Mechanical Performance of Additively Manufactured ODS 316L and 316H Stainless Steels

This work package within the Advanced Materials and Manufacturing Technologies (AMMT) program focused on the mechanical and microstructural characterization of oxide dispersion strengthened (ODS) stainless steels produced using advanced manufacturing techniques.The research aimed to identify an accelerated development path for ODS alloys by integrating additive manufacturing (AM) technologies with recent advancements in ODS materials and traditional manufacturing methods.For FY 24, the research specifically targeted exploring an accelerated development path for ODS alloys by combining AM technologies with these advancements.Novel AM and post-build processing routes were developed for ODS austenitic alloys, including Fe-Cr-Ni alloys such as 316L and 316H.Electron microscopy and mechanical characterizations were conducted to evaluate the impact of process variables on microstructure and properties, with the goal of optimizing these properties economically.Traditionally, producing ODS alloys involves multi-day, high-energy mechanical milling of alloy powder with yttria powder, followed by milled-powder consolidation through extrusion or other methods, and additional thermomechanical processing (TMP) for property control.To overcome the challenges associated with this complex and costly approach, we propose exploring alternative, cost-effective processing routes that emphasize AM and traditional TMP methods.The new processing routes for ODS alloys have achieved significantly higher strengths-several times greater than those of wrought stainless steels-while maintaining substantial ductility and fracture toughness.This report outlines the novel and economical AM-based processing routes for ODS austenitic alloys, combined with post-build TMPs, and discusses the mechanical and microstructural characteristics of the developed materials.