1. Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China 2. Pipeline Research Institute of CNPC, Langfang 065000, Hebei, China 3. School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
In-situ Corrosion Characterization of API X80 Steel and Its Corresponding HAZ Microstructures in an Acidic Environment
1. Corrosion and Protection Center, University of Science and Technology Beijing, Beijing 100083, China 2. Pipeline Research Institute of CNPC, Langfang 065000, Hebei, China 3. School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
ժҪ During heat treatment processing, microstructures of heat affected zone (HAZ) were formed in X80 pipeline steel. After observation by optical microscopy, scanning electron microscopy and transmission electron microscopy, microstructure of the as-received X80 steel was confirmed to be acicular ferrite, while the microstructures of quenched, normalized and annealed X80 steels were lath bainite, granular ferrite and quasi-polygonal ferrite, respectively. After immersion in the simulated acidic soil solution for 48 h, corrosion rates of these four steels were determined by mass loss measurements and corrosion products were examined by Raman spectroscopy and X-ray photoelectron spectroscopy. Scanning vibrating electrode technique was used to characterize the micro-galvanic corrosion behaviors of the synthetic bimetallic electrodes which were formed by coupling each of the simulated HAZ microstructures with the as-received steel in direct physical and electric contact. It is demonstrated that the as-received steel acts as cathode in the as-received/quenched and as-received/normalized couples, while the annealed steel acts as cathode when coupling with the as-received steel. The distinction of current density between the galvanic couples reduces with prolonging the immersion time.
Abstract��During heat treatment processing, microstructures of heat affected zone (HAZ) were formed in X80 pipeline steel. After observation by optical microscopy, scanning electron microscopy and transmission electron microscopy, microstructure of the as-received X80 steel was confirmed to be acicular ferrite, while the microstructures of quenched, normalized and annealed X80 steels were lath bainite, granular ferrite and quasi-polygonal ferrite, respectively. After immersion in the simulated acidic soil solution for 48 h, corrosion rates of these four steels were determined by mass loss measurements and corrosion products were examined by Raman spectroscopy and X-ray photoelectron spectroscopy. Scanning vibrating electrode technique was used to characterize the micro-galvanic corrosion behaviors of the synthetic bimetallic electrodes which were formed by coupling each of the simulated HAZ microstructures with the as-received steel in direct physical and electric contact. It is demonstrated that the as-received steel acts as cathode in the as-received/quenched and as-received/normalized couples, while the annealed steel acts as cathode when coupling with the as-received steel. The distinction of current density between the galvanic couples reduces with prolonging the immersion time.
��������:National Key Basic Research and Development Program of China;Science Fund for Distinguished Young Scholars of Hebei Province
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E-mail: ustbwangliwei@126.com
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Li-wei WANG,,Xiao-gang LI,Cui-wei DU,Peng ZHANG,Yi-zhong HUANG. In-situ Corrosion Characterization of API X80 Steel and Its Corresponding HAZ Microstructures in an Acidic Environment[J]. �й������ڿ���, 2015, 22(2): 135-144.
Li-wei WANG,,Xiao-gang LI,Cui-wei DU,Peng ZHANG,Yi-zhong HUANG. In-situ Corrosion Characterization of API X80 Steel and Its Corresponding HAZ Microstructures in an Acidic Environment. Chinese Journal of Iron and Steel, 2015, 22(2): 135-144.
2015, Vol. 22 
