Alturk Rakan, Luecke William E, Mates Steven, Araujo A, Raghavan K S, Abu-Farha Fadi
Clemson University - International Center for Automotive Research (CU-ICAR), Greenville, SC 29607, USA.
National Institute of Standards and Technology (NIST), Gaithersburg, MD 20899, USA.
Procedia Eng. 2017;207. doi: https://doi.org/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 (5×10 s), two low-intermediate rates (10 s and 10 s), and a high rate (5×10 s). 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.
在本研究中，研究了应变速率对201型奥氏体不锈钢（SS201）力学性能以及应变诱导奥氏体向马氏体转变的影响。该钢种被选为一种低成本不锈钢，在汽车应用中具有良好的轻量化潜力。材料在准静态速率（5×10⁻³ s⁻¹）、两个低中速率（10⁻² s⁻¹和10⁻¹ s⁻¹）以及高速率（5×10¹ s⁻¹）下进行拉伸试验。使用三维数字图像相关技术以便在力学测试过程中进行精确的应变测量。在变形后使用磁感应和X射线衍射来测量在不同塑性应变水平下，每种应变速率下形成的马氏体体积分数。本研究确定了应变速率对变形诱导马氏体形成以及应力/应变行为的影响，并与文献中报道的300系列奥氏体不锈钢的结果进行了比较。结果表明SS201具有良好的响应，在高速率下强度和能量吸收大幅增加，而不影响拉伸延展性。
