METHOD OF HEAT TREATMENT OF COLD ROLLED PRODUCTS MADE OF LOW-CARBON STEEL Russian patent published in 2017 - IPC C21D9/663 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: simple heating is carried out in a protective atmosphere from a temperature of 200-220°C to the annealing temperature T_ann=550+3100°C, where 550 and 3100 are empirical factors obtained experimentally, C is the fraction of carbon in steel, wt %, holding time in the furnace of t=0.18×m+10, where 0.18 and 10 are empirical factors obtained experimentally, m is the average mass of a roll in the load, t, heating stop, heating hood removal, holding under the cooling hood for 15-30 minutes, after which accelerated cooling under the muffle at a rate of 20-30°C/h for 14-22 hours. In addition, accelerated cooling under the muffle is carried out from a temperature of not more than 530°C, and unpacking is performed at a temperature of not more than 90°C.

EFFECT: increase in the performance of hood furnaces and a reduction in the consumption of energy resources while guaranteeing the required complex of mechanical properties of cold-rolled strip, a significant reduction in the sorting for the welding sticker patches.

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