WELDING METHOD OF COPPER AND COPPER ALLOY HAVING HIGH STRENGTH AND HIGH CONDUCTIVITY

PURPOSE:To reduce a strength drop of a welded joint part, and also to obtain a joint performance of a high quality, by preheating a weld groove part of copper and a copper alloy having high strength and high conductivity, also cooling a member located in the vicinity of a weld, and executing TIG (tungsten inert gas) welding. CONSTITUTION:Materials to be welded 1, 1 consisting of thick plate hard copper to which working and hardening treatment is performed are butted in the L- shaped or J-shaped groove, a high frequency heating coil 5 is placed, and TIG (tungsten inert gas) welding is executed, holding a temperature of a wall side groove face at a temperature of >=about 300 deg.C by a high frequency induction heating device. Also, water-cooling jackets 6, 6 provided with water leakage preventing rubber packing 7 are provided on the materials to be welded 1, 1, and the members to be welded 1, 1 are cooled forcibly. In this way, a weld 2 having a good X-ray quality is obtained, and also a strength drop can be prevented by reducing a softened area. Also, an excess metal 9 is formed on the weld 2, it is welded, and thereafter, is hit with a hammer, etc., by which strength of the joint can be raised remarkably.