Development of a portable device for thermoelectric power measurement: Application to the testing of duplex stainless steel components

The mechanical characteristics of cast duplex stainless steel components of the primary loop of pressurized water reactors may decrease as a consequen ce of thermal aging which causes spinodal decomposition of the ferrite Fe-C r-Ni solid solution. Previous studies led at EDF in collaboration with INSA have shown that thermoelectric power (TEP) is a very goad indicator of the aging state of the component. A new TEP measurement apparatus was develope d in order to perform measurement in industrial conditions on large steel c omponents. TEP measurements were made using this instrument and compared to those obtained using a conventional laboratory device. Finally, the portab le device was tested with success on a real elbow of a nuclear power plant.