Larson–Miller correlation for the effect of thermal ageing on the yield strength of a cold worked 15Cr–15Ni–Ti modified austenitic stainless steel

For 20% cold worked 15Cr–15Ni–Ti modified austenitic stainless steel (Alloy D9), the Larson–Miller parameter can be used to describe the effects of prior thermal exposures to different time–temperature combinations on the 0.2% yield stress σYS, ultimate strength and total elongation in subsequent tensile tests at 300, 723 and 923 K. A single master plot for all the tensile test temperatures was obtained by plotting the Larson–Miller parameter against the ratio SYS=(σYS of thermally aged material)/(σYS of un-aged material) at identical tensile testing temperature.