How to extend the service life of 304 stainless steel pipe

Laser welding of 304 stainless steel tube welding method In recent years, due to increasing attention to environmental issues, auto manufacturers are increasingly under pressure to improve fuel efficiency. Tighter and more restrictive regulations have brought technical challenges to industrial production and material processing. Among these trends are reduced exhaust emissions, lighter bodywork, and extended component life.

Advances in material processing have brought unique opportunities to the field of stainless steel pipe production. Specifically, people are required to produce such parts. They must have a lighter weight, but they must still have anti-corrosion characteristics and meet strength requirements. In addition, the space limitations of the body emphasize the importance of formability. Typical applications include exhaust pipes, fuel pipes, fuel injection nozzles and other components.

When forming a stainless steel tube, a flat steel strip is formed first, and then its shape becomes a round tube. Once formed, the seams of the stainless steel pipes must be welded together. This weld greatly affects the formability of the part. Therefore, to obtain a welding profile that can meet the strict testing requirements in the manufacturing industry, it is extremely important to choose the appropriate welding technology. There is no doubt that tungsten gas shielded arc welding (GTAW), high frequency (HF) welding, and laser welding have been used in the manufacture of stainless steel pipes.

  Laser welding

In all 304 stainless steel pipe welding applications, the edges of the steel strip are melted. When the edges of the stainless steel welded pipe are squeezed together using a clamping bracket, the edges solidify. However, the characteristic of laser welding is its high energy beam density. The laser beam not only melted the surface layer of the material, but also created a keyhole, so that the shape of the weld was very narrow.

If the power density is less than 1MW / cm2, such as GTAW technology, it will not produce enough energy density to generate the keyhole. In this way, the welding outline obtained by the keyhole-free process is wide and shallow. The high precision of laser welding brings higher efficiency penetration, which in turn reduces grain growth and brings better metallographic quality; on the other hand, GTAW's higher heat input and slower cooling process result Rough welded structure.