| 摘要 |
PROBLEM TO BE SOLVED: To provide a method and a device for resistance welding which can prevent a deterioration in toughness of a joining part, cracks at the joining part, and aging cracks even if carbon steel (a metal member) having a carbon content higher than medium carbon steel is joined by the resistance welding. SOLUTION: A pressure-welding part is joined by making a current to flow into a common rail body 20, which is formed of the carbon steel having a carbon content rate of 0.35 wt.%, and a holder 26. Continuously, annealing treatment for gradually cooling the temperature at the high-temperature joining part 30 is applied by controlling a current value, which is made to flow into the common rail body 20 and the holder 26, and an energization time. Then, the Vickers hardness at the joining part 30 can be set to≤600 HV. A large part of the metal composition at the joining part 30 can be set to the intermediate stage phase. As a result, the toughness at the joining part 30 is improved. Accordingly, it is possible to prevent occurrence of the cracks at the joining part 30 and the aging cracks. COPYRIGHT: (C)2005,JPO&NCIPI |
