Pb-SiおよびPb-Sb-Si合金の耐食性について

Abstract

The author systematically studied lead-silicon and lead-antimony-silicon alloys for explanation of their corrosion resistances to the flash test by H2SO4, and H2SO4, HCl and (NH4)2SO4 solutions. The experimental results were as follows: (1) In respect of the flash point, lead-silicon alloys were generally less resistant than lead, and lead, and lead-antimony-silicon alloys were superior to lead-antimony alloys. (2) The corrosion rate of lead-silicon alloys was remarkably changed in the range of 0.008∼0.017% of silicon contents reqardless of concentrations and temperatures of the used acid solutions, and this tendency corresponded with the mechanical properties of these alloys. In H2SO4 solutions, the corrosion resistance was improved generally. In HCl solutions, the resistance was improved in proportion to silicon contents, and in (NH4)2SO4 solution, the corrosion rate showed almost a constant value in spite of silicon contents. (3) The corrosion rate of lead-antimony-silicon alloys was remarkably changed in the range of 1% and less of antimony contents for each concentration and temperature of the used acid solutions, and its tendency corresponded with their mechanical propreties. In H2SO4 at 30° and 75°C. lead-antimony-silicon alloys showed better resistance than lead-antimony alloys, and in HCl and (NH4)2SO4, these ternaly alloys were improved in proportion to antimony contents in respect of corrosion resistance.