux (LETAM, CNRS 3143), Universite Paul Verlaine Metz, Ile du Saulcy, 57045 Metz (France) and Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China); Laboratory of Materials Modification by Laser, Electron and Ion Beams, Dalian University of Technology, Dalian 116024 (China)

2010-11-15

101

Microstructures and Properties of Friction Freeform Fabricated Borated Stainless Steel  

NASA Astrophysics Data System (ADS)

A new additive manufacturing process, termed "friction freeform fabrication," has been recently proposed by the authors. One of the unique capabilities of the process is that it can facilitate fabrication of three-dimensional parts in materials that are difficult to fusion deposit. The current study is a striking demonstration of this, in which cylindrical samples of 40 mm height and 10 mm diameter were successfully produced in borated stainless steel ASTM 304B4, a material known to be very difficult to fusion weld or deposit. Microstructures and mechanical properties of these samples were investigated in detail and were compared to those of standard wrought-processed alloy 304B4 Grade B material.

Dilip, J. J. S.; Janaki Ram, G. D.

2013-10-01

102

Magnetic properties of an AISI 420 martensitic stainless steel  

Microsoft Academic Search

The magnetic properties (coercive force, saturation and residual magnetization, and Curie temperature) of an AISI 420 steel were measured for different heat treatment conditions (quenching and tempering). The results show that the material is magnetically softer in the annealed condition and after oil quenching an increase of coercive force (MHc) and residual induction (Br) and a decrease of saturation magnetization

S. S. M. Tavares; D. Fruchart; S. Miraglia; D. Laborie

2000-01-01

103

Ultrasonic techniques for determining the mechanical properties of steels  

Microsoft Academic Search

Previous studies relating changes in ultrasonic velocity and attenuation in solids to stress, grain size, chemistry and other factors, are reviewed. The physics of these relationships is of interest, in view of continuing steel industry needs to measure and produce products having well-defined mechanical properties such as yield strength and tensile strength. For example, higher order elastic constants or scattering

B. E. Droney; R. Klinman

1982-01-01

104

X-Ray Study of Mechanical Properties of TiN Thin Films Coated on Steel by Ion Beam Mixing Method  

Microsoft Academic Search

The thin films of titanium nitride(TiN)with the thickness of 0.5, 1.0, 2.0, 4.0µm were coated on a steel substrate by the ion beam mixing method. The film had a strong fiber texture with axis perpendicular to the film surface. The initial residual stress was equi-biaxial compression between -4.4 to -5.6GPa. For all thickness cases, the initial part of the changes

Toshimasa Ito; Keisuke Tanaka; Yoshiaki Akiniwa; Takahiro Ishii; Yasuhiro Miki

2003-01-01

105

EFFECT OF VANADIUM ON STRUCTURE-PROPERTY RELATIONS OF DUAL PHASE Fe/Mn/Si/0.1C STEELS  

SciTech Connect

The role of vanadium on the structure-property relations of dual phase Fe/Mn/Si/0.1C steels has been investigated. After intercritical annealing at 800°C, the steels with and without V were either iced brine quenched or air cooled. The steels were also solution treated at 900°C and subsequently air cooled. Although V modified the resultant microstructure, especially the morphology of carbides, the corresponding mechanical properties are not significantly affected by the modified microstructures. It is concluded that V is not beneficial to such dual phase low carbon steels.

Nakagawa, Alvin; Koo, J.Y.; Thomas, G.

1981-03-01

106

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

107

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

108

Mechanical Properties of Structural Steels in Hydrogen  

E-print Network

· Soak (30 min.) at pressure · Test to failure #12;Tensile Properties · Mechanical Properties Average Properties 0.2%Yield (MPa) Dev. UTS (MPa) Dev. Elong. at failure Dev. Reduction of Area (%) Dev. Air 355.3 15 and demonstrate K dominance for long cracks in WOL specimen a/ W = 0.941 KI VmE/ W1/ 2 0.18 0.16 0.14 0.12 0

109

Optimization of properties of carburized high-chromium steels  

Microsoft Academic Search

The influence of the pack carburization regime on the bulk strength and wear properties of hypoeutectoid (0.3 wt% C, 3–17wt% Cr) and hypereutectoid (0.8 wt% C, 4–16 wt% Cr) high-chromium steels was examined (950–1050 °C, and duration, 4–8h). The results obtained enable an optimum combination of bulk (tensile, bending and impact strength) and surface properties (abrasive and unlubricated sliding wear

B. M. Khusid; E. M. Khusid; B. B. Khina

1995-01-01

110

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

111

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

112

Influence of martensite content and morphology on tensile and impact properties of high-martensite dual-phase steels  

Microsoft Academic Search

A series of dual-phase (DP) steels containing finely dispersed martensite with different volume fractions of martensite (V\\u000a m) were produced by intermediate quenching of a boron- and vanadium-containing microalloyed steel. The volume fraction of martensite\\u000a was varied from 0.3 to 0.8 by changing the intercritical annealing temperature. The tensile and impact properties of these\\u000a steels were studied and compared to

A. Bag; K. K. Ray; E. S. Dwarakadasa

1999-01-01

113

Effect of Alloying Elements on Tensile Properties, Microstructure, and Corrosion Resistance of Reinforcing Bar Steel  

NASA Astrophysics Data System (ADS)

The effect of copper, phosphorus, and chromium present in a semikilled reinforcing bar steel produced by in-line quenching [thermomechanical treatment (TMT)] process on the tensile properties, microstructure, and corrosion resistance of steel in simulated chloride environment has been investigated. The results have been compared with that of a semikilled C-Mn reinforcing bar steel without these alloying elements produced by the same process route. Though the amount of phosphorus (0.11 wt.%) was higher than that specified by ASTM A 706 standard, the Cu-P-Cr steel exhibited a composite microstructure, and good balance of yield stress, tensile stress, elongation, and ultimate tensile to yield stress ratio. Two conventional test methods, namely, the salt fog, and potentiodynamic polarization tests, were used for the corrosion test. The rust formed on Cu-P-Cr steel was adherent, and was of multiple colors, while the corrosion products formed on the C-Mn steel were weakly adherent and relatively darker blue. Also, the free corrosion potential of the Cu-P-Cr steel was nobler, and the corrosion current was markedly lower than that of a C-Mn rebar. The Cu-P-Cr steel did not develop any pits/deep grooves on its surface even after the prolonged exposure to salt fog. The improved corrosion resistance of the Cu-P-Cr steel has been attributed to the presence of copper, phosphorus, and small amount of chromium in the dense, adherent rust layer on the surface of reinforcing steel bar. A schematic mechanism of charge transfer has been proposed to explain the improved corrosion resistance of the Cu-P-Cr alloyed TMT rebar.

Panigrahi, B. K.; Srikanth, S.; Sahoo, G.

2009-11-01

114

Effects of Aging Structures and Humidity on Fatigue Properties of Maraging Steel  

NASA Astrophysics Data System (ADS)

Effects of aging structures and humidity on fatigue properties of 350 grade 18% Ni maraging steel were investigated under rotating bending in relative humidity of 25% and 85%. Aging conditions tested were a conventional single aging and a double one which was aged at low temperature after the conventional aging. In each aging, under and peak aged steels were prepared. Tensile strength was increased by the double aging without reduction of the ductility. Proportional relation between fatigue limit and Vickers hardness held until 750HV in low humidity. However fatigue strength was largely decreased by high humidity, especially in the peak aged steel at the single aging. The decrease in fatigue strength by high humidity was mainly caused by the acceleration of a crack initiation due to the anodic dissolution. The acceleration of a crack initiation was larger in the steel peak aged at the single aging with larger precipitated particles.

Hayashi, Kousuke; Nagano, Takanori; Moriyama, Michihiko; Wang, Xishu; Kawagoishi, Norio

115

Thermophysical property measurements on low alloy high strength carbon steels  

SciTech Connect

The alloys of interest in this study were AISI Type 4230 and Type 4320 low alloy high strength carbon steels. They are heat-treatable steels and are usually used in the quenched and tempered condition. The Type 4130 has about 0.3% (wt.)C, 0.95%Cr, and 0.2% Mo. The Type 4320 has about 0.2%C, 1.7%Ni, 0.7%Cr, and 0.3% Mo. They are among the most popular alloy steels because of their excellent combination of mechanical properties and are used in both cast and wrought forms for many applications requiring high strength and toughness. However, during the casting operation, carbon segregation to the part surface forms a high carbon content surface layer in the part, which will induce surface cracking in the subsequent quenching process. And, during the welding operation, the critical cooling rate in the heat-affected zone (HAZ) will determine if the weldment is crack-free or not. Thus, the numerical effort to study the thermal history, microstructure evolution and residual stress development during welding and casting is critical to the application of these steels. This modeling effect requires the accurate knowledge of thermophysical properties, such as thermal expansion, solidus and liquidus temperatures, specific heat capacity, and heat of fusion. Unfortunately, these thermophysical properties are unavailable for temperatures over 1,000 C (1,2), thus the need for this study.

Li, M.; Brooks, J.A. [Sandia National Labs., Livermore, CA (United States)] [Sandia National Labs., Livermore, CA (United States); Atteridge, D.G. [Oregon Graduate Inst., Portland, OR (United States). Dept. of Materials Science and Engineering] [Oregon Graduate Inst., Portland, OR (United States). Dept. of Materials Science and Engineering; Porter, W.D. [Oak Ridge National Lab., TN (United States). Physical Properties User Center] [Oak Ridge National Lab., TN (United States). Physical Properties User Center

1997-06-15

116

Relaxation Properties of Prestressing Steels for Concrete Reactor Vessels.  

National Technical Information Service (NTIS)

The effects of temperature, initial tension, and load duration upon relaxation of prestressing steels are discussed, and results of relaxation tests performed by General Atomic Company are presented in the report. The tests were conducted at temperatures ...

V. Nicolayeff

1978-01-01

117

Thermally oxidised rutile-TiO 2 coating on stainless steel for tribological properties and corrosion resistance enhancement  

Microsoft Academic Search

In the present work, a novel process has been developed to improve the tribological and corrosion properties of austenitic stainless steels. Efforts have been made to deposit titanium coatings onto AISI 316L stainless steel by magnetron sputtering, and then to partially convert the titanium coatings to titanium oxide by thermal oxidation. The resultant coating has a layered structure, comprising of

D. Siva Rama Krishna; Y. Sun

2005-01-01

118

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

119

High Strength Stainless Steel Properties that Affect Resistance Welding  

SciTech Connect

This report discusses results of a study on selected high strength stainless steel alloy properties that affect resistance welding. The austenitic alloys A-286, JBK-75 (Modified A-286), 21-6-9, 22-13-5, 316 and 304L were investigated and compared. The former two are age hardenable, and the latter four obtain their strength through work hardening. Properties investigated include corrosion and its relationship to chemical cleaning, the effects of heat treatment on strength and surface condition, and the effect of mechanical properties on strength and weldability.

Kanne, W.R.

2001-08-01

120

Cryogenic mechanical properties of heavy-section weldment in high-manganese austenitic steel  

SciTech Connect

Cryogenic mechanical properties of a heavy-section weldment of high-manganese austenitic steel for the structure of superconducting magnet were evaluated, The heavy-section weld joint with a 200 mm thickness was manufactured by gas tungsten arc welding (GTAW) process using 21Mn-13Cr-5Ni-0.2N-B steel weld material. No cracks were observed in the weld metal. Tensile property and fracture toughness were tested at 4 K. The yield strength and the fracture toughness value, K{sub Ic}(J), were 1223 - 1278 MPa and 181{approximately} 201 MPam{sup {1/2}} in the weld metal, respectively.

Matsumoto, O.; Tsuchiyama, T.; Hada, S. [Kobe Steel Ltd., Takasago (Japan)] [and others

1997-06-01

121

The microstructural stability and mechanical properties of two low activation martensitic steels  

SciTech Connect

A desirable feature of future magnetically confined fusion reactors is the prospect of producing low level radioactive waste. In order to minimize the volume of radioactive material, in particular from the first wall and blanket structures, reduced long term activation alloys are being developed. Here, a low activation composition of a martensitic 9% Cr steel has been studied, based on the DIN (Deutsches Inst. fuer Normung) 1.4914 composition (MANET) but replacing Ni, Mo and Nb by the low activation elements W, V and Ta. Two casts were produced from high purity components, in which the effects of controlled additions of Mn (0.58 and 0.055 wt. %) and N (7 and 290 wt. ppm) were studied, so that the final compositions resulted in one cast with high Mn and low N (steel A) and the other with the opposite conditions (steel B). The two steels were evaluated in terms of structural stability and mechanical properties under tensile, fatigue and fracture toughness tests. It has been found that both alloys have a DBTT below room temperature, which in the case of the steel A is 70 K below that of MANET. Although the tensile strength is somewhat below that of the parent steel, both steels have longer fatigue life.

Victoria, M.; Marmy, P. [Ecole Polytechnique Federale de Lausanne, Villigen PSI (Switzerland); Batawi, E.; Peters, J. [Sulzer Innotec, Winterthur (Switzerland); Briguet, C.; Rezai-Aria, F. [Ecole Polytechnique Federale de Lausanne (Switzerland). Dept. of Materials; Gavillet, D. [Paul Scherrer Inst., Villigen PSI (Switzerland). Lab. for Materials Behavior

1996-12-31

122

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

Microsoft Academic Search

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,

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

1984-01-01

123

Cryogenic properties of new austenitic stainless steel for fusion reactor superconducting magnets  

NASA Astrophysics Data System (ADS)

A non-magnetic austenitic stainless steel has been developed, which has an adequate combination of yield strength and fracture toughness at liquid helium temperature, as a candidate structural material for fusion reactor superconducting magnets. The salient feature of the steel is its low-temperature toughness preserved after aging equivalent to the wind-and-react heat treatment of Nb 3Sn superconducting coil. The steel also keeps its toughness after electron beam welding. Its composition is characterized by addition of vanadium and nitrogen to 25Cr-14Ni-0.5Mo austenitic stainless steel. Microscopic observations have suggested that finely dispersed precipitates, presumably vanadium carbonitrides, are responsible for the excellent cryogenic mechanical properties.

Nohara, Kiyohiko; Shimotomai, Michio; Habu, Yasuhiro

1989-12-01

124

Corrosion inhibition of steel by bacteria  

SciTech Connect

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 bacteria were transferred to a natural seawater flow system, the inhibition effect disappeared during the first 2 weeks.

Hernandez, G.; Kucera, V.; Thierry, D.; Pedersen, A. (Swedish Corrosion Inst., Stockholm (Sweden)); Hermansson, M. (Univ. of Gothenburg (Sweden). Dept. of General and Marine Microbiology)

1994-08-01

125

Retention of implanted hydrogen and helium in martensitic stainless steels and their effects on mechanical properties  

Microsoft Academic Search

Martensitic stainless steels are candidate materials for the target structure of the European Spallation Source (ESS). Hydrogen and helium produced by nuclear transmutation in the proton beam and in the energetic neutron field cause changes of material properties in addition to those caused by atomic displacement. The present work presents results of diffusion and retention of hydrogen and helium, derived

P. Jung; C. Liu; J. Chen

2001-01-01

126

Physicochemical and mineralogical properties of stainless steel slags oriented to metal recovery  

Microsoft Academic Search

In the present paper, physicochemical and mineralogical properties of stainless steel slags oriented to metal recovery were studied by using various methods. The tests were conducted on two types of slag, namely EAF slag (Electric Arc Furnace) and AOD slag (Argon Oxygen Decarburisation). The samples were collected from the tailings of a slag processing plant operated by Bergslagens Stålservice AB

Huiting Shen; E Forssberg; Ulf Nordström

2004-01-01

127

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

E-print Network

Author's personal copy Magnetic properties of stainless steels at room and cryogenic temperatures knowledge no studies of the cryogenic properties of magnetic stainless steels have previously been made, although some measurements have been made with martensite austenite mixtures [8] and austenitic steels [9

Oxley, Paul

128

Investigation of the mechanical properties and microstructure of friction welded joints between AISI 4140 and AISI 1050 steels  

Microsoft Academic Search

Joining of dissimilar metals is one of the most essential needs of industries. Manufacturing with joint of alloy steel and normal carbon steel is used in production, because it decreases raw material cost. In this study, joining of AISI 4140 steel (medium carbon and low alloy steel) and AISI 1050 steel (medium carbon steel) was successfully achieved. Mechanical properties, macro

Sare Celik; Ismail Ersozlu

2009-01-01

129

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 Widmanstätten 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

130

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 Widmanstätten 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

2014-07-01

131

Ultrasonic investigations of cermets elastic properties in dependence on steel concentration and temperature of sintering  

NASA Astrophysics Data System (ADS)

Cermets is a ceramic-metal composite usually produced by sintering a precompacted mixture of the initial powders. These composite materials were created for industrial applications to produce engineering structures possessing a high strength, thermal stability and resistance to aggressive media. In the present work elastic properties of cermets samples, obtained by sintering of corundum (?-Al2O3) and stainless steel powders were investigated in dependence on steel concentration 5 - 35% wt. and on temperature of sintering in vacuum 1400-1700°C. It was stated that values of elastic moduli are in complex dependence on concentration and temperature, reach maxima at steel concentration 15 - 20% wt. and increase with sintering temperature rise. In the work also the results of cermets microstructure researches and discussion of these results are presented. The results are discussed from stand view of ultrasound propagation through medium having grain boundaries which influence on the physical properties of composite.

Abramovich, A.

2012-12-01

132

Magnetic properties of maraging steels in relation to nickel concentration  

SciTech Connect

Magnetic properties of maraging steels have been investigated as a function of nickel concentration. The alloys nickel content varied from 12 to 24 wt pct, while other alloying constituents were kept at a level maintained in the 18Ni-2,400 MPA-grade maraging steel. The magnetic properties were determined following aging for 1 hour in the temperature range of 450 to 750 C. In every alloy investigated, the coercive field increased with aging temperature, reaching a maximum around 670 C {+-} 30 C. The saturation magnetization values were lowest around temperatures where maximum coercive field was observed. The coercive field increased from {approximately}55 to {approximately}175 Oe ({approximately}4,380 to {approximately} 13,900 amp/meter) and the corresponding saturation magnetization decreased from {approximately}18,500 to {approximately}4,000 G ({approximately}1.85 to {approximately}0.4 T) in the alloys containing 12 and 24 wt pct Ni, respectively. The reverted austenite increased from 25 vol pct at 12 wt pct Ni to 10 vol pct at 24 wt pct Ni. The hardness and Charpy impact strength of the alloys have also been determined. An attempt has been made to correlate magnetic properties with different phase transformations occurring in maraging steels.

Ahmed, M.; Nasim, I.; Ayub, H. [Dr. A.Q. Khan Research Labs., Rawalpindi (Pakistan); Hasnain, K. [Quaid-i-Azam Univ., Islamabad (Pakistan)

1995-07-01

133

Effect of hydrogen on the mechanical properties of steels with diffusion coatings  

Microsoft Academic Search

The purpose of this work was to determine the possibility of using diffusion coatings to prevent the harmful effect of hydrogen on the mechanical properties. The experiments were made with samples of steel 20 with coatings obtained by diffusion saturation with chromium, aluminum, and both elements at the same time. The phase composition of the coatings, concentration of the diffusing

Yu. N. Nikiforchin; N. I. Dydyn; A. L. Bichuya; A. S. Osered'ko; V. F. Shatinskii

1977-01-01

134

Mechanical and Thermal Properties of UltraHigh Carbon Steel Containing Aluminum  

Microsoft Academic Search

The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is shown that this change is a function of the atomic percent of solute and of the valence state when comparisons are made with UHCSs

C K Syn; D R Lesuer; A Goldberg; H Tsai; O D Sherby

2006-01-01

135

Mechanical and Thermal Properties of UltraHigh Carbon Steel Containing Aluminum  

Microsoft Academic Search

The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is shown that this change is a function of the atomic percent of solute and of the valence state when comparisons are made with UHCSs

C K Syn; D R Lesuer; A Goldberg; H C Tsai; O D Sherby

2005-01-01

136

Cyclic Material Properties Test to Determine Hardening/Softening Characteristics of HY-80 Steel  

SciTech Connect

The Cyclic Material Properties Test was structured to obtain and provide experimental data for determining cyclic hardening/softening characteristics of HY-80 steel. The inelastic strain history data generated by this test program and the resulting cyclic stress-strain curve will be used to enhance material models in the finite element codes used to perform nonlinear elastic-plastic analysis.

S.C. Hodge; J.M. Minicucci; T.F. Trimble

2003-04-30

137

Effect of alloying elements on the properties of silicon-manganese steel  

Microsoft Academic Search

The change points of the steel were determined in a Chevenar dilatometer with photographic recording. The hardenability was determined by the end-quench method. The samples for testing the mechanical properties were oversize to allow for grinding. The tensile strength tests were made with samples 6 mm in diameter, the impact tests with Mesnager samples. The carbon concentration through the depth

S. S. Iskhakov

1969-01-01

138

Mechanical properties and TEM examination of RAFM steels irradiated up to 70 dpa in BOR-60  

NASA Astrophysics Data System (ADS)

Mechanical properties of Reduced Activation Ferritic/Martensitic (RAFM) steels were studied after irradiation in BOR-60 reactor to a neutron displacement damage of 70 dpa at 330-340 °C. Yield stress and Ductile-to-Brittle-Transition-Temperature of EUROFER97 indicate saturation of hardening and embrittlement. The phenomenological models for description of microstructure evolution and resulting irradiation hardening and embrittlement are discussed. The evolution of yield stress with dose is qualitatively understood within a Whapham and Makin model. Dislocation loops examined in TEM are considered a main source for low-temperature irradiation hardening. The analysis of the fatigue data in terms of the inelastic strain reveals comparable fatigue behaviour both for unirradiated and irradiated conditions, which can be described by a common Manson-Coffin relation. The study of helium effects in B-doped model steels indicated progressive material embrittlement with helium content. Post-irradiation annealing of RAFM steels yielded substantial recovery of mechanical properties.

Gaganidze, E.; Petersen, C.; Materna-Morris, E.; Dethloff, C.; Weiß, O. J.; Aktaa, J.; Povstyanko, A.; Fedoseev, A.; Makarov, O.; Prokhorov, V.

2011-10-01

139

Tensile and creep properties of an oxide dispersion-strengthened ferritic steel  

NASA Astrophysics Data System (ADS)

The tensile and creep properties of two oxide dispersion-strengthened (ODS) steels with nominal compositions of Fe-12Cr-0.25Y 2O 3 (designated 12Y1) and Fe-12Cr-2.5W-0.4Ti-0.25Y 2O 3 (12YWT) were investigated. Optical microscopy, transmission electron microscopy, and atom probe field ion microscopy studies indicated that the 12YWT contained a high density of extremely fine Y-Ti-O clusters, compared to the much larger oxide particles in the 12Y1. The fine dispersion of particles gave the 12YWT better tensile and creep properties compared to commercial ODS alloys and ferritic/martensitic steels that would be replaced by the new ODS steel.

Klueh, R. L.; Maziasz, P. J.; Kim, I. S.; Heatherly, L.; Hoelzer, D. T.; Hashimoto, N.; Kenik, E. A.; Miyahara, K.

2002-12-01

140

Physicomechanical properties of powdered 30N2M steel after carburization  

Microsoft Academic Search

The effect of the carburization time (0.5–2.0 h) on the magnetic and electric properties, the structural state, and the hardness of 30N2M steel was studied. The mechanical and physical properties of carburized steel are compared to those of conventionally sintered steel. The problems of magnetic structural analysis of carburized steel are discussed. It is concluded that in order to determine

A. I. Ul'yanov; R. G. Faizullin; A. I. Zvonarev

1993-01-01

141

Effect of the sulfide phase on the properties of steel after heat treatment  

SciTech Connect

The results of investigations concerned with the effect of the cooling regimes in the austenitic range on the nature of the segregation of sulfides in steels are presented. Experiments were carried out mainly with steel 18Kh2N4MA conventionally melted with low (0.008%) and high (0.04%) sulfur content and after electroslag remelting (ESR) (0.005% S). Results from an investigation of the change of morphology in dependence on the temperature and time of isothermal holding are presented in a diagram illustrating segregation for the predominating kinds of sulfides. The change of morphology and the nature of the distribution of sulfides affected both the fracture and impact toughness of the steel. The effect of the cooling rate from the overheating temperature on the impact toughness of ESR steels and of conventionally melted steels was examined. For ESR steels, characterized by low sulfur content, it was found that the mechanical properties can be changed by controlling the shape and distribution of inclusions of the nonmetallic phase, viz., manganese sulfides, during heat treatment.

Sadovskii, V.D.; Kut'in, A.B.; Gerbikh, N.M.

1988-05-01

142

Effect of silica fume and steel fibers on some properties of high-strength concrete  

Microsoft Academic Search

The main disadvantage of high-strength concrete is its highly brittle behavior and this can beovercome by adding fibers to the concrete. This would also improve some other mechanical properties of high-strength concrete such as tensile strength and compressive strength. These properties are not very well established for high-strength steel-fiber reinforced concrete (HSFRC) yet. In this study the influence of silica

Özgür Eren; Tahir Çelik

1997-01-01

143

Processing of Nano/submicron Grained Stainless Steel 304L by AN Advanced Thermomechanical Process  

NASA Astrophysics Data System (ADS)

Nano/Submicron crystalline grains of about 250 nm were obtained in a metastable austenitic stainless steel AISI304L by an advanced thermomechanical process consisting of heavy conventional cold rolling and annealing. Effects of cold thickness reduction and temperature and time of the reversion treatment on microstructure and mechanical properties of the steel were investigated. The nano-structured austenitic steel exhibited not only high strength (above 1 GPa) but also good elongation (above 50%).

Forouzan, F.; Kermanpur, A.; Najafizadeh, A.; Hedayati, A.

144

Highly Anisotropic Steel Processed by Selective Laser Melting  

NASA Astrophysics Data System (ADS)

For additive manufacturing of metals, selective laser melting can be employed. The microstructure evolution is directly influenced by processing parameters. Employing a high energy laser system, samples made from austenitic stainless steel were manufactured. The microstructure obtained is characterized by an extremely high degree of anisotropy featuring coarse elongated grains and a <001> texture alongside the build direction during processing. Eventually, the anisotropy of the microstructure drastically affects the monotonic properties of the current material.

