Corrosion resistance of duplex stainless steels in selected organic acids and organic acid/chloride environments

Abstract

PurposeThe purpose of this paper is to supplement the scant previous investigations on the corrosion behaviour of 2205 and 2507 duplex stainless steels in selected organic acids containing chloride additions.Design/methodology/approachMicrostructural examination of the alloys was first carried out, after which the corrosion behaviour of the alloys in citric, oxalic, formic and acetic acids containing chloride additions at varying temperatures was studied using electrochemical techniques.FindingsThe alloy 2507 material had a larger grain size than did the alloy 2205 sample. The corrosion resistances of the alloys generally are highest in acetic acids and lowest in citric acid. The addition of chloride had a pronounced effect on their corrosion resistance. Alloy 2507 generally exhibited higher corrosion resistance in all of the acids than alloy 2205, with the exception of acetic acid at room temperature. The 50:50 ratio of ferrite to austenite composition, as revealed by phase compositional analysis, indicated no significant possibility for galvanic corrosion between the phases. This suggests that the corrosion behaviour of the alloys is controlled by their grain sizes and chemical compositions.Originality/valueAlthough the corrosion behaviour of duplex stainless steels in some organic acid media has been reported, this investigation covers the major organic acids not previously reported. Since in real industrial systems a mixture of both organic and minerals acids/salts may typically exist, investigations of the combined effect of chloride ions with the organic acids reported in this paper typify real industrial operations. The paper thus provides a basis for material selection for the application of 2205 and 2507 in industrial systems where organic acids are mostly used.

Microstructural Evolution Induced Mechanical Property Enhancement in Cryogenically Rolled Ce‐Modified SAF2507 Super Duplex Stainless Steel

“…The chromium‐rich ferrite, on the other hand, provides resistance to intergranular corrosion and stress corrosion in DSS. For instance, Adams et al [ 2 ] performed a detailed investigation on the corrosion behavior of 2205 and 2507 DSS in the presence of organic acid/chloride environments and temperature effects. In addition to a good corrosion resistance, the DSS with a lower nickel content owns a higher pitting resistance equivalent numbers (PREN) compared to the austenitic counterparts.…”

Heat Treatment of Duplex Stainless Steel 2205 by Inserting Nano Nd2FeB14 in HIP Manifolds Under the Scope of Category Theory

“…Also, we can reduce these spinodal reactions by grain refiners as they will be used to modify gibbs free energy for the total systems. By applying magnetic field and making magnetic bubbles, we can use their properties to control in the thermal charachteristics of the entire system (Alvarez-Armas & Degallaix-Moreuil, 2009;Adams, Olubambi, Potgieter, & Van Der Merwe, 2010;Kangas & Newman, 1998).…”

“…Horizontal bars correspond to the compositionrange of α and α′ phases measured by means of Mössbauer spectroscopy. These bars denote the miscibility gap boundary (Adams, Olubambi, Potgieter, & Van Der Merwe, 2010;Kim et al, 2005;Udarne & Nerjavnega, 2015;Maehara, Koike, Fujino, & Kunitake, 1983;Park & De Cooman, 2014;Frost & Ashby, 1982) Pattern formation processes due to phase separation of binary mixtures can conveniently be modelled by means of nonlocal Cahn-Hilliard equations. By this we mean H−1 gradient flows associated with functionals of GinzburgLandau type, which may include a dipolar interaction term.…”

Corrosion of an UNS S31803 distillation column for acetic acid recovery

“…Only few papers can be found in the literature dealing with the behavior of duplex stainless steels towards the corrosion in acetic acid [15][16][17][18][19].…”