Abstract
This research was directed at improving the wear resistance of Stellite 21 alloy by developing novel surface engineering technologies. To this end, a series of plasma Surface alloying (PSA) treatments with both carbon and nitrogen were conducted using a DC plasma unit with C-N bearing g-as mixture at temperatures ranging from 400 to 550 degrees C. The Surface alloyed layers were analyzed by XRD, GDS, SEM/EDX, TEM and a microhardness tester. Detailed tribological characterization was carried out by using a reciprocating tribometer in air and in 3.5% NaCl solution. Experimental results have demonstrated that C and N Supersaturated metastable phase, i.e. S-phase, can be formed by the PSA treatments with both carbon and nitrogen but at a high temperature of 550 degrees C, chromium nitrides precipitated in the surface treated layer. The surface hardness of Stellite 21 alloy can be significantly increased by 2-3 times following the PSA treatments. The wear factor of Stellite 21 alloy in air and in 3.5% NaCl solution can be reduced by 99% and 96%, respectively. (c) 2007 Elsevier B.V. All rights reserved.
Original language | English |
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Pages (from-to) | 157-165 |
Number of pages | 9 |
Journal | Wear |
Volume | 264 |
Issue number | 3-4 |
DOIs | |
Publication status | Published - 1 Jan 2008 |
Keywords
- plasma surface alloying
- Stellite 21
- wear
- carbon and nitrogen