0.12-4.0mm Full Width Z275 GI Steel Coil 30-1500mm

Product Specification

Precision-Gauge Hot-Dip Galvanized Steel Coil (0.12-4.0mm | 30-1500mm)
Advanced Zinc Protection for Industrial Durability

Galvanized steel coil is a high-performance corrosion-resistant material manufactured through continuous hot-dip galvanizing (GI) technology. This process bonds a metallurgically adherent zinc coating to cold-rolled or hot-rolled steel substrates, creating a superior barrier against environmental degradation. Available in thicknesses from ultra-thin 0.12mm to heavy-duty 4.0mm and widths spanning narrow-band 30mm to extra-wide 1500mm, our coils deliver exceptional versatility across manufacturing sectors. The characteristic spangled or smooth grey-white surface provides both functional protection and aesthetic readiness for painting. Engineered to meet ASTM A653, EN 10346, and JIS G3302 standards, this material combines sacrificial anode protection with mechanical strength – making it indispensable for structural applications in aggressive environments.

Technical Specifications & Parameters

Performance Advantages & Key Features

• Triple-Layer Corrosion Defense: 1) Zinc coating sacrificially corrodes first 2) Dense zinc carbonate patina formation 3) Iron-zinc alloy barrier - delivering 20-50 year service life in atmospheric exposure (ISO 9223)

• Superior Formability: Maintains ductility for 180° bending (ASTM E290) and deep drawing (Erichsen ≥9.0mm) without coating fracture

• Thermal Resistance: Withstands temperatures up to 200°C without significant zinc diffusion

• Eco-Sustainability: 100% recyclable with >30% recycled content; zinc coating reduces steel consumption via extended longevity

• Hybrid Protection: Combines barrier protection (physical shield) and cathodic protection (electrochemical reaction) mechanisms

• Weldability Excellence: Low surface resistance (≤100μΩ) enables seamless spot welding at 8-10kA current

Cross-Industry Applications
Construction & Infrastructure: Standing-seam roofing, structural framing (C/Z purlins), HVAC ducting, solar mounting systems, steel framing (LSF), bridge decking, noise barriers.
Automotive Engineering: Chassis components, truck trailers, fuel tank shields, underbody reinforcements, bus floor structures.
Appliance Manufacturing: Refrigerator liners, washing machine drums, oven cavities, AC compressor housings, water heater tanks.
Agricultural & Industrial: Grain silos, livestock equipment, conveyor systems, electrical enclosures (NEMA 4), cable trays, guardrails.
Consumer Goods: Metal furniture, storage racks, signage backplates, lighting fixtures, retail display systems.

Advanced Manufacturing Technology
Our continuous galvanizing line (CGL) employs the Sendzimir process with nitrogen-hydrogen atmosphere control:

1. Alkaline Electrocleaning removes oils (3-stage immersion, 70°C)

2. Acid Pickling (HCl, 15-20%) eliminates mill scale

3. Reductive Annealing at 720-850°C in H₂/N₂ atmosphere

4. Molten Zinc Bath immersion (Zn-0.2%Al at 450-460°C)

5. Air Knife Precision Coating controls thickness (±3g/m² accuracy)

6. Alloying Phase Development: Forms delta (FeZn₇) and zeta (FeZn₁₃) intermetallic layers (3-15μm) topped by eta-phase pure zinc

7. Tension Leveling enhances flatness (I-unit ≤8IU)

For galvannealed (GA) products, the strip undergoes in-line induction heating to 500-560°C, diffusing zinc into iron to create a matte grey Zn-Fe alloy coating (100% alloy layer) with enhanced paint adhesion and weldability. Our proprietary bath chemistry control ensures minimal dross formation while achieving coating adhesion class 1 (ISO 17872) – guaranteeing integrity during severe forming operations.