含WC镍基药芯焊丝MIG堆焊层的组织与性能

Microstructures and Properties of the Hardfacing with WC/Ni-based Flux Cored Wire Deposited by MIG

用MIG堆焊的方法,在Q235上制备WC颗粒增强镍基耐磨堆焊层,利用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)等方法对堆焊合金的显微组织进行了观察分析,对堆焊层的硬度和耐磨性进行了测试分析。结果表明:堆焊层的基体组织为Ni基固溶体,其上分布着Ni3B、Ni3Si等硬质相,这些硬质相与未熔WC颗粒构成了耐磨相,起到减磨耐磨的作用,镍基基体起到支撑作用,使得堆焊层具有良好的耐磨性。WC含量一定时,随着热输入的增大,WC颗粒的溶解使得堆焊层的硬度从45HRC降低至35.6HRC;随着WC含量的增加,堆焊层中WC硬质相的体积分数增多,使其抗磨粒磨损性能较Ni-B-Si基体从7.83倍提高至8.7倍。

WC/Nibased hardfacings were prepared on Q235 using metal inertia gas （MIG） welding, analyzed by optical microscopy, scanning electron microscopy （SEM） and Xray diffraction （XRD）. Abrasionresistant properties and hardnesses of depositions were also analyzed. The results show that Ni3B and Ni3Si hard phases are distributed on the surface of Ni matrix, with unmelted WC particles. They constitute rich wear resistance phases, acting as the wearable skeleton. The Nibased substrate plays a supporting role, showing good wear resistance. When the content of WC is fixed, the hardness of the hardfacing alloy decreases （4535.6 HRC） with the increasing of welding current. With the increase of the WC content, the abrasionresistance of the hardfacing increases （7.838.70 times）.