Analysis of Crack Susceptibility of Peritectic Steels Based on Surface Roughness

Abstract

Surface longitudinal cracking during solidification is a serious defect in the continuous casting of peritectic steels, which is dictated by the alloy composition and the cooling rate. Herein, to analyze the crack susceptibility of steels, surface roughness ( R a ), which is determined by the peritectic transformation contraction, is proposed to evaluate the cracking tendency of steels. First, the solidified surface roughness of some steels is obtained by a high‐temperature laser scanning confocal experiment under different cooling rates, and then the calculation formula and the criteria for surface roughness are obtained by data analysis. The results show that the peritectic transformation contraction and crack susceptibility reflected by surface roughness vary significantly with alloy compositions and cooling rates. In comparison with other methods, this method successfully contains the effect of alloy compositions and cooling rates on crack susceptibility. Good agreement between the predicted results and the experimental observations indicates that the crack susceptibility of steels can be evaluated reliably using their surface roughness.