Common grades of galvanized steel sheet are DX51D + Z, DX52D + Z, DC51D + Z, DC52D + Z, S350GD + Z, etc. The galvanized steel sheet or steel plate grade is composed of five parts: product use code, steel grade code, steel type characteristics, hot-dip galvanized code (D), +, and general coating code.
1.Galvanized sheet for cold forming
Examples of grades: DX51D Z (or ZF AZ), DC51D Z (or ZF AZ), DD52D Z (or ZF AZ) DX: The first letter D means flat steel for cold forming, and the second letter if it is X , Indicating that the rolling state of the substrate is not specified; if the second letter is C, the substrate is specified as a cold-rolled substrate; if the second letter is D, it means that the substrate is specified as a hot-rolled substrate; 51 ~ 57: two digit Indicates the steel grade serial number; a D after the two digits is the code for hot-dip galvanizing; Z indicates that the coating is pure zinc, ZF indicates galvanized iron alloy, and AZ indicates aluminum-zinc plating. Therefore: DX51D Z indicates that the product is used for cold forming, flat steel, the substrate state is not specified, the steel grade serial number is 51, pure zinc coating, hot-plated products.
2.Examples of naming of other galvanized grades
S350GD Z: S indicates structural steel, 350 indicates the specified minimum yield strength is 350Mpa, G indicates that the steel characteristics are not specified, D indicates hot-dip galvanizing, and Z indicates that the coating is zinc.
HX340LAD ZF: indicates that the product is used for cold forming high-strength flat steel, without specifying the state of the substrate, the minimum yield strength is 340Mpa, the steel type is high-strength low-alloy steel, zinc-iron alloy coating, hot-plated products.
HC340 / 590DPD Z: indicates that the product is used for cold forming, high-strength flat steel, the substrate is specified as a cold-rolled substrate, the minimum yield strength is specified as 340Mpa, the minimum tensile strength is specified as 590Mpa, the steel type is dual-phase steel, pure Hot-dip products with zinc coating.
Code for surface quality
Ordinary surface: FA
Higher level surface: FB
Advanced Surface: FC
Coating surface treatment
(1) Chromic acid passivation (C) and chromate-free passivation (C5): This surface treatment can reduce the surface white rust of the product during transportation and storage. When chromium-free passivation treatment, the human health of the passive film squadron should be limited Harmful hexavalent chromium components;
(2) Chromic acid passivation Oil (CO) and chromium-free passivation Oil (CO5): This surface treatment can further reduce white rust on the surface of the product during transportation and storage.
(3) Phosphating (P) and phosphating Oil (PO): This surface treatment can reduce white rust on the surface of the product during transportation and storage, and can improve the formability of the steel plate.
(4) Fingerprint-resistant film (AF) and chrome-free fingerprint-resistant film (AF5): Surface treatment can reduce the white rust of the product during transportation and storage. When chromium-free passivation treatment, passivation film squadron should be limited Hexavalent chromium composition.
(5) Oil coating treatment (O): reduce the generation of white rust during storage and transportation. The anti-rust oil applied is generally not used as rolling oil and stamping lubricant for subsequent processing.
(6) No treatment (U): In this case, the surface of the steel plate and steel belt is prone to form white rust and black spots during transportation and storage and transportation, and users should be careful when selecting.