scholarly journals Dynamic tensile tests on ferritic and austenitic steels with improved testing and measuring technique

1994 ◽  
Vol 04 (C8) ◽  
pp. C8-141-C8-146 ◽  
Author(s):  
K. Kussmaul ◽  
M. Schuele
Keyword(s):  
Tensile Tests ◽  
Austenitic Steels ◽  
Measuring Technique ◽  
Dynamic Tensile Tests

scholarly journals Stacking Fault Energy in Relation to Hydrogen Environment Embrittlement of Metastable Austenitic Stainless CrNi-Steels

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1170
Author(s):  
Robert Fussik ◽  
Gero Egels ◽  
Werner Theisen ◽  
Sebastian Weber
Keyword(s):  
Phase Transformation ◽  
Intermediate Stage ◽  
Tensile Tests ◽  
Stacking Fault ◽  
Hydrogen Gas ◽  
Stacking Fault Energy ◽  
Austenitic Steels ◽  
Aisi 304L ◽  
Hydrogen Environment ◽  
Gas Atmosphere

Metastable austenitic steels react to plastic deformation with a thermally and/or mechanically induced martensitic phase transformation. The martensitic transformation to α’-martensite can take place directly or indirectly via the intermediate stage of ε-martensite from the single-phase austenite. This effect is influenced by the stacking fault energy (SFE) of austenitic steels. An SFE < 20 mJ/m2 is known to promote indirect conversion, while an SFE > 20 mJ/m2 promotes the direct conversion of austenite into α’-martensite. This relationship has thus far not been considered in relation to the hydrogen environment embrittlement (HEE) of metastable austenitic CrNi steels. To gain new insights into HEE under consideration of the SFE and martensite formation of metastable CrNi steels, tensile tests were carried out in this study at room temperature in an air environment and in a hydrogen gas atmosphere with a pressure of p = 10 MPa. These tests were conducted on a conventionally produced alloy AISI 304L and a laboratory-scale modification of this alloy. In terms of metal physics, the steels under consideration differed in the value of the experimentally determined SFE. The SFE of the AISI 304L was 22.7 ± 0.8 mJ/m2 and the SFE of the 304 mod alloy was 18.7 ± 0.4 mJ/m2. The tensile specimens tested in air revealed a direct γàα’ conversion for AISI 304L and an indirect γàεàα’ conversion for 304mod. From the results it could be deduced that the indirect phase transformation is responsible for a significant increase in the content of deformation-induced α’-martensite due to a reduction of the SFE value below 20 mJ/m2 in hydrogen gas atmosphere.

The Change of the Structure and Mechanical Properties of the Austenitic Steels after Exposure at the Critical Temperature

2017 ◽  
Vol 891 ◽  
pp. 330-334 ◽  
Author(s):  
Šárka Stejskalová ◽  
Ladislav Kander ◽  
Šárka Hermanová
Keyword(s):  
Mechanical Properties ◽  
Critical Temperature ◽  
Thermal Exposure ◽  
Tensile Tests ◽  
Austenitic Steels ◽  
Small Punch Test ◽  
Bend Radius ◽  
Small Punch ◽  
Σ Phase ◽  
Punch Test

The paper deals with the change of the structure and mechanical properties of the austenitic steels after the exposure at the critical temperature. The effects of the bend radius of tubes including effect of solution annealing on the mechanical properties and the structure were studied. The mechanical properties were studied using small punch test (SPT) and miniaturized tensile tests. From the results can be concluded that the mechanical properties and the structure have been influenced due to one year exposure at the working temperature significantly. Various amounts of σ-phase were found in the pulled part of the bend side of the tubes even after only thermal exposure without any loading. The effect of the heat treatment and the bend radius on the mechanical properties and the structure was also evident. Drop in fracture energy due to the presence of the σ-phase in the structure was clearly detected from force - displacement record of the small punch test. Keywords: Austenitic steels, bends, σ-phase, small punch test

