| Title |
A Study on the Carburization of Plasma Sprayed Wc - 12%Co Coatings |
| Authors |
이홍주(Hong Joo Rhee); 김한삼(Han Sam Kim); 김수식(Soo Sik Kim) |
| Abstract |
Tungsten Carbide(WC) coatings were formed on mild steel substrates using the plasma spray process. As a mean to enhance the mechanical properties such as microhardness and wear resistance, as-sprayed coatings were annealed and then subsequently were subjected to the carburization under methane and hydrogen atmospheres. When the heat treatment was carried out under the hydrogen atmosphere, the amounts of WC phase were decreased and the amounts of α-W₂C and W phase were increased with the increase of temperature, which leaded to a slight reduction of the microhardness. In case of the carburization under methane atmosphere, the microhardness of the coatings was increased with the increase of temperature and show the highest value of 1540Hv at 1100℃. The wear resistance also was increased with the increase of the carburization temperature. The wear resistance of the coatings heat treated at 1100℃ were 17 times higher than the as-sprayed coatings. The increase of methane concentration at constant temperature at 900℃ showed the improvement of the microhardness and the wear resistance of coatings. The highest microhardness and wear resistance obtained at the methane concentration of 11%. |