Circular seam welding method for stainless steel gas cylinder liner

The invention discloses a circular seam welding method for a stainless steel gas cylinder liner. The circular seam welding method comprises the following steps: firstly, putting a secondary shrinkage mouth into a liner barrel body; then, applying acting force to a front end enclosure component and a rear end enclosure component, so that the primary shrinkage mouth completely enters the liner barrel body and is in interference fit with the liner barrel body; after butt assembly is ended, clamping the liner barrel body and introducing mixed protective gas on a welding gun, introducing high-purity argon protective gas on a welding gun pulling cover, and carrying out metal inert-gas arc welding MIG on a liner circular seam; and after the welding is completed, delaying the protective gas on the welding gun pulling cover by 5-10 seconds, and then, closing equipment, thereby completing welding. According to the circular seam welding method, by carrying out primary shrinkage and secondary shrinkage on end enclosure components, a base plate structure is not adopted in a liner barrel body butt-assembly process, so that the butt assembly is easy, the operation is simple, the working strength is reduced and the working efficiency is improved. By adopting the circular seam welding method disclosed by the invention, a nondestructive testing qualified rate is higher than 99%, and the physical and chemical test project completely meets the standard requirements.