The corrosion behaviour of zinc–aluminium–magnesium-coated steel in a simulated polluted marine atmospheric environment was investigated.Therefore,an indoor ageing acceleration test was carefully designed by simulat...The corrosion behaviour of zinc–aluminium–magnesium-coated steel in a simulated polluted marine atmospheric environment was investigated.Therefore,an indoor ageing acceleration test was carefully designed by simulating a polluted marine environment.The objective was to in-depth investigate the corrosion mechanism of Zn–Al–Mg-coated steel exposed to a simulated polluted marine environment.The experiments were carried out by scanning electron microscopy for micro-morphological characterization,X-ray diffraction,electrochemical impedance spectroscopy and electrodynamic polarization curves for the aged samples.The analysis of the results obtained after an indoor accelerated ageing test shows that Zn–Al–Mg coatings generate insoluble Zn_(5)Cl_(2)(OH)_(8)·H_(2)O and Zn_(4)SO_(4)(OH)_(6)during the corrosion process,which hinders the diffusion of corrosive substances into the substrate,and the insoluble substances are structurally dense and thus inhibit further corrosion.Therefore,this effectively inhibits the occurrence of further corrosion,and thus,Zn–Al–Mg coating can significantly extend the service life of Zn–Al–Mg-coated steel.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2017YFB0304602)the National Natural Science Foundation of China(Nos.51771029)the National Environmental Corrosion Platform(NECP,2005DKA10400).
文摘The corrosion behaviour of zinc–aluminium–magnesium-coated steel in a simulated polluted marine atmospheric environment was investigated.Therefore,an indoor ageing acceleration test was carefully designed by simulating a polluted marine environment.The objective was to in-depth investigate the corrosion mechanism of Zn–Al–Mg-coated steel exposed to a simulated polluted marine environment.The experiments were carried out by scanning electron microscopy for micro-morphological characterization,X-ray diffraction,electrochemical impedance spectroscopy and electrodynamic polarization curves for the aged samples.The analysis of the results obtained after an indoor accelerated ageing test shows that Zn–Al–Mg coatings generate insoluble Zn_(5)Cl_(2)(OH)_(8)·H_(2)O and Zn_(4)SO_(4)(OH)_(6)during the corrosion process,which hinders the diffusion of corrosive substances into the substrate,and the insoluble substances are structurally dense and thus inhibit further corrosion.Therefore,this effectively inhibits the occurrence of further corrosion,and thus,Zn–Al–Mg coating can significantly extend the service life of Zn–Al–Mg-coated steel.
