Thermal Shock and High Temperature Wear Behaviors of SHM1302 Hard-Faced Layer

To evaluate the high temperature application range of SHM1302 hard surface layer， the thermal shock resistance and high temperature wear resistance of SHM1302 hard surface layer were tested respectively， and the thermal shock and high temperature wear behavior of hard surface layer were investigated by X-ray diffraction (XRD)， scanning electron microscopy (SEM)， energy dispersive X-ray spectroscopy(EDX) and other characterization methods.In addition， the relationship between high-temperature oxidation / microstructure transformation and thermal shock / high-temperature wear behavior was established.Results showed that the initiation and propagation of SHM1302 thermal shock cracks were affected by the combined effects of stress and oxidation， and the cracks mainly propagated along the interface between matrix and carbide.With the thermal shock cycle，the formation of harmful phase of MnFe2O4 in the oxide film and the precipitation of (Fe，Cr)3C in the matrix promoted the expansion of thermal shock cracks.At 500 ℃， the hard surface had good high temperature wear performance.The wear at 600 ℃and 700 ℃was significantly increased by 1 244%and 1 596%compared with 500 ℃.When the wear temperature increased from 500 ℃to 600 ℃， the increase of oxidation rate and the formation of harmful phase MnFe2O4 were the key factors for the rapid decline of wear performance.Furthermore， the M ⇌A structure transformation at 700 ℃promoted the initiation of fatigue cracks and further accelerated the wear process.