大型锻件内部孔隙性缺陷修复效果对疲劳性能的影响  

Influence of repair effect for internal porosity defects on fatigue performance of heavy forgings

作　　者：刘前军 邱垚 信瑞山 骆建彬[1] 马庆贤[1] Liu Qianjun;Qiu Yao;Xin Ruishan;Luo Jianbin;Ma Qingxian(Key Laboratory for Advanced Materials Processing Technology of Ministry of Education,Department of Mechanical Engineering,Tsinghua University,Beijing 100084,China;Ansteel Beijing Research Institute Co.,Ltd.,Beijing 102211,China)

机构地区：[1]清华大学机械工程系先进成形制造教育部重点实验室,北京100084 [2]鞍钢集团北京研究院有限公司,北京102211

出　　处：《锻压技术》2022年第11期16-21,共6页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51775298)。

摘　　要：大型锻件在内部孔隙性缺陷锻合后,其疲劳强度等动态载荷力学性能恢复效果是决定锻件质量水平的重要因素之一。采用圆柱试件高温锻合模拟实验,研究了不同的塑性变形工艺下锻件内部孔隙性缺陷修复结合面的组织变化效果,以及对疲劳强度修复的影响。结果表明:仅通过一次镦粗,虽然锻件的内部孔隙性缺陷基本消失,但是由于结合面上组织不均匀、存在细小析出物等,其疲劳性能仅能部分恢复。通过高温条件下两次镦粗加两次拔长工艺,其结合面的疲劳强度基本恢复至初始组织状态对应的性能指标。研究结果为制定合理的锻造工艺、保证锻后疲劳等力学性能恢复至初始状态提供了理论依据。After the internal porosity defects of heavy forgings are forged, the recovery effect of dynamic load mechanical properties such as fatigue strength is one of the important factors determining the quality level of heavy forgings. Therefore, using the simulation experiment of high temperature forging for cylindrical specimen, the effect of microstructure change on the joint surface for internal porosity defects in forgings under different plastic deformation processes and the repair effect of fatigue strength were studied. The results show that although the internal porosity defects basically disappear through only one upsetting, the fatigue properties can only be partially repaired due to the uneven microstructure and small precipitates on the joint surface. By two upsetting and two drawing processes at high temperature, the fatigue strength of joint surface is basically restored to the performance index corresponding to the initial microstructure state. Thus, the research results provide a theoretical basis for formulating a reasonable forging process and ensuring that the mechanical properties such as fatigue after forging are restored to the initial state.

关 键 词：大型锻件 锻造工艺 孔隙性缺陷修复 显微组织 疲劳强度 

分 类 号：TG306[金属学及工艺—金属压力加工]