Na$sub 2$SO$sub 4$- and NaCl-induced hot corrosion of six nickel-base superalloys

Journal Article · Mon Dec 01 04:00:00 EST 1975 · Oxid. Met., v. 9, no. 6, pp. 507-528

OSTI ID:4014520

Bourhis, Y; John, C

The short-time hot-corrosion behavior of six industrial nickel-base superalloys was investigated with static deposits of Na$sub 2$SO$sub 4$ or NaCl or both in still air. The oxidation kinetics and scale morphologies were measured with traditional laboratory techniques--thermobalance, metallography, electron microprobe, and x-ray analyses. Susceptibility to hot corrosion was found to be correlated to the type of scale produced during simple oxidation. Alloys forming an Al$sub 2$$O$$sub 3$ scale were found to be susceptible to Na$sub 2$SO$sub 4$ deposits, independent of their chromium content. The quantity of Na$sub 2$SO$sub 4$ deposit dictated the nature of the attack and, under certain conditions, the refractory element alloy additions appeared to play an essential role. Alloys containing Cr$sub 2$$O$$sub 3$ or TiO$sub 2$ in the simple oxidation scale proved to be sensitive to NaCl attack. Again, the severity of the attack within the susceptible alloy group was not related to the chromium or titanium content. Although less intensive than the Na$sub 2$SO$sub 4$-induced hot corrosion, NaCl contaminations provoked extensive spalling. All of the hot- corrosion types encountered in this study were interpreted in the light of existing theories. (auth)

• Research Organization: Ecole Nationale Superieure des Mines de Paris, Corbeil-Essonnes, France
• NSA Number: NSA-33-026563
• OSTI ID: 4014520
• Journal Information: Oxid. Met., v. 9, no. 6, pp. 507-528, Journal Name: Oxid. Met., v. 9, no. 6, pp. 507-528; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

*NICKEL BASE ALLOYS-- CORROSION
*SODIUM CHLORIDES-- CORROSIVE EFFECTS
*SODIUM SULFATES-- CORROSIVE EFFECTS
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VERY HIGH TEMPERATURE