Investigation of the Effects of HVOF Process Parameters on the Quality and Wear Properties of the Coating Tungsten Carbide on 4130 Steel

Previous studies have shown that thermal spraying methods on steels have extensive applications in various industries to increase high-quality wear-resistance coatings. One of these coatings, which is important in diverse industries and has been studied, is tungsten carbide. One of the methods of coating is the high-velocity oxygen fuel (HVOF) process. Scanning electron microscopy (SEM) was used to examine the microstructure of the coatings and also by examining SEM images from the lateral surface of the coated sample, the thickness and quality of the coating were examined. Additionally, X-ray diffraction (XRD) was used to determine the formed phases before and after the coating process and the results of the presence of WC and W6C2.54 carbides were confirmed.The wear test results showed that coated samples demonstrated higher wear resistance than the sample without coating (control). Meanwhile, the sample with spraying pressure of 7.2 Bar and a feeding powder rate of 72 g/min (W2) exhibited the best wear resistance among other coatings due to the more uniform distribution of tungsten carbide (WC) and less porosity. As a result, it was obtained that the spraying pressure in the process of HVOF process was more effective than the feeding rate of coating powders and a sample with the spray pressure of 7.2 Bar and powders feeding rate of 72 g/min (W2) was introduced as the optimal sample among all coatings with the highest abrasion wear resistance.