Microstructure, Residual Stresses, and Strain-Rate-Dependent Deformation and Fracture Behavior of AISI 304L Joints Brazed with NiCrSiB Filler Metals

The knowledge of alloy–process–structure–property relationships is particular interest for several safety-critical brazed components and requires a detailed characterization. Thus, three different nickel-based brazing filler metals were produced with varying chromium molybdenum content used to braze butt joints the austenitic stainless steel AISI 304L under vacuum. Two holding times evaluate diffusion-related differences, resulting in six specimen variations. Significant microstructural changes due formation location borides silicides demonstrated. Using X-ray diffraction, alloy-dependent residual stress gradients from seam base material determined thermal-induced stresses shown through simulations. For mechanical characterization, impact tests carried out determine toughness, as well tensile at low high strain rates strain-rate-dependent strength joints. Further thermal, electrical, magnetic measurements enabled an understanding deformation mechanisms. negative influence brittle phases center could be quantified showed most significant effects loading. Fractographic investigations subsequently enhanced fracture