减少热输入对TIG自熔焊Ti-6Al-4V合金的影响  

Effect of reducing heat input on autogenous TIG welding of Ti-6Al-4V alloy

作　　者：Kamlesh KUMAR Manoj MASANTA 

机构地区：[1]Department of Mechanical Engineering,National Institute of Technology Rourkela,Rourkela 769008,India

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第12期3712-3724,共13页中国有色金属学报（英文版）

摘　　要：采用带有气体保护装置的TIG自熔焊技术以对接接头结构形式焊接厚度为3 mm的Ti-6Al-4V合金板。在适当热输入条件下获得完全熔透的焊接接头后,结合较高焊接电流和扫描速度以减少热输入开展后续实验。对不同热输入条件下获得的焊接接头进行深入的显微组织分析。结果表明,显微硬度、拉伸强度和断裂强度之间存在强相关性。采用较低的热输入可以显著提高焊接接头的力学性能。这是由于在较低热输入条件下,热输入的变化导致初生α相、初生β相和马氏体α相发生改变,从而改善了焊接接头的力学性能。随着热输入从0.406 k J/mm降低到0.232k J/mm,焊接接头的拉伸强度和断裂强度分别从1020和1015 MPa增加到1070和1950MPa。在最小热输入(0.232k J/mm)的情况下,接头的拉伸强度达到基材的98%。实验结果证明在低热输入条件下TIG焊焊接Ti-6Al-4V合金的潜力。3 mm-thick Ti-6Al-4V alloy plates were welded in butt joint configuration through autogenous TIG welding method using a trailing gas shielding arrangement.After attaining full penetrated weld joint with appropriate heat input,subsequent experiments were conducted by reducing the heat input,which was obtained through combination of higher welding current and scan speed.An in-depth microstructural analysis of the weld joint executed under different heat input conditions shows a strong correlation with the microhardness,tensile strength,and flexural strength of the weld joint.A significant improvement in the mechanical properties of the weld joint was perceived for employing lower heat input.Alteration in the primary-α,primary-β,and martensite-α phases,due to the variation in heat input,amended the mechanical properties of the weld joint under lower heat input condition.With the reduction of heat input from 0.406 to 0.232 kJ/mm,the tensile and flexural strengths of the weld joint increased from 1020 to 1070 MPa,and from 1015 to 1950 MPa,respectively.The tensile strength of the joint reached up to 98% of the base material at minimum heat input(0.232 kJ/mm).The experimental results show the potential of TIG welding for joining Ti-6Al-4V alloy under low heat input condition.

关 键 词：TIG焊 TI-6AL-4V合金 热输入 拉伸强度 显微组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]