为了准确仿真高强钢板热冲压成形过程，获得高强钢高温下的材料本构关系模型，利用Gleeble3500热模拟试验机在不同温度和应变速率下对不同厚度的高强钢B1500HS钢板进行了单向拉伸试验，获得各种工艺条件下的应力－应变曲线，并基于变形抗力数学模型，引入板材厚度参数，通过最小二乘法进行数据拟合获得高强钢TRB高温下的材料本构关系。利用试验结果对本构关系模型进行的拟合验证表明，拟合程度较好，说明建立的材料本构关系能很好地描述高强钢TRB在高温下的应力－应变关系。%In order to simulate the hot stamping process of high strength steel tailor rolled blank (TRB), a proper constitutive behavior needs to be determined to describe the relationship between the thermodynamic properties of high strength steel and strain rates, deformations and temperatures. Then the material model of high strength steel TRB can be established in the hot deformation process. The stress⁃strain curve at different temperatures and strain rates can be obtained by the isothermal tensile tests, then the constitutive relationship model of high strength steel TRB at elevated temperature can be established by the mathematical method. At the present, it is still the most reliable techniques with the highest precision. Using Gleeble3500 thermal simulation testing machine, tensile tests were carried out for B1500HS high strength steel blank in different thicknesses at different temperatures and strain rates. Then the stress⁃strain curves were obtained with various process parameters, the constitutive relationship of high strength steel TRB was derived by fitting the test data. In addition, other test results were fed back to validate the constitutive model and it showed that the test and fitted results matched very well. Therefore the constitutive relation can be used to describe the high strength steel TRB stress⁃strain relationship, which lays a foundation for numerical simulation of the hot stamping process for high strength steel TRB in the future.
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