The channel steel of steel wholesale companies is divided into ordinary channel steel and light channel steel. The specifications of hot-rolled ordinary channel steel are 5-40 #. The specifications of hot-rolled flexible channel steel supplied through agreement between the supply and demand parties are 6.5-30 #. Channel steel can be divided into four types according to its shape: cold-formed equal edge channel steel, cold-formed unequal edge channel steel, cold-formed inner rolled edge channel steel, and cold-formed outer rolled edge channel steel. The material of the channel steel is Q235A carbon steel. Channel steel is mainly used in building structures, curtain wall engineering, mechanical equipment, vehicle manufacturing, fixed cabinets, and other industrial structures. Channel steel is often used in conjunction with I-beams. In use, it is required to have good welding, riveting performance, and comprehensive mechanical properties.
Hot dip galvanized channel steel can be divided into hot-dip galvanized channel steel and hot-blown galvanized channel steel according to different galvanizing processes. It involves immersing the derusted steel parts in molten zinc at around 440~460 ℃ to attach a zinc layer to the surface of the steel components, thereby achieving the purpose of corrosion prevention.
The process flow of galvanized channel steel: raw material inspection → acid washing → cleaning → zinc assistance → drying → galvanizing → cooling → passivation → cleaning → finished product inspection → inspection and packaging, etc.
According to customs, hot-dip galvanizing processes are often divided into two categories based on different pre-treatment methods: offline annealing and online annealing.
Off line annealing refers to the recrystallization annealing of hot-rolled or cold-rolled steel in a bottomed annealing furnace or bell type annealing furnace before entering the hot-dip galvanizing line. In this way, there is no annealing process in the galvanizing line. Before hot-dip galvanizing, steel must maintain a clean, pure iron active surface free of oxides and other dirt. This method involves first removing the annealed surface iron oxide scale by acid washing, and then applying a layer of zinc chloride or a solvent composed of ammonium chloride and zinc chloride for protection to prevent the steel from being oxidized again. In line annealing refers to the gas protected recrystallization annealing of hot-dip galvanized raw plates directly provided by the cold rolling or hot rolling workshop as coils