电焊机2025，Vol.55Issue(8)：68-73,99,7.DOI:10.7512/j.issn.1001-2303.2025.08.07
EQ NiCrFe-7A带极堆焊熔敷金属DDC裂纹敏感性研究
Study on the DDC Sensitivity of the Deposited Metal of Nuclear Grade EQ NiCrFe-7A Solder Strip
摘要
Abstract
Based on the key core technology of Hualong-1 and in-service nuclear power units,the EQ NiCrFe-7A weld metal was taken as the research object to understand the change of the microstructure and crack sensitivity of Ni-based 690 alloy in high temperature service.The crack sensitivity and microstructure evolution of the material at different temperatures were characterized by strain-to-fracture test and scanning electron microscopy.The results show that the high temperature ductility-dip crack sensitivity of EQ NiCrFe-7A weld metal decreases with the increase of temperature,and the crack sensi-tivity temperature range is 950℃-1050℃,with the minimum critical strain of 4.21%.The high temperature ductility-dip crack is affected by the grain boundary morphology and the distribution of precipitated phases.With the increase of tempera-ture,the proportion of large-angle grain boundaries increases,the residual stress increases,the pinning effect of precipitated phases weakens,and the high temperature ductility-dip crack tendency increases.The residual stress enriched near the crack can promote the recrystallization grain and twin,and fasten the crack propagation to some extent.关键词
EQ NiCrFe-7A焊缝金属/应变-裂纹试验/晶界特征/高温失塑裂纹Key words
EQ NiCrFe-7A weld metal/strain-to-fracture test/grain boundary characteristics/high temperature plastic defor-mation crack分类
矿业与冶金引用本文复制引用
孟长鑫,曹睿,杨飞,徐晓龙,王若蒙,蒋勇..EQ NiCrFe-7A带极堆焊熔敷金属DDC裂纹敏感性研究[J].电焊机,2025,55(8):68-73,99,7.基金项目
甘肃省科技重大专项(22ZD6GA008) （22ZD6GA008）
国家自然科学基金(52175325) （52175325）
国家自然科学基金(51961024) （51961024）
国家自然科学基金(52071170) （52071170）
