前言近年来,难熔金属在宇航工程上已获得了日益广泛的应用,它们在制造液体和固体火箭发动机推力室及喷管延伸段上占有重要地位。铌合金为活性金属,其焊接的主要困难是容易被氮、氢、氧有害气体沾污变脆,而且间隙元素对铌合金比钛合金有更大的敏感性和危害性,因而焊接铌合金对焊接工艺的 Introduction In recent years, refractory metals have gained increasingly widespread use in aerospace engineering, and they play an important role in the manufacture of thrust chambers and nozzle extensions of liquid and solid rocket motors. Niobium alloy is the active metal, the main difficulty of welding is easily contaminated by harmful gas of nitrogen, hydrogen and oxygen, brittle, and interstitial elements have greater sensitivity and harm to niobium alloy than titanium alloy, so welding niobium alloy pair Welding process