| 摘要 |
PURPOSE:To obtain a welded joint of steel having superior hydrogen erosion resistance as welded by providing a burner group moving together with a welding torch and adjusting the spacings between the burners in accordance with the temp. difference between the two points of weld heat affectd zones. CONSTITUTION:A gas burner support 8 is fixed in the direction at a right angle to the axial direction of a welding torch 7, and plural pieces of gas burners 9 are provided freely movably. The spacings between the burners 9 are set gradually smaller the nearer the torch 7 side. When the support 8 moves in the welding advance direction in accordance with the advancing of the torch 7, temp. sensors 12A, 12B detect the temp. of the weld heat affected zones. Based on the detection signals thereof, the number of pieces of the burners 9 on the surface of the gas burner support and the spacings therebetween are controlled, and the quantity of heat supplied from the burners 9 to the heat affected zones is controlled. According to this method, the cooling rate of the weld heat affected zones is controlled, and the hydrogen erosion resistance in the joint part in a high temp. high pressure hydrogen environment is improved. |
