The kinetics of duplex scale formation on 18/8 type stainless steel

摘要: A previous model of duplex scale growth on 18/8 stainless steels based the formation an impervious barrier at hemispherical alloy grain boundaries has been extended to consider influence a finite healing layer rate. The analysis shows that true primary and secondary or parabolic rate constants can best be calculated from weight gain vs. square root time plots. Accurate determinations constant requires oxidation exposures factor 3 4 times greater than form complete oxide-metal boundary interface. Good agreement is found between present theory expeimental data gives simple extrapolation method for evaluation long-term metal losses oxide thicknesses.