Effects of stabilizing treatment of protective rust layer and alloy design on corrosion behavior of weathering steels under high airborne salt condition

Effects of stabilizing treatment of protective rust layer and alloy design on corrosion behavior of weathering steels were investigated by long-term exposure tests under the high airborne salt condition of 0.29 mdd. The stabilizing treatment was effective to suppress penetration of chloride ion by forming protective rust layer on the steel surface at the initial period of exposure. However, the effect wore off by long-term exposure, and protective rust layer was replaced to the normal rust layer corresponding to the alloy composition under the given environment. This results clearly show that it is important to select the appropriate weathering steel which forms protective rust layer under the environment of use, even if the stabilizing treatment of protective rust layer is applied on the steel surface.