THE EROSION-CORROSION OF ALLOYS UNDER OXIDIZING-SULFIDIZING CONDITIONS AT HIGH-TEMPERATURE

Citation
Fh. Stott et al., THE EROSION-CORROSION OF ALLOYS UNDER OXIDIZING-SULFIDIZING CONDITIONS AT HIGH-TEMPERATURE, Wear, 186(1), 1995, pp. 291-298
Citations number
9
Categorie Soggetti
Material Science","Engineering, Mechanical
Journal title
WearACNP
ISSN journal
00431648
Volume
186
Issue
1
Year of publication
1995
Pages
291 - 298
Database
ISI
SICI code
0043-1648(1995)186:1<291:TEOAUO>2.0.ZU;2-5
Abstract
A whirling-arm erosion-corrosion rig has been designed and constructed to allow studies under gaseous conditions of high-sulphur, low-oxygen activities at high temperatures; these environments are pertinent in processes such as gasification of coal and catalytic cracking of oil. The system can operate at particle impact velocities up to 30 m s(-1), particle impact fluxes up to 1 g cm(-2) s(-1) and temperatures up to 800 degrees C. The particles are carried to the specimen chamber in a stream of nitrogen and mixed with hydrogen, hydrogen sulphide and, if necessary, water vapour to attain the required sulphur and oxygen acti vities. In this paper, results are presented for two commercial austen itic high-temperature alloys, 310 stainless steel and Alloy 800HT, dur ing impact erosion by 25 mu m alumina particles at velocities of 10-25 m s(-1) and particle fluxes in the ranges 0.06-0.16 g cm(-2) s(-1) an d 0.38-0.95 g cm(-2) s(-1) at 500 degrees C. The gaseous environment r esulted in the development of sulphide scales on the alloys during exp osures in the absence of the erodent particles. The erosion-corrosion damage was determined in terms of mean thickness-change measurements o btained every 5 h and overall metal-recession rates obtained by cross- sectional examination at the end of the 35 h or 70 h exposure periods. The results are discussed in terms of the synergistic interactions of growth of metal sulphides and removal of such phases by the impacting particles.