Niendorf, Thomas; Leuders, Stefan; Riemer, Andre; Richard, Hans Albert; Tröster, Thomas; Schwarze, Dieter

2013-08-01

145

Microstructural Developments and Tensile Properties of Lean Fe-Mn-Al-C Lightweight Steels  

NASA Astrophysics Data System (ADS)

Concepts of Fe-Al-Mn-C-based lightweight steels are fairly simple, but primary metallurgical issues are complicated. In this study, recent studies on lean-composition lightweight steels were reviewed, summarized, and emphasized by their microstructural development and mechanical properties. The lightweight steels containing a low-density element of Al were designed by thermodynamic calculation and were manufactured by conventional industrial processes. Their microstructures consisted of various secondary phases as ?-carbide, martensite, and austenite in the ferrite matrix according to manufacturing and annealing procedures. The solidification microstructure containing segregations of C, Mn, and Al produced a banded structure during the hot rolling. The (ferrite + austenite) duplex microstructure was formed after the annealing, and the austenite was retained at room temperature. It was because the thermal stability of austenite nucleated from fine ?-carbide was quite high due to fine grain size of austenite. Because these lightweight steels have outstanding properties of strength and ductility as well as reduced density, they give a promise for automotive applications requiring excellent properties.

Sohn, S. S.; Lee, S.; Lee, B.-J.; Kwak, J.-H.

2014-09-01

146

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

147

High-Mn steel weldment mechanical properties at 4 K  

SciTech Connect

Advanced high-field superconducting magnets of the next generation of magnetic confinement fusion devices will require structural alloys with high yield strength and high toughness at cryogenic temperatures. Commercially available alloys used in the current generation of magnets, such as 300 series stainless steels, do not have the required properties. N-strengthened, high-Mn alloys meet base plate requirements in the as-rolled condition. However, the property changes associated with weld microstructural and chemical changes in these alloys have not been well characterized. In this work welding induced cryogenic mechanical property changes of an 18Mn-16Cr-5Ni-0.2N alloy are correlated with as-solidified weld microstructures and chemistries. 30 refs., 12 figs., 3 tabs.

Chan, J.W.; Sunwoo, A.J.; Morris, J.W. Jr.

1988-06-01

148

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

Microsoft Academic Search

This study was aimed at developing low-alloy steels for nuclear reactor pressure vessels by investigating the effects of alloying\\u000a elements on mechanical and fracture properties of base metals and heat-affected zones (HAZs). Four steels whose compositions\\u000a were variations of the composition specification for SA 508 steel (class 3) were fabricated by vacuum-induction melting and\\u000a heat treatment, and their tensile properties

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

2001-01-01

149

Promoting isothermal martensite formation by high temperature heat treatments in a precipitation hardening austenitic stainless steel  

E-print Network

hardening austenitic stainless steel David San Martín* and Carlos García-Mateo MATERALIA Group, DeptPromoting isothermal martensite formation by high temperature heat treatments in a precipitation mechanical properties, the steel investigated (12Cr-9Ni-4Mo-2Cu-1Ti) is solution treated and cooled down

Cambridge, University of

150

Tribological properties of plasma and pulse plasma nitrided AISI 4140 steel  

Microsoft Academic Search

Plasma nitriding is usually used for ferrous materials to improve their surface properties. Knowledge of the properties of thin surface layers is essential for designing engineering components with optimal wear performance. In our study, we investigated the microstructural, mechanical and tribological properties of plasma- and pulse plasma-nitrided AISI 4140 steel in comparison to hardened steel. The influence of nitriding case

B Podgornik; J Vižintin; V Leskovšek

1998-01-01

151

Investigation of microstructure and properties of a Ni–Mo martensitic stainless steel  

Microsoft Academic Search

Martensitic stainless steels are widely used for their good mechanical properties in combination with satisfactory corrosion resistance. However, in recent times the need for excellent properties in specific applications (for example self-drilling and -tapping screws) has led to the research of significant performance improvements of these steels. In this paper, the heat treatment optimization, the mechanical and corrosion properties of

I. Calliari; M. Zanesco; M. Dabalà; K. Brunelli; E. Ramous

2008-01-01

152

A SURVEY OF THE STRUCTURAL PROPERTIES OF SOME HIGH STRENGTH SHEET STEELS  

Microsoft Academic Search

Presented at the Fifth Meeting of the Structures and Materials Panel, ; Apr. 24 to 27, 1957, in Oslo, Norway. This paper deals primarily with the ; structural properties of the sheet steels; however, a brief strength-weight ; evaluation of steel, titanium, and aluminum is made for purposes of orientation. ; The heat-treatable stainless steels which are specifically covered are

Melcon

1957-01-01

153

Kawasaki Steel Giho, Vol. 17, No. 3, 1985.  

National Technical Information Service (NTIS)

Table of Contents: Manufacturing process and properties of stainless steels developed by Kawasaki Steel; Progress of stainless steel production by top and bottom blown converter; Production of high grade stainless steels; New equipment for quality improve...

1985-01-01

154

Deformation behavior of high speed steel/low Carbon steel composite with harmonic structure by MM/SPS process  

NASA Astrophysics Data System (ADS)

The harmonic-structured composite that consists of a network fine grain region with a high speed steel and a dispersed coarse grain region with a low carbon steel was fabricated prepared using a mechanical milling, which is one of the severe plastic deformation method, and spark plasma sintering process. The microstructure and mechanical properties harmonic- structured composite compact were evaluated by a scaning electron microscope and a tensile test, respectively. The harmonic-structured composite exhibited high strength and enough ductility compared with a conventional particle-dispersed composite with the same weight ratio of high speed steel/low carbon steel. The microstructure observation of harmonic-structured composite revieals that the superior elongation of the harmonic-structured composite is attributed to the plastic deformation around the cracks which initiate at the network area.

Tsuzuki, Y.; Fujiwara, H.; Miyamoto, H.; Ameyama, K.

2014-08-01

155

Mechanical properties and fracture toughness of rail steels and thermite welds at low temperature  

NASA Astrophysics Data System (ADS)

Brittle fracture occurs frequently in rails and thermite welded joints, which intimidates the security and reliability of railway service. Railways in cold regions, such as Qinghai-Tibet Railway, make the problem of brittle fracture in rails even worse. A series of tests such as uniaxial tensile tests, Charpy impact tests, and three-point bending tests were carried out at low temperature to investigate the mechanical properties and fracture toughness of U71Mn and U75V rail steels and their thermite welds. Fracture micromechanisms were analyzed by scanning electron microscopy (SEM) on the fracture surfaces of the tested specimens. The ductility indices (percentage elongation after fracture and percentage reduction of area) and the toughness indices (Charpy impact energy A k and plane-strain fracture toughness K IC) of the two kinds of rail steels and the corresponding thermite welds all decrease as the temperature decreases. The thermite welds are more critical to fracture than the rail steel base metals, as indicated by a higher yield-to-ultimate ratio and a much lower Charpy impact energy. U71Mn rail steel is relatively higher in toughness than U75V, as demonstrated by larger A k and K IC values. Therefore, U71Mn rail steel and the corresponding thermite weld are recommended in railway construction and maintenance in cold regions.

Wang, Yuan-qing; Zhou, Hui; Shi, Yong-jiu; Feng, Bao-rui

2012-05-01

156

Hardening of aged duplex stainless steels by spinodal decomposition.  

PubMed

Mechanical properties, such as hardness and impact toughness, of ferrite-containing stainless steels are greatly affected by long-term aging at intermediate temperatures. It is known that the alpha-alpha' spinodal decomposition occurring in the iron-chromium-based ferrite is responsible for this aging susceptibility. This decomposition can be characterized unambiguously by atom probe analysis, allowing comparison both with the existing theories of spinodal decomposition and the evolution of some mechanical properties. It is then possible to predict the evolution of hardness of industrial components during service, based on the detailed knowledge of the involved aging process. PMID:15233853

Danoix, F; Auger, P; Blavette, D

2004-06-01

157

Effect of welding process on the microstructure and properties of dissimilar weld joints between low alloy steel and duplex stainless steel  

NASA Astrophysics Data System (ADS)

To obtain high-quality dissimilar weld joints, the processes of metal inert gas (MIG) welding and tungsten inert gas (TIG) welding for duplex stainless steel (DSS) and low alloy steel were compared in this paper. The microstructure and corrosion morphology of dissimilar weld joints were observed by scanning electron microscopy (SEM); the chemical compositions in different zones were detected by energy-dispersive spectroscopy (EDS); the mechanical properties were measured by microhardness test, tensile test, and impact test; the corrosion behavior was evaluated by polarization curves. Obvious concentration gradients of Ni and Cr exist between the fusion boundary and the type II boundary, where the hardness is much higher. The impact toughness of weld metal by MIG welding is higher than that by TIG welding. The corrosion current density of TIG weld metal is higher than that of MIG weld metal in a 3.5wt% NaCl solution. Galvanic corrosion happens between low alloy steel and weld metal, revealing the weakness of low alloy steel in industrial service. The quality of joints produced by MIG welding is better than that by TIG welding in mechanical performance and corrosion resistance. MIG welding with the filler metal ER2009 is the suitable welding process for dissimilar metals jointing between UNS S31803 duplex stainless steel and low alloy steel in practical application.

Wang, Jing; Lu, Min-xu; Zhang, Lei; Chang, Wei; Xu, Li-ning; Hu, Li-hua

2012-06-01

158

Relationships between tensile and fracture mechanics properties and fatigue properties of large plastic mould steel blocks  

Microsoft Academic Search

Moulds for plastic automotive components such as bumpers and dashboards are usually machined from large pre-hardened steel blocks. Due to their dimensions, the heat treatment produces mixed microstructures, continuously varying with the distance from the quenched surface, at which fracture toughness and fatigue properties are not well known and generally lower than those corresponding to a fully quenched and tempered

Donato Firrao; Paolo Matteis; Giorgio Scavino; Graziano Ubertalli; Maria Giuseppina Ienco; Maria Rosa Pinasco; Enrica Stagno; Riccardo Gerosa; Barbara Rivolta; Antonio Silvestri; Giuseppe Silva; Andrea Ghidini

2007-01-01

159

Effect of microstructure on low cycle fatigue properties of ODS steels  

NASA Astrophysics Data System (ADS)

Low cycle fatigue properties at room temperature, 650 °C and 750 °C of three high chromium steels (9%Cr ferritic-martensitic and two 14%Cr ferritic steels) strengthened by oxide dispersion were studied and compared. Cyclic softening/hardening curves, cyclic deformation curves, S-N curves and Coffin-Manson curves are presented together with microstructural observations. Differences in cyclic response, stress level and fatigue life are attributed to differences in the matrix microstructure. The oxide particles stabilize the cyclic response, even if cyclic softening is detected for some experimental conditions. The strength of these steels is discussed in terms of strengthening mechanisms such as grain size effect, particle-dislocations interaction and dislocation density. Comparing three different ODS steels offers an opportunity to tests the contribution of individual mechanisms to the cyclic strength. The reduction of fatigue life in one of the ferritic steels is explained by the presence of large grains, facilitating the fatigue crack nucleation and the early growth.

Kubena, Ivo; Fournier, Benjamin; Kruml, Tomas

2012-05-01

160

Properties of copper–stainless steel HIP joints before and after neutron irradiation  

Microsoft Academic Search

The tensile and fracture behaviour of CuCrZr and CuAl25 IG0 alloys joint to 316L(N) stainless steel by hot isostatic pressing (HIP) have been determined in unirradiated and neutron-irradiated conditions. The tensile and fracture behaviour of copper alloy HIP joint specimens are dominated by the properties of the copper alloys, and particularly, by the strength mismatch and mismatch in strain hardening

S. Tahtinen; A. Laukkanen; B. N. Singh; P. Toft

2002-01-01

161

Influence of Zn Coating on Interfacial Reactions and Mechanical Properties During Laser Welding-Brazing of Mg to Steel  

NASA Astrophysics Data System (ADS)

To investigate the influence of Zn coating on the joining of magnesium alloy AZ31 to Zn-coated steel, dissimilar metal joining both with and without Zn coating was performed by the laser welding-brazing (LWB) process. Welding characteristics including joint appearance, identification of interfacial reaction layers, and mechanical properties were comparatively studied. The results indicated that the presence of Zn coating promoted the wetting of liquid filler wire on the steel substrate. Heterogeneous interfacial reaction layers formed along the interface between the Mg alloy and Zn-coated steel, whereas no distinct reaction layer and increased concentration of Al were identified at the interface between the Mg alloy and noncoated steel. The maximum tensile-shear strength of Mg/steel lap joint with Zn coating reached 180 N/mm, which was slightly higher than that achieved without Zn coating (160 N/mm). Failure of joint in both cases occurred at the interface; however, the fracture mode was found to differ. For Zn-coated steel, the crack propagated along the Mg-Zn reaction layer and Fe-Al phase, with little Mg-Zn reaction phases remaining on the steel side. As for noncoated steel, some remnants of the seam adhered to the steel substrate.

Li, Liqun; Tan, Caiwang; Chen, Yanbin; Guo, Wei; Hu, Xinbin

2012-12-01

162

Surface conditioning by reactive gases during continuous annealing of sheet steel  

Microsoft Academic Search

The focus of this work is to change surface chemistry and properties without deteriorating the bulk behaviour of deep-drawing steels. Therefore, possibilities and limits of surface modification by reactive gases such as CO–H2–N2 and NH3–H2–N2 atmospheres during continuous annealing of interstitial free (IF) steel grades were investigated. By this, the surface hardness, the bake-hardening properties, the proneness to secondary work

M Ahrens; W Bleck; J Staudte

2001-01-01

163

Fabrication of sintered steel wire mesh and its compressive properties  

Microsoft Academic Search

Porous steel wire mesh with open porosities of 33.90–56.27% and pore sizes of 25–1300?m has been prepared by metallurgical route. The porous morphologies and porosities of the wire mesh have been investigated in terms of forming pressure, sintering temperature and sintering holding time. The pore size distribution in the as-prepared samples has been determined by means of metallographic statistic measurement.

P. Liu; G. He; L. H. Wu

2008-01-01

164

Effect of Reverse Austenite on the Cryogenic Tensile Properties of 0Cr13Ni4Mo Martensitic Steel  

Microsoft Academic Search

Reverse austenite and its effect on the cryogenic tensile properties in the temperature range of 20 °C to -196 °C in 0Cr13Ni4Mo steel were investigated by electron microscopy, X-ray diffraction and tensile tests. Different amounts of reverse austenite were obtained by controlling tempering temperatures. It was revealed that good cryogenic ductility of the steel was obtained due to the existence

X. Y. Li; Y. Y. Song; Y. Y. Li

2008-01-01

165

Austenite stability and its influence on mechanical properties of 18-8 stainless steel at cryogenic temperatures. [SS 304LN  

Microsoft Academic Search

Stress\\/strain induced martensitic transformation has been found to play an important role on the mechanical properties of metastable austenitic stainless steels. Typical two-stage stress-strain curves were observed for AISI 304L and 304LN stainless steels containing 18% Cr and 8%Ni. The martensite phase induced in the high-work-hardening stage was found, by transmission electron microscopy, to be accommodated by mechanical twinning. The

1983-01-01

166

Properties of copper?stainless steel HIP joints before and after neutron irradiation  

NASA Astrophysics Data System (ADS)

The tensile and fracture behaviour of CuCrZr and CuAl25 IG0 alloys joint to 316L(N) stainless steel by hot isostatic pressing (HIP) have been determined in unirradiated and neutron-irradiated conditions. The tensile and fracture behaviour of copper alloy HIP joint specimens are dominated by the properties of the copper alloys, and particularly, by the strength mismatch and mismatch in strain hardening capacities between copper alloys and stainless steel. The test temperature, neutron irradiation and thermal cycles primarily affect the copper alloy HIP joint properties through changing the strength mismatch between the base alloys. Changes in the loading conditions i.e. tensile, bend ( JI) and mixed-mode bend ( JI/ JII) lead to different fracture modes in the copper alloy HIP joint specimens.

Tähtinen, S.; Laukkanen, A.; Singh, B. N.; Toft, P.

2002-12-01

167

Enhancing the vibration reduction ability of concrete by using steel reinforcement and steel surface treatments  

SciTech Connect

The vibration reduction ability of mortar, as expressed by the loss modulus under dynamic flexure (0.2--1.0 Hz), was increased by three (or more) orders of magnitude upon the embedment of steel rebars in the mortar, mainly due to the increase in the vibration damping capacity. By sandblasting the steel rebars, the loss modulus was increased by up to 91%, relative to the values obtained by using as-received rebars, due to the increase in the damping capacity. Surface treatment of the steel rebars by ozone had negligible effect on the loss modulus. The damping capacity was comparably enhanced by steel addition and silica fume addition.

Wen, S.; Chung, D.D.L.

2000-02-01

168

The impact fatigue properties of iron and steel  

NASA Astrophysics Data System (ADS)

When a specimen or component is subjected to repeated impacts it may develop a crack or cracks and eventually fracture. It is then said to have failed by impact fatigue. The strain-rate involved in impact fatigue is about 10 3 s -1 which is substantially higher than the strain-rate usually used in a conventional fatigue or tensile test. Because of this, an iron or steel specimen undergoing impact fatigue has an unusually high ultimate tensile strength and ductile-brittle transition temperature. This can explain some of the main features of impact fatigue behavior such as the high endurance relative to conventional fatigue for a given stress level, and the tendency to exhibit cleavage rather than a ductile fracture mode. Impact fatigue characteristics may be enhanced by surface hardening techniques such as carburizing, nitriding and steel shot bombardment. The effects of corrosive environments on impact fatigue have not yet been explored.

Johnson, Alan A.; Storey, Randall J.

2007-12-01

169

Microstructure and properties of vacuum melted high cobalt and cobalt-free maraging steels  

Microsoft Academic Search

Purpose: Steel cleanliness, microstructure and fracture mode have been studied, with the aim of enhancing mechanical properties and toughness of the high cobalt and cobalt-free maraging steels. Design\\/methodology\\/approach: To fully evaluate all relevant metallurgical factors affecting steel mechanical properties and toughness, broad range of the experimental techniques was used: quantitative metallography, X-ray diffraction, TEM and SEM fractography. Findings: Purity of

S. J. Pawlak

170

Residual elements have significant effects on the elevated-temperature properties of austenitic stainless steel welds  

Microsoft Academic Search

The influence of various residual elements on the elevated-temperature properties of austenitic stainless steel welds was investigated. Included in this investigation are the effects of B, P, Ti, C, S, and Si. This work is aimed at developing austenitic stainless steel weld materials with enhanced elevated-temperature properties. The materials investigated in this program include types 308, 316, 16-8-2 stainless steel

D. P. Edmonds; R. T. King; G. M. Goodwin

1977-01-01

171

The effect of molybdenum on high-temperature properties of 9 pct Cr steels  

Microsoft Academic Search

Heat-resistant 9 Cr steels with 1, 2, and 3 pct Mo were tested for mechanical properties, weldability, and creep-rupture properties.\\u000a The elevated-temperature and rupture strengths increase with increasing molybdenum content. While the 9 Cr-1 Mo steel is martensitic\\u000a and is precipitation strengthened with carbides, the 9 Cr-2 Mo and 9 Cr-3 Mo steels receive added benefits from precipitation\\u000a of Laves

P. J. Grobner; W. C. Hagel

1980-01-01

172

The effect of molybdenum on high-temperature properties of 9 pct Cr steels  

Microsoft Academic Search

Heat-resistant 9 Cr steels with 1, 2, and 3 pct Mo were tested for mechanical properties, weldability, and creep-rupture properties. The elevated-temperature and rupture strengths increase with increasing molybdenum content. While the 9 Cr-1 Mo steel is martensitic and is precipitation strengthened with carbides, the 9 Cr-2 Mo and 9 Cr-3 Mo steels receive added benefits from precipitation of Laves

P. J. Grobner; W. C. Hagel

1980-01-01

173

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

174

Relaxation properties of prestressing steels for concrete reactor vessels. [HTGR  

Microsoft Academic Search

The effects of temperature, initial tension, and load duration upon relaxation of prestressing steels are discussed, and results of relaxation tests performed by General Atomic Company are presented in the report. The tests were conducted at temperatures of 34° to 93°C (93° to 200°F) on 27.9-m (91.5-ft) long tendons made with seven 12.7-mm (0.5-in.) low-relaxation strands from Florida Wire and

Nicolayeff

1978-01-01

175

Structure and properties of plasma-nitrided stainless steel  

Microsoft Academic Search

A series of plasma-nitriding experiments has been conducted on AISI 304L austenitic stainless steel at temperatures ranging from 400 to 600 °C using a pulsed d.c. plasma with various pulse duration\\/repetition ratios in an N2?H2 gas mixture. The structure and composition of the plasma-nitrided surface layer were analysed by means of X-ray diffraction (XRD), scanning electron microscopy, X-ray photoelectron spectroscopy

E. Menthe; K.-T. Rie; J. W. Schultze; S. Simson

1995-01-01

176

Protective properties of redox polymer film deposited on stainless steel  

Microsoft Academic Search

We propose a novel composite organic-inorganic coating in the form of a redox polymer film for protection of stainless steel against general corrosion in strong acid medium (2 M H 2SO 4). We utilize an anion exchange polymer, protonated poly(4-vinylpyridine), into which hexacyanoferrate anions have been introduced. Owing to the presence of Fe(CN) 6 3-\\/4- at the interface formed by the

Mariusz T. Galkowski; Pawel J. Kulesza; Krzysztof Miecznikowski; Malgorzata Chojak; Henryk Bala

2004-01-01

177

Properties of molten synthetic slag used for heating steel  

Microsoft Academic Search

1.The carryout of slag is larger than the carryout of salts, but can be reduced substantially by shaking the parts above the bath.2.The distortion resulting from quenching is almost the same after heating in a slag bath or salt bath.3.No attack on the surface of steel parts at operating temperatures was noted for slag baths, while a notable attack occurred

E. I. Frumin; N. K. Bizik; V. I. Makhnenko

1971-01-01

178

Structure and properties of carburized martensite stainless steels  

Microsoft Academic Search

1.High hardness and sufficient case depth are produced on martensitic stainless steels by carburizing at 950–1000°C. Fine martensite and evenly distributed dispersed carbides are formed in the case.2.Carburizing above 1000°C results in an austenite zone in the diffusion coating with a coarse carbide network in the grain boundaries, leading to cracks during cooling from carburizing temperature and subsequent quenching.

V. I. Belyakova; M. F. Alekseenko

1969-01-01

179

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.

180

Effect of tempering temperature on properties of 00Cr16Ni5Mo stainless steel  

SciTech Connect

Specimens of 00Cr16Ni5Mo low carbon martensitic stainless steel were normalized at 1000 deg. C followed by tempering at 525 deg. C, 550 deg. C, 575 deg. C, 600 deg. C and 625 deg. C. After heat treatment, mechanical properties and pitting potential were determined through tensile, impact and electrochemical polarization tests. The results showed that the samples tempered at 550 deg. C and 600 deg. C for 2 h had an excellent combination of tensile strength, elongation, impact energy, hardness and corrosion resistance. Scanning electron microscopy, and X-ray diffraction examinations were conducted. These revealed that the properties of the steel were affected by the structure of the lath martensite, {delta}-ferrite, retained austenite and carbides.

Qin, B. [Research Institute for Stainless Steel, R and D Center, Baoshan Iron and Steel Co., Ltd. Shanghai, 201900 (China)], E-mail: qinbin@baosteel.com; Wang, Z.Y.; Sun, Q.S. [Research Institute for Stainless Steel, R and D Center, Baoshan Iron and Steel Co., Ltd. Shanghai, 201900 (China)

2008-08-15

181

INFLUENCE OF DEEP CRYOGENIC TREATMENT ON THE PROPERTIES OF CONVENTIONAL AND PM HIGH SPEED STEELS  

Microsoft Academic Search

The influence of Deep Cryogenic Treatment (DCT) on the properties of four wrought and PM high speed steels was investigated. Hardness and (apparent) fracture toughness Ka were measured to highlight the possible influence of DCT carried out before and after tempering. Dry sliding wear tests were carried using a block on disc configuration. The properties of the two wrought steels,

M. Pellizzari

182

Design-relevant mechanical properties of 316-type steels for superconducting magnets  

NASA Astrophysics Data System (ADS)

Interest in austenitic alloys for superconducting magnet structures has led to an expanded database for the 316-type stainless steels. We review the mechanical property behaviour of these steels in wrought, cast, and welded forms at liquid helium temperature (4 K), focussing mainly on fracture mechanics data. Magnetic and elastic property behaviour and design-related information are included.

Tobler, R. L.; Nishimura, A.; Yamamoto, J.

183

Toughness and fatigue properties of martensitic stainless steels for nuclear applications  

Microsoft Academic Search

The use of high-strength stainless steels in pressurized water reactors may allow reductions in weight and cost of some components. As a preliminary requirement to the use of these materials, a good knowledge of their mechanical properties and corrosion resistance is needed. In this study, the toughness and fatigue properties of five low-carbon martensitic stainless steel grades were determined. The

D. Wayner; G. Baudry; Y. Bonningue; D. Chavaillard; M. Cozar; J. P. Meyzaud

1985-01-01

184

Effect of vanadium and other carbide-forming elements on the properties of rotor steels  

Microsoft Academic Search

It is important to solve the problem of obtaining a fine-grain structure and the related improvement in the properties of rotor steels. Accordingly, we have investigated the effect of additives of vanadium and also zirconium, niobium, and tantalum on the properties of 25Kh2N2M rotor steel.

I. A. Borisov

1994-01-01

185

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

186

The effect of irradiation on the mechanical properties of ferritic-martensitic steels  

Microsoft Academic Search

In this article the influence of irradiation on the tensile, toughness and in-pile creep properties of ferritic-martensitic stainless steels is reviewed in view of their possible application as structural materials for fusion reactors.For irradiations below 400°C, rather low doses of 10 to 20 dpa cause already strong hardening and embrittlement as shown by the reduced tensile ductility and impact strength.

W. Vandermeulen; M. Snykers

1987-01-01

187

Inhibiting properties and adsorption of some thioamides on mild steel in sulphuric acid solutions  

Microsoft Academic Search

The inhibiting properties and adsorption behaviour of thioacetamide (TAA), thiobenzamide (TBA) and thiocinnamamide (TCA) on\\u000a mild steel in sulphuric acid solution were studied by gravimetric, potentiodynamic polarization and electrochemical impedance\\u000a spectroscopy (EIS) measurements. TBA and TCA were found to be mixed type inhibitors providing good corrosion inhibition. Different\\u000a mechanisms of adsorption and corrosion inhibition were observed for the tested thioamides.

