Specification Distinction

“C” is added to the specifications of the coil, for example: 2.75*1500*C is the coil, 2.75*1500*6000 is the steel sheet.

The meaning of the numbers in the coil specifications: 2.75 represents the thickness of the coil, 1500 represents the width of the coil, and “C” represents the coil.

The meaning of the numbers in the steel plate model specifications: 2.75 represents the thickness of the steel sheet, 1500 represents the width of the steel sheet, and 6000 represents the length of the steel sheet.

1.Appearance difference

The surface of electro-galvanized steel is smooth, dense, beautiful and shiny without zinc flower.

The surface of the hot-dip galvanized steel is uneven, rough and uneven, shiny and white. Some products have zinc flowers and knocking may cause the zinc-iron alloy layer to fall off in small pieces.

 

2.Application range difference

Electro-galvanized is suitable for small parts.

Hot dip galvanizing is more suitable for large parts.

 

3.Zinc coating thickness and weight difference

The thickness of the electroplated zinc layer is about 10um, the zinc layer is thin, and the adhesion is weak; the minimum galvanized amount is 15g / m2 and the maximum is 100g / m2.

The thickness of the hot-dip galvanized zinc layer is about 60um, the zinc layer is thick, the adhesion is strong, and the zinc layer is not easy to fall off; the minimum amount of galvanizing is 40-60g / m2 on both sides and the maximum is 600g g / m2.

 

4.Corrosion resistance and zinc coating structure difference

Galvanized zinc has poor corrosion resistance compared to hot-dip galvanized and is suitable for indoor use. The zinc atoms of the electroplated zinc layer are only deposited on the surface of the metal parts and adhere to the surface of the steel strip by physical action. There are many pores, which are easy to cause pitting corrosion due to corrosive media.

Hot-dip galvanizing is more corrosion resistant than electro-galvanizing and suitable for outdoor use. There is a slightly brittle compound layer between the pure zinc coating of the hot-dip galvanized sheet and the steel strip substrate. When the pure zinc coating crystallizes, zinc flower is formed, and the coating is uniform and non-porous.

 

5.Cost difference

The price of small parts of electrogalvanized zinc is low, and the price of large parts is high. The process of zinc coating for large parts of electro-galvanized zinc is complicated, the speed of zinc coating is slow, the cost increases more, and it is not economical.

The price of hot-dip galvanized small parts is high and the price of large parts is low. Hot-dip galvanizing has a fast galvanizing speed and a large amount of hot-dip galvanizing.

 

6.Different degrees of environmental pollution

Galvanized zinc has great environmental pollution, while hot-dip galvanizing has little environmental pollution

 

7.Processing performance difference

The processing performance of electro-galvanized parts is good: electro-galvanized sheet uses cold-rolled sheet as raw material, which basically guarantees the same processing performance of cold-rolled sheet.

The processing performance of hot-dip galvanized parts is not as good as that of electro-galvanized parts: the heat treatment process of hot-dip galvanized and electro-galvanized sheets is also completely different. The steel strip is heated and cooled in a short time, so the strength and plasticity are affected to a certain extent.
 

1. Resistance to atmospheric corrosion: GL(galvalume) steel sheet is excellent, while GI(galvanized) steel sheet is good.

 

2. High temperature oxidation resistance:GL sheet is excellent, and GI is good.

 

3. Processing performance: GL sheet behaves well, and GI behaves well.

 

4. Weldability: GL sheet behaves poorly, while GI behaves better.

 

5. Coating property: GL sheet behaves better, and GI behaves better.

 

6. Incision protection: GL sheet behaves poorly, while GI behaves better.

 

7. Cathodic protection: GL sheet is poor, while GI is strong.

Naming method

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.

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.
 

Galvanized Steel Sheet

Galvanized steel sheet is coated with a layer of metallic zinc on the surface of the steel sheet to prevent corrosion of the steel sheet surface and prolong its service life. This kind of zinc-coated thin steel sheet is called galvanized sheet. Galvanized steel strip products are mainly used in construction, light industry, automobile, agriculture, animal husbandry, fishery and commerce. Among them, the construction industry is mainly used to manufacture anti-corrosion industrial and civil building roof panels, roof grilles, etc .; the light industry industry uses it to manufacture household appliance shells, civil chimneys, kitchen appliances, etc., and the automotive industry is mainly used to manufacture corrosion-resistant parts of cars ; Agriculture, animal husbandry and fishery are mainly used as food storage and transportation, meat and aquatic products frozen processing equipment, etc .; commerce is mainly used as storage and transportation of materials, packaging equipment, etc.

 

Stainless Steel Sheet

Stainless steel refers to steel that is resistant to weak corrosive media such as air, steam, water, and chemically aggressive media such as acids, alkalis, and salts. It is also known as stainless acid-resistant steel. In practical applications, steel that is resistant to corrosion by weak media is often called stainless steel, and steel that is resistant to chemical media is called acid-resistant steel. Stainless steel is often divided into martensite steel, ferritic steel, austenitic steel, austenitic-ferrite (dual phase) stainless steel, precipitation hardening stainless steel, etc. In addition, it can be divided into: chromium stainless steel, chromium nickel stainless steel, chromium manganese nitrogen stainless steel and so on. The corrosion resistance of stainless steel decreases with the increase of carbon content. Therefore, the carbon content of most stainless steels is low, generally not more than 1.2%, and the Wc (carbon content) of some steels is even less than 0.03% (such as 00Cr12 ). The main alloy element in stainless steel is Cr (chromium). Only when the Cr content reaches a certain value, the steel has corrosion resistance. Therefore, the general Cr (chromium) content of stainless steel is at least 10.5%. Stainless steel also contains Ni, Ti, Mn, N, Nb, Mo, Si and other elements.