1. Institute of Special Steel， Central Iron and Steel Research Institute, Beijing 100081, China 2. Technology Center, Dongbei Special Steel Group Co., Ltd., Fushun 113001, Liaoning, China 3. Wuxi Yousiweike Petroleum Drilling Tools Co., Ltd., Wuxi 214154, Jiangsu, China
Abstract：Analysis of SEM, metallography and mechanical property was established based on the failed and unused H13 mandrels with the same heat treatment process. The results show that the failure of mandrel is mainly caused by two kinds of cracks (heat checking and mechanical wear crack), and matrix oxidation can be seen with the development of cracks. The carbides coarsening, recovery of martensite and reduction of hardness can be found on the edge of failed mandrel, and the more close to the surface, hardness decreases more obviously.The reduction of hardness and strength is the main reason of the early appearance of heat checking on the surface of No.1 mandrel, while toughness shortage seriously cause deep mechanical wear crack.
周健，马党参，康爱军 肖瑞勇 刘振天 陈再枝. H13芯棒失效过程中的组织及力学性能变化[J]. 钢铁, 2013, 48(2): 69-74.
ZHOU Jian,MA Dang-shen,KANG Ai-jun,XIAO Rui-yong,LIU Zhen-tian,CHEN Zai-zhi. Change of Microstructure and Mechanical Property in the Failure Process of H13 Mandrel. Iron and Steel, 2013, 48(2): 69-74.
M Akiyama,K Tsubouchi, M Tsumure. .A study of the mechanism of crack initiation on a mandrel bar for mandrel mill rolling in a seamless tube[J].,Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications,2000,214(2):61-70
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M Akiyama,K Tsubouchi, M Tsumure. .A study of the mechanism of crack initiation on a mandrel bar for mandrel mill rolling in a seamless tube[J].,Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications,2000,214(2):61-70
2013, Vol. 48 
