大规格调质材残余应力测试分析及稳定调质工艺

42CrMo系列≥Φ500mm大规格调质锻材回火后锯切时夹锯及锯切至心部产生炸裂，通过残余应力测试后，观察各向应力数值差值较大，且分布不均衡，经过系统分析明确锯切时开始夹锯、最后炸裂问题产生的根本原因、稳定调质工艺，包括水温、水冷时间、水冷后返热温度、回火冷却速度，回火快冷后补充回火。

Test analysis of residual stresses in large-scale quenched and tempered steel to stabilize quenc hing and tempering process

Clamping saw happened in cutting and burst accrued in cutting to the core in large size forg-ing and tempering steel of 42CrMo series with diameter more than 500mm after tempering.Through the residual stress testing, there was larger residual stresses difference, distribution of which was une-ven.By systematic analysis, the fundamental reasons that clamping saw happened in cutting and burst accrued in cutting to the core were found.Finally process measures had been adopted, such as, stabi-lizing quenching and tempering process, including water temperature, water cooling, heating tempera-ture after water cooling , tempering cooling speed, and supplementary tempering after fast cooling of supplementary tempering.