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

Abstract

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 °C to 300 °C at 200 N. The 12Cr-xC hardfacings exhibited a good wear resistance and the wear loss rates at a low level (10-5 mm3/(N·m)). 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 °C, 12Cr-xC hardfacings exhibit low Whardfacing/Wball (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 °C, with tribochemical reactions being the dominant mechanism.