A novel surface active amine lay-up protection agent was developed

which can form a denseγ-FeOOH protection layer to isolate the corrosion factor from the metal so as to inhibit the corrosion.The property of this novel agent was tested and applied in protection of a sub-critical direct air-cooled boiler during the shutdown period.The laboratory measurement and actual application results show that

the protection film formed by this surface active amine was complete and dense

and its breakdown time by the acid copper sulfate was larger than 30seconds

which had good protection effect and had no harmful to the water vapor system and the condensate polishing resin.The chemical instruments can be operated normally during the dosing process.Moreover

the wash time during the unit start-up was shortened

which allowed the unit can be combined to the grid in advance.