淬火高强板矫直过程的残余应力计算模型

Calculation Model of Residual Stress During Quenching and Straightening of High-strength Plate

高强板材在生产淬火过程中产生的较大残余应力,会造成板型缺陷和产品性能的下降。为此,对Q960E高强钢的矫直过程,采用残余应力数值计算、实验和热力耦合仿真的方法,研究板材在矫直全过程中残余应力的变化。通过淬火热处理,高强板表面形成276.3 MPa左右的压应力,内部形成与之反向的拉应力,在矫直过程中,表面塑性变形最大,最终板材表面应力减少到100 MPa以下,与实验误差在15%以内;随着表面层到中心层塑性变形的递减,心部残余应力一直保持为200 MPa左右。结果表明:辊式矫直工艺能够有效降低板材残余应力,对表面残余应力影响较大,对心部残余应力影响较小;同时,也验证了该计算模型计算残余应力方法的正确性,为降低板材残余应力的矫直工艺提供了有效的计算方法。

In order to reduce the large residual stresses,which is generated in the production of high-strength plates during the quenching process and results in plate defects and product quality degradation.Numerical calculations of residual stresses,experiments and thermodynamic coupling simulations were carried out to study the changes of residual stresses during the whole process of straightening of Q960 E high-strength steel.After quenching and heat treatment,a compressive stress of about 276.3 MPa was formed on the surface of the high-strength plate,and a tensile stress was formed in the opposite direction.The results showed that the roll straightening process could effectively reduce the residual stress of the sheet,and had a greater effect on the surface residual stress and a smaller effect on the core residual stress.This result also verifies the correctness of the calculation model for calculating the residual stress,which provides an effective calculation method for the straightening process to reduce the residual stress of the sheet.