HIGH TEMPERATURE OXIDATION PERFORMANCE OF ALUMINIDE COATINGS

the 17th Annual Conference on Fossil Energy Materials

B. A. Pint ; Y. Zhang ; J. A. Haynes ; I. G. Wright

Others  :  http://www.netl.doe.gov/publications/proceedings/03/materials/manuscripts/Pint_m.pdf
PID  :  49008

来源: CEUR

【 摘 要 】

In order to determine the potential benefits and limitations of aluminide coatings, coatings made by chemical vapor deposition (CVD) on Fe- and Ni-base alloy substrates are being evaluated in various high-temperatureenvironments. Testing of coatings on representative ferritic (Fe-9Cr-1Mo) and austenitic(type 304L stainless steel) alloys has found that high frequency thermal cycling (1h cycle time) cansignificantly degrade the coating.Based on comparison with similar specimens with no thermal cyclingor a longer cycle time (100h), this degradation was not due to Al loss from the coating but most likelybecause of the thermal expansion mismatch between the coating and the substrate.Several coated Ni-base alloys were tested in a high pressure (20atm) steam-CO_2 environment for the ZEST (zero-emission steam turbine) program.Coated specimens showed less mass loss than the uncoated specimens after 1000h at 900°C and preliminary characterization examined the post-test coating structure and extent of attack.