内裂纹热塑变形修复组织演变及冲击性能恢复效果  

Evolution on thermal plastic deformation repair microstructure and impact performance recovery effect of internal cracks

作　　者：邱垚 信瑞山 骆建彬[1] 马庆贤[1] Qiu Yao;Xin Ruishan;Luo Jianbin;Ma Qingxian(Key Laboratory for Advanced Materials Proces sing 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》2020年第10期1-6,共6页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51775298);河北省自然科学基金资助项目(E2019318022)。

摘　　要：大型锻件生产过程中会产生内裂纹等孔隙性缺陷,这类缺陷的存在具有重大安全隐患。采用高温热塑变形的方式修复低碳钢内裂纹,采用扫描电镜、金相分析等方法分析内裂纹修复区组织的演变情况,并通过标准夏比实验研究了冲击性能恢复情况。结果表明:修复过程中,仅通过一次镦粗,可以使得内裂纹完全消失,但是冲击性能只能部分恢复;通过在较高温度下的两镦一拔工艺,内裂纹完全消失的同时,冲击性能也可以完全恢复,这与内裂纹修复区晶粒分布有关。此外,经过不同的热塑变形工艺均可以在内裂纹修复区观察到Al元素和Si元素聚集。该研究结果为大型锻件内裂纹修复工艺标准的制定提供了参考依据。Porosity defects such as internal cracks occur during the production process of heavy forgings,and the existence of such defects has major safety hazards.Therefore,the internal cracks of low-carbon steel were repaired by high temperature thermal plastic deformation,the evolution condition of microstructure in the internal crack repair area was analyzed by SEM,metallographic analysis and other methods,and the impact performance recovery condition was studied by standard Charpy experiments.The results show that in the repair process,the internal cracks disappear completely by only one upsetting,but the impact performance is only partially recavered.However,through the two upsetting and one drawing process at a higher temperature,while the internal cracks disappear completely,the impact performance is also fully recovered,which is related to the grain distribution in the internal crack repair area.In addition,after different thermal plastic deformation processes,the segregation of Al and Si elements is observed in the internal cracks repair area,and the results lay the foundation for the establishment of internal cracks repair process standard for heavy forgings.

关 键 词：大型锻件 热塑变形 内裂纹修复 显微组织 冲击性能 

分 类 号：TG306[金属学及工艺—金属压力加工]