Room-temperature blue brittleness of Fe-Mn-C austenitic steels

2017 ◽  
Vol 141 ◽  
pp. 20-23 ◽  
Author(s):  
Motomichi Koyama ◽  
Yusaku Shimomura ◽  
Aya Chiba ◽  
Eiji Akiyama ◽  
Kaneaki Tsuzaki
Keyword(s):  
Room Temperature ◽  
Austenitic Steels ◽  
Blue Brittleness

Crack Path and Liquid Metal Embrittlement Specificity of Austenitic Steels in Mercury at Room Temperature

2021 ◽  
Author(s):  
Thierry Auger ◽  
Bassem Barkia ◽  
Eva Héripré ◽  
Vincent Michel ◽  
Denis Mutel ◽  
...  
Keyword(s):  
Liquid Metal ◽  
Room Temperature ◽  
Crack Path ◽  
Liquid Metal Embrittlement ◽  
Austenitic Steels

Fatigue Behavior of High Manganese TWIP Steels and of Low Alloy Q&P Steels for Car-Body Applications

2014 ◽  
Vol 783-786 ◽  
pp. 713-720
Author(s):  
Paolo Matteis ◽  
Giorgio Scavino ◽  
R. Sesana ◽  
F. D’Aiuto ◽  
Donato Firrao
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Fatigue Behavior ◽  
Austenitic Steels ◽  
Fracture Mechanisms ◽  
High Manganese ◽  
Cold Forming ◽  
Austenitic Structure ◽  
Plasticity Effect ◽  
Twip Steels

The automotive TWIP steels are high-Mn austenitic steels, with a relevant C content, which exhibit a promising combination of strength and toughness, arising from the ductile austenitic structure, which is strengthened by C, and from the TWIP (TWinning Induced Plasticity) effect. The microstructure of the low-alloy Q&P steels consists of martensite and austenite and is obtained by the Quenching and Partitioning (Q&P) heat treatment, which consists of: austenitizing; quenching to the Tqtemperature, comprised between Msand Mf; soaking at the Tppartitioning temperature (Tpbeing equal to or slightly higher than Tq) to allow carbon to diffuse from martensite to austenite; and quenching to room temperature. The fatigue behavior of these steels is examined both in the as-fabricated condition and after pre-straining and welding operations, which are representative of the cold forming and assembling operations performed to fabricate the car-bodies. Moreover, the microscopic fracture mechanisms are assessed by means of fractographic examinations.

scholarly journals Effect of Supercritical CO2 on Steel Ductility at 450°-650°C

2021 ◽  
Author(s):  
Bruce A. Pint ◽  
Rishi Pillai ◽  
James R. Keiser
Keyword(s):  
Tensile Properties ◽  
Supercritical Co2 ◽  
Room Temperature ◽  
Reaction Rates ◽  
Significant Loss ◽  
Austenitic Steels ◽  
Maximum Temperature ◽  
Clear Correlation ◽  
Temperature Capability ◽  
Product Thickness

Abstract The compatibility of ferritic-martensitic (FM) and conventional and advanced austenitic steels with supercritical CO2 (sCO2) is being explored at 450°–650°C to determine their maximum temperature capability. In addition to measuring reaction kinetics and reaction product thickness, bulk carbon content and post-exposure room temperature tensile properties were assessed by exposing both alloy coupons and 25 mm long dogbone tensile specimens. After 1–2 kh exposures in 300 bar research grade (RG) sCO2, ∼9 and 12%Cr FM steels had similar behavior under these conditions. Consistent with the literature, higher Cr and Ni contents in alloy 316H provided lower reaction rates at 450° and 550°C, but limited benefit at 650°C with similar degradation of tensile properties and C ingress observed. An advanced austenitic Nb-modified 20Cr-25Ni alloy 709 provided the best compatibility even at 650°C with no C uptake detected after 1 kh and no significant loss in room temperature tensile properties after exposure. A clear correlation was observed under these conditions between the formation of a thin, protective Cr-rich oxide scale and the prevention of C ingress and tensile property degradation at 650°C.

