Metal Big Area Additive Manufacturing (mBAAM) offers the potential to fabricate large scale tools at high deposition rates (15 lb/h+). 410 martensitic steel is a potential tooling material, owing to its low cost, good machinability and reasonable printability. During the mBAAM process, the shielding gas can have a significant impact on the material properties as well as the process cost. Therefore, the current study aims to understand the effect of different shielding gas mixtures on large-scale additive manufacturing of 410 martensitic stainless steel. We show that an argon mixture with 3% nitrogen gas produced the best performance in terms of maximum hardness and tensile strength, with much less scatter in tensile strength. He-Ar-CO₂ or tri-mix shielded samples showed a low tensile strength with wide scatter, due to stabilized delta ferrite in microstructure during printing. Both tri-mix and Ar-CO₂ shielded samples showed slightly higher porosity. Thus, we recommend the use of argon-3% nitrogen as a shielding gas mixture for processing 410 steel for tool applications, based on the relatively low cost of this gas mixture and the resulting higher hardness, higher dimensional stability, and lower porosity.

金属大面积增材制造（mBAAM）提供了以高沉积速率（15 lb / h +）制造大型工具的潜力。410马氏体钢由于其低成本，良好的机加工性和合理的可印刷性而成为一种潜在的加工材料。在mBAAM过程中，保护气体会对材料性能以及过程成本产生重大影响。因此，本研究旨在了解不同保护气体混合物对410马氏体不锈钢大规模增材制造的影响。我们表明，在最大硬度和拉伸强度方面，含3％氮气的氩气混合物产生了最佳性能，而拉伸强度的散布却少得多。氦-氩-CO ₂由于印刷过程中微观结构中的δ铁素体稳定，因此三屏蔽或三混合屏蔽样品显示出较低的抗张强度和较大的分散性。三重混合物和Ar-CO ₂屏蔽样品均显示出较高的孔隙率。因此，我们建议使用3％的氩气作为保护气体混合物，以加工410钢用于工具应用，因为这种气体混合物的成本相对较低，并且具有较高的硬度，较高的尺寸稳定性和较低的孔隙率。