| 摘要 |
PURPOSE:To improve the hardness of a weld zone by adding 1 or >=2 kinds of Ti, Zr, Nb, Hf and Ta to a molten pool at the time of welding high C steels containing a specific C content by the high energy beam welding. CONSTITUTION:The high C steels are welded by the high energy beam such as a laser beam, etc., so that deposited metal after welding contains 0.7wt.% C. At this time, the welding is performed while supplying or >=2 kinds of Ti, Zr, Nb, Hf and Ta in a shape of powder or foil to the inside of the molten pool formed during welding. These elements are the intense carbide forming elements and at the time of solidifying, these elements are combined with C of a molten part to form a carbide. By this method, the C quantity of solid solution in the deposited metal decreases and the residual austenite quantity is reduced. Accordingly, the occurrence of a crack on the weld zone is prevented and the hardness of the weld zone is improved. |
