Introduction of galvanized sheet production line

In Tabriz Shahriar Steel Industry Company, galvanized sheet is produced by continuous hot dip method, the merits of the above method compared to other methods include cost-effectiveness, the possibility of creating controlled and requested thicknesses, as well as strength and High adhesion of galvanized coating. The incoming rolls from the raw material warehouse at the beginning of the line are opened using roll opening machines and after cutting the beginning and end of the sheet, they are welded together and enter the production line as a continuous strip. In the first step, the galvanized sheet passes through the washing part, which contains alkaline substances, and the surface of the sheet is cleaned during the stages of degreasing, brushing and washing with hot water. Further along the path, the sheet passes through the acid washing part and all the oxides on the sheet are destroyed, and after passing through the flux tank, it enters the preheated furnaces and is ready to enter the molten zinc (Zn) bath. After passing through the molten zinc bath, a thin layer of zinc metal is deposited on both surfaces of the sheet. Immediately after leaving the molten bath, the thickness of the zinc metal coated on the sheet surfaces is adjusted by the air jet. In the cooling stage of the sheet, before entering the water tank and bringing it to the ambient temperature, the temperature of the sheet is reduced by blowing air and then it is cooled by immersion in hardened water. At the end, hot air dries the sheet completely. The thickness of the coated zinc metal on the sheet surfaces is controlled by a thickness gauge. In the next step, after the sheet dries, the chemical chromating process is performed. This operation protects the surface of the galvanized sheet against moisture and reduces the risk of forming white scale on the surface of the sheet. At the end of the line, after the necessary inspections, the continuous sheet is cut by scissors and rolled into coils in different tonnages according to the customer's needs and orders, and after packaging, it is offered to the consumer market. In the different stages of production and after the completion of the production process, sampling is done continuously by the quality control department and the necessary checks are done in the laboratory.