BODY PANEL CONSTRUCTION CN-2 RUST-RESISTANT SHEET STEEL PARTS Rust-Resistant Sheet Steel have zinc, tin or aluminum etc, plating over the base metal surface in order to improve the corrosion resistance of the sheet metal. This sheeting is used on areas that require anticorro- sive abilities but there is no need to distinguish the differences between rust resistant sheet steel and ordi- nary sheet steel in body repair. Body panels on TOYOTA models are made of two different melted galvannealed sheet steel. The ordinary melted galvannealed sheet has a zinc plating over the base metal surface and when heated a zinc-iron alloy plating.
The zinc-iron double layered galvannealed sheet has a iron rich and another zinc-rich layer above the sheet steel. These 2 layers improve paint adhesion. These two melted galvannealed sheet steels are used selectively according to need. Fe-Zn Alloy (Iron Rich) improves paint quality Zn-Fe Alloy (Zinc-Rich) Zn-Fe Alloy (Zinc Rich) improves rust-resistant performance Base Metal Base Metal Galvannealed Sheet Steel Double Layered Zinc-Iron Galvannealed Sheet Steel The handling of Rust-Resistant Sheet Steel is the same as for ordinary sheet steel, but the following should be observed. 1. Panel Welding:
The paint as well as the zinc portion must be removed completely from the welding area to guarantee good welding integrity. 2. Anti-Rust Treatment: Since the zinc plating is lost after welding, anti-rust treatment of the welded area must be thoroughly performed (refer to section AR).