Embrittlement of a High Manganese TWIP Steel in the Presence of Liquid Zinc

2012 ◽  
Vol 706-709 ◽  
pp. 2041-2046 ◽  
Author(s):  
Coline Beal ◽  
Xavier Kleber ◽  
Damien Fabrègue ◽  
Mohamed Bouzekri
Keyword(s):  
Strain Rate ◽  
Twip Steel ◽  
Deformation Mode ◽  
Tensile Tests ◽  
Limited Range ◽  
Austenitic Steels ◽  
Liquid Zinc ◽  
High Manganese ◽  
Environmental Requirements ◽  
Classical Mechanism

In the past decade, new steels have been developed for the automotive industry in the framework of environmental requirements. Among them, high manganese austenitic steels combining exceptional properties of strength and ductility are particularly promising. These exceptional properties stem from a fully austenitic structure at room temperature and a twinning deformation mode in addition to the classical mechanism of dislocation gliding, known as the TWinning Induced Plasticity (TWIP) effect. In this study, the cracking resistance of the Fe22Mn0.6C TWIP steel was investigated in relation to the liquid metal embrittlement (LME) phenomenon. Indeed, liquid zinc has been found to have an embrittling effect on such steels. Electro-galvanized specimens were subjected to hot tensile tests using Gleeble® thermo-mechanical simulator. The influence of different parameters such as temperature and strain rate on embrittlement was studied. The results show that this steel can be embrittled by liquid zinc within a limited range of temperature depending on strain rate. A critical stress for cracking has been defined for each embrittlement condition.

scholarly journals UJI TARIK DINAMIS BATANG SAMPEL ALUMINUM 6061T8 DENGAN METODA FOTOGRAFIS = DYNAMIC TEST PULL ROD 6061T8 ALUMINUM SAMPLES WITH PHOTOGRAPHICALLY METHODS

2015 ◽  
Vol 9 (3) ◽  
pp. 147-156
Author(s):  
Sahlan .
Keyword(s):  
Strain Rate ◽  
Work Hardening ◽  
Dynamic Test ◽  
Tensile Tests ◽  
Model System ◽  
Rotating Drum ◽  
Led Light ◽  
Dynamic Tensile Tests

The model system of a photographic using light-emiting dioda (LED) iluminator and a 35-mm rotating drum camera has ben developed for diagnosis of dynamic-tensile tests conducted with split tension bar. Back-lit photographs of deforming tensile samples are obtained at rates up to 50 kHz that test were conducted with 6061T8 aluminum, since this material is relatively well characterized and relatively insentive to strain rate and work hardening. The LED exposures are precisely time corrected with the conventional bar-straingage records. The system can be used to extended the measurement of stressstrain-gage curves beyond the onset of plastic instability. ABSTRAKSistem pemodelan fotografis yang menggunakan iluminator LED (Light Emiting Dioda) dan kamera film 35 mm di coba untuk digunakan mendiagnosis uji tarik dinamis batang uji. Pengulangan pada uji fotografis pada beberapa bentuk sampel uji tarik aluminum 6061T8 dengan kecepatan sampai dengan 50 kHz , yang mana material ini relatif memiliki karakteristik yang sangat bagus dan relatif lebih tahan terhadap kekuatan regangan rata-ratamya dan tingkat kekerasan yang tinggi. Pencahayaan LED pada saat yang tepat dapat terkoreksi hasilnya dengan pencatatan pengukuran batang sampel uji konvensional. Pemakaian ini dapat dipergunakan lebih luas untuk pengukuran kurva tegangan-regangan terhadap deformasi plastis yang labil.

Numerical analysis of interruption process of dynamic tensile tests using a Hopkinson bar

2003 ◽  
Vol 110 ◽  
pp. 565-570 ◽  
Author(s):  
R. González Lezcano ◽  
Y. E. Essa ◽  
J. L. Pérez-Castellanos
Keyword(s):  
Numerical Analysis ◽  
Hopkinson Bar ◽  
Tensile Tests ◽  
Dynamic Tensile Tests
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