|About this Abstract
||Materials Science & Technology 2020
||Environmentally Assisted Cracking: Theory and Practice
||The Relationship between Post-build Stress-relief Heat Treatment and the Hydrogen Embrittlement Susceptibility of Additively Manufactured IN625
||Mark R. Stoudt, Richard Ricker, Maureen Williams, Fan Zhang
|On-Site Speaker (Planned)
||Mark R. Stoudt
The combination of strength, corrosion resistance, and excellent weldability makes IN625 an attractive alloy for additive manufacturing (AM) applications, but the build process generates large compositional and residual stress gradients. Appropriate post-build heat treatments are necessary to relieve stress and produce uniform microstructures and properties; however, stress-relief also promotes the growth of carbides and intermetallic phases. Large precipitates alter the local electrochemical conditions, while the modulus mismatch with the surrounding matrix can reduce the crack propagation resistance. The question is whether these secondary phases increase the susceptibility of IN625 to hydrogen embrittlement. Slow strain rate tensile tests were performed in an acidified chloride solution using wrought and AM samples, with and without heat treatment, and under free corrosion and potentiostatic conditions that controlled the hydrogen fugacity. The experimental protocol, and the results from microstructural and fractographic analyses of the AM materials will be compared to the wrought IN625 and discussed.