E. Lazarova; G. Petkova; T. Iankova; L. Ivan; G. Neikov

2008-01-01

188

Effect of nitrogen alloying and the electroslag refining process on the properties of AISI M41 steel  

NASA Astrophysics Data System (ADS)

Nitrogen produces very beneficial effects in high-speed steel and can therefore be regarded as a significant alloying element in ferrous materials. In order to attain the goal of this study, to investigate the effect of nitrogen alloying and the electroslag refining (ESR) process on the properties of AISI M41 steel, two high-speed steels were melted in an air induction furnace (IF). The first one is a standard AISI M41 high-speed steel. The second one is nitrogen-alloyed M41. The produced ingots were used as consumable electrodes in ESR under three different CaF2-based fluxes. The steel produced from the IF and ESR was heat treated. Hardness, secondary hardness, and microstructure were also studied. It was concluded that both ESR and nitrogen alloying improve the hardness profile of the quenched-tempered high-speed steels. The highest secondary hardness and highest softening resistance were attained by ESR of high-nitrogen high-speed steel (M41N) under CaF2/CaO/Al2O3: 55/30/15 slag. The ESR improves the shape, size, and distribution of precipitates in the produced ingot. Quenching and tempering treatment conditions the retained austenite that is present in the as-cast steel by precipitation of carbide and forming martensite on cooling to room temperature.

Mattar, Taha; El Fawakhry, Kamal; Halfa, Hossam; El Demerdash, Mahmoud

2006-12-01

189

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

190

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 500°C. 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 500°C 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 1100°C 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 (1200-1150°C), annealing of the steels at temperatures no less than 1150°C (for 1 h) with water quenching and tempering at 500°C for 2 h are recommended.

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

2012-05-01

191

Growth and properties of Cr-rich thick and porous oxide films on Type 304 stainless steel formed by square wave potential pulse polarisation  

Microsoft Academic Search

Extraordinarily thick and porous oxide films are obtained on Type 304 stainless steel. The material was polarised in 5 kmolm?3 H2SO4 solution at 50–80°C with applied potential modulated as square wave. The films formed are classified into two types according to applied potentials. For the anodic type, Fe and Cr actively dissolve at the lower potential of the square wave,

Shinji Fujimoto; Kiyoshi Tsujino; Toshio Shibata

2001-01-01

192

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

Microsoft Academic Search

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\\/mm2 at the substrate bias of about ?75 V. In the scratch adhesion test, the critical loads for

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

1998-01-01

193

Elevated Temperature Low Cycle Fatigue Properties of Martensitic Cast Steel  

E-print Network

Abstract — This work investigated the elevated temperature low cycle fatigue (LCF) properties of GX12CrMoVNbN9–1 (GP91) cast steel. Fatigue tests were performed for five levels of total strain amplitude ?ac and temperature of 400, 550 and 600oC. In addition, the preliminary results from tensile test were presented. Strong cyclic softening was observed in all fatigue tests at elevated temperatures without stabilization period of loop parameters. The plastic strain amplitudes during cyclic strain loading were measured and correlated with the fatigue lifetime using Coffin – Mason – Basquin plots at each test temperature. The fatigue lifetime decreased as the temperature test increased. The temperature effect on lifetime was more pronounced at low strain amplitudes. Index Term— estimation, Cast.

Stanis?aw Mrozi?ski; Grzegorz Gola?ski

194

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

195

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

196

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

197

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

198

Comparative cavitation erosion test on steels produced by ESR and AOD refining  

NASA Astrophysics Data System (ADS)

Cavitation erosion studies of steels produced by Electroslag Refining (ESR) and Argon Oxygen Decarburization (AOD refining) have been carried out. The experiments were conducted using the modified ultrasonically induced cavitation test method. Erosion rates were measured and the morphology of damages under cavitation action was studied by scanning electron microscopy and optical microscopy techniques. The present work is aimed at understanding the cavitation erosion behaviour of electroslag refined steel (ESR) compared with the steel produced by Argon Oxygen Decarburization (AOD refining), commonly used in the production of hydraulic machinery parts (Pelton blades). The results exhibited lower cavitation rate of ESR steel compared with AOD steel, as a consequence of its better mechanical properties and homogeneous and fine-grained microstructure.

Doj?inovi?, M.

2011-09-01

199

Experimental research on the mechanical property of prestressing steel wire during and after heating  

Microsoft Academic Search

The mechanical property of prestressing steel wire during and after heating is the key factor in the design of fire resistance\\u000a and after-fire damage evaluation of prestressed structures. Tensile experiment of 16 prestressing steel wires (f\\u000a ptk = 1770 N\\/mm2, d = 5 mm, low relaxation of stress) at high temperature and tensile experiment of 14 prestressed steel wires after

Wenzhong Zheng; Qiong Hu; Haoyu Zhang

2007-01-01

200

Study on fatigue property of a new 2.8 GPa grade maraging steel  

Microsoft Academic Search

A new 2.8GPa grade maraging steel was developed in the present work and the tension–tension fatigue property of the steel was studied after peak-aging treatment. The results showed that the steel could reach an ultimate tensile strength of 2760MPa, a fracture toughness of 31.6MPam1\\/2, and a fatigue limit of 1150MPa at stress ratio of 0.1. It was revealed that the

Wei Wang; Wei Yan; Qiqiang Duan; Yiyin Shan; Zhefeng Zhang; Ke Yang

2010-01-01

201

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

202

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

203

The influence of Cr content on the mechanical properties of ODS ferritic steels  

NASA Astrophysics Data System (ADS)

The present investigation aimed at researching the mechanical properties of the oxide dispersion strengthened (ODS) ferritic steels with different Cr content, which were fabricated through a consolidation of mechanical alloyed (MA) powders of 0.35 wt.% nano Y2O3 dispersed Fe-12.0Cr-0.5Ti-1.0W (alloy A), Fe-16.0Cr-0.5Ti-1.0W (alloy B), and Fe-18.0Cr-0.5Ti-1.0W (alloy C) alloys (all in wt.%) by hot isostatic pressing (HIP) with 100 MPa pressure at 1150 °C for 3 h. The mechanical properties, including the tensile strength, hardness, and impact fracture toughness were tested by universal testers, while Young's modulus was determined by ultrasonic wave non-destructive tester. It was found that the relationship between Cr content and the strength of ODS ferritic steels was not a proportional relationship. However, too high a Cr content will cause the precipitation of Cr-enriched segregation phase, which is detrimental to the ductility of ODS ferritic steels.

Li, Shaofu; Zhou, Zhangjian; Jang, Jinsung; Wang, Man; Hu, Helong; Sun, Hongying; Zou, Lei; Zhang, Guangming; Zhang, Liwei

2014-12-01

204

A maraging steel produced by the powder metallurgy method  

Microsoft Academic Search

1.In a study into the effect of sintering temperature and duration on the density, microhardness, and martensite lattice constant of a powder metallurgical maraging steel and also on the character of formation of its micro structure, the following mechanical properties were attained after sintering and aging: sB=101 kg\\/mm2, s0.2=98 kg\\/mm2, d=4%, ?=12%, aH=7.9 kg-m\\/cm2, and HRC=25–27.2.The influence exerted by plastic

V. N. Antsiferov; Yu. M. Kolbenev

1972-01-01

205

Fatigue Properties of Heat-Treated 30MSV6 Vanadium Microalloyed Steel  

NASA Astrophysics Data System (ADS)

In the present study, 30MSV6 microalloyed steel was heat treated under different conditions, and the relation between its microstructure and mechanical properties was investigated. Scanning electron microscopy and transmission electron microscopy were used to characterize the microstructure of the heat-treated steel, and the effect of microstructure on tensile strength and fatigue behavior was determined. Microstructural analysis indicated that precipitates were formed at different sites such as grain boundaries and sub-grain boundaries. Furthermore, microstructural studies accompanied by the evaluation of mechanical properties revealed that the optimal heat treatment cycle of 30MSV6 microalloyed steel involved austenitization at 1223 K for 1 h and cooling in air to room temperature, followed by aging at 873 K for 1.5 h. The optimal heat treatment cycle resulted in significant improvement in the fatigue strength, tensile strength, and ductility because of the development of a uniform distribution of fine precipitates in a refined microstructure. The fatigue limit under optimum conditions (~384 MPa) was greater than that under other conditions (~321 and 312 MPa).

Hajisafari, M.; Nategh, S.; Yoozbashizadeh, H.; Ekrami, A.

2013-03-01

206

Factors Affecting on Mechanical Properties of Soft Martensitic Stainless Steel Castings  

Microsoft Academic Search

This paper details the factors affecting mechanical properties of soft martensitic stainless steel castings that have lower carbon contents and increased nickel contents of up to 6% compared with normal martensitic stainless steel castings. The effect of alloying elements and impurities on the microstructural features and tempering characteristics was considered in detail, with special reference to reverted austenite and temper

Yoshitaka Iwabuchi

2003-01-01

207

Deep cryogenic treatment of AISI 302 stainless steel: Part I – Hardness and tensile properties  

Microsoft Academic Search

The effects of deep cryogenic treatment (DCT) on the static mechanical properties of the AISI 302 austenitic stainless steel were investigated through experimental testing. The results of the tensile and hardness tests are discussed and compared to data and microstructural observations from the DCT literature concerning the same class of steel. In addition, the influence of two important treatment parameters,

Paolo Baldissera

2010-01-01

208

Structure of properties of the heat affected zone of P91 creep resistant steel  

Microsoft Academic Search

This investigation is concerned with the characterisation of actual welded samples of P91 - a 9%Cr heat resisting steel that is widely used for pressure vessels in the power generation industry. Although the creep resistance of the normalised and tempered base steel is excellent, weld fabrication compromises creep performance because of degraded properties in the heat affected zone (HAZ). In

Samsiah Sulaiman

2007-01-01

209

Mechanical properties of cobalt-chromium wires compared to stainless steel and ?-titanium wires  

PubMed Central

Background: Previous studies have reported on mechanical properties of different orthodontic wires. However, there is a paucity of information that comparing the mechanical properties of Blue Elgiloy (BE) when compared to stainless steel and TMA, as finishing wires as received by different companies. Aims: The aim of this study was to evaluate the mechanical properties of BE wires compared to stainless steel (SS) and titanium Molybdenum alloy (TMA) also known as ? titanium as provided by two companies. Materials and Methods: Six 0.016 x 0.022-14mm-samples of each wire were fixed individually to Instron machine and were tested in loading and unloading for three times. The initial load was set for 500 Kg at a speed of 1mm/min and displacement was adjusted for (0.5, 1mm in loading and 0.5 mm unloading at 25°C). Statistics Analysis: Variables were compared between groups by ANOVA test using SPSS statistical software. Results: BE shows comparable forces to SS when loaded 0.5 and showed decreased forces in 1mm loading compared to SS, and higher than TMA. BE also showed no forces at unloading and high deformation. Conclusion: BE from the two companies showed comparable mechanical properties while SS and TMA were different. The deformation of BE and its decreased forces in unloading may limit its clinical use.

Alobeid, Ahmad; Hasan, Malak; Al-Suleiman, Mahmoud; El-Bialy, Tarek

2014-01-01

210

Temperature effects on the mechanical properties of annealed and HERF 304L stainless steel.  

SciTech Connect

The effect of temperature on the tensile properties of annealed 304L stainless steel and HERF 304L stainless steel forgings was determined by completing experiments over the moderate range of -40 F to 160 F. Temperature effects were more significant in the annealed material than the HERF material. The tensile yield strength of the annealed material at -40 F averaged twenty two percent above the room temperature value and at 160 F averaged thirteen percent below. The tensile yield strength for the three different geometry HERF forgings at -40 F and 160 F changed less than ten percent from room temperature. The ultimate tensile strength was more temperature dependent than the yield strength. The annealed material averaged thirty six percent above and fourteen percent below the room temperature ultimate strength at -40 F and 160 F, respectively. The HERF forgings exhibited similar, slightly lower changes in ultimate strength with temperature. For completeness and illustrative purposes, the stress-strain curves are included for each of the tensile experiments conducted. The results of this study prompted a continuation study to determine tensile property changes of welded 304L stainless steel material with temperature, documented separately.

Antoun, Bonnie R.

2004-11-01

211

Strain hardening and plastic instability properties of austenitic stainless steels after proton and neutron irradiation  

NASA Astrophysics Data System (ADS)

Strain hardening and plastic instability properties were analyzed for EC316LN, HTUPS316, and AL6XN austenitic stainless steels after combined 800 MeV proton and spallation neutron irradiation to doses up to 10.7 dpa. The steels retained good strain-hardening rates after irradiation, which resulted in significant uniform strains. It was found that the instability stress, the stress at the onset of necking, had little dependence on the irradiation dose. Tensile fracture stress and strain were calculated from the stress-strain curve data and were used to estimate fracture toughness using an existing model. The doses to plastic instability and fracture, the accumulated doses at which the yield stress reaches instability stress or fracture stress, were predicted by extrapolation of the yield stress, instability stress, and fracture stress to higher dose. The EC316LN alloy required the highest doses for plastic instability and fracture. Plastic deformation mechanisms are discussed in relation to the strain-hardening properties of the austenitic stainless steels.

Byun, T. S.; Farrell, K.; Lee, E. H.; Hunn, J. D.; Mansur, L. K.

2001-10-01

212

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

213

Influence of trace elements and heat treatment on carbide morphology and properties of CD2 steel  

Microsoft Academic Search

The purpose of the current investigation was to develop a modified ledeburite cast die steel with granular carbide, which, different from the conventional ledeburite cast die steel CD-2 with network carbide, had higher strength and toughness. By adding trace elements, grain and eutectic in the steel were refined, with a concomitant increase in divorced eutectic and decrease in segregation of

S. Q. Wang; Q. C. Jiang; X. H. Cui; Z. M. He

1999-01-01

214

Influence of nickel and molybdenum on the phase stability and mechanical properties of maraging steels  

SciTech Connect

The effect of nickel and molybdenum concentrations on the phase transformation and mechanical properties of conventional 10Ni(350) maraging steel has been investigated. Both of these elements act as strong austenite stabilizers. When the concentration of molybdenum or nickel is greater than 7.5 or 24 wt%, respectively, the austenite phase remains stable up to room temperature. In both molybdenum- and nickel-alloyed steels, the austenite phase could be transformed to martensite by either dipping the material in liquid nitrogen or subjecting it to cold working. When 7.5 wt% Mo and 24 wt% Ni were added in combination, however, the austenite phase obtained at room temperature did not transform to martensite when liquid-nitrogen quenched or even when cold rolled to greater than 95% reduction. The aging response of these materials has also been investigated using optical, scanning electron, and scanning transmission electron microscopy.

Ahmed, M.; Nasim, I.; Husain, S.W. (Dr. A.Q. Khan Research Labs., Rawalpindi (Pakistan))

1994-04-01

215

Inhibitory properties of ocean vegetation products in the corrosion of steel  

SciTech Connect

The inhibitory properties of byproducts from the processing of Black Sea red algae Phyllophora nervosa were investigated in solutions of sulfuric and nitric acids, tap water, and sea water. Corrosion tests were conducted gravimetrically on St3, St40, and St60 steels, and on titanium alloy VT-1. Inhibitor effectiveness was measured by corrosion rate, the inhibition coefficient, and the extent of protection. A complete factor matrix was taken. Experimental results were expressed as a partial quadratic equation. The behavior of iron ions in the corrosion process was assessed. Tests established that the byproducts, referred to as inhibitor IFKhI, can be used in steel pickling treatments in sulfuric acid solutions over a wide temperature range.

Popelyukh, G.M.; Talavira, L.I.

1988-05-01

216

Wounding properties of steel pellets with different velocities and quality on soft tissue of dogs.  

PubMed

The characteristics of the soft-tissue wounds of the hind legs of 155 dogs produced by stainless steel spheres with four different masses and at various impact velocities were observed. It was found that when the mass of the spheres was identical, the velocity became the main factor to determine the severity of the damage; when the mass of the spheres was different but their kinetic energy was similar, then a smaller but faster sphere produced more severe damage than a larger but slower one. Shallow but wide and severe wounds usually resulted. The rate of disability of extremities with such wounds was very high. These wounding properties of steel spheres have caused some new problems in the treatment of war injuries. PMID:3339696

Cheng, X Y; Feng, T S; Liu, Y Q; Ma, Y Y; Wu, B J; Fu, R X; Xie, G P; Li, M; Chen, Z C; Wang, D T

1988-01-01

217

Effect of galvanic coatings on the elastic properties and the relaxation stability of thin-spring steel sheet  

Microsoft Academic Search

It was established that the elastic limit of and hydrogen content in steel 65Mn depend on the thickness of the zinc coatings. Hydrogen could not be completely removed from zinc-coated specimens by vacuum heat treatment at admissible temperatures; nor were their properties restored by this treatment. An effective method of eliminating the harmful effect of galvanic coatings on the stress

R. I. Mishkevich; S. Ya. Grilikhes; N. G. Gavrilyuk

1972-01-01

218

Creep-fatigue interaction and related structure property correlations of EUROFER97 steel at 550 °C by decoupling creep and fatigue load  

NASA Astrophysics Data System (ADS)

Mechanical tests have been performed at 550 °C under vacuum on the ferritic-martensitic steel EUROFER97. These experiments included fatigue tests, creep tests and combined creep-fatigue tests. The latter showed significant cyclic softening in the fatigue stage and a remarkable break-down of creep strength in the creep stage. The cyclic softening behaviour was almost identical for all tests and therefore insensitive to the different strain amplitudes. SEM of the specimen's fracture surfaces and free surfaces revealed that networks of coagulated surface cracks formed during creep-fatigue were not failure relevant. TEM imaging displayed a drastic drop in dislocation density, and a considerable formation of precipitates and subgrain-structures in all tests. Pure fatigue led to the strongest reduction of dislocation density, whereas creep-fatigue induced the most pronounced formation of precipitates. Obviously, the internal softening due to prior cycling led to accelerated creep. Hence, a modified damage model for creep-fatigue load cases was proposed.

Vorpahl, C.; Möslang, A.; Rieth, M.

2011-10-01

219

Relationship between Material Properties and Local Formability of DP980 Steels  

SciTech Connect

A noticeable degree of inconsistent forming behaviors has been observed for the 1st generation advanced high strength steels (AHSS) in production, and they appear to be associated with the inherent microstructural-level inhomogeneities for various AHSS. This indicates that the basic material property requirements and screening methods currently used for the mild steels and high strength low alloys (HSLA) are no longer sufficient for qualifying today’s AHSS. In order to establish more relevant material acceptance criteria for AHSS, the fundamental understandings on key mechanical properties and microstructural features influencing the local formability of AHSS need to be developed. For this purpose, in this study, DP980 was selected as model steels and eight different types of DP980 sheet steels were acquired from various steel suppliers. Various experiments were then performed on the eight different DP980 steels such as chemical composition analysis, static tensile test, hole expansion test, channel forming test. Scanning electron microscope (SEM) pictures of the DP980 steels were also obtained, and image processing tools were then adopted to those SEM pictures in order to quantify their various microstructural features. The results show that all DP980 steels show large discrepancy in their performance and that the tensile properties and hole expansion properties of these steels do not correlate with their local formability. According to the results up to date, it is not possible to correlate the microstructural features alone to the macroscopically measured deformation behaviors. In addition to image analysis, other experiments (i.e., nano-indentation test) are also planned to quantify the individual phase properties of the various DP steels.

Choi, Kyoo Sil; Soulami, Ayoub; Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.; Xu, Le; Barlat, Frederic

2012-04-24

220

Mechanical property of a low carbon steel with biomimetic units in different shapes  

NASA Astrophysics Data System (ADS)

Inspired by the superior biomechanical properties of some biological compositions, an attempt to improve the mechanical property of low carbon steel with biomimetic units was made by using a laser remelting process. Three kinds of shapes including 'striation', 'spot' and 'gridding', were chosen for forming the biomimetic units. Microstructure and microhardness examinations demonstrated that desirable microstructural changes and regular hardness distribution were acquired in the units. The results of tensile tests indicated that the biomimetic specimens had an improvement in the strength and ductility simultaneously. The beneficial influence of laser processed biomimetic units on tensile behavior can be attributed to the combined effects of the microstructural characteristics within the unit zone and the stress redistribution derived from the efficient stress transfer. By investigating the variation of plastic deformation in different regions of the specimens, the effect of unit shapes on tensile property was also compared and discussed.

Wang, Chuanwei; Zhou, Hong; Zhang, Zhihui; Zhao, Yu; Cong, Dalong; Meng, Chao; Zhang, Peng; Ren, Luquan

2013-04-01

221

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

222

Comparison of the mechanical strength properties of several high-chromium ferritic steels  

SciTech Connect

A modified 9 Cr-1 Mo ferritic steel has been selected as an alternative material for breeder reactors. Different 9 Cr-1 Mo steels are already being used commercially in UK and USA and a 9 Cr-2 Mo steel (EM12) is being used commercially in France. The 12% Cr steel alloy HT9 is also often recommended for high-temperature service. Creep-rupture data for all six seels were analyzed to yield rupture life as a function of stress, temperature, and lot-to-lot variations. Yield and tensile strength data for the three 9 Cr-1 Mo materials were also examined. All results were compared with Type 304 stainless steel, and the tensile and creep properties of the modified and British 9 Cr-1 Mo materials were used to calculate allowable stress values S/sub 0/ per Section VIII, Division 1 and S/sub m/ per code Case N-47 to section III of the ASME Boiler and Pressure Vessel Code. these values were compared with code listings for American commercial 9 Cr-1 Mo steel, 2 1/4 Cr-1 Mo steel, and Type 304 stainless steel. The conclusion is made that the modified 9 Cr-1 Mo steel displays tensile and creep strengths superior to those of the other ferritic materials examined and is at least comparable to Type 304 stainless steel from room temperature to about 625/sup 0/C. 31 figures.

Booker, M.K.; Sikka, V.K.; Booker, B.L.P.

1981-01-01

223

Influence of Microstructure on Nitriding Properties of Stainless Steel  

Microsoft Academic Search

Very hard and wear-resistant layers are formed after energetic nitrogen insertion into stainless steel. Here, a systematic investigation of the influence of the microstructure is presented. Nitrogen implantation was performed in austenitic, martensitic, and ferritic steels with the samples investigated with respect to formation of expanded phase, nitrogen depth distribution, hardness, and wear. Microstructure strongly affects the diffusion in austenite

Darina Manova; Inga-Maria Eichentopf; Dietmar Hirsch; Stephan Mändl; Horst Neumann; Bernd Rauschenbach

2006-01-01

224

Effects of manufacturing process on impact properties and microstructures of ODS steels  

NASA Astrophysics Data System (ADS)

Oxide dispersion strengthened (ODS) steels are notable advanced alloys with durability to a high-temperature and high-dose neutron irradiation environment because of their good swelling resistance and mechanical properties under neutron irradiation. 9-12Cr-ODS martensite steels have been developed in the Japan Atomic Energy Agency as the primary candidate material for the fast reactor fuel cladding tubes. They would also be good candidates for the fusion reactor blanket material which is exposed to high-dose neutron irradiation. In this work, modification of the manufacturing process of 11Cr-ODS steel was carried out to improve its impact property. Two types of 11Cr-ODS steels were manufactured: pre-mix and full pre-alloy ODS steels. Miniature Charpy impact tests and metallurgical observations were carried out on these steels. The impact properties of full pre-alloy ODS steels were shown to be superior to those of pre-mix ODS steels. It was demonstrated that the full pre-alloy process noticeably improved the microstructure homogeneity (i.e. reduction of inclusions and pores).

Tanno, Takashi; Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Tanaka, Kenya

2014-12-01

225

Structure and properties of half-sections of a crankshaft of 34KhNlM steel produced by electroslag casting  

Microsoft Academic Search

The use of electroslag casting in the production of large diameter crankshafts provides a high-quality structure and a high combination of mechanical properties in the most stressed portions of the crankshaft and particularly in the zone of the neck.

I. E. Blokhin; V. K. Zablotskii; M. M. D'yakov; V. V. Bekhin; P. S. Sergeev

1984-01-01

226

Toughness and fatigue properties of martensitic stainless steels for nuclear applications  

Microsoft Academic Search

The use of high-strength stainless steels in pressurized water reactors may allow reductions in weight and cost of some components.\\u000a As a preliminary requirement to the use of these materials, a good knowledge of their mechanical properties and corrosion\\u000a resistance is needed.\\u000a \\u000a In this study, the toughness and fatigue properties of five low-carbon martensitic stainless steel grades were determined.\\u000a The

D. Wagner; J.-P. Chavaillard; Y. Meyzaud; M. Bonningue; R. Cozar; G. Baudry

1985-01-01

227

Structure and properties of Ni-Cr-Mo-V-rotor steels  

Microsoft Academic Search

on the structure and mechanical properties of rotor steels of the types 25KhN3MFA, 35KhN3MFA, and 12KhN3MFA (Table i). Cobalt, whose addition promotes an increase in steel magnetic induction which is important for turbogenerator rotors, was added to melt E with the aim of studying its effect on mechanical properties. Studies were performed on specimens 70 × 70 × 400 mm

I. A. Borisov; A. M. Shkatova; S. B. Vikhriev

1989-01-01

228

The modeling of structure and properties of carburized low-chromium hypereutectoid steels  

Microsoft Academic Search

Research of carburized high-carbon bearing LH15 (52100) steel is presented. Problems analyzed include thermodynamic and kinetic\\u000a basis of carburizing in two-phase field (austenite-cementite), carbon content influence in diffusive layer on utilization\\u000a properties of the examined steel, and functional carbon content influence on chemical and phase composition of carbonized\\u000a layer. An understanding of these problems enables modeling of functional properties and

M. Przylecka

1996-01-01

229

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

230

Effect of Ce addition on the sensitization properties of stainless steels  

SciTech Connect

Rare earth elements are characterized by significant negative free energy changes for compound formations, such as carbides, sulfides and oxides. It has been reported that the effect of the addition of cerium to the steels, on their corrosion properties, is to form a thermodynamically stable surface film composed of cerium oxide. This reduces the cathodic and anodic reactivity by blocking the reactive surface sites and improves the resistance to pitting and crevice corrosion. The addition of cerium is also reported to have improved the dry oxidation resistance of SS. It has been attributed to the larger atomic size of the rare earth elements with respect to that of iron. The vacancies in the alloy move to the stressed regions adjacent to the rare earth oxides at the metal/oxide interface where they serve as nucleation sites for chromium oxide and also affect the diffusion rate of chromium. These facts indicate that the addition of cerium to the steel affects the surface film properties and improves its resistance to localized corrosion. The effect of the cerium addition on the microstructure of SS has not been reported. In this study, a series of type 316 SS (UNS S31600) containing various amounts of cerium was prepared and the effects of the cerium addition on the sensitization properties were investigated.

Watanabe, Y.; Kain, V.; Tonozuka, T.; Shoji, T.; Kondo, T.; Masuyama, F.

