Effect of Thermomechanical Treatment on X-Ray Elastic Constants and Residual Stresses in HSLA-100 Steel

The thermomechanical treatment of HSLA-100 steel is undertaken to upgrade its properties. The plastic deformation in our study was done below and above the recrystallization temperature of austenite, as well in the two-phase ( + ) region, followed by accelerated cooling. The plates were subsequently aged at two temperatures. The optical microstructures and hardness were done, and the effect of finish rolling temperature was established. The residual stress, X-ray elastic constants (XEC) and relative peak intensity were determined using X-ray diffraction. The effect of aging temperature on hardness, residual stress, Young''s modulus, and Poisson''s ratio was established. The residual stress values calculated using the XEC values obtained were found to be on the lower side compared to stress values using bulk elastic constants. The maximum difference in stress values is about 27%, which justifies the determination and use of XEC to obtain absolute values of stress.