Of late, wire arc additive manufacturing (WAAM) is extensively used in the aerospace and automotive fields to produce large complex metallic components. The water‐bath method is applied for active cooling to address the heat accumulation problem in WAAM. Herein, the modified water‐bath method with a changing level is used to realize different phase transformations, and the microstructure and mechanical properties of the sample are investigated. Heat accumulation in the sample is eliminated using the modified water‐bath method. Furthermore, the microstructure of the fabricated sample shows a mixture of polygonal ferrite (PF), upper bainite (UB), and lath bainite (LB). Layer bands are formed in the entire sample, except in the final layer, and equiaxed ferrite (EF) and an increased fraction of PF appear in these zones. The microhardness and tensile property are enhanced due to the fine LB. The considerable difference in the microhardness between LB and PF causes an obvious wave of hardness, and the tensile property along the horizontal direction is better than the vertical. This study is expected to help broaden the application of the water bath in the microstructure control.

中文翻译：

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改进的水浴法对电弧焊添加低碳低合金钢组织和力学性能的影响

最近，电弧增材制造（WAAM）广泛用于航空航天和汽车领域，以生产大型复杂的金属零件。水浴方法用于主动冷却，以解决WAAM中的热量累积问题。在此，使用改变水平的改进​​水浴方法来实现不同的相变，并研究样品的微观结构和力学性能。使用改进的水浴法可以消除样品中的热量积聚。此外，所制备样品的显微组织显示出多边形铁素体（PF），上贝氏体（UB）和板条贝氏体（LB）的混合物。除最终层外，在整个样品中都形成了层带，在这些区域中出现了等轴铁氧体（EF）和PF含量增加。细的LB提高了显微硬度和拉伸性能。LB和PF之间显微硬度的巨大差异导致明显的硬度波动，并且沿水平方向的拉伸性能优于垂直方向。预期该研究将有助于扩大水浴在微结构控制中的应用。