The zinc layer can form a protective zinc carbonate layer in certain soils, providing anodic protection to the steel pipe substrate. However, this protective effect 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 on eight samples over a period of 3 to 6 years showed that six of them exhibited relatively low corrosion of the zinc layer. The zinc layer experiences the highest corrosion in alkaline soils with high electrical resistance and high water content.
Generally speaking, studies on the corrosion of galvanized steel pipes in various types of soil have shown that the average corrosion rate of the zinc layer on galvanized steel pipes is 1.56 to 280 grams per square meter per year.
