Exploring high-temperature short-interval wear property of Fe-Cr-C-Si layers via hardfacing technology and followed laser heat treatment

Abstract

This study presents an integrated fabrication of Fe-Cr-C-Si hardfacing layers through gas metal arc welding (GMAW) coupled with a subsequent two-step laser heat treatment process, encompassing water cooling post-laser treatment and air cooling, followed by a systematic investigation of their intermittent wear behavior under varying temperature conditions. This finding underscores the remarkable bonding strength and intricate microstructural features of the Fe-Cr-C-Si hardfacing layers, which are further refined through laser heat treatment (LHT), resulting in heightened hardness. Comprehensive wear testing, conducted at two modes and different temperatures, unveils distinct Coefficient of Friction (COF) profiles, with the SiC counterpart exhibiting exceptional wear resistance. Post-wear analysis of the Fe-Cr-C-Si surfaces illuminates the interplay of tribochemical reactions, adhesion, and abrasion mechanisms. Notably, the wear resistance of hardfacing and LHT are outstanding, manifested by exceptionally low wear loss rates (×10⁻⁷). The wear loss rate of hardfacing is 65.7 % (400℃) and 39.71 % (500℃) higher than the wear loss rate of the LHT specimens at different temperatures, a nuanced influence of temperature on oxide composition and wear behavior. At 400°C, an extended running-in period is observed, whereas, at 500°C, substantial Cr₂O₃ and SiO₂ oxides are prominent. Initially, a reduction in oxide debris hints at a shortened running-in phase; however, as the wear intervals extended, debris ejection intensified due to the three-body abrasive effects of oxide fines.