用TEM对 6 40℃渗氮油淬 ,2 2 5℃等温 3 5h的工业纯铁进行分析 ,观察部位的含氮量 (w)约为 2 2 %～ 2 4%。在“未分解”的奥氏体选区衍射花样中γ′-Fe4N和γ -Fe已明显分离为两套独立的斑点 ,在 (2 0 0 ) γ′的暗场像中显示出在高氮奥氏体内析出高密度纳米级沉淀γ′,其平均尺寸约 10nm ,析出物之间的间距亦为纳米级。根据实验观察结果 ,提出用热处理方法制备大体积纳米材料的途径 The industrial pure iron with 6 40 ℃ nitriding oil quenching and 235 ℃ isothermal 35 h was analyzed by TEM, and the nitrogen content (w) of the observation site was about 22% ~ 24%. Γ’-Fe4N and γ-Fe have clearly separated into two independent sets of spots in the “undissociated” diffraction pattern of the austenitic constituency. The dark field images of (2000) γ ’ The precipitation of high-density nano-precipitated body γ ’, the average size of about 10nm, the spacing between the precipitates is also nanoscale. According to the experimental results, the way to prepare large volume nanomaterials by heat treatment is proposed