We Provide

BHUSHAN has set up the technology of manufacturing a very new coated product called BHUSHAN RAINBOW PLUS PREPAINTED GALUME being the brand name. This alloy coating consists of 55% Aluminum and 43.5% 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 through the refractory tunnel.

Technological backups:
The coater technology is the latest from GFG, USA and thermo Radiometric ? Germany and special high jet cooling tower from UK. We have tie up with M/s Henkel Chembond Surface Technologies Ltd for the supply of chromating chemicals and acrylic coating and 0n line continuous monitoring for the coating control and salt spray analysis in addition to our on line monitoring by quality control deptt.

Quality control:
We have full fledged laboratory with test equipments- Emission spectroscope for the chemical analysis, computerized Universal testing machine with stress-strain graph for tension tests, surface finish tester, Hardness testers using both Vickers and Rockwell scales, LFQ testing machine, Cupping tester, on line Radiometric and off line chemical lab for coating mass, salt spray tester for corrosion resistance, and Humidity chamber.

Galume market:
We have produced about 3,00,000 MT as on date from the commissioning of our Galume production. Our line is fully booked and hopes to produce continuously about 1,30,000 MT per month.
In India, we are supplying Galume and Pre-painted Galume to reputed companies. To mention few of them, we supply to Kirby, Tigger steels, Lloyds Insulation, Multicolor, GSP Power, ERA Metal Bldg, Unimet Profiles, Isolloyds Eng, Color Roofing CRIL, Hawells India Ltd, MG Industries, Ganga roofers, Metco Roof-Pondy, Century wells and others. Our 80 % of production is exported to various counties all over the world, USA, European Countries and Spain, South Africa, Italy and South East Asian countries. There are no Indian standards for this product. We have established our product in international market against ASTM / EURO and AS standards. It is imperative to mention to you that now our product or brand is preferred over Arcelor and Blue scope. Some of our Global direct customers 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.

Advantages :

The most significant difference is the substrate coating Mass composition:

Galvanizing uses almost pure zinc for coating and Galume uses 55% Al-Zn alloy, 1.6% Si, balance Zn. Due to this, Galume is processed at higher bath temp (as compared to galvanizing), due to higher melting point of Al-Zn-Si alloy.

2)    Coating thickness advantage in Galume material Density of Galume is 3.75 gms/cm3, and the density of  galvanized metal is 7.14 gms/cm3. Due to this density

difference, Galume coating mass gives higher coating in microns as compared to the same coating mass  in Galvanized product.  For e.g: 150 gms of Galume gives 40 micron coating   thickness and Galvanized material for 150 GSM gives   21 micron coating thickness. In other words, Galume  coating gives 52.5% more coating thickness than galvanized coating for the same GSM.


3) GALUME MICROSTRUCTURE:Galume coating has unique micro-structure consisting of 2 layers i.e.an Al-Zn overlay coating and a Fe containing

   intermetallic /alloy layer. Alloy layer forms at theinterface between the coating and steel substrate. Due to this, Galume combines the Galvanic corrosion protection of Zn with the barrier protection of Aluminum   as compared to only  Galvanic protection in galvanized metal.



In case of Corrosive environmental conditions, the Zn rich interdendritic portion of the coating corrodes preferentially. As this occurs, Zn  being sacrificial to steel, serves to galvanically protect the steel substrate. As the Zn portion of the coating is gradually corroded, the interdendritic interstices are filled with Zn corrosion products. The coating is transformed into a composite  comprised of an Aluminium rich matrix locking Zn corrosion products to offer a physical barrier and act as corrosion inhibitors.




   Presence of Al phase, bright surface and fine spangles-enhances superior heat reflectivity. This results into ideal cool roof for hot climates–resulting into cooler buildings/reduced air conditioning costs. Galume has excellent heat reflectivity, up to operating temperatures  of about 315°C (600°F). This heat reflectivity makes a  building cooler inside on hot, sunny days.





   Galume steel resists intermediate and high temperatures far more effectively than galvanized steel. Specifically, Galume steel shows no discoloration up to 315°C (600°F) during continuous or intermittent exposure over a  prolonged period. Above this temperature, some discoloration does occur and roughening of the surface is possible. Neither this discoloration nor roughening

   reduces Galume resistance to rust. Galume maintains its rust-resistance up to 675°C (1250°F).




Galume is twice as hard as Zinc coating. Measurement in Vickers hardness in the coating:- Galume Coating hardness is 140 Hv 0.5 Kg Zinc Coating hardness is 70 Hv 0.5 Kg

8) EXCELLENT IMPROVED FORMABILITY Galume in acrylic coated condition results in built –

   in roll forming lubricant. This has ability to suppress  galling on the metallic coating during cold profiling/forming thus giving improved roll forming without the use of supplemental lubricants. This results in less roll form  build up, less damage to coating and minimum pick up on rolls. This improves resistance to hand & finger marking,improves resistance to differential darkening & finally higher quality appearance.




Salt spray  laboratory results as per ASTM-B-117  gives more than 1000 HRS (in acrylic coated) for white rust corrosion resistance as compared to 72 HRS corrosionresistance in chromated Galvanized material.While zinc coated steel becomes dark grey during ageing, Galume ages very well and virtually remains same because of its main ingredient Aluminium which forms fine surface layer of invisible oxide and maintains a pleasing appearance with distinctive white metallic sparkle






                        ANUJ STEEL CENTRE


                        OFF : 1430/A, ‘C’, SAMBHAJI PUL, LAXMIPURI,KOLHAPUR-416002 

PH. 0231-2641610 , FAX – 0231-2641423

                        DEPO:  120/1  PUNE BANGLORE HIGHWAY,


               Email : anujsteel@ yahoo. co.in     Web :www.anujsteelroofing.com

Bhushan Rainbow Plus

Technical details/specifications/Stds
Product name
Reference standard
ASTM 755, ASTM A 792/A 792M
Other containing standards
JIS 3322, ECCA
Strip thickness mm
0.20 to 1.2 (< 0.20 & above 1.2 in special cases)
Strip width mm
900 to 1250
Substrate material
Galume coating as per ASTM A 792/A 792M with steel base as per ASTM std
Substrate Coating mass gms/m2 Substrate coating mass class
70 to 165 AZM 150/165 as per ASTM std
Grade designation
Gr 50/ Gr 80/CS type A, B as per ASTM std
Yield strength Mpa Tensile strength Mpa
340 min for Gr 50 & 550 min for Gr 80
410 min for Gr 50 & 570 min for Gr 80
Paint type
Paint coating thickness (DFT)
Top coat 18 to 22 microns (+5 microns primer)
Back coat 5 to 8 microns ( including primer)
Digital DFT meter accuracy
Accuracy +/- 2% of reading) as per ASTM A 153
Pencil hardness
H or Harder
15-80% at 60 degrees ASTM D 523
Resistance to chalking QUV
2000 HRS ?rating =4 for PVDF,
1000 HRS ?rating =4 for others
Resistance to corrosion
(ASTM B 117)
1000 HRS with blister density =2, creepage =2 mm
Resistance to Humidity
1000 HRS blister density = 2 (ASTM D 2247)
Resistance to color change QUV- ASTM G 53
2000 HRS (delta E = 5 unit) for PVDF
1000 HRS (delta E = 5 unit) for others
4 T- (ECCA) - no cracking
Resistance to abrasion
=20 mg as per 100 cycles
Resistance to Acid/solvents
No discoloration/no blistering- ASTM D 1308
Product certification
All products are accompanied with MTC and packing list.
Quality System
ISO 9001 - 2000

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