JP6172118B2 - Method for producing pickling material - Google Patents

Description

  The present invention relates to a method for producing a pickling material.

  Patent Document 1 states that “when a pickling material is produced in a pickling-rolling continuous line in which a plurality of rolling stands are arranged in series in a pickling tank, among the plurality of rolling stands, a rolling stand other than the final rolling stand is used. A method for producing a pickling material with good surface skin, characterized in that the work roll is retracted from the pass line of the pickling material and the pickling material is lightly rolled in a final rolling stand ”is described. Item 1]). According to this method, “the final rolling stand is used as a temper rolling stand, and the surface of the pickling material can be improved efficiently by temper rolling the pickling material online” ( [0004]).

Japanese Patent No. 4402680

  The inventor has studied a method for manufacturing a pickling material described in Patent Document 1. As a result, in the method of Patent Document 1, since the work rolls of the rolling stands other than the final rolling stand are retracted from the pass line, the conveyed steel strip (unwashed material) becomes unstable, especially when the speed is changed. It became clear that fluttering was likely to occur. If the steel strip (pickled material) flutters, it will be difficult to accurately measure the thickness with a thickness gauge, and for example, light rolling (temper rolling) with a uniform elongation rate will not be performed at the final rolling stand. In some cases, the mechanical properties of the pickling material obtained may be uneven in the longitudinal direction.

  This invention is made | formed in view of the above point, and it aims at providing the manufacturing method of the pickling material by which the flapping of the steel strip was suppressed.

  As a result of intensive studies to achieve the above object, the inventors of the present invention contacted one of the work rolls of a rolling stand other than the final rolling stand with a steel strip (unwashed material). As a result, it was found that the conveyance of the steel strip was stabilized and fluttering was suppressed, and the present invention was completed.

That is, the present invention provides the following (1) to (3).
(1) Pickling tank and a plurality of rolling stands including a final rolling stand are arranged in series on a steel strip pass line, and the rolling stand has a pair of work rolls sandwiching the pass line. A pickling material manufacturing method for producing a pickling material in a line, wherein the steel strip is pickled in the pickling tank to obtain a pickled material, and the final rolling stand includes And a temper rolling step for obtaining a pickled material by temper rolling the pickled material with a pair of the work rolls, and in the temper rolling step, the rolling stands other than the final rolling stand The manufacturing method of the pickling material which makes the said one work roll in the state which touched the material as it was pickled among a pair of said work rolls which has, and leaves | separates the other said work roll from the material as said pickling.
(2) The manufacturing method of the pickling material as described in said (1) whose distance which leaves the said work roll from the said pickling material is a distance more than the plate | board thickness of the said steel strip.
(3) In the temper rolling step, the pickling material according to (1) or (2), wherein a coolant is injected between the pickled material and the work roll in contact with the pickled material. Manufacturing method.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the pickling material by which the flapping of the steel strip was suppressed can be provided.

It is a schematic diagram which shows a pickling-rolling continuous line. It is a schematic diagram which expands and shows a part of pickling-rolling continuous line in the case of manufacturing a pickling material.

  Hereinafter, although one embodiment of the present invention is described based on a drawing, the present invention is not limited to the following embodiment.

  FIG. 1 is a schematic view showing a pickling-rolling continuous line. A pickling-rolling continuous line 1 shown in FIG. 1 includes a payoff reel 2 and a take-up reel 5 on which a coil of a steel strip S is hung. The steel strip S unwound from the payoff reel 2 is taken up again by the take-up reel 5 via the pickling tank 3 and the plurality of rolling stands 4. That is, on the pass line which is the conveyance path of the steel strip S, the pickling tank 3 and the plurality of rolling stands 4 are arranged in series in this order. In addition, in FIG. 1, although the five rolling stands 4 are shown in figure, the number of the rolling stands 4 is not limited to this. As another configuration, a plurality of tension meter rolls 6 that are in contact with the steel strip S from the lower surface side are arranged between the rolling stands 4, and a thickness gauge (not shown) is provided on the entry side and the exit side of the rolling stand 4. Is arranged.

  The pickling tank 3 contains an acid solution containing hydrochloric acid, for example. The steel strip S fed from the payoff reel 2 to the pickling tank 3 is pickled by the acid solution in the pickling tank 3 and becomes a pickled material.

Each rolling stand 4 has a pair of work rolls 41 (work roll 41a and work roll 41b) that are rotatably arranged at least at a position sandwiching the pass line of the steel strip S.
More specifically, the rolling stand 4 shown in FIG. 1 includes a pair of work rolls 41, a pair of backup rolls 42 that support the work rolls 41, and a pair of work rolls 41 and the backup rolls 42. This is a 6-roll mill composed of 6 intermediate rolls.
However, the type of the rolling stand 4 is not limited to the six-fold rolling mill, and may be a total of four quadruple rolling mills excluding the intermediate roll 43. In any type, since the configuration and operation thereof are not different from those conventionally known, detailed description is omitted.

