基于压痕应变的不锈钢材料拉伸性能参数计算方法

Calculation of Tensile Property Parameters of Stainless Steel Materials Based on Indentation Strain

建立连续球压痕试验三维有限元模型,通过单一变量法模拟了残余压痕应变与不同材料拉伸性能参数(弹性模量90~210 GPa、屈服强度180~300 MPa、应变硬化指数0.1~0.3)的关系;在125组拉伸性能参数组合下进行连续球压痕试验有限元模拟,得到基于残余压痕应变的材料拉伸性能参数计算公式并进行了试验验证。结果表明:残余压痕应变分别与弹性模量和屈服强度存在对数线性关系,其对数与应变硬化指数之间存在幂律关系;将连续球压痕试验测得的316L不锈钢的残余压痕应变代入材料拉伸性能参数计算公式,反演计算得到的弹性模量、屈服强度和应变硬化指数与拉伸试验结果的相对误差分别为1.50%,1.57%,0.22%,说明基于残余压痕应变的不锈钢材料拉伸性能参数计算方法可以满足工程需要。

A three-dimensional finite element model for continuous ball indentation tests was established,and the relationship between residual indentation strains and different material tensile property parameters(elastic modulus of 90-210 GPa,yield strength of 180-300 MPa,strain hardening exponent of 0.1-0.3)was simulated by a single variable method.Finite element simulation of continuous ball indentation tests was performed under 125 sets of material tensile property parameter combinations,and formulas for calculating material tensile property parameters based on residual indentation strains were obtained and verified experimentally.The results show that there was a log-linear relationship between the residual indentation strain and the modulus of elasticity and yield strength,respectively,and a power-law relationship between the residual indentation strain logarithm and the strain hardening exponent.The residual indentation strains of 316 L stainless steel measured by the continuous ball indentation test were substituted into the material tensile property parameter calculation formula,and the relative errors between the elastic modulus,yield strength,and strain hardening exponent obtained by inversion and the tensile test results were 1.50%,1.57%,and 0.22%,respectively,indicating that the stainless steel material tensile property parameter calculation method based on the residual indentation strain could meet the engineering needs.