Through the copper-copper sulfate method and double-loop electrochemical potentiokinetic reactivation technique(DL-EPR)

the intergranular corrosion susceptibility of Incoloy800 alloy was tested. The effects of sensitive temperature and sensitive time on intergranular corrosion susceptibility of Incoloy800 H alloy were investigated. The microstructure of the sensitized specimens

morphology and elements of the alloy after DL-EPR test were examined by optical microscope

scanning electron microscopy and X-ray energy dispersive spectroscopy

respectively. The results show that

the susceptibility of the Incoloy800 H alloy increased at first and then decreased when the sensitive temperature rose and the sensitive time prolonged

and the highest susceptibility was observed after sensitization at 750 ℃ for 4 h

the reactivation rate Ra reached 71.8%. At high temperatures

the carbide precipitated in grain boundary of the Incoloy800 H alloy and a chromium-depleted zone formed

resulting in intergranular corrosion tendency of the Incoloy800 H alloy. When the sensitive temperature and sensitive time exceeded a critical value

self-repair of chromium elements occurred in chromium-poor regions and the intergranular corrosion susceptibility reduced significantly.