Experimental research on the effect of induction reheating on the microstructure and mechanical properties of hot-rolled low-alloy steel plate

Abstract

Electric induction reheating is used to control the temperature of hot-rolled steel products. To investigate the effect of this on microstructure and mechanical properties, hot-rolled low-alloy steel plate was cooled, reheated, and then either quenched or normalized. Analysis of the microstructure and mechanical properties showed that this process had a greater effect on quenched steel plate than on normalized steel plate. Reheating was found to affect the precipitation of alloy carbonitrides, and the recovery and recrystallization of deformed austenite. In the single-phase region, the lower cooling temperature resulted in better mechanical properties. In normalized steel plate, the interlamellar spacing of pearlite (ISP) increased from 118nm to 165nm after induction reheating. In steel plate quenched with a 70oC temperature difference, induction reheating reduced the strength difference from 80MPa to 23MPa. Our results provide useful references for optimizing electric induction and improving the uniformity of the mechanical properties of low-alloy steel.