TY - GEN
T1 - Corrosion rate and oxide scale characteristics of austenitic alloys in supercritical water
AU - Watanabe, Yutaka
AU - Daigo, Yuzo
PY - 2006/1/1
Y1 - 2006/1/1
N2 - Corrosion properties were investigated on stainless steels and Ni base alloys in supercritical water containing O.01mol/kg-H2SO4 at 400°C/30MPa as a function of oxygen concentration ranging from 3ppb to 800ppm. Alloys with high Fe content showed an interesting contrast in corrosion property in sulfuric acid-containing supercritical water between at the high oxygen condition (800ppm) and at the lower oxygen conditions (3ppb and 8ppm). At 8ppm of oxygen concentration or lower, corrosion rate was a unique function of Cr content of the alloys including both Ni base alloys and stainless steels. However, corrosion resistance of the iron-based alloys (316 stainless steels) was remarkably improved when oxygen concentration was increased up to 800ppm. Corrosion rate of alloy C-276, which contains 5.7% of iron, was also somewhat reduced under the high oxygen condition, while corrosion rate of the other "iron-less" Ni base alloys was accelerated as oxygen level was increased. Characteristics of oxide scales, in terms of chemical composition and compound structure, have been examined in connection with the corrosion properties of the alloys.
AB - Corrosion properties were investigated on stainless steels and Ni base alloys in supercritical water containing O.01mol/kg-H2SO4 at 400°C/30MPa as a function of oxygen concentration ranging from 3ppb to 800ppm. Alloys with high Fe content showed an interesting contrast in corrosion property in sulfuric acid-containing supercritical water between at the high oxygen condition (800ppm) and at the lower oxygen conditions (3ppb and 8ppm). At 8ppm of oxygen concentration or lower, corrosion rate was a unique function of Cr content of the alloys including both Ni base alloys and stainless steels. However, corrosion resistance of the iron-based alloys (316 stainless steels) was remarkably improved when oxygen concentration was increased up to 800ppm. Corrosion rate of alloy C-276, which contains 5.7% of iron, was also somewhat reduced under the high oxygen condition, while corrosion rate of the other "iron-less" Ni base alloys was accelerated as oxygen level was increased. Characteristics of oxide scales, in terms of chemical composition and compound structure, have been examined in connection with the corrosion properties of the alloys.
KW - Austenitic alloys
KW - Corrosion
KW - Nickel base alloys
KW - Oxide scale
KW - Stainless steel
KW - Supercritical water
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U2 - 10.4028/0-87849-409-x.213
DO - 10.4028/0-87849-409-x.213
M3 - Conference contribution
AN - SCOPUS:37849028032
SN - 9780878494095
T3 - Materials Science Forum
SP - 213
EP - 220
BT - High-Temperature Oxidation and Corrosion 2005 - Proceedings of the International Symposium on High-Temperature Oxidation and Corrosion 2005
PB - Trans Tech Publications Ltd
T2 - International Symposium on High-Temperature Oxidation and Corrosion, ISHOC-05
Y2 - 30 November 2005 through 2 December 2005
ER -