In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion redu...In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.展开更多
In the present study,AlCoCrFeNi_(2.1)eutectic high-entropy alloy(EHEA)has been fabricated by laser melting deposition(LMD).The influence of laser energy density on microstructures,wear resistance and corrosion resista...In the present study,AlCoCrFeNi_(2.1)eutectic high-entropy alloy(EHEA)has been fabricated by laser melting deposition(LMD).The influence of laser energy density on microstructures,wear resistance and corrosion resistance of the alloy was systematically explored.The results indicate that the AlCoCrFeNi_(2.1)EHEA exhibited lamellar eutectic microstructures with alternating FCC and BCC phases.With the increase in laser energy density,the alloy grain size,interlamellar spacing,and volume fraction of the FCC phase increased,while the hardness of the alloy decreased.Meanwhile,the tribological performance of the alloy deteriorated with increasing laser energy density,and the combined effects of abrasive wear and adhesive wear gradually became significant.In addition,increasing laser energy density from 18.2 to 25 J/mm^(2)resulted in the increase in corrosion current density of the AlCoCrFeNi_(2.1)EHEA from 6.36×10^(−8) to 3.02×10^(−7) A/cm^(2)and the negative shift of corrosion potential from−211 to−292 mV(SCE).In summary,reducing laser energy density improved the wear and corrosion performance of the additively manufactured AlCoCrFeNi_(2.1)EHEA.展开更多
基金supported by the National Key Research and Development Program(No.2022YFC2806200)the National Key Research and Development Program(No.2023YFC2810800)the Natural Science Foundation of China(No.52001055).
文摘In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.
基金supported by the Jiangxi Provincial Key Research and Development Program(No.20232BBE50007)the Jiangxi Provincial Natural Science Foundation(No.20224BAB214018).
文摘In the present study,AlCoCrFeNi_(2.1)eutectic high-entropy alloy(EHEA)has been fabricated by laser melting deposition(LMD).The influence of laser energy density on microstructures,wear resistance and corrosion resistance of the alloy was systematically explored.The results indicate that the AlCoCrFeNi_(2.1)EHEA exhibited lamellar eutectic microstructures with alternating FCC and BCC phases.With the increase in laser energy density,the alloy grain size,interlamellar spacing,and volume fraction of the FCC phase increased,while the hardness of the alloy decreased.Meanwhile,the tribological performance of the alloy deteriorated with increasing laser energy density,and the combined effects of abrasive wear and adhesive wear gradually became significant.In addition,increasing laser energy density from 18.2 to 25 J/mm^(2)resulted in the increase in corrosion current density of the AlCoCrFeNi_(2.1)EHEA from 6.36×10^(−8) to 3.02×10^(−7) A/cm^(2)and the negative shift of corrosion potential from−211 to−292 mV(SCE).In summary,reducing laser energy density improved the wear and corrosion performance of the additively manufactured AlCoCrFeNi_(2.1)EHEA.
