ICF15 Fatigue.pdf

Researchers from Karlstad University, Sweden, investigated the high cycle fatigue properties of additively manufactured (AM) hot work tool steel (AISI H13 mod) and compared it to conventional ingot cast and forged AISI H13 steel.
Fatigue tests were performed using servohydraulic and ultrasound equipment, combined with microstructural characterization to determine fatigue properties, crack initiation mechanisms, and defect types and distributions.
Results showed that the AM steel had a similar fatigue strength to the conventional steel, but with different defect types controlling fatigue initiation, including lack-of-fusion defects and pores.
Fatigue strength models were evaluated, and it was found that the model developed by Murakami and co-workers, which relates fatigue strength to defect size, may not be directly applicable to AM steel due to the different defect types present.
* The study highlights the need for further research into the fatigue properties of AM steel and the development of new models that can accurately predict fatigue behavior.