09.05.2020 | Communication | Ausgabe 7/2020
In Situ Observation of Phase Transformations in the Coarse-Grained Heat-Affected Zone of P91 Heat-Resistant Steel During Simulated Welding Process
- Zeitschrift:
- Metallurgical and Materials Transactions A > Ausgabe 7/2020
Wichtige Hinweise
Manuscript submitted on March 9, 2020.
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Abstract
The solid-state phase transformation in the coarse-grained heat-affected zone of P91 steel under simulated welding thermal cycle has been investigated in situ by confocal scanning laser microscope. It is found that γ-austenite initiates from the triple point of δ-ferrite grain boundaries (GBs), then at ordinary δ-GBs, and eventually from grain interiors. Upon further cooling, martensite laths are observed to nucleate and growth instantaneously, with the growth rate being estimated ranging from 175 to 454 μm/s.
