超高频脉冲GTAW熔池表面温度分布

Surface temperature distribution of molten pool by ultra high frequency pulsed GTAW

针对5 mm厚Ti-6Al-4V钛合金平板完成焊接熔池红外热成像监测,研究分析了超高频脉冲钨极氩弧焊（UHFP-GTAW）熔池表面温度分布,与常规GTAW（C-GTAW）熔池表面温度分布进行了比较。结果表明,在均为定点加热母材20 s的条件下,与C-GTAW工艺相比,UHFP-GTAW电弧（20 k Hz、40 k Hz）作用下的熔池中心表面温度测量值增加了10~30 K;分别以不同温度（678 K、823 K和968 K）为参考值测量熔池表面的高温扩散区域,UHFP-GTAW所得试样的高温扩散面积缩小范围为13%~30%。基于热量、力作用和复合散热等要素构建了熔池模型分析其温度场分布特点,计算结果与试验数据基本相符。

Thermal observation of molten pool was carried out with Ti-6Al-4V plates（ with thickness of5 mm）. The molten pool surface temperature distribution of ultra high frequency pulsed gas tungsten arc welding（ UHFP-GTAW） was collected and analyzed by infrared imaging monitor. Compared with conventional GTAW（ C-GTAW）,the test results indicate that the surface temperature of molten pool center increases by10- 30 K with UHFP-GTAW（ 20 k Hz,40 k Hz） after heating the base metal 20 seconds; meanwhile,the areas of the elevated temperature distribution were measured referring to varying temperature（ 678 K,823 K,968 K）,which are reduced by the range of 13%- 30%. A two-dimensional numerical model of molten pool was established,considering the essential factors such as heat flux,force and mixed heat transfer,to explore the characteristics of the temperature distribution in the molten pool. The calculated results of the above model are basically consistent with the test data.