冷轧不锈钢管二辊模具优化模型的建立与验证

Establishment and validation of optimization model for two roller die of cold rolled stainless steel tubes

以皮尔格轧机冷轧304不锈钢管为例,建立二辊模具的关键参数优化模型.首先通过在不同应变速率下材料的拉伸试验获得真应力-应变曲线数据,通过对真应力-真应变曲线进行非线性拟合,获得304不锈钢的本构方程;然后根据皮尔格冷轧钢管的变形特点,结合增量理论得出钢管当量变形量的计算方法,融合孔型参数和各工艺参数之间的关系,推导出二辊模具孔型变形区压下段和精整段长度之比Q值与材料应变速率之间的优化方程;最后利用材料卸载定律解出冷轧304不锈钢管过程特定阶段时的应变速率值,解出不同尺寸精度无缝钢管的Q值.以计算出的Q值为二辊模具的设计参数,根据皮尔格轧机孔型设计优化程序设计出轧辊和芯棒,并利用有限元仿真软件和现场轧制试验验证了本优化模型的正确性,验证成品管能够达到预期的尺寸精度.

The cold rolling 304 stainless steel tubes by Pilger pipe mill was took as example to estab‐lish the key parameter optimization model of two roller die .At first ,by dealing the data got from the tensile test when the material was in different strain rate and after nonlinear fitting ,the constitutive equation of 304 stainless steel w as obtained .Besides , the optimization equation of the value of Q , which was the ratio of the length of the reduction and finishing zone during the rolling ,and the strain rate of the material was deduced on the basis of the relationship between the pass parameter and every technological parameter combined with the numerical method of the equivalent deformation according to the plastic deformation feature and the incremental theory .Finally ,the value of Q of different di‐mensional accuracy was solved according to the value of strain rate gained from the law of material′s unloading .By making the value of Q as the pass parameters ,combined with the roller and the man‐drel ,the simulation was conducted ,and through the actual rolling test ,the reliability and correctness of the optimization model w ere verified .