Electric currents are generally used in either of two ways to joint cold-formed steel
components, with electric-arc welding or resistance welding. The former method is described in Art. 8.16 and the latter in Art. 8.17.
Welding offers important advantages to fabricators and erectors in joining steel structural components. Welded joints make possible continuous structures, with economy and speed in fabrication; 100% joint efficiencies are possible.
Conversion to welding of joints initially designed for mechanical fasteners is poor practice. Joints should be specifically designed for welding, to take full advantage of possible savings. Important considerations include the following: The overall assembly should be weldable; welds should be located where notch effects are minimal; the final appearance should not suffer from unsightly welds; and welding should not be expected to correct poor fit-up.
Steels bearing protective coatings require special consideration. Surfaces precoated with paint or plastic are damaged by welding. Coatings may adversely affect weld quality. Metal-coated steels, such as galvanized (zinc-coated), aluminized, and terne-coated (lead-tin alloy), however may be successfully welded using procedures tailored for the steel and its coating.
Generally, steel to be welded should be clean and free of contaminants such as oil, grease, paints, and scale. Paint should be applied only after the welding process.
