Pitting Corrosion and Corrosion Behavior of Domestic Nuclear Safe Grade 2 and 3 Heat Exchanger Tubes in Simulated Nuclear Island Waste Residue Environment

Imported 304L was used in nuclear safe grade 2 and 3 heat exchanger tubes in nuclear power plants and domestic materials are used in new built plants.In simulated actual running environment,pitting corrosion and stress corrosion cracking (SCC) of domestic 304L in nuclear island waste residue environment were studied and evaluated.Results showed that critical FeCl3 concentration for pitting corrosion was between 0.1% and 0.5%.Polarization curves showed that the corrosion potential increased with reducing Cl- concentration.Five hundred hours experiment was performed in autoclave with simulated nuclear island waste residue environment of H3BO3＋NaOH＋Cl- by using reverse U-bend samples and the results showed that SCC did not appear.