Microstructure and grain boundary engineering of a novel Fe-Cr-Ni alloy weldment made with self-developed composition-matched weld filler metal  

自主研发焊材制备的新型Fe-Cr-Ni合金焊接接头的显微组织与晶界工程

作　　者：Yu ZHANG Hong-yang JING Lian-yong XU Yong-dian HAN Lei ZHAO Hai-zhou LI Zheng-xin TANG Tian-wang TONG 张宇;荆洪阳;徐连勇;韩永典;赵雷;李海舟;唐正焮;童天旺(天津大学材料科学与工程学院,天津300350;天津市现代连接技术重点实验室,天津300350;哈尔滨工业大学先进焊接与连接国家重点实验室,哈尔滨150001;昆山京群焊材科技有限公司,苏州215312)

机构地区：[1]School of Materials Science and Engineering,Tianjin University,Tianjin 300350,China [2]Tianjin Key Laboratory of Advanced Joining Technology,Tianjin 300350,China [3]State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology,Harbin 150001,China [4]Kunshan Gintune Welding Co.,Ltd.,Jiangsu 215312,China

出　　处：《Transactions of Nonferrous Metals Society of China》2020年第4期992-1004,共13页中国有色金属学报（英文版）

基　　金：Project(51475326)supported by the National Natural Science Foundation of China;Project(BHSF2017-22)supported by the Demonstration Program of National Marine Economic Innovation of Tianjin City,China。

摘　　要：The microstructure,texture,and yield strength of an advanced heat-resistant alloy weldment made with composition-matched weld filler were investigated.Scanning electron microscopy,energy dispersive spectroscopy,and electron backscatter diffraction were used to characterize the microstructural and textural changes.Various grain boundary engineering(GBE)processes were performed on the weldment.The yield strengths of the weldment at 973 K were obtained before and after GBE processing,and were mostly consistent with the theoretically predicted values.The coincident-site lattices,misorientation,and recrystallization of the weld metal after GBE were analyzed,and the results indicate that the increase in dislocation density and the improvement in special grain boundaries in the weld metal are the main reasons for the yield strength elevation of the weldment after GBE.The variation in elongation after high-temperature tests has the same tendency as that in the impact toughness with different GBE parameters,which is related to the coarsening behavior of carbides.研究由自主开发的成分匹配焊材制备的先进耐热合金焊接接头的显微组织、织构与屈服强度。采用扫描电镜、能谱仪和电子背散射技术进行表征。针对焊件开展不同参数的晶界工程,测试经历晶界工程前后焊件在973 K下的屈服强度,其实验结果与预测值相近。通过观察晶界工程处理后试样的重合位置点阵、晶粒取向差和再结晶现象,发现试样中位错密度和“特殊晶界”比例的增大是晶界工程处理后焊件屈服强度上升的主要原因。高温拉伸断后伸长率和冲击韧性随着不同晶界工程处理参数的变化趋势相近,这与碳化物的粗化行为有关。

关 键 词：grain boundary engineering advanced Fe-Cr-Ni alloy weld metal yield strength 

分 类 号：TG407[金属学及工艺—焊接]