Correlation of High-temperature Steam Oxidation with Hydrogen Dissolution in Pure Iron and Ternary High-chromium Ferritic Steel

The high-temperature oxidation in air and steam at 923 K was examined with pure iron, Fe-10Cr and Fe-10Cr-0.08C (0~0.03)S steels. The amount of hydrogen dissolved into samples during exposure to steam was measured with thermal desorption spectroscopy (TDS). It was found that the amount of dissolved hydrogen was related closely to the steam oxidation resistance of the steels. In case of pure iron, the thickness of the oxide scale formed in steam at 923 K for 360 ks was comparable to that of the scale formed in air. On the other hand, in case of the Fe-Cr binary alloy and the ternary ferritic steel, the oxide scale was much thicker in steam than in air. It was found that the amount of the dissolved hydrogen was much larger in both the binary alloy and the ternary ferritic steel than in pure iron, and then it leads to the more accelerated oxidation rate in the ternary steels in steam.

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The Relationship between High-Temperature Steam Oxidation and Hydrogen Dissolution in High-Chromium Ferritic Steels

High-Temperature Oxidation and Corrosion 2005 - Materials Science Forum ◽

10.4028/0-87849-409-x.197 ◽

2006 ◽

pp. 197-204

Author(s):

K. Nagai ◽

Masaaki Nakai ◽

Tomonori Kunieda ◽

Yoshinori Murata ◽

Masahiko Morinaga ◽

...

Keyword(s):

High Temperature ◽

Steam Oxidation ◽

Ferritic Steels ◽

High Chromium ◽

High Temperature Steam ◽

The Relationship ◽

Hydrogen Dissolution

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Beneficial Effect of Impurity Sulfur on High-Temperature Steam Oxidation of High Chromium Ferritic Steels

High-Temperature Oxidation and Corrosion 2005 - Materials Science Forum ◽

10.4028/0-87849-409-x.147 ◽

2006 ◽

pp. 147-154

Author(s):

Yoshinori Murata ◽

Masaaki Nakai ◽

K. Nagai ◽

Masahiko Morinaga ◽

Y. Sasaki ◽

...

Keyword(s):

High Temperature ◽

Beneficial Effect ◽

Steam Oxidation ◽

Ferritic Steels ◽

High Chromium ◽

High Temperature Steam

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Beneficial Effect of Sulfur State on High-Temperature Steam Oxidation Resistance in High Chromium Ferritic Steels

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.45.865 ◽

2004 ◽

Vol 45 (3) ◽

pp. 865-869 ◽

Cited By ~ 4

Author(s):

Masaaki Nakai ◽

Yoshinori Murata ◽

Masahiko Morinaga ◽

Yasutoshi Sasaki

Keyword(s):

High Temperature ◽

Beneficial Effect ◽

Oxidation Resistance ◽

Steam Oxidation ◽

Ferritic Steels ◽

High Chromium ◽

High Temperature Steam

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Beneficial Effect of Impurity Sulfur on High-Temperature Steam Oxidation of High Chromium Ferritic Steels

Materials Science Forum ◽

10.4028/www.scientific.net/msf.522-523.147 ◽

2006 ◽

Vol 522-523 ◽

pp. 147-154 ◽

Cited By ~ 3

Author(s):

Yoshinori Murata ◽

Masaaki Nakai ◽

K. Nagai ◽

Masahiko Morinaga ◽

Y. Sasaki ◽

...

Keyword(s):

Solid Solution ◽

High Temperature ◽

Beneficial Effect ◽

Oxidation Resistance ◽

Steam Oxidation ◽

Ferritic Steels ◽

High Chromium ◽

Sulfur Effect ◽

High Temperature Steam ◽

Short Time

The effect of S in steels on high-temperature steam oxidation resistance was investigated with respect to the content and the state in high Cr ferritic steels. The beneficial sulfur effect on high-temperature steam oxidation resistance was verified in high Cr ferritic steels. It was considered that Cr was enriched in the vicinity of the segregated S on the specimen surface because of a strong affinity between Cr and S atoms, resulting in the easy formation of the passive Cr2O3 oxide layer on the surface even after the steam oxidation test for a short time. It was found that the precipitated S operated more effectively to the improvement of the steam oxidation resistance compared to the solid-solution state of S in the steels. Furthermore, the sulfur effect on the high temperature steam oxidation resistance was related strongly to the amount of dissolution hydrogen in the high Cr ferritic steels.

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