JPH09216008A - Press mechanism of hot steel joining machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press mechanism for suppressing variation of rolling load as smaller as possible at the time of joining steels having different thicknesses. SOLUTION: After facing a preceding thin steel 31 to the succeeding thick steel 32, the preceding steel 31 is put on the succeeding steel 32 and pressurization with a punch 13 is started. In the state where pressure welding is completed, the preceding steel 31 and the succeeding steel 32 are connected through joint surfaces 30 and also tapered surfaces 32a, 32a are formed on the succeeding thick steel 32. Then, the change in thickness becomes gentle, so the variation of the rolling load in the rolling of the next stage is reduced and break of the steel is effectively prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of a pressing mechanism of a hot steel joining machine.

[0002]

2. Description of the Related Art In conventional hot rolling, slabs are supplied one by one to a rough rolling machine and a finishing rolling machine to perform rolling intermittently. In such intermittent rolling, not only inefficiency itself, but especially in the case of rolling in which the plate thickness of the material to be rolled is thin, there is a risk that the tip end portion of the material to be rolled may be deformed and hit the guide roll. However, there is a risk that the trailing end may be narrowed when it exits the rolling mill and damage the rolling roll. When these inconveniences occur, the rolling line must be stopped to repair the damage. Therefore, conventionally,
Although measures are taken to reduce the rolling speed at the trailing edge, this reduces rolling efficiency.

Further, the front and rear ends of the hot-rolled steel sheet are out of balance with respect to the rolling speed as compared with the central portion, and therefore are out of the proper rolling temperature range, so that the dimension is likely to be out of order. This is because the tip of the hot-rolled steel sheet is passed through the table roller at low speed without tension until it is wound up by the winder, and a sharp tension acts immediately after the start of winding to narrow the width of the sheet. After that, it is wound at a constant speed and a constant tension. Furthermore, after the steel sheet has passed through the rolling mill, it is wound at low speed and without tension.
In this way, at the front and rear ends of the steel sheet after finish rolling, the strip width and the cooling of the steel material change due to the influence of the rolling speed and tension,
If the size is out of order or the temperature is out of the range, the part must be cut off and treated as a downgrade, resulting in a large decrease in production yield.

In order to solve the above problems, in recent years, between a rough rolling mill and a finish rolling mill, a preceding rough rolled steel sheet (hereinafter referred to as "preceding steel material") and a following rough rolled steel sheet ( (Hereinafter referred to as "following steel material") and
A technique of continuously performing finish rolling has been proposed and is being put to practical use. At this time, what is important is the joining technology of the front and rear steel materials, and the scale is removed by the descaling device during rolling, but new scale is generated before reaching the joining place, and this scale Interfere. Therefore, just before the joining, the joining surface is formed while removing the new scale, and pressure welding is performed by the pressing mechanism. An example of this type of technology is shown below.

FIG. 12 is an explanatory view of a conventional hot steel joining method, in which a preceding steel material 101 is lifted by a roll 102 for a certain distance, a trailing steel material 103 is made to face below the rear end of the preceding steel material 101, and a burner 104 is used. In the reducing gas generated, the rear cutter 101a of the preceding steel material 101 is moved by the rotary cutter 105.
The lower surface and the top surface 103a of the trailing steel material 103 are obliquely cut to form a joint surface, and the punch 107a and the die 107 are formed.
In b, the rear end of the preceding steel material 101 and the front end of the following steel material 103 are pressed together.

The pressing mechanism comprises a punch 107a and a die 107b, and the punch 107a has a large flat bottom surface 1.
07c, the die 107b has a large flat top surface 107d. By the way, depending on the production plan, the plate thickness of the trailing steel material 103 may be changed with respect to the plate thickness of the preceding steel material 101.

[0007]

Problems to be Solved by the Invention FIGS. 13 (a) and 13 (b)
FIG. 4 is an explanatory view when joining steel materials having different thicknesses by a conventional press mechanism, in which the preceding steel material 101 is thin and the following steel material 10 is
3 is thick. (A) is a case where the thin leading steel material 101 and the thick trailing steel material 103 are joined with their lower surfaces aligned, and as is clear from the figure, the trailing steel material 103 has a step 103a.
Comes out. (B) is a case where the thin leading steel material 101 and the thick trailing steel material 103 are joined with their upper surfaces aligned, and as is clear from the figure, the end step 103b appears at the tip of the trailing steel material 103.

