| 摘要 |
PURPOSE:To prevent the formation of coarse grains of crystals and the generation of brittle defects or the like in accordance with partial overheating by cooling the inner side of the curved part of a bent pipe by spraying gas-liquid mixed fluids thereby heating all parts of the bent part roughly uniformly. CONSTITUTION:In the stage of conducting electrically between electrodes 4 and 4 mounted to linear parts 2, 2 from an electric power source part 5 and bending a pipe 1 under heating, gas-liquid mixed fluids 8 consisting of air and water are sprayed like mists to the inner side 6 of a curved part 3. The fluids are sprayed to the pattern of a circular or elliptical shape along the longitudinal direction of the pipe 1. The inner side 6 of the part 3 having a short electric conduction distance and a tendency toward increasing of wall thickness and overheating is cooled by the spraying of the fluids 8, whereby the temp. differences between said side and the outer side 9 are virtually eliminated and the partial overheating is prevented. |
