Effects of Temperature and Time on the Diffusion Bonding of 316L Stainless Steel and H13 Hot Work Tool Steel

This study examines the diffusion bonding of 316 L stainless steel and H13 hot work tool steel, aiming to optimize process parameters and assess the resulting microstructural and mechanical properties. Both materials were bonded at varying temperatures (700, 750, and 850 °C) and times (15, 30, and 60 min). The joints are analyzed using scanning electron microscopy (SEM), energy-dispersive spectroscopy, and X-ray diffraction (XRD) to evaluate interfacial morphology, chemical composition, and phase formation. Microhardness measurements indicate an increase in hardness from the 316 L side to the H13 side, suggesting intermetallic phase formation. Shear strength tests show the highest strength at 850 °C for 30 min, with longer times leading to strength reduction due to brittle intermetallic compounds. SEM analysis reveals improved bonding interfaces with fewer voids at higher temperatures and longer times, but the Kirkendall effect causes void formation, negatively impacting mechanical properties. XRD confirms α-Fe and γ-Ni phases, with Fe3C forming at 850 °C for 60 min. This study underscores the importance of process parameters in optimizing joint properties and minimizing brittle phase formation, providing insights for industrial applications requiring robust and corrosion-resistant joints.