Abstract
In order to improve soil corrosion resistance of spheroidal graphite cast iron, the effect of alloying elements was investigated. Considering the mechanism of microbially influenced corrosion, the corrosion resistance was examined in acetic acid solution with small amounts of salts over the range of pH 2.5-5.0. Alloying elements have no effect on the corrosion resistance in the pH range of 3.5-5.0. Some alloying elements affect the corrosion rate, when the pH is less than 3.O. Sn greatly improves corrosion resistance. Cu, Mo and Ni also improve the corrosion resistance, if the pH is 2.75 or below. The corrosion resistance of spheroidal graphite cast iron containing Sn or Cu is superior to those of SUS403 and SUS430.