2000-01-01

231

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

232

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

233

Mechanical properties and fracture behavior of ? particle irradiated type 316 stainless steel at high temperature  

NASA Astrophysics Data System (ADS)

The effect of helium on the mechanical properties and fracture behaviors of a type 316 austenitic steel is presented. Helium implantation was performed by 30-MeV ?-particle injection on very small, thin specimens, using a cyclotron accelerator. Average helium content in the He-deposited region was 50 to 2000 appm He. These specimens showed the transition of fracture mode from transgranular to intergranular fracture in elevated temperature tests. The transition temperature decreased with increase in the amount of implanted helium. For example, in the case of 2000 appm and 500 appm He implantation, the transition temperatures were between 773 and 873 K and between 873 and 973 K, respectively.

Miyahara, K.; Itoh, A.; Sakamoto, Y.; Kayano, H.; Hosoi, Y.

1992-09-01

234

Variation of microstructures and mechanical properties in the post-weld heat-treated HAZ of Cu containing HSLA steel welds  

Microsoft Academic Search

The present study focuses on the effect of Cu and post-weld heat treatment (PWHT) on the microstructure and mechanical properties\\u000a in the coarse grained heat affected zone (CGHAZ) of Cu containing high strength low alloy (HSLA) steel welds. For this study,\\u000a HSLA steels with and without Cu were prepared in laboratory. Mechanical properties were estimated by Vickers hardness and\\u000a Charpy

Sanghoon Kim; Jongho Lee; Byoungchul Hwang; Chang Gil Lee; Changhee Lee

2011-01-01

235

Microstructures and mechanical properties of injection molded 17-4PH stainless steel powder with nickel boride additions  

Microsoft Academic Search

This paper describes the sintering of an injection molded 17-4 PH stainless steel with additions of nickel boride (NiB), with the aim of producing high mechanical properties. Boron is evaluated as the best sintering enhancing element in terms of densifying the iron-based materials by formation the liquid phase. Sintered density and mechanical properties were increased with the increased amount of

H. Ö. Gülsoy; S. Salman

2005-01-01

236

Creep properties of austenitic stainless-steel weld metals  

Microsoft Academic Search

The creep behavior of two austeitic stainless-steel weld metals was investigated. Two AISI 316L stainless-steel base plates\\u000a were welded together using the submerged arc-welding process. Creep tests were carried out on the welds at constant load,\\u000a over a stress range of 100 to 400 MPa, and in the temperature range of 600 to 700 ?C. The relationships between stress and

A. Nassour; W. W. Bose; D. Spinelli

2001-01-01

237

Transformations in TRIP-assisted Steels: Microstructure and Properties  

E-print Network

, these steels can be used as front or rear door side-impact bars in a passenger car. 2.8.3 Fatigue resistance The importance of fatigue resistance is obvious for a steel to be used in auto- mobile components that are routinely subjected to cyclic loading [Yan... . . . . . . . . . . . . . . . . . . . . . . . . 33 2.8.2 Crash-worthiness . . . . . . . . . . . . . . . . . . . . . 36 2.8.3 Fatigue resistance . . . . . . . . . . . . . . . . . . . . . 36 v vi CONTENTS 2.8.4 Bake hardening . . . . . . . . . . . . . . . . . . . . . . 38 2.9 Limitations...

Chatterjee, Sourabh

238

Formation Energies and Electronic Properties of Vanadium Carbides Found in High Strength Steel Alloys  

NASA Astrophysics Data System (ADS)

Carbide formation and stabilization in steels is of great interest owing to its effect on the microstructure and properties of the Fe-based alloys. The appearance of carbides with different metal/C ratios strongly depends on the carbon concentration, alloy composition as well as the heat treatment. Strong carbide-forming elements such as Ti, V, and Nb have been used in microalloyed steels; with VC showing an increased solubility in the iron matrix as compared with TiC and NbC. This allows for dissolution of the VC into the steel during heating and fine precipitation during cooling. In addition to VC, the primary vanadium carbide with cubic structure, a wide range of non-stoichiometric compositions VCy with y varying from 0.72 to 0.88, has been observed. This range includes two ordered compounds, V8C7 and V6C5. In this study, first-principles density functional theory (DFT) is employed to examine the stability of the binary carbides by calculating their formation energies. We compare the local structures (atomic coordination, bond distances and angles) and the density of states in optimized geometries of the carbides. Further, the effect of alloying additions, such as niobium and titanium, on the carbide stabilization is investigated. We determine the energetically preferable substitutional atom location in each carbide and study the impurity distribution as well as its role in the carbide formation energy and electronic structure.

Limmer, Krista; Medvedeva, Julia

2013-03-01

239

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

240

Microstructure and Mechanical Properties of a Low Alloyed MnB Cast Steel  

NASA Astrophysics Data System (ADS)

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

Luo, Kaishuang; Bai, Bingzhe

2010-08-01

241

Microstructure and mechanical properties of $alpha;-particle irradiated Cr-Mn and the other stainless steels  

NASA Astrophysics Data System (ADS)

The present work is a study of the effects of helium on the microstructure, mechanical properties and fracture behavior of three kinds of steels, that is, a 12Cr-15Mn (wt%) austenitic steel, a Type 316 austenitic steel and a 9Cr-2Mo ferritic steel. Helium injection was performed using a cyclotron. Helium content was up to 2000 appm He. In the case of the type 316 stainless steel, intergranualr fracture was sometimes observed after tensile testing at room temperature. This material, however, showed only transgranular-ductile fracture at 773 K. The helium implanted (500 appm He) 9Cr-2Mo showed transgranular fracture at room temperature and 773 K. The helium implanted (500 appm He) 12Cr-15Mn also indicated only transgranular fracture by a tensile test at 773 K. In the present work, intergranular fracture was not observed in any of the steels at an elevated temperature of 773 K. Accordingly, this suggests that a high concentration of helium does not necessarily cause the intergranular fracture at a high temperature.

Miyahara, K.; Sakamoto, Y.; Hamada, S.; Kayano, H.; Hosoi, Y.

1991-03-01

242

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

E-print Network

. Verification of rebar corrosion was done by galvanic current, half-cell potential, and electrochemical analysisEarly 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

243

Characterization of the magnetic micro- and nanostructure in unalloyed steels by magnetic force microscopy  

NASA Astrophysics Data System (ADS)

The formation of a cementite phase influences significantly the macroscopic mechanical and magnetic properties of steels. Based on a correlation between mechanical and magnetic properties, mechanical properties as well as the morphology and content of the cementite phase can be inspected by electromagnetic non-destructive testing methods. The influence of the carbon content on bulk magnetic properties of unalloyed steels is studied on a macroscopic scale by hysteresis loop and Barkhausen noise measurements. The micro- and nanostructure is investigated by atomic force microscopy and magnetic force microscopy. Surface topography images and magnetic images of globular cementite precipitates embedded in a ferrite matrix are presented. The size, shape, and orientation of the precipitates influence the domain configuration. Applied external magnetic fields cause magnetization processes mainly in the ferrite matrix: Bloch walls move and are pinned by the cementite precipitates. The correlation between the microscopic observations and macroscopic magnetic properties of the material is discussed.

Batista, L.; Rabe, U.; Hirsekorn, S.

2013-01-01

244

Microstructure/property relationships in dissimilar welds between duplex stainless steels and carbon steels  

SciTech Connect

The metallurgical characteristics, toughness and corrosion resistance of dissimilar welds between duplex stainless steel Alloy 2205 and carbon steel A36 have been evaluated. Both duplex stainless steel ER2209 and Ni-based Alloy 625 filler metals were used to join this combination using a multipass, gas tungsten arc welding (GTAW) process. Defect-free welds were made with each filler metal. The toughness of both the 625 and 2209 deposits were acceptable, regardless of heat input. A narrow martensitic region with high hardness was observed along the A36/2209 fusion boundary. A similar region was not observed in welds made with the 625 filler metal. The corrosion resistance of the welds made with 2209 filler metal improved with increasing heat input, probably due to higher levels of austenite and reduced chromium nitride precipitation. Welds made with 625 exhibited severe attack in the root pass, while the bulk of the weld was resistant. This investigation has shown that both filler metals can be used to joint carbon steel to duplex stainless steels, but that special precautions may be necessary in corrosive environments.

Barnhouse, E.J. [Weirton Steel Corp., WV (United States); Lippold, J.C. [Ohio State Univ., Columbus, OH (United States)

1998-12-01

245

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

SciTech Connect

Magnetic method has been used to evaluate the volume percentage of {alpha}' 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 {alpha}' 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 {mu}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 {alpha}' martensitic phase in stainless steels.

Zhang Lefu; Takahashi, Seiki; Kamada, Yasuhiro; Kikuchi, Hiroaki; Mumtaz, Khalid; Ara, Katsuyuki; Sato, Masaya [NDE Center, Faculty of Engineering, Iwate University, Morioka, 020-8551 (Japan)

2005-04-09

246

Tribological properties of ion-implanted 52100 steel  

SciTech Connect

Titanium, argon, nitrogen, and iron were implanted in separate strips on a ferritic AISI E52100 cylinder. Three implant energies were chosen to obtain a continuous distribution from the surface to a depth of 120 nm and total doses were 4 x 10/sup 17/ ions cm/sup -2/. The friction coefficient and wear track morphology were measured by sliding against a martensitic AISI 52100 steel ball in air, in a fully formulated lubricant and in highly purified hexadecane. In dry sliding, titanium reduced the friction coefficient to 0.32 and suppressed the near-surface cracking, in agreement with previous work at Harwell and Naval Research Labs. In hexadecane, titanium reduced the friction coefficient to 0.22, iron and nitrogen increased it to 0.7 from 0.55 and all implants decreased wear. In the fully formulated lubricant, only the break-in pattern was modified. Auger measurements showed that carbon penetrated the material with all implants, creating TiC in the Ti implanted strip and presumably strengthening the other implanted areas by carbide precipitates. 10 figures.

Fischer, T.E.; Luton, M.J.; Williams, J.M.; White, C.W.; Appleton, B.R.

1982-01-01

247

Tensile properties and flow behavior analysis of modified 9Cr-1Mo steel clad tube material  

NASA Astrophysics Data System (ADS)

The tensile properties and flow behavior of modified 9Cr-1Mo steel clad tube have been investigated in the framework of various constitutive equations for a wide range of temperatures (300-923 K) and strain rates (3 × 10-3 s-1, 3 × 10-4 s-1 and 3 × 10-5 s-1). The tensile flow behavior of modified 9Cr-1Mo steel clad tube was most accurately described by Voce equation. The variation of instantaneous work hardening rate (? = d?/d?) and ?? with stress (?) indicated two stage behavior characterized by rapid decrease at low stresses (transient stage) followed by a gradual decrease in high stresses (Stage III). The variation of work hardening parameters and work hardening rate in terms of ? vs. ? and ?? vs. ? with temperature exhibited three distinct regimes. Rapid decrease in flow stress and work hardening parameters and rapid shift of ? vs. ? and ?? vs. ? towards low stresses with increase in temperature indicated dynamic recovery at high temperatures. Tensile properties of the material have been best predicted from Voce equation.

Singh, Kanwarjeet; Latha, S.; Nandagopal, M.; Mathew, M. D.; Laha, K.; Jayakumar, T.

2014-11-01

248

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

SciTech Connect

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 over that with a fully austenitic structure lies in the relatively lower alloy content (Cr, Al, Ni, and Mn) in the former, a content that at the same time imparts better casting behavior. The steels studied containing 19-22% have good low-temperature mechanical properties and are therefore suggested for cryogenic purposes.

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

1982-12-01

249

Microstructure and mechanical properties of friction stir processed ODS ferritic steels  

NASA Astrophysics Data System (ADS)

Oxide dispersion strengthened (ODS) steels are considered to be one of the candidate structural materials for advanced blanket systems because of its excellent properties in fusion environments. For more applications of the ODS steels to fusion systems with a huge and complex structure, development of joining technologies is a key issue to be solved. To reserve nano-oxide particles in the matrix homogeneously, the friction stir welding (FSW) is a suitable way to get good welding characteristics as a solid-state processing technique. In this research, effects of friction stir processing (FSP) on microstructure and mechanical properties of a ODS steel were studied to apply FSW process to ODS steels. The microstructure of FSPed ODS steel consists of stirred zone (SZ) and base metal (BM), as reported for other ferritic steels. Although equiaxed grain coarsening occurred through dynamic recrystallization during FSP, the nano-oxide particles in SZ showed fewer change in the size distribution. This resulted that FSP is effective to suppress the anisotropy and minimize the change of nano-oxide particles dispersion morphologies of ODS steel.

Noh, Sanghoon; Kasada, Ryuta; Kimura, Akihiko; Park, Seung Hwan C.; Hirano, Satoshi

2011-10-01

250

The modeling of structure and properties of carburized low-chromium hypereutectoid steels  

NASA Astrophysics Data System (ADS)

Research of carburized high-carbon bearing LH15 (52100) steel is presented. Problems analyzed include thermodynamic and kinetic basis of carburizing in two-phase field (austenite-cementite), carbon content influence in diffusive layer on utilization properties of the examined steel, and functional carbon content influence on chemical and phase composition of carbonized layer. An understanding of these problems enables modeling of functional properties and chemical and phase composition diffusion layers, obtained at definite carburizing parameters. That is the choice of carburizing process parameters (temperature, time, carbon potential) for the best utilizable properties.

Przylecka, M.

1996-04-01

251

Effect of Ti addition on the microstructure and mechanical properties of a cast Fe-Ni-Mo-Mn maraging steel  

NASA Astrophysics Data System (ADS)

To study the effect of Ti on the age hardening behavior of Fe-Ni-Mn maraging steels, a Fe-Ni-Mo-Mn steel was alloyed with Ti then mechanical properties and aging behavior of two cast steels were investigated. In this regard, two heats of nominal compositions of Fe-10Ni-6Mo-3Mn and Fe-lONi-6Mo-3Mn-0. 7Ti were induction melted in air and vacuum respectively and cast in iron mold. After homogenizing at 1473K for 21.6ks and water quenching, solution annealing was performed at 1223K for 3.6ks followed by air cooling. Age hardening behavior at 773Kin the range of 0.36-172. 8 ks was determined. Tensile properties and Charpy impact toughness were measured in the solution annealed and peak-aged conditions. Fractographic features were studied by scanning electron microscope equipped with EDX microanalyses. Tensile properties of the alloys in the peakaged condition were in the range of grade 200 standard maraging steel. It has been found that Ti addition resulted in increasing of hardness and strength in aged condition and decreasing of Charpy impact toughness in both solution annealed and aged conditions. Ti addition also changes type and morphology of inclusions and fracture mechanism from semi-ductile intergranular mode to semi-ductile transgranular one.

Nejad, S. Hossein; Nili Ahmadabadi, M.

2003-10-01

252

HYDROGEN EFFECTS ON THE BURST PROPERTIES OF TYPE 304L STAINLESS STEEL FLAWED VESSELS  

SciTech Connect

The effect of hydrogen on the burst properties Type 304L stainless steel vessels was investigated. The purpose of the study was to compare the burst properties of hydrogen-exposed stainless steel vessels burst with different media: water, helium gas, or deuterium gas. A second purpose of the tests was to provide data for the development of a predictive finite-element model. The burst tests were conducted on hydrogen-exposed and unexposed axially-flawed cylindrical vessels. The results indicate that samples burst pneumatically had lower volume ductility than those tested hydraulically. Deuterium gas tests had slightly lower ductility than helium gas tests. Burst pressures were not affected by burst media. Hydrogen-charged samples had lower volume ductility and slightly higher burst pressures than uncharged samples. Samples burst with deuterium gas fractured by quasi-cleavage near the inside wall. The results of the tests were used to improve a previously developed predictive finite-element model. The results show that predicting burst behavior requires as a material input the effect of hydrogen on the plastic strain to fracture from tensile tests. The burst test model shows that a reduction in the plastic strain to fracture of the material will result in lower volume ductility without a reduction in burst pressure which is in agreement with the burst results.

Morgan, M; Monica Hall, M; Ps Lam, P; Dean Thompson, D

2008-03-27

253

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

254

Microstructure, properties, and failure characteristics of medium-carbon steel subjected to severe plastic deformation  

NASA Astrophysics Data System (ADS)

The paper deals with two-stage processing of medium-carbon steel 45 (0.45 % C; 0.27 % Si; 0.65 % Mn) via quenching and high pressure torsion. Such processing combination allowed producing a nanocomposite microstructure with a ferrite matrix and high-dispersed carbides. The ultimate tensile strength of the nanostructured steel is over 2500 MPa. The processing effect on the structure, mechanical properties and failure mechanisms of steel 45 samples is studied. The peculiarities of static fractures in the samples after HPT are demonstrated in comparison with those after quenching.

Karavaeva, Marina V.; Kiseleva, Svetlana K.; Abramova, Marina M.; Ganeev, Artur V.; Valiev, Ruslan Z.

2014-08-01

255

Experimental and analytical analysis of the high-temperature mechanical properties of steel under continuous casting conditions  

Microsoft Academic Search

The modelling of thermo-mechanical aspects of the continuous casting of steel demands knowledge of the constitutive material equations which describe the complex relationships between stress, strain and time at temperatures up to the melting point. The mechanical properties of steel at higher temperatures depend not only on the composition and temperature of the steel, but also on the microstructure, which,

R. Pierer; C. Bernhard; C. Chimani

256

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

257

Effect of microfissures on fatigue properties of austenitic stainless steel weld metals  

Microsoft Academic Search

High-cycle tension–tension fatigue testing with a 0.1 stress ratio at a frequency of 20 Hz (load control at ambient temperature) was conducted on 316L stainless steel weld metals with and without microfissures. The test results show that microfissures (hot cracking) significantly decrease the fatigue properties in austenitic stainless steel weld metals. The initiation of failure for microfissure-containing samples is linked

Y. Cui; Carl D. Lundin

2005-01-01

258

Effect of process time on structural and tribological properties of ferritic plasma nitrocarburized AISI 4140 steel  

Microsoft Academic Search

AISI 4140 steel was plasma nitrocarburized at a gas mixture of 49%N2+49%H2+2%CO2, for different process times (1, 2, 4, 8 and 12 h), at a temperature of 570 °C. The structural, mechanical and tribological properties of nitrocarburized steel were analyzed using a X-ray diffraction, microhardness tester, scanning electron microscopy, optical microscopy and pin-on-disk tribotester. The results have shown that the

Mehmet Karakan; Akgün Alsaran; Ayhan Çelik

2004-01-01

259

Corrosion properties of active screen plasma nitrided 316 austenitic stainless steel  

Microsoft Academic Search

AISI 316 austenitic stainless steel has been plasma nitrided using the active screen plasma nitriding (ASPN) technique. Corrosion properties of the untreated and AS plasma nitrided 316 steel have been evaluated using various techniques, including qualitative evaluation after etching in 50%HCl+25%HNO3+25%H2O, weight loss measurement after immersion in 10% HCl, and anodic polarisation tests in 3.5% NaCl solution. The results showed

C. X Li; T Bell

2004-01-01

260

Magnetic properties and workability of 6.5% Si steel sheet  

Microsoft Academic Search

NKK led the world in the construction of a continuous production line for manufacturing 6.5% silicon steel sheet in coil form using a CVD siliconizing process. The product is a non-oriented, 6.5 % silicon steel sheet with an iron loss of W1\\/10k = 9.25 W\\/kg (0.1 mm thick) and excellent soft magnetic properties. The workability of this product was improved

H. Haiji; K. Okada; T. Hiratani; M. Abe; M. Ninomiya

1996-01-01

261

Static and impact crack properties of a high-strength steel welded joint  

Microsoft Academic Search

In order to gain the benefits of weldable high-strength steels in pressurized equipment applications, satisfactory toughness and crack properties of the welded joint, both in the weld metal and the heat-affected –zone (HAZ), are required. Experimental investigations of toughness and crack resistance parameters through static and impact tests of a high-strength, low-alloy steel (HSLA) with a nominal yield strength of

M. Zrilic; V. Grabulov; Z. Burzic; M. Arsic; S. Sedmak

2007-01-01

262

Effect of processing parameters on the microstructure and mechanical properties of Al–steel composite foam  

Microsoft Academic Search

Al–steel composite foams comprise of steel hollow spheres embedded in an aluminum matrix and are processed using a gravity\\u000a casting technique. The effect of processing parameters such as casting temperature and cooling rate on the microstructure\\u000a and mechanical behavior was studied to establish structure–property relationships. Results show that the amount and composition\\u000a of intermetallic phases present in the foam microstructure

L. J. Vendra; J. A. Brown; A. Rabiei

2011-01-01

263

Modelling the correlation between processing parameters and properties of maraging steels using artificial neural network  

Microsoft Academic Search

An artificial neural network (ANN) model is developed for the analysis and simulation of the correlation between the properties of maraging steels and composition, processing and working conditions. The input parameters of the model consist of alloy composition, processing parameters (including cold deformation degree, ageing temperature, and ageing time), and working temperature. The outputs of the ANN model include property

Z. Guo; W. Sha

2004-01-01

264

Effect of Autogenous Arc Welding Processes on Tensile and Impact Properties of Ferritic Stainless Steel Joints  

Microsoft Academic Search

The effect of autogeneous arc welding processes on tensile and impact properties of ferritic stainless steel conformed to AISI 409M grade is studied. Rolled plates of 4 mm thickness have been used as the base material for preparing single pass butt welded joints. Tensile and impact properties, microhardness, microstructure, and fracture surface morphology of continuous current gas tungsten arc welding

AK Lakshminarayanan; K Shanmugam; V Balasubramanian

2009-01-01

265

Integrated thermal-microstructure model to predict the property gradients in resistance spot steel welds  

SciTech Connect

An integrated model approach was proposed for relating resistance welding parameters to weldment properties. An existing microstructure model was used to determine the microstructural and property gradients in resistance spot welds of plain carbon steel. The effect of these gradients on the weld integrity was evaluated with finite element analysis. Further modifications to this integrated thermal-microstructure model are discussed.

Babu, S.S.; Riemer, B.W.; Santella, M.L. [Oak Ridge National Lab., TN (United States); Feng, Z. [Edison Welding Inst., Columbus, OH (United States)

1998-11-01

266

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

SciTech Connect

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 related to a change in fracture mode from ductile, dimple to cleavage-like. Finally, although the overaged 17-4 PH casting had a relatively low room temperature Charpy impact energy when compared to wrought 17-4 PH, its fracture toughness was at least comparable to that of wrought 17-4 PH. This observation suggests that prior correlations between Charpy impact energies and fracture toughness, as derived from wrought materials, must be approached with caution when applied to cast alloys.

Rack, H. J.

1981-02-01

267

Biomimetic coupling effect of non-smooth mechanical property and microstructural features on thermal fatigue behavior of medium carbon steel  

Microsoft Academic Search

Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features\\u000a on their body surfaces. Inspired by the coupling phenomenon in biological system, the medium carbon steel specimens with the\\u000a coupling effect of non-smooth mechanical property and microstructural features were fabricated by laser processing. Thermal\\u000a fatigue behavior of specimens with biomimetic coupling

ZhiHui Zhang; LuQuan Ren; Hong Zhou; Xin Tong

2009-01-01

268

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

269

Effect of parameters of the carburized case on the properties of steel 20Kh3MVFA  

Microsoft Academic Search

1.To ensure the highest contact fatigue strength and fatigue limit the carbon concentration in the carburized case on steel 20Kh3MVFA must be higher than for steel 12Kh2N4A-1.3–1.5% as compared with 1.0–1.2%.2.The contact fatigue strength of steel 20Kh3MVFA is ~30% higher than that of steel 12Kh2N4A, which is explained by the larger quantity of carbides and the higher concentration of carbon

A. N. Utkina; Yu. Yu. Cherkis; M. F. Alekseenko

1977-01-01

270

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

2014-08-01

271

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

272

Effect of metallurgical factors on the bulk magnetic properties of non-oriented electrical steels  

NASA Astrophysics Data System (ADS)

Non-oriented electrical steel (NOES) is one of the most common material used in electrical motors. Core loss and permeability are the most important properties that the motor manufacturers look for. Both these properties are structure sensitive and depend on several metallurgical factors; such as chemistry, grain size, crystallographic texture, cleanliness and stress states in non-oriented electrical steels. It has been observed in this course of the study that the grain size and Si content of NOES are the primary controlling factors to core loss, especially at higher frequencies. On the contrary, crystallographic texture plays an important role at lower frequencies. At higher frequency, core loss increases with increasing grain size and decreasing Si content of the steels. Small difference in grain size (~50 ?m) at lower frequency range has little influence on the magnetic properties but has significant adverse effect as frequency reaches high enough.

Ghosh, Pampa; Chromik, Richard R.; Knight, Andrew M.; Wakade, Shekhar G.

2014-04-01

273

Semiconducting properties of passive films formed on stainless steels: Influence of the alloying elements  

Microsoft Academic Search

Passive films formed on stainless steels in a borate buffer solution (pH 9.2) have been investigated by capacitance measurements and photoelectrochemistry. The study was carried out on films formed on AISI type 304 and 316 stainless steels and high purity alloys with differing chromium, nickel, and molybdenum contents. Complementary research by Auger analysis shows that the passive films are composed

N. E. Hakiki; M. D. C. Belo; A. M. P. Simoes; M. G. S. Ferreira

1998-01-01

274

Prediction of Mechanical Properties in Submerged Arc Weld Metal of C–Mn 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

275

Evolution of the mechanical properties and microstructure of ferritic-martensitic steels irradiated in the BOR-60 reactor  

NASA Astrophysics Data System (ADS)

The effect of neutron irradiation on mechanical properties of low-activation ferritic-martensitic (FM) steels 0.1C-9Cr-1W, V, Ta, B and 0.1C-12Cr-2W, V, Ti, B is studied under tension at temperatures of 330-540 °C and doses of 50 dpa. Steel 0.1C-13Cr-Mo, V, Nb, B was chosen for comparison. At irradiation temperatures of 330-340 °C, the radiation hardening of steel with 9%Cr achieves saturation at a dose of 10 dpa. In this case as compared to steels with 12%Cr, the fracture surface is characterized as ductile without cleavage traces. At irradiation temperatures higher than 420 °C, there is no difference in the behavior of the materials under investigation. The data on radiation creep obtained by direct measurement and from the profilometry data satisfy a model ?¯/ ?¯=B 0+D ?, when B0 and D have the values typical for steels of FM type.

Shamardin, V. K.; Golovanov, V. N.; Bulanova, T. M.; Povstyanko, A. V.; Fedoseev, A. E.; Ostrovsky, Z. E.; Goncharenko, Yu. D.

