Production of stainless steel pipe

The stainless steel seamless pipe can be produced by hot rolling, hot extrusion, cold rolling and cold drawing. In recent years, due to the advancement of continuous casting and rolling technology and the application of various new welding technologies and non-destructive testing technologies, the quality of stainless steel welded pipes has been continuously improved, and stainless steel seamless pipes can be partially replaced in various fields of use, and the price is more than that of seamless pipes. 20% lower. Currently, stainless steel pipes in industrial applications account for 50% of welded pipes and seamless pipes.

The cut stainless steel welded pipe is divided into the following three cases according to the product use:

(1) The welded pipe that does not need heat treatment and drawing is straightened, flat, and water-pressured, one inspection, one package, one storage; (2) the welded pipe that needs heat treatment is degreased, one bright heat treatment, one straightening, one ultrasonic inspection, one flat head, one water pressure (1) The welded pipe that needs to be drawn is degreased, the forged tip is annealed, the straightened one is pickled, the other is lubricated, the other is pulled, the first one is degreased, the other is bright, the other is the first Library

The new technology of stainless steel welded pipe has multiple torches using multiple electrodes (generally three electrodes), and it can also be a combination of argon arc welding and plasma welding. Multi-torch welding is suitable for welded pipes with wall thickness greater than 2mm. The welding speed is 3~4 times higher than that of single torch, and the welding quality is also improved. In addition, adding 5% to 10% of hydrogen in argon, and then using high-frequency pulse welding power supply, can improve the welding speed; to ensure the welding quality, the welding torch is automatically tracked by the welding device, and the arc voltage automatic control system (AVC) ), computer controlled welding process, etc. The methods for removing the inner welding thorn are as follows: (1) the inner wall air supporting technology, the inner wall is filled with a certain pressure of inert gas to hold the molten liquid droplets, so that it does not sag, so that no welding spurs are formed; (2) inner wall hammering technology For φ30mm or less pipe; (3) Inner wall rolling technology, suitable for φ50mm or more welded pipe; decorative pipe should be equipped with high-efficiency grinding and polishing equipment to improve the smoothness of the surface of stainless welded pipe.