Brittle Fractures of Prestressed Bridge Steel Exposed to Chloride-Bearing Environments Caused by Corrosion-Generated Hydrogen

Abstract

Recent laboratory and field studies indicate many fractures of prestressed tendons in bridges exposed to deicing salt and to marine environments may be associated with embrittlement caused by cathodic hydrogen (H). This type of H originates from corrosion reactions inside occluded pits and results from the anodic oxidation of metallic iron (Fe) and the localized cathodic reduction of H ions. The primary factor influencing the hydrogen-induced cracking (HIC) is the concentration of H in the steel lattice, which is dependent on a variety of factors. Examination of these factors suggested cold-drawn pearlitic steels, which are used commonly to manufacture prestressed tendons, may be inherently susceptible to this type of failure. The danger of HIC would be reduced significantly if susceptibility could be evaluated using a routine quality control test with a clear-cut acceptance criterion. Although a variety of tests are used for this purpose, none has attained general recognition. The endurance axial test (based on the use of smooth specimens in ammonium thiocyanate (NH 4 CNS) and the fracture mechanics test (involving the use of precracked specimens exposed to simulated environments) appear promising.

Corrosion behavior of 17–4 PH stainless steel in simulated marine environment

“…It has been reported that aggressive anions of halides, especially chlorides, can cause the localized corrosion of 17–4 PH stainless steel . Novokshchenov propounded that the cracking tendency of pre‐stressed pearlitic steel increased with the increasing chloride concentrations. Therefore, the investigation on SCC behavior of martensitic steel under the combined effect of stress and corrosive medium is of great significance.…”

Effects of Hydrogen and Chloride Ions on Automobile Interstitial-Free Steel Corrosion

“…The Fe 2+ ions generated by the anodic reaction (Equation [1]) reacted with chloride ions that migrated to the anode to maintain charge neutrality, forming ferrous chloride (FeCl 2 ), [17][18][19] and reacted with OH -, which was generated by the cathodic reaction (Equation [2]), forming ferrous hydroxide (Fe[OH] 2 ). Hydrogen, existing in the atomic form in metal, diffuses from the charged electrode during the anodic oxidation, and is oxidized to a proton.…”

Electrochemical and fractographic analysis of Microbiologically Assisted Stress Corrosion Cracking of carbon steel

“…Moreover, hydrogen is playing a different but important role in MIC and SCC deteriora tion processes jeopardizing bath, the material integrity and the mechanical properties [10]. This is often associated with absorp tion of hydrogen in metal structures, which is known as hydrogen embrittlement [ 11 ]. The sec and MIC environments support corrosion reactions due to capability to produce hydrogen in various circumstances [10], for example, ferrous material being subject to tensile stress in an environment supporting the prolifer ation of hydrogen consuming Sulfate-Reducing Bacteria (SRB).…”