热处理对CrFeNi2Nb0.45Sn0.05合金在显微演变和性能上的影响  

Effects of Heat Treatment on Microstructure Evolution and Properties of CrFeNi2Nb0.45Sn0.05 Alloys

作　　者：喻学谦 刘贵仲[1,2] Yu Xueqian;Liu Guizhong(Guilin University of Electronic Technology,Guilin 541004,China;Guangxi Key Laboratory of Information Materials,Guilin 541004,China)

机构地区：[1]桂林电子科技大学,广西桂林541004 [2]广西信息材料重点实验室,广西桂林541004

出　　处：《稀有金属》2019年第10期1109-1114,共6页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(511610065)资助

摘　　要：采用真空电弧熔炼炉制备CoCrFeNiNb0.45合金,再将样品分别在200, 600, 800和1000℃加热6 h,然后在冰水混合物中快速冷却。利用X射线衍射(XRD)、扫描电镜(SEM)、维氏硬度测量仪、万能试验机、电化学工作站以及X射线光电子能谱分析(XPS)研究了热处理对CrFeNi2Nb0.45Sn0.05合金在显微结构,机械性能和抗腐蚀能力上的影响。结果表明:合金由fcc相, bcc相以及Laves相构成,其中fcc相占据主导地位,并且随着淬火温度的升高,合金相的比例发生改变。在200℃之前,合金的Laves相受到抑制而减少,在600℃的时候, Laves相的比例大幅度提高,而经过1000℃淬火后,合金出现了σ沉淀相。同时该合金的硬度在经过600℃淬火能达到最大硬度HV 436.9,而其强度和塑性在经过200℃淬火也会超过铸态,达到最大值1790 MPa和32.5%。合金在1 mol·L^-1 NaCl溶液中有着卓越的抗腐蚀性,在其腐蚀期间,表面将形成了Nb2O5, Cr2O3和SnO 3种致密的氧化物来阻碍合金被进一步腐蚀。CoCrFeNiNb0.45 alloys were prepared by vacuum arc melting furnace, and then the samples were heated for 6 h at 200, 600, 800 and 1000 ℃ respectively and then cooled rapidly in a mixture of ice and water. The effect of heat treatment on microstructure, mechanical properties and corrosion resistance of CrFeNi2Nb0.45Sn0.05 alloys were studied by X-ray diffractometer(XRD), scanning electron microscope(SEM), Vickers hardness tester, Universal testing machine, electrochemical work station and X-ray photoelectron spectroscopy(XPS) analysis. The results showed that the alloy was composed of fcc phase, bcc phase and Laves phase, and the fcc phase occupied the leading position. The proportion of phases changed with the increase of quenching temperature. The Laves phase of the alloy was restrained and decreased before 200 ℃. At 600 ℃, the proportion of Laves phase increased greatly. After quenching at 1000 ℃, σ precipitation phase appeared in the alloy. After quenching at 600 ℃, the hardness of the alloy could reach the maximum hardness HV 436.9. The strength and plasticity of the alloy could exceed the as-cast after quenching at 200 ℃, reaching the maximum value of 1790 MPa and 32.5%. The alloy had excellent corrosion resistance in 1 mol·L^-1 NaCl solution. During the corrosion period, three dense oxides, Nb2O5, Cr2O3 and SnO, were formed on the surface of the alloy to prevent further corrosion.

关 键 词：显微结构 热处理 机械性能 抗腐蚀性 

分 类 号：TG113.1[金属学及工艺—物理冶金]