In this paper, we report a thorough study of phase formation in Fe-Nb weld metals using a combination of microscopy and composition analysis. The correlation of microstructure and mechanical properties was established by nanoindentation. A simplified scenario of weld formation was proposed. Nb weld metal was dominated by the coarse Laves phase (Fe2Nb) with high hardness (∼20.4 GPa). With the addition of Cu, sound weld metal was obtained with alternative distribution of α-Fe, Cu phases and fine eutectic phases (α-Fe + Fe2Nb). These transformation products with lower hardness (α-Fe + Fe2Nb ∼ 11.6 GPa) improved the overall mechanical properties of the weld metal.

中文翻译：

---

Cu对Fe-Nb异种焊缝组织演变及力学性能的影响

在本文中，我们报告了结合显微镜和成分分析对 Fe-Nb 焊缝金属中相形成的深入研究。通过纳米压痕建立微观结构和机械性能的相关性。提出了一种简化的焊缝形成方案。Nb 焊缝金属主要由具有高硬度 (~20.4 GPa) 的粗 Laves 相 (Fe2Nb) 支配。添加 Cu 后，获得了具有 α-Fe、Cu 相和细共晶相 (α-Fe + Fe2Nb) 交替分布的良好焊缝金属。这些硬度较低的转变产物（α-Fe + Fe2Nb ∼ 11.6 GPa）提高了焊缝金属的整体机械性能。