基于热传导的热丝TIG焊接技术

Hot-wire TIG welding based on the heat-conduction

基于热传导方式构建热丝TIG焊接装备,建立热丝温控数学模型,并验证此温控数学模型在一定送丝速度区间内能够将焊丝温度维持在220℃,误差范围±5℃。开展220℃热丝TIG焊与普通TIG焊的对比试验。结果表明:基于热传导的热丝TIG焊能够改善焊接成形,提高送丝速度和焊接速度。在获得质量接近的焊接成形时,由于热丝TIG焊焊丝对电弧的激冷作用较小,因而220℃热丝TIG焊的打底焊接效率较普通TIG焊提高了约100%,填充盖面焊接效率提高了约200%。此外,在获得质量接近的焊接成形时,其焊缝区显微组织较普通TIG焊的更为细小,焊缝区硬度略高于普通TIG,两种焊接接头力学性能良好,断裂位置均在ASTM A106钢母材。

The hot-wire TIG welding equipment was built based on the heat-conduction method. The temperature-controlling model was developed and verified within a certain temperature range. The results showed that the wire temperature could be maintained at （220±5）℃. The comparing experiments between the hot-wire TIG at temperature of 220 ℃ and ordinary TIG were conducted. The results showed that the hot-wire TIG based on the heat-conduction method could improve the appearance and the feeding speed. When the appearance was similar,due to the chilling effect of hot wire TIG welding wire on arc is small, the efficiency of hot-wire TIG in bottom welding was doubled compared with that of the ordinary TIG. The efficiency of hot-wire TIG in cover welding was tripled compared with that of the ordinary TIG. Moreover,the microstructure of welding seam of the hot-wire TIG welding was finer than that of the ordinary TIG welding. The hardness of welding seam of the hot-wire TIG welding was harder than that of the ordinary- TIG welding slightly. The mechanical property of the two joints was well. The fi＇acture was located in the ASTM A106 base metal.