Hydrogen permeation and corrosion behavior of high strength steel MCM 430 in cyclic wet–dry SO2 environment
2003; Elsevier BV; Volume: 46; Issue: 1 Linguagem: Inglês
10.1016/s0010-938x(03)00141-0
ISSN1879-0496
AutoresRokuro Nishimura, Daisuke Shiraishi, Yasuaki Maeda,
Tópico(s)Concrete Corrosion and Durability
ResumoHydrogen permeation caused by corrosion under a cyclic wet (2 h)–dry (10 h) SO2 condition was investigated for a high strength steel of MCM 430 by using an electrochemical technique in addition to the corrosion behavior obtained from weight loss measurement and the determination of corrosion products by using X-ray diffraction method. The hydrogen content converted from hydrogen permeation current density was observed in both wet and dry periods. The origin of proton was estimated to be from (1) the hydrolysis of ferrous ions, (2) the oxidation of ferrous ions and ferrous hydroxide, and (3) hydrolysis of SO2 and formation of FeSO4, but not from the dissociation of H2O. With respect to the determination of the corrosion products consisting of inner (adherent) and outer (not adherent) layers, the outer layer is composed of α-FeOOH, amorphous phase and γ-FeOOH, where α-FeOOH increases with the increase in the wet–dry cycle, and amorphous phase shows the reverse trend. The corrosion product in the inner layer is mainly Fe3O4 with them. On the basis of the results obtained, the role of the dry or wet period, the effect of SO2 and the corrosion process during the cyclic wet–dry periods were discussed.
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