Rate effects on transformation kinetics in a metastable austenitic stainless steel

• Published in: Procedia engineering Vol. 207; pp. 2006 - 2011
• Main Authors: Alturk, Rakan, Luecke, William E., Mates, Steven, Araujo, A., Raghavan, K.S., Abu-Farha, Fadi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 2017
• Subjects: 201 Stainless Steel; Austenite; High Rate Deformation; Kolsky Bar; Strain Rate Sensitivity; Transformation Kinetics; Transformation Kinetics; 201 Stainless Steel; Strain Rate Sensitivity; High Rate Deformation; Austenite; Kolsky Bar
• ISSN: 1877-7058; 1877-7058
• DOI: 10.1016/j.proeng.2017.10.1059

In this study, the effects of strain rate on the mechanical properties and the strain-induced austenite-to-martensite transformation in type 201 austenitic stainless steel (SS201) were investigated. This grade was selected as a low-cost stainless steel with good lightweighting potential for automotive applications. The material was tested in tension at a quasi-static rate (5x10-2 s-1), two low-intermediate rates (100 s-1 and 101 s-1), and a high rate (5x102 s-1). 3D digital image correlation was used to enable accurate strain measurements during mechanical testing. Magnetic induction and X-ray diffraction were used ex-situ of deformation to measure the volume fraction of martensite formed at each strain rate, for different plastic strain levels. The effects of strain rate on deformation-induced martensite formation and on the stress/strain behavior was determined in this study, and was compared to results reported in the literature for 300 series austenitic stainless steels. The results show a favourable response for the SS201, which exhibits a substantial increase in strength and energy absorption at high rates without compromising tensile ductility.