Erosion-corrosion Behavior of a High Strength Low Alloy Steel in Flowing 3.5%NaCl Solution
Erosion corrosion behavior of a newly developed high strength low alloy(HSLA)steel in flowing 3.5%NaCl solution was systematically investigated via a home-made rotating erosion device,mass loss measurement,electrochemical impedance spectroscopy and potentiodynamic polarization curve measurement,as well as macroscopic/microscopic characterization of corrosion morphology and Raman spectroscopy.The results revealed that the mass loss of the HSLA steel in flowing 3.5%NaCl so-lution exceeded that in static immersion test by over 10 times.Failure of the HSLA steel in both static im-mersion and dynamic erosion conditions exhibited three distinct stages.Degradation of the HSLA steel in static immersion conditions primarily manifested in the second and third stages.In contrast,the corrosion resistance of the HSLA steel in dynamic erosion conditions rapidly declined in the first stage.Flow ero-sion may hinder the formation of a stable corrosion product scale of α-FeOOH.The relevant accelerating corrosion mechanism may primarily be ascribed to the following two aspects:accelerating the mass trans-fer of O2,Cl-and other species,and compromising the passivation film as well as the integrity of the cor-rosion product film.