Abstract
Heat affect zone in weldment of stainless steel was measured with the photothermal electrochemical (PE) detection scheme. "Heat affect zone" is the interface zone between steel plates generated in weldment. PE detection scheme was based on the accelerated chemical reaction caused by the absorption of laser light associated heat generation (photothermal phenomenon). For the specimens, a heat affect zone was prepared by arc welding method. The periodically modulated beam of an Ar^+ -ion laser is focused on the surface of a stainless steel plate, which is immersed in a 3.5% sodium chloride (NaCl) aqueous solution. A welded stainless steel plate was used both as a specimen and as an anode in electrochemical reaction. Nondestructive measurement of heat affect zone in weldment was carried out using the PE imaging with a X-Y scanning system controlled by a PC. PE amplitude images and signals were obtained at the similar spatial resolution. The PE amplitude signal intensity varied with the shape of heat affect zone in weldment.
