Oversight or New Insight? Comments on Several Recent Papers Studying High-Temperature Oxidation of Si-Containing Steels

Abstract

Recently, a group of researchers conducted experimental studies on the high-temperature oxidation behaviour of Si-containing steels and published a series of papers in several international journals. Many of the research “findings” in these papers were inconsistent and contradictory with previous results. Based on the different findings, it was claimed that they arrived at “new insights” to the oxidation behaviour of Si-containing steels and discovered a “new method” to reduce the oxide scale amount generated during reheating of Si-containing steels. After examining the experimental methods used, it was revealed that most of the “new findings” were likely the direct consequence of the use of a very low gas flow rate (30 mL/min) in their experiments. This resulted in an extremely low oxygen supply rate when the oxygen concentration in the experimental gas was low, which in turn limited the reaction rate that could be possibly achieved by gas–steel reaction if abundant gas had been made available. The kinetics results and scale thickness/structures thus produced were therefore misleading, which also led to the erroneous interpretation of the results. This paper comments on the main results presented in these papers and briefly discuss several fundamental issues related to the design of steel oxidation experiments.