Oxidization resistance of Ni76Cr19AlTi valve alloy at temperatures under operating mode of heavy-duty engines

The oxidization resistance of the Ni76Cr19AlTi alloy was studied by a static oxidization experiment at 600-800°C. The results show that the oxidation behavior of the alloy can be explained by a kinetic equation: (δm/S)2 = Kpt + C, where Kp is a kinetic constant of the nickel-base alloy. The higher the experimental temperature, the higher the value of Kp. It is discovered that the microstructure of the oxide scales is compact and the thickness of it is less than 10 μm. The oxidization of the alloy is in the first grade. It is also found that the oxide scales are mainly composed of Cr2O3 and TiO2. Chrome and titanium react more easily with oxygen at temperatures under the operating mode.