A pair of work rolls 41 for rolling the steel strip S (as pickled material) are both arranged at positions in contact with the steel strip S (as pickled material) conveyed through the pass line. The work roll 41b located below the pass line is movably provided in a direction away from the steel strip S (unwashed material) (see FIG. 2).
Similar to the work roll 41b, the backup roll 42b and the intermediate roll 43b located on the lower side of the pass line are also provided to be movable in the same direction, and move according to the movement of the work roll 41b.

  In this embodiment, a load is applied to the steel strip S to be conveyed upward from the lower surface side by a mechanism or the like (not shown). For this reason, by fixing the position of the upper work roll 41a, the steel strip S loaded from the lower surface side is pressed from the upper surface side. Thereby, the fluttering of the steel strip S conveyed is suppressed so that it may mention later. However, it is not limited to this, and depending on the aspect of the pickling-rolling continuous line 1, the work roll 41a located on the upper side of the pass line can be moved in the direction away from the steel strip S, and the lower side The work roll 41b may be in contact with the steel strip S.

  Of the plurality (five in FIG. 1) of rolling stands 4, the final rolling stand 7 that is the rolling stand 4 located on the most downstream side is used for temper rolling when manufacturing pickling materials, as will be described later. Is done. The final rolling stand 7 has the same configuration as the other rolling stands 4.

In such a configuration, first, a case where a rolled material is manufactured in the pickling-rolling continuous line 1 will be described.
In the case of producing a rolled material, the steel strip S unwound from the payoff reel 2 is fed into the pickling tank 3 and pickled into a pickled material, and then passed through the rolling stand 4. At this time, the lower work roll 41b of the rolling stand 4 (including the final rolling stand 7) is brought into contact with the steel strip S without being separated from the steel strip S, and necessary pressure is applied. As a result, the pickled material is rolled by the rolling stand 4 to obtain a rolled material. The obtained rolled material is taken up by the take-up reel 5.

Next, based on FIG. 2, the case where a pickling material is manufactured will be described. FIG. 2 is an enlarged schematic view showing a part of a pickling-rolling continuous line in the case of producing a pickling material.
When manufacturing the pickling material, first, as shown in FIG. 2, the lower work roll 41 b in the four rolling stands 4 other than the final rolling stand 7 is separated from the steel strip S being conveyed. The upper work roll 41a maintains a position in contact with the steel strip S to be transported. Further, the pair of work rolls 41 of the final rolling stand 7 is maintained in a state where it is positioned at a position in contact with the steel strip S to be conveyed.

  In this state, the steel strip S unwound from the payoff reel 2 is fed into the pickling tank 3 and dipped in an acid solution to be pickled and used as a pickled material (pickling process). Thereafter, the pickled material is passed through a rolling stand 4 other than the final rolling stand 7, and light rolling, so-called temper rolling, is performed by the work roll 41 of the final rolling stand 7. As a result, the pickled material with roughened surface skin is temper-rolled to obtain a pickled material with improved surface skin (tempered rolling step). The pressure of temper rolling is appropriately adjusted according to the application. The obtained pickling material is taken up by the take-up reel 5.

  In this temper rolling process, when the pair of work rolls 41 of the rolling stand 4 other than the final rolling stand 7 are retracted from the pass line as in the method described in Patent Document 1, for example, the steel strip to be conveyed S is insufficiently supported, lowers the stability of conveyance, and flutters.

  On the other hand, in the present embodiment, the steel strip S is in a non-contact state with respect to the lower work roll 41b among the work rolls 41 of the rolling stand 4 other than the final rolling stand 7, The upper work roll 41a is conveyed in a contacted state (pressed state). Thus, since the steel strip S is transported in a state in which the insufficient support is eliminated, the transport is stabilized and fluttering is suppressed.

Moreover, in the method of patent document 1, when manufacturing a pickling material, the work roll 41 of rolling stands 4 other than the final rolling stand 7 is removed from the pickling-rolling continuous line 1 from a pass line. It is considered that the work roll 41 is attached again when the rolled material is produced by retracting. In such a method, the work of removing and attaching the work roll 41 is very complicated and the workability is poor.
However, in this embodiment, when manufacturing the pickling material, the work roll 41 is not required to be removed, and only one work roll 41b needs to be moved away from the steel strip S. And when manufacturing a rolling material, the work operation | work of attaching the work roll 41 is not required, and it is only necessary to move the separated work roll 41b in the direction approaching the steel strip S. Therefore, according to this embodiment, it is excellent in workability | operativity with respect to the method of patent document 1. FIG.

In the case of manufacturing the pickling material, the distance for separating the work roll 41b from the steel strip S (as-washed material) is preferably a distance equal to or greater than the thickness of the steel strip S, and more than twice the thickness of the steel strip S. Is more preferable. On the other hand, the upper limit is not particularly limited, and may be set as appropriate depending on the work roll return speed, the equipment configuration, and the like.
In addition, as for the plate | board thickness of the steel strip S, 1.6-3.3 mm is mentioned, for example.

