In the production process of stainless steel welded pipe, intermediate heat treatment and finished heat treatment can be carried out. Because a bright surface without oxidation can be obtained, the traditional pickling process is eliminated. The use of this heat treatment process not only improves the quality of the welded pipe but also overcomes the environmental pollution caused by pickling.
According to the current world development trend, the bright continuous furnaces for stainless steel welded pipes are divided into three types:
1. Roller bottom bright heat treatment furnace. This furnace is suitable for heat treatment of large and batch steel pipes, with an hourly output of more than 1.0t. Shielding gases that can be used are high-purity hydrogen, ammonia, and other shielding gases. A convection system can be provided to rapidly cool the steel pipe.
2. Mesh belt-type bright heat treatment furnace. This type of furnace is suitable for small-diameter thin-walled steel pipes, and the output per hour is about 0.3~1.0t. The treated stainless steel welded pipe can be up to 40 meters in length and can also handle coiled capillaries.
3. Muffle furnace-type bright heat treatment furnace. The steel pipe is installed on a continuous handle frame and heated in a muffle tube, which can process high-quality small-diameter thin-walled steel pipes at a lower cost, with an hourly output of about 0.3t or more.
Stainless steel welded pipe requires infiltration, no oxide inclusions, and the heat-affected zone is as small as possible. Tungsten inert gas shielded tungsten argon arc welding has good adaptability, high welding quality, and good penetration performance. The products are widely used in chemical, nuclear, food, and other industries.