Corrosion and scaling on carbon steel and galvanized steel pipe in simulated geothermal water

Abstract; 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°C , 65°C and 80°C. 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 al 50°C and 65°C. Under the test condition at 80 °C, the surface potential of galvanized steel pipes was more positive, the zinc film lost its cathodic protection role, thus accelerated the corrosion.