Environmental Degradation of Additively Manufactured Alloys: Poster Session
Sponsored by: TMS Structural Materials Division, TMS: Corrosion and Environmental Effects Committee
Program Organizers: Kinga Unocic, Oak Ridge National Laboratory; Luke Brewer, University of Alabama; Sebastien Dryepondt, Oak Ridge National Laboratory; Michael Kirka, Oak Ridge National Laboratory; Jenifer Locke, Ohio State University; Xiaoyuan Lou, Purdue University
Monday 5:30 PM
February 24, 2020
Room: Sails Pavilion
Location: San Diego Convention Ctr
C-9: Contrasting Corrosion and Cracking Behavior of Additively Manufactured and Wrought 17-4PH Stainless Steel: Trevor Shoemaker1; James Burns1; 1University of Virginia
Prior to use in demanding marine structural environments, additively manufactured (AM) alloys must be evaluated for corrosion and cracking performance. The current study compares and contrasts corrosion and cracking behavior of wrought 17-4PH stainless steel and its additively manufactured equivalent. Crack growth behavior as a function of stress intensity are investigated in a number of environments including humid air and NaCl solution mimicking seawater at number of electrochemical potentials. Fractography and microstructural analysis is used to aid in the characterization of underlying damage mechanisms. Results of this study will serve as a corrosion/cracking performance benchmark for the latest additive manufacturing processes versus existing wrought alloy capabilities applied to the 17-4PH material system.
C-10: Localized Corrosion of Selective Laser Melted Stainless Steel 316L: Duane Armell Macatangay1; Jonathan Skelton1; Wenhao Lin1; Robert Kelly1; Ji Ma1; 1University of Virginia
In recent years, additively manufactured metallic alloys such as 316L stainless steel produced by SLM have garnered attention due to opportunities in waste reduction, time and cost efficiency, and fabrication of geometrically complex structures. However, corrosion properties of SLM metal alloys are not well understood. The microstructure in materials produced by SLM is significantly different from that of its wrought counterpart, resulting in the presence of numerous heterogeneities that can ultimately lead to localized corrosion. This study characterizes the dependence of melt-pool boundary attack and intergranular corrosion and assesses a series of microstructure-based mechanisms responsible for the electrochemical behavior of these SLM 316L alloys. Galvanostatic etching, potentiodynamic scans, mass-loss testing, and accelerated testing of wrought and SLM 316L were used to reveal the localized corrosion behavior in these alloys. Focused ion beam and transmission electron microscopy was utilized to understand the microstructural origins of these observations.