Classification of Solutions for Stainless Steel Pipe Welding

The pipe making machine produces pipes by using continuous rolling molding until the edge of the strip meets at the welding section. At this point, the welding process melts the edges of the pipe and melts them together.

Process requirements for stainless steel welded pipe:

1. Strong penetration

2. No oxide inclusion

3. Heat impact area is as small as possible

1. Arc welding.

Common seen: Argon TIG welding/plasma welding

In practical scenarios, industrial stainless steel pipe products using argon arc welding are widely used in the health, chemical industry, nuclear industry and food industries.

The argon arc welded stainless steel pipe with tungsten noble gas protection has good adaptability and stability, high welding quality and good permeability

However, the weakness is that the welding speed is relatively not high. In order to improve the welding speed, the bipolar or tripole welding torch is generally used, the welding steel pipe wall thickness is 2mm, the welding speed is 2-4 times higher than the single torch, and the quality is also improved. TIG welding and plasma welding can be welded to a larger steel pipe wall thickness

2. Laser welding

With the limitation of argon arc welding capacity, many pipe machine manufacturers have replaced argon arc welding machine with laser welding machine. Laser welding is fast and has high capacity, with increasing the price of the entire production line for matching mills and annealing furnaces of sufficient quality and equal speed.

3. High frequency welding

Common seen: high frequency electric resistance welding --ERW 

High frequency welding has higher power, faster speed, higher capacity, and is suitable for different materials, with a maximum welding speed of more than 10 times compared to argon arc welding. Difficult to remove burr due to high welding speed. At present, high frequency welded stainless steel pipes are not used in chemical industry and nuclear industry.

4. Combined welding 

Common seen: Argon arc welding with plasma welding, high frequency welding with plasma welding. 

Combination welding is very important to improve the welding speed. The whole welding system is easy to achieve automation, this combination is easy to converge with the existing high frequency welding equipment, low investment cost, good efficiency.