2002-12-01

276

Hydrogen pumping by austenitic stainless steel  

NASA Astrophysics Data System (ADS)

In the present study, hydrogen sorption and desorption kinetics close to equilibrium were investigated in a pinched-off AISI 316 steel cell by a sensitive pressure-rise method. The pressure was monitored with a spinning rotor gauge (SRG) just before the pinch-off and after it for 6 months at two stabilized temperatures: 25 °C and 55 °C. The preprocessing of the cell (of uniform wall thickness 0.15 mm volume 125 cm3, and inner surface 460 cm2) consisted of baking at 200 °C for 109 h with several evacuation cycles to ultrahigh vacuum (UHV). The quantity of released hydrogen during the bake-out procedure equaled the average concentration change ?C=2.8×1017 at. H cm-3. After the pinch-off intentionally done in the high vacuum range where hydrogen represented the residual atmosphere, surprisingly the hydrogen pressure slowly declined from the initial p(328 K)=3.7×10-4 mbar, with an initial rate dp/dt=-5.5×10-11 mbar/s and later attained a stable value, which could be termed the equilibrium. In similar reported experiments, where valving-off began in the UHV, the dp/dt was always positive and constant over several orders of magnitude in pressure. During 6 months of measurements, a sudden temperature jump from 25 °C to 55 °C or back was applied a few times to investigate the stability of the equilibrium or the impact on the pressure course. The most plausible explanation of the results is given along with discussion whether hydrogen permeated through the cell wall or if it was absorbed in the cell wall.

Zajec, Bojan; Nemani?, Vincenc

2005-03-01

277

Magnetic properties of the austenitic stainless steels at cryogenic temperatures  

NASA Astrophysics Data System (ADS)

The magnetization was measured for the austenitic stainless steel of SUS304, SUS304L, SUS316, and SUS316L with the temperature from 5K to 300K and the magnetic field from 0T to 10T. The field dependences of the magnetizations changed at about 0.7T and 4T. The dependence was analyzed with ranges of 0-0.5T, 1-3T, and 5-10T. There was not so much difference between those stainless steels for the usage at small fields and 300 K. The SUS316 and SUS316L samples showed large non-linearity at high fields and 5K. Therefore, SUS304 was recommended for usage at high fields and low temperatures to design superconducting magnets with the linear approximation of the field dependence of magnetization.

Kobayashi, T.; Kobayashi, S.; Itoh, K.; Tsuchiya, K.

2002-05-01

278

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

279

27. STAINLESS STEEL FERMENTING CASKS MADE BY ZERO MANG OF ...  

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

27. STAINLESS STEEL FERMENTING CASKS MADE BY ZERO MANG OF WASHINGTON, MISSOURI. VIEW LOOKING NORTH TOWARD VAULT OF THE TWELVE APOSTLES - Stone Hill Winery, 401 West Twelfth Street, Hermann, Gasconade County, MO

280

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

281

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

282

Influence of Tempering Process on Mechanical Properties of 00Cr13Ni4Mo Supermartensitic Stainless Steel  

Microsoft Academic Search

To investigate the influence of tempering process on microstructural evolutions and mechanical properties of 00Cr13Ni4Mo supermartensitic stainless steel (SMSS), specimens were tempered in the temperature range of 520–720 °C for 3 h followed by air cooling and an optimized tempering temperature was chosen to prolong holding time from 3 to 12 h. After heat treatments, microstructure examination was conducted by

De-ning ZOU; Ying HAN; Wei ZHANG; Xu-dong FANG

2010-01-01

283

Effects of deep cryogenic treatment on static mechanical properties of 18NiCrMo5 carburized steel  

Microsoft Academic Search

In consideration of the raising interest about the application of the deep cryogenic treatment (DCT) on materials, its effects on the static mechanical properties of a commercial gear carburized steel (18NiCrMo5) are investigated through hardness and tensile tests followed by optical fractographic observations. The present study focuses on the comparison between the results given by different sequences of DCT and

Paolo Baldissera; Cristiana Delprete

2009-01-01

284

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

285

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, Özlem; Jones, Peter Tom; Van Balen, Koen; Blanpain, Bart

2013-10-01

286

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

287

Modified stainless steel surfaces targeted to reduce fouling – Evaluation of fouling by milk components  

Microsoft Academic Search

Several stainless steel based surfaces with different properties were evaluated according to their fouling behaviour for different dairy products under different conditions. Surface properties were obtained by the following modification techniques: SiF3+, MoS22+ and TiC ion implantation; diamond-like carbon (DLC) sputtering; DLC, DLC–Si–O and SiOx, plasma enhanced chemical vapor Deposition (PECVD); autocatalytic Ni–P–PTFE and silica coating. Aqueous solutions that simulate

Roxane Rosmaninho; Olga Santos; Tommy Nylander; Marie Paulsson; Morgane Beuf; Thierry Benezech; Stergios Yiantsios; Nikolaos Andritsos; Anastasios Karabelas; Gerhard Rizzo; Hans Müller-Steinhagen; Luis F. Melo

2007-01-01

288

Mechanical and metallurgical properties of ion-nitrided austenitic-stainless steel welds  

NASA Astrophysics Data System (ADS)

Ion nitriding is an operation widely used in industry to harden materials surface. Nowadays, friction welding is one of the special welding methods used for welding the same or different kinds of materials. Especially in industry, it can be necessary to use materials after having operated them with different techniques or to use materials obtained by different manufacturing techniques. Investigating the mechanical and metallurgical properties of this kind of materials can be crucial. In this study, austenitic-stainless steel was used as an experimental material. Additionally, the samples of austenitic stainless steel with a diameter of 10 mm were joined by friction welding. The samples were subjected to ion nitriding process at 550 °C for 24 and 60 h. Then, tensile, fatigue, notch-impact and hardness tests were applied to the weldless and welded parts, and metallographic examinations were carried out. It was found that chromium and iron nitrides precipitated along the grain boundaries and in the middle of the grains. Spectrum patterns revealed that the most dominant phases resulted from the formation of CrN, Fe4N and Fe3N. However, the tests revealed that high temperature and longer time of ion nitriding caused a decrease in the values of fatigue and tensile strengths as well as in the notch-impact toughness in the ion nitrided joints.

Çetinarslan, C. S.; Sahin, M.; Karaman Genç, S.; Sevil, C.

2012-12-01

289

The effect of heat treatment on mechanical properties and corrosion behavior of AISI420 martensitic stainless steel  

Microsoft Academic Search

Martensitic stainless steels are widely used for their good mechanical properties and moderate corrosion resistance. However, the need for superior properties in specific applications (e.g. steam generators, mixer blades, etc.) led to wide researches on the performance improvement of these steels. Heat treatment was recommended as one of the best ways to this regard hence the effects of astenitizing temperature

A. Nasery Isfahany; H. Saghafian; G. Borhani

2011-01-01

290

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 500°C and 700°C 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 700°C 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 500°C ordering steel. The yield strength of the 500°C 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

291

Tensile behavior of functionally graded steels produced by electroslag remelting  

Microsoft Academic Search

Tensile behavior of functionally graded steels produced by electroslag refining has been studied. Functionally graded steels\\u000a containing layers of ferrite, austenite, bainite, and martensite may be fabricatedvia diffusion of alloying elements during electroslag remelting. Tensile strength of the composites depends on the composition\\u000a and number of layers and those have been modeled based on the tensile behavior of individual phases.

J. Aghazadeh Mohandesi; R. Parastar Namin; M. H. Shahosseinie

2006-01-01

292

Transformation characteristics of functionally graded steels produced by electroslag remelting  

Microsoft Academic Search

In this work, functionally graded steel has been produced via diffusion of the alloying elements during electroslag refining. As the alloying element diffuses, it creates alternating\\u000a regions with different transformation characteristics. Thus, it is possible to obtain steel composites with various combinations\\u000a of ferrite, bainite, martensite, and austenite phases. By choosing the appropriate thickness of the slices used to set

J. Aghazadeh Mohandesi; M. H. Shahosseinie

2005-01-01

293

Utilization of steel, pulp and paper industry solid residues in forest soil amendment: Relevant physicochemical properties and heavy metal availability  

Microsoft Academic Search

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, NH2OH·HCl and H2O2+H2O2+CH3COONH4, the BCR method). Produced matrices showed liming effects comparable

Mikko Mäkelä; Gary Watkins; Risto Pöykiö; Hannu Nurmesniemi; Olli Dahl

294

Influence of austenitizing temperature on microstructure and mechanical properties of AISI 431 martensitic stainless steel electron beam welds  

Microsoft Academic Search

The relative effects of various austenitizing temperatures on microstructure and mechanical properties of electron beam welds of AISI 431martensitic stainless steel were studied. The post-weld heat treatments consist of austenitizing the weld samples for 1h at various temperatures, i.e., at 950°C, 1000°C, 1050°C, 1100°C and at 1150°C and air cooling followed by double tempering, i.e., tempering at 670+600°C. In the

A. Rajasekhar; G. Madhusudhan Reddy; T. Mohandas; V. S. R. Murti

2009-01-01

295

The effects of experimental rolling on microstructure and mechanical properties of a Ni-Cu-Cb steel  

Microsoft Academic Search

The effects of hot rolling and warm working on mechanical properties and microstructure of Ni-Cu-Cb steel were investigated.\\u000a In the hot rolled condition optimum strength and toughness resulted from rolling in the upper portion of the austenite plus\\u000a ferrite phase field. This treatment produced a fine-grained structure consisting of equiaxed and acicular ferrite. Unusually\\u000a high strength-toughness combinations were realized by

Edwin Snape

1970-01-01

296

Effect of rare earths on mechanical properties of plasma nitrocarburized surface layer of 17-4PH steel  

Microsoft Academic Search

The aim of this investigation is to reveal the influence of rare earths (RE) addition on mechanical properties of plasma nitrocarburized 17-4PH steel. The nitrocarburized layers were characterized by optical microscope, scanning electron microscope equipped with energy dispersive X-ray analyzer, X-ray diffractometer, microhardness tester and pin-on-disc tribometer. The results showed that RE atoms could diffuse into the surface layer of

Ruiliang LIU; Mufu YAN; Danlei WU

2009-01-01

297

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

298

Magnetic properties of the austenitic stainless steels at cryogenic temperatures  

Microsoft Academic Search

The magnetization was measured for the austenitic stainless steel of SUS304, SUS304L, SUS316, and SUS316L with the temperature from 5K to 300K and the magnetic field from 0T to 10T. The field dependences of the magnetizations changed at about 0.7T and 4T. The dependence was analyzed with ranges of 0-0.5T, 1-3T, and 5-10T. There was not so much difference between

T. Kobayashi; S. Kobayashi; K. Itoh; K. Tsuchiya

2002-01-01

299

Phosphorus removal by electric arc furnace steel slag and serpentinite.  

PubMed

Electric arc furnace (EAF) steel slag and serpentinite were tested in columns either alone or mixed with limestone to determine their capacity to remove phosphorus (P) from a solution containing initially 20mg P/L (for 114 days) than 400mg P/L (for 21 days). EAF steel slag was nearly 100% efficient due to specific P adsorption onto metal hydroxides and precipitation of hydroxyapatite. Serpentinite also showed a good performance that decreased with time, adsorption appearing to be the dominant mechanism for P removal. Mixing limestone with these two materials did not improve their performance and in the case of serpentinite, it actually even decreased it. In 114 days of experimentation, serpentinite alone and the mixture of serpentinite and limestone removed 1.0mg P/g while in 180 days of experimentation, EAF steel slag and the mixture of slag and limestone removed an average of 2.2mg P/g, without attaining their maximum P removal potential. The void hydraulic retention time (HRTv) was a key factor for growing hydroxyapatite crystals and had a significant effect on P removal efficiency by EAF steel slag. A temporary increase in HRTv caused by clogging resulted in an increase in EAF steel slag efficiency (from 80% to almost 100%) towards the end of investigation. Results from this study indicate that the use of EAF steel slag in constructed wetlands or filter beds is a promising solution for P removal via adsorption and precipitation mechanisms. PMID:16564560

Drizo, Aleksandra; Forget, Christiane; Chapuis, Robert P; Comeau, Yves

2006-05-01

300

Corrosion inhibition of stainless steel by a sulfate-reducing bacteria biofilm in seawater  

NASA Astrophysics Data System (ADS)

Corrosion inhibition of stainless steel due to a sulfate-reducing bacteria (SRB) biofilm in seawater was studied. By atomic force microscopy, a layer of fish-scale-like biofilm was found to form as stainless steel coupons were exposed to the culture media with SRB, and this biofilm grew more and more compact. As a result, coupons' surface under the biofilm turned irregular less slowly than that exposed to the sterilized culture media. Then, physicoelectric characteristics of the electrode/biofilm/solution interface were investigated by electrochemical impedance spectroscopy (EIS), and the coverage of the biofilm as well as the relative irregularity of coupons' surface was also recorded by EIS spectra. Finally, anodic cyclic polarization results further demonstrated the protective property of the biofilm. Therefore, in estimation of SRB-implicated corrosion of stainless steel, not only the detrimental SRB metabolites but also the protective SRB biofilm as well should be taken into account.

Li, Fu-shao; An, Mao-zhong; Duan, Dong-xia

2012-08-01

301

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

302

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

303

A novel method of modeling 2D magnetic properties of electrical steel sheet in electromagnetic devices  

Microsoft Academic Search

This paper presents a material modeling method of silicon steel sheet considering harmonic magnetic field in the model. A new experiment method that can provide magnetic property data of high-order harmonic magnetic field is introduced. A material modeling method associated with the measurement data is provided. A novel time periodic iterative method of finite element analysis (FEA) is proposed to

Xiaoyan Wang; Dexin Xie; W. N. Fu

2010-01-01

304

The microstructural, mechanical, and fracture properties of austenitic stainless steel alloyed with gallium  

Microsoft Academic Search

The mechanical and fracture properties of austenitic stainless steels (SSs) alloyed with gallium require assessment in order to determine the likelihood of premature storage-container failure following Ga uptake. AISI 304 L SS was cast with 1, 3, 6, 9, and 12 wt pct Ga. Increased Ga concentration promoted duplex microstructure formation with the ferritic phase having a nearly identical composition

D. G. Kolman; J. F. Bingert; R. D. Field

2004-01-01

305

An Evaluation of the Properties of Double Melted 18 Percent Ni CO Mo Maraging Steel.  

National Technical Information Service (NTIS)

The evaluation of the 18% Ni-Co-Mo maraging steel has demonstrated that provided double vacuum melted stock is used the material possesses excellent static mechanical properties as either bar or forgings. The maintenance of high notched strength and good ...

A. E. Longley

1972-01-01

306

Two-dimensional magnetic properties of silicon steel sheet subjected to a rotating field  

Microsoft Academic Search

A study of the two-dimensional rotational magnetic properties of a steel sheet are discussed. These are measured making use of the vector relation between magnetic field strength H and magnetic flux density B. The results of this study lead to the following main conclusions: the permeability tensor becomes a full matrix under rotating flux; the off-diagonal terms of the permeability

Masato Enokizono; Takashi Todaka; Shinichi Kanao; Johannes Sievert

1993-01-01

307

Mechanical properties of hot isostatic pressed type 316LN steel after irradiation  

Microsoft Academic Search

Hot isostatic pressing (HIPing) of powder is considered as a tentative manufacturing method for primary wall components of thermonuclear reactors. In the present work some mechanical properties of specimens from HIPed powder as well as from wrought, reference type 316 LN international thermonuclear experimental reactor (ITER) grade steel have been compared. Tensile, low cycle fatigue and fracture toughness tests were

A. Lind; U. Bergenlid

2000-01-01

308

Effect of residual stresses on individual phase mechanical properties of austeno-ferritic duplex stainless steel  

Microsoft Academic Search

The mechanical properties of both phases in duplex stainless steel have been studied in situ using neutron diffraction during mechanical loading. Important differences in the evolution of lattice strains are observed between tests carried out in tension and compression. An elastoplastic self-consistent model is used to predict the evolution of internal stresses during loading and to identify critical resolved shear

R. Dakhlaoui; A. Baczma?ski; C. Braham; S. Wro?ski; K. Wierzbanowski; E. C. Oliver

2006-01-01

309

Effect of cryogenic treatment on the mechanical properties of 4340 steel  

Microsoft Academic Search

This experimental study investigated the effects of cryogenic treatment on the mechanical properties and microstructures of AISI 4340 steel. Mechanical tests, including rotating fatigue, impact and hardness were carried out, after various heat treating conditions and the results were compared. Fracture features of specimens were also compared. It was shown that in general, hardness and fatigue strength of the cryogenically

S. Zhirafar; A. Rezaeian; M. Pugh

2007-01-01

310

Influence of carbon, manganese and nickel on microstructure and properties of strong steel  

E-print Network

tungsten arc welding and tightly controlled conditions it proved possible to produce weld metals with both procedure. Shielded metal arc welding (SMAW), flux cored arc welding, and submerged arc welding offerInfluence of carbon, manganese and nickel on microstructure and properties of strong steel weld

Cambridge, University of

311

Enhanced Mechanical Properties of a Hot-Stamped Advanced High-Strength Steel via Tempering Treatment  

NASA Astrophysics Data System (ADS)

The hot stamping process has an extensive range of applications due to its advantages over the traditionally used stamping techniques developed in the past. To enhance the mechanical properties of the indirectly hot-stamped parts, the quenching and partitioning (Q&P) process has been recently applied on boron-alloyed steel. In the current research, it was observed that the tempering treatment on the directly hot-stamped boron steel resulted in better mechanical properties and higher formability index compared with the reported results using the Q&P process. The nano-carbide formation and the dislocation annihilation during the tempering treatment were suggested as the evident reasons for the occurrence of the mentioned robust properties. The ease of the practical implementation of the tempering route together with the markedly enhanced mechanical properties of the tempered parts make the suggested method privileged. Additionally, the variations in the yield strength before and after tempering were quantitatively evaluated.

Naderi, M.; Abbasi, M.; Saeed-Akbari, A.

2013-04-01

312

Steel castings by the electroslag casting technique  

NASA Astrophysics Data System (ADS)

Electroslag casting facilities in Canada and the United States were reviewed. Several value body castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and 18% Cr-8% Ni (Mo) steels were made at the University of British Columbia facility. These castings were examined for surface finish, chemical segregation, and macrostructure in the as-cast condition and after various heat treatments. Castings were subjected to tensile, charpy impact, and creep testing. Results of these tests were compared with similar data on wrought material and where applicable, with data on sand castings.

Sikka, V. K.; Mitchell, A.

1984-10-01

313

Steel castings by the electroslag casting technique  

SciTech Connect

Electroslag casting facilities in Canada and the United States were reviewed. Several valve body castings of 2 1/4 Cr-1 Mo, 9 Cr-1 Mo, and 18% Cr-8% Ni(Mo) steels were made at the University of British Columbia facility. These castings were examined for surface finish, chemical segregation, and macrostructure in the as-cast condition and after various heat treatments. Castings were subjected to tensile, Charpy impact, and creep testing. Results of these tests were compared with similar data on wrought material and, where applicable, with data on sand castings. 22 figures.

Sikka, V.K.; Mitchell, A.

1984-10-01

314

Fracture toughness and tensile properties of nano-structured ferritic steel 12YWT  

NASA Astrophysics Data System (ADS)

The oxide dispersion strengthened (ODS) steels are being developed and investigated for fission and fusion structural applications in Japan, Europe, and the United States. In this paper, the fracture toughness and tensile properties of an ODS steel with nominal composition Fe-12Cr-2.5W-0.4Ti-0.25Y 2O 3 (designated 12YWT) were investigated and compared to commercial reduced-activation ferritic/martensitic (RAFM) steels. Small, 1.6-mm thick and 3.2-mm wide, 3-point bend specimens were used for fracture toughness characterization of this steel. Specimens were fatigue pre-cracked to initial crack length ( a) to width ( W) ratio of 0.45 and tested quasi-statically in the temperature range from -50 °C to 550 °C. Specimens tested up to 50 °C exhibited elastic-plastic cleavage fracture that was typical for the transition region in ferritic steels. The master curve transition temperature, T0, for the 12YWT alloy was determined to be 102 °C. Specimens tested at 100 °C and higher exhibited ductile stable crack growth. In these cases, the J-integral at the onset of stable crack growth ( JIc) was determined from the J- R curves. Their equivalent values in terms of stress intensity factor, K, were about 93 MPa?m at 100 °C and decreased to 53 MPa?m at 550 °C. This study showed that oxide dispersion strengthening resulted in significant decreases in the toughness properties compared to commercial RAFM steels, although appreciable level of toughness was still retained. Tensile tests were performed at temperatures between room temperature and 800 °C. As expected, this material exhibited very high yield strength, ˜1300 MPa, at room temperature. For comparison, the yield strength of commercial RAFM steels is about 550 MPa. Yield strength of 12YWT decreases as test temperature increases and at 800 °C it is about 323 MPa.

Sokolov, M. A.; Hoelzer, D. T.; Stoller, R. E.; McClintock, D. A.

2007-08-01

315

THE MANUFACTURING PROPERTIES OF GALVANISED STEEL SHEET WITH HEXAGONAL AND TETRAGONAL NETWORK OF CIRCLE HOLES  

Microsoft Academic Search

Galvanized steel sheet of 0.8 mm in thickness was drilled with circle holes of 2.5 mm diameter and spacing arranged in tetragonal and hexagonal pattern. The manufacturing properties of specimen were studied through drawing and stretching simulative test. It was concluded from the results that, at high ratio of punch to hole diameter (40\\/2.5), the drawing properties (LDR) of both

Rahmat Saptono

316

Relationship between ultrasonic characteristics and mechanical properties of tempered martensitic stainless steel  

Microsoft Academic Search

This research studied the relationship between the ultrasonic characteristics and the mechanical properties of tempered CA-15\\u000a martensitic stainless steel (MSS). The results show that, for as-quenched specimens, a chromium carbide film at the martensitic\\u000a boundary of the as-cast specimen will disappear causing a change in the mechanical properties (e.g., the tensile strength\\u000a is decreased or the hardness and the toughness

Cheng-Hsun Hsu; Hwei-Yuan Teng; Yeong-Jern Chen

2004-01-01

317

Determination of lüders strains and flow properties in steels from hardness\\/microhardness tests  

Microsoft Academic Search

Development of radiation tolerant materials for use in fusion reactors requires testing of small volumes of candidate materials\\u000a in high energy neutron irradiation facilities. As part of an effort to develop methods for extracting mechanical property\\u000a information from small specimens, this study investigated techniques to characterize flow properties of steels exhibiting\\u000a Lders strains from ball indentation hardness\\/microhardness tests. A quantitative

Fahm Y M. Haggag; Glenn E. Lucas

1983-01-01

318

Effect of inoculation on the properties of 7Kh2SMF roller steel  

SciTech Connect

The effect of electrochemical inoculation of 7Kh2SMF steel by rare earth and rare metals during electroslag remelting was studied. The remelting was done in a crystallizer under flux with additions of rare earth metal oxides of the cerium group and rare metals such as niobium, tantalum, and zirconium. Steel inclusions were measured by an ocular rule and divided according to their composition into oxides, sulfides, oxysulfides, and nitrides. The inoculation of rare earth and rare metals caused a change in the type of carbon distribution in steel, reduced oxide and nonmetallic inclusions, and smoothed the structure over the ingot cross section.

Kiselev, V.I.; Zvigintseva, G.E.; Nikolaeva, N.L.

1988-03-01

319

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

320

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

321

Effect of cryogenic deformation on the structure and properties of chromium-nickel steels  

NASA Astrophysics Data System (ADS)

The effect of rolling at a temperature of 77 K and subsequent tempering on the structure and properties of chromium-nickel 05Kh14N14T2 and 15Kh14N14Yu1 steels is investigated. The formation of a nanocrystalline martensite phase in an austenitic matrix has been established. It is shown that additional hardening of the metal occurs due to the precipitation of intermetallic phases during heat treatment. The steels under study are high-strength and hard-magnetic after cryogenic deformation and heat treatment.

Glezer, A. M.; Rusanenko, V. V.; Zhukov, O. P.; Libman, M. A.; Klippenshtein, A. D.

2012-10-01

322

Thermal and mechanical properties of the Cr-Mn-(Ni-free) austenitic steels for fusion reactor applications  

NASA Astrophysics Data System (ADS)

Measurements up to 500°C of selected thermal and mechanical properties (density, thermal conductivity, thermal expansion, Young's modulus, Poisson's ratio, and ultimate tensile strength) are reported for four Cr-Mn (Ni-free) austenitic steels of interest for fusion reactor design and of the European AISI 316 L reference fusion material. The results are discussed in terms of the impact of these properties on the lifetime of fusion reactor components by calculating the thermal stress factor. Other important effects such as radiation, sputtering and plasma disruption damage, have also been taken into consideration on the basis of preliminary experience.

Piatti, G.; Schiller, P.

1986-11-01

323

Formation of Wear Resistant Steel Surfaces by Plasma Immersion Ion Implantation  

SciTech Connect

Plasma immersion ion implantation (PIII) is a versatile and fast method for implanting energetic ions into large and complex shaped three-dimensional objects where the ions are accelerated by applying negative high voltage pulses to a substrate immersed in a plasma. As the line-of-sight restrictions of conventional implanters are circumvented, it results in a fast and cost-effective technology. Implantation of nitrogen at 30 - 40 keV at moderate temperatures of 200 - 400 deg. C into steel circumvents the diminishing thermal nitrogen activation encountered, e.g., in plasma nitriding in this temperature regime, thus enabling nitriding of additional steel grades. Nitride formation and improvement of the mechanical properties after PIII are presented for several steel grades, including AISI 316Ti (food industry), AISI D2 (used for bending tools) and AISI 1095 (with applications in the textile industry)

Maendl, S.; Rauschenbach, B. [Institute fuer Oberflaechenmodifizierung, 04303 Leipzig (Germany)

2003-08-26

324

Diffusion of Aluminum Into Steel Substrates By Means Of Hot Dip Aluminizing  

SciTech Connect

Surface coating is an efficient and economical method to obtain desirable material surfaces properties. As compared to other coating techniques, hot dip coating can be considered as the most economical way to protect steel surfaces. Hot dip aluminizing technique was investigated in this study. Experiments have been conducted on the mild steel substrates with 10 mm diameter. The substrates were dipped into the molten aluminum maintained at temperature 750 deg. C for 5, 10, 15, 20, 25 and 30 minutes. Optical microscopy, scanning electron microscope and energy dispersive X-ray spectroscopy were used in this investigation. From the microstructure observation, it showed the appearance of intermetallic layer covered by the top layer of Al on the mild steel substrate increased with the increase in dipping time. The result of EDX analysis revealed the existence of Fe and Al in form of new Al-Fe phase. This indicated the possible formation of the intermetallic layers.

