Abstract: To study the effect of composition adjustment under different heating processes on the structural characteristics, micro-morphology, and mechanical properties of the oxide scale,taking 54SiCrV and 65SiCrV steels as research objects, high-temperature oxidation tests were conducted to investigate the microstructure characteristics and phase composition of iron oxide scales generated by the two steels under different high-temperature oxidation conditions. The easy peeling characteristics of iron oxide scales were studied using nanoindentation. The results indicated that the H/E ratio of 54SiCrV steel was higher than that of 65SiCrV steel under the conditions of process 2, 4, 5, 6, 7, 8, that was, the compactness of the innner layer of iron oxide scale structure of 54SiCrV steel was higher than that of 65SiCrV steel under these high-temperature oxidation process conditions. The iron oxide scales of both experimental steels were mainly composed of oxides such as Fe₂O₃、Fe₃O₄、FeO、Fe₂SiO₄ and FeCr₂O₄. The oxide scale of both types of steel showed obvious layering phenomenon, with a denser inner layer structure, a looser middle layer, and a thinner outer layer. The inner layer of iron oxide scale was mainly composed of a Fe₂SiO₄/FeCr₂O₄/FeO mixed layer. The outermost layer of iron oxide scale was consistent with the typical characteristic structure of iron oxide scale, mainly composed of Fe₂O₃ and a small amount of Fe₃O₄. The intermediate layer of iron oxide scale was mainly composed of Fe₃O₄ and also contained a small amount of FeO. Under process 7 conditions, the oxide scale of 65SiCrV was more porous and porous than that of 54SiCrV, making it easier to remove in subsequent high-pressure water descaling.