Forming GA-coated steel
Typical forming methods like bending, stretching, and drawing are suitable for galvannealed coated steels when using the proper forming parameters. Galvannealed coatings have a higher hardness than traditional zinc (GI) coatings, providing increased scratch protection during forming. GA coatings can lead to powdering during drawing, which can be minimized or eliminated by the proper forming set-up and by specifying thin galvannealed coatings. Galvannealed coatings have good laser-cutting properties, which can reduce your laser cutting costs.
Welding galvannealed coated steel
In general, galvannealed coated steels are considered optimal for the resistance welding of corrosion-resistance steels. Compared to traditional zinc (GI) coatings, galvannealed coatings allow a much larger range in welding currents. With lower welding currents, GA coatings enable longer electrode service life. And with the correct welding parameters, galvannealed welded joints are comparable to those on uncoated steel.
Painting galvannealed coated steel
Conventionally applied paint readily adheres to galvanneal’s finely structured matte surface. As with all painting, any oils or impurities must be fully removed prior to painting. To further improve coating adhesion, you can use pretreatments in the receiving plant that are suitable for zinc-based coated steels, such as zinc-phosphating. When requested, improved surface quality B is obtained by skin passing.