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- 2010 (8) (entfernen)
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- Geothermie (2)
- Pitting corrosion (2)
- Self-corrosion (2)
- X-ray tomography (2)
- Carbon dioxide (1)
- Concrete (1)
- Concrete parameters (1)
- Contaminated mortar (1)
- CrNi-Stahl (1)
- Duplexstahl (1)
Eingeladener Vortrag
- nein (2)
Recent progress in the qualification of materials used in geothermal energy conversion systems
(2010)
Corrosion behavior of high-alloyed materials in an artificial geothermal fluid at service conditions
(2010)
Corrosion of steel reinforcement in concrete exposed to chloride containing environments is a serious problem in civil engineering practice. Electrochemical methods, e.g., potential mapping, provide information whether the steel reinforcement is still passive or depassivation has been initiated. By applying such techniques no information on the type of corrosion, its extent and distribution of corrosion products is available. Particular the corrosion progress is a significant problem. Especially in the case of macrocell corrosion in reinforced concrete structures, the development at the anode cannot be separated into corrosion damage resulting from macrocell corrosion or self-corrosion. Until now also in laboratory tests it is impossible to collect such information without destroying specimens after electrochemical testing was performed. To overcome this problem it was tried to study the steel surface within the mortar specimens by X-ray tomography (CT). Within the scope of these investigations it could be shown, that X-ray tomography is suitable to make corrosion pits and their development visible which are embedded in a mortar with a cover thickness of about 35 mm. In this publication the time-dependent corrosion damage of reinforced steel is documented by X-ray tomography.
The corrosion behaviour of martensitic stainless injection-pipeline steel X46Cr13 exposed to CO2 saturated artificial saline brine with high chloride concentration similar to onshore CCS-site at Ketzin, Germany has been investigated by means of electrochemical technique and microscopic observations at short exposure times (up to 24?h) and by mass loss and metallographic observations at exposure times up to 17520?h. Pitting corrosion kinetics has been characterised and the predictions about the corrosion mechanism are made.