Fe-Cr-C-B系药芯焊丝的显微组织与耐磨性

为了研究药芯焊丝中Cr和B含量对堆焊层组织与性能的影响规律,采用自保护明弧堆焊法制备了Fe-Cr-C-B系耐磨药芯焊丝.利用光学显微镜、扫描电子显微镜和X射线衍射仪,对堆焊层的显微组织和耐磨性进行了分析.结果表明,适量的Cr、B可使堆焊层的性能更为优异.随着B元素的加入,堆焊层的显微组织由M_(23)C_6相向M_(23)(C,B)_6相转变,弥散分布的硼化物可呈层片状、菊花状等.硼化物显著改善了Fe-Cr-C-B系堆焊合金的耐磨性,且其耐磨性与硼化物的数量、致密度和尺寸有关,并最终确定了Cr和B元素的最佳质量分数.

Microstructures and wear resistance of Fe-Cr-C-B series flux-cored wire

In order to clarify the influence of Cr and B contents in the flux-cored wire on the microstructures and properties of surfacing layer, the Fe-Cr-C-B series flux-cored wire with wear resistance was prepared with self-shield open arc hardfacing method. In addition, the microstructures and wear resistance of surfacing layer were investigated with optical microscope(OM), scanning electron microscope(SEM)and X ray diffractometer(XRD). The results show that the appropriate amount of Cr and B elements can make the properties of surfacing layer more excellent. With the addition of B element, the microstructure of surfacing layer changes from M₂₃C₆ phase into M₂₃(C, B)₆ phase. The dispersed borides can be amellar-like and chrysanthemum-like shape. The borides significantly improve the wear resistance of Fe-Cr-C-B series hardfacing alloy, and the wear resistance is related to the quantity, tightness and size of borides. The optimal mass fraction of Cr and B elements are eventually determined.