The corrosion-resistant and high-strength stainless steel 17-4PH or X5CrNiCuNb17-4-4 (1.4528) is commonly used in power engineering. The processing of the 17-4PH material by powder bed fusion (PBF) using a laser beam (LB) (PBF-LB) can be regarded as mostly established. However, while the static strength of AM structures is largely comparable to that of conventional manufactured materials, a significant decrease in fatigue strength is observed. This degradation in fatigue strength is primarily attributed to present defects in the material. For the use of AM in safety-relevant components exposed to fatigue loading, it is therefore inevitable to understand their process-structure-property linkage.

This article focuses on the characterization of the mechanical behavior of PBF-LB manufactured 17 4PH under static and cyclic loading. Conventional and AM specimens are compared, taking three different building directions with two surface conditions into account. Fatigue results up to 1010 load cycles are used to evaluate the influence of the AM processing strategy, building orientation and surface condition on the fatigue performance of 17 4PH. A recommendation for the structural design of additively manufactured components under fatigue load is developed based on extensive fracture surface analysis and analytical models.