Corrosion properties of nickel free austenitic stainless steels in 0·5M H2SO4 and 0·5M H2SO4 plus 0·4M NaCl
Authors: Milititsky, M.1; Verhaege, M.2; de Wispelaere, N.3; Peguet, L.4; Ferreira, J.Z.5; Hänninen, H.6
Source: Corrosion Engineering, Science and Technology, Volume 44, Number 5, October 2009 , pp. 394-400(7)
Publisher: Maney Publishing
Abstract:
The corrosion behaviour of four nickel free austenitic stainless steels were investigated in 0·5M H2SO4 and 0·5M H2SO4 plus 0·4M NaCl solutions by means of potentiodynamic and potentiostatic anodic polarisation testing. The performances of the nickel free alloys are compared to those of an experimental intermediate nickel alloy (4%Ni) and a standard AISI 304 steel grade. Once passivity was reached all alloys displayed similar current densities ip in 0·5M H2SO4, independent from alloying. Mo and Cu were shown to be beneficial in decreasing the active dissolution currents and icrit values. The commercial AISI 304 steel displayed superior resistance to pit initiation during potentiodynamic testing, and AISI 304 steel displayed the highest Epit value of all alloys tested. When tested potentiostatically the N and Mo alloyed nickel free alloys showed excellent resistance to pit initiation and growth. The dominant effect of N was associated with repassivation of incipient pits, while Mo appeared to act at an earlier stage, suppressing initiation.Keywords: NICKEL FREE AUSTENITIC STAINLESS STEEL; GENERAL CORROSION; PITTING CORROSION
Document Type: Research article
DOI: 10.1179/174327808X326946
Affiliations: 1: Department of Metallurgy, Ghent University, Technologiepark 903 B-9052 Zwijnaarde (Ghent), Belgium;, Email: marcio.milititsky@ugent.be 2: Department of Metallurgy, Ghent University, Technologiepark 903 B-9052 Zwijnaarde (Ghent), Belgium 3: Arcelor Mittal Research Institute Ghent, OCAS, John Kennedylaan 3, B-9060 Zelzate, Belgium 4: UGINE-ALZ Research Centre (Arcelor/Mittal group), BP 15, 62330 Isbergues, France 5: Materials Department, Universidade Federal do Rio Grande do Sul, PPGEM, Av. Bento Gonçalves 9500, Setor 4, Prédio 74, 91501-970, Porto Alegre, Brazil 6: Laboratory of Engineering Materials, Helsinki University of Technology, Puumiehenkuja 3, FIN-02150, Espoo, Finland

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