Supercritical water, corrosion resistance

Reaction vessels for supercritical water oxidation must be highly corrosion resistant because of the aggressive nature of supercritical water and oxidation reaction products at extreme temperatures and pressures. Supercritical oxidation of PCBs and some chlorinated hydrocarbons can be difficult... 

R.J. Morin, Ceramics for Corrosion Resistance in Supercritical Water Environments, Thesis, University of Texas USA, (1993). 

It should be made of an inert, corrosion-resistant material such as Hastelloy-C or Inconel 702 if it is to hold supercritical water — supercritical CO, can be processed in stainless steel ... 

Hazelbeck, D.A. et al. (1995) Design of corrosion resistant HTO systems for DOD hazardous wastes. First International Workshop on Supercritical Water Oxidation, DOE, Amelia Island. 

Supercritical steam plants operating above the water critical temperature (375°C) and pressure (22 MPa) have the same mechanical components as conventional steam plants. Major differences are greater wall thicknesses to withstand the pressure, more corrosion resistant materials, and lower dissolved solids in the water and steam. 

S. Mahboubi, Effect of Cr Content on Corrosion Resistance of Fe-cr-ni Alloys Exposed in Supercritical Water (SCW) (MASc. thesis). Department of Materials Science and Engineering, McMaster University, September 2014. 

Y. Jiao, J. Kish, W. Cook, W. Zheng, D.A. Guzonas, Influence of thermal aging on the corrosion resistance of austenitic Fe-Cr-Ni alloys in SCW, in 6th International Symposium on Supercritical Water-Cooled Reactors (Shenzhen, Guangdong, China), March 03-07, 2013. 

The selection of materials for use in many industrial environments, including supercritical thermal power plants (SCTPPs) and Supercritical Water Oxidation (SCWO) systems requires a broad study of the forms and the rates of corrosion of various metals and alloys in supercritical (T > 374°C) aqueous environments. Nickel is an important component of many corrosion resistant alloys and is a classic model for corrosion studies. Extensive electrochemical polarization studies of this metal in... 

Material and structural issues to be addressed are primarily related to the potential for corrosion and stress corrosion cracking under irradiation at the high temperatures and pressures associated with the SCWR. Materials for cladding and structural components must be identified and tested to demonstrate their performance in thermal and fast-spectrum reactors. Radiolysis and water chemistry at supercritical conditions must be investigated to understand the effect on reactor materials. Specific material properties to be investigated include dimensional and microstructure stability, and strength, embrittlement, and creep resistance characteristics of the materials. 

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