This alloy coating consists of 55% Aluminum and 43% Zinc and the balance contains Silicon around 1.5% to affect excellent adhesion to the steel substrate.
Galume Production Technology:
This coating is given on the cold rolled substrate processed from selective Hot rolled coils with selective chemistry for getting the desired mechanical properties specified by the customers. The Galume product is made by the continuous hot dip process. The cold rolled coils are welded end to end and passes through 3 stage degreasing section for achieving excellent cold rolled strip surface. The coating system is 2 pot system- premelting pot and the main coating pot. The bath chemistry is continuously controlled and monitored at the pre melting pot which continuously feeds the main coating pot thro the refractory tunnel.
In India, Galume and Pre-painted Galume are used by reputed companies like Kirby, Tigger steels, Lloyds Insulation, Multicolor, GSP Power, ERA Metal Bldg, Unimet Profiles, Isolloyds Eng, Color Roofing, Hawells India Ltd, MG Industries, Ganga roofers, Metco Roof-Pondy, Century wells and others. There are no Indian standards for this product. Available sheets are as per international market norms like ASTM / EURO and AS standards. Some of our Global users are Defer co-USA, NOVO Steel USA, Toyota Tshuho, America Nialco SA Belgium, Savogni Italy, Gibbs Steel, South Africa, Arcelor BarbaDOS, Global Roofing-Durban and others.
Technical Data Sheet For Galume Products
|Parameters||Technical details / Specifications / Stds|
|Reference Standard||ASTM 792/A 792M|
|Other ref:Standard||En 10326/En 10327, AS 1397, JIS G 3321|
|Chemical composition (base metal)||Low carbon steel %C:0.12 max, %Min:1.2Max %S:0.03 max, %P:0.03 Max|
|Strip thickness mm||0.20 to 1.5 (<0.20 & above 1.5 in special cases)|
|Strip widths mm||900 to 1250|
|Chemical Composition (Coating)||55% Al-Zn alloy with 1.6% Si|
|Test method for coating mass gms/m2 determination for the single spot and triple spot test.||ASTM A 90/A 90M|
|Grade designation||Gr 50 / Gr 80/CS types (A,B)|
|Yield Strength Mpa Tensil Strength Mpa||340 min for Gr 50 & 550 min for Gr 80
410 min for Gr 50 & 570 min for Gr 80
|Coating mass gms/m2 Coating class||70 to 165 AZM 150/165 as per ASTM std|
|Surface condition/treatment||Spangle skin passed – surface chrome passivated & oiled/Resin coated surface tratment chemicals from M/S Henkel Chembond|
|Testing of Mech Properties||ASTM A924/A 924M|
|Microstructure design||Galume structure consists of two layers of Al-Zn overlay coat and Fe containing intermetallic/alloy layer. Al gives barrier protection and Zn gives sacrificial Galvanic protection to the steel substrate.|
|Resistance to corrosion -Salt spray life Min Hrs (ASTM B 117)||1000 HRS, corrosion 5 % (max) for Acrylic coated.|
|Heat resistance and heat reflectivity properties.||Due to bright surface & fine spangles, excellent heat reflectivity up to 315 c, & due to high Aluminium content, Galume has heat (oxidizing) resistance up to > 320 c without discoloration and without impairment of its alloy coating.|