Effects of rare earths on nanocrystalline for nitrocarburised layer of stainless steel |
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| Authors: | R. L. Liu |
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| Affiliation: | 1. Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin, China;2. National Key Laboratory for Precision Hot Processing of Metals, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin, China |
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| Abstract: | Solution-treated stainless steel was plasma-nitrocarburised at the precipitation-sensitive temperature with and without rare earth (RE) addition. The nitrocarburised layers were characterised by means of X-ray diffraction, transmission electron microscope, nanoindentation and anodic polarisation test. Experimental results show that the depth of plasma-nitrocarburised layer can be apparently increased from 60 to 75?μm after RE addition. More importantly, microstructure of stainless steel surface is refined into nano-sized grains after plasma nitrocarburising. At the depth of 20?μm, the hardness and the modulus of the nanocrystallised layer are as high as 13.6 and 218?GPa. After RE addition, the hardness and the modulus of the nanocrystallised layer increase to 17.5 and 255?GPa, respectively. |
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| Keywords: | Stainless steel plasma nitrocarburising precipitation-sensitive temperature nanocrystalline rare earths |
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