TiN对Fe-Cr-C耐磨堆焊合金组织及耐磨性影响

通过药芯焊丝的方式制备Fe-Cr-C-Ti-N和Fe-Cr-C堆焊层，讨论堆焊层中TiN对堆焊层耐磨性能和显微组织的影响. 利用洛氏硬度计检测堆焊层的宏观硬度，通过湿砂轮磨损试验机对堆焊层进行磨料磨损试验，利用X射线衍射仪(XRD)、扫描电镜(SEM)、能谱分析仪(EDS)、透射电子显微镜(TEM)等设备进行检测分析. 结果表明，含有TiN的堆焊层中，初生M₇C₃明显比不含TiN的组织细小，并且堆焊层硬度和耐磨性也相应提高. 通过热力学计算得出，熔池冷却过程中TiN先于M₇C₃析出. 由动力学计算可知TiN/M₇C₃的二维错配度为8.43%，TiN可做为初生M₇C₃的异质形核质点，使M₇C₃晶粒细化.

Effect of TiN on microstructure and wear resistance of Fe-Cr-C hardfacing alloy

Fe-Cr-C-Ti-N and Fe-Cr-C Surfacing layers were prepared by flux cored wires. The effect of TiN on the wear resistance and microstructure of the surfacing layer was discussed. The rockwell hardness tester was used to test the macrohardness of the surfacing layer. The abrasive wear test of the surfacing layer is carried out by the wet grinding wheel wear tester. Using X ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and other equipment for testing and analysis. The results showed that the primary M₇C₃ in the surfacing layer containing TiN was significantly smaller than that without TiN and the hardness and wear resistance of the surfacing layer were also improved. Through thermodynamic calculation, TiN is prior to precipitation of M₇C₃ in molten pool cooling process. According to the dynamics calculations, the two-dimensional misfit of TiN/M₇C₃ is 8.43%. TiN can be used as a heterogeneous nucleation site for primary M₇C₃, which refines the M₇C₃ grains.