Abstract
Resistance spot weldability of coated steels for automobile applications was investigated. Test samples were prepared from commercial products of 0.8 mm in thickness. Based on the tensile-shear test, surface quality examination and cracking behavior, it was clear that aluminized steels showed good weldability. Microstructural inspection revealed that the coated materials was piled up at the split zone in the welding of aluminized steels. It was also demonstrated that no weld crack was found in the aluminized steel weld metal even the welding was carried out with higher current. However, through thickness cracks were detected at the weld metal of zinc coated steel. Small particles were found on the crack surface of zinc coated steel weld metal. It was thought that zinc vapor played key role to form the weld crack.