| 摘要 |
PURPOSE:To obtain a filling material with superior crevice corrosion resistance by adding specified ranges of Cr and Mo to Ni as a metallic base. CONSTITUTION:This filling material consists of, by weight, 10-50% Cr, 8-35% Mo, 0.5-4.5% Si, 0.5-4.5% B and/or <=25% Fe and the balance Ni with inevitable impurities. The lower limit or more of Cr is required to intensify the passivity and drop the m.p., yet more than the upper limit of Cr does not remarkably enhance the intensifying effect. Mo is very effective in preventing the crevice corrosion in seawater, and the amount of Mo required in a filled layer is more than several % in the matrix. Mo is, however, added by said necessary amount or more because a loss due to oxidation, evaporation and dilution with a parent metal is considered and the low-Mo matrix of the filling alloy contributes largely to the crevice corrosion resistance than the fine block phase. Practically, less than the lower limit of Mo does not produce the desired effect, and more than the upper limit of Mo does not remarkably enhance the effect. |
