The selection of the welding method for stainless steel industrial pipes should be selected according to the material and wall thickness of stainless steel industrial pipes. Different welding methods have different characteristics because of different welding methods with different arc heat and arc forces. For example, tungsten argon arc welding is characterized by low current density, stable arc combustion, good weld formation, especially suitable for thin plate welding, and thick plate welding is not preferred; plasma arc is characterized by high arc column temperature and energy density. Large, plasma arc has good straightness, its rigidity and flexibility have a wide adjustment range, and the work is stable, but the operation is more complicated; submerged arc welding has the characteristics of deep penetration ability and high efficiency of welding wire, so welding The speed can be greatly improved, the welding cost is low, but the working conditions and environment are relatively poor. It can be seen that different welding methods have different capabilities and different operating costs. According to the material and wall thickness of the stainless steel industrial pipe, the reasonable selection of the welding method is a very important task to ensure the welding quality, increase the productivity and reduce the cost.
In addition, the same welding method, the type and size of the welding current, the arc voltage, the welding speed, and the welding materials used have a great influence on the arc heat and the arc force. Therefore, different welding methods can only be applied to welding of different materials and thicknesses. The following figure shows the different welding methods for stainless steel welding speed ranges of different thicknesses.
Welding method for stainless steel industrial pipe
The selection of welding methods for stainless steel industrial pipes and the determination of process parameters should be based on the material and wall thickness, and efforts should be made to meet the following requirements:
- Ensure that the welding quality meets the requirements of relevant standards;
- The welding process should be stable and reliable (less faults and welding defects);
- The welding speed should be fast, that is, the production efficiency should be high;
- Welding costs and consumption are the lowest.
As can be seen from the above figure, tungsten argon arc (TIG) filler wire welding, stainless steel industrial pipe thickness between 0.2mm-4.5mm, speed between 10cm/min-100cm/min.
TIG welding, TIG welding stainless steel industrial pipe thickness between 0.2mm-5.5mm, speed between 10cm/min-150cm/min.
MIG, the thickness of the weldable stainless steel industrial pipe is between 2.0mm and 6.5mm and the speed is between 35cm/min and 110cm/min.
Plasma arc welding (PAW), weldable stainless steel industrial pipe thickness between 2.0mm-8.0mm, speed between 10cm/min-90cm/min.
Because all welding methods have their maximum output energy limit, its weldable thickness is also limited. Therefore, it can be flexibly selected according to thickness and production practice, such as combination welding of various welding methods.
Stainless steel industrial pipe thickness between 0.5mm-4.0mm, can be TIG welding (only for strip continuous forming welding unit); thickness ≧ 2mm, can also be used PAW welding (suitable for strip continuous forming welding unit and discontinuous Welding unit)
Stainless steel industrial pipe thickness between 1.5mm-4.0mm, can also be used multi-cathode TIG welding (suitable for strip continuous forming welding unit);
Stainless steel industrial pipe thickness between 4.0mm-8.0mm, can be welded once by PAW welding (suitable for strip continuous forming welding unit);
Stainless steel industrial pipe thickness ≧ 8.0mm, can be covered by PAW welding and other welding methods, such as TIG welding cover, SAW welding surface, flux cored wire welding cover (for non-continuous welding units).
In addition, the use of laser welding for the welding of stainless steel industrial pipes is also a development direction of stainless steel welded pipes.
Source: China Industrial Pipes Manufacturer – Yaang Pipe Industry Co., Limited (www.yaang.com)