Corrosion Studies of Candidate Materials for European HPLWR

The High Performance Light Water Reactor (HPLWR) design is one of the concepts chosen for Generation IV reactors; however, the material requirements for HPLWR offer challenges because of the extreme operating temperatures and pressures. Consequently, general corrosion rates were studied in water at 300 to 650 oC at supercritical pressure using weight gain measurements. Oxide thicknesses were determined from cross-section samples. The compositions of the oxide layers were analyzed using scanning electron microscopy in conjunction with energy dispersive spectroscopy. The surface layers of selected samples were analyzed also by X-ray diffraction. The test matrix included ten materials from four alloy classes: ferritic/martensitic steels, oxide dispersion strenghtened (ODS) steels, austenitic stainless steels, and nickel-base alloys. A high oxidation resistance was seen in Ni-base alloy 625, austenitic stainless steels with high Cr content and an ODS steel containing 20% Cr at all applied test temperatures. The oxidation rates of austenitic stainless stells with lower Cr content, 15 to 18%, increase considerably at temperatures > 500 oC. The oxidation rates of 9% Cr ODS steels were moderate or high at all temperatures. Ferritic/martensitic steels showed high oxidation rates at all temperatures.

PENTTILÄ Sami;  TOIVONEN Aki;  HEIKINHEIMO Liisa;  NOVOTNY Radek; 

2010-06-07

AMER NUCLEAR SOC

JRC58189

0029-5450,