Comparative evaluation of the oxidation resistance of untreated, annealed and quenched 434 ferritic stainless steels in corrosive electrolytes

Loto, R. T. (2022) Comparative evaluation of the oxidation resistance of untreated, annealed and quenched 434 ferritic stainless steels in corrosive electrolytes. Cogent Engineering, 9. ISSN 4: 1376488

PDF Download (5MB)

Abstract

The corrosion resilience of untreated, annealed and quenched 434 ferritic stainless steel (434FS) was studied in 1 M H2SO4 media at 0–1.75% NaCl concentration. Without the chlorides, annealed 434FS depicted the maximal corrosion rate output of 21.39 mm/y in comparison with 13.60 mm/y and 13.10 mm/y for the untreated and quenched 434FS. At 0.25% NaCl concentration, a significant decrease in the corrosion of untreated 434FS was observed (3.22 mm/y), which increased progressively with an increase in NaCl concentration till 15.44 mm/y (1.75% NaCl). Corrosion of annealed 434FS decreased to 15.37 (0.25% NaCl) and 8.44 mm/y (1.75% NaCl). Corrosion of quenched 434FS increased to 17.82 mm/y before decreasing to 8.93 mm/y at 1.75% NaCl concentration. The steels exhibited significant metastable pitting behaviour. However, the potential for metastable pitting activity decreased significantly for annealed and quenched 434FS. Annealed 434FS exhibited the widest passivation sweep outputs due to the durability of its passive film compared to untreated and quenched 434FS. An increase in NaCl concentration has a minor effect on the pittinbehaviour of the non-treated and 434 steels subjected to heat treatment. Optical images of annealed 434FS exhibited the highest resistance to localized deterioration with fewer corrosion pits compared to untreated and quenched 434FS in the presence of sulphates and chlorides. At the highest chloride concentration, the surface morphology of annealed 434FS showed superficial surface degradation compared to the severe surface degradation exhibited by the untreated and quenched 434FS.

Item Type:	Article
Uncontrolled Keywords:	steel; NaCl; pitting; corrosion; passivation; H2SO4
Subjects:	T Technology > T Technology (General) T Technology > TJ Mechanical engineering and machinery
Divisions:	Faculty of Engineering, Science and Mathematics > School of Engineering Sciences
Depositing User:	Mrs Hannah Akinwumi
Date Deposited:	03 Jun 2022 11:25
Last Modified:	03 Jun 2022 11:25
URI:	http://eprints.covenantuniversity.edu.ng/id/eprint/15936

Actions (login required)

View Item