Erosive Effects of High Pressure and High Temperature Gases on Steel

Abstract

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.

Erosion behavior of Ni-based coating under high-speed hot airflow

“…The erosion test was performed using a modified pressure-vented vessel designed by the authors [5,24,25]. The general structure of the device is shown in Figure 1.…”

“…The alloy undergoes a compositional transformation of carbides caused by the migration of Cr under thermal cycling conditions [20], and cracking due to the embrittlement of crystal grains at low temperature under the action of thermal stress during the thermal cycling between low-temperature and high-temperature regimes [21][22][23]. The hightemperature airflow erosion caused by propellant combustion is not a single erosion process, but a synergistic effect of various factors, including thermal shock, heat flow erosion on the surface of the material and possible chemical erosion [24], thus the erosion process and degradation mechanisms are also more complex.…”

Erosion--Corrosion

“…Moller (1973) has predicted that gas stream velocity in turbines at 750 C gives a threefold increase in rate of metal loss of Nimonic 80A (Ni-20Cr-5maxFe-2maxCo-2.5Ti-l.2Al-0.lmax C). Alkidas et al (1976Alkidas et al ( , 1977 have studied the E-C of AISI 4340 steel in pressurized gases (O-, H_, CO-, CO and N«) at 3000°K and found that material loss is greatest in oxygen containing gases.…”