高碳高铬堆焊焊条的研制及其堆焊合金显微组织分析

为了研制具有优良耐磨性能和硬度的高强钢耐磨堆焊焊条，设计了焊条药皮的配方，选用了焊条药皮的渣系，分析了药皮成分对焊接飞溅的影响规律。对研制的堆焊焊条（Fe-Cr-C、Fe-Cr-C-Nb）进行了焊接试验。试验结果表明，焊条药皮元素显著影响堆焊熔敷合金焊缝的气孔、飞溅等性能指标。显微组织分析表明，碳含量及铬－碳比对耐磨合金的碳化物方向、密度等分布状态起到决定性影响，随着其含量的增加，碳化物趋向垂直于堆焊层表面方向分布，合金的显微硬度和耐磨性不断提高，硬度最高值达到63HRC，相对磨损率为0.05；Nb元素的增加对显微硬度影响不大，但能使碳化物得以细化，分布更均匀，可以显著改善合金的耐磨性。

Development of High-carbon and High-chromium Hardfacing Electrode and Microstructure Analysis of the Hardfacing Alloy

In order to develop the wear-resistant surfacing electrode of the high strength steel with good wear-resistant properties, the formulation of the electrode coating was designed, the slag system of the electrode coating was selected, and the influencing rules of the coating composition on welding spatter was analyzed. The welding test of the surfacing electrode (Fe-Cr-C，Fe-Cr-C-Nb) was carried out. The results show that the element of the electrode coating has a significant effect on the weld porosity and spatter. Microstructure analysis shows that carbon content and chrome-carbon ratio play a decisive role in the distribution of carbide direction and density of the wear-resistant alloy. With the increase of the content, the carbide tends to be distributed perpendicular to the surface of the surfacing layer, and the micro-hardness and wear resistance of the alloy improve gradually. The maximum hardness reaches 63HRC, and the relative wear rate is 0.05. The increase of the element Nb has little influence on the micro-hardness, but it can make the carbide refined and distributed more evenly to improve the wear resistance of the alloy.