FIELD: metallurgy.
SUBSTANCE: dismantled main 540-1420 mm diameter pipes are used for ring blanks are cut. C-like intermediate blank is cut from said ring workpiece for it to be cold-straightened at stretcher. Then, rectangular strip produced is heated in duct heater at the rate of 80-120°C/s to ≤950°C. Then, the strip is rolled at rolling end temperature of 870-920°C. Produced profiled iron is quickly cooled to 340-470°C. Now, rolled stock is air cooled at the rate of 5-10°C/min. Besides, strip blank is cut from pipe in lengthwise direction, its length Lp neing defined from the expression: Lp=Lr/λΣ+Lcr, where Lr is rolled stock preset length, 6.0-11.7 m, λΣ is total drawing at rolling, 1.5-3.5, Lcr is end crops length, 0.15-0.35 m.
EFFECT: expanded performances.
5 cl, 4 dwg
