The adhesion strength of the thermal spray powder coating with the surface of steel 45

Abstract

Problem. Improving the performance of materials can be achieved by changing the condition and properties of their surface by flame spraying. It is relatively simple to apply coatings on any limited surface area of a product made from a wide variety of materials using this method. Goal. The goal is improving of the methods of flame spraying and studying the influence of the degree of surface roughness and the thickness of the coating on the adhesion strength. The object of the study is Steel 45. A powder was a nickel based alloy PG-10Н-01 for the application of a flame coating. Methodology. The results are obtained on the basis of a bead-blasting surface treatment. The surface roughness of the steel was investigated using profiler – profile meter 252. Experimental strength tests were carried out on a wipe using glue. Results. It has been established that spraying at a right angle corresponds to the optimal mode of applying a gas-fired coating; surface preheating temperature ≈ 1500 С; the distance from the cut of the nozzle of the burner to the metal surface is 75–250 mm; spraying speed 130– 170 m/s. The adhesion strength of the coating with steel 45 increases with a surface roughnes and with a decrease in the thickness of the coating. It is necessary to apply a flame coating with thickness h ≤ 200 μm and a roughness parameter Ra ≥ 12,5 μm to increase the adhesion strength. Originality. For the first time the parameters of gas-flame spraying of such objects were established. The adhesion strength of the coating with steel 45, the degree of surface roughness and the thickness of the coating PG-10Н-01 were analyzed. Practical value. The obtained results can be used for improving the gas-flame spraying technology to increase the durability of machine parts.