アルミニウムに孔食を発生させうる人工水におよぼすSO₄^2-*,HCO₃^-**の影響

抄録

In this study, coexisting effects of Na₂SiO₃ and Na₃PO₄ upon the artificial water LSW₁ (capable of generating pit on aluminium immersed in waters) found by the authors were investigated. Related to the permanent hard water, effect of SO₄^2- ion upon LSW₁ was studied, and very complicated relations were found. Related to the temporary hard water, effect of Ca(HCO₃)₂ upon LSW₁ was studied. Coexisting effect of the permanent (CaSO₄) and the temporary [Ca(HCO₃)₂] waters was studied.
By variations of coexisting ratio of SiO₃^2-(or PO₄^-3) and Ca(HCO₃)₂, pH of the natural waters becomes either alkali or acid. And in each pH side there existed a unique pitting characteristic.