Abstract
The effect of ferrite-pearlite and ferrite-martensite phase combinations on the passive layer properties of low carbon steel is investigated in a 0.1 M NaOH solution. Heat treatments were designed to obtain ferrite-pearlite and ferrite-martensite microstructures with similar ferrite volume fractions. Potentiostatic polarisation and electrochemical impedance spectroscopy (EIS) results demonstrated the lower barrier properties of passive films on ferrite-martensite microstructure compared to the ones formed on ferrite-pearlite microstructure. This was attributed to the higher donor density of the passive layer on ferrite-martensite samples, measured with Mott–Schottky analysis. This behaviour was explained by the complex microstructure morphology of the martensite phase that led to the formation of a more defective passive film
Original language | English |
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Article number | 594 |
Number of pages | 11 |
Journal | Metals |
Volume | 11 |
Issue number | 4 |
DOIs | |
Publication status | Published - 2021 |
Keywords
- HSLA steel
- dual-phase
- passivity
- EIS
- polarisation
- Mott–Schottky