Effect of normalization on ductility and corrosion resistance of API 5L-X65 PIPE

This research studies the effect of normalization on ductility and corrosion resistance of API 5L X65 pipe. Normalization conducted at a temperature of 900 °C with a holding time of 30, 60, 90, 120, and 150 minutes, followed by cooling down to a room temperature by using an external air. Corrosion testing of normalized specimens was performed using seawater as a corrosive environment, -and specimens were also tested for microhardness to determine their mechanical properties. Then, these test specimens were compared with specimens that did not undergo normalization in terms of their microstructure, hardness, and other mechanical properties. The specimens were analyzed by using an Energy Dispersive X-ray (EDX) Spectroscopy to determine the microstructure grain boundary, chemical composition and microcracking of the metal specimens. The results showed that the base metal hardness of API 5L X65 steel pipe fluctuated and tended to decrease. The highest hardness was obtained in specimens without normalizing, and the lowest in normalizing specimens. The highest corrosion rate occurred in specimens without normalizing, and the lowest in specimens with normalizing. Typical corrosion results of seawater on APL 5L-65 pipe are cracking and pitting