超高强马氏体钢开裂失效分析  

Cracking failure analysis of ultra-high strength martensite steel

作　　者：孙璐[1] 李建英[1] 魏焕君[1] 李征 李涛 程晓英[3] Sun Lu;Li Jianying;Wei Huanjun;Li Zheng;Li Tao;Cheng Xiaoying(Tangshan Iron and Steel Group Co.,Ltd.,Tangshan Hebei 063000,China;College of Metallurgy and Energy,North China University of Science and Technology,Tangshan Hebei 063000,China;School of Material Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]唐山钢铁集团有限责任公司,河北唐山063000 [2]华北理工大学冶金与能源学院,河北唐山063000 [3]上海大学材料科学与工程学院,上海200444

出　　处：《金属热处理》2023年第1期261-266,共6页Heat Treatment of Metals

基　　金：河北省自然科学基金(E2020318006)。

摘　　要：由于超高强马氏体钢零件安全服役期发生开裂,因而对失效及非失效的零件、基材进行分析。结果表明,通过恒应变试验中的U型弯梁试验得知失效及非失效的零件的基材都具有良好的抗氢致延迟开裂能力。基材由于生产工艺的差异造成组织结构不同,开裂基材组织为片状马氏体,未开裂基材组织为板条状马氏体。在加工成相同零件时,由于马氏体的组织结构差异,造成加工成形过程中内部协同变形均匀程度不同,开裂件内残留较大应力,且开裂件组织内部形成大量位错塞积后造成应力集中,局部应力率先达到极限,最终引发开裂。Cracked and uncracked ultra-high strength martensitic steel parts and the corresponding raw materials steels were analyzed due to phenomenon of cracking of the parts in their safe service period. The U-shaped bending beam experiment results in constant strain test show that both the raw materials of cracked and uncracked parts have good resistance to delayed cracking caused by hydrogen. Due to the difference of the production processes, the microstructure of the raw materials is plate martensite for the cracked part and lath martensite for the uncracked part, respectively. When machining into the same kind of parts, due to the structural difference of the martensite, the internal collaborative deformation uniformity is different in machining and forming processes, thus the residual stress in the cracked parts is larger. In addition, the stress concentration is caused by the formation of a large number of dislocation pile-ups in the structure of cracked parts, the local stress reaches the limit first, resulting in cracking.

关 键 词：超高强马氏体钢 组织结构 内应力 位错 开裂失效 

分 类 号：TG142.24[一般工业技术—材料科学与工程]