Ti-811合金棒材热连轧过程有限元数值模拟及验证

Finite Element Numerical Simulation and Verification of Hot Continuous Rolling Process of Ti-811 Alloy Bar

采用有限元法对Ti-811合金棒材热连轧过程进行数值模拟,分析变形过程中轧件应力场、应变场和温度场的数值以及分布规律,并基于数值模拟结果进行轧制验证,为制定Ti-811合金棒材轧制工艺提供指导。结果表明:模拟连续轧制过程中轧件的最大应力位于与轧辊接触的表面,且由边部到心部逐渐降低;随着轧制道次的增加,应力值逐渐下降、应变量逐渐增大;轧件在各道次的变形过程中表层和心部存在差异,心部变形量大于边部变形量;轧件与轧辊接触的表面层有明显温降,当轧件脱离轧辊后表面层温度逐渐回升,轧制结束后表面层温度回升至初始温度,但心部因变形热积聚温度略有升高,最大温升值达到14℃。基于数值模拟结果在热连轧机组上进行轧制验证,所轧制的Ti-811合金棒材外形尺寸良好,且组织与力学性能满足GJB 9567—2018《叶片用TA11和TC6钛合金棒材规范》要求。

The finite element method was used to analysis the numerical value and distribution rules of hot continuous rolling process of Ti-811 alloy bar,which include stress field,strain field and temperature field.The results show that the maximum stress of rolling bar during rolling process is located at the surface which contact with the rolls,the stress distribution gradually decreases from the edge to the center;with the increase of rolling,the stress value gradually decreases,and the strain variable increases;there is difference between the surface and heart of the rolling bar in the deformation process of each pass,and the deformation amount at the center is greater than the edge;the temperature of the surface layer which contact with rolls has obvious cooling,when the rolling bar removed from the roll,the surface layer temperature rises gradually,and when the rolling is over,the surface layer temperature rises to the initial temperature,but the center temperature of rolling bar rises slightly duo to the accumulation deformation heat,the maximum temperature appreciation reaches 14℃.Based on the numerical simulation results,rolling test was conducted on the hot continuous rolling mill.The rolled bars have good overall dimension,the microstructure and mechanical properties meet the requirements of GJB 9567—2018“Specification for TA11 and TC6 titanium alloy bars for blade and vane”.