Since the thickness of the steel material suddenly changes at the steps 103a and 103b, an abnormal rolling reaction force is generated in the rolling mill. Further, due to a rapid change in the amount of reduction, a large amount of tension acts on the steel material and the steel material may break. Then, the objective of this invention is providing the press mechanism which can suppress the fluctuation | variation of rolling load as much as possible when joining the steel materials from which thickness differs.

[0009]

In order to achieve the above object, the first aspect of the present invention is to provide an end portion of a preceding steel material and an end portion of a following steel material having different thicknesses in a reducing or non-oxidizing atmosphere. In the press mechanism in which after descaling in step 1, the sheets are overlapped and sandwiched and joined by a press and a die, a gradient is formed on the inlet side and the outlet side of the press and the die. Since the change of the plate thickness becomes gentle, the change of the rolling load in the rolling in the next step becomes small and the fracture of the steel material can be effectively prevented.

According to a second aspect of the present invention, the end portions of the preceding steel material and the trailing steel material having different thicknesses from each other are descaled in a reducing or non-oxidizing atmosphere, then overlapped and sandwiched and joined by a press and a die. In the press mechanism, a slope is formed on the inlet side and outlet side of the press or the inlet side and outlet side of the punch.

According to a third aspect of the present invention, the end portions of the preceding steel material and the trailing steel material having different thicknesses from each other are descaled in a reducing or non-oxidizing atmosphere, and then superposed and sandwiched and joined by a press and a die. In the pressing mechanism, a slope is formed on the inlet side or the outlet side of the press and a slope is formed on the outlet side or the inlet side of the die. Since the change of the plate thickness becomes gentle, the change of the rolling load in the rolling in the next step becomes small and the fracture of the steel material can be effectively prevented.

[0012]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a layout diagram of a hot rolling line according to the present invention. The hot rolling line includes a rough rolling mill 1, a coil box 2 that winds a rolled material and rewinds it while keeping it warm, a leveler 3, and a rolled material. A crop shear 4, which cuts in the direction, a running joining machine 10 according to the present invention, a finish rolling machine 6, a high speed shear 7, and a winding machine 8 are arranged in this order.

The steel material rolled from the slab 9 by the rough rolling mill 1 is wound on the coil box 2 and then unwound, and the leveler 3 corrects the winding tendency of the front and rear ends. The front and rear ends of the steel material are cut by the crop shear 4 in order to secure the surfaces to be joined.
Then, the running steel joining machine 10 joins the trailing end of the preceding steel material and the leading end of the following steel material, finish rolling is performed by the finishing rolling machine 6, and then the winding is performed by the winding machine 8 so that the winding amount becomes constant. When it reaches, it is cut with a high speed shear 7 to form a hot rolled coil.

The structure and operation of the running joint machine will be described with reference to FIGS. 2 to 5. Regarding the shapes of the punch and die in these figures, the shapes shown in FIG. 6 and subsequent figures have priority. FIG. 2 is a side view of the running joint machine according to the present invention, showing an example of the running joint machine. The running joining machine 10 includes a traveling carriage 11, a press cylinder 12 for pressing, a punch 13 and a die 14, and a first clamper 1 arranged on the exit side (right side in the drawing) of the die 14.
5, pinch roll 16, rolls 17, 17 and burner 2
1, an elevating frame 18 and elevating cylinders 19 and 19 for moving them up and down collectively, a second clamper 22, a pinch roll 23 and rolls 24 and 24 arranged on the entrance side of the die 14, and a burner 25. , Rotary cutter 26
Consists of Reference numeral 27 is a first clamper working cylinder, and 28 is a second clamper working cylinder.

The operation of the running joint machine 10 having the above construction will be described below. 3 (a), (b) to FIG. 5 (a),
(B) is an operation explanatory view of the running joint machine. In FIG. 3A, when the preceding steel material 31 reaches a predetermined position, the first clamper operating cylinder 27 is operated to lower the first clamper 15, and the first clamper 15 fixes the preceding steel material 31. In FIG. 3B, the lifting cylinder 1 is indicated by the arrow.
9 and 19 are operated to lift the first clamper 15 and the like to a predetermined height. Next, as shown by the arrow, the tip of the trailing steel material 32 is advanced to a predetermined position and fixed by the second clamper 22. FIG.
In (a), the burners 21 and 25 are operated to wrap the trailing end of the preceding steel material 31 and the leading end of the following steel material 32 with reducing flame. In FIG. 4 (b), the rotary cutter 26 rotated clockwise in the drawing is moved so as to draw a parallelogram as shown by the arrow, and the tip of the trailing steel 32 and the trailing end of the preceding steel 31 are cut diagonally. To do. This step will be described in detail later.

