不锈钢复合板轧制成形过程特性研究

Study on characteristics of rolling process for stainless steel composite plate

利用Gleeble-3800热模拟实验机研究了304不锈钢和Q235低碳钢复合板在变形温度950～1150℃、应变速率0. 01～0. 1 s^(-1)条件下的热变形行为。为了描述高温流动特征,建立了不锈钢复合板的高温流变应力方程。由实验数据可知,流变应力随变形温度和应变速率变化明显,应变速率越大,变形温度越低,流变应力越大。应用Deform-3D有限元软件模拟了热轧不锈钢复合板在轧制过程中的变形特性,并对不同压下率下复合板厚度方向上的应力场、温度场和轧制力的分布规律进行了分析。结果表明:不锈钢复合板的表面应力最大,并由表层向内部逐渐减少;结合界面附近由于塑性功、热传导、热对流等综合因素,使得温度高于表面;通过实验测出的轧制力值与模拟值的变化趋势一致,且误差在15%左右,该模拟结果可为实际的生产提供参考。

The thermal deformation behaviors of composite plate for 304 stainless steel and Q235 low carbon steel at deformation temperature of 950-1150 ℃ and strain rate of 0. 01-0. 1 s^-1were studied by thermal simulation test machine Gleeble-3800,and the flow stress equation at high temperature of stainless steel composite plate was established to describe the high temperature flow characteristics. The experimental data show that the flow stress changes significantly with the change of temperature and strain rate,and the greater the strain rate and the lower the deformation temperature are,the greater the flow stress is. Then,the deformation characteristics of hot rolled stainless steel composite plate during the rolling process were simulated by finite element software Deform-3D,and the distribution of stress field,temperature field and rolling force in the thickness direction of the composite plate under different reduction rates were analyzed.The results show that the surface stress of the stainless steel composite plate is the largest and gradually decreases from the surface to the interior,and the temperature near the bonding interface is higher than that in the surface due to the plastic work,heat conduction,heat convection,and so on. Furthermore,the variation trend of the rolling force values measured by the test is consistent with the simulated values,and the error is about 15%. Thus,the simulation results can provide reference for the actual production.