Spatial distribution of crystalline corrosion products formed during corrosion of stainless steel in concrete

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Serdar M., Meral Ç., Kunz M., Bjegovic D., Wenk H., Monteiro P. J.

CEMENT AND CONCRETE RESEARCH, vol.71, pp.93-105, 2015 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 71
  • Publication Date: 2015
  • Doi Number: 10.1016/j.cemconres.2015.02.004
  • Journal Name: CEMENT AND CONCRETE RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.93-105
  • Keywords: Backscattered Electron Imaging, X-ray micro-diffraction, Corrosion, Concrete, Stainless steel, MULTIPHASE INTERFACE STRUCTURES, X-RAY MICRODIFFRACTION, ELECTROCHEMICAL PHENOMENA, ELECTRICAL-PROPERTIES, BEHAVIOR, ALKALINE, LAYER, MICROSTRUCTURE, CRACKING, REINFORCEMENT
  • Middle East Technical University Affiliated: Yes

Abstract

The mineralogy and spatial distribution of nano-crystalline corrosion products that form in the steel/concrete interface were characterized using synchrotron X-ray micro-diffraction (mu-XRD). Two types of low-nickel high-chromium reinforcing steels embedded into mortar and exposed to NaCl solution were investigated. Corrosion in the samples was confirmed by electrochemical impedance spectroscopy (EIS). mu-XRD revealed that goethite (alpha-FeOOH) and akaganeite (beta-FeOOH) are the main iron oxide-hydroxides formed during the chloride-induced corrosion of stainless steel in concrete. Goethite is formed closer to the surface of the steel due to the presence of chromium in the steel, while akaganeite is formed further away from the surface due to the presence of chloride ions. Detailed microstructural analysis is shown and discussed on one sample of each type of steel. (C) 2015 Elsevier Ltd. All rights reserved.