مشخصات پژوهش

In the present work, the hardfacing coatings were obtained by Oxy-acetylene welding with different Pre-heat temperatures. The dissolution phenomena of WC reinforcement particles with the formation of W2C eutectic phase and its effect on the wear resistance and the mechanisms were studied. The Ni/WC hardfacing samples were characterized by scanning electron microscope (SEM) coupled with EDXS line Scan, EDXS Spot and EDXS Map Scan, X-ray diffraction (XRD), micro-hardness measurements, solid particle erosion test (SPE) and pin on disk test. The results showed that the 600°C pre-heat and 300°C pre-heat were optimum temperatures in sliding wear and erosive wear applications respectively. By changing the impact angles in SPE test, the wear mechanisms gradually changed from ductile behavior to brittle one. Also, the wear mechanism changed from abrasive wear in a ploughing mod to brittle fracture because of the reduction in plasticity and fracture toughness.