Abstract
The role of aging conditions vis-a-vis the precipitate state on the hydrogen embrittlement behavior of IN 718 has been studied. Slow strain rate tests showed that the overaged condition was most susceptible to hydrogen embrittlement followed by the peak-aged and solution-annealed conditions. Hydrogen permeation studies carried out using Devanathan–Stachurski cell showed that the hydrogen diffusivity values varied in the order: overaged condition < solution-annealed < peak-aged conditions. The hydrogen trapping due to increased δ precipitates was found to be responsible for increase in the degree of susceptibility towards hydrogen embrittlement between the aging conditions. These precipitates when aligned along the grain boundaries for peak-aged condition promoted hydrogen diffusion, whereas their alignment across the grain boundaries in case of overaged condition hindered the grain boundary diffusion process. The path for hydrogen migration became tortuous which retarded hydrogen migration in the alloy and hence the hydrogen embrittlement susceptibility.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
