TC4钛合金热丝钨极氩弧焊接头组织性能研究
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摘要
对TC4钛合金热丝钨极氩弧焊(hot-wire-TIG)焊接接头组织与性能进行研究,采用金相显微镜观察焊接接头各区域的微观组织特点,并对接头显微硬度和力学性能进行了测定。结果表明,钛合金热丝TIG焊接接头内部无焊接缺陷,焊缝性能优良;焊缝为典型的铸造组织,由粗大的柱状晶和少量等轴晶组成,晶粒内部可以看到细长的针状α′相;热影响区形成粗大的等轴晶粒,其组织主要有细针状α相和残余β相构成;焊接接头的抗拉强度均值为924 MPa,与母材相当;热丝TIG焊缝冲击功较母材提升明显,基本达到母材的1.5倍以上,最大达到66 J;焊缝冷弯角度达到指标要求。
The microstructure and properties of TC4 titanium alloy welded joint by hot-wire tungsten inert gas arc welding(TIG) were studied. Metallographic microscope was used to observe the microstructure characteristics of the welded joints, and the microhardness and mechanical properties of the joints were also measured. The results show that there is no welding defect inside the hot-wire TIG welded joint of titanium alloy, and the weld performance is excellent; The weld is of a typical casting structure consisting of thick columnar grains and a small number of equiaxed grains, and elongated needle like α′ phase can be seen inside the grains; Coarse equiaxed grains are formed in the heat affected zone, which mainly consist of fine needle like α phase and residual β phase; The average tensile strength of the welded joints is 924 MPa, equivalent to that of the base metal; The impact energy of welding line by hot-wire TIG is obviously higher than that of the base metal, and the maximum reaches 66 J, more than 1.5 times higher than that of base metal; The cold bending angle of the welding line meets the requirement of the index.
The microstructure and properties of TC4 titanium alloy welded joint by hot-wire tungsten inert gas arc welding(TIG) were studied. Metallographic microscope was used to observe the microstructure characteristics of the welded joints, and the microhardness and mechanical properties of the joints were also measured. The results show that there is no welding defect inside the hot-wire TIG welded joint of titanium alloy, and the weld performance is excellent; The weld is of a typical casting structure consisting of thick columnar grains and a small number of equiaxed grains, and elongated needle like α′ phase can be seen inside the grains; Coarse equiaxed grains are formed in the heat affected zone, which mainly consist of fine needle like α phase and residual β phase; The average tensile strength of the welded joints is 924 MPa, equivalent to that of the base metal; The impact energy of welding line by hot-wire TIG is obviously higher than that of the base metal, and the maximum reaches 66 J, more than 1.5 times higher than that of base metal; The cold bending angle of the welding line meets the requirement of the index.
引文
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[3] XIONG J,LI S,GAO F,et al.Microstructure and mechanical properties of Ti6321 alloy welded joint by GTAW [J].Materials Science & Engineering A,2015,640:419—423.
[4] 高福洋,廖志谦,熊进辉.船用钛合金焊接接头精细组织表征[J].焊接学报,2016,37 (4):124—128.
[5] 王陆钊.热丝TIG焊的工艺及性能研究[D].镇江:江苏科技大学,2010.
[6] 赵福海,华学明,叶欣,等.热丝TIG焊方法最新研究进展[J].热加工工艺,2011,40(3):151—155.
[7] SHINOZAKI K,YAMAMATO M,MITSUHATA K,et al.Study on high-speed-welding with hot-wire TIG welding methods using pulsed current to heat filler wire[J].Prep.Nat.Meet.Jws,2006:64.
[8] 穆春艳.不同焊接工艺下TC4钛合金焊接接头的晶粒尺寸和微观组织变化[J].铸造技术,2015,36(5):1267—1269.
[9] HORI K,WATANABE H,MYOGA T,et al.Development of hot wire TIG welding methods using pulsed current to heat filler wire-research on pulse heated hot wire TIG welding processes[J].Welding International,2004,18(6):456—468.