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Affiliation of Author(s):材料科学与技术学院

Journal:RARE METAL MATERIALS AND ENGINEERING

Key Words:as-forged Incoloy825 alloy Al, Ti contents microstructure corrosion resistance

Abstract:Effect of varying Al and Ti contents of Incoloy825 alloy on the phase transformations was simulated by a thermodynamic modelling tool. The microstructure and corrosion morphology of Incoloy825 alloy were investigated by the optical microscope (OM), and scanning electron microscope (SEM). The Potentiodynamic polarization curves, electrochemical impedance spectroscopy and corrosion rate of the tested alloy were investigated by electrochemical workstation and static weight-loss method in 1, 3 mol/L HCl solutions. The results indicate that the microstructure of as-forged Incoloy825 is composed of gamma substrate and a small quantity of Ti(C, N) at the final forging temperature. With the increase of Al, Ti contents, precipitation volume of blocky Ti(C,N) increases gradually, and the grain is refined; corrosion current density increases gradually, corrosion resistance decreases significantly, and pitting of the tested alloy is easier to occur. Large, faceted Ti(C, N) particles in Incoloy825 alloy provide preferred sites for pit initiation in the chloride environments. With the increase of Al, Ti contents, corrosion products on the surface of the alloy become more porous, and the protection ability to matrix decreases.

ISSN No.:1002-185X

Translation or Not:no

Date of Publication:2018-03-01

Co-author:孙楠,温宸,lxq

Correspondence Author:刘子利,刘希琴,Liu Zili