Improving the technology of nitridation by the electro-spark alloying method

Abstract

The work shows studies aimed at developing methods for protection of structural steels on the example of steels 20 and 40, from wear, using the electricity spark alloying (ESA), by applying the nitrogen-like mixture on the treated surface with subsequent vanity of steel electrode appropriate to the material of the workpiece. To increase the thickness of the surface layer and the best adhesion of the coating is offered in front of the ESA electrode-tools made of steel of the corresponding brand, to form a mold of aluminum, using an electrode from the aluminum bar of the brand of blood pressure. Metrolographic studies were performed and the distribution of microtrandomness in the coating. Studies have shown that nitrogen -containing coatings consist of a "white" layer ", which smoothly goes into the diffusion zone and base metal. The obtained coatings have the highest thickness of "white layer" 110-130 microns. The results of the study of the micro-hardness of the obtained nitrogen-containing coatings indicate an increase in hardness to 9700-9910 MPa. The phase composition of nitrogen coatings is represented by a alloy solid and cubic iron nitride, aluminum dissolves in nitride and ferrite. The considered methods of application of nitrogen -containing coatings can be used to strengthen the surface of responsible parts and elements of pumping and compressor equipment: end surfaces of rings, for protective bushings; piston machines, mechanisms that have increased wear of the product, etc. Keywords: electro-spark alloying, microstructure, nitriding, steel, phase analysis.