New steel coupons hosting residual stresses for steel health monitoring calibration

New steel coupons hosting different residual stress amplitudes are proposed in this paper, that are able to calibrate magnetic sensors for residual stress monitoring. The new stress coupons can be developed by local Joule heating of the steel grade up to 400 °C at one end of it, monitoring the temperature elevation at the other end. As soon as the temperature at the other end increases 1 ° to 10 °, a consequent quenching in cold or iced water, oil and liquid nitrogen, thus transforming the temperature gradient to stress gradient. The 400 ° temperature limit was experimentally selected to avoid any type of phase transformation and geometrical deformation of the steel grade sample. This method of developing stress coupons is much better than the current method based on welded samples, allowing for low uncertainty in inter-laboratory tests, that permitting the preparation of a corresponding standard.