The new features of Photothermal Prospecting as a Non- Destructive Testing technique applied to steel surface-treated alloys

This study sums up the authors recent works on steel Non-Destructive Testing and Evaluation achieved between 2000 and 2008. The main related items are the establishment of a first-order correlation between the thermal diffusivity and the Vickers hardness HV as a guide to set an NDT protocol to investigate steel strengthened surface performance. A special attention is confined toward carburized steel material, as the existence of any appropriated NDT photothermal technique is demonstrated to be unavoidably subjected to some restrictive conditions. The perspectives of the new features of this recent technique are discussed, with special concern with differently treated material like nitrured and nitrocarburazed quenched steel.