Comparative study on intergranular corrosion sensitivity of three nickel-based alloys

Nickel-based alloys, as one of the representatives of special Nickel-based alloys, as one of the representatives of special stainless steels, have high strength and excellent oxidation resistance and corrosion resistance. However, under specific environments, intergranular corrosion can occur easily. Intergranular corrosion is a localized corrosion phenomenon with great hazards, which can lead to sudden equipment failure. Therefore,this paper selects Inconel625, Inconel825, and Inconel690 as three kinds of nickel-based alloys for testing in ferric sulfate-sulfuric acid solution for 120 hours. The corrosion rate is calculated, and the corrosion rates of the three corrosion-resistant alloys are compared. The test results show that nickel-based alloys have good intergranular corrosion resistance. The anti-ferric sulfate-sulfuric acid intergranular corrosion performance of the three materials is ranked as follows: Inconel690, Inconel825, and Inconel625.