Abstract: A method and apparatus for resistance welding in which, while both or one of the electrode center axes of a pair of opposing electrodes is inclined with respect to the electrode forcing axis, the electrode tip of the electrode is intermittently pivoted about the electrode center axis for welding. The contact between the electrode tip and workpiece is moved at a preset number of welds to define a next contact surface on the face of the electrode tip, and thus the number of welds (electrode tip life) is considerably improved.

Abstract: Method and apparatus for high-power-density beam welding in combination with upset welding. The method comprises forming, along abutting edges of metal materials to be welded, a continuous upset weld line, and subsequently beam welding the metal materials by irradiation by a high-power-density beam along the weld line. The output of the high-power-density beam is determined on the basis of an input heat produced by resistance heating in the metal materials during the upset welding, as well as a welding pressure given to the metal materials during the upset welding.

Abstract: A method of igniting arcs wherein an electric field is formed in the vicinity of an electrode and ignition-plasma is projected against a cathode in the electric field, to thereby ignite an arc.

Abstract: A container having an EOE with a tab affixed by welding is provided. In the EOE the top wall is made of surface treated steel sheet and the tab is made of stainless steel sheet or tin free steel sheet and the ultrasonic welding is used to fix the tab to the top wall. Through the invention monometallized containers can be supplied easily and cheaply.

Abstract: Disclosed herein is an improvement of a welding process for welding a steel pipe, wherein a gas metal arc welding is performed to form the first welding layer and a submerged arc welding is performed to form the last welding layer. According to the conventional gas metal arc welding process, i.e. the MIG or CO.sub.2 welding processes, the combined use of a high welding current and a welding wire having a small diameter is known to bring about the rotation of the welding arc and the formation of an undercut along the toe of the weld metal. The purpose of the present invention is to weld a steel pipe having either a large thickness or an excellent ductility at a temperature of less than -40.degree. C., or both. According to the present invention, the combined use of a high welding current and a wire having a small diameter is possible, by employing a gas mixture containing an inert gas as a major part thereof and CO.sub.2 as an additional part thereof as a shielding gas.