无缝钢管张减成形的高精度有限元模型及实验验证

Visco-Elastic Plastic Finite Element Model of Stretch-Reducing Forming of Seamless Steel Tube

针对无缝钢管张减轧制过程中出现的壁厚横向分布不均现象,提出采用粘弹塑性有限元法建立轧制结果的高精度预测模型。通过高温压缩试验测定了材料的真应力-真应变曲线,根据粘弹塑性本构方程对材料力学性能测试曲线进行拟合,采用热力耦合显式算法对模型进行求解,以Ф114×20.0 mm规格小口径厚壁管的张减工艺进行工业试验对仿真模型的精度进行验证,结果表明仿真所得壁厚尺寸与试验结果沿周向变化规律一致,内壁形状均为六边形,6个壁厚最大值平均值误差为0.35%,6个壁厚最小值的平均值误差为1.2%,说明建立的有限元模型具有很高的精度,可用于轧制结果的精准预测。

Focus on the phenomenon of transverse wall thickness variation of seamless steel tube in stretch-reducing,the visco-elastic plastic finite element method is proposed to set up the high precision prediction model of the rolling result.The material true stress vices true strain curve is measured by high temperature compression tests,and the visco-elastic plastic constitutive equation is obtained by fitting the test curves,then the model is solved by thermal-mechanical coupling method.The accuracy of the simulation model is verified by the industrial test for the stretch-reducing technique of steel tube of Ф114×20.0mm.Results show that the thickness distribution of simulation results along circumference is very similar to the test results,and both inner wall shapes are hexagon.The relative error of the average of the six thickness peaks is 0.35%,and the relative error of the average of the six thickness valleys is 1.2%.This proves that the finite element model is of high precision and can be used for accurate prediction of the rolling results.