Quenching Cracking Analysis of 40Mn2 Steel Back-up Roll

By means of macroscopic examination, chemical composition analysis, metallographic examination and so on, the quenching cracking reason of back-up roll made with 40Mn2 steel was analyzed. The results showed that the unreasonable quenching process was main reason, and the coarse original microstructure accelerated quenching cracking. Finally, the improvement measures were put forward.