Effect of Strain-Induced Martensitic Transformation on Coaxing Effect of Austenitic Stainless Steels

The effects of martensitic transformation on the coaxing behavior were studied in austenitic stainless steels. The materials used were austenitic stainless steels, type 304 and 316. Conventional fatigue tests and stress-incremental fatigue tests were performed using specimens subjected to several tensile prestrains from 5% to 60%. Under conventional tests, the fatigue strengths of both steels increased with increasing prestrain. Under stress-incremental tests, 304 steel showed a marked coaxing effect, where the failure stress significantly increased irrespective of prestrain level. On the other hand, the coaxing effect in 316 steel decreased with increasing prestrain up to 15%, where the failure stresses were nearly the same. Above this prestrain level, the coaxing effect increased with increasing prestrain. In 304 steel, the coaxing effect is primarily dominated by work hardening at low prestrains, while the effect of strain-induced martensitic transformation increases with increasing prestrain. The coaxing effect in 316 steel is dominated by both work hardening and strain aging at low prestrains, but strain-induced martensitic transformation could play a significant role at high prestrains.

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The Effect of Boron on the Corrosion Resistance of Austenitic Stainless Steels

CORROSION ◽

10.5006/0010-9312-33.11.408 ◽

1977 ◽

Vol 33 (11) ◽

pp. 408-417 ◽

Cited By ~ 15

Author(s):

F. P. A. ROBINSON ◽

W. G. SCURR

Keyword(s):

Corrosion Resistance ◽

Stainless Steels ◽

Intergranular Corrosion ◽

Detrimental Effect ◽

Austenitic Stainless Steels ◽

The Other ◽

Beneficial Effects ◽

Identical Series ◽

Type 304 ◽

Intergranular Corrosion Resistance

Abstract Two Type 304 stainless steels, one boron free and the other containing 4 ppm boron were investigated. Both steels were subjected to an identical series of corrosion tests and the results compared with one another. It was found (1) Boron had no detrimental effect on the potentiostatic characteristics, intergranular corrosion “resistance and pitting resistance of the steels in the “as-received” condition; (2) boron in solid solution had no detrimental effect on the potentiostatic characteristics and intergranular corrosion resistance of the steel, while boron in solution had a beneficial effect on the pitting resistance of the steel, and (3) boron retarded Cr23C6 precipitation and thus boron had marked beneficial effects on the intergranular corrosion resistance of the steels in a sensitized condition. In addition the potentiostatic characteristics and pitting resistance of such steels were improved slightly by the presence of boron.

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Fatigue Properties of Austenitic Stainless Steels with Different Nitrogen

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.261-263.1215 ◽

2004 ◽

Vol 261-263 ◽

pp. 1215-1220 ◽

Cited By ~ 1

Author(s):

Nobusuke Hattori ◽

S. Nishida

Keyword(s):

Fatigue Strength ◽

Stainless Steels ◽

Stress Amplitude ◽

Austenitic Stainless Steels ◽

Fatigue Tests ◽

The Other ◽

Fatigue Properties ◽

Transformation Ratio ◽

Other Hand ◽

Knee Point

The fatigue properties of austenitic stainless steels become inevitably important when using in structural materials. The authors have performed fatigue tests to investigate the effect of nitrogen content on fatigue properties of typical austenitic stainless steels (SUS304) and two kinds of nitrogen-contained SUS304 (SUS304N and YUS170). The main results obtained in this study are as follows; (1) The knee point in S-N curves exists for SUS304 and SUS304N, but does not exist for YUS170. (2) The fatigue limit of SUS304N is higher than that of SUS304. On the other hand, the fatigue strength by 107 cycles of YUS170 is lower than those of SUS304 and SUS304N. (3) For SUS304, the transformation ratio increases with increase in stress amplitude. On the other hand, the transformation ratio of SUS304N is very small and that of YUS170 remains essentially zero.

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Strain-induced martensite effects on transgranular carbide precipitation in type 304 stainless steels

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087331 ◽

1991 ◽

Vol 49 ◽

pp. 604-605

Author(s):

A.H. Advani ◽

L.E. Murr ◽

D. Matlock

Keyword(s):

Heat Treatment ◽

Grain Boundary ◽

Stress Corrosion Cracking ◽

Stainless Steels ◽

Deformation Twin ◽

Austenitic Stainless Steels ◽

Carbide Precipitation ◽

Strain Induced Martensite ◽

Type 304

Thermomechanically induced strain is a key variable producing accelerated carbide precipitation, sensitization and stress corrosion cracking in austenitic stainless steels (SS). Recent work has indicated that higher levels of strain (above 20%) also produce transgranular (TG) carbide precipitation and corrosion simultaneous with the grain boundary phenomenon in 316 SS. Transgranular precipitates were noted to form primarily on deformation twin-fault planes and their intersections in 316 SS.Briant has indicated that TG precipitation in 316 SS is significantly different from 304 SS due to the formation of strain-induced martensite on 304 SS, though an understanding of the role of martensite on the process has not been developed. This study is concerned with evaluating the effects of strain and strain-induced martensite on TG carbide precipitation in 304 SS. The study was performed on samples of a 0.051%C-304 SS deformed to 33% followed by heat treatment at 670°C for 1 h.

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CARPENTER STAINLESS 304+B

Alloy Digest ◽

10.31399/asm.ad.ss0121 ◽

1961 ◽

Vol 10 (9) ◽

Keyword(s):

Fracture Toughness ◽

Cross Section ◽

Stainless Steels ◽

Austenitic Stainless Steels ◽

Heat Treating ◽

Neutron Absorption ◽

Absorption Cross ◽

Type 304 ◽

Conventional Type ◽

Neutron Absorption Cross Section

Abstract Carpenter Stainless 304+B is similar to conventional Type 304 with the addition of boron to give it a much higher thermal neutron absorption cross-section than other austenitic stainless steels. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: SS-121. Producer or source: Carpenter.

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Effect of Pre-Strain and Roller Working on Torsional Fatigue Properties of a Structural Steel

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.295-297.2227 ◽

2011 ◽

Vol 295-297 ◽

pp. 2227-2230

Author(s):

Cong Ling Zhou

Keyword(s):

Residual Stress ◽

Fatigue Limit ◽

Work Hardening ◽

Compressive Residual Stress ◽

Strain Ratio ◽

Fatigue Tests ◽

The Other ◽

Fatigue Properties ◽

Torsional Fatigue ◽

Stress Work

In this study, fatigue tests have been performed using two kinds of specimens made of 25 steel. One is pre-strained specimen with pre-strain ratio changing from 2% to 8% by tension, the other is roller worked with deformation of 0.5 mm and 1.0 mm in diameter direction. In the case of pre-strained specimen, the fatigue limit increases according to increase of tensile pre-strain, the fatigue limit of 8% pre-strained specimen is 25% higher than that of non-pre-strained one; in the case of roller worked specimen, the fatigue limit of R05 and R10 is 126% and 143% to that of non-roller worked specimen, respectively. These remarkable improvements of fatigue limit would be caused by the existence of compressive residual stress, work-hardening and the elongated microscopic structures.

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