The present paper focuses on the corrosion of an austenitic (AISI304) and a duplex (2205) stainless steel grade in molten KOH/NaOH 50 w/o eutectic at 250 8C. Experimental activities have been performed consisting in electrochemical measurements (linear sweep voltammetry and electrochemical impedance spectrometry) complemented by metallographic (in-plane and cross-sectional SEM micrography), structural (X-ray diffractometry) and compositional (EDX line-profiles) characterisation of the materials attacked under electrochemically controlled conditions. Electrochemical measurements have shown that AISI304 exhibits a passivating behaviour, characterised by two passivation peaks and a transpassive threshold, while duplex, does not yield a clear indication of passivation. AISI304 was found to fail by intergranular corrosion and to be covered in both passive and transpassive conditions, by an incoherent scale, containing electrolyte species. Duplex samples, instead tends to fail by homogeneous attack and exhibit a range of scale structures, depending on the applied potential.

Corrosion of stainless steel grades in molten NaOH/KOH eutetic at 250 °C: AISI304 austenitic and 2205 duplex / B., Bozzini; S., Barella; F., Bogani; G., Giovannelli; Natali, Stefano; G., Scarselli; M., Boniardi. - In: MATERIALS AND CORROSION. - ISSN 0947-5117. - ELETTRONICO. - 63:11(2012), pp. 967-978. [10.1002/maco.201106386]

Corrosion of stainless steel grades in molten NaOH/KOH eutetic at 250 °C: AISI304 austenitic and 2205 duplex

NATALI, Stefano;
2012

Abstract

The present paper focuses on the corrosion of an austenitic (AISI304) and a duplex (2205) stainless steel grade in molten KOH/NaOH 50 w/o eutectic at 250 8C. Experimental activities have been performed consisting in electrochemical measurements (linear sweep voltammetry and electrochemical impedance spectrometry) complemented by metallographic (in-plane and cross-sectional SEM micrography), structural (X-ray diffractometry) and compositional (EDX line-profiles) characterisation of the materials attacked under electrochemically controlled conditions. Electrochemical measurements have shown that AISI304 exhibits a passivating behaviour, characterised by two passivation peaks and a transpassive threshold, while duplex, does not yield a clear indication of passivation. AISI304 was found to fail by intergranular corrosion and to be covered in both passive and transpassive conditions, by an incoherent scale, containing electrolyte species. Duplex samples, instead tends to fail by homogeneous attack and exhibit a range of scale structures, depending on the applied potential.
2012
corrosion; naoh/koh eutectic; stainless steels
01 Pubblicazione su rivista::01a Articolo in rivista
Corrosion of stainless steel grades in molten NaOH/KOH eutetic at 250 °C: AISI304 austenitic and 2205 duplex / B., Bozzini; S., Barella; F., Bogani; G., Giovannelli; Natali, Stefano; G., Scarselli; M., Boniardi. - In: MATERIALS AND CORROSION. - ISSN 0947-5117. - ELETTRONICO. - 63:11(2012), pp. 967-978. [10.1002/maco.201106386]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/501978
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