通过表面机械研磨技术 (SMAT) ,在纯铁和 38CrMoAl钢样品表面产生大量的塑性应变 ,致使其表层晶粒细化至纳米量级 .随后的气体渗氮实验表明 ,纳米纯铁和 38CrMoAl钢发生渗氮反应的温度大大低于传统粗晶材料 ( >5 0 0℃ ) ,分别降至约 30 0℃和 40 0℃ .这种低温渗氮过程不仅有利于降低渗氮工件的变形和能耗 ,也为选择性渗氮技术的实现提供了新途径 . A large amount of plastic strain was produced on the surface of pure iron and 38CrMoAl steel by surface mechanical milling (SMAT), resulting in grain refinement of the surface layer to the nanometer scale.The subsequent gas nitriding experiments showed that the nanosized pure iron and 38CrMoAl steel occurred The nitriding reaction temperature is much lower than that of the conventional coarse-grained material (> 500 ℃), which drops to about 300 ℃ and 400 ℃, respectively. This low-temperature nitriding process not only helps to reduce the deformation and energy consumption of the nitriding workpiece , But also for the realization of selective nitriding technology provides a new way.