Mechanical Properties and Corrosion Behavior of In-service 16Mn Steel for Dong-Huang Pipeline

The corrosion behavior of in-service 16Mn steel for Dong-Huang pipeline in Dongying simulated soil solution was investigated by open circuit potential test, polarization curves and electrochemical impedance spectroscopy. The mechanical properies of in-service 16 Mn steel were characterized as well. The results showed that the yield strength, ultimate tensile strength and Young’s modulus of in-service 16 Mn steel were reduced by comparing with those of 16 Mn steel before service. According to the electrochemical results, the corrosion process of in-service 16 Mn steel in Dongying simulated soil solution was characterized as general corrosion at the beginning, and localized corrosion occurred after several weeks of immersion. Moreover, there was no obvious mathematical relationship between corrosion rate and immersion time.