Method for controlling nodulation of carbon blind hearth roller

Abstract

The invention discloses a method for controlling nodulation of a carbon blind hearth roller. A transition steel coil does not enter into a high temperature furnace any longer when running speed of a high temperature furnace is more than or equal to 60m / min, surface of the high temperature furnace is seriously oxidized or the high temperature furnace runs for 15 times; oil content and iron content of alkaline washing alkaline liquor are controlled, and corresponding thermal compensation is carried out on rotating speed of a furnace roller according to temperature of strip steel, thus linear speed of the furnace roller is maintained to be consistent with the linear speed of the strip steel; alternate production of a high brand and a low brand is adopted, time for producing the high brand every time is not more than two days, and tension in the furnace is reduced when the high brand is produced; and the total air-fuel ratio of a non-oxidation furnace is controlled to be 0.92-0.98, a dew point of furnace gas at a carbon blind section is controlled to be 30-35 DEG C, hydrogen amount in a soaking pit furnace is controlled to be 16-20%, and furnace temperature of a furnace section corresponding to a nodulated carbon blind is reduced by 30 DEG C, thus nodulation generating conditions are destroyed. By adopting the method disclosed by the invention, almost no nodulation can be realized, thus service life of the carbon blind is prolonged by two months, halt frequency of a machine set and roller grinding frequency can be reduced, productivity of the machine set and surface quality of a steel plate are improved, consumption of energy source and medium is reduced, and production cost is reduced.

Description

technical field [0001] The invention belongs to the field of steel rolling technology, and in particular relates to a method for controlling the nodulation of carbon sleeve hearth rolls of a cold-rolled silicon steel continuous annealing unit. Background technique [0002] At present, most of the hearth rolls used in the continuous annealing production line of cold-rolled silicon steel are carbon sleeve hearth rolls. This is mainly because the carbon sleeve has good heat resistance and wear resistance, and the surface of the carbon sleeve is smooth and low in hardness. When the strip is in contact, it is not easy to cause adverse effects on the surface of the strip. [0003] However, because the carbon sleeve itself has a certain degree of tiny pores, the surface roughness of the carbon sleeve will gradually increase as time goes on under high temperature conditions, which provides conditions for the accumulation of iron powder and iron oxide powder, making iron Powder and ...

AI Technical Summary

Problems solved by technology

When the strip is running, the nodules will form scratch marks on the surface of the strip, which will affect the surface quality of the strip and force the unit to stop grinding the rollers. The grinding time is about 8 hours each time, which not only increases unnecessary energy and medium consumption, which reduces the service life of the online carbon hearth roller, increases the production cost, and directly affects the production capacity of the entire unit, reducing the unit operation rate

At the same time, it also seriously affects the lamination coefficient of the steel plate