稀释率对埋弧焊制备WC增强堆焊层组织与性能的影响

Effect of Dilution Rate on Microstructure and Properties of WC-Fe Hard-facing Alloys Fabricated by Submerged Arc Welding

采用埋弧自动焊方法在Q235钢表面制备出原位合成的WC陶瓷颗粒增强堆焊合金耐磨层。借助光学显微镜和显微硬度计等试验仪器,考察了基体稀释率对堆焊层显微组织和性能的影响。结果表明:越靠近熔合线的区域,基体稀释率越大,对堆焊层组织和硬度的影响也越大。从堆焊层的上部到其底部,其显微组织碳化物呈Fe3W3C→WC→Fe3W3C变化规律。而堆焊层的显微硬度在中部时达到最大值而在底部时达到最小值。

WC particles reinforced hard-facing layer was prepared on the surface of Q235 steel by submerged arc welding. The effect of dilution rate on the microstructure and properties of the layer was investigated by optical microscopy and microhardness tester. The results show that the effect of dilution rate on the microstructure and microhardness is very significant, which corresponds to the dilution rate getting higher as the area approaches fusion line. The evolution of microstructure is as follows： Fe3W3C---,WC--,Fe3W3C. The microhardness of middle hard-facing layer is very high while the microhardness is very low at the bottom of hard-facing layer.