A toughness study of the weld heat-affected zone of a 9Cr–1Mo steel

The toughness of the weld heat-affected zone microstructures of a 9Cr–1Mo steel has been studied with simulated samples. From the Charpy impact test results, the highest toughness in terms of the highest upper-shelf energy and the lowest ductile-to-brittle transition temperature have been observed in the intercritical region. The lowest toughness was observed in the coarse prior-austenitic grained martensite region adjacent to the fusion line. The microstructural effect on the toughness has also been discussed.