Research on Microstructures of Alloyed Layer by Plasma Surface Alloying with Tungsten and Molybdenum

Abstract:

The alloying elements W-Mo cementation is carried out on the surfaces of low carbon steels by the technique of plasma metallurgy. Then by using the plasma-supersaturated carbonization, the composition of surface alloying layer reaches or approaches that of low-alloy HSS. In the end the surface alloying layer possesses high hardness, favorable red hardness and a significant improvement in properties after high temperature quenching and high temperature tempering. The surface cementation structure and phase structure of alloying layer were analyzed using metallographic microscope and X-ray diffraction (XRD), respectively; the distribution of surface composition and hardness of the layer were investigated by Glow Discharge Analytical Instrument (GDA) and micro hardness instrument, respectively; the resistance to wear was tested by a abrasion machine. The experimental results indicated that the layer consisted of W-Mo solid solution in Fe, the depth of the layer could reach 100µm and the content of tungsten exceeded 10% after ion W-Mo cementation. The carbon content of carburized layer was 1.3% above, which was composed of M6C carbide containing a lot of elements of W-Mo. The surface hardness of the alloying layer attained the HV1000 or so and appeared graded distribution after quenching and tempering. The application study showed that alloying elements W-Mo cementation was an appropriate technique to enhance surface resistance to wear and prolong operating life of accessories.

• Periodical: Key Engineering Materials (Volumes 297-300)
• Pages: 1108-1112
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.297-300.1108
• Online since: November 2005
• Authors: Gao Yuan, Jin Yong Xu, Yan Ping Liu, Jian Zhong Wang, Xiaoyun Kui, Zhong Xu
• Keywords: Carbide, Diffusion Layer, Low-Alloy HSS, Plasma, Surface Alloying

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