FORMATION OF PEARLITIC BANDED STRUCTURES IN FERRITIC-PEARLITIC STEELS

The conditions for ferrite and pearlite banding in strip and plate made of structural steels were investigated. Factors found to influence the formation of banded structures were the cooling rate during the gamma/alpha-transformation, the former austenite grain size, and the work-hardened condition of the former austenite. Analyses with the aid of an electron beam microprobe made it possible to demonstrate that the carbon-rich bands correspond locally with banded manganese enrichments, yet that they do not form before the course of the gamma/alpha-transformation as a result ot secondary segregation. It was possible to explain the mechanism of action of the influencing factors on the basis of this model.