Defect analysis of central cavity for A2 cold work die steel
LIU Zhen-tian1��ZHOU Jian2��MA Dang-shen2��QIU Li-peng1��LIU Bao-shi1
1. Dongbei Special Steel Group Co.�� Ltd.�� Fushun 113001�� China 2. Institute for Structural Materials��Central Iron and Steel Research Institute�� Beijing 100081�� China
Abstract��The cause of central cavity defect in cold work die steel A2 was discussed with OM�� SEM and EDS. The results showed that the test steel has serious segregation of primary carbides�� and the size and quantity of primary carbides in the center of the ingot are bigger than that on the edge. These carbides are in block aggregation. Cavity defects are mainly located in the heart of ingot�� while the inner surface of cavity defect is smooth. The formation of defects in A2 steel is pertaining to the remelting of Cr7C3 primary carbides. In addition�� the gap caused by the fractured large size primary carbides in the center of ingot�� small carbides segregated outside of the primary carbides�� nonmetallic inclusions and flake graphite could also induce the central cavity defects of A2 steel.
�����죬�� �������Σ�������������ʯ. A2����ģ�߸����Ŀ�ȱ�ݷ���[J]. �й������ڿ���, 2015, 33(3): 49-53.
LIU Zhen-tian��ZHOU Jian��MA Dang-shen��QIU Li-peng��LIU Bao-shi. Defect analysis of central cavity for A2 cold work die steel. Chinese Journal of Iron and Steel, 2015, 33(3): 49-53.
2015, Vol. 33 
