METHOD FOR REDUCING CORROSIVE CRACKING OF METAL Russian patent published in 2002 - IPC

FIELD: power engineering; nuclear reactor units and the like. SUBSTANCE: invention is aimed at providing continuity of protective coating to reduce corrosive cracking of reactor metal parts operating in water. Metal surfaces are covered with insulating material in the form of ceramic-structure film of lithium ferrite. Coating is applied by wet preservation method with preservation solution pH corrected between 10.0 <pH <0.5 including addition of hydrazine-hydrate and lithium hydroxide. In the course of operation continuity of said film is maintained by doping microscopic doses of lithium hydroxide at 6.9 <pH <9.6 and concentration of at 0<α<1. EFFECT: enlarged incubation period of corrosive cracking process ; provision for maintaining continuous coating throughout entire service period in absence of alkaline embrittlement.