In Situ Observation and Growth Kinetics of Bainite Laths in the Coarse-Grained Heat-Affected Zone of 2.25Cr-1Mo Heat-Resistant Steel During Simulated Welding

Austenite → bainite transformation has been documented in situ by confocal scanning laser microscope, and bainite growth kinetics has been quantified in the coarse-grained heat-affected zone of 2.25Cr-1Mo steel. Four typical nucleation sites of bainite laths have been identified. In addition, growth rate of nine distinctive bainite laths varies from 9 to 200 μm/s, depending on the degree of supercooling and nucleation sites of bainite laths.