Stainless steel pipe welding points and precautions

1. The power supply with vertical external characteristics is adopted, and the positive polarity is used for DC (the welding wire is connected to the negative pole)
2. Generally suitable for welding thin plates below 6mm, with the characteristics of beautiful weld shape and small welding deformation
3. The protective gas is argon with a purity of 99.99%. When the welding current is 50~150A, the flow rate of argon gas is 8~10L/min, when the current is 150~250A, the flow rate of argon gas is 12~15L/min.
4. The protruding length of the tungsten electrode from the gas nozzle is preferably 4~5mm. It is 2~3mm in places with poor shielding such as fillet welding, and it is 5~6mm in places where the slot is deep. The distance from the nozzle to the work is generally not more than 15mm.
5. To prevent the appearance of welding pores, if there are rust and oil stains on the welding parts, they must be cleaned.
6. The welding arc length is preferably 2~4mm when welding ordinary steel, and 1~3mm when welding stainless steel pipe. If it is too long, the protection effect will not be good.
7. When butt bottoming, to prevent the back of the bottom weld bead from being oxidized, the back also needs to be protected by gas.
8. To make the argon gas well protect the welding pool and facilitate the welding operation, the center line of the tungsten electrode and the workpiece at the welding place should generally maintain an angle of 80~85°, and the angle between the filler wire and the surface of the workpiece should be as small as possible. Generally, it is about 10°.
9. Windproof and ventilation. Where there is wind, please take measures to block the net, and take appropriate ventilation measures indoors.