Effect of temperature on corrosion and scaling of galvanized steel pipe in simulated geothermal water

Steel pipe corrosion and scaling is a universal problem in the geothermal water environment. Scanning electron microscopy (SEM), energy dispersion spectrometry (EDS) and X-ray diffraction (XRD) were used to study the corrosion and scaling behavior of galvanized steel pipe in a simulated geothermal water environment with different temperatures. Results indicate that there are two kinds of microcosmic appearance (″ball″ like and ″needle″ like) on the surface of galvanized steel pipe in the forepart of experiment. The shape of corrosion and scaling crystals is different at different temperatures. The main components of corrosion and scaling products are Zn(OH)₂, ZnO, CaCO₃ and MgCO₃, and they could restrain the further corrosion of galvanized steel pipe in the geothermal water. The area of corrosion pit of galvanized steel pipe is small at 50°C, and which is big at 65°C and 80°C. The corrosion and scaling of galvanized steel pipe accelerates as the temperature increases.