CuCrFeNiMn高熵合金在30%硝酸溶液中的耐蚀性能

Corrosion Resistance of CuCrFeNiMn High-Entropy Alloys in 30% HNO_3 Solution

目前针对高熵合金在硝酸溶液中的耐蚀性研究较少。采用真空电弧熔炼工艺制备了CuCrFeNiMn、CuCr_2Fe_2Ni_2Mn_2和Cu_2CrFe_2NiMn_23种高熵合金,采用浸蚀腐蚀方法研究了这3种合金在30%HNO_3溶液中的耐蚀性能,并与S304不锈钢进行了比较。结果表明:CuCrFeNiMn和Cu_2CrFe_2NiMn_2均由简单的面心立方固溶体(FCC1和FCC2)和体心立方固溶体(BCC)组成,而CuCr_2Fe_2Ni_2Mn_2合金则由单一面心立方固溶体相组成,3种高熵合金的微观组织呈典型的枝晶和枝晶间结构。浸蚀45 d后,CuCrFeNiMn,CuCr_2Fe_2Ni_2Mn_2,Cu_2CrFe_2NiMn_2和S304的平均腐蚀速率分别为0.273,0.087,2.369,3.502 mm/a,其中CuCr_2Fe_2Ni_2Mn_2合金的平均腐蚀速率约为S304不锈钢的1/40,表现出最佳的耐蚀性能;高熵合金的腐蚀类型主要为沿晶腐蚀。

Three kinds of high-entropy alloys( CuCrFeNiMn,CuCr2Fe2Ni2Mn2 and Cu2CrFe2NiMn2) was prepared by vacuum arc melting process. The corrosion resistance of these alloys was studied by means of immersion test in 30% HNO3 solution,which was compared with that of S304 stainless steel. Results showed that the CuCrFeNiMn and Cu2CrFe2NiMn2 alloys were composed of simple face centered cubic solid solution( FCC1 and FCC2) and body centerd cubic solid solution( BCC),while the CuCr2Fe2Ni2Mn2 alloy was made up with single face centered cubic solid solution. Additionally,the microstructure of these three alloys showed a typical dendrite and interdendrite structure. After45 days of immersion test,the average corrosion rates of CuCrFeNiMn,CuCr2Fe2Ni2Mn2,Cu2CrFe2NiMn2 and S304 stainless steel were 0.273mm/a,0.087 mm/a,2.369 mm/a and 3.502 mm/a,respectively. Among them,the average corrosion rate of CuCr2Fe2Ni2Mn2 alloy was about1/40 of that of S304 stainless steel,presenting the optimal corrosion resistance. Bedsides,the corrosion type of the alloys was dominated by intergranular corrosion.