本研究为了提高截齿的性能, 延长截齿的使用寿命。本实验使用大功率宽带半导体激光设备, 在42CrMo基材上制备了超硬复合材料, 获得了与基材紧密结合的高硬度, 高耐磨性熔覆层。研究结果表明: 熔覆层的硬度可达到855.6 HV0.3, 将基体硬度提高了3.45倍; 在基体的热影响区, 部分基体硬度可达到550 HV0.3; 熔覆层的摩擦系数与失重量均比基体的摩擦系数与失重量小, 提高了截齿的抗磨损性能; 熔覆层厚度可以达到1 351 μm; 当功率为3 500 W时, WC开始大量的熔解, 并与其他的元素相结合, 形成树枝状、块状的共晶物, 其成分主要是由Fe、Co、Cr、W等元素组成; 熔覆层中不同梯度元素含量的变化导致熔覆层各个梯度的性能出现差异, Fe、Cr、Si、W元素的改变是影响熔覆层中硬度变化的内在因素; WC颗粒周围存在微小的树枝状晶体, 有利于防止WC颗粒的脱落, 提高熔覆层耐磨性及硬度; 铁基碳化物涂层能够增强截齿性能, 减少截齿在应用过程中损伤, 延长截齿的使用寿命。

The article is to improve the performance of the pick and prolong its service life. A super-hard composite material was prepared on a 42 CrMo substrate using a high-power broadband semiconductor laser device in this experiment, and a high-hardness and high-wear-resistant cladding layer was obtained which was closely bonded to the substrate. The change of microstructure and element content in cladding layer and heat affected zone and its influence on its properties were analyzed. The results show that the hardness of the cladding layer can reach 855.6 HV 0.3, which increases the hardness of the matrix by 3.45 times. In the heat affected zone of the substrate, the hardness of some substrates can reach 550 HV 0.3; The friction coefficient and weight loss of the cladding layer are smaller than those of the matrix, which improves the wear resistance of the pick. The thickness of the cladding layer can reach 1 351 μm. When the power is 3 500 W, WC begins to melt in large quantities and combine with other elements to form dendritic and massive eutectic, which is mainly composed of Fe, Co, Cr, W and other elements. Changes in the content of different gradient elements in the cladding layer lead to differences in the properties of each gradient of the cladding layer. Changes in Fe, Cr, Si and W elements are the internal factors affecting the hardness changes in the cladding layer. The existence of tiny dendrites around WC particles is conducive to preventing WC particles from falling off and improving the wear resistance and hardness of the cladding layer. Iron carbide coating can enhance the performance of cutting teeth, reduce the damage of cutting teeth and prolong the service life of cutting teeth.