Simulated Occluded Corrosion Cell were used to study the changes of chemical sta te within the OCC of 304 stainless steel in neutral solution of 0.5mol· L -1 NaCl containing various organic ion concentrations at 50℃.Anodic po larizing occluded specimen was used to simulate reaction current between outer a nd inter of OCC.When organic anion was added into the bulk solution

it migra ted into OCC

and the migration quantity increased with concentration and time

while the migration rate decreased with the length of time.Organic anion was in competition with Cl - on migration.It can retard the migration of Cl - effectively above a certain concentration.The higher the concentration

the more effici ent it was.Organic anion can not retard pH fall but can fall multiples of Cl - enrichment effectively above a certain concentration.The migration quantity and migration rate of DBSAS were greater than that of SDS.