Wire- and arc-based additive manufacturing (WAAM) is a promising technology for large-scale additive manufacturing of metallic components. However, due to the high heat input by the electric arc, interpass cooling time decelerates the average manufacturing speed. Since future applications aim to the production of large structural steel components, the manufacturing speed is a key parameter to make WAAM usable for civil engineering. Within the scope of this paper, different process cooling strategies are weighed up against one another with regard to efficiency, impact on the process, as well as to the influence on the microstructure of the processed steel. For the thermal evaluation, welds on vertically placed plates were performed using the gas metal arc (GMA) process. As far as different cooling methods are concerned, the standard GMA process is carried out with water bath cooling, high-pressure air cooling and also with aerosol cooling. Temperature curves were determined using thermocouples which are dipped into the molten pool. The evaluation of the microstructure and the hardness is carried out by means of cross sections and Vickers hardness tests. The results show that aerosol cooling can be a promising addition to WAAM as it can be applied during welding and is capable to modify the t_8/5 time and, therefore, the mechanical properties of the steel.

中文翻译：

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通过先进的冷却策略提高WAAM的制造效率

基于线和电弧的增材制造（WAAM）是用于金属零件的大规模增材制造的有前途的技术。然而，由于电弧输入的热量高，道间冷却时间降低了平均制造速度。由于未来的应用旨在生产大型结构钢部件，因此制造速度是使WAAM可用于土木工程的关键参数。在本文的范围内，在效率，对工艺的影响以及对加工钢的微观结构的影响方面，权衡了不同的工艺冷却策略。为了进行热评估，使用气体保护电弧（GMA）工艺在垂直放置的板上进行焊接。就不同的冷却方法而言，GMA的标准工艺是通过水浴冷却，高压空气冷却以及气溶胶冷却进行的。使用浸入熔池中的热电偶确定温度曲线。通过横截面和维氏硬度测试进行显微组织和硬度的评估。结果表明，气雾冷却是WAAM的有希望的补充，因为它可以在焊接过程中应用，并且能够改变t _8/5时间，因此是钢的机械性能。