The development of stainless steel pipe welding, steel tube technology and production technology began in the bicycle manufacturing industry. The opening of oil in the early nineteenth Century, the manufacture of ships, steam pot and aircraft in the two world night war era, the production of thermal power boiler after the Second World War of night, the growth of chemical industry and the drilling and transportation of oil and natural gas, all strongly whipping the growth of the variety, production and quality of the steel governor industry. 1. the power supply is vertical, and the polarity is positive when DC is used. It is generally suitable for welding of thin steel pipes below 6mm. It has the characteristics of beautiful weld shape and small deformation of welding. 2. The 3. asylum gas is argon, with a purity of 99.99%. When the welding current is 50~50A, the argon flow rate is 8~0L/min, and when the current is 50~250A, the argon flow rate is 2~5L/min. The length of the 4. tungsten pole from the gas nozzle is the best 4~5mm, and the place where the masking is poor in the angle welding is 2~3mm, and the place where the slotting is deep is 5~6mm, and the distance from the nozzle to the working is generally not across the 5mm. 5.. In order to prevent welding porosity from appearing, rust and oil must be cleaned and cleaned. 6. welding arc length is better than 2~4mm when welding the popular steel. When welding stainless steel, ~3mm is better, too long, and the result of shield is not good. 7. when the bottom is laid, to prevent oxidation of the back of the bottom weld, gas shielding is also needed on the back. 8. in order to protect the welding pool well and facilitate the welding operation, the 80~85 angle of the tungsten middle line and the welding part should be connected. The angle between the filler wire and the workpiece should be as small as possible, and generally 0 degrees. 9. wind and air change. Where there is a wind, please adopt the way of blocking the net, while indoors should adopt the appropriate ventilation.