GAAS80焊机焊接U76CrRE钢轨工艺研究

分析了GAAS80/580焊接原理,结合GAAS80闪光焊机焊接工艺特点,制定了U76CrRE钢轨的焊接工艺。采用落锤试验检验焊头质量,并对断口形貌进行扫描,能谱分析表明,断口缺陷处低熔点共晶硫化物的形成是裂纹产生的主要原因。在此基础上优化焊接工艺参数,降低预热阶段的电压、减小烧化阶段的位移、提高烧化阶段的闪光速度。优化后的U76CrRE钢轨焊接工艺通过了落锤试验,各项力学性能符合铁道部钢轨焊接标准的相关要求。

Study on welding parameters of U76CrRE rail welded by GAAS80 /580 welder

The welding parameters of U76CrRE rail were established according to the process characteristics of GAAS80 flash welding machine and the welding principle of GAAS80 /580 welder. The welded joint quality was tested by the drop-hammer test,and the fracture surface morphology was observed through scanning electron microscope. Energy spectrum analysis showed that the formation of low melting point eutectic sulfide near the fracture defects is the main cause of cracks. Then the welding parameters were optimized,including the reduction of the preheating phase of voltage and the flashing phase of displacement and the increase of the burnt phase of flash rate. The optimized U76CrRE rail welding parameters passed the drop-hammer test and the mechanical properties reached the relevant requirements of the rail welding standard of the Ministry of Railways.