METHOD OF HEAT TREATMENT OF ROLLED STOCK Russian patent published in 2004 - IPC

FIELD: ferrous metallurgy; heat treatment of reinforcing-bar steel by use of rolling heat; manufacture of high-strength reinforcing bars. SUBSTANCE: blank is heated and rolled and feed is subjected to heat treatment by heating to recrystallization temperature followed by cyclic cooling of surface. Number of cycles of cyclic cooling is two: duration of first cycle is (0,017-0,019)D_rmm s and duration of second cycle is (0,05-0,06)D_rmm s; surface is heated between cycles during 0.5-0.6 s; then, surface is finally heated during total time of heat treatment of rolled stock, i.e. during 7.5-8.5 s, after which final cooling in air is performed. EFFECT: improved strength characteristics; enhanced corrosion resistance to cracking. 2 tbl, 1 ex