MICROSTRUCTURE AND PROPERTIES OF DISSIMILAR WELDED JOINT BETWEEN P91

This paper presents the results of investigations of a dissimilar welded joint made between X10CrMoVNb9-1 (P91) martensitic steel and TP347HFG austenitic steel. The welded joint material was taken from a primary steam super-heater coil operated at maximum working temperature of approx. 540°C for more than 105 000 hours. Destructive testing and metallographic tests were carried out for the welded joint material to determine the impact of long-term service on the properties of the joint. Microstructure of the welded joint was observed using a optical microscope (OM) and scanning electron microscope (SEM). The destructive testing included: impact test, static tensile test and hardness measurement