Resistance welding method for steel - and aluminum - metal plates and resistance welding material

摘要

The present invention relates to a resistance welding method suitable for spot welding of a steel metal plate to which rust preventive treatment is applied through plating process and an aluminum metal plate, and is intended to realize high-quality welding by allowing high-density current to flow between a plated steel plate and an aluminum clad steel plate. An aluminum clad steel plate constituted by a steel layer having raised portions and an aluminum layer is interposed between a plated steel plate and an aluminum metal plate which are to be welded together. A predetermined welding current is supplied to an electrode from an alternating-current power supply. Since the supply path of the welding current is limited by the area of the raised portions, and since molten plating material produced when the plated layer is melted is received in pitch portions between the raised portions, the expansion of the current supply area is prevented. As a result of this, the interface between the plated steel plate and the aluminum clad steel plate is efficiently heated, whereby suitable nuggets are formed on both sides of the aluminum clad steel plate. IMAGE