Research on Banded Structure in 25CrMo Steel and Its Effect on Impact Toughness

The reasons for the formation of banded structure and the effects of banded structure on the transverse/ longitudinal impact toughness of 25CrMo steel were introduced.The results show that the composition segregation can cause the formation of banded structure.The segregation of elements C,Cr and Mn in the ingot was elongated along the rolling direction in rolling process.There is apparent microstructure difference between the segregation area and the matrix after heat treatment.The structure directionality can cause the mechanical property anisotropy of the steel.The process which can reduce the element segregation decreases the banded structure.