Description

Among the hot-dip galvanized products, through post-treatment by heat diffusion, alloyed galvanized sheets have been developed. The corrosion resistance of these sheets has been increased by more than double compared to ordinary hot-dip galvanized sheets. This alloying treatment can eliminate the zinc granules on the surface of the coating; at the same time, it reduces the evaporation of zinc during spot welding, lowers the degree of contamination of the copper electrodes of the spot welding machine by zinc vapor, and thereby increases the lifespan of the electrodes. To ensure the good adhesion of the coating of the alloyed galvanized sheets, for the thicker alloyed galvanized sheets used in automotive outer panels, efficient heating and cooling measures (high-efficiency burners or induction heaters) were adopted, and various types of alloying sensors were equipped. Through instrument analysis and computer instructions, the corresponding structures in the coating were adjusted in a timely manner to produce products that meet the requirements of high stamping deformation.