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使用扫描电镜、能谱仪、X射线衍射分析仪和高温摩擦磨损试验机研究了Nb元素对低碳Stellite合金激光熔覆层显微组织、元素分布、相组成及常温和高温磨损性能的影响。结果表明,添加Nb元素使熔覆层相组织细化,稍高的含碳量与Nb元素的共同作用使其比原合金强化相的体积分数增加了近1倍。熔覆层显微组织主要相由γ-Co以及强化相Co_3Mo、NbC组成。在常温磨损试验中,含Nb熔覆层磨损机理以粘着磨损为主。在400℃的高温磨损下,由于碳化物硬质相Nb C的作用,含Nb元素的熔覆层比原熔覆层高温耐磨性提高了1倍。熔覆层的高温磨损形式主要以氧化磨损、粘着磨损为主。
The effects of Nb on microstructure, elemental distribution, phase composition and wear properties at room temperature and high temperature of the laser cladding layer of low carbon Stellite alloy were investigated by SEM, EDS, X-ray diffraction and high temperature friction and wear testing machines. The results show that the addition of Nb can refine the microstructure of the coating, and the slightly higher carbon content and the addition of Nb can increase the volume fraction of the alloy by nearly one time. The main phase of cladding microstructure consists of γ-Co and strengthening phases Co_3Mo and NbC. In the normal temperature wear test, the wear mechanism of the Nb-containing coating is mainly adhesive wear. Under high temperature wear of 400 ℃, due to the effect of Nb C, the wear resistance of Nb-containing coating is two times higher than the original coating. The main wear and tear of the cladding is oxidation wear and adhesive wear.