C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
C21D8/005—Modifying the physical properties by deformation combined with, or followed by, heat treatment of ferrous alloys