STUDY ON THE PHASE COMPOSITION OF THE COATING FORMED FROM WC-12Co POWDER USING HVOF SPRAYING METHOD
This paper presents the results of determining the phase composition of coatings formed by WC-12Co powder using the HVOF spraying method on the inner surface of C40 steel pipes. The spraying parameters were set to investigate the phase transformation of the coating, including the spray distance (L), powder feed rate (P), and relative motion speed between the nozzle and the substrate surface (V). The influence of temperature and spraying parameters on the received energy and the impact duration is the main cause of the WC phase transformation, which leads to changes in the coating hardness compared to the original material. The results showed that some WC components were transformed into W, W2C, and Co4W2C. The coating hardness tends to decrease correspondingly with the decrease in the WC content in the coating. Determining the phase transformation effect is the basis for identifying and adjusting the appropriate transformation trend to limit the transformation, ensuring high hardness and wear resistance of the WC- 12Co spray coatings.
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