TheironrustphasesformedonIowalloysteelscontainingdifferentquantitiesofCrelementhavebeencharacterizedusingEPMA,Ramanspectroscopy,TEM,opticalmicroscopyetc.Theionselectivepropertiesofsynthesizedrustfilmswiththesamephaseconstituentastheatmosphericcorrosionproductswereinvestigatedusingself-madeapparatus.TheresultsshowedthatcorrosionlossofsteelsexposedinmarineatmospheredecreasedrapidlyastheCrcontentofthesteelwasincreased.Cr-containingsteelswerecoveredbyauniformcompactedrustlayercomposedoffineparticleswithanaveragediameterofseveralnanometers.InnerrustlayerofCr-containingsteel(2massfraction)wascomposedofα-CrxFel-xOOH,withCrcontentofabout5massfraction.Suchrustlayershowedcationselectiveproperty,andcoulddepressthepenetrationofCl-tocontactsubstratesteeldirectly.