Husain, Hishamuddin Hj.; Razak Daud, Abdul [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Daud, Muhamad [Malaysian Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia)

2010-01-05

325

Residual stresses and microstructure of H13 steel formed by combining two different direct fabrication methods  

SciTech Connect

Direct fabrication (DF) of tool and die steels by rapid solidification techniques can produce near-net-shape parts and components with unique properties, and without the distortions caused by conventional normalizing and tempering heat-treatments. When combined with sophisticated 3-dimensional computer control to build complex solid metallic shapes, one has the capability of using DF for rapid prototyping. Spray forming using a circular converging/diverging atomizer is a DF process being developed at the Idaho National Engineering and Environmental Laboratory (INEEL) for rapid manufacturing of tool and die steels like H-13. Laser Engineered Net Shaping (LENS{trademark}) is a DF process being developed at Sandia National laboratory (SNL). LENS involves laser-processing fine powder metal sprays into complex, fully-dense 3-dimensional shapes with fine-detail control that would allow rapid prototyping of tools or dies. One logical combination of the two processes is to combine spray forming to replicate most of the die surface and backing, and then t o build other die-surface fine-features with LENS. Premium H-13 steel was used because it belongs to the widely used group of hot-work steels that have good resistance to heat, pressure and abrasion for metal-forging and aluminum die-casting applications. The microstructure and residual stresses that exist across the interface of a composite metal produced by these two DF methods are critical parameters in producing crack-free components with functional properties. The purpose of this work is to combine unique neutron-diffraction facilities at the Oak Ridge National Laboratory (ORNL) for measuring bulk residual stresses with these two different DF processes to characterize LENS deposits of H-13 steel made on a spray-formed base of that same steel.

Maziasz, P.J.; Payzant, E.A.; Schlienger, M.E.; McHugh, K.M.

1998-10-13

326

Influence of alloy elements on the properties of manganese steel in the 293-4 K temperature range  

SciTech Connect

Austenitic manganese steels are primarily used as substitutes for expensive chrome-nickel steels. Recently, they have been used for various parts, particularly in cryogenic turbine manufacture where rigid requirements are imposed on the magnetic permeability of the materials used. It is known that Fe-C-Mn steels have unique magnetic properties. For example, the magnetic permeability of these steels is not only significantly less than that of chromenickel ones, in contrast to them it is practically independent of temperature in the 293-4/sup 0/K range -- the result of the unordered magnetic structure of Fe-C-Mn steels and the complex magnetic transformations occurring in them in cooling. This paper presents the results of an investigation of the mechanical properties of FeC-Mn steels additionally alloyed with chromium and aluminum at various temperatures.

Ermakov, E.S.; Khoroshailov, V.G.

1985-09-01

327

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

328

Irradiation Induced Defect Characterization in Reactor Pressure Vessel Steel by Small Angle Neutron Scattering  

NASA Astrophysics Data System (ADS)

The degradation of the mechanical properties of the RPV (Reactor Pressure Vessel) steel during an irradiation in a nuclear power plant is closely related to the irradiation induced defects. The size of these defects is known to be a few nanometer, and the small angle neutron scattering technique is regarded as the best non destructive technique to characterize the nano sized inhomogeneities in bulk samples. The investigated the RPV steel has been used in YeongKwang nuclear power plant at Korea and the Cu content of the RPV steel is 0.06 wt%. The RPV steel was irradiated in the HANARO reactor at KAERI. The small angle neutron scattering experiments were performed by the SANS instrument in the HANARO reactor. The nano sized irradiation induced defects were quantitatively analyzed by SANS and the type of the irradiation induced defects was discussed in detail. The relation between irradiation induced defects and the yield strength was investigated. The characteristics of irradiation induced defects in low Cu containing RPV steel were discussed.

Han, Yougn-Soo; Shin, Eun-Joo; Lee, Chang-Hee; Park, Duck-Gun

329

Rapid reduction of Staphylococcus aureus populations on stainless steel surfaces by zeolite ceramic coatings containing silver and zinc ions  

Microsoft Academic Search

This study demonstrates the anti- Staphylococcus aureus properties of stainless steel surfaces coated with zeolite containing 2.5% silver and 14% zinc ions. Stainless steel panels with and without the heavy-metal-containing coatings were inoculated with S. aureus and incubated at room temperature. Survival of S. aureus was significantly reduced by the silver\\/zinc coatings within 1h. Many hospital surfaces could be constructed

K. R. Bright; C. P. Gerba; P. A. Rusin

2002-01-01

330

Effect of strain rate and temperature on the tensile properties of MANET II steel  

SciTech Connect

MANET II, a modified 12% Cr steel with the German designation DIN 1.4914, is a candidate structural material for the first wall and blanket in fusion reactors. In the present study, the tensile properties of this steel were investigated in the temperature range of 25 to 350 C at strain rates of 5 {times} 10{sup {minus}5}, 1.2 {times} 10{sup {minus}4}, and 1.2 {times} 10{sup {minus}3}s{sup {minus}1}. Both microstructure and fracture surfaces were examined using optical and scanning electron microscopic (SEM) techniques. The results showed that the steel suffers dynamic strain aging, although no serrated flow was observed. Yield strength, ultimate strength, and elongation showed negative strain rate sensitivity. Dynamic strain aging also affected the strain hardening rate. Results are discussed with regard to the chemical composition and fracture surface morphology.

Ghoneim, M.M. [Atomic Energy Authority, Cairo (Egypt)

1997-08-01

331

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

332

Effect of admixtures on mechanical properties of steel-fibre-reinforced polymer high-strength concrete  

NASA Astrophysics Data System (ADS)

In this study, a new kind of steel fibre reinforced polymer high-strength concrete was developed for bridge structures. This material is component of C60 concrete and some admixtures, including steel fibre, polymer latex, fly ash, etc. An experimental study was performed to determine the mixture ratio of the new material and test the fundamental mechanical performances, such as the tensile and compressive strength. Scanning electron microscope (SEM) investigation and mechanism analysis were employed to study the effect of the admixtures on the material properties. The results show that the strength, toughness and crack resistance of the C60 concrete are improved if appropriate content of steel fibre, polymer latex and fly ash are added.

Huang, Pei-yan; Zheng, Shun-chao; Guo, Wenying; Deng, Jun

2008-11-01

333

A SUMMARY OF COMPARATIVE PROPERTIES OF AIR-MELTED AND VACUUM-MELTED STEELS AND SUPER-ALLOYS  

Microsoft Academic Search

A compilation of comparative properties of air-melted and vacuum-melted ; steels and superalloys is presented. The data revealed that: The reduction in ; hydrogen content of large heats of low-alloy steels effected through vacuum ; pouring can lead to improved ductility. A reduction in gas, inclusion, and ; impurity content of low-alloy or chroraium hot-work die steels thrt result from

D. C. Ludwigson; F. R. Morral

1960-01-01

334

Microstructure and Mechanical Properties of 0.63C-12.7Cr Martensitic Stainless Steel during Various Tempering Treatments  

Microsoft Academic Search

In this study, the microstructure and mechanical properties of 0.63C-12.7Cr martensitic stainless steel during various tempering treatments were investigated. Experimental results demonstrate that finely distributed primary carbides can be observed in 0.63C-12.7Cr martensitic stainless steel. It was also found that the measured hardness of 0.63C-12.7Cr martensitic stainless steel after 300°C tempered treatment for 60 minutes can still reach to 677Hv.

Yuli Lin; Chih-Chung Lin; Tsung-Hsien Tsai; Hong-Jen Lai

2010-01-01

335

The Influence of Corrosion and Cross-Section Diameter on the Mechanical Properties of B500 c Steel  

Microsoft Academic Search

Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical\\u000a properties of steel rebar. Exposure to chloride, seawater, salt and saltwater and deicing chemical environments influences\\u000a the concrete-steel bond and weakens it. A considerable strength factor of the two-phase steel B500c (martensitic, ferritic-perlitic) is considered to be the outer martensitic cortex

Ch. Alk. Apostolopoulos

2009-01-01

336

The Influence of Corrosion and Cross-Section Diameter on the Mechanical Properties of B500c Steel  

Microsoft Academic Search

Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical properties of steel rebar. Exposure to chloride, seawater, salt and saltwater and deicing chemical environments influences the concrete-steel bond and weakens it. A considerable strength factor of the two-phase steel B500c (martensitic, ferritic-perlitic) is considered to be the outer martensitic cortex

Ch. Alk. Apostolopoulos

2009-01-01

337

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

338

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

339

Mechanical and Thermal Properties of Ultra-High Carbon Steel Containing Aluminum  

SciTech Connect

The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is shown that this change is a function of the atomic percent of solute and of the valence state when comparisons are made with UHCSs containing silicon and tin as solutes. The thermal expansion of UHCSs with dilute aluminum additions shows no discontinuity in the vicinity of the ferrite-austenite transformation temperature. This is the result of a three phase region of ferrite, carbides and austenite. The slope of the expansion curve is higher in the austenite range than in the ferrite range as a result of the dissolution of carbon in austenite with temperature. Processing to achieve a fine grain size in UHCS-Al alloys was principally by hot and warm working (HWW) followed by isothermal warm working (IWW). The high temperature mechanical properties of a UHCS-10Al-1.5C material show nearly Newtonian-viscous behavior at 900 to 1000 C. Tensile elongations of 1200% without failure were achieved in the 1.5%C material. The high oxidation corrosion resistance of the UHCS-10Al materials is described.

Syn, C K; Lesuer, D R; Goldberg, A; Tsai, H C; Sherby, O D

2005-10-03

340

Mechanical and Thermal Properties of Ultra-High Carbon Steel Containing Aluminum  

SciTech Connect

The properties of ultrahigh carbon steels (UHCS) are strongly influenced by aluminum additions. Hardness studies of quenched UHCS-Al alloys reveal that the temperature for the start of transformation increases with increases in aluminum content. It is shown that this change is a function of the atomic percent of solute and of the valence state when comparisons are made with UHCSs containing silicon and tin as solutes. The thermal expansion of UHCSs with dilute aluminum additions shows no discontinuity in the vicinity of the ferrite-austenite transformation temperature. This is the result of a three phase region of ferrite, carbides and austenite. The slope of the expansion curve is higher in the austenite range than in the ferrite range as a result of the dissolution of carbon in austenite with temperature. Processing to achieve a fine grain size in UHCS-Al alloys was principally by hot and warm working (HWW) followed by isothermal warm working (IWW). The high temperature mechanical properties of a UHCS-10Al-1.5C material show nearly Newtonian-viscous behavior at 900 to 1000 C. Tensile elongations of 1200% without failure were achieved in the 1.5%C material. The high oxidation corrosion resistance of the UHCS-10Al materials is described.

Syn, C K; Lesuer, D R; Goldberg, A; Tsai, H; Sherby, O D

2006-01-31

341

Effect of Annealing Temperature on Microstructure and Mechanical Properties of Bulk 316L Stainless Steel with Nano- and Micro-crystalline Dual Phases  

NASA Astrophysics Data System (ADS)

Microstructures and mechanical properties of 316L stainless steels with dual phases austenite prepared by an aluminothermic reaction casting were explored. It is found that the steels consist of nano- and micro-crystalline austenite phases, a little ? ferrite and contaminations. Before and after annealing at 1073 K and 1273 K (800 °C and 1000 °C), average grain sizes of the nanocrystalline austenite phase are about 32, 31, 38 nm, respectively. Tensile strength increases first from 371 to 640 MPa and then decreases to 454 MPa. However, elongation ratio increases gradually from 16 to 23 and then 31 pct after annealing. The results illustrate that the steel after annealing at 1073 K (800 °C) has better properties, also indicating that combination of dual nano- and micro-crystalline austenite phase is conductive to improving tensile properties of materials.

La, Peiqing; Wei, Fuan; Lu, Xuefeng; Chu, Chenggang; Wei, Yupeng; Wang, Hongding

2014-10-01

342

Tensile and Charpy impact properties of irradiated reduced-activation ferritic steels  

SciTech Connect

Tensile tests were conducted on 8 reduced-activation Cr-W steels after irradiation to 15-17 and 26-29 dpa, and Charpy impact tests were conducted on steels irradiated to 26-29 dpa. Irradiation was in Fast Flux Test Facility at 365 C on steels containing 2.25-12% Cr, varying amounts of W, V, and Ta, and 0.1%C. Previously, tensile specimens were irradiated to 6-8 dpa and Charpy specimens to 6-8, 15- 17, and 20-24 dpa. Tensile and Charpy specimens were also thermally aged to 20,000 h at 365 C. Thermal aging had little effect on tensile properties or ductile-brittle transition temperature (DBTT), but several steels showed a slight increase in upper-shelf energy (USE). After 7 dpa, strength increased (hardened) and then remained relatively unchanged through 26-29 dpa (ie, strength saturated with fluence). Post-irradiation Charpy impact tests after 26-29 dpa showed that the loss of impact toughness (increased DBTT, decreased USE) remained relatively unchanged from the values after 20-24 dpa, which had been relatively unchanged from the earlier irradiations. As before, the two 9Cr steels had the most irradiation resistance.

Klueh, R.L.; Alexander, D.J.

1996-10-01

343

Long-term aging of cast stainless steels: Mechanisms and resulting properties  

SciTech Connect

Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320, and 290/sup 0/C. The results indicate that thermal aging increases the tensile strength and decreases the impactenergy, J/sub IC/ and tearing modulus of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The low-carbon CF-3 steels were the most resistant and the molybdenum-containing high-carbon CF-8M steels were the most susceptible to low-temperature embrittlement. The influence of nitrogen content and distribution of ferrite on loss of toughness are discussed. Data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280 to 450/sup 0/C, i.e., extrapolation of high-temperature data to reactor temperatures may not be valid for some compositions of cast stainless steels. 13 refs., 13 figs., 2 tabs.

Chopra, O.K.; Chung, H.M.

1987-09-01

344

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

2014-08-01

345

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

346

Nanoscale Precipitation in a Maraging Steel Studied by APFIM  

NASA Astrophysics Data System (ADS)

This article summarizes findings from our previous investigations and recent studies concerning precipitation in a maraging steel of type 13Cr-9Ni-2Mo-2Cu (at.%) with small additions of Ti (1 at.%) and Al (0.7 at.%). The material was investigated after aging at 475°C up to 400 h using both conventional and three-dimensional atom-probe analyses. The process of phase decomposition in the steel proved to be complicated. It consisted of precipitation of several phases with different chemistry. A Cu-rich phase was first to precipitate and Mo was last in the precipitation sequence. The influence of the complex precipitation path on the material properties is discussed. The investigation clearly demonstrated the usefulness of the applied techniques for investigation of nanoscale precipitation. It is also shown that, complementary methods (such as TEM and EFTEM) giving structural and chemical information on a larger scale must be applied to explain the good properties of the steel after prolonged aging.

Stiller, Krystyna; Hättestrand, Mats

2004-06-01

347

Microstructural evolution of Y 2O 3 and MgAl 2O 4 ODS EUROFER steels during their elaboration by mechanical milling and hot isostatic pressing  

Microsoft Academic Search

Different ODS EUROFER steels reinforced with Y2O3 and MgAl2O4 were elaborated by mechanical milling and hot isostatic pressing. Good compromise between strength and ductility could be obtained but the impact properties remain low (especially for the Y2O3 ODS steel). The materials were structurally characterized at each step of the elaboration. During milling, the martensite laths of the steel are transformed

C. Cayron; E. Rath; I. Chu; S. Launois

2004-01-01

348

Microstructure-Property Relationship in the Thermomechanically Processed C-Mn-Si-Nb-Al-(Mo) TRIP Steels before and after PS/BH Treatment  

SciTech Connect

The effect of prestraining and bake hardening (PS/BH) on the development of microstructures and mechanical properties in thermomechanically processed transformation-induced plasticity (TRIP) steels with additions of Nb, Mo, and Al was studied by atom probe tomography (APT) and transmission electron microscopy (TEM). An increase in number density and sizes of clusters and nanoscale precipitates was observed in both steels but was more significant in the Nb-Al-Mo steel than in the Nb-Al steel. This increase could be explained by the possible fast diffusion of Nb and Mo atoms at low temperatures, as was observed for surface diffusivity. The contributions of cluster strengthening and precipitation strengthening to the yield strength increment after PS/BH were estimated.

Timokhina, I. B. [Monash University, Australia; Enomoto, M [Ibaraki University, Japan; Miller, Michael K [ORNL; Pereloma, E. V. [University of Wollongong, Wollongong, Australia

2012-01-01

349

Effect of vacuum arc and electroslag remelting on the anisotropy of the properties of structural steels  

Microsoft Academic Search

o 1.Melting steel by the ESR and VAR methods, and combination of the two, substantially increases the plasticity and ductility of structural steels 18Kh2N4VA, 40KhNMA, and 35Kh2GSMA both in the longitudinal and, particularly, the transverse directions. 2.ESR and VAR substantially reduce the coefficient of anisotropy of the impact toughness and the specific reduction in section. The higher the anisotropy of

M. B. Balakhovskaya; Ya. E. Gol'dshtein; E. S. Zel'dovich; V. G. Kapel'nitskii

1968-01-01

350

Corrosion protection of mild steel by electroactive polyaniline coatings  

Microsoft Academic Search

The ability of polyaniline (PANi) to act as a protective coating for mild steel corrosion in saline and acid was investigated by electrochemical impedance spectroscopy. The impedance behaviour is best explained by a mediated redox reaction in which PANi passivates the metal surface and reoxidizes itself by dissolved oxygen. The effectiveness of such a process, which also provides the repassivation

P Li; T. C Tan; J. Y Lee

1997-01-01

351

Effect of Reverse Austenite on the Cryogenic Tensile Properties of 0Cr13Ni4Mo Martensitic Steel  

NASA Astrophysics Data System (ADS)

Reverse austenite and its effect on the cryogenic tensile properties in the temperature range of 20 °C to -196 °C in 0Cr13Ni4Mo steel were investigated by electron microscopy, X-ray diffraction and tensile tests. Different amounts of reverse austenite were obtained by controlling tempering temperatures. It was revealed that good cryogenic ductility of the steel was obtained due to the existence of reverse austenite and its transformation to martensite during deformation. However, cryogenic ductilities were found to be related to the amounts of transformable reverse austenite during deformation rather than to the total amounts of all reverse austenite in the samples. The maximums of the ductility of the specimens containing reverse austenite were found at 0 °C or at -50 °C.

Li, X. Y.; Song, Y. Y.; Li, Y. Y.

2008-03-01

352

Perfluorocarbon thin films and polymer brushes on stainless steel 316L for control of interfacial properties  

PubMed Central

Perfluorocarbon thin films and polymer brushes were formed on stainless steel 316L (SS316L) to control the surface properties of the metal oxide. Substrates modified with the films were characterized using diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), contact angle analysis, atomic force microscopy (AFM), and cyclic voltammetry (CV). Perfluorooctadecanoic acid (PFOA) was used to form thin films by self-assembly on the surface of SS316L. Polypentafluorostyrene (PFS) polymer brushes were formed by surface initiated polymerization using SAMs of 16-phosphonohexadecanoic acid (COOH-PA) as the base. PFOA and PFS were effective in significantly reducing the surface energy and thus the interfacial wetting properties of SS316L. The SS316L control exhibited a surface energy of 38 mN/m compared to PFOA and PFS modifications, which had surface energies of 22 and 24 mN/m, respectively. PFOA thin films were more effective in reducing the surface energy of the SS316L compared to PFS polymer brushes. This is attributed to the ordered PFOA film presenting aligned CF3 terminal groups. However, PFS polymer brushes were more effective in providing corrosion protection. These low energy surfaces could be used to provide a hydrophobic barrier that inhibits corrosion of the SS316L metal oxide surface. PMID:21631123

Kruszewski, Kristen M.

2011-01-01

353

The structure, properties and a resistance to abrasive wear of railway sections of steel with a different pearlite morphology  

Microsoft Academic Search

The article presents the characteristics of pearlite rail steels used in the construction of railways. The article discusses the influence of isothermal annealing process parameters on the pearlite morphology and properties of the R260 steel. The pearlite structure with a diverse pearlite morphology was obtained in the physical modeling of the isothermal annealing on the 3800 Gleeble Simulator. After the

K. Aniolek; J. Herian

2011-01-01

354

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

355

Improvement of Fatigue Strength of Maraging Steel by Shot Peening  

Microsoft Academic Search

Rotating bending fatigue tests up to 10 cycles were carried out to investigate the effects of shot peening on the fatigue strength and the fracture mechanism in wide range of fatigue life of an 18% Ni maraging steel by using shot particles of various sizes or hardness. Fatigue strength was increased markedly by shot peening in the wide region of fatigue

N. Kawagoishi; T. Nagano; M. Moriyama; E. Kondo

2009-01-01

356

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. Bauné; C. Chovet; B. Leduey; C. Bonnet

357

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

358

Tensile and fracture properties of type 316 stainless steel after creep  

NASA Astrophysics Data System (ADS)

The effects of creep on the mechanical properties of type 316 stainless steel were studied. Tensile and Charpy specimens were machined from the oversize specimens crept at 750 °C and 103 MPa. The ambient fracture energy was found to deteriorate rapidly after creep. The ambient yield stress was increased moderately, but the tensile ductility was severely reduced. The effects of intergranular carbides alone on mechanical properties were studied with specimens thermal aged without load. These carbides were shown to cause a moderate reduction in fracture energy and tensile ductility but had little effect on yield stress. Extensive grain boundary separations were observed on the fracture surfaces. SEM studies showed that these grain boundaries were covered with micro voids initiated by the dense intergranular carbides. Frequently, large dimples on grain boundary joined up and initiated shear fracture into the grain. In the crept specimens additional microstructural changes in the form of intragranular carbides and subgrain boundaries were observed. Both are responsible for the increase in yield stress and the further reduction in tensile ductility and fracture energy. The intragranular carbides also modified the size and density of the dimples on the fracture surfaces.

Gan, D.

1982-12-01

359

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 Å. 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

2014-08-01

360

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 Å. 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

361

Surface modification of superaustenitic and maraging stainless steels by low-temperature gas-phase carburization  

Microsoft Academic Search

Low-temperature gas-phase carburization of 316L austenitic stainless steel was developed in recent years by the Swagelok company. This process generates great mechanical and electrochemical surface properties. Hardness, wear resistance, fatigue behavior, and corrosion resistance are dramatically improved, while the formation of carbides is effectively suppressed. This new technique is of technical, economical, but especially of scientific interest because the surface

Johannes Gentil

2008-01-01

362

Evaluation of ageing-induced embrittlement in an austenitic stainless steel by instrumented impact testing  

NASA Astrophysics Data System (ADS)

Fracture properties of a thermally aged Type 316 stainless steel have been investigated at room temperature by an instrumented impact test. The impact energy is found to depend on the heat treatment conditions. Several alternative estimates for toughness are evaluated and compared with the conventional Charpy impact energy, C v, to assess the degree of embrittlement. Sensitivity of these parameters to monitor the ageing-induced embrittlement in comparison with C v is discussed.

Samuel, K. G.; Sreenivasan, P. R.; Ray, S. K.; Rodriguez, P.

1987-09-01

363

316L Stainless Steel with Gradient Porosity Fabricated by Selective Laser Melting  

Microsoft Academic Search

To fabricate 316L stainless steel part with a pore gradient structure, the method using selective laser melting (SLM) technique\\u000a is exploited. Scan tracks feature, densification, and tensile property of SLM-produced samples prepared via different scan\\u000a speeds were investigated. The results show that the porosity is strongly influenced by scan speed. On this basis, a gradient\\u000a changed scan speed was applied

Ruidi Li; Jinhui Liu; Yusheng Shi; Mingzhang Du; Zhan Xie

2010-01-01

364

Improvement of the forgability of 17-4 precipitation hardening stainless steel by ausforming  

Microsoft Academic Search

The ausforming process for 17-4 precipitation hardening (17-4PH) stainless steel is compared with the conventional warm-forging process, from the point of both the forgeability and the properties of the forged material. The forgeability is evaluated by upsetting, forward rod extrusion and backward can extrusion. The forging force required in ausforming is about half that required in conventional warm-forging: it especially

Sachihiro Isogawa; Hiroaki Yoshida; Yuzo Hosoi; Yasuhisa Tozawa

1998-01-01

365

Improvement of wear and corrosion resistances of 17-4PH stainless steel by plasma nitrocarburizing  

Microsoft Academic Search

17-4PH stainless steel was plasma nitrocarburized at 460°C for improving its mechanical properties without compromising its desirable corrosion resistance. The plasma nitrocarburized layers were studied by optical microscope, X-ray diffractometer, microhardness tester, pin-on-disc tribometer and the anodic polarization method in a 3.5% NaCl solution. The experimental results show that the nitrocarburized layer depths increase with increasing duration time and the

R. L. Liu; M. F. Yan

2010-01-01

366

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

367

Easy-to-clean property and durability of superhydrophobic flaky ?-alumina coating on stainless steel in field test at a paper machine  

NASA Astrophysics Data System (ADS)

Superhydrophobic flaky ?-alumina coating was prepared on AISI 316 2B stainless steel and was field-tested near size roll at a paper machine in a paper mill for 6 weeks consisting of two running periods of machine to check the easy-to-clean property and durability, as compared to an uncoated reference stainless steel. In the end of the field test, both the superhydrophobic and the reference stainless steel were fully covered with substances from the testing environment. Major part of the collected substances on the superhydrophobic stainless steel can be washed away by pressurized water; however, the collected substances remained on the reference stainless steel after washing. The field-tested samples were characterized visually and by stereomicroscopy, field emission scanning electron microscopy, laser profilometry and contact angle tester. The field test revealed the easy-to-clean property of the superhydrophobic surface and the superhydrophobic coating survived rather well after the first running period of 16 days in the field test. The resistance and durability of the superhydrophobic surface still needs to be further improved for longer term application in paper industry. Nanoindentation was used to further study the mechanical properties of the ?-alumina coating. It was found that the ?-alumina coating became much softer after transforming from flat to flaky form. In addition, the flaky ?-alumina coating demonstrated a phenomenon of time-dependent plasticity and some flexibility.

