Corrosion of carbon steel in clay compact environments at 90 °C: Effect of confined conditions

Abstract

Corrosion of low alloy carbon steel in simulated crevices and in a perforated envelope containing a rod, mimicking the liner-overpack system, was assessed at 90 °C in anoxic water-saturated clay. Corrosion in crevices was limited (< 1 μm/year). The corroded surface exposed magnetite with a fringe of siderite. Internal corrosion of the envelope was heterogeneous due to gradual filling with porewater, and average corrosion depth for the internal rod was limited to 11.5 μm after 76 months. Magnetite was the main corrosion product replacing steel, together with chukanovite, Fe silicate, and outer siderite in areas first bathed with porewater.