Environmental Degradation of Additively Manufactured Alloys: On-Demand Oral Presentations
Sponsored by: TMS Structural Materials Division, TMS: Corrosion and Environmental Effects Committee, TMS: Additive Manufacturing Committee
Program Organizers: Kinga Unocic, Oak Ridge National Laboratory; Jenifer Locke, Ohio State University; Sebastien Dryepondt, Oak Ridge National Laboratory; Xiaoyuan Lou, Purdue University; Elizabeth Trillo, Southwest Research Institute; Andrew Hoffman, GE Research; Brendy Rincon Troconis, University of Texas at San Antonio

Monday 8:00 AM
March 14, 2022
Room: Corrosion
Location: On-Demand Room

Effect of Oxygen on Corrosion Resistance of Stainless Steel 316L Prepared by Powder Bed Fusion: Xiaolei Guo1; Eric Schindelholz1; Hsien Lien Huang1; Menglin Zhu1; Szu-Chia Chien1; Karthikeyan Hariharan1; Ngan Huynh1; Jinwoo Hwang1; Wolfgang Windl1; Gerald Frankel1; 1Ohio State University
    Despite the rapid development of AM techniques such as powder bed fusion (PBF) and the accompanying substantial advancement of the understanding of various physiochemical properties of materials prepared by this technique, there is a clear knowledge gap concerning the impact on corrosion properties. In this work, we explored the dissolution kinetics of the PBF-prepared and wrought SS316L using an artificial pitting corrosion approach, which enables the assessment of its corrosion resistance under an aggressive but well-defined pit environment. A modified syringe cell was also used to evaluate their pitting potential, thus minimizing the influence of crevice corrosion. In general, PBF-produced SS316L exhibits higher corrosion resistance. The underlying mechanism was further studied by leveraging advanced high-resolution scanning transmission electron microscopy and first principles simulation. We have evidence from imaging and calculations that the enhanced corrosion resistance of AM SS316L stems from the higher oxygen content compared to the wrought counterpart.

High Temperature Oxidation of Additively and Conventionally Manufactured Heat Resistant Steel: HK30Nb: Marie Romedenne1; Bruce Pint1; Michael Lance1; Kinga1; Sebastien Dryepondt1; 1Oak Ridge National Laboratory
     The electrification of vehicles will drive the need to further cut CO2 emission of medium and heavy-duty diesel engines. Stringent fuel efficiency standards will need to be achieved for example by increasing temperatures, loads and optimizing engine parts’ geometries. Therefore, materials that could withstand these harsher conditions are under investigation. Additively manufactured material HK30Nb (Fe-25Cr-20Ni-01.5Nb) is currently of interest for its higher strength between 700 and 900C than conventionally used SiMo cast iron materials. Additive manufacturing can result in variation in the HK30Nb composition (Mn content) and grain microstructure compared to cast HK30Nb. The influence of these parameters on the high temperature oxidation and spallation behavior of HK30Nb will be discussed using high temperature exposures in dry air and flowing air + 10 % H2O at 700 and 800C for 5,000 h. Research sponsored by the U.S. Department of Energy, Vehicle and Technology Office. *Corresponding author e-mail: romedennem@ornl.gov