Combined Thermo-Electric Power and Resistivity Measurements of Embrittlement Recovery in aged JRQ Ferritic Steel

Detection of microstructural changes caused by embrittlement and thermal treatments or history of the component, can be a very useful support to the safety and economy of the plant. Following previous studies on non-destructive assessment of neutron embrittlement of reactor pressure vessel steels, this paper presents results of relative Seebeck coefficient and resistivity obtained on thermally embrittled JRQ steel, a ferritic steel used as reference in many international projects. The Institute for Energy of the Joint Research Centre (JRC-IE) has developed two devices, focussed on the measurement of the electrical properties which prove to give a good non-destructive assessment of the embrittlement state of ferritic steels. The first technique, called STEAM (Seebeck and Thomson Effects on Aged Material), is based on the measurement of the relative Seebeck coefficient, characteristic of the material and related to the microstructural changes induced by embrittlement. With the same aim the second technique, named REAM (Resistivity Effects on Aged Material), measures instead the resistivity of the material. The applicability of combined measurements is also proposed. The results obtained prove that techniques based on the measurement of electrical properties can have interesting applications to non-destructive embrittlement assessment of ferritic steels.

SEVINI Filippo;  ACOSTA IBORRA Beatriz;  DEBARBERIS Luigi; 

2007-01-12

ELSEVIER SCI LTD

JRC30867