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用Fe_2O_3:Fe:Al_2O_3=1:1:1混合粉末,对20、20Cr、20Cr2Ni4、40Cr和GCr15五种钢进行了860～1100℃×8～80h内氧化处理,对其内氧化动力学进行了研究。研究结果表明:(1)钢的内氧化动力学遵守抛物线规律;(2)内氧化速度随内氧化温度的升高、钢中合金元素(主要是铬)和碳含量的降低而增大;(3)初始晶粒越小,内氧化速度越大;(4)内氧化过程中氧的晶界扩散发挥着重要作用;(5)试样表面氧化物覆层对内氧化速度有阻碍作用。这种阻碍作用表现在内氧化初期。
The internal oxidation kinetics of 20, 20Cr, 20Cr2Ni4, 40Cr and GCr15 steel were studied at 860 ~ 1100 ℃ for 8 ~ 80h with Fe_2O_3: Fe_Al_2O_3 = 1: 1: the study. The results show that: (1) The internal oxidation kinetics of steel obeys the parabolic law; (2) the internal oxidation rate increases with the increase of internal oxidation temperature and the decrease of alloying elements (mainly chromium) and carbon in steel; ( 3) the smaller the initial grain size, the greater the internal oxidation rate; (4) the oxygen diffusion during grain boundary diffusion plays an important role; (5) the oxide coating on the sample surface has an impediment to the rate of internal oxidation. This impeding effect is manifested in the initial period of internal oxidation.