| 摘要 |
PURPOSE: To provide a welding method of the high tensile steel by the high energy density beam to greatly improve the toughness of the weld metal as weld. CONSTITUTION: Welding is achieved using the low alloy high tensile steel having the composition consisting of one or more kinds of 0.001-0.10% sol.Al, <=0.0070% N, 0.003-0.07% Ti, 0.003-0.15% Nb, 0.003-0.15% V, 0.003-0.10% Ta, and 0.002-0.10% by irradiating the high energy density beam while the part to be welded is shielded by the atmosphere containing nitrogen whose partial pressure is 10-20kPa and the balance the inert gas. The atmosphere on the beam irradiating side contains no nitrogen, and the atmosphere on the opposite side may contain nitrogen. The performance of the weld zone of a steel structure a line pipe, etc., can be greatly improved. |
