Zinc coatings can form a protective zinc carbonate layer in certain types of soil, providing anodic protection to the steel pipe substrate. However, the effectiveness of this protection varies depending on the properties of the soil. According to relevant data, the pH value of soil ranges from 4.3 to 9.2. Experiments conducted over a period of 3 to 6 years using 8 samples showed that 6 of them exhibited minimal corrosion of the zinc coating. The highest corrosion of zinc coatings occurs in alkaline soils with high resistivity and high moisture content.
Generally speaking, studies on the corrosion of galvanized steel pipes in various soil types have shown that the average corrosion rate of zinc coatings on galvanized steel pipes is 1.56 to 280 grams per square meter per year.
