Stainless steel welded pipe production process
In recent years, due to the improvement of production equipment, my country's stainless steel welded pipes have also been greatly improved in terms of variety, quality, output, and specifications.
(1) Forming process of stainless steel welded pipe There are two types of stainless steel welded pipe forming methods: continuous forming and pressure forming. The typical continuous forming stainless steel welded pipe production line is a continuous forming welded pipe unit with a diameter of 630mm imported from Japan by Jiuli Group, which adopts advanced welded pipe forming technology (FFX flexible forming technology) production. Medium and large diameter stainless steel welded pipes (diameter 219～630mm×2～22mm); typical pressure forming stainless steel welded pipe production lines include 820mm diameter UOE forming stainless steel welded pipe units imported from Sweden by Taigang Stainless. In my country's stainless steel welded pipe production lines, there are mostly small and medium-sized units, and the products are mainly decorative pipes and industrial pipes. The forming method generally adopts roll continuous forming.
(2) Welding process of stainless steel welded pipe At present, the stainless steel welding methods used in industry mainly include tungsten argon arc welding (TIG), high frequency welding, plasma welding and laser welding. Several welding methods have their own characteristics, but the most used are argon arc welding and high frequency welding. Tungsten inert gas shielded argon arc welding has high welding quality and good penetration performance. Its products have been widely used in chemical, nuclear and food industries, but its welding speed is not high. In order to improve the welding speed, some foreign companies have researched and developed a variety of methods. Among them, there is a welding method developed from a single electrode and a single torch to a multi-electrode multi-torch welding method, and the multi-torch argon arc welding is suitable for welding austenitic and ferritic stainless steel pipes. High-frequency welding is still a relatively new technology for welding stainless steel pipes. The welding speed is more than 10 times that of argon arc welding, but it is difficult to remove the burrs in the welded pipes. At present, high-frequency welded stainless steel pipes cannot be accepted by the chemical and nuclear industries.
Laser welding technology is the latest welding technology. The welded steel pipe has very small weld seam, high welding quality and fast welding speed. It is suitable for welding high-quality stainless steel pipes. Germany, Japan and other countries have adopted this technology (some domestic enterprises). is also using this technique). Combined welding technology is to combine several welding methods to form a new welding process to meet people's requirements for the quality and production efficiency of stainless steel welded pipes. Japan, France and other countries have used certain combined welding technology for stainless steel welded pipe production.