Corrosion of P235GH carbon steel in simulated Bure soil solution

In this study,the corrosion of carbon steel in the presence of callovo-oxfordian (cox) claystone/groundwater,wasinvestigated. to more closely emulate the storage conditions,the corrosion tests were systematically conducted under controlled atmosphere of 5% h2/n2,at different temperatures (three months at 30°c followed by three months at 90° c with cox claystone and synthetic groundwater. the corrosion products formed on the steel surface have been studied by scanning electron microscope/energy dispersive x-ray spectroscopy and confocal micro-raman measurements. chemical analyseshave been performed by inductively coupled plasma with mass spectrometry and ionic chromatography. at 30°c,the iron release in solution allowed the appearance of magnetite phase followed by the transformation of magnetite into mackinawite. however,the pyrite phase was formed when the temperature of 90 ° c was reached. the appearance of pyrite in the corrosion system at 90°c testifies in most cases that the transition phase from mackinawite to pyrite was influenced by both temperature and the excess of sulphide ions produced by sulphate-reducing-bacteria metabolism.