Cr_xCuFe_2Mo_(0.5)Nb_(0.5)Ni_2高熵合金的耐蚀性能

Corrosion Resistance of Cr_xCuFe_2Mo_(0.5)Nb_(0.5)Ni_2 High-entropy Alloys

采用真空电弧熔炼工艺制备了Cr_xCuFe_2Mo_(0.5)Nb_(0.5)Ni_2(x为Cr与Cu的摩尔比,分别为0、0.5、1.0、2.0)高熵合金,研究了合金在1mol/L H_2SO_4溶液中的耐腐蚀性能,并与S304不锈钢进行了比较。结果表明,合金中x=1.0或x=2.0时的腐蚀速率约为0.07mm/y,远低于x=0或x=0.5的合金及S304不锈钢,合金中x=0或x=0.5的腐蚀类型主要是沿晶腐蚀,而x=1.0或x=2.0的合金腐蚀类型主要是均匀腐蚀和点状腐蚀。x=0或x=0.5的合金中Cu、Nb、Mo的偏析程度较大,而x=1.0或x=2.0的合金中各元素分布相对均匀,因此原电池腐蚀程度相对较弱。极化腐蚀表明,x=2.0的合金具有最好的耐酸蚀性能,平均腐蚀速率仅为0.02mm/h,为S304不锈钢腐蚀速率的4%左右。

The CrxCuFe2Mo0.5Nb0.5Ni2（x=0,0.5,1.0,2.0）high entropy alloys were prepared by arc melting process.The corrosion resistance of these alloys and S304 stainless steel was analyzed by means of immersion and electrochemical polarization tests in 1 mol/L H2SO4 solution.The results show that the immersion corrosion rate of alloys with x=1.0and x=2.0is about 0.07mm/y and far below that of alloy with x=0and x=0.5and S304 alloys,which show that the alloys with x=1.0and x=2.0have a relatively descrable acid-resistance.The corrosion type of alloys with x=0and x=0.5exhibit mainly intergranular corrosion,while the corrosion surfaces of alloys with x=1.0and x=2.0are slight and the corrosion types are primarily uniform corrosion and pitting corrosion.The Cu,Nb,Mo elements in the alloys with x=0and x=0.5has a serious segregation,while the alloying elements are distributed homogeneously in the alloys with x=1.0and x=2.0.Therefore,the alloys with x=1.0and x=2.0have a better corrosion resistance than that of other alloys because of the slightly galvanic cell corrosion.Electrochemical polarization tests show that the alloy with x=2.0has the desirable acid-resistance among these alloys.The average corrosion rate of alloy with x=2.0is about 0.02mm/y,which is only about4% of the average corrosion of S304 stainless steel.