Hot corrosion studies on Ni-base superalloy at 650°C under marine-like environment conditions using three salt mixture (Na2SO4+NaCl+NaVO3)

Mannava, Venkateswararao; Rao, A. Sambasiva; Paulose, Neeta; Kamaraj, M.; Kottada, Ravi Sankar

doi:10.1016/j.corsci.2016.01.008

Cited by 82 publications

(31 citation statements)

References 31 publications

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“…In this research, the salt mixture of 87.5 wt.% Na 2 SO 4 + 5 wt.% NaCl + 7.5 wt.% NaNO 3 was selected as a corrosive medium at elevated temperature to simulate the operation environment of marine gas turbine [31]. Therefore, the hot corrosion behavior of laser-repaired Inconel 718 alloy in a marine-like environment and the associated microstructural evolution were studied.…”

Section: Introductionmentioning

confidence: 99%

Hot Corrosion and Mechanical Performance of Repaired Inconel 718 Components via Laser Additive Manufacturing

Zhang

Zhuang

et al. 2020

Materials

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Hot corrosion is one of the crucial failure modes of Ni-based superalloy components operating at high temperatures, which inevitably affects the subsequent mechanical properties of the alloys. In this research, damaged Inconel 718 alloy components with a pre-made trapezoid groove are repaired using laser additive manufacturing technique, and the change mechanisms of the microstructure and tensile properties of the repaired Inconel 718 alloy due to the hot corrosion in the salt mixture of 87.5 wt.% Na2SO4 + 5 wt.% NaCl + 7.5 wt.% NaNO3 at 650 °C for different durations are investigated. The results show that oxidation and Cr-depletion occur on the repaired components due to the hot corrosion, and the corrosion products are mainly composed of Cr2O3, Fe3O4, and Ni3S2. The tensile strength and elongation of the as-repaired specimens are 736.6 MPa and 12.5%, respectively. After being hot corroded for 50 h, the tensile strength increases to 1022.9 MPa and elongation decreases to 1.7%. However, after being hot corroded for 150 h, both tensile strength and elongation of the repaired specimens drop to 955.8 MPa and 1.2%, respectively. The mechanical performance alteration is highly related to thermal effects instead of the molten salt attack.

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Section: Introductionmentioning

confidence: 99%

Hot Corrosion and Mechanical Performance of Repaired Inconel 718 Components via Laser Additive Manufacturing

Zhang

Zhuang

et al. 2020

Materials

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“…Meanwhile, the spectra of Na1s also shows the existence of Na 2 Cr 2 O 7 and Na 2 Cr 2 O 4 . However, Cr 2 O 3 and Na 2 Cr 2 O 4 cannot be volatilized at 900 °C, and they should be produced by decomposition of Na 2 Cr 2 O 7 [29]. The spectra of Ni2p indicates that the corrosion products contain NiO [24].…”

Section: Resultsmentioning

confidence: 99%

Corrosion Behavior of GH4169 Alloy under Alternating Oxidation at 900 °C and Solution Immersion

Liu

et al. 2019

Materials

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In this paper, the corrosion behavior of GH4169 superalloy under alternating oxidation (at 900 °C) and solution immersion (in 3.5% NaCl solution, 30 ± 1 °C) has been studied by SEM, XRD, XPS, and electron probe microanalysis (EPMA). The results show that the alternating environment increases the corrosion rate of GH4169. The reaction of NaCl and Cr2O3 generates various volatile and soluble corrosion products, such as Na2Cr2O7, CrCl3, Cl2, and Na2CrO4, at a high temperature. The destruction of the protective Cr2O3 film leads to the increase of defects in the oxide scale, promoting the formation of oxides, such as NiO and Fe2O3, and changes the composition and structure of the oxide film. After repeated iterations, the mixed oxides will result in the spalling of the oxide film because they can reduce the fracture toughness of the corrosion scale. Therefore, the corrosion is comprehensively intensified.

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“…The Fe-rich oxide layer formed on the surface would be very porous due to the evaporation of water vapor, FeCl 2 , CrCl 3 and NiCl 2 and the diffusion of HCl and Cl 2 . In addition, the evaporation of Na 2 Cr 2 O 7 was possible occurred in this case due to relatively high vapor pressure, 3,23,24) resulting in no detection of them in XRD analysis. Na 2 CrO 4 was not detected in XRD analysis, possibly due to the low volume fraction.…”

Section: Corrosion Behavior Of 304ss In Simulated Marinementioning

confidence: 92%

“…In addition, when turbine engines work in marine environments, salt from the atmosphere accumulates on turbine blades and the moist air with enough water vapor is assimilated in the machines at the same time, resulting in corrosion caused by both deposited salt and water vapor. 1) It is well known that the oxidation resistance of alloy can be remarkably deteriorated by the addition of NaCl 2,3) or water vapor 4,5) in air at high temperature. Therefore, in order to develop high corrosion-resistant alloys in marine environment, extensive studies have been conducted on investigating the corrosion mechanism of pure Fe, 6) Fe-Cr, 7) pure Cr, 8) 1Cr11NiW2MoV 9) and Ti60 10) alloys with solid NaCl deposits in water vapor at 500-700°C.…”

Section: Introductionmentioning

confidence: 99%

Corrosion Behaviour of TiC Particle-reinforced 304 Stainless Steel in Simulated Marine Environment at 650°C

Zhang

et al. 2019

ISIJ Int.

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Corrosion behaviour of 304SS and TiC-reinforced 304SS in simulated marine environment at 650°C, compared with that of 304SS in air, has been investigated. The corrosion of 304SS in marine environment is more severe than that in air due to the effect of NaCl and water vapor. For TiC-304SS, a finer microstructure and higher dislocation density formed by TiC addition accelerates chromium diffusion. The formation of TiO 2 by the oxidation of TiC possibly assists chromia nucleation and increases the adhesion of chromia scale. As a result, corrosion resistance is increased. However, the corrosion rate of 304SS-6TiC is faster than that of 304SS-2TiC and the possible reason to cause this is discussed.

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Hot corrosion studies on Ni-base superalloy at 650°C under marine-like environment conditions using three salt mixture (Na2SO4+NaCl+NaVO3)

Cited by 82 publications

References 31 publications

Hot Corrosion and Mechanical Performance of Repaired Inconel 718 Components via Laser Additive Manufacturing

Hot Corrosion and Mechanical Performance of Repaired Inconel 718 Components via Laser Additive Manufacturing

Corrosion Behavior of GH4169 Alloy under Alternating Oxidation at 900 °C and Solution Immersion

Corrosion Behaviour of TiC Particle-reinforced 304 Stainless Steel in Simulated Marine Environment at 650°C

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