Preventing Corrosion of Auto-Body Steel Adjacent to Stainless Steel Trim 680144
A stainless steel trim system to prevent galvanic corrosion of adjacent auto-body steel is described. A composite strip consisting of stainless steel with aluminum on one side would be processed conventionally to molding. The aluminum would be on the concave (back) side of the formed molding, and stainless steel on the convex side, including the visible surfaces and return or faying surfaces of the molding. After forming, the return surfaces of the molding would be roll-or wipe-coated with a paint or wax to provide electrical insulation at the faying surfaces of trim and auto-body steel. Laboratory studies leading to this development are described. Road-exposure tests conducted on a corrosion-test trailer showed that the stainless steel-aluminum composite performed better than uncoated stainless steel, and that coating the faying surfaces of stainless trim with either paint or wax was beneficial. When the stainless steel-aluminum composite trim was coated on the faying surfaces galvanic corrosion of the automobile body was entirely prevented.