The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic conditions.The results show that th...The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic conditions.The results show that the corrosion rates,corrosion morphologies and the composition of the corrosion products are strongly infl uenced by the molar deposition rate ratio of NaCl and SO2(NaCl/SO2).The corrosivity of NaCl and SO2 toward zinc increases in order of SO2<1:3<3:1<NaCl<1:1.The corrosion morphology is patchy corrosion for Group 1:1,while it is pocking corrosion for the other four experimental groups.The corrosion product containing sulfur and chlorine detected on zinc is Gordaite(NaZn4SO4(OH)6Cl·6H2O),which has quite porous structure and was supposed to cause the patchy corrosion tendency of zinc in Group 1:1.In addition,soluble zinc corrosion products,which can inhibit the atmospheric corrosion process of zinc,were found on zinc samples in Groups 1:3 and SO2 and connected to the lower corrosion rates of zinc in these two groups.展开更多
In order to better understand why the corrosion behavior of carbon steel exposed in Nansha atmospheric environment is very serious, the effect of sodium, potassium and magnesium chlorides deposited on carbon steel sur...In order to better understand why the corrosion behavior of carbon steel exposed in Nansha atmospheric environment is very serious, the effect of sodium, potassium and magnesium chlorides deposited on carbon steel surface has been studied under atmosphere conditions by wet/dry accelerated test. The difference of corrosion behavior and surface structure in Na+, K+, and Mg2+ containing atmosphere has been investigated by thickness loss, scanning electron microscope, X-ray diffraction and electrochemical techniques. The results indicate that the thickness loss of carbon steel exposed in different metal cations containing atmospheric environment increases in the order of Na+, K+, Mg2+. The hard metal cation can promote the dissolution of the steel to a certain extent. In Mg2+ containing atmosphere, the relative content of β-FeOOH is rather higher and the protective ability index α */γ * decreases in the order of Na+, K+, Mg2+. The corrosion current density of both bare carbon steel and the rusted carbon steel increases in the order of Na+, K+, Mg2+. The polarization resistance and the charge transfer resistance decreases in the order of Na+, K+, Mg2+.展开更多
The effect of simulated acidified marine aerosols on the corrosion morphology of carbon steel was studied using an in situ optical stereomicroscope and scanning electron microscope equipped with an energy-dispersive s...The effect of simulated acidified marine aerosols on the corrosion morphology of carbon steel was studied using an in situ optical stereomicroscope and scanning electron microscope equipped with an energy-dispersive spectrometer and a whitelight interferometer.The morphologies of the carbon steel were identified under marine aerosols with diiferent droplet diameters,pH,and acidifications.The results showed that corrosion was initiated in tens of seconds under aerosol droplets acidified by HCl or H2SO4.Despite the differences in the acidifier and diameter,corrosion for acidified droplets with pH>2 was general corrosion.For acidified droplets with pH<1,the corrosion morphology depended on the acidifier species,the ring-like morphology for HCl and ridge-like morphology for H2SO4.The segregation of Cl^-was believed to be the main factor for the formation of the corrosion morphology under acidified droplets with pH<1.Also,the concentration of SO4^2-in the droplets had some effect on the segregation of Cl-ions when pH<1.展开更多
基金supported by the National Science Fund of China under the Contract Nos. 51671197 and 51601199by Guangzhou Industry-university-research Collaborative Innovation Alliance Special Project under the Contract No. 201604046014
文摘The synergistic eff ect of NaCl and SO2 on the atmospheric corrosion of zinc has been studied at equivalent total but different ratios of molar deposition rate under wet–dry cyclic conditions.The results show that the corrosion rates,corrosion morphologies and the composition of the corrosion products are strongly infl uenced by the molar deposition rate ratio of NaCl and SO2(NaCl/SO2).The corrosivity of NaCl and SO2 toward zinc increases in order of SO2<1:3<3:1<NaCl<1:1.The corrosion morphology is patchy corrosion for Group 1:1,while it is pocking corrosion for the other four experimental groups.The corrosion product containing sulfur and chlorine detected on zinc is Gordaite(NaZn4SO4(OH)6Cl·6H2O),which has quite porous structure and was supposed to cause the patchy corrosion tendency of zinc in Group 1:1.In addition,soluble zinc corrosion products,which can inhibit the atmospheric corrosion process of zinc,were found on zinc samples in Groups 1:3 and SO2 and connected to the lower corrosion rates of zinc in these two groups.
基金the National Natural Science Foundation of China(No.51671197)the Strategic Priority Research Program of the Chinese Academy of Sciences XDA(No.13040502)。
文摘In order to better understand why the corrosion behavior of carbon steel exposed in Nansha atmospheric environment is very serious, the effect of sodium, potassium and magnesium chlorides deposited on carbon steel surface has been studied under atmosphere conditions by wet/dry accelerated test. The difference of corrosion behavior and surface structure in Na+, K+, and Mg2+ containing atmosphere has been investigated by thickness loss, scanning electron microscope, X-ray diffraction and electrochemical techniques. The results indicate that the thickness loss of carbon steel exposed in different metal cations containing atmospheric environment increases in the order of Na+, K+, Mg2+. The hard metal cation can promote the dissolution of the steel to a certain extent. In Mg2+ containing atmosphere, the relative content of β-FeOOH is rather higher and the protective ability index α */γ * decreases in the order of Na+, K+, Mg2+. The corrosion current density of both bare carbon steel and the rusted carbon steel increases in the order of Na+, K+, Mg2+. The polarization resistance and the charge transfer resistance decreases in the order of Na+, K+, Mg2+.
基金supported financially by the National Natural Science Foundation of China (Nos.51671197 and 51601199)the Guangzhou Industry-University-Research Collaborative Innovation Alliance Special Project (No.201604046014)
文摘The effect of simulated acidified marine aerosols on the corrosion morphology of carbon steel was studied using an in situ optical stereomicroscope and scanning electron microscope equipped with an energy-dispersive spectrometer and a whitelight interferometer.The morphologies of the carbon steel were identified under marine aerosols with diiferent droplet diameters,pH,and acidifications.The results showed that corrosion was initiated in tens of seconds under aerosol droplets acidified by HCl or H2SO4.Despite the differences in the acidifier and diameter,corrosion for acidified droplets with pH>2 was general corrosion.For acidified droplets with pH<1,the corrosion morphology depended on the acidifier species,the ring-like morphology for HCl and ridge-like morphology for H2SO4.The segregation of Cl^-was believed to be the main factor for the formation of the corrosion morphology under acidified droplets with pH<1.Also,the concentration of SO4^2-in the droplets had some effect on the segregation of Cl-ions when pH<1.
