METHOD OF HEATING STEEL INGOTS IN CONTINUOUS FURNACES Russian patent published in 2002 - IPC

FIELD: metallurgy, particularly, heating of steel ingots containing chromium and nickel in continuous furnaces. SUBSTANCE: used for heating of ingots is gas mixture with total calorific value of 4300-5100 kcal/cu.m. Ingots containing total amount of nickel and chromium within 1.02-10.0 mas.% are heated with use of mixture of coke, natural and blast-furnace gases with volume ratio of mixture components within 0.1-40.0, 43.3-48.5, and 16.7-51.4, respectively. With content of total amount of nickel and chromium within 0.02-1.0 mas.%, ingots are heated with use of mixture of natural and blast-furnace gases with volume ratio of components of 48.5-59.8 and 40.2-51.5, respectively. EFFECT: reduced furnace loss of metal in heating, decreased amount of defects in the form of rolled-in scale and rolling skin on strip after ingot hot rolling. 2 tbl