Erosive Effects of High Pressure and High Temperature Gases on Steel

An experimental study is being conducted to determine the thermochemical mechanisms by which short duration pulses (1 to 2 ms) of high pressure and temperature gases erode steel. A ballistic compressor is used to generate the desired test gas conditions. The erosion of steel by oxygen-containing gases (e.g., air, O2/N2 mixtures) was found to be controlled by surface chemical reactions of oxygen. The erosion is linearly proportional to the oxygen mole fraction of the O2/N2 mixture. SEM examination of surfaces eroded by air, H2 and CO showed the formation of scales resulting from gas/surface interactions. It is proposed that, in general, erosion of steel results from the rapid formation of oxides on the surface followed by the removal of the oxides by the aerodynamic forces of the flow.