摘要
采用TIG焊对K4169高温合金薄片中铸造组织缺陷进行修复,并对修复前后的合金薄片进行疲劳性能测试和显微组织分析。结果表明:铸造缺陷对合金薄片疲劳性能的影响很大,含铸造缺陷的合金薄片疲劳寿命不到3万周次,而不含铸造缺陷的合金薄片疲劳寿命达7.1万周次。含铸造缺陷的样品经过TIG焊接修复后,疲劳寿命仍达6~9万周次,接近甚至超过了不含缺陷的试样疲劳寿命,这表明合适的焊接修复方法不会降低高温合金薄片的疲劳性能。铸件焊接修复后疲劳寿命高的原因是,焊缝中析出的较粗大相数量多、分布均匀,且疲劳裂纹扩展过程中产生较多的二次裂纹引发了裂纹偏移和扩展路径增长。
TIG welding method was used to repair the defects of the cast structure in the K4169 superalloy plates,and the fatigue performance test and microstructure analysis of the alloy plates before and after repair were performed.The results show that casting defects have a great in-fluence on the fatigue performance of alloy plates.The fatigue life of alloy plate with casting defects is less than 30000 cycles,while the fatigue life of alloy plate without free casting defects reaches 71000 cycles.After TIG welding repair of the defective specimens,the fatigue life of the specimen reaches 60000 to 90000 cycles,which is close to or even exceeding the fatigue life of the samples without defects.This shows that suitable welding repair method will not reduce the fatigue performance of K4169 superalloy.The reason for the high fatigue life of castings after welding repair is that the number of coarser phases precipitated in the weld is large and evenly distributed,and more secondary cracks are gene-rated during the fatigue crack propagation process,which leads to crack offset and growth path growth.
作者
许章华
谢志雄
康茂东
王俊
董仕节
彭志贤
刘静
XU Zhanghua;XIE Zhixiong;KANG Maodong;WANG Jun;DONG Shijie;PENG Zhixian;LIU Jing(Hubei Provincial Key Laboratory of Green Light Industrial Materials,Hubei University of Technology,Wuhan 430070,China;Shanghai Key Laboratory of Advances High-temperature Materials and Precision Forming,Shanghai Jiao Tong University,Shanghai 200240,China;Wuhan Polytechnic University,Wuhan 430023,China;The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第22期22115-22120,共6页
Materials Reports
基金
国家自然科学基金项目(51971142)
航空科学基金项目(2018ZE57012)。
