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利用6 kW光纤激光器在Q235钢表面激光熔覆Ni基WC复合涂层。使用扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)、显微硬度计和磨损试验机,研究了不同WC颗粒含量下熔覆层组织形态、成分、显微硬度和磨损性能的变化规律。结果表明:熔覆层的稀释率随着WC含量的增加先减小后增加,当WC含量为20%时,稀释率最小。在光纤激光熔覆Ni基WC复合涂层的过程中,WC颗粒部分发生溶解并与其他元素相互作用形成共晶物,析出后分别以条状、块状和粒状等形态存在,随着WC含量的增加,熔覆层的组织出现细化现象。含WC的熔覆层组织中主要有γ-Ni、M_7C_3、M_(23)C_6、CrB、WC和W_2C等相存在。随着WC含量增加,熔覆层硬度增加,当WC质量分数达到40%时,熔覆层硬度可达到基体硬度的5倍以上。当WC的相对质量分数为20%时,熔覆层耐磨性能最好,耐磨性为Ni60A涂层的3倍以上。
Laser cladding of Ni-based WC composite coating on Q235 steel surface with 6 kW fiber laser. The morphology, composition, microhardness and microstructure of cladding layer under different WC particle contents were investigated by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), X-ray diffraction (XRD), microhardness tester and wear tester. Change rule of wear performance. The results show that the dilution rate of the coating decreases first and then increases with the increase of WC content. When the WC content is 20%, the dilution rate is the smallest. In the process of fiber laser cladding Ni-based WC composite coating, the WC particles partially dissolved and interacted with other elements to form eutectics, which were present in the form of strips, lumps and grains, respectively. With the WC content Increase in the cladding layer of the phenomenon of refinement. There are mainly γ-Ni, M_7C_3, M_ (23) C_6, CrB, WC and W_2C phases in the WC-containing cladding layer. With the increase of WC content, the hardness of the cladding layer increases. When the WC content reaches 40%, the hardness of the cladding layer can reach more than 5 times of the substrate hardness. When the relative mass fraction of WC is 20%, the wear resistance of the coating is the best, and the wear resistance is more than 3 times that of the Ni60A coating.