Přednášející
Popis
Fatigue crack initiation and propagation play an important role in fatigue properties, where they are shown to be strongly associated also with macroscopic residual stresses (RS). During additive manufacturing using the selective laser melting technology, a complex residual stress distribution is created that can significantly affect the printing itself and also the mechanical properties of the final product. The magnitude of these stresses may even approach the yield strength of the material. Thus, research has been carried out to optimize 3D printing parameters to minimize residual stresses in MS1 maraging steel. Macroscopic RS were determined using X-ray diffraction and hole drilling. It was found that the preheating temperature of the build platform significantly affects the residual stresses, especially in the vicinity of the building platform. For both samples, the tensile residual stresses near the surface still dominate, but a rapid decrease in residual stresses can be observed for the sample with platform preheating to 120°C.
