What is galvanized steel coils
Overview
Steel is a commonly utilized material in industry and construction; however, it is susceptible to corrosion. Galvanization is a cost-effective approach to delay this process, which can be achieved through electro or hot-dip galvanization. At present, hot-dip galvanization is more popular in the market due to its benefits, including uniform coating, strong adhesion, and extended service life.
How to produce galvanized steel coils
Hot-dip galvanizing immerses the steel plate into molten zinc. Through the reaction and diffusion between iron and zinc, a zinc alloy with excellent adhesion is formed on the surface of the steel plate.
Anti-rust principle of galvanized steel
Hot dip galvanizing provides both physical and electrochemical protection to steel plates.
The rate of zinc layer consumption in the atmosphere is very slow, approximately 1/17 to 1/18 of the corrosion rate of steel. This results in a much longer lifespan compared to any other coatings.
Even if a small portion of the zinc layer falls off and exposes the steel, the surrounding zinc layer will act as a sacrificial anode to protect the steel from corrosion.
Application
Hot dip galvanized steel is widely used in various industries, including automobile, construction, household appliances, chemical industry, machinery, petroleum, metallurgy, light industry, transportation, electric power, aviation, and marine engineering. Common applications for galvanized steel include tiles, air ducts, containers, and mechanical equipment.
Customized galvanized steel coils
The usual form of delivery for hot-dip galvanized steel sheet is in coils with a weight range of 3-7 tons and a standard coil core diameter of 508mm. The length of each coil is dependent on its weight and thickness. Commonly used widths are 914mm, 1000mm, 1219mm, 1250mm, and 1500mm, which can be customized within the range of 600 to 1250mm, with a minimum order quantity of 25 tons. The thickness can also be customized within the range of 0.12mm to 3.0mm. The range of zinc coating can be customized from 20g to 450g per square meter. The hot-dip galvanized surface displays zinc spangles which can be customized into big spangles, small spangles, and non-spangle types.
Grades and standards
Dx51D+Z
This refers to the standard grade of galvanized steel as per the European standard EN 10142/10143. Dx52D+Z is the deep drawing grade, while Dx53D+Z is the ultra-deep drawing grade. If a number follows it, it is the structural grade, where the number indicates the yield strength, such as S340GD+Z. When it is Dx51D+AZ, it refers to galvalume, which is coated with a combination of zinc and aluminum.
The Chinese standards are similar to European standards in many ways. In the Chinese standards, Q is commonly used to represent the yield strength, such as Q235.
SGCC, SGCD, SPCC
SGCC is the galvanized grade under the Japanese Standard JIS G3302. SGCD refers to the deep drawing grade, while the structural grade is indicated by a number followed by the grade, such as SGC440. On the other hand, SPCC refers to color-coated galvanized steel.
CS A/B
CS is the American Standard ASTM A653m. FS refers to the deep drawing grade, while the structural grade is indicated by a number following the grade, such as SS275/Grade 40.