“…However, it is slightly sensitive to the microstructure effects (grains size [1], [2], [3], carbon rate [4], [5], texture [6], [7], [8], [9], and structure [10], [11], [12]) and to the operating conditions (temperature [13], [14], coupling [15], [16], etc.). The ultrasonic estimation of the residual stresses requires separation between the microstructure and the acoustoelastic effects.…”