Corrosion and Scaling on Carbon Steel and Galvanized Steel Pipe in Simulated Geothermal Water

Corrosion and scaling are common troubles in geothermal application.The geothermal water of a central plain region was simulated to examine its scaling trends as well as the corrosion and scaling behavior of 20# carbon steel and galvanized steel pipe at 50 ℃,65 ℃ and 80 ℃.The results showed that the corrosion products and scale formed on 20# carbon steel pipe surface were loose,leading to a fast corrosion rate,while the rust and scale formed on galvanized steel pipe surface were condensed,which could effectively reduce the corrosion rate in geothermal water at 50 ℃ and 65 ℃.Under the test condition at 80 ℃,the surface potential of galvanized steel pipes was more positive,the zinc film lost its cathodic protection role,thus accelerated the corrosion.