Pre-deformation induced precipitation of alloy carbides and its effect on residual stress

The plasticity generated by carbide precipitation during tempering can relax the residual stress. For low-carbon micro alloyed steel 700L. The plastic behavior resulting from carbide precipitation leads to low stress relaxation. And it is prone to plate shape problems such as warping and edge waves. How to enhance carbide precipitation to relax stress has always been the goal pursued by researchers. In this paper, I discussed the effect of carbide precipitation on stress relaxation by applying pre-deformation to intervene the precipitation law of carbides. It is found that pre-deformation can interfere with the precipitation behavior of carbides during tempering, which in turn affects the relaxation degree of residual stress. Applying pre-deformation can inhibit the precipitation of cementite, improve the dispersion degree and precipitation size of alloy carbides, and improve the relaxation degree of residual stress in the tempering process. With the increase of deformation, the precipitation of cementite during tempering is inhibited, the precipitation of cementite decreases, the precipitation of alloy carbides increases and distributes more dispersed, and the size of alloy carbides decreases from 11.4 nm to 8.6 nm. After pre-deformation tempering, the residual stress is greatly relaxed, up to 85.09%.