The influence of solidification rates and Cr equivalents on the formation of the ferrite was
studied by directional solidification in mod. (9-12)Cr-1Mo steels. It was found that the volume
fraction of ferrite increased as increasing Cr equivalent and solidification rate. The volume fraction of
the ferrite showed much higher at low solidification rates with the planar or cellular interface than that
at high solidification rates with the dendritic interface. The volume fraction of ferrite in solidification
microstructure showed much higher than that in extruded and heat-treated alloys. It depends on not
only solidification rate and Cr equivalent but also the solidification fraction. At low solidification
rates, there occurs segregation because the solid/liquid interface was planar or cellular, and it makes
composition change with solidification fractions. The formation of ferrite has been discussed with Cr
equivalent and solidification rate.
Directional Solidification Microstructure of a Ni-Based Superalloy: Influence of a Weak Transverse Magnetic Field
