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Holcomb, Gordon R

Publications and source records attributed to Holcomb, Gordon R.

High Pressure Steam Oxidation of Alloys for Advanced Ultra-Supercritical Conditions

A steam oxidation test was conducted at 267 ± 17 bar and 670°C for 293 hr. A comparison test was run at 1 bar. All of the alloys showed an increase in scale thickness and oxidation rate with pressure, and TP304H and IN625 had very large increases. Fine-grained TP304H at 267 bar behaved like a coarse grained alloy, indicative of high pressure increasing the critical Cr level needed to form and maintain a chromia scale. At 267 bar H230, H263, H282, IN617 and IN740 had kp values a factor of one–to-two orders of magnitude higher than at 1 bar. IN625 had a four order of magnitude increase in kp at 267 bar compared to 1 bar. Possible causes for increased oxidation rates with increased pressure were examined, including increased solid state diffusion within the oxide scale and increased critical Cr content to establish and maintain a chromia scale.

Steam, Oxidation, Superalloy, Pressure, Advanced U↗

Fireside Corrosion in Oxy-fuel Combustion of Coal

Oxy-fuel combustion is burning a fuel in oxygen rather than air for ease of capture of CO 2 from for reuse or sequestration. Corrosion issues associated with the environment change (replacement of much of the N 2 with CO 2 and higher sulfur levels) from air- to oxy-firing were examined. Alloys studied included model Fe–Cr alloys and commercial ferritic steels, austenitic steels, and nickel base superalloys. The corrosion behavior is described in terms of corrosion rates, scale morphologies, and scale/ash interactions for the different environmental conditions. Evidence was found for a hreshold for severe attack between 10 -4 and 10 -3 atm of SO 3 at 700ºC.

01 COAL, LIGNITE, AND PEAT↗