1) Continuous hot-dip galvanized steel sheet
Continuous hot-dip galvanized steel sheet, abbreviated as galvanized sheet or white iron sheet, is a cold-rolled continuous hot-dip galvanized steel sheet and strip with a thickness of 0.25~2.5mm. The strip is first heated by a flame in a preheating furnace to burn off residual oil on the surface, and at the same time, an iron oxide film is generated on the surface. It is then heated to 710~920 ℃ in a reduction annealing furnace containing a mixture of H2 and N2 gas to reduce the iron oxide film to sponge iron. The surface activated and purified strip steel is cooled to a temperature slightly higher than that of molten zinc, Enter a zinc pot at 450~460 ℃ and use an air knife to control the surface thickness of the zinc layer. Finally, it is passivated by Chromate and dichromate solution to improve white rust resistance.
The surface of the steel plate is beautiful, with block or leaf shaped crystalline patterns, and the coating is firm, with excellent atmospheric corrosion resistance. At the same time, the steel plate also has good welding performance and cold forming performance. Compared to the surface of electroplated zinc plate, its coating is thicker and mainly used for metal parts that require strong corrosion resistance.
Structure classification code: Z-Normal zinc flake: Zinc flake obtained by crystallization at a normal cooling rate, can be used for general purposes: X-small zinc flake: Cooling small zinc flake after finishing treatment, suitable for deep and ultra deep drawing processing and occasions with low surface roughness requirements.
Processing performance codes: PT general purpose, JY mechanical bite, SC deep drawing, CS ultra deep drawing, JY structure.
Zinc layer weight codes: Z100, Z200, Z275; The weight of the galvanized layer refers to the total amount of zinc on both sides of the steel plate, expressed in grams of zinc per square meter of the steel plate (g/m2). For example, Z100 indicates that the zinc content is not less than 100g/m2.
2>Japanese Hot-dip galvanization steel sheet
Applicable grades: SGCC, SGCD1, SGCD2, SGCD3
Zinc layer code: Z12, Z18, Z20, Z22, Z25, Z27
Symbols: S-Steel, G-Cold, 4th position C-common, D-Draw; 1. 2- Stamping grade, 3- Deep drawing grade; Z - Zinc coating (Zine), 12,..., 27- Zinc adhesion × 10g/m2.
3>German Hot-dip galvanization steel sheet
Applicable grades: St01Z, St02Z, St03Z, St04Z, St05Z
Zinc layer code: 100, 180, 200, 275, 350, 450
Symbols: St steel, 01- for general use, 02- for mechanical biting, 03- for Stamping, 04- for deep drawing, 05- for deep drawing; Z-zinc coating (Zine); 100 zinc adhesion (two sided) 100g/m2, 275 zinc adhesion 275h/m2, 350 zinc adhesion 350g/m2.
Surface structure code: Z-use regular zinc flakes, X-small zinc flakes, G-smooth zinc flakes.
Surface treatment code: L-chromate passivation, Y-oil coating, LY chromate passivation with oil coating.
Surface quality code: FA - ordinary grade