COIL ANNEALING METHOD IN HOOD FURNACE Russian patent published in 2007 - IPC C21D9/663 C21D1/26 C21D1/74 

FIELD: heat treatment of ferrous and non-ferrous metals, possibly production of cold rolled strip steel for forming complex-configuration parts.

SUBSTANCE: method comprises steps of heating coils with rolling emulsion applied on strip surface till temperature 690 - 710°C; slowing temperature rise in temperature range that is by 50 -150°C lower than temperature of recrystallization starting of annealed metal in hydrogen medium at flow rate 3.5 - 4.5 m³/h; increasing flow rate by 6 - 7 times for period of slowing heating consisting of 0.17 -0.23 of heating period; cooling coils under heating hood after termination of their heating for time period consisting of 0.33 - 1.0 of slowing period of temperature rise at heating; then dismounting hood and cooling coils under muffle till temperature 130 - 150°C in zone of the most slow cooling of coil stack.

EFFECT: improved quality of products, increased yield of complex-elongation strip and strip with first group of surface finishing, energy saving.

6 tbl, 1 dwg, 1 ex