TC4钛合金与Nb—W—Mo—Zr铌合金的真空电子束焊接工艺研究

采用真空电子束焊对TC4钛合金和Nb—W—Mo—Zr铌合金进行了成功焊接，焊接的基本工艺参数为：炉室真空度≤3．0×10^-2 Pa，枪室真空度≤1．5×10^-3 Pa，焊接电压56-60kv，束流20～25mA，工件的移动速度为550～600mm／min。用扫描电镜对焊接组织进行了观测，并作了X射线无损探伤。结果表明，热影响区和熔合区组织致密，焊缝熔透性好，无气孔。熔合区主要为胞状束凝固结构，基本无枝晶出现。X射线探伤结果得出，焊缝质量满足国家一级标准。焊接组件在室温下的力学性能为：Rm=595MPa，Rp0.2=482MPa，A=20％，Z=63％。

The Study on EB Welding Technology of TC4 Titanium Alloy and Nb-W-Mo-Zr Alloy

The vacuum electron beam welding method was successfully used for TC4 and Nb alloy welding, during which the process parameters are as follow： vacuum in the furnace chamber is ≤3.0×10^-2 Pa, in the gun chamber ≤1.5×10^-3 Pa, welding voltage 56-60 kV, bind current 20-25 mA and the displacement velocity of workpiece 550-600 mm/min. The weld was observed by SEM and X-ray defect detection. It shows that the microstrncture of heat affected zone and fusion zone is cell structure which is dense without pore and almost no dentrite. The result of X-ray defect detection indicated that the quality of weld joint meet a national criterion in first grade, whose mechanical properties at room temperature are Rm=595 MPa, Rp0.2=482 MPa, A =20%, Z=63%.