MELT-THROUGH WELDING METHOD FOR HIGH ALLOY, STAINLESS STEEL AND CLAD STEEL THEREOF

摘要

PURPOSE:To prevent oxidation of the bead surface and a back bead part by flowing gas produced by mixing He with limited vol. ratio in Ar in limited quantity as shielding gas and flowing gas produced by mixing H2 with limited vol. ratio in Ar in limited quantity as back shielding gas to perform welding. CONSTITUTION:At the time of performing MIG welding of clad steel, 30-50l/min gas consisting of, by vol., 25-50% He and the balance Ar is flowed as the shielding gas and 10-20l/min gas consisting of, by vol., =10% H2 and the balance Ar is flowed a the back shielding gas and welding is performed by a pulse welding current. Since the He is mixed in the Ar as the shielding gas, spatters are reduced and the oxidation of the bead surface is prevented and corrosion resistance of a weld zone is improved. In addition, since the small quantity of H2 is mixed in the Ar as the back shielding gas, the oxidation of the back bead part is prevented and a joint part with stable performance is obtained.