摘要
The carbon dioxide corrosion behavior of low alloy pipeline steel was investigated by immersion experiment. Optical microscopy （OM）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD） were used to reflect the microstructure of the tested material and the corrosion morphology characterization. Results show that precipitate particles may accelerate the iron cabonate crystal formation process of the nucleation growth and promote the formation of compact layer. The major corrosion phases are FeCO3 and complexity compound containing Fe and Cr. The corrosion behavior consists of three stages. At the first stage, a thin inner layer and an inhomogeneous outer layer have appeared. At the second stage, the outer layer becomes homogeneous and compact, which prevents corroding the steel substrate further. At the third stage, iron carbonate crystal tends to nucleate and grow locally. The corrosion rate obtained by weight loss method increases abruptly first and then decreases quickly with increasing corrosion time. The mutual relation among microstructure, corrosion surface morphology, corrosion phases and corrosion kinetics is discussed.
The carbon dioxide corrosion behavior of low alloy pipeline steel was investigated by immersion experiment. Optical microscopy （OM）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, and X-ray diffraction （XRD） were used to reflect the microstructure of the tested material and the corrosion morphology characterization. Results show that precipitate particles may accelerate the iron cabonate crystal formation process of the nucleation growth and promote the formation of compact layer. The major corrosion phases are FeCO3 and complexity compound containing Fe and Cr. The corrosion behavior consists of three stages. At the first stage, a thin inner layer and an inhomogeneous outer layer have appeared. At the second stage, the outer layer becomes homogeneous and compact, which prevents corroding the steel substrate further. At the third stage, iron carbonate crystal tends to nucleate and grow locally. The corrosion rate obtained by weight loss method increases abruptly first and then decreases quickly with increasing corrosion time. The mutual relation among microstructure, corrosion surface morphology, corrosion phases and corrosion kinetics is discussed.
基金
Supported by National Key Technology Research and Development Program of the Ministry of Science and Technology of China during the“12th Five-Year Plan”(No.2011BAE25B03)
National High Technology Research and Development Program of China(No.2015AA03A501)
the National Natural Science Foundation of China(No.51274063)
