Strain-induced formation of a gradient nanostructured surface layer on an ultrahigh strength bearing steel
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2018年第9期
论文作者：K.Zhang Z.B.Wang
文章页码：1676 - 1684
摘 要：In the present work, an ultrahigh strength bearing steel（AISI 52100） was subjected to surface mechanical rolling treatment（SMRT） at room temperature. Microstructural observations showed that martensitic laths, twins and cementite particles in the initial microstructure underwent distinct plastic strains and were gradually refined into nanostructures. Consequently, a gradient nanostructured（GNS） surface layer with a mean grain size of 24 nm at the top surface was obtained on the bearing steel, resulting in an increment of 20% in the surface hardness. Analyses based on microstructural evolution, phase constitution and in-depth hardness distribution revealed a mechanically induced formation mechanism of the GNS surface layer. The multiple surface severe plastic deformation under fine lubrication and cooling during SMRT contributed to the formation of a thick hardened surface layer on the bearing steel.
K.Zhang1,2，Z.B.Wang1
1. Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences2. University of Chinese Academy of Sciences
摘 要：In the present work, an ultrahigh strength bearing steel（AISI 52100） was subjected to surface mechanical rolling treatment（SMRT） at room temperature. Microstructural observations showed that martensitic laths, twins and cementite particles in the initial microstructure underwent distinct plastic strains and were gradually refined into nanostructures. Consequently, a gradient nanostructured（GNS） surface layer with a mean grain size of 24 nm at the top surface was obtained on the bearing steel, resulting in an increment of 20% in the surface hardness. Analyses based on microstructural evolution, phase constitution and in-depth hardness distribution revealed a mechanically induced formation mechanism of the GNS surface layer. The multiple surface severe plastic deformation under fine lubrication and cooling during SMRT contributed to the formation of a thick hardened surface layer on the bearing steel.
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