Principle of pickling iron strap

The raw material of iron strapping is hot-rolled steel strip. The surface of the hot-rolled steel strip will have hard and brittle scales. The oxide scale layer is produced during high-temperature rolling. Pickling is a process we will perform during the processing of steel strips. This process is usually carried out before cold rolling. The main purpose is to remove the oxide scale on the surface of the steel strip. In addition to iron oxide scale, it also contains elements such as P, Mn, Si, S and C. These oxides are harmful to cold rolling. If these steel strips with oxide scales are directly placed in a cold rolling mill for rolling, the following effects will be produced: under high pressure, the converted oxide scales are pressed into the strip steel matrix, thereby affecting the surface quality. Moreover, the workability of cold-rolled steel strips may even cause waste. After the iron sheet is broken, it enters the cold rolling emulsion system to reduce the pollution of the emulsion, change the replacement amount of the emulsion, damage the surface of the damaged roll, and adversely affect the surface quality of the iron strap. This method is a chemical method that uses strong acids such as sulfuric acid, hydrochloric acid, nitric acid and hydrofluoric acid to chemically react with iron and phosphorus on the steel surface to remove oxide scale. Nitric acid and hydrofluoric acid are mainly used for pickling stainless steel.