Zhang, Xiaoxue; Liu, Xuwen; Laakso, Jarmo; Levänen, Erkki; Mäntylä, Tapio

2012-01-01

368

Effect of ? -ferrite on impact properties of supermartensitic stainless steel heat affected zones  

Microsoft Academic Search

The work presented in this paper focuses on the effect 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 of the present study, subjected to a series of high temperature furnace heat treatments. Three microstructures possessing variable ferrite content and

D. Carrouge; H. K. D. H. Bhadeshia; P. Woollin

2004-01-01

369

Fatigue properties and failure characterization of spot welded high strength steel sheet  

Microsoft Academic Search

Fatigue properties and failure characterization of high strength spot welded steels, such as DP600 GI, TRIP600-bare and HSLA340Y GI, have been conducted. Tensile shear and coach peel samples have been used in this investigation. HSLA340Y GI samples were used as the baseline material for comparison. Microhardness was measured to study the hardness change across the weld nugget. Under low load

Xin Long; Sanjeev K. Khanna

2007-01-01

370

The microstructural, mechanical, and fracture properties of austenitic stainless steel alloyed with gallium  

Microsoft Academic Search

The mechanical and fracture properties of austenitic stainless steels (SSs) alloyed with gallium require assessment in order\\u000a to determine the likelihood of premature storage-container failure following Ga uptake. AISI 304 L SS was cast with 1, 3,\\u000a 6, 9, and 12 wt pct Ga. Increased Ga concentration promoted duplex microstructure formation with the ferritic phase having\\u000a a nearly identical composition

D. G. Kolman; J. F. Bingert; R. D. Field

2004-01-01

371

Dynamic fracture toughness and Charpy impact properties of an AISI 403 martensitic stainless steel  

Microsoft Academic Search

Dynamic fracture toughness and Charpy impact properties of a normalised and tempered AISI 403 martensitic stainless steel obtained from instrumented impact tests are presented. Procedures for estimating dynamic fracture toughness (KId) from the load-time traces obtained in instrumented tests of unprecracked Charpy V-notch (CVN) specimens are considered. The estimated KId values show reasonable agreement with those obtained from instrumented drop-weight

P. R Sreenivasan; S. K Ray; S. L Mannan; P Rodriguez

1996-01-01

372

Martensitic stainless steel AISI 420—mechanical properties, creep and fracture toughness  

Microsoft Academic Search

In this paper some experimental results and analyses regarding the behavior of AISI 420 martensitic stainless steel under\\u000a different environmental conditions are presented. That way, mechanical properties like ultimate tensile strength and 0.2 percent\\u000a offset yield strength at lowered and elevated temperatures as well as short-time creep behavior for selected stress levels\\u000a at selected elevated temperatures of mentioned material are

J. Brnic; G. Turkalj; M. Canadija; D. Lanc; S. Krscanski

373

Tensile properties of 0.05 to 0.20 Pct C TRIP steels  

Microsoft Academic Search

The uniaxial tensile properties of a series of TRIP steels of varying carbon contents and processing histories were determined\\u000a over a wide range of test temperatures. The yield strengths at room temperature varied both with the deformation temperature\\u000a (over the range 250 to 550C) and with the carbon content (0.05 to 0.20 pct). Possible reasons for these variations are advanced.

G. R. Chanani; V. F. Zackay; Earl R. Parker

1971-01-01

374

Tensile Properties and Work Hardening Behavior of Laser-Welded Dual-Phase Steel Joints  

Microsoft Academic Search

The aim of this investigation was to evaluate the microstructural change after laser welding and its effect on the tensile\\u000a properties and strain hardening behavior of DP600 and DP980 dual-phase steels. Laser welding led to the formation of martensite\\u000a and significant hardness rise in the fusion zone because of the fast cooling, but the presence of a soft zone in

N. Farabi; D. L. Chen; Y. Zhou

2011-01-01

375

Structural and mechanical properties of welded joints of reduced activation martensitic steels  

Microsoft Academic Search

Gas tungsten arc welding and electron beam welding methods were used to realise welding pools on plates of reduced activation martensitic steels. Structural and mechanical features of these simulated joints have been investigated in as-welded and post-welding heat-treated conditions. The research allowed to assess how each welding technique affects the original mechanical properties of materials and to find suitable post-welding

G. Filacchioni; R. Montanari; M. E. Tata; L. Pilloni

2002-01-01

376

The effects of austenite on the cryogenic mechanical properties of Fe?13Mn?3Al steel  

Microsoft Academic Search

This article reports the results of an investigation on the effects of austenite on the cryogenic mechanical properties of\\u000a Fe-13Mn-3Al steel. The volume fraction of austenite varied from 4% to a maximum of 70%, according to tempering temperature\\u000a and time. In the study, the morphology of austenite changed from the interlath type at below 550°C to block type at above

Hyung Chul Lee; Hu-Chul Lee

1997-01-01

377

Detection of localized fatigue damage in steel by thermography  

Microsoft Academic Search

Fatigue damage of unalloyed steels in the high cycle regime is governed by localized cyclic plastic deformations and subsequent crack initiation. The extent of early microplastic deformations depends on the applied stress level, stress concentration at macroscopic notches, surface treatment, residual stresses etc. The onset of a nonlinear material response can be regarded as an early indicator of fatigue damage.

Justus Medgenberg; Thomas Ummenhofer

2007-01-01

378

Steel corrosion by methanol combustion products: Enhancement and inhibition  

Microsoft Academic Search

Burning methanol produces formic acid, which can cause steel corrosion at temperatures below the dew point of the exhaust gas. Because of the potential of methanol as an alternate automotive fuel, it is of interest to evaluate the conditions, which can aggravate or mitigate the extent of this rust formation. Rust formation is promoted by such methanol contaminants, as organic

K. Otto; R. O. Carter; C. A. Gierczak; L. Bartosiewicz

1986-01-01

379

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 µm 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

380

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

NASA Astrophysics Data System (ADS)

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

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

381

Natural and synthetic rubber coatings for steel: Properties and compositions. (Latest citations from World Surface Coatings Abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the application of compositions containing natural and synthetic rubbers to steel. Polyurethane elastomers, chlorinated rubber coatings, and rubber containing acrylic adhesives are among the coatings discussed. Studies of the degradation of rubber coatings applied to steel are included. Bonding properties, adhesion strength, weathering, and anticorrosive properties are discussed. Additional information on anticorrosive coatings may be found in other bibliographies. (Contains a minimum of 147 citations and includes a subject term index and title list.)

Not Available

1993-03-01

382

Natural and synthetic rubber coatings for steel: Properties and compositions. (Latest citations from World Surface Coatings abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the application of compositions containing natural and synthetic rubbers to steel. Polyurethane elastomers, chlorinated rubber coatings, and rubber containing acrylic adhesives are among the coatings discussed. Studies of the degradation of rubber coatings applied to steel are included. Bonding properties, adhesion strength, weathering, and anticorrosive properties are discussed. Additional information on anticorrosive coatings may be found in other bibliographies. (Contains a minimum of 180 citations and includes a subject term index and title list.)

Not Available

1994-04-01

383

Effect of welding on local mechanical properties of stainless steels for concrete structures using universal hardness tests  

Microsoft Academic Search

This study analyses the effect of welding on mechanical properties of ribbed bars of two cold-deformed austenitic stainless steels (new, low-nickel AISI 204Cu and traditional 304L types) and two duplex stainless steels (SAF 2205 type, cold and hot-worked). Welds have been carried out using shielded metal arc welding. The effect of welding on local mechanical properties has been studied using

F. Velasco; G. Blanco; A. Bautista; M. A. Martínez

2009-01-01

384

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

385

Mechanical Properties of Laser Heat Treated 6 mm Thick UHSS-Steel  

SciTech Connect

In this work abrasion resistant (AR) steel with a sheet thickness of 6 mm was heat treated by a 4 kW Nd:YAG and a 4 kW Yb:Yag-laser, followed by self-quenching. In the delivered condition, test material blank (B27S) is water quenched from 920 deg. C. In this condition, fully martensitic microstructure provides excellent hardness of over 500 HB. The test material is referred to AR500 from now onwards. Laser heat treatment was carried out only on top surface of the AR500 sheet: the achieved maximum temperature in the cross-section varies as a function of the depth. Consequently, the microstructure and mechanical properties differ between the surfaces and the centre of the cross-section (layered microstructure). For better understanding, all layers were tested in tensile tests. For a wide heat treatment track, the laser beam was moved by scanning. Temperatures were measured using thermographic camera and thermocouples. Laser heat treated AR500 samples were tested in hardness tests and by air bending using a press brake machine. Microstructures were studied using a light microscope and FE-SEM/SEM-EBSD. At least three kind of microstructure layers were observed: 1) Dual-Phase ferritic/martensitic (T = A{sub C1}-A{sub C3}), 2) ferritic (T{approx}A{sub C3}) and 3) bainitic/martensitic (T>A{sub C3}).

Jaervenpaeae, Antti; Maentyjaervi, Kari; Maeaettae, Antti; Hietala, Mikko [University of Oulu, Oulu Southern Institute, Pajatie 5, FIN-85500 Nivala (Finland); Merklein, Marion [University of Erlangen-Nuremberg, Chair of Manufacturing Technology (Germany); Karjalainen, Jussi [University of Oulu, Department of Mechanical Engineering, P.O. BOX 4200, FIN-90014 (Finland)

2011-05-04

386

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

387

Mechanical Properties of Laser Heat Treated 6 mm Thick UHSS-Steel  

NASA Astrophysics Data System (ADS)

In this work abrasion resistant (AR) steel with a sheet thickness of 6 mm was heat treated by a 4 kW Nd:YAG and a 4 kW Yb:Yag-laser, followed by self-quenching. In the delivered condition, test material blank (B27S) is water quenched from 920° C. In this condition, fully martensitic microstructure provides excellent hardness of over 500 HB. The test material is referred to AR500 from now onwards. Laser heat treatment was carried out only on top surface of the AR500 sheet: the achieved maximum temperature in the cross-section varies as a function of the depth. Consequently, the microstructure and mechanical properties differ between the surfaces and the centre of the cross-section (layered microstructure). For better understanding, all layers were tested in tensile tests. For a wide heat treatment track, the laser beam was moved by scanning. Temperatures were measured using thermographic camera and thermocouples. Laser heat treated AR500 samples were tested in hardness tests and by air bending using a press brake machine. Microstructures were studied using a light microscope and FE-SEM/SEM-EBSD. At least three kind of microstructure layers were observed: 1) Dual-Phase ferritic/martensitic (T = AC1-AC3), 2) ferritic (T˜AC3) and 3) bainitic/martensitic (T>AC3).

Järvenpää, Antti; Mäntyjärvi, Kari; Merklein, Marion; määttä, Antti; Hietala, Mikko; Karjalainen, Jussi

2011-05-01

388

Microstructure properties of tempered D6ac steel  

NASA Astrophysics Data System (ADS)

The aim of this study was to determine the microstructure and surface mechanical properties of tempered D6ac. The obtained microstructures exhibited a number of misfit dislocations from work hardening, with the degree of disorder dislocation decreasing gradually upon increasing the temperature at 650 °C. XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides at 650 °C will result in a softer state than that of the room temperature specimen. In addition, the forming process has a high microhardness of martensite phase at surface layer, subjected to heat treatment until a stable state is achieved. The content of ferrite atoms decreased and that of carbon and chromium elements increased upon increasing the tempering temperature.

Lian, Derming

2013-01-01

389

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

390

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

391

Prior thermo-mechanical processing to modify structure and properties of severely deformed low carbon steel  

NASA Astrophysics Data System (ADS)

The article focuses on the severe plastic deformation (SPD) of low carbon steel AISI 1010 performed at increased temperature. The grain refinement of ferrite structure is monitored and described with respect to different initial steel structure modified by thermal and thermomechanical (TM) treatment (TM) prior severe plastic deformation. The refinement of coarse initial ferrite structure with grain size in range of 30 – 50 gm resulted from solutioning was conducted then in two steps. Preliminary structure refinement has been achieved due to multistep open die forging process and quite uniform ferrite structure with grain size of the order of gm was obtained. The further grain refinement steel structure was then accomplished during warm Equal Channel Angular Pressing (ECAP phi = 120°) at 300°C, introducing different strain in range of ?ef = 2.6 -4. The change of microstructure in dependence of the effective strain was evaluated by SEM and TEM study of thin foils. The high straining of steel resulted in extensive deformation of ferrite grains and formation of mixture of submicron grains structure in banded deformed structure with dense dislocation network and subgrains. The dynamic polygonization process, due to increased ECAP temperature, modified the submicrocrystalline structure formation. There was only indistinctive difference observed in structure refinement when considering different initial structure of steel. The tensile behaviour was characterized by strength increase followed by softening. None work hardening phenomenon appeared at tensile deformation of deformed bars.

Zrnik, J.; Lapovok, R.; Raab, G. I.

2014-08-01

392

Effects of strain-rate and pre-fatigue on tensile properties of laser welded joint of high strength steel plates  

Microsoft Academic Search

The impact tensile properties of laser welded butt joints of two kinds of high strength steel plates with the tensile strength level of 590 MPa and 780 MPa (denoted by HR590 and HR780, respectively), were investigated using split Hopkinson bar tensile testing apparatus. Impact tension tests for the joint specimens pre-fatigued were also carried out to examine the effect of

H. Kobayashi; M. Daimaruya; H. Tsuda; K. Horikawa

2006-01-01

393

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

2014-08-01

394

Effect of Cyclic Aging on Mechanical Properties and Microstructure of Maraging Steel 250  

NASA Astrophysics Data System (ADS)

The effects of thermal cyclic aging on mechanical properties and microstructure of maraging steel 250 were studied using hardness tester, tensile testing machine, impact tester, optical, scanning electron, and stereo microscopy. Samples were solution annealed at 1093 K for 1 h followed by air cooling to form bcc martensite. Cyclic aging treatments were carried out at 753 and 773 K for varying time periods. Increase in hardness and strength with corresponding decrease in ductility and impact strength was observed with increasing aging cycles. Reverted austenite was detected by x-ray diffraction technique formed as a result of cyclic aging. The presence of reverted ? was also confirmed by EDX-SEM analysis and attributed to the formation of Mo- and Ni-rich regions which transformed to ? on cooling. Heterogeneity in composition and amount of reverted ? was found to increase with increase in aging cycles and aging time. Fractography reveals the change in fracture mode from ductile dimple-like to brittle cleavage with increase in hardness and strength due to cyclic aging.

Tariq, Fawad; Naz, Nausheen; Baloch, Rasheed Ahmed

2010-10-01

395

Austenite stability and its influence on mechanical properties of 18-8 stainless steel at cryogenic temperatures. [SS 304LN  

SciTech Connect

Stress/strain induced martensitic transformation has been found to play an important role on the mechanical properties of metastable austenitic stainless steels. Typical two-stage stress-strain curves were observed for AISI 304L and 304LN stainless steels containing 18% Cr and 8%Ni. The martensite phase induced in the high-work-hardening stage was found, by transmission electron microscopy, to be accommodated by mechanical twinning. The drop of 0.2% offset yield strength caused by the dilation and induced slip associated with the martensitic transformation of the low-carbon-content 304L was observed at liquid nitrogen temperature. Low temperature favorable fatigue properties were observed for 304L but not for 304LN. Below the M/sub d/ temperature, the fatigue crack propagation in metastable austenitic steels can be assumed to be the same as crack growth in an austenite and martensite composite. Although fatigue cracks grew faster in the martensite phase than in the austenite phase, the compressive stress near the crack tip due to the martensitic transformation appeared to reduce the effective stress intensity range which resulted in a decreased crack growth rate. The controlling factor became K/sub max/ instead of ..delta.. K if the load ratio R was not large. The addition of interstitial nitrogen, which stabilizes the austenite phase, reduced the compressive stress at crack tips and resulted in the temperature-insensitive fatigue properties. Both the austenite phase and the martensite phase were found to be ductile at liquid nitrogen temperature.

Chang, G.M.

1983-06-01

396

Laser-assisted structuring of ceramic and steel surfaces for improving tribological properties  

NASA Astrophysics Data System (ADS)

Tribological properties of a system are very important for saving energy or increasing service life as in automotive industry. It is known that wear and friction behaviour is strongly influenced by the topography of the mated surfaces. In case of lubricated sliding contact the tribological properties can be improved by generating a defined surface structure in form of small channels or isolated pits. Depending on the structure it may act as a reservoir for the lubricant and hampers the drain of the lubricant. In addition, wear particles can be removed from the contact area and can be collected inside the structures. In the present paper, a Nd:YAG-laser was used to generate different structures on ceramic (Al 2O 3) and steel (100Cr6) surfaces. Microchannels and micropits were generated onto an otherwise flat surface by a laser ablation process. Due to the high flexibility of the laser system, structural features such as size, density and orientation could be varied easily by changing the laser parameters. The effects of different topographies on friction and wear behaviour were examined using a cylinder/plate tribometer for lubricated and reversed sliding contact. Laser structured 100Cr6 and alumina surfaces mated to 100Cr6 cylinders showed that a reduction of friction could be achieved in comparison to the polished surfaces. Dependent on the kind of the surface structure the coefficient of friction could be reduced up to 30%, especially in the initial period of the tribological experiment. The results show that the laser technique is an effective tool to optimise the topography of tribological surfaces.

Schreck, S.; Zum Gahr, K.-H.

2005-07-01

397

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

398

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

SciTech Connect

Precipitation-strengthened martensitic stainless steels provide excellent strength (170--220 ksi Y.S.) with high corrosion resistance. However, upon aging, a large reduction in toughness may also occur. The gas tungsten arc (GTA) cold wire feed process was used to weld half inch thick plates of PH 13-8 Mo and Custom 450 from which both tensile and Charpy specimens were machined. A fundamental understanding of the details of weld microstructural evolution was developed by liquid tin quenching GTA welds in which the solidification behavior, primary phase of solidification, microsegregation, and solid-state transformations could be followed. For both alloys studied, the as-welded yield strengths were similar to those of the unaged base material, 130 ksi. Weld properties were very similar to those of the base materials for both alloy systems. Weld strength increases significantly upon aging and achieves a maximum at intermediate aging temperatures. The increase in strength is accompanied by a large decrease in Charpy impact energy; however, the minimum in toughness occurs at aging temperatures slightly less than those resulting in peak strengths. The evolution of the weld microstructure was found to support predictions of microstructural modeling. Although a high degree of alloying partitioning occurs during solidification, a large degree of homogenization occurs upon further solidification and cooling as a result of solid-state diffusion.

Brooks, J.

1994-12-31

399

Design by analysis versus design by formula of high strength steel pressure vessels: a comparative study  

Microsoft Academic Search

A comparative study for design by analysis and design by formula of a cylinder to nozzle intersection has been made using different finite element techniques. The cylinder to nozzle intersection investigated is part of a typical vertical pressure vessel with a skirt support. For the study the commonly used ductile P355 steel alloy and the high strength steel alloy P500

A. Th. Diamantoudis; Th. Kermanidis

2005-01-01

400

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

401

Microstructure and Properties of Cast B-Bearing High Speed Steel  

NASA Astrophysics Data System (ADS)

Microstructure, mechanical properties, and wear resistance of B-bearing high-speed steel (HSS) roll material containing 0.90-1.00% C, 1.3-1.5% B, 0.8-1.5% W, 0.8-1.5% Mo, 4.6-5.0% Cr, 1.0-1.2% V, and 0.15-0.20% Ti were studied by means of the optical microscopy (OM), the scanning electron microscopy (SEM), x-ray diffraction (XRD), hardness, impact toughness, and pin-on-disk abrasion tests. The results showed that as-cast structure of B-bearing HSS consisted of ?-Fe-, M23(B,C)6-, M3(B0.7C0.3)-, and M2(B,C)-type borocarbides, a small quantity of retained austenite, and a small amount of TiC. The hardness and impact toughness values of as-cast B-bearing HSS reached 65-67 HRC and 80-85 kJ/cm2, respectively. There were many M23(B,C)6-precipitated phases in the matrix after tempering, and then, with increasing temperature, the amount of precipitated phases increased considerably. Hardness of B-bearing HSS gradually decreased with the increasing tempering temperature, and the change of tempering temperature had no obvious effect on impact toughness. B-bearing HSS tempered at 500 °C has excellent wear resistance, which can be attributed to the effect of boron.

Fu, Hanguang; Ma, Shengqiang; Hou, Jianqiang; Lei, Yongping; Xing, Jiandong

2013-04-01

402

Effect of cyclic cryogenic treatment on the properties and structure of 40CrNiMoA steel  

NASA Astrophysics Data System (ADS)

In this work, the effect of different treatment processes on properties and structure of 40CrNiMoA steel after temperature cycling experiments were studied. Different treatment processes contained that heat treatment (HT), cryogenic treatment before tempering (CT-1) and cryogenic treatment after tempering (CT-2). After that, some samples of the different treatment processes were done by temperature cycling experiments, which was cooled from room temperature to -190°C for 4 hours, then heated from -190°C to 125°C for 4 hours, at last cooled to the room temperature. The temperature cycling experiments were repeated fifteen times. The rate of cooling and heating was 4°C/min. Both the quenching and tempering were done in a vacuum furnace. All the cryogenic treatments and temperature cycling experiments of fifteen times were done in a program-controlled cryogenic container. The results show that, the strength and plasticity achieve the optimal matching, when 40CrNiMoA steel was done by cryogenic treatment after tempering (CT-2). At the same time the microstructure of the steel is homogeneous, and the performance gets more stable after temperature cycling experiments. The performance of 40CrNiMoA has not deteriorative phenomenon after temperature cycling experiments. Therefore, compared to the heat treatment (HT) and cryogenic treatment before tempering (CT-1), the cryogenic treatment after tempering(CT-2) can improve the comprehensive performance of 40CrNiMoA steel. It also can increase the attended performance and working life in the formidable natural condition.

Zhang, H.; Gu, K. X.; Wang, J. J.; Zhou, Y.; Guo, J.; Cui, C.

2014-01-01

403

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

404

The effects of novel surface treatments on the wear and fatigue properties of steel and chilled cast iron  

NASA Astrophysics Data System (ADS)

Contact fatigue driven wear is a principal design concern for gear and camshaft engineering of power systems. To better understand how to engineer contact fatigue resistant surfaces, the effects of electroless nickel and hydrogenated diamond-like-carbon (DLC) coatings on the fatigue life at 108 cycles of SAE 52100 steel were studied using ultrasonic fatigue methods. The addition of DLC and electroless nickel coatings to SAE 52100 bearing steel had no effect on the fatigue life. Different inclusion types were found to affect the stress intensity value beyond just the inclusion size, as theorized by Murakami. The difference in stress intensity values necessary to propagate a crack for Ti (C,N) and alumina inclusions was due to the higher driving force for crack extension at the Ti (C,N) inclusions and was attributed to differences in the shape of the inclusion: rhombohedral for the Ti (C,N) versus spherical for the oxides. A correction factor was added to the Murakami equation to account for inclusion type. The wear properties of DLC coated SAE 52100 and chilled cast iron were studied using pin-on-disk tribometry and very high cycle ultrasonic tribometry. A wear model that includes sliding thermal effects as well as thermodynamics consistent with the wear mechanism for DLCs was developed based on empirical results from ultrasonic wear testing to 108 cycles. The model fit both ultrasonic and classic tribometer data for wear of DLCs. Finally, the wear properties of laser hardened steels - SAE 8620, 4140, and 52100 - were studied at high contact pressures and low numbers of cycles. A design of experiments was conducted to understand how the laser processing parameters of power, speed, and beam size, as well as carbon content of the steel, affected surface hardness. A hardness maximum was found at approximately 0.7 wt% carbon most likely resulting from increased amounts of retained austenite. The ratcheting contact fatigue model of Kapoor was found to be useful in predicting the wear results. The empirical model of Clayton and Su and extended by Afferente and Ciavarella, also provided reasonable semi-quantitative contact fatigue life models for these steels.

Carroll, Jason William

405

Low Cycle Fatique Crack Propagation Characteristics of High Strength Steels.  

National Technical Information Service (NTIS)

The fatigue crack growth properties of various high strength steels, including the 250 and 300 grades of the 18Ni-Co-Mo maraging steel, H11 steel, and D6A steel, have been studied using a centercracked specimen. Experiments were conducted by cycling eithe...

C. M. Carman, J. M. Katlin

1966-01-01

406

Encapsulation of steel foundry bag house dusts in cement mortar  

Microsoft Academic Search

The purpose of this study was to investigate the properties of bag house dusts generated by steel foundries when stabilized with Portland cement at high levels of cement addition. The main bag house dust studied was obtained as a byproduct of steel manufacture, at Pacific Steel Limited in Auckland, New Zealand, whereas others were sourced from BHP New Zealand Steel,

Ian W Hamilton; Nigel M Sammes

1999-01-01

407

Hydrogen-Induced Cracking in GMA Welds of Vanadium–Titanium Microalloyed High Strength Steel  

Microsoft Academic Search

High strength low alloy (HSLA) steels are developed to provide better strength, toughness, and improved weldability. These steels are often used as better alternatives for quenched and tempered steels due to the excellent combination of these properties. The beneficial properties in these steels are achieved by careful control of composition and by adopting suitably controlled thermomechanical processing (TMCP). Improved weldability

K. Venkatesan; R. Sivasankari; V. Balusamy; Atul Saxena; Priti Jha; Ramen Datta

2010-01-01

408

Effect of Zinc Coatings on Joint Properties and Interfacial Reactions in Aluminum to Steel Ultrasonic Spot Welding  

NASA Astrophysics Data System (ADS)

Dissimilar joining of aluminum to steel sheet in multimaterial automotive structures is an important potential application of ultrasonic spot welding (USW). Here, the weldability of different zinc-coated steels with aluminum is discussed, using a 2.5-kW USW welder. Results show that soft hot-dipped zinc (DX56-Z)-coated steel results in better weld performance than hard (galv-annealed) zinc coatings (DX53-ZF). For Al to hard galv-annealed-coated steel welds, lap shear strengths reached a maximum of ~80% of the strength of an Al-Al joint after a 1.0 s welding time. In comparison, welds between Al6111-T4 and hot dipped soft zinc-coated steel took longer to achieve the same maximum strength, but nearly matched the Al-Al joint properties. The reasons for these different behaviors are discussed in terms of the interfacial reactions between the weld members.

Haddadi, F.; Strong, D.; Prangnell, P. B.

2012-03-01

409

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 500-600°C 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

410

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

411

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

412

Tribological properties of novel imidazolium ionic liquids bearing benzotriazole group as the antiwear/anticorrosion additive in poly(ethylene glycol) and polyurea grease for steel/steel contacts.  