The Tensile Ductility of Austenitic Steels in Air and Hydrogen

1977 ◽  
Vol 99 (2) ◽  
pp. 153-158 ◽  
Author(s):  
T. L. Capeletti ◽  
M. R. Louthan
Keyword(s):  
Stainless Steels ◽  
Room Temperature ◽  
Tensile Ductility ◽  
Austenitic Stainless Steels ◽  
Empirical Correlation ◽  
Interfacial Stress ◽  
Austenitic Steels ◽  
Steel Strength ◽  
Reduction In Area ◽  
Extensive Plastic Deformation

An empirical correlation of yield strength with reduction-in-area at fracture was demonstrated for austenitic stainless steel. The correlation is consistent with an existing fracture model that involves microvoid nucleation at isolated inclusions. Hydrogen effects on tensile ductility are also consistent with this model, if one assumes that hydrogen is transported by glide dislocations and that localized hydrogen accumulations lower the stress necessary to initiate fracture at particle-matrix interfaces. Smooth-bar tensile specimens of fourteen austenitic stainless steels were tested at room temperature in air, in 69-M Pa He, and in 69-M Pa H2. Macroscopic reductions-in-area at fracture varied between 12 and 82 percent, and yield strengths were between 179 and 1069 MN/m2. The resulting empirical correlation suggests that the ductility of austenitic stainless steels is limited by the interfacial stress required for microvoid nucleation and coalescence. For low strength steels, the required interfacial stress is reached only after extensive plastic deformation. However, as steel strength is increased, fracture occurs at lower strains.

On the transitions of deformation modes of fully austenitic steels at room temperature

2010 ◽  
Vol 16 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Kyung-Tae Park ◽  
Gyosung Kim ◽  
Sung Kyu Kim ◽  
Sang Woo Lee ◽  
Si Woo Hwang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Austenitic Steels ◽  
Deformation Modes

Fatigue Design Criteria for Pressure Vessel Alloys

1977 ◽  
Vol 99 (4) ◽  
pp. 584-592 ◽  
Author(s):  
C. E. Jaske ◽  
W. J. O’Donnell
Keyword(s):  
Pressure Vessel ◽  
Room Temperature ◽  
High Cycle Fatigue ◽  
Austenitic Steels ◽  
Design Criteria ◽  
Fatigue Design ◽  
Alloy 800 ◽  
Pressure Vessel Steels ◽  
Fatigue Data ◽  
Mean Stresses

Fatigue design criteria for pressure vessel steels are developed herein based on analysis of available material data between room temperature and 427 C (800 F). Strain-controlled low-cycle and high-cycle fatigue data for austenitic steels, alloy 800, alloy 600, and alloy 718 were evaluated. The effects of mean stresses were considered and design curves were proposed for use in Sections III and VIII of the ASME Boiler and Pressure Vessel Code.

A Study of the Structure and Properties of Austenitic Metastable Steels under Strain

2018 ◽  
Vol 284 ◽  
pp. 207-211
Author(s):  
N. Ozerets ◽  
Valentina A. Sharapova ◽  
A. Levina ◽  
T. Mal'tseva ◽  
M. Pavlov
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Negative Temperature ◽  
Strength Properties ◽  
Austenitic Steels ◽  
Structure And Properties ◽  
Corrosion Resistant ◽  
Equal Degree ◽  
Negative Temperatures ◽  
Strain Induced Martensite

The structure and mechanical properties of the corrosion-resistant metastable austenitic steels 03Kh14N11К5М2YuТ and 03Kh14N11КМ2YuТ have been investigated. The steels have been deformed by tagging them at room and negative temperatures. It has been established that the amount of martensite and the strength properties are higher at a negative temperature than at room temperature with an equal degree of strain. The investigated austenitic steels are strain-metastable. The higher the strain degree and the lower the deformation temperature, the greater the amount of strain-induced martensite and, correspondingly, the higher the strength properties. Martensite is not observed upon cooling to the temperature of liquid nitrogen.

