METHOD OF PREVENTING STRESS CORROSION CRACKING IN MACHINES OR MACHINE PARTS MADE OF AUSTENITIC CAST IRON

摘要

Austenitic cast iron has excellent corrosion resisting properties and has been preferentially used in machines or machine parts intended for handling corrosive fluids such as seawater. Cases, however, have been reported of machines or machine parts made of austenitic cast iron failing after they had been put to prolonged service at relatively low temperatures. The present inventors have located stress corrosion cracking as the cause of this failure. The present invention therefore provides a method of preventing the occurrence of such stress corrosion cracking in machines or machine parts made of austenitic cast iron by subjecting them to cathodic polarization, such cathodic polarization preferably being such that the applied potential is at least 50 mV more base (less noble) than the stabilized natural potential.