Effect of Ti addition on high-temperature oxidation behavior of Co–Ni-based superalloy

Zhu, Ying‐xin; Li, Chong; Liu, Yong‐chang; Ma, Zongqing; Yu, Hongying

doi:10.1007/s42243-020-00379-z

Cited by 26 publications

(3 citation statements)

References 47 publications

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“…Titanium is known to be an oxygen active element [56], but its effect depends on prevailing conditions and the composition of the base alloy. At temperatures above 900 °C, Ti additions have been reported to enhance oxidation resistance of Co-Ni-based superalloys [57] and FeAl intermetallics [58], whereas Ni-based model alloys typically show faster scale growth with Ti additions at 800 °C [59][60][61]. The higher mass gain of the Ti-containing model alloys in the current study supports a Ti 4+ doping mechanism in Cr 2 O 3 .…”

Section: The Effect Of Ti Additionsupporting

confidence: 65%

A Tracer Study on sCO2 Corrosion with Multiple Oxygen-Bearing Impurities

et al. 2021

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Several modern power production systems utilize supercritical CO2 (sCO2), which can contain O2 and H2O as impurities. These impurities may degrade the compatibility of structural alloys through accelerated oxidation. However, it remains unclear which of these impurities plays a bigger role in high-temperature reactions taking place in sCO2. In this study, various model and commercial Fe‐ and Ni‐based alloys were exposed in 300 bar sCO2 at 750 °C to low levels (50 ppm) of O2 and H2O for 1,000 h. 18O-enriched water was used to enable the identification of the oxygen source in the post-exposure characterization of the samples. However, oxygen from the water did not accumulate in the scale, which consisted of Cr2O3 in the cases where a protective oxide formed. A 2wt.% Ti addition to a Ni-22%Cr model alloy resulted in the formation of thicker oxides in sCO2, while a 1wt.% Al addition reduced the scale thickness. A synergistic effect of both Al and Ti additions resulted in an even thicker oxide than what was formed solely by Ti, similar to observations for Ni-based alloy 282.

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Section: The Effect Of Ti Additionsupporting

confidence: 65%

A Tracer Study on sCO2 Corrosion with Multiple Oxygen-Bearing Impurities

et al. 2021

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“…However, for the K38G nanocrystalline coating, the value of the parabolic rate constant was about 6.14 × 10 −6 mg/cm 4 s, which was one order of magnitude larger than that of the NiAl and N5 coatings. This showed that the main oxide products on the K38G coating were not only α-Al 2 O 3 , but other oxides as well, like TiO 2 [ 34 , 35 , 36 , 37 ].…”

Section: Resultsmentioning

confidence: 99%

Effect of γ′ Phase Elements on Oxidation Behavior of Nanocrystalline Coatings at 1050 °C

Wang

Yang

et al. 2021

Materials

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To study the effect of γ′ phase elements on the oxidation behavior of nanocrystalline coatings, two comparable nanocrystalline coating systems were established and prepared by magnetron sputtering. The oxidation experiments of the nanocrystalline coatings on the K38G and N5 superalloys were carried at 1050 °C for 100 h, respectively. The chemical composition of the above coatings is the same as the substrate alloy, including the γ′ elements, such as Al, Ta, and Ti. After serving at a high temperature for certain periods, their oxides participated and then affected the oxidation behavior of the coatings. The Al2O3 scale can be formed on the N5 coating, which cannot be formed on the K38G coating. Tantalum and titanium oxides can be detected on the oxide scale, which ruin its purity and integrity.

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“…Titanium may be also considered for this role. Ti is often present in many superalloys, based on nickel [8,9] as well as on cobalt [10,11] and its role in the oxidation behaviour at high temperature of the concerned alloys can be important [12]. In presence of c arbon, titanium may lead to the formation of TiC carbides in nickel-based superalloys [13][14][15] as well as in cobalt-based superalloys [16].…”

Section: Introductionmentioning

confidence: 99%

Influence of Ti on the oxidation behaviour at 1250°C of chromia-forming alloys based on nickel and/or cobalt

Berthod

Wora

2023

Corrosion Engineering, Science and Technology

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Six {Ni,Co}-based alloys containing 25wt-%Cr, 0.4wt-%C and 1.6wt-%Ti were cast and subjected to metallographic characterisation before and after exposure for 70 h in air at 1250°C, the highest temperature at which these alloys may be used under low applied stresses. The alloys based mainly on nickel contain principally chromium carbides while TiC is the principal carbide phase in the alloys mainly based on cobalt. The oxidation resistance is the best for the alloys richer in nickel than in cobalt, but titanium has the same effect for all alloys, whatever the base element: after oxidation it is present as an external TiO 2 layer covering chromia. The presence of this outermost more (Ni-based alloys) or less thick (Co-based alloys) TiO 2 scale on the outer face of the external chromia scale, is expected to have a protective role against chromia volatilisation, phenomenon which can be very important at so high temperature.

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Effect of Ti addition on high-temperature oxidation behavior of Co–Ni-based superalloy

Cited by 26 publications

References 47 publications

A Tracer Study on sCO2 Corrosion with Multiple Oxygen-Bearing Impurities

A Tracer Study on sCO2 Corrosion with Multiple Oxygen-Bearing Impurities

Effect of γ′ Phase Elements on Oxidation Behavior of Nanocrystalline Coatings at 1050 °C

Influence of Ti on the oxidation behaviour at 1250°C of chromia-forming alloys based on nickel and/or cobalt

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