Flow accelerated corrosion of X65 steel gradual contraction pipe in high CO2 partial pressure environments

Flow accelerated corrosion (FAC) behavior of X65 steel gradual contraction pipe in high CO2 partial pressure environments was investigated by in situ dynamic high pressure electrochemical measurements with Ag/AgCl reference electrode in FAC loop and microscopic characterization analysis. The corrosion rates in dynamic high CO2 partial pressure environments are obviously enhanced compared with those in dynamic atmospheric pressure and static high pressure environments. The FAC mechanism at gradual contraction pipe in high pressure environments exhibits significant distinction from that in atmospheric pressure environments. The variation of corrosion rates is associated with the hydrodynamics at gradual contraction pipe. The presence of high CO2 partial pressure under fluid flowing accelerates rupture of corrosion product scales.