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Metal material surface nano based on does not change the base chemical composition and the appearance shape of the preparation out from the surface to the substrate continuous transition of the nano-crystal layer, in order to improve the material of the overall service performance, is considered to be metal materials modified the development direction has broad application prospects. However, due to the limitations of the technology and equipment, only small samples were prepared, and not enough into industrial applications. The subject using a high-speed rotating wire caused by severe plastic deformation experimental device, 316L stainless steel surface treatment, to explore the feasibility of austenitic stainless steel surface nano. The use of optical microscope, X-ray diffraction, scanning electron microscopy and transmission electron microscopes and other equipment research sample microstructure changes. The micro hardness meter on the treated sample surface hardness test. The results show that: the treatment after deformation of the high-speed rotating wire, 316L stainless steel surface grain refinement to the nanometer size up to 12nm, grain size gradient distribution in the depth direction, and is gradually increased to the original grain size; surface significantly microhardness of 450HV the matrix hardness 180HV, compared to nearly 2-fold increase, the microhardness gradually decreased with the increase of depth from the surface layer, and coincide with changes in the microstructure. On the the nano sample after the cold rolling process, to eliminate nano caused by the increase in surface roughness. Rolled samples surface roughness, microstructure and mechanical properties testing, research rolling nanocrystalline layer. The results show that: after the cold rolling process, the roughness by Rα of ≈ 3.5 μm, Rz of ≈ 15μm, reduce Rα of ≈ 1.1μm, Rz of ≈ 7μm; grain size decreases further reduced to about 12nm after deformation by a high-speed rotating wire approximately 9nm; material hardness of the matrix increases sharply to primordia body twice, while the plastic dropped significantly, the percentage elongation, from 95% to 52%. Vacuum annealing at different temperatures on the sample after the rolling treatment, in order to find a suitable temperature range, to eliminate deformation strengthening basis, to maintain the stability of the nano-crystalline. The results show that: at 773K or less, the grain size increases the amplitude is small, can be considered the surface nanocrystalline can be stable at 773K, when the annealing temperature reaches 973K by 9nm, grain size is increased to 40nm, a significant grew; after the annealing process, the release of residual stress-induced martensitic transformation, and with the increase in the treatment temperature, the amount of martensite is more and more; the 773K anneal 1h, the surface micro-hardness of about 400 HV, the hardness of the base body is substantially back to the rolling processing pre hardness.
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