INTERSTITIAL FREE STEELS

摘要

The strength of interstitial free steels is increased by up to 100 % and the ductile to brittle transition temperature is decreased by up to 100 DEG C by warm finish rolling in the single phase ferrite region below Arl to effect ferrite dynamic recrystallization of the steel microstructure to a ferrite structure of grain size having a grain size of up to 5 mu m, and especially an ultra fine grain size of 1 to 2 mu m; the method may be employed in various hot working methods including strip and rod mills, planetary hot rolling and extrusion.