HEAT TREATMENT METHOD FOR ROLLED PRODUCTS Russian patent published in 1994 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: method presented ensures reaching engineering result, that is achieving plastic and viscous properties of rolled products of usual medium-carbon steels at negative temperature at the expense of heat treatment technology. The heat treatment allows one to achieve structure of tempered sorbite in the surface layer and ferrite of high dispersion with inclusions of sorbite in the center of the workpiece. Heat treatment method includes cyclic cooling with surface undercooling below M_h point with a number of cycles equal two of (0.015 - 0.045)D s duration, where D is rod diameter; intermediate thawing out the surface during 0.7 - 2.5 s, and final thawing out the surface during 4.0 - 7.5 s up to M_h point, but below A_c1 point, and final cooling. EFFECT: production of rod reinforcements of high strength. 1 tbl