摘要
Bulk nanostructured 316L austenitic stainless steel （SS） samples with nano-scale twin bundles embedded in nano-sized grains were synthesized by using dynamic plastic deformation （DPD）. Subsequent thermal an-nealing of the as-DPD sample leads to a single austenitic structure with static recrystallized （SRX） grains in nanostructured matrix. Oil-lubricated sliding tests of ball-on-disc type were carried out for the as-DPD and the as-annealed DPD steel samples in comparison with coarse grained （CG） steel samples. Experimental results show that the as-DPD 316L steel exhibits a little enhanced wear resistance under a load of 10 N, and nearly identical wear resistance under a load of 30 N relative to that of the CG sample. After annealing, the wear resistance roughly follows the Archard equation under a load of 10 N. However, the wear resistance increases with increasing hardness, and decreases with a further increase in hardness under a load of 30 N. The highest wear resistance can be found in the DPD sample annealed at 750 ℃ for about 20 min, which is more than 46% higher than that of the CG steel sample. This phenomenon is originated from the microstructure with an optimized combination of strength and ductility as a result of moderate plastic deformation in SRX grained regions.
Bulk nanostructured 316L austenitic stainless steel （SS） samples with nano-scale twin bundles embedded in nano-sized grains were synthesized by using dynamic plastic deformation （DPD）. Subsequent thermal an-nealing of the as-DPD sample leads to a single austenitic structure with static recrystallized （SRX） grains in nanostructured matrix. Oil-lubricated sliding tests of ball-on-disc type were carried out for the as-DPD and the as-annealed DPD steel samples in comparison with coarse grained （CG） steel samples. Experimental results show that the as-DPD 316L steel exhibits a little enhanced wear resistance under a load of 10 N, and nearly identical wear resistance under a load of 30 N relative to that of the CG sample. After annealing, the wear resistance roughly follows the Archard equation under a load of 10 N. However, the wear resistance increases with increasing hardness, and decreases with a further increase in hardness under a load of 30 N. The highest wear resistance can be found in the DPD sample annealed at 750 ℃ for about 20 min, which is more than 46% higher than that of the CG steel sample. This phenomenon is originated from the microstructure with an optimized combination of strength and ductility as a result of moderate plastic deformation in SRX grained regions.
基金
Financial supports from the MOST 973 Project (Grant No. 2012CB932201)
the International S&T Cooperation Project of China (Grant No. 2010DFB54010)
the National Natural Science Foundation of China (Grant No.51141008)
the CAS International Cooperation Project(Grant No. GJHZ1033)
the CAS-Croucher Funding Scheme for Joint Laboratories and the Danish-Chinese Centre for Nano-metals (Grant No. 50911130230)
