The effect of dissolved oxygen on the oxidation of an austenitic steel in supercritical water

The oxidation of austenitic fine-grained steel TP347HFG exposed to supercritical water at 550 °C and 25 MPa with the dissolved oxygen concentration of 100 ppb, 300 ppb and 2000 ppb was investigated. The results indicated weight gain increased with the dissolved oxygen increasing. The herpes-shaped oxides were formed on the sample surface. The oxide layer was a typical dual-layered structure with a Fe-rich outer layer and a Fe-Cr-Ni-rich inner layer. The influences of the dissolved oxygen concentration and grain size on oxidation behavior were discussed finally.

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Effect of Thermal Pretreatment on the Corrosion of Stainless Steel in Flowing Supercritical Water

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4031125 ◽

2015 ◽

Vol 2 (1) ◽

Cited By ~ 1

Author(s):

Yinan Jiao ◽

Joseph R. Kish ◽

Graham Steeves ◽

William G. Cook ◽

Wenyue Zheng ◽

...

Keyword(s):

Stainless Steel ◽

Corrosion Resistance ◽

High Temperature ◽

Dissolved Oxygen ◽

Oxide Scale ◽

Supercritical Water ◽

Intermetallic Phase ◽

Compositional Variation ◽

Gravimetric Analysis ◽

Type 316L

The effect of high-temperature microstructure degradation (thermal ageing) on the corrosion resistance of austenitic stainless steels in supercritical water (SCW) was evaluated in this study. Mill-annealed (MA) and thermally treated (TT) samples of Type 316L and Type 310S stainless steel were exposed in 25 MPa SCW at 550°C with 8 ppm dissolved oxygen in a flowing autoclave testing loop. The thermal treatments applied to Type 316L (815°C for 1000 hr + water quench) and Type 310S (800°C for 1000 hr + air cool) were successful in precipitating the expected intermetallic phases in each alloy, both within the grains and on the grain boundaries. It was found that a prolonged time at relatively high temperature was sufficient to suppress significant compositional variation across the various intermetallic phase boundaries. This paper presents the results of the gravimetric analysis and oxide scale characterization using scanning electron microscopy (SEM) coupled with X-ray energy-dispersive spectroscopy (EDS). The role played by the fine precipitate structure on formation of the oxide scale, and thus corrosion resistance, is discussed. The combined role of dissolved oxygen and flow (revealed by examining the differences between Type 316L samples exposed in a static autoclave and in the flowing autoclave loop) is also addressed. It was concluded that formation of intermetallic phase precipitates during high-temperature exposure is not likely to have a major effect on the apparent corrosion resistance because of the discontinuous nature of the precipitation.

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The role of dissolved oxygen in supercritical water in the oxidation of ferritic–martensitic steel

The Journal of Supercritical Fluids ◽

10.1016/j.supflu.2015.10.017 ◽

2016 ◽

Vol 108 ◽

pp. 56-60 ◽

Cited By ~ 20

Author(s):

Zhongliang Zhu ◽

Hong Xu ◽

Dongfang Jiang ◽

Guoqiang Yue ◽

Baorang Li ◽

...

Keyword(s):

Dissolved Oxygen ◽

Supercritical Water ◽

Martensitic Steel

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Oxidation and chromia evaporation of austenitic steel TP347HFG in supercritical water

Materials at High Temperatures ◽

10.1080/09603409.2017.1381803 ◽

2017 ◽

Vol 35 (5) ◽

pp. 461-468 ◽

Cited By ~ 2

Author(s):

Naiqiang Zhang ◽

Qi Cao ◽

Jiajia Gui ◽

Mengyuan Li ◽

Yongzhong Ni ◽

...

Keyword(s):

Austenitic Steel ◽

Supercritical Water

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Corrosion Behavior of Modified UNS N08367 Austenitic Steel in Supercritical Water

CORROSION ◽

10.5006/1.3490311 ◽

2010 ◽

Vol 66 (9) ◽

pp. 096002-096002-5

Author(s):

Y. Yang ◽

Q. Yan ◽

R. Ma ◽

F. Zhu ◽

L. Zhang ◽

...

Keyword(s):

Austenitic Steel ◽

Corrosion Behavior ◽

Supercritical Water

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RESEARCH OF THE STATE OF INTERNAL SURFACES OF A SUPERCRITICAL WATER LOOP AFTER A SESSION OF IRRADIATION

10.46813/2020-127-180 ◽

2020 ◽

pp. 180-182

Author(s):

A.I. Azarov ◽

A.S. Bakai ◽

V.N. Boriskin ◽

V.A. Bocharov ◽

Yu.V. Gorenko ◽

...

Keyword(s):

Electron Beam ◽

Austenitic Steel ◽

Supercritical Water ◽

Active Oxygen ◽

The State ◽

Experimental Session ◽

Internal Surfaces ◽

Inner Surface ◽

The Impact

Made of austenitic steel at the NSC KIPT, the supercritical water convection loop Loop-1a was running for more than 500 hours in the first experimental session (in 2011). The materials tested in the loop were placed into a stream of water (more than 50 g/s) at a temperature of 350…400°C, a pressure of 23…25 MPa, and were irradiated by an electron beam with an energy of 10 MeV. Sediments that emerged on the inner surface of the loop were examined. The sediment mainly consisted of compounds of calcium and iron mixed with other elements. There is a possibility to increase corrosion induced by radiation due to dislocation damage, hydrogenation of metal and under the impact of active oxygen.

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