Hot dip galvanized steel coil is a type of steel that has been coated with a layer of zinc through a hot dip galvanization process. This process involves immersing steel in molten zinc, which creates a durable and corrosion-resistant coating that protects the underlying steel from rust and degradation.

Key Features and Benefits:

1. Corrosion Resistance: The zinc coating acts as a barrier to moisture and oxygen, which are necessary for corrosion to occur. This makes hot dip galvanized steel highly resistant to rust and extends the lifespan of the steel.

2. Durability: The coating is bonded metallurgically to the steel, making it more durable than other types of coatings, such as paint. It can withstand harsh environmental conditions.

3. Maintenance-Free: Once galvanized, the steel requires little to no maintenance, which can result in lower lifecycle costs.

4. Versatile Applications: Hot dip galvanized steel coils are used in a variety of applications, including construction (for roofing, siding, and structural components), automotive parts, and manufacturing of appliances and furniture.

5. Aesthetic Appeal: The galvanized finish has a unique appearance that can be desirable in certain applications, and it can be painted or left in its natural state.

Manufacturing Process:

1. Surface Preparation: The steel coil is cleaned to remove any mill scale, rust, or contaminants. This typically involves pickling in an acid solution.

2. Fluxing: A flux solution is applied to the clean steel to prevent oxidation before galvanizing.

3. Hot Dip Galvanizing: The prepared steel is immersed in a bath of molten zinc at around 450°C (842°F). The zinc reacts with the iron in the steel to form a series of zinc-iron alloy layers.

4. Cooling: After galvanization, the coated steel is cooled, usually by air or water, to solidify the zinc coating.

5. Finishing: The final product may undergo additional processes such as cutting, slitting, or further finishing to meet specific customer requirements.

Standards and Specifications:

Hot-dip galvanized steel coils are produced according to various industry standards that ensure their quality and performance. The most common standards include:

1. ASTM A123/A123M: This standard outlines the specifications for zinc (hot-dip galvanized) coatings on iron and steel products. It covers various forms of steel, including coils, sheets, and structural shapes.

2. ASTM A653/A653M: This standard specifies the requirements for hot-dip galvanized steel sheet, which can also apply to coils. It includes requirements for the coating weight, mechanical properties, and surface quality.

3. ISO 1461: This international standard specifies the requirements for hot-dip galvanized coatings on fabricated iron and steel articles.

4. EN ISO 1461: This European standard is similar to ISO 1461 and provides guidelines for the specifications of hot-dip galvanized coatings.

5. JIS G3302: This is a Japanese industrial standard that covers hot-dip galvanized steel sheets and coils, including specifications for coating weight and mechanical properties.

6. GB/T 13912: This is a Chinese standard for hot-dip galvanized steel products, specifying requirements for the zinc coating and mechanical properties.

When selecting hot-dip galvanized steel coils, it’s essential to know the intended application and the specific requirements, such as coating thickness, mechanical properties, and corrosion resistance, to choose the appropriate standard.

Sino Unicorn International Co., Limited supplies up to standard Hot Dip Galvanized Steel Coils/Sheets as per customers’ requirements. Here is the common size range we can offer: 0.12~4mm x 750~1850mm x C with Zinc coating from 20g/sqm ~ 400g/sqm. And regular grades are DX51D ~ DX54D, S250GD ~ S550GD. For more details please feel free to send your requirement to email: info@sino-unicorn.com. We will respond as soon as possible.