摘要
引入IN718合金作为中间层可以改善IN690镍基合金超声激励TIG接头高温失塑裂纹敏感性,接头需要经热处理调控组织成分.通过不同的焊后热处理工艺流程,探究固溶温度对接头显微组织、析出相分布和力学性能的影响规律.结果表明,固溶热处理促使焊缝与母材晶粒尺寸增大,碳化物沿晶界偏聚.随着固溶+双时效热处理工艺中固溶温度的提高,试样晶界碳化物均发生明显粗化.固溶温度为1150℃的固溶+双时效处理后试样接头显微硬度与焊态试样接近,固溶温度为980℃与固溶温度为1050℃的固溶+双时效处理的试样硬度相比焊态提升10~20 HV.固溶温度为1050℃的固溶+双时效处理后的试样断后伸长率与抗拉强度最高,达到38.4%与630 MPa,断口中韧窝形态呈等轴化且分布更加均匀,表现为韧性断裂与穿晶断裂模式.综合显微组织与力学试验结果分析,固溶温度为1050℃的固溶+双时效的焊后热处理工艺可以使加入IN718中间层的IN690接头得到良好的性能.
The addition of IN718 alloy as an interlayer effectively reduces the high-temperature ductility-dip cracking susceptibility in ultrasonically excited TIG joints of IN690 nickel-based alloy,and the joint needs to undergo heat treatment to regulate its microstructure composition.By implementing different post-weld heat treatment processes,this study investigated the influence of solution temperature on the joint’s microstructure,precipitate distribution,and mechanical properties.Results show that solution heat treatment promotes grain coarsening in both the weld and base material while inducing carbide segregation along grain boundaries.Results show that solution heat treatment promotes grain coarsening in both the weld and base metal while inducing carbide segregation along grain boundaries.With increasing solution temperatures during the solution+double-aging heat treatment,significant carbide coarsening at grain boundaries is observed across all specimens.The microhardness of joints subjected to 1150℃solution+double-aging heat treatment approximates that of as-welded specimens,while specimens treated at 980℃and 1050℃solution+double-aging exhibit 10~20 HV hardness increments compared to the as-welded condition.Specimens processed with 1050℃solution+double-aging demonstrate optimal mechanical performance,post-fracture elongation of 38.4%and tensile strength of 630 MPa.Their fracture surfaces exhibit uniformly distributed equiaxed dimples,indicative of ductile fracture and transgranular failure modes.Comprehensive analysis of microstructural evolution and mechanical test results confirms that the 1050℃solution+double-aging post-weld heat treatment process enables IN690 joints incorporating IN718 interlayers to achieve optimal comprehensive properties.
作者
张星越
韩柯
雷玉成
陈浩
王丹
马建国
ZHANG Xingyue;HAN Ke;LEI Yucheng;CHEN Hao;WANG Dan;MA Jianguo(School of Materials Science&Engineering,Jiangsu University,Zhenjiang,212013,China;Institute of Plasma Physics,Chinese Academy of Sciences Hefei Institutes of Physical Science,Heifei,230031,China;Institute of Energy,Hefei Comprehensive National Science Center,Hefei,230001,China;Huainan New Energy Research Center,Anhui Province Key Laboratory of Special Welding Technology,Huainan,232063,China)
出处
《焊接学报》
北大核心
2025年第7期73-80,共8页
Transactions of The China Welding Institution
基金
国家自然科学基金资助项目(52205368)
特种焊接技术安徽省重点实验室资助项目(2023SW1003)。
关键词
超声激励
热处理
IN690镍基合金
显微组织
力学性能
ultrasonically excited
heat treatment
IN690 nickel-based alloy
microstructure
mechanical property
