低成本Fe_(60)(CoCrNiMn)_(40)富铁中熵合金的显微组织与性能  

Microstructure and Properties of Low-Cost Iron-Rich Medium-Entropy Alloy Fe_(60)(CoCrNiMn)_(40)

作　　者：赵超杰 仝永刚 华熳煜[1] 吉希希 邓吨英 ZHAO Chaojie;TONG Yonggang;HUA Manyu;JI Xixi;DENG Dunying(School of Automotive and Mechanical Engineering,Changsha University of Science and Technology,Changsha 410114,China;School of Materials Science and Engineering,Changsha University of Science and Technology,Changsha 410114,China)

机构地区：[1]长沙理工大学汽车与机械工程学院,长沙410114 [2]长沙理工大学材料科学与工程学院,长沙410114

出　　处：《机械工程材料》2024年第1期53-59,共7页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(92166105,52005053);湖南省高新技术产业科技创新引导计划项目(2020GK2085);湖南省科技创新计划项目(2021RC3096)。

摘　　要：通过增加CoCrFeMnNi合金中的铁含量,制备了低成本富铁中熵合金Fe_(60)(CoCrNiMn)_(40)(原子分数/%),对其进行了1200℃×3 h均匀化处理、轧制和900℃×1 h退火处理,研究了该合金的显微组织、拉伸性能及耐腐蚀性能等。结果表明:试验合金由面心立方结构的单一奥氏体相组成,再结晶晶粒大小均匀,平均晶粒尺寸约为17.8μm,再结晶晶粒内出现退火孪晶;试验合金在室温下表现出优异的拉伸性能和应变硬化能力以及在NaCl溶液中显著的自钝化行为和优异的耐腐蚀性能,其抗拉强度为603 MPa,屈服强度为226 MPa,断后伸长率为81.6%,在NaCl溶液中的自腐蚀电位为-0.4616 V,自腐蚀电流密度为2.74×10^(-6) A·cm^(-2),电荷转移电阻为2.94×10^(5)Ω·cm^(2);与其他富铁多组分合金相比,试验合金的抗拉强度和断后伸长率更大,塑性应变高出10%以上,自腐蚀电流密度更低。试验合金的拉伸断口由均匀分布的韧窝组成,拉伸断裂方式为韧性断裂;在NaCl溶液中电化学腐蚀后,试验合金表面出现明显腐蚀坑,电化学腐蚀方式主要为点蚀。The low-cost iron rich medium-entropy alloy Fe_(60)(CoCrNiMn)_(40)(atom fraction/%)was prepared by increasing the iron content in the CoCrFeMnNi alloy,and then was treated by 1200℃×3 h homogenization,rolling and 900℃×1 h annealing.The microstructure,tensile properties,and corrosion resistance of the alloy were investigated.The results show that the test alloy was composed of a single austenitic phase with a face-centered cubic structure.The recrystallized grain size was uniform with the average value of about 17.8μm,and annealing twins appeared in the recrystallized grains.The test alloy showed good tensile properties and strain-hardening capacity at room temperature,as well as significant self-passivation behavior in NaCl solution and good corrosion resistance,with the tensile strength of 603 MPa,the yield strength of 226 MPa,the percentage elongation after fracture of 81.6%,the free-corrosion potential in the NaCl solution of 0.4616 V,the free-corrosion current density of 2.74×10^(-6)A·cm^(-2),and the charge transfer resistance of 2.94×10^(5)Ω·cm^(2).Compared with those of other iron-rich multicomponent alloys,the test alloy had higher tensile strength and percentage elongation after fracture,more than 10%higher plastic strain and lower free-corrosion current density.The tensile fracture of the test alloy consisted of uniformly distributed dimples,and the tensile fracture mode was toughness fracture.The obvious corrosion pits appeared on the test alloy surface after electrochemical corrosion in the NaCl solution,and the electrochemical corrosion mode was mainly pitting.

关 键 词：Fe_(60)(CoCrNiMn)_(40)中熵合金 面心立方结构 拉伸性能 耐腐蚀性能 

分 类 号：TB302.3[一般工业技术—材料科学与工程]