METHOD POLYURETHANE COATING OVER HVOF COATING FOR COMBATING EROSION OF HYDRO TURBINE COMPONENTS

摘要

The present invention relates to a method of polyurethane coating over HVOF coating for combating erosion of hydroturbine components. The method comprising the steps of applying a high velocity oxy fuel (HVOF) coating; then an intermediate metallic coating of Ni-AI using wire are spray process which is applied on the said HVOF coated surface to improve the surface roughness of the said coated surface; then an organic based primer is applied on the surface to get better adhesion followed by application of polyurethane coating layer which is produced by mixing the resin and hardener with an appropriate ratio.