Brief introduction
Steel materials, which are widely used in industry, will be corroded to varying degrees when used in the environment of atmosphere, seawater, soil and building materials. According to statistics, the annual loss of steel materials due to corrosion in the world accounts for about 1 / 3 of its total output. In order to ensure the normal use of iron and steel products and prolong their service life, the anti-corrosion protection technology of iron and steel has been widely valued by people.
Hot dip galvanizing is one of the most effective means to delay the environmental corrosion of iron and steel materials. It is to immerse the cleaned and activated iron and steel products in molten zinc solution, and coat the surface of iron and steel products with zinc alloy coating with good adhesion through the reaction and diffusion between iron and zinc. Compared with other metal protection methods, the hot-dip galvanizing process has incomparable advantages in the protection characteristics of the combination of physical barrier and electrochemical protection of the coating, the bonding strength between the coating and the substrate, the compactness, durability, maintenance free and economy of the coating, and its adaptability to the shape and size of the product. At present, hot-dip galvanizing products mainly include steel plate, steel strip, steel wire and steel pipe, among which hot-dip galvanizing steel plate accounts for the largest proportion. For a long time, hot-dip galvanizing process has been favored by people because of its low plating cost, excellent protection characteristics and beautiful appearance. It is widely used in the fields of automobile, construction, household appliances, chemical industry, machinery, petroleum, metallurgy, light industry, transportation, electric power, aviation and marine engineering.
This photo shows our zero pangle hot dipped galvanized steel coil.
We are China hot dipped galvanized steel coil supplier.
Specifications of hot dipped galvanized steel coil
Below are detailed tables for China Hot Dipped Galvanized Steel Coil including size specifications, technical requirements, and Chinese manufacturing standards.
Size Specifications for Hot Dipped Galvanized Steel Coil
Specification | Details |
---|---|
Thickness | 0.12 mm - 4.0 mm |
Width | 600 mm - 1500 mm |
Coil Weight | 3 - 25 tons |
Inner Diameter | 508 mm / 610 mm |
Outer Diameter | Up to 2000 mm |
Zinc Coating Weight | Z40 - Z600 (40 g/m² to 600 g/m²) |
Coil Length | Customizable based on requirements |
Technical Requirements for Hot Dipped Galvanized Steel Coil
Technical Property | Typical Values |
---|---|
Zinc Coating Thickness | 40 g/m² to 600 g/m² |
Yield Strength | 195 - 550 MPa |
Tensile Strength | 270 - 700 MPa |
Elongation | Min. 18% for thickness < 0.7 mm, Min. 22% for thickness ≥ 0.7 mm |
Surface Finish | Regular spangle, minimized spangle, zero spangle |
Coating Adhesion | No peeling, blistering, or cracking during bending or drawing tests |
Surface Treatment | Chromated, Oiled, Phosphate, Passivated, Anti-fingerprint |
Flatness | ≤ 8 mm per meter |
Corrosion Resistance | Excellent (rust protection, salt spray testing) |
Formability | Good formability for bending, drawing, and stamping |
Chinese Manufacturing Standards for Hot Dipped Galvanized Steel Coil
Standard Code | Description |
---|---|
GB/T 2518 | Chinese National Standard for hot-dip galvanized steel sheet and strip |
GB/T 708 | Standard for dimensional tolerance of flat rolled products |
GB/T 2975 | Methods for mechanical testing of metals (tensile strength, elongation) |
GB/T 24187 | Surface quality standards for hot-dip zinc-coated steel |
GB/T 6739 | Paint and coating adhesion test method for zinc-coated steel surfaces |
GB/T 13448 | Testing methods for corrosion resistance (salt spray testing) |
GB/T 13912 | Galvanized coating protection standards for steel structures |
ISO 9001 | Quality management standards for manufacturing processes |
Summary of Key Specifications and Standards:
Thickness: From 0.12 mm to 4.0 mm, accommodating a wide range of applications.
Zinc Coating: Z40 to Z600, offering various levels of corrosion protection.
Mechanical Properties: Tensile strength between 270 MPa and 700 MPa, suitable for construction, automotive, and appliance industries.
Surface Treatment: Options like chromating, oiling, or anti-fingerprint to meet specific project needs.
Manufacturing Standards: GB/T 2518 and other Chinese standards ensure product quality in terms of coating adhesion, corrosion resistance, and mechanical properties.
This data can be helpful in understanding the key aspects of China Hot Dipped Galvanized Steel Coils, ensuring product quality and compliance with international and Chinese manufacturing standards.
Process introduction
The principle of hot-dip galvanizing is simply to immerse the cleaned iron parts into the zinc bath through the wetting effect of the plating aid, so that the steel reacts with the molten zinc to form an alloyed film. Good hot-dip galvanizing operation should be that all processes are under strict control and give full play to the function of the process. Moreover, if the operation of the previous process is not good, it will cause chain adverse reactions of the subsequent process, which will greatly increase the operation cost or cause bad hot-dip galvanized products. If the pretreatment is poor, the molten zinc cannot react with steel normally and completely to form the most perfect galvanized film structure. If the post-treatment is poor, the appearance of galvanized film will be damaged and the commodity value will be reduced.
Advantage
1. The whole steel surface is protected. No matter in the depression, the interior of the pipe fitting or any other corner where the coating is difficult to enter, the dissolved zinc can be easily and evenly covered.
2. The hardness value of zinc coating is greater than that of steel. The ETA layer at the top layer has only 70 DPN hardness, so it is easy to be concave due to collision. However, the zeta layer and delta layer at the bottom layer have 179 and 211 DPN hardness values respectively, which is higher than the 159 DPN hardness value of iron material, so their impact resistance and wear resistance are quite good.
3. In the corner area, the zinc layer is often thicker than other places, and has good toughness and wear resistance. Other coatings at this corner are often the thinnest, the most difficult to construct and the most vulnerable to injury, so they often need to be maintained.
4. Even due to great mechanical injury or other reasons. A small part of the zinc layer will fall off and expose the iron base. At this time, the surrounding zinc layer will play the function of sacrificial anode to protect the steel here from erosion. The other coatings are just the opposite. Rust will form immediately and quickly spread under the coating, causing the coating to peel off.
5. The consumption of zinc layer in the atmosphere is very slow, about 1 / 17 to 1 / 18 of the corrosion rate of steel, and it is predictable. Its life is much longer than any other coating.
6. The service life of the coating depends mainly on the thickness of the coating in a specific environment. The thickness of the coating is determined by the thickness of the steel, that is, the thicker the steel is, the thicker the coating is. Therefore, the thicker the steel part in the same steel structure must also get a thicker coating to ensure a longer service life.
7. Due to beauty, art, or when used in a specific severely corrosive environment, the galvanized layer can be treated with the above paint. As long as the paint system is selected correctly and easy to construct, its anti-corrosion effect is 1.5 ~ 2.5 times better than the combined service life of painting alone and hot-dip galvanizing.
8. In addition to hot-dip galvanizing, there are several other methods to protect iron and steel with zinc coating. Generally, hot-dip galvanizing is the most widely used method with the best anti-corrosion effect and the best economic benefit.
You can see the spabgle details in this photo, the spangle looks very tiny.
High coating mass hot dipped galvanized steel coil.