Acceleration of irradiation hardening of low-copper reactor pressure vessel steel observed by means of SANS and tensile testing
Acceleration of irradiation hardening of low-copper reactor pressure vessel steel observed by means of SANS and tensile testing
Bergner, F.; Ulbricht, A.; Viehrig, H.-W.
Neutron irradiation of low-copper reactor pressure vessel steels containing manganese and nickel gives rise to microstructural changes and a deterioration of mechanical properties apparently progressing slower than in steels containing more than or about 0.1 wt% Cu. An acceleration of this process after accumulation of a threshold fluence caused by so-called late blooming phases is a matter of debate. We report results of small angle neutron scattering (SANS) experiments and tensile tests for two low-Cu model RPV steels irradiated at 255°C. Motivation for the use of the integrated magnetic scattering as a microstructural parameter combining the volume fraction and magnetic contrast of nanometre-sized irradiation-induced features is given. The results indicate one of the rare cases of acceleration of both the change of a microstructural parameter and the yield stress increase. The issues of the nature of the irradiation-induced features, the role of phosphorus, and the observed strong correlation of integrated magnetic scattering and yield stress increase are addressed.
Keywords: neutron irradiation; SANS; tensile testing; pressure vessel steel
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Philosophical Magazine Letters 89(2009)12, 795-805
DOI: 10.1080/09500830903304117
Cited 34 times in Scopus
Permalink: https://www.hzdr.de/publications/Publ-12182