Galfan - A New Zinc-Alloy Coated Steel for Automotive Body Use

A new corrosion-resistant coating system, known as Galfan, has been developed for steel sheet and. wire. This alloy consists of eutectic zinc-5% aluminum plus a small addition of mischmetal (< 0.1%). It has demonstrated corrosion resistance more than twice that of conventional galvanized steel sheet or wire under similar conditions and similar coating thicknesses. The coating also has extremely good ductility under cold forming conditions and behaves comparably to conventional galvanized steel sheet with respect to spot weldability and paintability. The bath operating temperature is slightly lower than required for conventional continuous galvanizing baths, providing maximum economy in energy utilization and compatibility in coating high carbon steel spring wire. Conventional continuous galvanizing lines of the Sendzimir, Selas or Heurtey type can be converted to Galfan coating with a nominal capital investment, provided a cast iron or ceramic crucible is available. Recent research shows that Galfan may be adaptable to a Cook-Norteman continuous galvanizing line and to batch galvanizing. The development of this product fills a commercial need for a superior product with minimal changes in established conventional galvanizing processing methods.