Investigation of Surface Nanocrystallization of 38CrSi Steel by SFPB
BA De-ma1, MA Shi-ning1, LI Chang-qing1, XIONG Tian-ying2
1. National Key Laboratory of Remanufacture Technology, Armored Force Engineering Institute, Beijing 100072, China; 2. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China
摘要采用超音速微粒轰击技术(Supersonic Fine Particles Bombarding,SFPB)对调质态合金钢38CrSi进行表面纳米化处理;利用X射线衍射、扫描电镜、透射电镜等分析技术研究不同工艺条件下表面纳米化层的微观组织结构特征.结果表明:经SFPB处理后,材料表层组织严重细化,并形成了纳米结构层(晶粒尺寸<100nm),随处理时间的延长,最表面纳米晶的尺寸变化不大,纳米结构层的厚度有所增加;当处理时间为240s时,在最表面层形成了平均晶粒尺寸约为16nm的具有随机取向的等轴纳米晶.纳米结构层的晶粒尺寸随着距表面距离的增加而增大.在距表面约25μm处,存在着大量的由位错线和高密度的位错缠结分割的胞块,尺寸为80~100nm;分析表明位错运动是表面纳米化的主要原因.
Abstract：A nanocrystalline surface layer was fabricated on a quenched and tempered 38CrSi steel by using Supersonic Fine Particles Bombarding(SFPB).The microstructural evolution of SFPB-treated specimens under different processing conditions was characterized by using X-ray diffraction,scanning electron microscopy,transmission electron microscopy.The results showed that obvious grains refinement was observed and a nanocrystalline surface layer(grain size<100nm) was found after SFPB treatment.The thickness of nanostructured surface layer increased depending upon the treatment duration,but the grain size of the top surface layer varied slightly.For the sample peened for 240s,the average size of equiaxed nanocrystallites with random crystallographic orientations on the top surface layer was approximately 16nm.The average grain size in the nanostructued layer increased with an increase of the distance from the top surface layer.In the region about 25μm depth from the top surface,large numbers of cell structures with size of 80-100nm separated by dense dislocation walls were formed.Experimental analysis indicated that grain refinement can be attributed to the movement of dislocation.
巴德玛, 马世宁, 李长青, 熊天英. 超音速微粒轰击38CrSi钢表面纳米化的研究[J]. 材料工程, 2006, 0(12): 3-7.
BA De-ma, MA Shi-ning, LI Chang-qing, XIONG Tian-ying. Investigation of Surface Nanocrystallization of 38CrSi Steel by SFPB. Journal of Materials Engineering, 2006, 0(12): 3-7.
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