The fracture of pipelines caused by corrosion cracks and the resulting oil and gas leakage can lead to great environmentalpollution and economic losses. These negative effects are due to serious corrosion of the plain...The fracture of pipelines caused by corrosion cracks and the resulting oil and gas leakage can lead to great environmentalpollution and economic losses. These negative effects are due to serious corrosion of the plain carbon steels used for armorof flexible pipe in oil and gas transmission medium. However, corrosion resistance of carbon steel armors has yet to beimproved. In this study, the relationship between corrosion resistance and pearlite fraction in the plain carbon steels hasbeen investigated through the application of pulsed electric current. Based on immersion test and electrochemical mea-surement, pulsed electric current increases the corrosion resistance of the plain carbon steels by reducing the fraction ofpearlite phase. Pitting corrosion, which tends to initiate by galvanic corrosion of ferrite and cementite, is therefore inhibiteddue to the decrease in pearlite fraction （mixture of ferrite and cementite） under electropulsing.展开更多
Controlling the precipitation through thermomechanical treatment is an important method to improve the corrosion resistance of Al–Cu–Mg alloys. In this study, the corrosion behaviors of Al–Cu–Mg alloys in the solu...Controlling the precipitation through thermomechanical treatment is an important method to improve the corrosion resistance of Al–Cu–Mg alloys. In this study, the corrosion behaviors of Al–Cu–Mg alloys in the solution-treated state and retrogressiontreated state under cold rolling deformation and then natural aging were investigated. In the solution-treated series alloys, the cold-rolled deformation improved the resistance to intergranular corrosion by suppressing the precipitation of the S-phase on the grain boundaries. The increased pitting potential and corrosion potential were related to the increased concentration of solute atoms within the grain interiors and the eliminated S-phase on grain boundaries. In the retrogression-treated series alloys, the 30% cold rolling deformation stimulated the growth of the S-phase and transformed the S-phase distribution from discontinuous to continuous on the grain boundaries, thereby changing the pitting corrosion to the network corrosion morphology. The precipitation of the S-phase with large dimension within the grain interiors contributed to the decreased pitting potential and corrosion potential.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51601011)the Fundamental Research Funds for the Central Universities+2 种基金the Recruitment Program of Global Expertsthe State Grid Scientific and Technological Research Program of China(No.5211DS17001X)the Zhejiang Electric Power Corporation Scientific and Technological Research Program of China(No.5211DS5002 M).
文摘The fracture of pipelines caused by corrosion cracks and the resulting oil and gas leakage can lead to great environmentalpollution and economic losses. These negative effects are due to serious corrosion of the plain carbon steels used for armorof flexible pipe in oil and gas transmission medium. However, corrosion resistance of carbon steel armors has yet to beimproved. In this study, the relationship between corrosion resistance and pearlite fraction in the plain carbon steels hasbeen investigated through the application of pulsed electric current. Based on immersion test and electrochemical mea-surement, pulsed electric current increases the corrosion resistance of the plain carbon steels by reducing the fraction ofpearlite phase. Pitting corrosion, which tends to initiate by galvanic corrosion of ferrite and cementite, is therefore inhibiteddue to the decrease in pearlite fraction （mixture of ferrite and cementite） under electropulsing.
基金supported by the Science and Technology Innovation Major Project of Ningbo(No.2019B10101)the National Natural Science Foundation of China(Nos.U21B2082,U1860206,51601011,51874023)+1 种基金the Fundamental Research Funds for the Central Universities(No.FRF-TP-20-04B)the Recruitment Program of Global Experts,and the State Grid Scientifi c and Technological Research Program of China(No.5211DS17001X)。
文摘Controlling the precipitation through thermomechanical treatment is an important method to improve the corrosion resistance of Al–Cu–Mg alloys. In this study, the corrosion behaviors of Al–Cu–Mg alloys in the solution-treated state and retrogressiontreated state under cold rolling deformation and then natural aging were investigated. In the solution-treated series alloys, the cold-rolled deformation improved the resistance to intergranular corrosion by suppressing the precipitation of the S-phase on the grain boundaries. The increased pitting potential and corrosion potential were related to the increased concentration of solute atoms within the grain interiors and the eliminated S-phase on grain boundaries. In the retrogression-treated series alloys, the 30% cold rolling deformation stimulated the growth of the S-phase and transformed the S-phase distribution from discontinuous to continuous on the grain boundaries, thereby changing the pitting corrosion to the network corrosion morphology. The precipitation of the S-phase with large dimension within the grain interiors contributed to the decreased pitting potential and corrosion potential.
