High-frequency electric resistance welding method using irradiation with a laser beam

A high-frequency electric resistance welding method combined with the irradiation of a laser beam, comprising the steps of:

• continuously feeding a workpiece and forming opposed edges thereof into a wedge shape by causing them to converge as they are butted against each other;
• heating the butted opposed edges with a high-frequency electric current;
• and
• presetting a position for a laser beam to be projected against the vertex of the butted edges of the wedge shape at the level being in a range of from above 30% and below 80% of the thickness of the butted edges at the workpiece including a central position of the thickness;
• projecting a laser beam against the vertex of the butted edges of the wedge shape from its open side at said predetermined level of said thickness, to thereby heat the vertex of the butted edges of the wedge shape to a welding temperature;
• whereby the butted edges of the workpiece are uniformly heated through the entire range of said thickness.