Abstract: Deep Penetration TIG welding (DP-TIG welding) takes the advantage of deep penetration welding and has great advantages in the field of thick plate welding. In order to expand applications of DP-TIG welding in the field of high-speed welding of thin plates, the high-speed welding process of thin plates made of low carbon steel and stainless steel was investigated in this research by adjusting welding current, welding speed, tungsten cone angle, gas composition and other process parameters. The experimental results show that compared with conventional TIG welding, the welding speed of low carbon steel plate with 2 mm thickness is increased by 75%, and for stainless steel plate with 3 mm thickness, the welding speed is increased by more than 2 times. Moreover, with the decrease of tungsten electrode angle, the welding speed can be further improved. If a certain amount of H₂ is introduced into the shielding gas, the maximum welding speed of stainless steel DP-TIG welding may be improved further to a certain extend.

Key words: stainless steel, low carbon steel, DP-TIG high-speed welding, angle of tungsten electrode, component of shielding gas