Study on W-Mo-Y Multi-Elements Alloying and Plasma Nitriding on Q235 Steel

Abstract:

Using plasma alloying technique, Q235 steel was firstly treated by W-Mo-Y Multi-elements alloying followed by plasma nitriding process. The effects of process 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 alloying layer is columnar crystal, and 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 amounts of nitrides form and dispersedly distribute in the alloying layer. The phase of alloying layer consist of Fe₄N, Fe₃Mo, Fe, MoN, Mo₂N, W₂N, WN. The average micro-hardness of alloying layer is 850HV_0.05. And then the wear tests were conducted. Compared with untreated samples, the wear resistance of alloying layer is improved by 2 times under abrasive wear conditions.

• Periodical: Materials Science Forum (Volume 687)
• Pages: 745-749
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.687.745
• Online since: June 2011
• Authors: Yuan Gao, Bing Li, Xuan Nan Chen, Xue Feng Huang, Wei Zhang, Lin Yuan
• Keywords: Alloying, Plasma Nitriding, Q235

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