Invited: Downskin microstructure and heat treatability of Stainless Steel 17-4 Fabricated via Laser Powder Bed Fusion

Stainless steel 17-4 (17-4 PH SS) was developed specifically to contain chromium and nickel using precipitation-hardening as a martensitic stainless steel to be more cost effective than many high nickel non-ferrous alloys while maintaining high strength and hardness as well as corrosion resistance. This is particularly important for components requiring high-performance characteristics at temperatures up to 600°F (315°C) in applications including aerospace, chemical refining, and metalworking. This presentation will explain how the microstructure evolves as a function of the print angle in a support-free concept. The evolution will be shown using support-free coupons printed with angles including 30o, 20o, 15o, and 10o using laser powder bed fusion. The samples will also be heat treated using the typical schedule for this alloy. The microstructure differences will be characterized with optical microscopy, scanning electron microscopy and electron back scattering diffraction along with micro hardness data.