Galvanized coil

Product Standard

International standard
ISO Standards: The International Organization for Standardization (ISO) has developed a series of relevant standards, such as ISO 3244 and ISO 3254, which specify technical requirements for galvanized coils, including dimensions, weight, surface quality, and zinc coating thickness.
ASTM Standards: Standards such as ASTM A653/A653M, issued by the American Society for Testing and Materials (ASTM), are primarily intended for the U.S. market and manufacturing, specifying the performance requirements and technical criteria for galvanized steel coils.
Domestic standard
GB/T Standard: GB/T 2518-2019 is an important national standard for hot-dip galvanized steel sheets and strips, which specifies in detail their technical requirements, including dimensions, external shape, weight, surface quality, and zinc coating weight.
YB/T Standard: The industry standard YB/T 5148-2006 also specifies the dimensions,外形 (shape), weight, surface quality, and zinc coating weight of hot-dip galvanized steel strips and steel plates.

Intended Use

In the construction sector, it can be used to fabricate roofs, wall panels, canopies, ventilation ducts, bridges, and other structural components. Its superior corrosion resistance enables it to withstand wind, rain, and a wide range of harsh environmental conditions, ensuring that buildings maintain their aesthetic appeal and structural integrity over the long term.
Automotive manufacturing: Used in the production of car bodies, chassis, doors, and automotive components. The high strength, impact resistance, and corrosion‑resistance of galvanized coils help enhance vehicle safety and reliability, thereby extending the service life of automobiles.
Home appliance industry: It is a commonly used material for the housings of refrigerators, washing machines, air conditioners, and other appliances. Its excellent formability meets the demands of diverse and intricate exterior designs, while its corrosion resistance enhances the durability of home appliance products.
Communication equipment: In the communications industry, it is widely used in the manufacturing of base stations, towers, antennas, and other components, effectively preventing rust and corrosion in outdoor environments and ensuring the reliable operation of communication devices.
 

Product Introduction

Galvanized coil is a type of thin steel sheet whose surface is coated with a layer of zinc by immersing it in a molten zinc bath. Currently, the predominant production method is continuous galvanizing, in which coiled steel sheets are continuously passed through a zinc‑rich molten bath to produce galvanized steel. It possesses the following characteristics:
Excellent corrosion resistance: The zinc coating isolates the steel sheet from the external environment, effectively preventing oxidation and rusting, thereby significantly extending the service life of the steel.
Aesthetic appearance: It exhibits a silvery-white metallic luster and a relatively smooth surface, providing an excellent visual finish for a wide range of products.
Excellent processability: It can undergo various forming operations such as stamping, bending, and welding, meeting the shaping requirements of diverse products.

National Standard

GB/T 2518-2019 specifies the relevant technical requirements for galvanized steel coils; some of the key provisions are as follows:
Performance grade classification: Includes various grades such as general-purpose, mechanical interlocking, stamping, and deep drawing, to meet the requirements of different application scenarios.
Substrate types include cold-rolled coil and hot-rolled pickled coil, among others.

Classification of galvanized coatings:

Double-sided, equal-thickness galvanized coating: Specifies different coating weights and their corresponding designations, such as Z60, Z80, etc., which indicate the weight of zinc per square meter on both sides (in grams).
Differential thickness coating: The different coating weights on the upper and lower surfaces may be indicated as specified.
Zinc coating surface structure: It is classified into several types, including normal zinc spangle, fine zinc spangle, no‑spangle, and zinc‑iron alloy, each with its corresponding designation.
Surface quality classification: includes standard surface, higher‑grade surface, and premium surface, catering to the varying surface‑quality requirements of different users.
Surface treatment categories include passivation, oiling, paint sealing, phosphating, and no treatment. Different surface‑treatment methods impart distinct performance characteristics to galvanized coils; for example, passivation helps reduce rust under humid storage and transportation conditions, while oiling further enhances corrosion resistance.