Microstructural characterization of simulated and actual constituent regions of P91 steel weldment

Abstract

In the present study simulated and the actual microstructures of the coarse grain, fine grain and intercritical heat-affected zones of P91 steel weldment are characterized using electron backscattered diffraction (EBSD) technique. Both the simulated and actual heat-affected zone (HAZ) microstructures showed profound substructural recovery after post-weld heat treatment/tempering. The subgrain size distributions between the simulated and the actual HAZs are comparable. The actual HAZ microstructures exhibited greater low angle grain boundaries and local strain distributions compared to the simulated HAZ microstructures due to the complex microstructural geometry of the actual weldment. The similarity in the variations of grain size, precipitate size and hardness of the simulated and actual HAZs validates the simulation of HAZ microstructures through furnace heat treatment.

Keywords:

• P91 steel
• simulated HAZ
• microstructure
• EBSD
• hardness
• yield strength

Acknowledgements

The paper is dedicated to Late Dr. Arun Kumar Bhaduri, Former Director, Indira Gandhi Centre for Atomic Research, Kalpakkam for guiding the first author’s PhD work.

Disclosure statement

No potential conflict of interest was reported by the author(s).