The GMAW-based wire and arc additive manufacturing is widely used for cost- and material-efficient production of medium to large metal parts. Nevertheless, the application of metal parts produced by WAAM depends on their mechanical properties. This paper investigates the impact of welding heat input (HI) on the microstructure and mechanical properties of solid WAAM parts. For this purpose, three blocks were deposited from low-carbon low-alloy steel with various welding parameters in a multi-pass multilayer way. The microstructure of the solid WAAM parts consists of the repetitive pattern of the primary constituent, which contains columnar, fine grain, and coarse grain zones. Changes in microstructure provoked by an increase in HI were correlated with hardness in each zone of the primary constituent, tensile, and impact toughness properties of the material. It was revealed that the increase in HI leads to the reduction of material hardness, yield, and ultimate tensile strength. At the same time, the percentage elongation after fracture and impact toughness of the material improve with the rise of HI. The anisotropy of the material was analysed based on the mechanical properties in longitudinal, vertical, and transversal directions. For filler wire selection, the properties of the WAAM material were compared to the properties specified in the wire certificate and the corresponding standard for welding wire, as well as to the properties of hot-rolled structural steels. The results showed that the G 42 4 M21 3Si1 (EN ISO 14341-A) wire is suitable to produce functional components using WAAM as an alternative for conventional subtractive manufacturing of parts from S275JR and S355JR structural steels taking static loads and impact loads.

基于 GMAW 的线材和电弧增材制造广泛用于大中型金属零件的成本和材料高效生产。然而，WAAM 生产的金属零件的应用取决于其机械性能。本文研究了焊接热输入 (HI) 对实心 WAAM 零件的微观结构和机械性能的影响。为此，以多道多层方式采用各种焊接参数从低碳低合金钢沉积三个块。实心 WAAM 零件的微观结构由主要成分的重复图案组成，其中包含柱状、细晶粒和粗晶粒区域。HI 增加引起的微观结构变化与主要成分的每个区域的硬度、拉伸、和材料的冲击韧性特性。结果表明，HI 的增加导致材料硬度、屈服和极限抗拉强度的降低。同时，材料的断裂伸长率和冲击韧性随着HI的升高而提高。基于纵向、垂直和横向的力学性能分析了材料的各向异性。对于填充焊丝的选择，将 WAAM 材料的特性与焊丝证书和相应焊丝标准中指定的特性以及热轧结构钢的特性进行了比较。