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Strain‐Induced Martensite Formation and Mechanical Properties of Fe–19Cr–4Ni–3Mn–0.15N–0.15C Austenitic Stainless Steel at Cryogenic Temperature
Author(s) -
Alsultan Saba,
Quitzke Caroline,
Cheng Zhaoyang,
Krüger Lutz,
Volkova Olena,
Wendler Marco
Publication year - 2021
Publication title -
steel research international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.603
H-Index - 49
eISSN - 1869-344X
pISSN - 1611-3683
DOI - 10.1002/srin.202000611
Subject(s) - materials science , martensite , austenite , volume fraction , deformation (meteorology) , austenitic stainless steel , metallurgy , ultimate tensile strength , tensile testing , plasticity , composite material , strain rate , atmospheric temperature range , work hardening , thermodynamics , microstructure , corrosion , physics
Herein, considerable insight is provided into the evolution of strain‐induced martensite and mechanical properties of Fe–19Cr–4Ni–3Mn–0.15N–0.15C wt% austenitic stainless steel (in short Cr19NC15.15) during deformation at room temperature and cryogenic temperatures. In situ magnetic measurements of the martensite evolution during tensile tests at various temperatures are conducted. The triggering stressσ trigg. γ → α ′required for strain‐induced martensite formation is determined at the minimum in the strain hardening curve. It is found that with reducing deformation temperature in the range from 0 to –20 °Cσ trigg. γ → α ′slightly decreases, whereas the triggering stressσ trigg. γ → α ′increases with further reduction of deformation temperature to −70 °C. The relation between the formed α′‐martensite fraction and the strain applied during tensile test is established. The results demonstrate that a reduced deformation temperature from room temperature (RT) to −70 °C significantly enhances the transformation rate and the total volume fraction of strain‐induced α′‐martensite. The yield and tensile strength increase whereas elongation continuously decreases due to an increasing α′‐martensite volume fraction with decreasing tensile test temperature. The α′‐martensite formation kinetic follows Olson and Cohen's model and are in good agreement between the in situ experiment and theoretical calculations.