1results about How to "Reduce waviness" patented technology

A zinc-based high-strength outer sheet with excellent formability and equipped with a GI or ZM coating, and its manufacturing method, are disclosed. The chemical composition of the steel, by mass percentage, is as follows: C: 0.04%–0.1%, Si: 0.2%–0.5%, Mn: 1.2%–1.8%, P≤0.02%, S≤0.01%, Al: 0.02%–0.05%, Cr≤0.5%, Nb≤0.02%, N≤0.006%, with the balance being Fe and unavoidable impurities. The content of Si, Mn, and Cr satisfies the condition: (Mn+Cr)−2×Si≥0.5%. This method, through optimized composition design and precise control of the annealing-galvanizing process, synergistically solves the core contradiction of achieving high strength, high formability, and high surface quality in high-strength outer sheets. In particular, it effectively inhibits surface oxidation of the substrate, ensuring the uniformity, density, and adhesion of the coating, and can stably produce high-quality outer sheet products suitable for pure zinc (GI) and zinc-aluminum-magnesium (ZM) coatings.