Research on W-Mo-Y Multi-Elements Co-Diffusion Treatment and Plasma Nitriding

Abstract:

Using plasma alloying technique, Q235 steel was firstly treated by W-Mo-Y Multi-elements co-diffusion followed by plasma nitriding process. And then the wear tests were conducted. The effects of technological parameters on alloying layer were studied. The structure, composition, phase and micro-hardness of alloying layer were analyzed by metalloscope, XRD, SEM and microhardness tester. Results show that the microstructure of W-Mo-Y Co-diffusion layer is columnar crystal; W, Mo contents decrease from the outside to the inside. The element Y is distributed mainly at the grain boundaries. The phase of alloying layer consisted of Fe, Fe₃Mo, Fe₁₇Y₂ and the solid solution of (W, Mo, Y) in α-Fe. After plasma nitriding process, the co-diffusion layer is strengthened and large amount of nitrides form and dispersedly distribute in the alloying layer. After nitriding the phase of alloying layer consist of Fe₄N, Fe₃Mo, Fe, MoN, Mo₂N, W₂N, WN. the average micro-hardness is 850HV_0.05. Compared with untreated samples, the wear resistance of alloying layer is improved by 2 times under abrasive wear conditions.

• Periodical: Materials Science Forum (Volumes 704-705)
• Pages: 1146-1151
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.704-705.1146
• Online since: December 2011
• Authors: Yuan Gao, Cheng Lei Wang, Bing Li, Xuan Nan Chen
• Keywords: Co-Diffusion, Plasma, Plasma Nitriding, Rare Earth (RE)

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