材料期刊网

目前,国内外对搅拌头材料W9Mo3Cr4V钢离子渗氮表面改性研究不多.采用金相分析、显微硬度测量、X射线衍射仪(XRD)等研究了离子渗氮温度对W9Mo3Cr4V钢搅拌头显微组织和性能的影响,从而得出制备高硬度耐磨氮化层搅拌头的合适的离子渗氮温度.结果表明:经离子渗氮的W9Mo3Cr4V钢搅拌头表层获得了主要由ε相(Fe3N)和y’相(Fe4N)组成的均匀渗氮层,且随着从表面到基体距离的增加,渗氮层的硬度呈现平缓的硬度梯度分布;480～560℃范围内,随离子渗氮温度升高,渗氮层厚度不断增加,渗氮层硬度也不断提高;ε相(Fe3N)衍射峰随离子渗氮温度升高而逐渐降低,γ’相(Fe4N)衍射峰则呈逐渐升高的趋势.渗氮层厚度ζ与渗氮温度T的关系满足ζ=3.85×108e-9141/T·τ.

Friction stir welding tool W9Mo3Cr4V was treated by ion nitriding,and the effects of plasma nitriding temperature on the microstructure and properties of ion nitrided layer were investigated by microscopic examination,microhardness determination and X-ray diffraction phase structure analysis.Furthermore,a suitable ion nitriding temperature for the preparation of a high hardness abrasion resistant nitrided layer stirrer was obtained.Results showed that after ion nitriding,a uniform nitride layer mainly composed of ε-phase (Fe3N) and γ'phase (Fe4N) was prepared on the friction stir welding tool W9Mo3Cr4V steel.With the increase of distance from the surface to matrix,the hardness of the nitride layer exhibited a gentle gradient distribution.Within 480 ～ 560 ℃,both the thickness and hardness of the nitride layer rose with the increase of ion nitriding temperature.With the rise of ion nitriding temperature,the diffraction peak of e-phase (Fe3N) was gradually lowered whereas that of γ'phase (Fe4N) was gradually increased.The relationship of the thickness of the nitride layer to the nitriding temperature complied with the formula ζ=3.85×108e-9141/T · τ.