1996 Fiscal Year Final Research Report Summary
Not-and Gas-Corroison in Simulated Environments in Incineleter Boilers at High Tmeperatures
| Project/Area Number |
06453086
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
NARITA Toshio Hokkaido Univ., Fac.of Eng., Pro., 工学部, 教授 (60001252)
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| Project Period (FY) |
1994 – 1996
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| Keywords | boiler / high temperature corrosion / sulfidation / localized corrosion / grain boundary corrosion / chloridation / Fe-Cr alloy / Fe-Mn alloy |
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| Research Abstract |
Sulfidation behavior of Fe-26at%Cr, -36at%Cr, and -12at%Mn alloys at temperatures of 1073 and 1173K was investigated at a sulfur pressure lower than the dissociation pressure of ferrous sulfide at each temperature. External sulfide scale (Fe, Cr)_3S_4 and (Fe, Mn) S were formed with or without formation of an internal sulfide. The general internal sulfidation appeared for the Fe-Mn alloy at both tomperatures and for the Fe-26at%Cr alloy at 1173K.The former was due to the smaller diffusivity in the alloy and the latter was due to an alpha to gamma phase transformation. Sulfidation of the Fe-26at%Cr alloy at 1073K was confined within alloy grain boundaries. This was due to high sulfur solubility there. The mixture of general and grain boundary sulfidation apperared when the Fe-36at%Cr alloy was sulfidized at 1173K.
Deviation from stoichiometric composition of ferrous sulfide and solid solution (Fe, Cr)_<1-delta>S containing up to 0.3 mole cation fraction was measured as functions of sulfide composition and sulfur pressure and temperatures.
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