The high-temperature oxidation of nickel-20 wt. % chromium alloys containing dispersed oxide phases

Influence of yttria additions on the oxidation behaviour of titanium prepared by powder metallurgy

“…In the case of high-temperature Fe-, Ni-and Co-base alloys containing elements which could promote the formation of protective oxide layers such as Cr or Al, fine yttria dispersions contribute to reducing the oxidation rate and enhancing the adhesion of the protective scale [6,7]. Also, the growth mechanism of the oxide scale in these alloys appears to be modified by yttria addition.…”

Improving Corrosion Behavior in SCWR, LFR and VHTR Reactor Materials by Formation of a Stable Oxide

“…It has been proposed that they reduce the amount of chromium needed to form Cr203, thus making it easier to form Cr203 in alloys containing lower chromium contents than would be necessary to form Cr203 [21]. Furthermore, it has been proposed that the ODS particles can serve as nucleation sites for the oxide and thus help form Cr203 [25].The formation of Cr 2 03 is important for corrosion resistance since it slows down the diffusion of oxygen and iron [13,14]. Second, yttrium has been shown to segregate at oxide grain boundaries thus inhibiting oxide grain growth and slowing down diffusion processes [10,21,25].…”

“…Furthermore, it has been proposed that the ODS particles can serve as nucleation sites for the oxide and thus help form Cr203 [25].The formation of Cr 2 03 is important for corrosion resistance since it slows down the diffusion of oxygen and iron [13,14]. Second, yttrium has been shown to segregate at oxide grain boundaries thus inhibiting oxide grain growth and slowing down diffusion processes [10,21,25]. This was also observed for the 9CrODS alloy by Chen et al and was used to explain the enhanced corrosion resistance ofthat alloy [10].…”

High Temperature Oxidation Studies on Alloys Containing Dispersed Phase Particles and Clarification of the Mechanism of Growth of SiO2

“…It has been known that the presence of small amounts of oxides or nitrides such as ThO., Y 0 3 , or TiN in Ni-Cr and Fe-Cr alloys affects extensively the .-oxidation behaviour of such alloys (5)(6)(7)(8)(9)(10)(11)(12). The oxidation rate is considerably decreased for alloys containing oxide or nitride dispersions and, additionally, scale adhesion to the underlying alloys is much improved.…”