The invention relates to the technical field of steel rolling in the steel
metallurgy technology and relates to a method for improving the production efficiency of Q345B
hot rolled narrow
strip steel.The method includes the following steps that firstly, molten iron pretreatment is conducted; secondly, converter
smelting is conducted, wherein the converter steel putting time is not shorter than 2min, when
molten steel is discharged by one fifth,
calcium silicon,
silicon carbide, silicomanganese,
vanadium nitrogen and
ferroniobium are added in a batched manner for
deoxygenation alloying, a carburant is added for increasing carbon, and adding is completed when molten iron is discharged by three fourths; the temperature of a steel
ladle is larger than or equal to 700 DEG C, 3 kg / t to 6 kg / tof modification agents are added to the steel
ladle bottom before tapping, and then online baking of the steel
ladle is conducted; thirdly, bottom
argon blowing stirring is conducted in the whole process,
argon blowing is conducted for 13 min to 15 min totally, the
argon flow is controlled to be 200 L / min to 300 L / min in 10 min before argon blowing, and the
argon flow is controlled to be 50 L / minto 80 L / min before departing; fourthly,
continuous casting is conducted, protective
casting is conducted in the whole process, the superheat degree of
tundish molten steel is controlled to range from20 DEG C to 30 DEG C; and fifthly, hot rolling is conducted. By means of the method, an
alloy replacing method is used for reducing the adding amount of
alloy materials, the converter tapping temperature can be reduced, and therefore the purpose of improving the production efficiency and capacity is achieved.