Abstract
In this work, the combined effects of strain rate and internal hydrogen (from gaseous precharging) on the tensile properties of 304L austenitic stainless steel in both annealed and forged conditions are characterized. Due to its high corrosion resistance, strength, and formability, 304L has a wide variety of applications, including pressure vessels, valves, and other manifold components. While both the strain rate sensitivity and hydrogen effects on 304L have been reported in the past, the combined influence of internal hydrogen and strain rate on the tensile flow curves has not been studied. To better understand these effects, uniaxial tensile tests were performed at strain rates varying between approximately 10−2 and 10−5 per second both with and without internal hydrogen. The combined influence of strain rate and internal hydrogen on the tensile flow curves and strain-induced martensite are reported and discussed. It was found that the 0.2% offset yield stress increased with increasing strain rate for both conditions (with and without internal hydrogen), at nearly a constant rate per decade. Additionally, for the annealed material, the relative change in stress was shown to be approximately equivalent (an increase of 45 MPa) when comparing the fastest strain rate (10−2 /s) with the slowest rate (10−5 /s) for both with and without internal hydrogen. The influence of internal hydrogen on rate dependent parameters are also discussed for the forged 304L.
