PROCEDURE FOR ANNEALING ROLLS OF AUTOMOBILE-BODY SHEET STEEL IN BELL FURNACES Russian patent published in 2011 - IPC C21D1/26 C21D1/84 C21D9/46 F27B11/00 F27D9/00 

FIELD: metallurgy.

SUBSTANCE: procedure consists in heating rolls in bell furnaces to temperature of re-crystallisation annealing specified by bench thermocouple with successive conditioning. Rolls are conditioned under the bell at extinguished burners and cooled. Temperature of annealing under the bell of the furnace is set as 770-790°C by a zone thermocouple. Rolls are cooled to temperature 640°C by the bench thermocouple at rate 10-15°C/hour. Further, rolls are cooled during three hours to temperature 600°C by the bench thermocouple. Finally, rolls are conditioned under the bell with extinguished burners during five hours.

EFFECT: upgraded quality of strip surface at absence of strip defects - slide line, fracture - due to reduced impurity of strip during cold rolling on textured rollers and due to avoiding coils sticking during annealing.

1 dwg, 1 ex