Previous measurements on ENGIN-X (RB1710155) performed on samples with different residual stress states after cold expansion gave good correlations between numerical and experimental results in the initial state after cold expansion up to 2mm from the surface. However, measurements closer to the surface could not be performed due to the gage volume set up and no clear trend concerning stress relaxation after thermo-mechanical treatments could be observed compared to the reference state. This experiment aims at feeling the gap of the previous experiment with diffraction measurements closer to the surface in the initial state (reduction of the gage volume) and with measurements on samples with appropriate thermo-mechanical treatments (calibrated using FE simulation) in order to finalise the characterisation of residual stresses after cold expansion and validate the numerical modelling