Brief introduction to the manufacturing skills of spiral steel pipe manufacturers

　　There are many types of steel pipes and different uses, so their technical requirements are different and production methods are different.
　　According to the molding method, the steel pipe can be divided into two categories: thermoformed steel pipe and cold formed steel pipe.
　　Among them, thermoformed steel pipes can be divided into hot rolled steel pipes and hot finished steel pipes. Hot-rolled steel pipe is a hot-milk seamless steel pipe, which comprises a hot extruded pipe which is rolled and extruded at a high temperature, and a hot-expanded tube which is re-extruded by a hot-rolled thick-walled seamless steel pipe and thermally expanded. The unevenness of the speed and temperature of the tube during expansion can result in an uneven increase in the thickness of the tube wall. The hot-finished formed steel pipe is obtained by heat-treating a large-diameter straight welded pipe welded by a curved shape, which can eliminate residual stress and improve plasticity.
　　The cold-formed tube is formed by bending a steel sheet at a normal temperature and then welding it through a weld.
　　For the construction of steel pipe structure, the round pipe and the rectangular pipe can be made of hot milk, hot expanded seamless steel pipe, or straight welded pipe which is formed by roll forming, cold forming and hot forming. The rectangular pipe can also be welded by steel plate. Welding can be done by high frequency welding, automatic welding or semi-automatic welding and manual welding. The welding material should be matched with the base metal.