热绝缘剂在碳化钨堆焊中的应用研究

Application of Heat Protection Agent in Tungsten Carbide Bead Welding

根据热绝缘剂在碳化钨堆焊中的应用原理 ,进行了含热绝缘剂的管装铸造碳化钨焊条的 TIG电弧堆焊试验。堆焊层试样的金相和电镜分析结果表明 ,采用 2号热绝缘剂堆焊 ,可使堆焊层中碳化钨硬质相颗粒的面积分数 Ac由原来的 5 %～ 8%提高到 2 1 %～ 2 9% ,碳化钨的熔损有明显降低 ,堆焊层洛氏硬度达到 HRC6 7以上。堆焊层线性磨损量 Δl与碳化钨颗粒面积分数 Ac的关系为 Δl=0 .0 2 2 9- 5 .5 4× 1 0 - 2 Ac。初步说明热绝缘剂在碳化钨复合合金耐磨堆焊技术中的使用效果。

According to the principle of heat protecting of the tungsten carbide hardfacing technology, three type pipe welding wires contained tungsten carbide and insulator were used for tungsten-inert-gas arc welding (TIG) test. The results of metallographic examination and ESCA analysis show that the area fraction of tungsten carbide hard phase in hard-facing has reached 21%~29% by the application of No.2 insulator, over 5%~8% area fraction in conventional welding process without heat protecting technology. The melt wastage of tungsten carbide particle phase in bead welding decreases obviously and ball hardness of hardfacing attains HRC 67.9. It has been proved that the heat insulator pays an important role in the tungsten carbide composite alloy wear-resistance bead welding, and the relation between wear length Δ l and area fraction Ac can be described as the following equation:Δ l =0.0229-5.54×10 -2 A c .