采用氩气的TIG焊接法,在工业上已广泛应用,但其热功率低、熔深小,在焊接厚板时不得不采用多层焊,生产率低。而氦弧焊熔深大,甚至超过MIG焊,因而其生产率高(例如日本用氦弧焊焊接75毫米厚的铝合金,只需采用双面单道焊)。再者,氦 TIG welding using argon gas has been widely used industrially but its thermal power is low and its penetration is small. Multi-layer welding has to be used when welding thick plates, resulting in low productivity. However, helium arc welding has a large penetration depth, even higher than that of MIG welding, resulting in high productivity (for example, a 75mm thick aluminum alloy welded by helium arc welding in Japan only requires double-sided single-pass welding). Again, helium