热处理对FeCrMnNiCox合金微观组织及力学性能的影响

Effect of heat treatment on microstructure and mechanical properties of FeCrMnNiCox alloy

金属粉体经行星式球磨机混合后,采用真空熔铸技术制备FeCrMnNiCo,FeCrMnNiCo0.5,FeCrMnNi 3种多主元合金。采用金相显微镜、扫描电镜(SEM)、硬度计、万能拉伸试验机,研究热处理温度对3种多主元合金微观组织、拉伸性能和硬度的影响。结果表明:900℃热处理后的FeCrMnNi合金硬度最大为380HV;经过700℃热处理后FeCrMnNiCo0.5塑性最大,其断后伸长率为54.7%。同一热处理温度下,随着Co含量增多,组织从树枝状转变成蜂窝状,抗拉强度减小。同一种合金硬度随着热处理温度升高呈现增大的趋势,这可能与热处理后析出相增多有关,但其抗拉强度基本不变。

FeCrMnNiCo,FeCrMnNiCo0.5 and FeCrMnNi alloys were prepared by vacuum melting and casting technology after metal powders was mixed by planetary ball mill.The effects of heat treatment temperature on the microstructures,tensile properties and hardness of three kinds of multi-principal alloys were studied by means of metallographic microscope,scanning electron microscopy(SEM),hardness tester and universal tensile testing machine.The results show that the hardness of FeCrMnNi alloy after heat treatment at 900℃is the highest and the maximum hardness is 380 HV.The plasticity of FeCrMnNiCo0.5 alloy is the largest after heat treatment at 700℃,and its elongation after fracture is 54.7%.At the same heat treatment temperature,with the increase of Co content,the alloys’structure is changed from dendritic to honeycomb,and the alloys’tensile strength is decreased.The hardness of the same alloy is increased with the increase of heat treatment temperature,which may be related to the increase of precipitates after heat treatment,but its tensile strength remains unchanged.