JPH03158483A - Continuous annealing and pickling equipment for cold rolled stainless steel strip - Google Patents

Abstract

PURPOSE:To prevent the generation of flaws on the surface of an annealed stainless steel strip by providing a brush roll stand between a cooling zone and a center bridle at the time of annealing the cold rolled stainless steel strip with the continuous annealing and pickling equipment consisting of an annealing furnace, cooling zone, center bridle and pickling tank. CONSTITUTION:The cold rolled stainless steel strip 1 is passed through the annealing furnace 2 and is thereby annealed; thereafter, the steel strip is passed through the cooling zone 3, by which the steel strip is rapidly cooled. The scale on the surfaces of the stainless steel strip 1 is polished away by abrasive grain brush rolls 7 in the brush roll stand 5. The stainless steel strip 1 subjected to the surface cleaning is introduced through the center bridle 9 into the pickling tank 10 where the scale remaining on the surfaces is dissolved. The annealed stainless steel strip having the excellent surface condition is thus stably produced. Since the hardly peelable scale on the surface of the stainless steel strip is removed by the brushing rolls 7, the sticking of the scale to the center bridle rolls 9 and the flawing of the surface of the succeeding stainless steel strip are prevented.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to continuous annealing and pickling equipment for cold-rolled stainless steel strips that can improve product quality and yield of cold-rolled stainless steel strips. It is.

<Prior Art> Generally, continuous annealing and pickling equipment for cold-rolled stainless steel strips includes an annealing furnace, a cooling zone, and a pickling tank.

A horizontal catenary furnace is often used as the annealing furnace, and annealing is performed in an oxidizing combustion atmosphere using a direct flame. The cooling zone cools the cold-rolled stainless steel strip annealed in the annealing furnace by using gas jet cooling or water cooling such as mist. The pickling section is composed of a combination of molten salt/neutral salt electrolysis, nitric-fluoric acid/nitric acid electrolysis, etc.

By the way, in recent years, continuous annealing and pickling equipment for cold-rolled stainless steel strips has become longer and longer as higher productivity is required. , the tension of the annealing furnace, cooling zone and pickling section is now controlled separately.

This example is shown in FIG. 3, where 1 is a stainless steel strip, 2 is an annealing furnace, 3 is a cooling zone, 9 is a center bridle, 10 is a pickling tank, and 4 is a support roll.

<Problem to be solved by the invention> In the continuous annealing and pickling equipment for cold-rolled stainless steel strips described above, when there is a change in operating conditions due to a change in steel type or a change in copper strip size, it is necessary to use a threading material (dummy material). It operates by inserting it between steel strips.

Because this threaded material is reused many times, its surface is roughened by acid.When this threaded material is passed through, the surface of the threaded material has no luster and a high heat transfer coefficient. Due to factors such as unstable conditions inside the furnace, a large amount of scale is generated on the surface of the threaded material at the furnace exit. This scale is very easy to peel off, and in the past, this scale adhered and accumulated on the center bridle at the entrance of the pickling tank, causing scratches on the succeeding stainless steel strip (product). was.

An object of the present invention is to provide continuous annealing and pickling equipment for cold-rolled stainless steel strips that solves these problems.

<Means for Solving the Problems> The present invention provides continuous annealing and pickling equipment for cold-rolled stainless steel strips in which an annealing furnace, a cooling zone, a center bridle, and a pickling tank are sequentially arranged. To,
This is a continuous annealing and pickling equipment for cold-rolled stainless steel strips, which is characterized by being equipped with a brush roll stand for inserting abrasive grains.

<Function> In order to prevent scale from adhering to the center bridle, it is effective to make the surface of the threading material to be used beautiful. One possible way to do this is to reuse the threaded material and polish the surface with a coil grinder before reusing it.However, this method requires surface polishing costs and requires a large number of threaded material to be kept. There are other problems.

For this reason, the present inventors considered removing the scale generated on the threaded material before it enters the center bridle.

In other words, the present invention was completed after considering using some means to remove a large amount of peelable scale on the surface of the threaded material that had come out of the cooling zone.

In the present invention, a brush roll stand is installed between the cooling zone and the center bridle, and the scale that is easily peeled off from the threaded material generated during the annealing and cooling process is removed by polishing the surface with an abrasive brush.

The low-grain brush was selected because the required amount of polishing of the surface of the threading material to avoid staining the center bridle was about 0.5 am.

<Example> An embodiment of the present invention will be described based on a concave surface.

FIG. 1 is an explanatory diagram schematically showing the equipment of the present invention.

In FIG. 1, a stainless steel strip 1 is subjected to a predetermined heat treatment in an annealing furnace 2 and then rapidly cooled in a cooling zone 3. 4a,
4b are support rolls for the annealing furnace 2 and the cooling zone 3, respectively.

After leaving the cooling zone, the threaded material is polished by a brush roll 7 containing abrasive grains of a brush stand 5, and scale on the surface can be easily removed. Cooling) Between the IF3Σ brush stands 5, it is more effective to increase the tension in the stands with the pinch rolls 6 in order to increase the cleaning ability.

After being treated in this way, the threaded material enters the center bridle 9, so that scale adhesion to the surface of the center bridle 9 is drastically reduced. 10 is a pickling tank.

In addition to being used for threading material, this brush roll 7 can also be used as an aid for descaling by lowering the reduction blade and using it under conditions where no scratches (grinding marks after polishing with an abrasive brush) occur. can.

Next, specific examples of the present invention will be described.

In the equipment shown in FIG. 1, the annealing furnace 2 had a furnace length of 45 m, and asbestos was used for the support roll 4a. Cooling zone 3 is 15
Carbon was used for the m1 support roll 4b. For the brush roll 7, a nylon base containing SiC abrasive grains was used. The diameter of the brush is 1.2+nmφ, and the motor of the brush stand 5 is 454 mm. The center bridle 9 is driven by three pieces, the roll surface material is neoprene, and the roll diameter is 1200 mmφ.

The dirt on the center bridle roll in this equipment is shown in Figure 2 (1). A comparison is shown based on the case without using.

Furthermore, FIG. 3 (2) shows the incidence of flaws caused by dirt on the center bridle roll depending on the presence or absence of a brush stand.

From Figure 2 (1) and (2), when the surface of the threaded material is polished with a brush stand, the amount of dirt on the surface of the center bridle roll is reduced to 1/3, and the occurrence of scratches due to dirt on the center bridle roll is reduced to 1/4. It can be seen that it has decreased to

<Effects of the Invention> As explained above, the following effects can be obtained by the present invention.

■ Scale adhesion to the center bridle roll is significantly reduced compared to conventional rolls, and scratches caused by dirt are also significantly reduced.

■ There is no need to clean the center bridle when a flaw occurs, improving line operation efficiency and eliminating the need to clean the bridle, improving safety.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram schematically showing an embodiment of the present invention, Fig. 2 is a graph showing the concrete implementation results of the present invention in comparison with the case using conventional equipment, and the figure shows the conventional equipment. FIG. 1...Stainless steel copper band, 2...Annealing furnace, 3...Cooling zone, 4.4a, 4b=-support roll, 5...Brush stand, 6...Pinch roll, 7... Brush roll, 8... Ringer roll, 9... Center bridle, 10... Pickling tank.

Claims (1)

[Claims] In a continuous annealing and pickling facility for cold-rolled stainless steel strip in which an annealing furnace, a cooling zone, a center bridle, and a pickling tank are sequentially arranged, a brush roll stand containing abrasive grains is provided between the cooling zone and the center bridle. Continuous annealing and pickling equipment for cold-rolled stainless steel strips.