Alternativní inhibitor pro chladicí roztoky na bázi chloridu vápenatého / An alternative inhibitor for calcium chloride-based cooling solutions

The paper studied potential substitutes to sodium dichromateacting as an inhibitor for calcium chloride-based coolingsolutions. Mixtures of anodic (molybdate, phosphate, silicate)and cathodic inhibitors and oxidizing substances facilitatingformation of a compact magnetite layer (nitrates, nitrites) wereused as alternatives. Effi ciency of the inhibitors was studied atfi rst through accelerated measurements of the polarization resistance.The inhibitors for long-term exposure tests were chosenbased on the measurements. The combination of “passivating”nitrate and ceric cation acting as the cathodic inhibitorseems to be ideal. This mixture shows a similar decline of thecorrosion rate as dichromate.