PubMed

The imidazolium ionic liquids (ILs) bearing benzotriazole group were synthesized and evaluated as antiwear (AW) and anticorrosion additive in poly(ethylene glycol) (PEG) and polyurea grease for steel/steel contacts at room temperature and 150 °C. The physical properties of the synthetic ILs and PEG with the additive were measured. The anticorrosion property of the synthetic ILs was assessed via the accelerated corrosion test and copper strip corrosion test, which reveals the excellent anticorrosion properties in comparison with pure PEG and the selected conventional ILs having no benzotriazole group. Tribological results indicated that these ILs as the additives could effectively reduce friction and wear of sliding pairs in PEG and also in polyurea grease. The tribological properties were generally better than the normally used zincdialkyldithiophosphate-based additive package (T204) in polyurea grease. The wear mechanisms are tentatively discussed according to the morphology observation of worn surfaces of steel discs by scanning electron microscope (SEM) and the surface composition analysis by X-ray photoelectron spectroscopy (XPS). PMID:22026637

Cai, Meirong; Liang, Yongmin; Zhou, Feng; Liu, Weimin

2011-12-01

413

On the nature of high-strength state of carbon steel produced by severe plastic deformation  

NASA Astrophysics Data System (ADS)

Contributions of different strengthening mechanisms to yield strength of carbon steels C 10 (0.1 % C) and C 45 (0.45 % C) with ultrafine-grained microstructures have been analyzed in this work based on the precision investigation of the microstructure by electron microscopy, 3D atom probe tomography, and mechanical properties. Estimated values of yield stress showed satisfactory agreement with the experimental results. It is shown that significant contribution to strengthening is made by carbides. In particular, as the carbon content increases in carbon steels, the volume fraction of cementite increases and, accordingly, there is a bigger deviation of the yield strength value from the classical Hall-Petch relationship. The relative contribution of grain boundary strengthening into the yield stress is reduced due to an increased proportion of precipitate strengthening.

Ganeev, Artur V.; Karavaeva, Marina V.; Sauvage, Xavier; Courtois-Manara, Eglantine; Ivanisenko, Yulia; Valiev, Ruslan Z.

2014-08-01

414

Undergraduate Research: Cory Tamler By: Bruce Steele  

E-print Network

more computational power than that of a slide rule or calculator." "As someone who is deeply interested plays by Tom Stoppard, Hapgood (which combines themes of espionage and quantum physics) and Arcadia (in

Jiang, Huiqiang

415

Properties of the stainless steel substrate, influencing the adhesion of thermo-resistant streptococci  

Microsoft Academic Search

The quality of products produced by dairy manufacturing plant is threatened when bacteria attached to and growing (biofilm formation) on stainless steel are released into the product stream. The adhesion of bacteria to the surface is the first stage in this process and enables subsequent proliferation and release. In the present trial, thermo-resistant streptococci were found to adhere preferentially to

S. H. Flint; J. D. Brooks; P. J. Bremer

2000-01-01

416

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

417

Mechanical properties and fracture characteristics of high carbon steel after equal channel angular pressing  

E-print Network

was fabricated in a fully pearlitic Fe­0.8 wt% C steel after equal channel angular pressing (ECAP) at 923 K via spheroidized by increasing the number of ECAP passes. After four passes, the cementite lamellae are fully and percentage of reduction in area increase with the number of ECAP passes. The tensile fracture morphology

Volinsky, Alex A.

418

Influence of Hot Press Forming Techniques on Properties of Vehicle High Strength Steels  

Microsoft Academic Search

Based on the combination of materials science and mechanical engineering, hot press forming process of the vehicle high strength steels was analyzed. The hot forming process included: heating alloys rapidly to austenite microstructures, stamping and cooling timely, maintaining pressure and quenching. The results showed that most of austenite microstructure was changed into uniform martensite by the hot press forming while

Ying CHANG; Zhao-huan MENG; Liang YING; Xiao-dong LI; Ning MA; Ping HU

2011-01-01

419

Mechanical properties of 17-4PH stainless steel foam panels  

Microsoft Academic Search

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 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

S. V. Raj; L. J. Ghosn; B. A. Lerch; M. Hebsur; L. M. Cosgriff; J. Fedor

2007-01-01

420

An investigation on surface properties of treated low carbon and alloyed steels (boriding and carburizing)  

Microsoft Academic Search

In this study, the wear behaviour of the borided and carburized AISI 1020 and 5115 steels are investigated. Some of the samples prepared from test materials are carburized and some borided. The microstructure, worn surface and hardness distribution of the samples are examined. After and before wear testing, the surface phases of the treated samples are determined by X-ray diffraction

B Selçuk; R Ipek; M. B Karami?; V Kuzucu

2000-01-01

421

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

SciTech Connect

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 of solid-state diffusion. The welds in all three alloys exhibited good resistance to solidification cracking and generally exhibited tensile and impact properties similar to those of the base metal. However, in almost all cases, the weld Charpy impact energies were somewhat less than those of the base metals. The cracking behavior and mechanical properties are discussed in terms of microstructural evolution.

Brooks, J.A. (Sandia National Labs., Livermore, CA (United States)); Garrison, W.R. Jr. (Carnegie-Mellon Univ., Pittsburgh, PA (United States))

1999-08-01

422

Hydrogen Environment Embrittlement Evaluation in Fatigue Properties of Stainless Steel SUS304L at Cryogenic Temperatures  

NASA Astrophysics Data System (ADS)

A very simple and safe mechanical properties testing procedure to evaluate hydrogen environment embrittlement (HEE) in the environment of high pressure and low temperature hydrogen has been developed. In this method, the high-pressure hydrogen environment is produced just inside the hole in the specimen. In this work, the effect of HEE on fatigue property for an austenitic stainless steel SUS304L was evaluated at 298, 190, and 20 K. The tests at 20 K were carried out using a cryostat with a Gifford-McMahan (GM) refrigerator. It took about 10 hours to cool specimens from room temperature to 20 K in the cryostat. The effect of HEE in fatigue properties was observed at higher stress level in room temperature and 190 K, but it was not clear at 20 K.

Ogata, T.

2010-04-01

423

Mould steels repaired by laser welding  

Microsoft Academic Search

Laser-deposit welding, by using Nd-YAG, is a mould repairing process, which has the advantages relatively to the traditional methods of achieving a less change of the metal composition around the repaired zone and permitting a very accurate deposition of a small volume of the filler material in the area chosen at the work-piece surface. This paper presents a fatigue study

L. P. Borrego; J. T. B. Pires; J. M. Costa; J. M. Ferreira

2009-01-01

424

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

425

Quantitative nondestructive electronic and magnetic property assessment of heat treated grade p91 steel  

NASA Astrophysics Data System (ADS)

Structural steels experience aging from fatigue, creep and corrosion. Prolonged high temperature service accelerates creep and stress-corrosion cracking. Microstructural degradation of structural steels is a serious problem that limits the integrity of high-temperature parts in power plants. Some power plants that utilize fossil fuels have experienced lifecycle issues with heat-treated steel alloys that have experienced progressive damage over time. A nondestructive technique for the evaluation of the microstructure of key structural materials and the prediction of lifecycle has been the focus of extensive research for many years. Advanced nondestructive wave assessment techniques are being developed using electronic and magnetic perturbation analysis. These methods are applied to ferrous materials to determine whether a designed heat-treatment provides an acceptable microstructure offering specific set of required properties for the full service life of the component. The methods used in this research include impedance spectroscopy and hysteresis measurement as preliminary assessment methods and hysteresis frequency analysis and Barkhausen noise measurement as secondary assessment methods.

Meir, Shai Shmuel

426

Properties of low-carbon 25 Mn-5Cr-1 Ni austenitic steel for cryogenic use  

SciTech Connect

The intent of the authors is to develop a new nonmagentic manganesechromium austenitic steel for cryogenic use. Following a trial investigation of a fundamental alloy system, and on the basis of the microstructure, notch toughness, magentic permeability, and austenitic stability, an alloy system of 0.15C-25Mn-5Cr-1Ni is selected as the base composition. Microalloying is then used to increase the strength; elements Nb, V, and Ti, up to 0.1%, are added separately to the base composition, and the subsequent alloys are then tested according to the same procedures as the base testing. Machinability, fatigue properties, and thermal expansion coefficients are also determined. These investigations yield a low-C 25Mn-Cr-1Ni-Nb-N steel which at cryogenic temperatures has high strength and toughness. At 4 K it is fully nonmagentic and possesses a proof strength above 850 MPa and a tensile strength well over 1450 MPa. All data indicate that this steel can be used as both a structural and nonmagnetic material for cryogenic uses.

Yoshimirura, H.; Inove, T.; Masumoto, H.

1982-01-01

427

Copper Precipitation Hardened, High Strength, Weldable Steel by Semyon Vaynman 1  

E-print Network

. Abstract Steel containing 0.03% carbon, 1.35% copper and 0.84% nickel had yield strength in the 540-625 MPa years an easily weldable, high strength (more than 540 MPa yield), high impact fracture toughness steelCopper Precipitation Hardened, High Strength, Weldable Steel by Semyon Vaynman 1 , Morris E. Fine 1

428

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 µm) 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.

2014-09-01

429

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

430

Effect of High-Temperature Severe Plastic Deformation on Microstructure and Mechanical Properties of IF Steel  

NASA Astrophysics Data System (ADS)

Extensive research work has been carried out on interstitial-free steel to understand its response to deformation; particularly, the behavior during severe plastic deformation (SPD). However, most of these studies were mainly undertaken in the ferritic regime. The present investigation reports the initial results of our attempt to employ accumulative roll bonding (ARB), one of the variants of SPD, at a high temperature (950 °C). A considerable grain refinement has been observed, which may be attributed to the severity of deformation and recrystallisation at high temperatures. Nanoindentation tests have been performed at various stages of ARB process to understand the evolution of mechanical properties.

Jindal, Vikas; Rupa, P. K. P.; Mandal, G. K.; Srivastava, V. C.

2014-06-01

431

Magnetic properties of grain oriented electrical steel in model transformer under direct current-biased magnetization  

NASA Astrophysics Data System (ADS)

Iron losses and acoustic noises of the model transformer under DC-biased magnetization were empirically investigated. To clarify the influence of magnetic properties of transformer core materials, two types of grain oriented electrical steels—high permeability grade (HGO) and conventional grade (CGO)—were used as core materials. Iron losses increased with superimposing DC-bias magnetic field (HDC) in both materials, and the iron loss increment in HGO was larger than that in CGO. Acoustic noises increased with increasing HDC in both materials; however, noises emitted from the core of HGO were smaller than those of CGO.

Inoue, Hirotaka; Okabe, Seiji

2014-05-01

432

The influence of aluminum on hot deformation behavior and tensile properties of high-Mn TWIP steels  

Microsoft Academic Search

The influence of aluminum (0–3wt.%) on the high-temperature flow stress and recrystallization kinetics of two austenitic 25wt.% Mn-bearing TWIP steels were investigated and compared with the behavior of a low-carbon steel. In addition, tensile properties were determined over the temperature range from ?80 to 200°C. It was observed that the hot deformation resistance is slightly higher for the 25Mn3Al than

A. S. Hamada; L. P. Karjalainen; M. C. Somani

2007-01-01

433

Natural and synthetic rubber coatings for steel: Properties and compositions. (Latest citations from World Surface Coatings abstracts). Published Search  

SciTech Connect

The bibliography contains citations concerning the development and fabrication of natural and synthetic rubbers for use in coatings on steel. Coating materials include polyurethane elastomers, chlorinated rubber, and rubber-containing acrylic adhesives. References to bonding properties, mechanical strength, steel-wire reinforced rubbers, anticorrosion, and weather-resistance are covered. (Contains 50-250 citations and includes a subject term index and title list.)

NONE

1995-07-01

434

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

435

Corrosion inhibition of carbon steel in 0.5 M NaCl aqueous solution by humid air plasma treatment  

NASA Astrophysics Data System (ADS)

Carbon steel (C75) is exposed to highly reactive species such as hydroxyl radicals OH created by a gliding arc discharge (GAD) in humid air at atmospheric pressure. The protective properties of carbon steel treated by GAD are studied versus different treatment times (t) and for an immersion in corroding 0.5 M sodium chloride solution during 24 h. Evolutions of corrosion rate are studied using weight loss measurements and electrochemical methods, e.g., electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization. The results obtained by GAD treatment show that the corrosion rate of steel decreases with the ennoblement of the corrosion potential and the decrease of the corrosion current density. This indicates that the plasma treatment acts as an anodic type inhibitor and suggests the formation of a protective layer. EIS measurements confirm the presence of this film: the charge transfer resistance (Rct) increases with GAD treatment time, leading to a corrosion inhibition efficiency around 73% for a treatment time equal to 60 min. This confirms the importance of the plasma effect. The gliding arc discharge is a clean and efficient technology for the surface treatment of carbon steel; it improves the anticorrosion properties of steel in aggressive environments, forming a resistant and insulating barrier.

Ghali, Noureddine; Addou, Ahmed; Mutel, Brigitte; Benstaali, Baghdad; Bentiss, Fouad; Brisset, Jean-Louis

2013-02-01

436

Evaluation of mechanical properties and nano-meso structures of 9-11%Cr ODS steels  

NASA Astrophysics Data System (ADS)

This study carried out mechanical tests and microstructural characterizations of several 9Cr and 11Cr-ODS tempered martensitic steels. From those results, the appropriate chemical composition range of 11Cr-ODS tempered martensitic steel was discussed from the viewpoint of high temperature strength improvement. It was shown that the residual ?-ferrite fraction in 11Cr-ODS steel was successfully controlled to the same level as the 9Cr-ODS steel, which has excellent high temperature strength, by selecting the chemical compositions on the basis of the multi-component phase diagram. The tensile strength decreased with decreasing W content from 2.0 to 1.4 wt%. On the other hand, creep strength at 973 K did not degrade by the decreasing W content. Both tensile strength and creep strength increased with increasing population of the nano-sized oxide particles. Small angle X-ray scattering analysis revealed that titanium and excess oxygen contents were key parameters in order to improve the dispersion conditions of nano-sized oxide particles.

Tanno, Takashi; Ohtsuka, Satoshi; Yano, Yasuhide; Kaito, Takeji; Oba, Yojiro; Ohnuma, Masato; Koyama, Shinichi; Tanaka, Kenya

2013-09-01

437

Effect of microstructure on the mechanical properties of a commercial 12Cr-1Mo steel (HT-9)  

SciTech Connect

The microstructure of a commercial 12Cr-1Mo steel (HT-9) and its associated effect on strength and toughness properties is being studied in a continuing program aimed at qualifying the alloy for use in fusion energy machines. Interim results show this alloy is subject to a degree of tempered martensite embrittlement and temper embrittlement. For applications projected for fusion machines at lower temperatures, a new heat treatment (1000/sup 0/C, 1 h, air-cooled followed by 650/sup 0/C tempering) at lower temperatures and shorter times than the vendor-recommended heat treatment has been identified. Microstructural differences between the treatments are discussed, and mechanical properties are correlated. 6 figures.

Lechtenberg, T.A.

1981-08-01

438

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

439

Correlation of flux composition and inclusion characteristics with submerged arc weld metal properties in HY-100 steel  

NASA Astrophysics Data System (ADS)

Submerged arc weldments of HY-100 steel prepared under standard conditions with five commercially available fluxes were analyzed to discern a basis for the variation in mechanical properties associated with different flux use. The variations in flux chemistry resulted in alloyed weldments with diverse weld metal mechanical properties as evident by Charpy impact, tensile, dynamic tear, and microhardness tests. The microstructures and macrostructures were examined using optical and electron microscopy in order to determine the basis for the variations in strength and toughness. Scanning electron microscope and energy dispersive x-ray experiments were performed to determine the size, type, distribution and volume fraction of the non-metallic inclusions in the weld metal. Inclusion characterization revealed that the role of the flux in alloying had a more significant effect on the strength and toughness than did the presence of specific inclusions.

Kettell, Kent W.

1993-09-01

440

Fatigue and fracture properties of a super-austenitic stainless steel at 295 K and 4 K  

NASA Astrophysics Data System (ADS)

The tie plate structure for the ITER Central Solenoid (CS) is required to have high strength and good fatigue and fracture behavior at both room temperature and 4 K. A super-austenitic stainless steel - UNS 20910, commonly referred to by its trade name, Nitronic 50 (N50) - has been chosen for consideration to fulfill this task, due to its good room temperature and cryogenic yield strengths and weldability. Although N50 is often considered for cryogenic applications, little published data exists at 4 K. Here, a full series of tests have been conducted at 295 K and 4 K, and static tensile properties of four forgings of commercially-available N50 are reported along with fatigue life, fatigue crack growth rate (FCGR), and fracture toughness data. This study makes a significant contribution to the cryogenic mechanical properties database of high strength, paramagnetic alloys with potential for superconducting magnet applications.

McRae, D. M.; Walsh, R. P.; Dalder, E. N. C.; Litherland, S.; Trosen, M.; Kuhlmann, D. J.

2014-01-01

441

The Influence of Corrosion and Cross-Section Diameter on the Mechanical Properties of B500c Steel  

NASA Astrophysics Data System (ADS)

Corrosion is a negative contributor on the structural integrity of concrete structures and leads to degradation of the mechanical properties of steel rebar. Exposure to chloride, seawater, salt and saltwater and deicing chemical environments influences the concrete-steel bond and weakens it. A considerable strength factor of the two-phase steel B500c (martensitic, ferritic-perlitic) is considered to be the outer martensitic cortex thickness, which varies according to the area of the rebar cross section. In order to evaluate the influence of corrosion and the size of the area on the mechanical properties of B500c steel, an experimental investigation was conducted on B500c ribbed steel rebar of 8, 12, 16, and 18 mm diameter, and which were artificially corroded for 10, 20, 30, 45, 60, 90, and 120 days. The laboratory tests suggest that corrosion duration and rebar cross-sectional area size had a significant impact on the strength and ductility degradation of the specimens. The tensile mechanical properties before and after corrosion indicated progressive variation and drastic drop in their values. The extended salt spray exposure enhanced the damage and created pits and notches, resulting in stress concentration points and progressive reduction of ductility and available energy. Anti-seismic design and codes that ignore the influence of the size of the cross-section area and the level of corrosion and mechanical behavior of reinforcing steel could lead to unpredictable performance during severe ground motion.

Apostolopoulos, Ch. Alk.

2009-03-01

442

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

443

Effect of ultrasonic nanocrystal surface modification on surface and fatigue properties of quenching and tempering S45C steel  

NASA Astrophysics Data System (ADS)

Ultrasonic nanocrystal surface modification (USNM) utilizing ultrasonic vibration energy is a method which induces severe plastic deformation to a material's surface and an enhanced surface layer in order to produce a nano-structured surface. In this paper, USNM was performed to enhance the surface properties of quenched and tempered S45C steel by producing a nanostructured surface layer. Various processing parameters, such as static loading (50 N, 60 N and 70 N) and processing density (34,000 mm-2 and 68,000 mm-2), were applied in the surface treatment. The microstructure, hardness and residual stress of the material were analyzed. A rotating bending fatigue test was used to investigate the fatigue properties of the enhanced surface layer. A maximum static load of about 50 N was found for S45C steel process. As the strike number increased, a deeper refined grain layer and higher compressive residual stress was produced on the material's surface. The fatigue strength can be improved from 464 Mpa to about 550 Mpa through this process. Surface cracks, formed due to a heightened processing density of 68,000 mm-2, were found on the top surface layer of the material and large processing density was the reason of the formation of cracks.

Wu, Bo; Zhang, Jianxun; Zhang, Linjie; Pyoun, Young-Shik; Murakami, Ri-ichi

2014-12-01

444

Effect of Hydrogen on Mechanical Properties of 23Co14Ni12Cr3Mo Ultrahigh Strength Steel  

NASA Astrophysics Data System (ADS)

In order to evaluate the effect of hydrogen on mechanical properties of 23Co14Ni12Cr3Mo ultrahigh strength steel, the specimens were electrochemically hydrogen charged for different times. The tensile property, fatigue fracture behavior, fatigue crack growth (FCG) behavior, and threshold stress intensity (? K th) of the samples were studied. The fracture morphology was characterized by scanning electron microscopy. It was shown that tensile strength decreases from 2300 to 2000 MPa, critical fatigue stress from 577 to 482 MPa, and ? K th from 27.4 to 14.3 MPam0.5 with the increasing hydrogen contents from 0.0001 to 0.0008 wt.%. Hydrogen enhances the FCG rate from 2.4 × 10-3 to 3.6 × 10-3 mm/cycle at ? K = 80 MPam0.5 in the hydrogen-charging range. Microscopic observation showed that the tensile fracture is a combination of overload microvoids and some intergranular regions for 0 h, and isolated areas of transgranular (TG) fracture are observed with brittle cleavage for 24-72 h. The fatigue fracture is ductile for the uncharged specimens, while the hydrogen-charged specimens show mainly brittle TG fracture. These results suggest that hydrogen degrades the fracture behavior of 23Co14Ni12Cr3Mo ultrahigh strength steel.

Liu, Jianhua; Wen, Chen; Yu, Mei; Li, Songmei

2013-12-01

445

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

446

Effect of High-Velocity Oxy-Fuel (HVOF) Thermal Spraying on Physical and Mechanical Properties of Type 316 Stainless Steel  

SciTech Connect

Data on the microstructural, physical, and mechanical characteristics of high-velocity oxygen-fuel (HVOF)-sprayed type 316 stainless steel coatings are presented and compared with properties of wrought 316 stainless steel. Coatings were prepared at three different spray particle velocities; coating characteristics are presented as a function of velocity. The coatings had relatively low porosity and oxide contents and were significantly harder than annealed, wrought 316 stainless steel. The hardness difference is primarily attributed to high dislocation densities resulting from peening imparted by high-velocity spray particles. The coating hardness increased with increasing spray particle velocity, reflecting increased peening effects. The elastic modulus of the coatings was essentially identical to wrought material. The mean coefficient of thermal expansion of as-sprayed coatings was lower than wrought material, but the expansion of annealed coatings matched the wrought behavior.

Terry C. Totemeier

2005-09-01

447

Effect of Nitrogen Content on Grain Refinement and Mechanical Properties of a Reversion-Treated Ni-Free 18Cr-12Mn Austenitic Stainless Steel  

NASA Astrophysics Data System (ADS)

Martensite reversion treatment was utilized to obtain ultrafine grain size in Fe-18Cr-12Mn-N stainless steels containing 0 to 0.44 wt pct N. This was achieved by cold rolling to 80 pct reduction followed by reversion annealing at temperatures between 973 K and 1173 K (700 °C and 900 °C) for 1 to 104 seconds. The microstructural evolution was characterized using both transmission and scanning electron microscopes, and mechanical properties were evaluated using hardness and tensile tests. The steel without nitrogen had a duplex ferritic-austenitic structure and the grain size refinement remained inefficient. The finest austenitic microstructure was achieved in the steels with 0.25 and 0.36 wt pct N following annealing at 1173 K (900 °C) for 100 seconds, resulting in average grain sizes of about 0.240 ± 0.117 and 0.217 ± 0.73 µm, respectively. Nano-size Cr2N precipitates observed in the microstructure were responsible for retarding the grain growth. The reversion mechanism was found to be diffusion controlled in the N-free steel and shear controlled in the N-containing steels. Due to a low fraction of strain-induced martensite in cold rolled condition, the 0.44 wt pct N steel displayed relatively non-uniform, micron-scale grain structure after the same reversion treatment, but it still exhibited superior mechanical properties with a yield strength of 1324 MPa, tensile strength of 1467 MPa, and total elongation of 17 pct. While the high yield strength can be attributed to strengthening by nitrogen alloying, dislocation hardening, and slight grain refinement, the moderate strain-induced martensitic transformation taking place during tensile straining was responsible for enhancement in tensile strength and elongation.

Behjati, P.; Kermanpur, A.; Najafizadeh, A.; Samaei Baghbadorani, H.; Karjalainen, L. P.; Jung, J.-G.; Lee, Y.-K.

2014-12-01

448

Basic properties of sintering dust from iron and steel plant and potassium recovery.  

PubMed

With the production of crude steel, China produces several million tons of sintering dusts which contain a great deal of valuable metals such as, K, Na, Zn, Pb. If discharged directly without adequate treatment, these elements can lead to adverse effects on the environment. Therefore, it is very necessary to determine how to separate these elements from the dust before discharge. Several physical and chemical detection methods were used to study the basic properties of sintering dust. At the same time, preliminary experiments on the recovery of the potassium resources from the sintering dust were carried out. The mean particle size of the electrostatic precipitator (ESP) dust determined by a laser granulometer was 41.468 microm. Multi-point BET and single-point BET analysis showed that the surface area of the ESP dust was 2.697 m2/g. XRD measurements detected the following phases in the ESP dust: Fe2O3, Fe3O4, KCl and NaCl, and Fe2O3, Fe3O4 and SiO2 in the water-washed dust. SEM-EDS results proved that in the ESP dust, K mostly existed in the form of KCl particles without being coated. Leaching experiments showed that the KCl in the ESP dust could be separated and recovered by water leaching and fractional crystallization. Through the recovery experiments, the yield of K-Na vaporized crystalline salt was 18.56%, in which the mass fractions of KCl, NaCl, CaSO4 and K2SO4 were about 61.03%, 13.58%, 14.03% and 9.97%, respectively. This process is technically viable and considerable in economic benefit. There was almost no secondary pollution produced in the whole recovery process. PMID:24191613

Zhan, Guang; Guo, Zhancheng

2013-06-01

449

[Stainless steels for medical instruments].  

PubMed

Both in the USSR and abroad similar types of martensitic and austenitic stainless steel are used for the manufacture of medical instruments. Martensitic steel, the cheapest and most economically alloyed, has the best combination of properties necessary for medical instruments. The analysis of the Soviet and foreign experience in using different grades of steel for the production of medical instruments demonstrates the expediency and possibility of improving the quality of martensitic steel and rolled stock, as well as that of medical instruments manufactured from these materials, by improving, the operations of the metallurgical and technological processes and by specifying more precisely the requirements for medical instruments. The possibility and expediency of using, in some technically justified cases, lower grades of alloyed steel instead of grade 12X18H9T for clamps and other instruments made of stainless steel, as well as highly corrosive grades of steel for microinstruments, have been established. PMID:7300626

Feofilov, R N

1981-01-01

450

Microstructure-property relationships in cold-rolled motor lamination steel  

NASA Astrophysics Data System (ADS)

The dependence of magnetic properties such as core loss and peak permeability on the temper rolling process has been studied in a semi-processed, cold rolled magnetic lamination (CRML) steel. The results indicate that temper rolling parameters such as temper mill extension and roll roughness have a significant influence on the magnetic properties. Material processed with high temper mill extension and smooth work rolls shows a sharper texture, which results in highly anisotropic peak permeability values between the rolling direction and the transverse direction. Texture analy