Electrode

Intergranular corrosion

Pure mathematics

Tempering

Electron backscatter diffraction

Mathematics

Physical chemistry

Composite material

Aqueous solution

Chemistry

Metallurgy

Materials science

Immersion (mathematics)

Corrosion

Layer (electronics)

Grain boundary

Passivation

Electrochemistry

Microstructure

International Journal of Minerals Metallurgy and Materials

The corrosion behavior of 5wt%Cr steel tempered at different temperatures was investigated by immersion testing and electrochemical testing in a CO2 aqueous environment. When the tempering temperature exceeded 500°C, the corrosion rate increased. The corrosion layers consisted of Cr-rich compounds, which affected the corrosion behaviors of the steels immersed in the corrosive solution. The results of electrochemical experiments demonstrated that 5wt%Cr steels with different microstructures exhibited pre-passivation characteristics that decreased their corrosion rate. Analysis by electron back-scattered diffraction showed that the frequency of high-angle grain boundaries (HAGBs) and the corrosion rate were well-correlated in specimens tempered at different temperatures. The corrosion rate increased with increasing HAGB frequency.

Effect of the frequency of high-angle grain boundaries on the corrosion performance of 5wt%Cr steel in a CO2 aqueous environment