Deformation (meteorology)

Low-cycle fatigue

Metallurgy

Materials science

Ultimate tensile strength

Fatigue testing

Ductility (Earth science)

Creep

Porosity

Strain (injury)

Internal medicine

Composite material

Fatigue limit

Medicine

International Journal of Fatigue

Static and fatigue experiments were conducted on conventionally manufactured (CM) and additively manufactured (AM) 17–4 PH stainless steels in ambient air. The fatigue experiments were tested under the fully reversed strain-controlled condition with the strain amplitudes ranging from 0.15% to 1.0%. The two manufacturing conditions result in similar tensile strengths but the AM 17–4 PH stainless steel has a significantly lower ductility than that of the CM steel. The fatigue limit of the CM 17–4 PH stainless steel is approximately 640 MPa and the fatigue limit of the AM steel is approximately 300 MPa. The strain-life fatigue curves of both materials display a kink point from low cycle fatigue regime to high cycle fatigue regime. Defects and porosity from the additive manufacturing process contribute to the weakened fatigue properties and ductility of the AM stainless steel.

Cyclic deformation and fatigue behavior of additively manufactured 17–4 PH stainless steel