摘要
利用高真空感应炉熔炼制备高纯 (C +N <10 0× 10 -6)Fe - 14%Cr和Fe - 18%Cr合金。经区域提纯 (HFZ)后获得更高纯 (C +N +O <40× 10 -6)合金 .实验发现区域提纯去除C比去除N ,O ,S更难一些。在加热过程中 ,含碳量越少 ,晶粒开始长大温度越低。合金在 77～ 973K温度区间的拉伸实验结果表明 :纯度增加可以使室温下的塑性增加 ;在 473～ 82 3K温度范围内 ,所有高纯和超高纯样品均出现锯齿状流变 ,在 6 73K下尤为明显 .锯齿状流变的原因可认为是固溶N所产生的动态应变时效造成的 .Fe - 18%Cr合金中锯齿流变产生的名义活化能比低碳钢中的值大得多 ,表明Fe
High purity (C+N<×10 -6 ) Fe-14Cr% and Fe-18%Cr alloys were prepared using a high vacuum inducting melting furnace. These alloys were further refined by the HFZ (Floating Zone refining in a dry Hydrogen atmosphere) in order to obtain ultra high purity alloys (C+N+O <×10 -6 ). It was found that removal of C by the HFZ treatment is not so easy as that of N, O and S. Mechanical properties of these alloys at temperatures ranging from 77 to 973K were investigated. Increasing purity brought about improvement of ductility at ambient temperature. All of the high and ultra high purity Fe Cr alloys showed serrated flow between 473 and 823K, it being most profuse at 673K. The occurrence of serrated flow was considered as the result of dynamic strain aging caused primarily by nitrogen in solid solution. The nominal activation energy of the onset of serration was estimated as 116.5kJ/mol, which is larger than that reported in mild steel. It was presumed that diffusion of N in Fe-Cr alloys was suppressed by its interaction with Cr atoms.
出处
《黄金学报》
2001年第2期81-85,共5页
Gold Journal
基金
辽宁省博士启动基金 ( 96 10 5 4)
教育部留学回国人员基金的资助
