The Characterization of Soft Fine-Grained Heat-Affected Zones in P91 Weldments under Creep Exposure Conditions

The martensitic 10CrMoVNb 91 (P91) steel welded joint is subjected to reaustenitizing-based post-weld heating, referred to as post-weld normalizing and tempering (PWNT). The various zones of P91 weldments in PWNT treatment and after creep exposure at 620 degrees C for 150 MPa are studied. The evolution of intermetallic Laves phase in the various zones of P91 weldments is observed after the creep rupture tests. The evolution of Laves phase is characterized using field-emission scanning electron microscopy (FESEM) with energy-dispersive X-ray spectroscopy.