TIG welding process for battery pack shells and cover plates

The invention discloses a TIG welding process for battery pack shells and cover plates. The process comprises the following steps: (1) workpieces are cleaned; one surfaces of the battery pack shells and one surfaces of the cover plates are firstly brushed by a copper brush, then, are erased by acetone, and are finally dried by compressed air to form battery pack shell cleaned surfaces and cover plate cleaned surfaces; (2) welding parameters are adjusted; the welding current is 50-60 A; the nozzle aperture of a welding gun is 10-13 mm; and the flow of protective gas is 10-15 L/min; (3) the initial welding is performed on four angles formed by back side edges after butt joint of the battery pack shell cleaned surfaces and the cover plate cleaned surfaces; and the initial welding mode is to weld 2-3 welding spots on each of the four angles; and (4) the secondary welding is performed on butt joint gaps formed by the back side edges after butt joint of the battery pack shell cleaned surfaces and the cover plate cl