In FIG. 5 (a), the preceding steel material 31 is lowered as shown by the arrow, and the rear end thereof is superposed on the leading end of the following steel material 32. Then lower the punch 13 as shown by the arrow,
The trailing steel members 31 and 32 are pressed against each other. The arrow and the arrow may be simultaneously executed to press the leading and trailing steel materials 31 and 32 against each other. In FIG. 5B, the punch 13 and the first and second clampers 15 and 22 are opened to advance the connected leading and trailing steel materials 31 and 32. 33 is a joint. The above steps are carried out while the traveling carriage 11 is traveling appropriately. Since it is not necessary to stop the preceding steel material 31 and the following steel material 32, the rolling operation can be continued.

FIG. 6 is a side sectional view of the press mechanism according to the present invention (first embodiment). When the flow direction of the steel material is indicated by arrow a, this press mechanism has a slope 13a on the entrance side of the punch 13. , The slope 13b is provided on the outlet side, the slope 14a is provided on the inlet side of the die 14, and the slope 14b is provided on the outlet side.

The operation of the press mechanism having the above structure will be described below. FIGS. 7A to 7D are explanatory views of the operation of the first embodiment. In (a), the thin leading steel material 31 is replaced with the thick trailing steel material 32.
To face. In (b), the trailing steel 32 and the preceding steel 31
And press the punch 13 to start pressing. (C) shows the completion state of pressure welding, showing that the preceding steel material 31 and the following steel material 32 are connected via the joint surface 30, and that the thick following steel material 32 can be formed with the tapered surfaces 32a, 32a. Indicates. Since the rate of change of the plate thickness is relaxed by the action of the tapered surfaces 32a, 32a, the influence on the rolling mill is reduced.

(D) is an example in which the thick leading steel material 31 and the thin trailing steel material 32 are joined. Since the tapered surfaces 31a and 31a can be formed on the thick leading steel material 31, the rate of change of the plate thickness is similarly relaxed. Therefore, the influence on the rolling mill is reduced.

FIG. 8 is a side sectional view (second embodiment) of the press mechanism according to the present invention.
3 has a slope 13a on the inlet side and a slope 13b on the outlet side, and the die 14 remains flat.

9 (a) and 9 (b) are explanatory views of the operation of the second embodiment. (A) shows the completion state of pressure welding, showing that the thin leading steel material 31 and the thick trailing steel material 32 are connected via the joint surface 30, and that the thick trailing steel material 32 can be formed with the tapered surface 32a. Indicates. Since the rate of change in strip thickness is moderated by the action of the tapered surface 32a, the influence on the rolling mill is reduced. (B) is an example in which a thick leading steel material 31 and a thin trailing steel material 32 are joined. Since the tapered surface 31a can be formed on the thick leading steel material 31, the change rate of the plate thickness is similarly mitigated. It has less effect. In the second embodiment, the punch 13 is left flat and the die 1
Similar effects can be obtained even if 4 is provided with a gradient.

FIG. 10 is a side sectional view (third embodiment) of the pressing mechanism according to the present invention. When the flow direction of the steel material is indicated by the arrow b, this pressing mechanism has a slope 13a on the entrance side of the punch 13. And a slope 14b is provided on the exit side of the die 14. Note that the exit side of the punch 13 may be provided with a slope, and the entrance side of the die 14 may be provided with a slope.

11 (a) and 11 (b) are explanatory views of the operation of the third embodiment. (A) shows the completion state of pressure welding, showing that the thin leading steel material 31 and the thick trailing steel material 32 are connected via the joint surface 30, and that the thick trailing steel material 32 can be formed with the tapered surface 32a. Indicates. Since the rate of change in strip thickness is moderated by the action of the tapered surface 32a, the influence on the rolling mill is reduced. (B) is an example in which a thick leading steel material 31 and a thin trailing steel material 32 are joined. Since the tapered surface 31a can be formed on the thick leading steel material 31, the change rate of the plate thickness is similarly mitigated. It has less effect.

