Zinc-Aluminum-Magnesium Coil

Product Standard  

The product standards for zinc‑aluminum‑magnesium coils are primarily based on the following two national standards:
GB/T 3277-2015 “Steel Wire Ropes with Aluminum–Magnesium Alloy Coating for Galvanized Steel Wire Ropes”: This standard specifies the technical requirements, test methods, inspection rules, as well as marking, packaging, and transportation for steel wire ropes coated with an aluminum–magnesium alloy. However, it primarily addresses aluminum–magnesium alloy coatings applied to galvanized steel wire ropes and is not entirely identical to the zinc–aluminum–magnesium coil coating; nonetheless, certain testing methods and the rationale behind some of the specified performance criteria offer useful reference.
QB/T 4953-2017 “Zinc–Aluminum–Magnesium Alloy‑Coated Steel Sheets and Strips”: This is an important standard for zinc–aluminum–magnesium alloy‑coated steel sheets and strips, specifying their technical requirements, test methods, inspection rules, as well as marking, packaging, and transportation. It also sets forth technical specifications for the zinc–aluminum–magnesium alloy, including the contents of zinc, aluminum, and magnesium; the zinc-to-aluminum ratio; coating thickness; adhesion; corrosion resistance; and other relevant parameters.
In addition, for the application of zinc–aluminum–magnesium products in the highway guardrail sector, there is also the group standard T/CECS 10434-2024, “Steel Strip with Continuous Hot‑Dip Zinc–Aluminum–Magnesium Alloy Coating for Highway Guardrails,” which came into effect on May 1, 2025, providing technical support and a normative basis for the use of zinc–aluminum–magnesium alloy‑coated steel sheets in industries such as highways and bridges.

Intended Use

In the construction sector, it is widely used for roofing, wall cladding, steel structures, and other applications. For instance, in both residential buildings and industrial facilities, it serves as roof panels and exterior wall panels, providing long-lasting protection. In coastal areas or regions with significant industrial pollution, its excellent corrosion resistance effectively safeguards against aggressive agents such as chloride ions and sulfur dioxide. It is also suitable for structural components in buildings, including suspended ceiling grids, perforated panels, and cable trays.
Agricultural sector: Steel structures and steel components suitable for constructing agricultural livestock greenhouses and glass‑house facilities, capable of meeting the livestock industry’s specific requirements for materials in humid and chemically corrosive environments.
Automotive industry: It can be used for automotive body panels, helping to enhance the overall strength and stiffness of vehicles. Some high-end automotive sheet‑metal manufacturers have already begun producing zinc‑aluminum‑magnesium automotive sheets.
In the field of power‑communication, this material is used in equipment such as power transformers and capacitors, as well as in outdoor power‑communication infrastructure—including high‑ and low‑voltage switchgear and the enclosures of packaged substations—owing to its excellent corrosion resistance and mechanical strength, thereby ensuring stable operation under outdoor conditions.
Railway transportation sector: Used for exterior panels, doors, and other components, it can enhance the performance and service life of railway vehicles.
Photovoltaic Industry: Widely used in the photovoltaic sector—for components such as mounting brackets and solar panel frames—this material exhibits excellent weather resistance and corrosion resistance, making it well-suited to harsh environments like coastal regions and deserts. It helps mitigate the risk of bracket failure due to corrosion, thereby ensuring the stable operation and long-term performance of photovoltaic systems.

Product Introduction  

Zinc‑aluminum‑magnesium coil is a new, environmentally friendly metallic material, typically composed of an alloy coating containing zinc, aluminum, and magnesium, which is applied to steel sheets or strips via hot‑dip galvanizing and other processes. It possesses the following characteristics:
High corrosion resistance: The addition of magnesium to the coating promotes the formation of a dense oxide film, resulting in corrosion resistance 5 to 10 times greater than that of conventional hot-dip galvanized steel and meeting stainless steel standards. It delivers outstanding performance in salt-spray tests, with a service life exceeding 30 years, making it ideal for environments characterized by high salt spray, high humidity, and industrial pollution.
Cut‑edge self‑healing capability: Upon cutting or scratching, alloying elements in the coating dissolve to form protective films such as zinc hydroxide and magnesium hydroxide, which coat the cut edge and inhibit the formation of red rust, thereby significantly extending the material’s service life in harsh environments.
Excellent processability: It exhibits superior bending, stamping, and welding performance, meeting the forming requirements of complex components. The coating is denser than that of conventional galvanized sheet, resists delamination during stamping, and offers strong adhesion for surface coatings, allowing direct application of paint or film finishes.
Environmental and Economic Benefits: The coating contains no harmful substances such as chromium, complying with environmental standards like the RoHS Directive. Moreover, the coating is relatively thin—typically 40 to 275 g/m²—which helps reduce resource consumption and extend service life, thereby lowering life-cycle costs.
 

National Standard

The two national standards mentioned earlier specify the relevant performance criteria for zinc‑aluminum‑magnesium coated coils.
QB/T 4953-2017 specifies the technical requirements for zinc–aluminum–magnesium alloy‑coated steel sheets and strips. With respect to chemical composition, it defines the permissible ranges for zinc, aluminum, and magnesium contents, as well as the zinc-to-aluminum ratio. Coating thickness is governed by specific requirements tailored to different application needs. In terms of performance, stringent test methods and acceptance criteria are established for adhesion, corrosion resistance, and other properties. For instance, corrosion resistance is assessed using methods such as the neutral salt spray test, with a requirement that no red rust shall appear after a specified number of hours.
GB/T 3277-2015: Although primarily intended for galvanized steel wire ropes with aluminum–magnesium alloy coatings, it also provides useful reference for certain aspects of zinc–aluminum–magnesium coils, such as the testing methods and basic alloy composition requirements. For instance, it specifies permissible ranges for the contents of aluminum, magnesium, and other elements in the alloy to ensure the coating’s performance.