ANNEALING METHOD OF COLD-ROLLED COILS MADE OF LOW-CARBON STEEL Russian patent published in 2009 - IPC C21D8/04 C21D1/26 C21D9/663 

FIELD: metallurgy.

SUBSTANCE: invention concerns metallurgy field and can be used for heat processing of cold-rolled coils made of low-carbon steel, stabilised by aluminium, in bell muffle furnace with gas heating and hydrogenous protective atmosphere. For reducing of fuel consumption and improvement of cold-rolled coils method includes many-stage heating of coils till annealing temperature and further cooling with regulated speeds. Heating from the temperature 180-220°C till the temperature 480-520°C is implemented with speed 65-85°C/h, reheating is implemented till the temperature 580-620°C with speed 4-11°C/ h, after what heating till annealing temperature 700-720°C is implemented with speed 20-50°C/h. Furthermore coils are kept at annealing temperature not less than 13 h, after what they are cooled at first with speed 10-30°C/h till the temperature 650-690°C, and then with speed 30-60°C/h till the temperature 460-480°C.

EFFECT: reduction of fuel consumption improvement of cold-rolled coils.

2 cl, 1 ex, 1 tbl