[0024]

Embodiments of the present invention will be described below. However, the present invention is not limited to the embodiment. Examples 1 to 3 and Comparative Example 1; (1) Test Material; Carbon Steel Sheet (C: 0.1%, Si: 0.5%, Mn: 1.
2%) One steel plate thickness 25 mm, plate width 300 mm, length 1,
000mm Plate thickness of the other steel 30mm, plate width 300mm, length 1,
000mm temperature 1,250 ℃

(2) Direct flame reducing flame condition; burner type; nozzle mixing system fuel; LPG 6Nm ³ / hr / 1 burner oxygen enrichment ratio; 60% air ratio m; 0.6 burner arrangement; steel width direction Multiple arrays in. The burner blows the air-fuel mixture from a ring-shaped slit nozzle to generate a reducing flame.

(3) Cutting conditions; type of cutter; cylindrical rotary cutter (maximum outer diameter 300 m
m) Chip arrangement; zigzag arrangement Rotation speed; 1,500 rpm Feed rate; 6,000 mm / min Cutting surface width; 30 mm In addition, cutting was started 1 second after burner ignition.

(4) Pressure welding condition; pressure welding temperature; 1,050 ° C. superposition amount (width); 25 mm press mechanism used; 300 ton press atmosphere; reducing flame injection After the cutting is completed and the cutting device is evacuated, Pressing was started after 1 second.

(5) Finish rolling conditions: Number of rolling mills: 3 stages (40%, 35%, 30% reduction ratio) Tension: 1st to 2nd stage Approx. 2.0 kgf / mm ² Tension: 2nd Stage-third stage About 4.0 kgf / mm ² Steel material temperature; 1,000 ° C Finished thickness; 8.2 mm

[0029]

[Table 1]

Example 1; 25 mm preceding steel material and 30 mm
The following steel materials were joined by the press mechanism of FIG. 6 in which both the punch and the die were provided with both gradients. In FIG. 6, the gradient angle θ was 7.5 °, the entrance-side gradient length L1 was 20 mm, the exit-side gradient length L2 was 20 mm, and the remaining length L3 was 60 mm. After joining, the steel material was applied to a finish rolling mill, and the rolling load smoothly increased from 160 tons to 190 tons. The rolling speed was controlled accordingly, and rolling could be performed with the set tension. Yes.

Comparative Example 1; 25 mm preceding steel material and 30 mm
The following steel materials were joined by the press mechanism shown in FIG. 13 in which neither the punch nor the die was provided with both gradients. After joining, when a steel material with a step of 5 mm was placed on the finishing mill, the rolling load was 1
Suddenly increased from 60 tons to 210 tons with a tension of 8 kg
It fractured beyond f / mm ² . Therefore, the evaluation is x.

Example 2; 25 mm of preceding steel material and 30 mm
The following steel materials were joined by the press mechanism shown in FIG. 8 in which the punch was provided with both gradients. In addition, in FIG. 8, the inclination angle θ is 15 °,
Inlet slope length L1 is 20 mm, Outlet slope length L
2 was 20 mm and the remaining length L3 was 60 mm. After joining, the steel material was applied to a finishing mill and the rolling load was 16
Since the temperature was smoothly increased from 0 tons to 190 tons, the rolling speed was controlled accordingly, and rolling could be performed with the set tension, the evaluation is ◯.

Example 3; 25 mm of preceding steel material and 30 mm
The following steel materials were joined by the press mechanism of FIG. 10 having a slope on the entrance side of the punch and a slope on the exit side of the die. In addition,
In FIG. 10, the gradient angle θ is 15 °, the length L1 of the gradient on the entrance side (or the exit side) is 20 mm, and the remaining length L3 is 80 mm.
And After joining, when the steel material was applied to the finishing mill, the rolling load increased smoothly from 160 tons to 190 tons,
The rolling speed was controlled accordingly, and rolling could be carried out with the set tension, so the evaluation is ◯.

Although not described as an example, similar results were obtained for joining of a 30 mm leading steel material and a 25 mm trailing steel material by exchanging the front and rear plate thicknesses.

[0035]

The present invention has the following effects due to the above configuration. According to a first aspect of the present invention, there is provided a press mechanism in which an end portion of a preceding steel material and an end portion of a following steel material having different thicknesses are descaled in a reducing or non-oxidizing atmosphere, and then overlapped and sandwiched and joined by a press and a die. A gradient is formed on the inlet side and the outlet side of the press and die. Since the change of the plate thickness becomes gentle, the change of the rolling load in the rolling in the next step becomes small and the fracture of the steel material can be effectively prevented.

