3results about How to "Improve Platability" patented technology

This invention relates to the field of metallurgical technology and proposes a method for preparing continuously hot-dip galvanized steel strip, comprising the following steps: molten iron pretreatment, smelting, refining, hot rolling, and cold rolling to obtain a steel strip substrate; electrolytic cleaning of the steel strip substrate, annealing followed by hot-dip galvanizing treatment, cooling, and post-treatment to obtain hot-dip galvanized steel strip; the steel strip substrate is composed of the following components by mass percentage: C 0.09%~0.12%, Mn 0.9%~1.15%, Al 0.03%~0.05%, B 0.004%~0.005%, Nb 0.02%~0.04%, Si≤0.01%, Ca 0.003%~0.005%, Yb 0.001%~0.003%, with the balance being Fe and other unavoidable impurities. This technical solution solves the problem of poor corrosion resistance and mechanical properties of existing galvanized steel strips.

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.

A flexible post-processing production line for cold-rolled strip steel suitable for producing various high-strength steels includes the following stations in sequence: uncoiling – welding – inlet looper – cleaning – central continuous post-processing – intermediate looper – leveling – outlet looper – finishing – coiling. The central continuous post-processing station includes, in sequence: a jet radiant tube preheating section, a radiant tube heating section, a transverse magnetic induction heating section or a jet radiant composite heating section, a jet radiant composite homogenizing section, a slow cooling section, a rapid cooling section, a reheating section, parallel sections (furnace nose section + zinc pot section + air knife section + alloying heating section + alloying homogenizing section + post-plating cooling section) and (moving channel section + over-aging section + final jet cooling section), a final water cooling section, and optional pickling and flash plating sections. This invention can produce five varieties of ultra-high-strength strip steel products—cold-rolled annealed, pickled, flash-plated, hot-dip pure zinc, and alloyed hot-dip galvanized—on the same production line.