Effects of Stress-Relieving Temperature on Residual Stresses, Microstructure and Mechanical Behaviour of Inconel 625 Processed by PBF-LB/M

Inconel 625 (IN625) superalloys can be easily fabricated by the laser-based powder bed fusion (PBF-LB/M) process, allowing production of components with a high level design freedom. However, one main drawbacks PBF-LB/M process is control over thermally induced stresses and their mitigation. A standard approach to prevent distortion caused residual stress performing stress-relieving (SR) heat treatment before cutting parts from building platform. Differently cast or wrought alloy, in additively manufactured IN625, SR at 870 °C provokes early formation undesirable δ phase. Therefore, this unsuitable precipitation observed material drives attention develop tailored minimise presence phases. This work investigates lower temperatures simultaneously considering effects on mitigation, microstructural evolution, mechanical properties. multiscale cantilever X-ray technologies was used investigate how affected temperature. Moreover, analyses phase identifications were performed SEM, XRD, EBSD, DSC analyses. Finally, investigations through microhardness tensile tests as well. The results revealed that for IN625 parts, an alternative able mitigate without massive could temperature range between 750 800 °C.