Wear behavior of MIG manufactured 12Cr-xC (x=0.3, 0.4) hardfacings under different temperatures and loads

Metal inert gas (MIG) hardfacing technology has developed high-performance materials on carbon steel, which exhibit superior thermal wear resistance linked to Cr and C contents. In this study, the 12Cr-xC (x = 0.3, 0.4) hardfacings were manufactured by the MIG method, and the corresponding wear behavior on different loads and temperatures was characterized. The results revealed that the 12Cr-xC hardfacings exhibited good forming quality, with microstructure consist of martensite matrix, retained austenite, varying shape of the martensite-austenite continent (M/A), and a small number of carbides. The hardness reaches 483.1 and 520.3 HV0.2. The coefficient of friction (COF) of the 12Cr-xC hardfacings showed a range of 0.27-0.43 and decreased with temperature increased from 150 degrees C to 300 degrees C at 200 N. The 12Cr-xC hardfacings exhibited a good wear resistance and the wear loss rates at a low level (10(-5) mm(3)/(Nm)). The SiC balls' worn morphology is irregular, with abrasive wear and embedded oxide debris. Adhesive wear occurs under specific conditions, with a low wear loss rate compared to hardfacings. At 150 degrees C, 12Cr-xC hardfacings exhibit low W-hardfacing/W-ball (4-11), with abrasive mechanisms. Higher loads lead to more pronounced sacrifice of SiC balls, with abrasive wear and oxides covering the worn surface at 300 degrees C, with tribochemical reactions being the dominant mechanism.