A novel nanocrystallization technique of surface mechanical attrition treatment (SMAT) has been introduced for low temperature plasma nitriding of stainless steel. This research work was performed by a research group led by Prof. Xue Qunji from the CAS Lanzhou Institute of Chemical Physics in cooperation with Prof. Jian Lu of University of Technology of Troyes (Prof. Lu has since moved to Hong Kong Polytechnic University). The newest results of this research shows that the longstanding difficulty of the stainless steels nitriding may be solved by surface nano-structrued pre-treatment and the related research work was reported by Acta Materialia ("Surface nanocrystallization by surface mechanical attrition treatment and its effect on structure and properties of plasma nitrided AISI 321 stainless stee").