CGR Alloy Coatings
By using a small amount of Al (0.2%) in the zinc bath, the CGR coating process produces a coating that is almost pure zinc except for an approximately 0.1 micron ternary intermetallic alloy layer (Fe2Al5-xZnx) at the zinc/steel interface. Such a coating, because of its very thin alloy layer (the same as that produced on continuously galvanized sheet products), adheres very well and can be bent or stretched without cracking, and no peeling or flaking.
Further, the CGR process coats the steel with minimum exposure time to the molten zinc before cooling. Including the preheating stage, the total time the steel is at the temperature of the molten zinc (465 °C) is 4-5 seconds. This allows all grades of steel (normal and high strength) to be galvanized with no risk of embrittlement. In fact, any cold work stresses imparted to the bar by a straightening process prior to entry into the coating section are almost entirely relieved by the preheating prior to zinc bath entry. All grades of steel, including high strength steels, will have the same coating of essentially pure zinc. System produces coatings to ASTM A1094 standards.
CONVENTIONAL ZINC COATINGS
CGR Systems can automatically produce conventional hot dip galvanized coatings on reinforcing bars and profiles in accordance with the following standards:
EXCEPTIONAL PRODUCTION RATES
CONSISTENT AND PREDICABLE COATING THICKNESSES
Formability of CGR
The CGR process results in a flexible and adherent galvanized coating with no thick zinc-iron alloy layers. The coated bar can be bent, stretched, twisted or otherwise fabricated after the galvanizing process is complete without cracking or flaking the coating, regardless of the total coating mass. As a result, there is no zinc loss due to brittleness during forming in the field and repair requirements are minimal.
Fabricating CGR after galvanizing reduces transportation, manufacturing, and fabrication costs. The costs of installation and placement by accommodating last minute job site modifications and revisions are also reduced. This saves valuable time and money.