Material Performance in Supercritical Water

Corrosion Behaviour of Alloy 800H in Low Density Superheated Steam

“…26) Another study found oxide formed in 500°C SCW consisted of magnetite/spinel adjacent to the substrate and an external layer of hematite (Fe 2 O 3 ). 34) At higher SCW temperature of 600°C, magnetite outer oxide layer and spinel (Ni,Mn,Fe,Cr) 3 O 4 inner oxide layer were found after 1 000 hours. 35) Other study found an inner oxide layer of FeCrO 3 and outer layer of NiFe 2 O 4 after 1 440 hours in SCW at 600°C.…”

“…However, despite their superiority in oxidation and corrosion resistance Ni-based alloys have high neutron absorption cross sections and greater vulnerability to radiation damage than iron-based alloys, eliminating them as a candidate material for the reactor core. 10,15) Fe-based alloys containing Ni, particularly austenitic stainless steels, are of great interest for use in the Gen IV SCWRs because of their high resistance against creep and radiation as well as improved corrosion resistance over F-M steels. 16) Austenitic stainless steels are an attractive choice for in-core and out-of-core components as they are able to maintain their oxidation resistance and mechanical properties up to a temperature of 1 000°C in an oxidizing environment.…”

“…10,11) In an effort to improve upon F-M steels, the development of iron-based oxide dispersion strengthened (ODS) steels is being explored to improve the creep and tensile properties of the material at higher temperatures. 12) Ni-based alloys are another candidate for use in the SCWRs due to their ability to maintain high strength and toughness at elevated temperatures.…”

Corrosion Assessment of Candidate Materials for Fuel Cladding in Canadian SCWR

“…1,2 The SCWR is a hightemperature and high-pressure WCR in which the primary coolant is operated above the critical point of water (374°C, 22.1 MPa) in a direct once-through cycle that enables the elimination of components such as steam generators and steam separators and dryers. The idea of using supercritical water (SCW) as a reactor coolant was proposed in the 1960s because of noticeable advantages, such as high thermal efficiency, main system simplification, and low energy production cost.…”

Materials Science & Technology: Research and Challenges in Nuclear Fission Power

“…The major challenge for materials in the SCW environment is the resistance to SCC and irradiation-assisted SCC. Austenitic stainless steels and nickel based alloys suffered IGSCC in deaerated SCW at 400°C (Allen et al, 2012) and ferritic-martensitic steels showed SCC resistance in the same temperature range (Ampornrat et al, 2009). Austenitic stainless steels exhibited extreme embrittlement under neutron irradiation of 40 dpa in SCW; however, ferriticmartensitic steels showed good resistance (Teysseyre et al, 2007).…”