According to a second aspect of the present invention, the end portion of the preceding steel material and the end portion of the following steel material having different thicknesses are descaled in a reducing or non-oxidizing atmosphere, then overlapped and sandwiched and joined by a press and a die. In the press mechanism, a slope is formed on the inlet side and outlet side of the press or the inlet side and outlet side of the punch. In addition to the effect of the first aspect, the die allowance of the press mechanism can be reduced.

According to a third aspect of the present invention, the end portions of the preceding steel material and the trailing steel material having different thicknesses from each other are descaled in a reducing or non-oxidizing atmosphere, then overlapped and sandwiched and joined by a press and a die. In the pressing mechanism, a slope is formed on the inlet side or the outlet side of the press and a slope is formed on the outlet side or the inlet side of the die. Since the change of the plate thickness becomes gentle, the change of the rolling load in the rolling in the next step becomes small and the fracture of the steel material can be effectively prevented.

[Brief description of drawings]

FIG. 1 is a layout diagram of a hot rolling line according to the present invention.

FIG. 2 is a side view of the running joint machine according to the present invention.

[Fig. 3] Operation explanatory diagram of the running joint machine

FIG. 4 is an explanatory view of the action of the running joint machine.

FIG. 5 is an explanatory view of the action of the running joint machine.

FIG. 6 is a side sectional view of a pressing mechanism according to the present invention (first embodiment).

FIG. 7 is an operation explanatory view of the first embodiment.

FIG. 8 is a side sectional view of a press mechanism according to the present invention (second embodiment).

FIG. 9 is an explanatory view of the operation of the second embodiment.

FIG. 10 is a side sectional view of a pressing mechanism according to the present invention (third part)
Example)

FIG. 11 is an explanatory view of the operation of the third embodiment.

FIG. 12 is an explanatory view of a conventional hot steel joining method.

FIG. 13 is an explanatory view when joining steel materials having different thicknesses by a conventional pressing mechanism.

[Explanation of symbols]

1 ... Rough rolling mill, 6 ... Finishing rolling mill, 10 ... Running joining machine, 1
3 ... Punch, 13a ... Inlet side slope, 13b ... Outlet side slope, 14 ... Die, 14a ... Inlet side slope, 14b ... Outlet side slope, 30 ... Joining surface, 31 ... Leading steel material, 32 ... Trailing Steel material, θ ... Gradient angle.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location B23K 20/02 B23K 20/02 (72) Inventor Toshihiro Mori 4-5 Kitahama, Chuo-ku, Osaka City, Osaka Prefecture No. 33 Sumitomo Metal Industries, Ltd. (72) Inventor Masami Oki 4-53, Kitahama, Chuo-ku, Osaka-shi, Osaka Prefecture Sumitomo Metal Industries, Ltd. (72) Nobuhiro Tazo Shinaka, Isogo-ku, Yokohama-shi, Kanagawa Haramachi No. 1 Ishikawajima-Harima Heavy Industries Co., Ltd. Yokohama Engineering Center (72) Inventor Norio Iwanami Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa Ishikawajima Harima Heavy Industries Co., Ltd. Yokohama Engineering Center

Claims (3)

[Claims] 1. A press mechanism in which an end portion of a preceding steel material and an end portion of a following steel material having different thicknesses are descaled in a reducing or non-oxidizing atmosphere, and then overlapped and sandwiched and joined by a press and a die. , On the inlet and outlet sides of the press and die,
A press mechanism for a hot steel joining machine characterized by forming a gradient. 2. A press mechanism in which an end portion of a preceding steel material and an end portion of a following steel material having different thicknesses are descaled in a reducing or non-oxidizing atmosphere, and then overlapped and press-joined with a press and a die. A press mechanism of a hot steel joining machine, wherein a gradient is formed on the inlet side and outlet side of the press or the inlet side and outlet side of the punch. 3. A press mechanism in which an end portion of a preceding steel material and an end portion of a following steel material having different thicknesses are descaled in a reducing or non-oxidizing atmosphere, and then overlapped and sandwiched and joined by a press and a die. A press mechanism for a hot steel joining machine, wherein a gradient is formed on an inlet side or an outlet side of the press and a gradient is formed on an outlet side or an inlet side of the die.