Effect of Mo and Cu on stress corrosion cracking of ferritic stainless steel in chloride media. (25th October 2015)

• Record Type: Journal Article
• Authors: Li, X.; Shu, J.; Chen, L.; Bi, H.
• Is Part Of: Corrosion engineering, science, and technology. Volume 50:Number 8(2015)
• Page Start: 618
• Page End: 627
• Publication Date: 2015-10-25
• Subjects: Stainless steel -- TEM -- XPS -- Inclusion -- Stress corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1179/1743278215Y.0000000014
• Languages: English
• ISSNs: 1478-422X

Abstract

Abstract : Stress corrosion cracking behaviour of ferritic stainless steels with copper and molybdenum additions in 42 wt-% boiling magnesium chloride at 143 ± 1°C has been determined. The nature of the corrosion products was analysed by X-ray photoelectron spectroscopy (XPS). XPS results show that the presence of Fe(0), Cr(0) and Mo(0) unoxidised states on the crack tips of (copper+molybdenum) addition ferritic stainless steel cannot form the stable passive film and causes the further corrosion in the chloride solution. The addition of both copper and molybdenum to 19% Cr ferritic stainless steel causes stress corrosion cracking. The susceptibility to stress corrosion cracking increases with the growth of ε-copper precipitates, and the fracture mode changes from transgranular to intergranular with the increasing aging time. Stress corrosion cracking initiates from pitting of ε-copper phases, then propagates to molybdenum atoms, and finally propagates to the other ε-copper precipitations perpendicular to the direction of maximum strain.