Fatigue Behaviour of Carbide Precipitation Hardened Austenitic Steels

2015 ◽  
Vol 226 ◽  
pp. 69-74
Author(s):  
Kazimierz J. Ducki ◽  
Marek Cieśla ◽  
Grzegorz Junak ◽  
Lilianna Wojtynek
Keyword(s):  
Heat Treatment ◽  
Room Temperature ◽  
Low Cycle Fatigue ◽  
Fatigue Behaviour ◽  
Fatigue Tests ◽  
Austenitic Steels ◽  
Cycle Fatigue ◽  
Softening Effect ◽  
Fatigue Durability ◽  
Increased Temperature

The paper presents the results of investigations of the microstructure and fatigue behaviour of two newly invented Cr-Ni and Cr-Ni-Mn austenitic steels of 13/13 and 12/8/8 type strengthened through carbide particle precipitation. The specimens of the investigated steels were subjected to tests after heat treatment, i.e. solution heat treatment (1200°C/0.5 h/water) and aged at a temperature of 700°C for 12 h, with cooling in air. The heat treated specimens were then subjected to low-cycle fatigue tests (LCF), carried out at room temperature and at an increased temperature of 600°C. Diagrams of fatigue characteristics of the investigated steels at room temperature as well as at elevated temperature have been worked up. It has been found that during low-cycle fatigue tests, at both temperatures, the investigated austenitic steels indicated a fatigue softening effect. The results of LCF at room temperature showed that the fatigue durability (Nt) of both austenitic steels is located in the range 0.8÷1.3×103 cycles. The results of low-cycle fatigue tests at an increased temperature 600°C indicated that the fatigue durability of the investigated steel was lower, and is located in the range Nt = 0.5÷0.6×103 cycles. It has been pointed out that the investigated austenitic steels are characterized by a stability of structure in conditions of cyclic fatigue.

Stress Corrosion Cracking in Fe-Mn-Cr Alloys

CORROSION ◽  
1976 ◽  
Vol 32 (5) ◽  
pp. 187-190 ◽  
Author(s):  
MARKUS O. SPEIDEL
Keyword(s):  
Stress Corrosion ◽  
Stress Corrosion Cracking ◽  
Crack Velocity ◽  
Room Temperature ◽  
High Strength ◽  
Corrosion Cracking ◽  
Austenitic Steels ◽  
Distilled Water ◽  
Material Environment ◽  
Stress Corrosion Resistance

Abstract The stress corrosion resistance of austenitic chromium-maganese steels has been measured using fracture mechanics techniques. The resulting crack velocity-stress intensity curves resemble those observed with other material-environment combinations. High strength, nonmagnetic austenitic steels of the 18% Mn-5% Cr-0.5% C variety exhibit both intergranular and transgranular stress corrosion cracking (SCC) in distilled water at room temperature. Important mechanical and environmental effects on stress corrosion crack growth are measured and discussed.

Evolution of Special Grain Boundaries in Austenitic Steels

2007 ◽  
Vol 537-538 ◽  
pp. 355-362 ◽  
Author(s):  
Z. Gaál ◽  
Péter János Szabó
Keyword(s):  
Stainless Steel ◽  
Room Temperature ◽  
Electron Back Scatter Diffraction ◽  
Austenitic Steels ◽  
Boundary Structure ◽  
Cold Forming ◽  
Grain Boundary Structure ◽  
Different Types ◽  
Temperature Electron ◽  
Cold Rolled

Three different types of austenitic stainless steel (SUS 304, SUS 304L and SUS 316) samples were cold formed in order to investigate the effect of cold forming on the grain boundary structure of the material. SUS 304L and SUS 316 samples were cold rolled, SUS 304 samples were tensile loaded in different manner at room temperature. Electron back scatter diffraction measurements have been carried out in order to obtain information about the boundaries of the treated specimen. The measurements showed that the frequency of the special Σ3n type CSLboundaries was significantly decreased by increasing the deformation of the samples.

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