Effect of Residual Stress on the Continuous Cooling Transformation of High‐Strength Low‐Alloy Hot‐Rolled Strip

The external stress will change the transformation process and microstructure of the material, and the residual stress generated during the processing of the material will also affect the transformation. Herein, the effect of residual stress is simulated by applying uniaxial elastic loads during the continuous cooling of high‐strength low‐alloy hot‐rolled strip. The transformation process and microstructure of the samples under different stress conditions are investigated. The results show that residual stress can accelerate the transformation process, and the tensile stress is greater than the compressive stress. The degree of lattice mismatch in stressed samples is larger than that in unstressed samples, leading to dislocation proliferation. It is found that there is a phenomenon of residual stress‐induced grain growth according to the statistics of grain size of different samples. Due to the higher dislocation density and smaller curvature of the parent phase interface under compressive stress, the compressive stress samples have a higher nucleation rate, resulting in smaller grain size than the tensile stress samples. In addition, the transformation texture also changes under residual stress.