The process chain for Carbon Capture and Sequestration (CCS) includes tubing for injection of CO 2 into saline aquifers. The compressed CO 2 is likely to contain specific impurities; small concentrations of SO 2 and NO 2 in combination with oxygen and humidity are most harmful. In addition, CO 2 saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection has to ensure that neither CO 2 nor brine or a combination of both will leak out of the inner tubing. In this comprehensive paper the investigated materials range from low-alloy steels and 13% Cr steels up to high-alloy materials. Electrochemical tests as well as long term exposure tests were performed in CO 2 , in brine and combination of both; pressure was up to 100 bar, temperature up to 60 °C. Whereas the CO 2 stream itself can be handled using low alloy steels, combinations of CO 2 and brine require more resistant materials to control the strong tendency to pitting corrosion. The corrosion behavior of heat-treated steels depends on factors such as microstructure and carbon content. For different sections of the injection tube, appropriate materials should be used to guarantee safety and consider cost effectiveness.