Currently, the main welding methods for stainless steel welded pipes used in industry include argon arc welding (argon arc welding), high-frequency welding, plasma welding, and laser welding. Each method has its own characteristics, with argon arc welding and high-frequency welding being the most widely used.
First, Stainless Steel Welded Pipe Process Technology – Argon Arc Welding.
Stainless steel welded pipes require deep penetration, no oxide inclusions, and a minimal heat-affected zone. Tungsten inert gas (TIG) welding offers good adaptability, high weld quality, and good penetration performance, making it widely used in chemical, nuclear, and food industries. The relatively low welding speed is a drawback of TIG welding. To improve welding speed, a three-electrode torch is generally used. For pipe wall thicknesses S≥2mm, the welding speed is 3-4 times higher than with a single torch, and the weld quality is also improved. Combining TIG welding with plasma welding allows for welding pipes with even thicker walls. Furthermore, adding 5-10% hydrogen to the argon gas and using a high-frequency pulse welding power source can also increase the welding speed.
Second, Stainless Steel Welded Pipe Technology – High-Frequency Welding.
High-frequency welding boasts high power output, enabling high welding speeds for steel pipes of varying materials, outer diameters, and wall thicknesses. Compared to argon arc welding, its welding speed is more than 10 times faster. Therefore, it offers high productivity in producing general-purpose stainless steel pipes. However, the high welding speed makes burr removal from the welded steel pipe difficult. Currently, high-frequency welded stainless steel pipes are not widely accepted in the chemical and nuclear industries, which is one reason for this. In terms of welding materials, high-frequency welding can weld various types of austenitic stainless steel pipes. Furthermore, the development of new steel grades and advancements in forming and welding methods have also successfully welded ferritic stainless steel grades such as AISI 409.
Third, Stainless Steel Welded Pipe Technology – Combined Welding Technology.
Combined welding methods include: argon arc welding plus plasma welding, high-frequency welding plus plasma welding, high-frequency preheating plus three-torch argon arc welding, and high-frequency preheating plus plasma plus argon arc welding. Combined welding significantly improves welding speed. For welded steel pipes using high-frequency preheating, the weld quality is comparable to that of conventional argon arc welding and plasma welding. The welding operation is simple, the entire welding system is easily automated, and this combination is easily integrated with existing high-frequency welding equipment, resulting in low investment costs and high efficiency.
Various welding methods for stainless steel welded pipes each have their own advantages and disadvantages. The current trend in the development of stainless steel welded pipe technology is to leverage the strengths and mitigate the weaknesses by combining several welding methods to form new welding processes that meet the demands for both quality and production efficiency.
Post time: Dec-09-2025