Intergranular attack of low carbon steel in molten aluminum chloride
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Authors
Lu, Mingquan
Issue Date
2024-05
Type
Electronic thesis
Thesis
Thesis
Language
en_US
Keywords
Materials engineering
Alternative Title
Abstract
AISI 1018 carbon steel exhibits intergranular attack in molten aluminum chloride in actual engineering applications. To elucidate a corrosion mechanism explaining such a phenomenon,
corrosion exposure tests have been conducted to investigate the effects of materials processing,
chemical composition, and molten salt cations on the severity of corrosion. To that end, pure iron,
A106, and AISI 1018 carbon steel have been exposed to pure AlCl3 and AlCl3-FeCl3 melts in
normalized and as-received conditions. Additional tests have been done with longer corrosion
durations and with molten AlCl3-FeCl2 salt. A novel corrosion quantification methodology is
employed. Intergranular corrosion is observed in both 1018 and A106 carbon steels in all the salts
whereas pure iron only shows pitting. Normalization and cold work in the as-received condition
have varying effects on the corrosion depths of pure iron, 1018 and A106 carbon steels. In 1018,
relative to exposure to pure AlCl3, addition of FeCl3 significantly accelerates the corrosion rate
whereas addition of FeCl2 substantially modifies the corrosion morphology. The grain boundary
microchemistry of 1018 carbon steel is examined with in-situ fracture Auger spectroscopy where
molybdenum and carbon segregation are found, and a mechanism is proposed to explain the
present corrosion phenomenon.
Description
May2024
School of Engineering
School of Engineering
Full Citation
Publisher
Rensselaer Polytechnic Institute, Troy, NY