INVESTIGATION OF WEAR RESISTANCE OF PROTECTIVE COATINGS UNDER CONDITIONS OF HYDRO ABRASIVE WEAR

摘要

Increase of service life of the drill bits with protective coatings, operating under conditions of abrasive, erosion and corrosion wear, is the most relevant problem in Ukraine. Aim of present work is to study wear resistance of the protective coatings under conditions of hydroabrasive wear. The investigation of wear resistance was made on the protective coatings, containing tungsten carbides, TeroCote 7888T, Diamax M and relite LZ-11-7, being arc deposited on steel45, under conditions of abrasive wear. It is determined that wear resistance of relite LZ-11-7 and Diamax M composite alloys, consisting of Fe-based reinforcing particles (fused spherical and crushed tungsten carbide), has selective character and insignificant dependence on properties and hardness of a matrix. Application of Ni-based composite alloy TeroCote 7888T (split tungsten carbide) provides for efficient protection under conditions of hydroabrasive wear. At room temperature the wear resistance of the protective TeroCote 7888T coating 15 and 2 times exceeds the wear resistance of relite LZ-11-7 and Diamax M, respectively. This alloy allows increasing service life of the protective coatings of reconditioned defect areas of drill bits' bodies, which operate under heavy conditions of corrosion-abrasive wear.