شیت فولادی گالوالوم غوطه‌ور در حرارت (GL)

Introduction

Hot dipped Galvalume steel coil carries a 55% aluminium, 43.4% zinc and 1.6% silicon coating, applied on a continuous line over cold rolled substrate. BOMIS supplies it from AZ30 to AZ200 g/m², 600 to 1250 mm wide, with the mill certificate on every coil.

ویژگی‌ها

The coating protects in two ways at once. Aluminium builds a dense oxide layer that slows attack, and the zinc fraction sacrifices itself at cut edges and scratches where the coating has opened. That pairing is why Galvalume holds up roughly two to five times longer than hot dip galvanized steel in the same exposure, and why it keeps reflecting heat as the surface dulls.

Heat is the other reason buyers specify this grade. The coating stays intact at temperatures that soften pure zinc, so exhaust parts, oven internals and industrial drying equipment come up often. Forming is straightforward on press brakes and roll formers, and the grade is quoted to ASTM A792 or JIS G3321, depending on which standard your drawing calls up.

مشخصات

کاربردها

Galvalume earns its cost in humid and salt-laden air, which is where galvanized steel gives up first. Coastal sites, monsoon climates and chemical corridors are the three specifications we quote most, and each one shifts the coating weight rather than the grade.

• Roofing and wall cladding on ports, docks and offshore platforms
• Factory buildings, warehouses and housing in tropical or monsoon climates
• Ventilation ducts and equipment casings around chemical plants
• Flue gas treatment components and other SO₂ and Cl⁻ exposures
• Solar mounting structures and agricultural buildings

پردازش

Coils run on our own galvanising line, so the coating weight is set to your corrosion target rather than to whatever suits the schedule. We slit to press width or cut to sheet size in house, and both options arrive on the same certificate as the parent coil.

Lead time runs about three weeks for standard specifications. Coil inner diameter is 508 mm or 610 mm, and coil weight is confirmed with the order.

بسته‌بندی

Coils ship with the mill certificate and edge protectors on both ends. Standard sea packing is waterproof kraft paper under a galvanised steel jacket, steel strapped, which holds through a forty day crossing without edge rust. Eye to the sky or eye to the wall, your call.

پرسش‌های متداول

How is Galvalume different from galvanized steel?

Galvanized is pure zinc and protects by sacrificing itself. Galvalume is an aluminium-zinc alloy, so the aluminium blocks attack and the zinc covers cut edges. It costs more and lasts far longer in humid or coastal air.

Can Galvalume be painted?

Yes, with a suitable pretreatment. The surface is harder to paint than galvanized, so it is usually specified as prepainted coil rather than painted after forming.

Do you supply MTC with each coil?

Yes. Every coil leaves with its mill test certificate, and we confirm which document you need before production starts.

What is the MOQ and lead time?

16 metric tons per specification, and about three weeks for standard specifications.

Which coating weight should I specify?

AZ150 covers most outdoor roofing, and AZ200 is for coastal or industrial exposure. Indoors, AZ30 to AZ100 is usually enough and costs less.

Do you ship cut-to-length sheet as well as coil?

Yes. Sheet is cut in house to your length and bundled separately, so it travels in the same container.