Specially coated tubes are requested by GM for the hydraulic steel tubes carrying fluids for automotive such as brake lines, transmission cooler lines etc., with a GM designation GE.
It is named Zinc-Aluminum Alloy-Extended Corrosion Protection by GM, and called ALGAL coating mostly in China.
It is defined as the following:
Zinc-aluminum alloy as described in GALFAN , with coating thickness 3 micrometer, i.e. 50 g/m2 per ASTM A875, followed by an approved pre-treatment process and an approved aluminum-rich epoxy coating.
The purpose of this process is still enhance the corrosion resistance of the tubes further to 1000 hr min.
We use hot dip galvanizing to replace GALFAN yet maintaining the equivalent corrosion protections.
