摘要
研究了采用钨极氩弧焊(TIG)焊接的Zr702合金焊接接头在8 mol/L沸腾硝酸中的应力腐蚀、电化学腐蚀、均匀腐蚀行为及其失效机理。结果表明:TIG焊接后,Zr702合金焊接接头熔合区和热影响区晶粒发生粗化;热影响区产生残余拉应力,平行于焊缝的残余应力达到179.68 MPa,垂直于焊缝的残余应力达到134.94 MPa。Zr702合金焊接接头的均匀腐蚀速率比母材高50%,这是由于组织内存在的残余应力会诱导合金溶解腐蚀。在拉应力的作用下,Zr702合金焊接接头表面的钝化膜沿着垂直于拉应力方向开裂,表现为明显的解理断裂特征,导致接头的应力腐蚀敏感性升高,存在应力腐蚀开裂的风险。
The stress corrosion,electrochemical corrosion,uniform corrosion behaviors and failure mechanism of Zr702 alloy joints welded using tungsten inert gas(TIG)were investigated in 8 mol/L boiling nitric acid.The results show that the grains in the fusion zone and heat affected zone(HAZ)of Zr702 alloy welded joints undergo coarsening after welding.The residual tensile stress generates in HAZ,which is reaching 179.68 MPa and 134.94 MPa in parallel and perpendicular to the weld seam,correspondingly.The uniform corrosion rate of Zr702 alloy welded joint is 50%higher than the base material,because that the residual stress in HAZ can induce alloy dissolution corrosion.Under the action of tensile stress,the passive film on the surface of Zr702 alloy welded joint cracks along the direction perpendicular to tensile stress,exhibiting obvious cleavage fracture characteristics,resulting in increasing stress corrosion sensitivity of the joints and a risk of stress corrosion cracking.
作者
郭计增
徐建平
房菲
刘承泽
易全伟
吴金平
王丹丹
张于胜
Guo Jizeng;Xu Jianping;Fang Fei;Liu Chengze;Yi Quanwei;Wu Jinping;Wang Dandan;Zhang Yusheng(China Nuclear Power Engineering Co.,Ltd.,Beijing 100840,China;Xi’an Rare Metal Materials Institute Co.,Ltd.,Xi’an 710016,China)
出处
《钛工业进展》
CAS
2024年第3期29-34,共6页
Titanium Industry Progress
基金
国家自然科学基金资助项目(52203383,12205242)
中国博士后科学基金面上资助项目(2023M742821)
陕西省创新能力支撑计划项目(2023KJXX-095)
陕西省博士后科研项目(2023BSHGZZHQYXMZZ24)。
