Taking the sample of 120 mm×80 mm×15 mm discarding concave of steel CrWMn,by measuring hardness,detecting burn,observing microstructure and testing process,the causes of the crack on the concave of steel CrWMn were analyzed,which included excessively high quenching temperature,severely insufficient tempering and improper grinding process etc..On this basis,the corresponding preventive measures are put forward,such as choosing proper quenching temperature and cooling speed,uniformly heating,sufficiently temp...