固溶时效对TC4ELI钛合金电子束焊接接头组织与力学性能的影响  

Effect of Solution Treatment and Aging on Microstructure and Mechanical Properties of Electron Beam Welded Joints of TC4ELI Titanium Alloy

作　　者：廖志谦[1] 高奇 晏阳阳[1] 雷小伟[1] 方乃文[2] 郝健 余巍[1] 刘希林[1] LIAO Zhiqian;GAO Qi;YAN Yangyang;LEI Xiaowei;FANG Naiwen;HAO Jian;YU Wei;LIU Xilin(Luoyang Ship Material Research Institute,Luoyang 471023,Henan,China;Harbin Welding Institute Limited Company,China Academy of Machinery Science and Technology Group Co.,Ltd.,Harbin 150028,China;China Ship Development and Design Center,Shanghai 201108,China)

机构地区：[1]洛阳船舶材料研究所(中国船舶集团有限公司第七二五研究所),河南洛阳471023 [2]中国机械总院集团哈尔滨焊接研究所有限公司,哈尔滨150028 [3]中国舰船研究设计中心,上海201108

出　　处：《焊管》2025年第3期44-49,54,共7页Welded Pipe and Tube

基　　金：装备预研项目“易焊接抗蠕变结构钛合金技术研究”(项目编号50922010304)。

摘　　要：为了加强钛合金电子束焊接接头的强韧性调控,采用真空电子束焊接方法实现了25 mm厚度TC4ELI钛合金一次性焊接成形,对焊接接头的组织及力学性能进行分析,并研究了固溶+时效热处理对接头组织及力学性能的影响。结果表明:TC4ELI钛合金电子束焊接后,接头焊缝区的细针状α'马氏体板条宽度为360~766.9 nm,长宽比>10,对提升接头的硬度、强度和降低冲击韧性有重要作用。焊接态接头抗拉强度达到990 MPa,冲击韧性值16~20 J。经过高温920℃/2 h固溶处理后的接头焊缝区及热影响区组织发生明显转变,α'马氏体相转变为粗大的片层α相,强度降低,冲击韧性明显提升。固溶+时效(920℃/2 h+500℃/3 h)处理后,焊缝区的片层α相网篮组织交错分布增强,热影响区和母材的β相基体上时效析出细小片层次生α相,等轴α相更加清晰,接头的组织趋于稳定、力学性能趋于一致,接头强度达到954 MPa,冲击韧性约为30 J,接头强韧匹配性良好。To enhance the regulation of strength and toughness of titanium alloy electron beam welded joints,a vacuum electron beam welding approach was employed to realize the one-time welding and forming of 25 mm thick TC4ELI titanium alloy.The microstructure and mechanical properties of the welded joints were analyzed,and the impact of solid solution+aging heat treatment on the microstructure and mechanical properties of the joints was investigated.The results indicate that after electron beam welding of TC4ELI titanium alloy,the width of fine needle-shapedα'martensite laths in the weld zone of the joint is within the range of 360~766.9 nm,with a length-to-width ratio>10,which plays a crucial role in enhancing the hardness and strength of the joint and reducing the impact toughness.The tensile strength of the as-welded joint reaches 990 MPa,and the impact toughness value ranges from 16 to 20 J.After high-temperature solid solution treatment at 920℃for 2 h,obvious transformations occur in the microstructure of the weld zone and heat-affected zone of the joint,where theα'martensite transforms into coarse lamellarαphase,leading to a reduction in strength and a remarkable increase in impact toughness.After solid solution+aging(920℃/2 h+500℃/3 h)treatment,the interlaced distribution of the lamellarαphase basket structure in the weld zone is enhanced,and fine lamellar secondaryαphase precipitates on theβmatrix of the heat-affected zone and base metal,with the equiaxedαphase becoming more distinct.The microstructure of the joint tends to be stable,and the mechanical properties tend to be uniform.The joint strength reaches 954 MPa,and the impact toughness values are uniformly distributed at 30 J,demonstrating excellent strength-toughness matching of the joint.

关 键 词：钛合金 电子束焊 固溶时效处理 显微组织 接头性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]