A start-up method for annealing furnace to prevent warping

Abstract

The invention discloses an anti-deflection start-up method of an annealing furnace. The anti-deflection start-up method of the annealing furnace comprises the following steps: acquiring the actual retention time of belt steel in the annealing furnace and then comparing the actual retention time with a preset time threshold value; and if the actual retention time is less than or equal to the presettime threshold value, performing start-up in the annealing furnace at once after unplanned shutdown. In order to avoid generation of "deflection" defect on the surface of the belt steel caused by thefact that the temperature difference of the belt steel and a furnace roller is increased when the temperature of the belt steel is reduced continuously, a furnace area adopts "rapid speed-up" operation at the moment until the speed of the belt steel is more than the minimum safe operation speed. If the actual retention time is more than the preset time threshold value, start-up can be conducted after the temperature is reduced, the furnace area adopts "stepped speed-up" until the belt steel which stays in a heat area in the furnace completely deviates from a heating section and a soaking section, "stepped speed-up" is to enable the temperature of the belt steel and the temperature of the furnace roller to tend to be consistent as much as possible, and occurrence of the belt breaking accident in the furnace caused by serious deflection during start-up of materials liable to deflect is avoided.

Description

technical field [0001] The invention relates to the technical field of annealing, in particular to a start-up method for preventing warpage of an annealing furnace. Background technique [0002] In the annealing process, the vertical annealing furnace is mainly composed of a preheating section, a heating section, a soaking section, a slow cooling section, a fast cooling section, an overaging section, and a final cooling section. The heating section and the soaking section are heated by radiation. The strip is heated to the temperature 580-840°C required for annealing. Once the annealing furnace is shut down, the heating section and the soaking section stop burning at this time. Since the thermal inertia of the strip is much smaller than that of the furnace roll, the rate of decrease in the temperature of the strip is much greater than that of the furnace roll. At this time, if the start-up operation is carried out, for materials that are easy to warp, hot warp will easily o...

AI Technical Summary

Problems solved by technology

At this time, if the start-up operation is carried out, for materials that are easy to warp, hot warp will easily occur in the heating section, that is, strip steel wrinkle deformation

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