Moreover, when manufacturing a pickling material, the work roll 41 (and the backup roll 42 and the intermediate roll 43) which the rolling stands 4 other than the final rolling stand 7 have are rotated in synchronization with the conveyance speed of the steel strip S. Is preferred.
In particular, the lower work roll 41b that is separated from the steel strip S and does not contribute to conveyance, and the backup roll 42b and the intermediate roll 43b also continue to rotate without being stopped, so that the backup roll 42b and the like are locally provided. It is suppressed that hardness nonuniformity arises by being cooled. When unevenness in hardness occurs, the plate thickness variation of the steel strip S is promoted, and it is preferable that this is suppressed.

In the rolling stands 4 other than the final rolling stand 7, one of the pair of work rolls 41 is separated from the steel strip S, so that the steel strip S passes through without being rolled.
However, since the other work roll 41a is in contact with the steel strip S (unwashed material), an unillustrated jet is provided between the steel strip S (unwashed material) and the work roll 41a in contact with the steel strip S (unwashed material). It is preferable to inject the coolant (rolling oil) using the means. Thereby, the damage of steel strip S (as-washed material) by contact with work roll 41a is controlled.

  Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to these.

<Example 1>
Pickling material was manufactured from the steel strip S (plate thickness: 1.63 mm, plate width: 1000 mm) which is a low carbon steel, using the pickling-rolling continuous line 1 described based on FIG. 1 and FIG. . At this time, first, the lower work roll 41b in the four rolling stands 4 other than the final rolling stand 7 was separated from the steel strip S to be conveyed by 10 mm.
In this state, the steel strip S is unwound from the payoff reel 2 and sent to the pickling tank 3 at a line speed of 200 m / min, and an acid solution (temperature: 85 to 95 ° C., stored in the pickling tank 3). Pickling was performed by immersing in HCl concentration: 4 to 10% by mass) for 25 seconds. Next, the steel strip S pickled in the pickling tank 2 (as pickled material) is in contact with only the upper work roll 41a in the four rolling stands 4 other than the final rolling stand 7 (lower work). In a non-contact state with the roll 41b), it is transported to the final rolling stand 7 and subjected to temper rolling at a rolling reduction rate of 0.9% in the final rolling stand 7 to obtain a pickling material with improved surface skin. Thereafter, the film was wound up by the take-up reel 5.

<Comparative Example 1>
The pickling material is manufactured in the same manner as in Example 1 except that the work roll 41, the backup roll 42, and the intermediate roll 43 of the four rolling stands 4 other than the final rolling stand 7 are removed and retracted from the pass line. did.

<Evaluation>
In both Example 1 and Comparative Example 1, a plate thickness gauge (not shown) was installed on the exit side of the final rolling stand 7, and the plate thickness of the pickling material taken up by the take-up reel 5 was measured. As a result, in Example 1, the stretch rate of the pickling material was obtained uniformly in the longitudinal direction, whereas in Comparative Example 1, the stretch rate was non-uniform in the longitudinal direction.
In Comparative Example 1, since the pair of work rolls 41 of the rolling stand 4 are retracted, the conveyance of the steel strip S (unwashed material) leading to the final rolling stand 7 becomes unstable, and uniform in the final rolling stand 7. This is probably because the material was not temper rolled.
On the other hand, in Example 1, it is considered that the steel strip S (unwashed material) was stably conveyed up to the final rolling stand 7 and uniformly tempered and rolled at the final rolling stand 7.

1: Pickling-rolling continuous line 2: Payoff reel 3: Pickling tank 4: Rolling stand 41 (41a, 41b): Work roll 42 (42a, 42b): Backup roll 43 (43a, 43b): Intermediate roll 5: Take-up reel 6: Tension meter roll 7: Final rolling stand

Claims (3)

A pickling tank and a plurality of rolling stands including a final rolling stand are arranged in series on a steel strip pass line, and the rolling stand has an acid pickling-rolling continuous line having a pair of work rolls sandwiching the pass line. A method for manufacturing a pickling material, which manufactures a cleaning material,
In the pickling tank, the steel strip is pickled to obtain a raw material as pickled, a pickling step,
A pair of the work rolls of the final rolling stand, temper-rolling the material as it is pickled to obtain a pickled material, and a temper rolling step,
In the temper rolling step, among the pair of work rolls of the rolling stand other than the final rolling stand, one of the work rolls is in contact with the pickled material, and the other work roll is The manufacturing method of the pickling material which makes it leave from a material with pickling.   The manufacturing method of the pickling material of Claim 1 whose distance which makes the said work roll space apart from the said pickling material is a distance more than the plate | board thickness of the said steel strip.   The manufacturing method of the pickling material of Claim 1 or 2 which sprays a coolant between the said pickling material and the said work roll which touches the said pickling material in the said temper rolling process.

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