应变速率对高氮奥氏体不锈钢塑性流变行为的影响

研究了室温拉伸时应变速率对高氮奥氏体不锈钢18%Cr-18%Mn-0.65%N力学性能和塑性流变行为的影响。结果表明,随应变速率的升高,试验钢的屈服强度Rp0.2升高,而抗拉强度Rm及塑性略有降低;在各应变速率下,试验钢的塑性流变行为均可以用Ludwigson模型进行描述;应变速率的升高对试验钢流变方程参数的影响如下：1）强度系数K1、应变硬化指数n1和n2减小,试验钢的加工硬化能力降低;2）真实屈服强度TYS降低;3）瞬变应变εL减小,表明升高应变速率能够促进位错多系滑移和交滑移。

Effect of Strain Rate on Plastic Flow Behaviors of High Nitrogen Austenitic Stainless Steel

This article studied the effects of strain rates on the mechanical properties and plastic flow behaviors of high nitrogen austenitic stainless steel 18%Cr-18%Mn-0.63N in room temperature tension. The results showed that with the strain rate increased,the yield strength Rp0.2 of the test steel increased but the tensile strength Rm and plasticity decreased slightly. Under every strain rate,the plastic flow behavior of the test steel was modeled by Ludwigson model all. The effect of the strain rate increase on the plastic flow function parameters was as follows： 1）The strength coefficient K1, strain hardening exponent n1 and n2 decreased, which means the decrease of work hardening ability of test steel. 2）The true yield strength decreased. 3）Transient strain εL decreased, indicates that the increase of strain rate promote multi slip and cross slip of dislocation.