Growth model of hard phase in layer surfaced with Fe-Cr-Ti-C flux cored wire

The Fe-Cr-Ti-C series of wear-resistant flux cored wire was surfaced on low carbon steel by GTAW method. The phase composition, distribution and growth mechanism of hard phase in surfacing layer were studied. The reasons for the increasing of abrasion resistance and surface hardness were discussed as well. The results show that the alloy elements of flux cored wire could effectively translate into surfacing layer, in-situ synthesis of (Fe,Cr)₇C₃ and TiC hard phase were obtained. TiC preferentially nucleated and grew up by attaching to external interface, the nucleation and growth of eutectic (Fe,Cr)₇C₃ hard phase was dependent on the primary martensite phase and TiC. Most of TiC hard phase was punctate, the minority was the strip and cross shaped. They dispersed in the matrix of martensite, and formed composite hard phase with (Fe,Cr)₇C₃, which could significantly improve the wear resistance of the surfacing layer.