There are many kinds of cold-formed steel, including open, semi-closed and closed sections. The main products are Cold-Formed Channel steel, angle steel, Z-shaped steel, cold-formed corrugated steel plate, square pipe, rectangular pipe, welded special-shaped steel pipe, rolling shutter door, etc. The cold-formed section steel is usually produced with a thickness of less than 6 mm and a width of less than 500 mm. Commonly used specifications in China include more than 400 specifications and varieties, such as equilateral angle steel (limb length 25-75 mm), inner crimping angle steel (limb length 40-75 mm), channel steel (25-250 mm high), inner crimping channel steel (60-250 mm high), and crimping Z-shaped steel (100-180 mm high). Products are widely used in mining, construction, agricultural machinery, transportation, bridges, petrochemical, light industry, electronics and other industries.
Cold-formed steel is the main material for light steel structure, which is made by cold-formed steel plate or strip. Its wall thickness can not only be very thin, but also greatly simplify the production process and improve production efficiency. It can produce all kinds of profiles with uniform wall thickness but complex cross-section shape and cold-formed profiles of different materials which are difficult to produce by common hot rolling method. Cold-formed steel is widely used not only in various building structures, but also in vehicle manufacturing and agricultural machinery manufacturing. There are many kinds of cold-formed steel, which are separated by section, semi-closed and closed. According to the shape, there are Cold-Formed Channel steel, angle steel, Z-shaped steel, square pipe, rectangular pipe, special-shaped pipe, rolling shutter door, etc. According to GB6725-92, cold-formed section steel is made of common carbon structural steel, high-quality carbon structural steel, low-alloy structural steel plate or steel strip by cold-bending. Cold-formed steel is a kind of economic section steel and energy-saving material. It is a new type of steel with strong vitality. It is widely used in various fields of national economy. Its uses can be divided into highway guardrail, steel structure, automobile, container, steel formwork and scaffold, railway vehicle, ship and scaffold. Bridges, steel sheet piles, transmission towers, and other 10 categories.
In the production of cold-formed hollow rectangular steel, there are two different forming processes. One is to form a circle and then a square or a rectangle; the other is to form a square or a rectangle directly. At present, in the field of square and rectangular steel tube forming, the technology of direct square and moment forming is the most advanced in the world. The technology of directly forming square or rectangle is more advanced than that of first forming circle and then changing square or rectangle. The process of forming circle and then square or rectangle damages the material of steel strip or coil greatly, while the process of forming square and rectangle directly does not destroy the material in the forming process, which can maintain the mechanical and physical properties of raw materials and ensure the excellent product. It is known that a large steel pipe factory in Tai'an, Shandong Province, adopts the technology of direct square and moment forming, and the forming effect is very good.
In recent years, the market demand of cold-formed steel in our country is increasing day by day, the application scope is expanding constantly, and the market prospect is very broad. At present, there is an urgent need to develop cold-formed sections made of stainless steel, galvanized sheet, high strength and ultra-high strength low alloy, as well as ultra-thick and ultra-thin series of high-difficulty and complex cross-section cold-formed steel products.