奥氏体不锈钢塑性变形行为及冲压成型性研究

Study on Plastic Deformation Behavior and Stamping Formability of Austenitic Stainless Steel

采用单向拉伸试验和冲压成型试验对奥氏体不锈钢304L进行研究,利用电子显微镜观察拉伸后的微观组织,分析它的塑性变形以及冲压成型行为。结果表明:304L具有较高屈服强度和断后伸长率,通过拟合计算得到,应变硬化系数为160.77 MPa,应变硬化指数为0.45;拉伸过程中,304L的主要转变机制为γ→α,其断裂模式为脆性断裂及韧性断裂的混合断裂模式;通过冲压成型试验,获得304L的平均塑性应变比r为0.977,应变硬化指数n值为0.32,杯突值(IE)为12.78 mm。

The austenitic stainless steel 304L was studied by unidirectional tensile test and stamping forming test.The microstructure after stretching was observed by electron microscope.The results show that 304L has high yield strength and elongation after fracture.Through fitting calculation,the strain hardening coefficient K and strain hardening index are 160.77 MPa and 0.45 respectively.During the tensile process,the main transformation mechanism of plastic deformation of 304L isγ→α.The fracture mode is a mixed fracture mode of brittle fracture and ductile fracture.Through the stamping test,the average plastic strain ratio r of 304L is 0.977,the strain hardening index n is0.32,and the cupping value IE is 12.78 mm.