Three different techniques have been used to study the behavior of 13Cr alloy in a flowing CO2 saturated NaCl brine containing sand particles, namely weight loss, thickness loss and electrochemical techniques. The penetration rates by weight loss for erosion-corrosion tests were 2 to 3 times the pure erosion rate for similar sand concentrations for both single phase and multiphase flow. However for the single-phase flow conditions the erosion-corrosion penetration rates may be seen as acceptable taking into account the high levels of sand used in the testing. For higher flow velocity conditions where the pure erosion component might be higher, a factor of 2 to 3 times higher for erosion-corrosion may
represent a serious problem. The current investigation suggests that the 13Cr specimen does not return to a completely passivated state as long as the system is sufficiently erosive and as a result, a synergistic
effect between erosion and corrosion is exhibited. In most cases there is likely a competition between the protective film removal due to mechanical erosion and the film healing. The mechanistic model of
this competition may depend on the concentration and distribution of sand, flow pattern, fluid flow velocities, geometry and enviromental factors. An erosion-corrosion threshold for 13Cr based strictly on
flow velocity may not emerge from research with this alloy. More likely the erosion-corrosion behavior will be linked more closely to erosivity and environmental conditions.