Grooving corrosion of electric-resistance-welded oil well casing of J55 steel

Constant potential polarization approach was used to investigate the grooving corrosion performance of electric resistance welded oil well casings of J55 steels with different carbon content. The grooving corrosion sensitivity coefficient, α, depends intensively on the carbon content, microstructure of the steels and post-weld heat treatment. The steel with higher carbon content and fibrous pearlitic microstructure has higher grooving corrosion susceptibility. Post-weld heat treatment is shown to decrease the α value to some extent. The test solution and temperature have no apparent effects on the grooving corrosion sensitivity coefficient. The reasons for the grooving corrosion are discussed from the microstructure.

► New insights on the relationship between grooving corrosion and C-content of steels. ► A new finding of higher corrosion sensitivity in fibrous pearlitic microstructure. ► Effects of corrosive solution, temperature and post-weld heat treatment. ► A reason for the grooving corrosion from fibrous pearlitic microstructure.