Title

The Corrosion Behavior of Ni₃(Si,Nb) Alloys in Boiling 70 wt.% Sulfuric Acid

Abstract

Corrosion-resistant Ni3(Si,Nb) alloys are promising materials of construction for hydrogen-production systems based on the sulfur-iodine thermochemical cycle. In this work, the corrosion rates of three differentNi3(Si,Nb) alloys were measured in boiling 70 wt.% sulfuric acid and a three-stage corrosion mechanism was identified, based on the composition and morphology of surface scale that developed. The α(Ni) +β(Ni3Si) eutectic constituent of the alloy microstructure was selectively attacked by acid and, when present, is detrimental to corrosion resistance. The G-phase (Ni16Si17Nb6) is more passive than the β-matrix and seems to contribute to a lower steady-state corrosion rate.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Corrosion; Corrosion Rate; Corrosion Resistance; Hydrogen Production; Iodine; Nickel; Silicon; Sulfur; Sulfuric Acid; Alloy Microstructure; Corrosion Mechanisms; Hydrogen Production Systems; Materials of Constructions; Morphology of Surfaces; Ni-Si Alloy; Sulfur-Iodine Cycles; Thermochemical Cycles; Silicon Alloys; Ni-Si Alloys; Sulfur-Iodine Cycle

International Standard Serial Number (ISSN)

1059-9495

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2016 Springer Verlag, All rights reserved.

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