Technology of Obtaining and Mechanical Processing of Resistant Powder Coatings of Ni-Mo-Al System

Abstract

The results of a technological process development for obtaining a wear-resistant powder coating of Ni-Mo-Al system, applied by cold gas-flame spraying to the surface of a critical unit of compressor equipment in the oil and gas industry, within the framework of repair production are presented. Using scanning electron microscopy (SEM), the features of the structure and distribution of alloying elements in the coating are determined. The authors rationalized mechanical processing of the surface layer in order to obtain minimum roughness of the working area of the compressor cylinder. It is shown that the sprayed coating of Ni-Mo-Al system has a satisfactory adhesion strength in the range of 30-50 MPa, microhardness of 200-210 HV, which provides an increased running-in rate of piston rings of 6-10 mm3/Nm when operating the compressor in the temperature range of 350 - 400 °C. The parameters of finishing machining process of the finished coating are worked out, which makes it possible to ensure the minimum possible roughness of the coating of Ni-Mo-Al system in the range of 0.08-0.15 Ra in order to reduce wear of the working surface and extend service life.