Abstract The thermal history during the A-TIG welding and thermophysical properties of 309L stainless steel were measured using infrared thermometry and a thermal conductivity analyzer. A Manual-HKS weld scanner was introduced to detect the fluctuation of welding parameters, and changes in welding current were analyzed. The mean temperature at the measuring point increased when an active agent was added to the coating layer. Weld penetration increased from 2.8 mm to 5.24 mm compared with conventional tungsten inert-gas welding. The thermophysical properties of weld beads were switched with different contents of calcium fluoride, effusivity, thermal conductivity and diffusivity decreased with increasing calcium fluoride, a reverse was observed for calcium fluoride surpassed 3 wt.%. The microstructure of the welded region was found to contain equiaxed ferrite due to the proper heat applied and alloying element distribution. The obtained results can illuminate the mechanisms of penetration increase and changes in physical properties of weld beads.

中文翻译：

---

活性焊剂对309L不锈钢焊缝热物理性能的影响

摘要 采用红外测温仪和热导率分析仪测量了A-TIG焊接过程中的热历程和309L不锈钢的热物理性能。引入Manual-HKS焊接扫描仪检测焊接参数的波动，分析焊接电流的变化。当活性剂加入涂层时，测量点的平均温度升高。与传统的钨极惰性气体保护焊相比，焊缝熔深从 2.8 毫米增加到 5.24 毫米。焊道的热物理性质随氟化钙含量的不同而变化，随着氟化钙的增加，扩散性、导热性和扩散性降低，当氟化钙超过 3 wt.% 时观察到相反。由于适当的加热和合金元素分布，焊接区域的显微组织被发现含有等轴铁素体。获得的结果可以阐明熔深增加和焊道物理性能变化的机制。