针对回填石和海淡水复杂介质环境中铝合金牺牲阳极对沉管隧道钢壳的长期保护效果,建立了1∶80物理缩比模型,采用加速电解方法模拟不同服役周期下的保护性能,并测试和分析了钢壳保护电位分布、介质电阻率变化及阳极溶解形貌。结果表明:...针对回填石和海淡水复杂介质环境中铝合金牺牲阳极对沉管隧道钢壳的长期保护效果,建立了1∶80物理缩比模型,采用加速电解方法模拟不同服役周期下的保护性能,并测试和分析了钢壳保护电位分布、介质电阻率变化及阳极溶解形貌。结果表明:初期钢壳保护电位在-1.0 V(vs.Ag/Ag Cl/海水电极,下同)以下,并随服役时间延长逐渐正移,末期平均保护电位为-0.91 V,但全周期(100 a)内始终满足电位低于-800 m V的阴极保护准则;随服役时间的延长,介质环境电阻率显著升高,由初期的66Ω·cm增至末期的146Ω·cm,牺牲阳极表现出稳定的电化学性能,末期电位仍保持负于-1.05 V,溶解形貌基本均匀,但因阳极尺寸缩减和介质电阻率升高,发生电流由40 m A降至11 m A。展开更多
In the process of protecting ferrous materials,aluminum coating usually forms a dense oxide film on the surface of the iron-based alloy.However,the capacity of the sacrificial anode is rather insufficient.In order to ...In the process of protecting ferrous materials,aluminum coating usually forms a dense oxide film on the surface of the iron-based alloy.However,the capacity of the sacrificial anode is rather insufficient.In order to solve this problem,the microstructure and electrochemical corrosion properties of Al-8Si-3Fe-xIn alloy under low chlorine conditions were studied.The results show that indium(In)dissolves to form In^(3+)and In^(+)reverse plating on the surface of the bare substrate to form a passivation film defect.When the In content is high,the segregated In forms an activation point in the form of a cathode phase.In activatesτ_(6)phase to form a micro-couple,which improves the non-uniform corrosion.The In-containing corrosion products at the phase boundary hinder the diffusion of Cl−.With an increase of In content,the self-corrosion potential(Ecorr)of the alloy shifts negatively,and the self-corrosion current density(Jcorr)decreases from 6.477μA/cm^(2)to 1.352μA/cm^(2),and then increases gradually.However,when the In content is 0.1%,the Ecorr of the alloy changes from−0.824 V to−0.932 V,and the Jcorr decreases from 6.477μA/cm^(2)to 4.699μA/cm^(2),suggesting that the use of sacrificial anode will give the best effect.展开更多
文摘针对回填石和海淡水复杂介质环境中铝合金牺牲阳极对沉管隧道钢壳的长期保护效果,建立了1∶80物理缩比模型,采用加速电解方法模拟不同服役周期下的保护性能,并测试和分析了钢壳保护电位分布、介质电阻率变化及阳极溶解形貌。结果表明:初期钢壳保护电位在-1.0 V(vs.Ag/Ag Cl/海水电极,下同)以下,并随服役时间延长逐渐正移,末期平均保护电位为-0.91 V,但全周期(100 a)内始终满足电位低于-800 m V的阴极保护准则;随服役时间的延长,介质环境电阻率显著升高,由初期的66Ω·cm增至末期的146Ω·cm,牺牲阳极表现出稳定的电化学性能,末期电位仍保持负于-1.05 V,溶解形貌基本均匀,但因阳极尺寸缩减和介质电阻率升高,发生电流由40 m A降至11 m A。
基金Projects(52171003,52271005)supported by the National Science and Technology Major Project of ChinaProject(KYCX23_3032)supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China。
文摘In the process of protecting ferrous materials,aluminum coating usually forms a dense oxide film on the surface of the iron-based alloy.However,the capacity of the sacrificial anode is rather insufficient.In order to solve this problem,the microstructure and electrochemical corrosion properties of Al-8Si-3Fe-xIn alloy under low chlorine conditions were studied.The results show that indium(In)dissolves to form In^(3+)and In^(+)reverse plating on the surface of the bare substrate to form a passivation film defect.When the In content is high,the segregated In forms an activation point in the form of a cathode phase.In activatesτ_(6)phase to form a micro-couple,which improves the non-uniform corrosion.The In-containing corrosion products at the phase boundary hinder the diffusion of Cl−.With an increase of In content,the self-corrosion potential(Ecorr)of the alloy shifts negatively,and the self-corrosion current density(Jcorr)decreases from 6.477μA/cm^(2)to 1.352μA/cm^(2),and then increases gradually.However,when the In content is 0.1%,the Ecorr of the alloy changes from−0.824 V to−0.932 V,and the Jcorr decreases from 6.477μA/cm^(2)to 4.699μA/cm^(2),suggesting that the use of sacrificial anode will give the best effect.
