This study investigated the effect of Nb-content on the corrosion behavior of the Al_(7)Cr_(20)Fe_(35-x)Ni_(35)Mo_(3)Nb_(x)(x=0,1 and 2)high-entropy alloys in a Cl-environment.The results indicated that only the face ...This study investigated the effect of Nb-content on the corrosion behavior of the Al_(7)Cr_(20)Fe_(35-x)Ni_(35)Mo_(3)Nb_(x)(x=0,1 and 2)high-entropy alloys in a Cl-environment.The results indicated that only the face centered cubic phase existed in the NbO and Nbl alloys,while the emergence of Laves phase was observed when Nb-content reached 2 at.%.The NbO and Nb1alloys exhibited pitting corrosion,while the NiAl-rich phase experienced localized preferential corrosion in the Nb2 alloy.The electrochemical results revealed that the corrosion current density of the Nbx(x=0,1 and 2)alloys fell within the range of 10^(-8)-10-7 A·cm^(-2),with a pitting corrosion potential exceeding 700 mVSCE.Notably,the Nb1 alloy exhibited the most impressive corrosion resistance,as its corrosion current density(7×10^(-8)A·cm^(-2))was merely half that of 316LN stainless steel.This is attributed to its rapid passivation process,resulting in the development of a protective film characterized by an increased Cr_(2)O_(3)/Al_(2)O_(3)+Cr(OH)_(3)ratio.This study highlighted that the addition of Nb contributed to gram refinement,decreased corrosion current density,and elevated pitting potential,favoring passivation and improving corrosion resistance.However,excessive Nb-content resulted in the emergence of the Laves phase,inducing galvanic corrosion and diminishing resistance to corrosion.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(52001083,U2141207,52171111)Natural Science Foundation of Heilongjiang(YQ2023E026)。
文摘This study investigated the effect of Nb-content on the corrosion behavior of the Al_(7)Cr_(20)Fe_(35-x)Ni_(35)Mo_(3)Nb_(x)(x=0,1 and 2)high-entropy alloys in a Cl-environment.The results indicated that only the face centered cubic phase existed in the NbO and Nbl alloys,while the emergence of Laves phase was observed when Nb-content reached 2 at.%.The NbO and Nb1alloys exhibited pitting corrosion,while the NiAl-rich phase experienced localized preferential corrosion in the Nb2 alloy.The electrochemical results revealed that the corrosion current density of the Nbx(x=0,1 and 2)alloys fell within the range of 10^(-8)-10-7 A·cm^(-2),with a pitting corrosion potential exceeding 700 mVSCE.Notably,the Nb1 alloy exhibited the most impressive corrosion resistance,as its corrosion current density(7×10^(-8)A·cm^(-2))was merely half that of 316LN stainless steel.This is attributed to its rapid passivation process,resulting in the development of a protective film characterized by an increased Cr_(2)O_(3)/Al_(2)O_(3)+Cr(OH)_(3)ratio.This study highlighted that the addition of Nb contributed to gram refinement,decreased corrosion current density,and elevated pitting potential,favoring passivation and improving corrosion resistance.However,excessive Nb-content resulted in the emergence of the Laves phase,inducing galvanic corrosion and diminishing resistance to corrosion.
