Properties of T/P92 weld metals for ultra super critical (USC) power plant

Abstract

The introduction of new power generation technologies, such as ultra super critical (USC) plant, has resulted in the development and application of a series of advanced Cr-Mo creep resistant steels. Among these new alloys, T/P92 steel has creep strength 25%-30% higher than the currently widely used T/P91 steel and it has become one of the major alloys for the construction of USC plant. In order to obtain a good understanding of the microstructural characteristics and properties of the T/P92 weld metals, investigation was conducted to welds from SMAW, SAW and FCAW processes using matching filler metals. The important phase transformation temperatures, Ac1, Ms and Mf, were measured. The mechanical properties at ambient temperature and creep properties of the weld metals were evaluated. Procedural factors that influence the performance of T/P92 weld metals were discussed and recommendations for suitable practical welding and post-weld heat treatment procedures were presented.