Galvanized coil is a metallic material featuring a zinc layer adhered to the surface of thin steel sheets through a continuous galvanizing process; its primary constituents are steel and zinc alloys. It is broadly categorized into two types: regular galvanized steel sheets and alloyed galvanized steel sheets. China stands as the world's largest producer of hot-dip galvanized coils, maintaining an annual output of approximately 90 million tons. Galvanized sheets are predominantly utilized in the construction industry, home appliance manufacturing, automotive production, and light industry sectors.
With the increasing market penetration of new energy vehicles (NEVs), the demand for galvanized sheets within this sector has witnessed significant growth, with its share of total demand projected to reach 11.58% by October 2025. The production process involves immersing coiled steel sheets into a bath of molten zinc. For alloyed variants, the material undergoes a post-immersion heating treatment at 500°C to form a zinc-iron alloy layer, which offers superior advantages in terms of paint adhesion and weldability. Production operations incorporate advanced technologies-such as dross-skimming robots and zinc coating thickness gauges-to ensure consistent product quality.
Based on performance characteristics, these products are classified into seven distinct grades, including those for general use, mechanical interlocking, and deep drawing applications; the base substrate typically consists of cold-rolled coils or hot-rolled, acid-pickled coils. Regarding the coating structure, galvanized sheets are categorized into four types based on their "spangle" pattern: normal spangle, minimized spangle, zero spangle, and zinc-iron alloy. Furthermore, specific codes-ranging from Z60 to Z600-are assigned to designate the weight of the zinc coating applied to both sides of the sheet.