JP3714780B2 - Reduction flame pressure welding method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reducing flame pressure welding method and apparatus for joining a preceding rolled material and a subsequent rolled material in a hot rolling facility.
[0002]
[Prior art]
In a conventional hot rolling facility (hot strip mill), bar materials rolled by a roughing mill are separately supplied to a finishing mill to obtain a strip material having a desired plate thickness. However, with such means, the entire rolled material cannot be uniformly rolled, and the end portions (front end portion and rear end portion) of the rolled material are likely to be defective. Therefore, there is a problem that it is difficult to increase the rolling speed.
[0003]
In order to solve such a problem, the inventors of the present invention, as illustrated in FIG. 3, horizontally arranges a carriage 12 that travels in the rolling direction and a rear end portion of the rolling material 1 that is attached to and precedes the carriage. A rear end clamping device 14 that can be moved up and down by being sandwiched between the front end, a front end clamping device 16 that horizontally attaches the front end of the rolled material 2 that is mounted on the carriage, and a lower surface of the rear end of the preceding rolled material A processing device 18 that cuts the top surface of the tip of the subsequent rolled material, a reduction holding device 20 that holds the processed surface in a reduced state, and a rolled material that overlaps the processed surfaces of the preceding rolled material and the subsequent rolled material, A rolled material joining apparatus 10 including a pressure welding apparatus 22 that compresses and joins to approximately the same thickness has been invented and has already been filed (for example, JP-A-7-323306, JP-A-8-252609, etc.).
[0004]
With this joining device, the trailing end of the preceding rolled material and the leading end of the succeeding rolled material can be joined while traveling together with the rolled material, and the entire width of the rolled material can be joined with sufficient joining strength in a short time. The joints can be processed almost uniformly with little unevenness in the joints, whereby the rolled material can be continuously supplied to the finishing mill. Hereinafter, a joining device that joins the rolled material while traveling is referred to as a “running joining device”.
[0005]
[Problems to be solved by the invention]
In the running joint apparatus described above, the processed surfaces are held in a reduced state, the processed surfaces of the preceding rolled material and the subsequent rolled material are overlapped, and compressed and joined to the same thickness as the original rolled material by the pressure welding device 22. It was. In this case, a rectangular mold that is uniform in the width direction is used.
[0006]
However, the width end portion of the rolled material joined in this way has a relatively low joining strength. Therefore, when a strong tension is applied in the downstream finishing rolling process, looper, etc., a gap is formed in the joint portion at the width end portion. (Mouth open).
[0007]
The present invention has been developed to solve such problems. An object of the present invention is to provide a reducing flame welding method and apparatus hardly a gap at the junction of the bonding strength enhanced, strong under tension rolled material width direction end portion of the strip widthwise end portions It is in.
[0008]
[Means for Solving the Problems]
According to the present invention, in the reduction flame pressure welding method in which the processed surface is held in a reduced state and the processed surfaces of the preceding rolled material and the subsequent rolled material are overlapped and pressed, the longitudinal distance of the rolled material on the pressed surface is the rolled material. using the press mold that is narrower composed widely rolled material width direction end portion in the widthwise center, and pressed so that the junction is equal to or thinner than the original thickness of the preceding rolled material and following rolled material, A reducing flame pressure welding method is provided.
[0009]
According to a preferred embodiment of the present invention, the thickness of the joint portion is set so that the joint portion is not rolled during rolling in the next step.
[0010]
Further, according to the present invention, in the reduction flame pressure welding apparatus in which the processed surface is held in a reduced state and the processed surfaces of the preceding rolled material and the subsequent rolled material are overlapped and pressed, the longitudinal direction distance of the pressed surface of the rolled material is: It has a pressure die which is narrower composed widely rolled material width direction end portion in the rolled material width direction center, the piezoelectric Sekkin type, are equal to the joint than the original thickness of the preceding rolled material and following rolled Alternatively, there is provided a reducing flame pressure welding apparatus characterized by being pressed so as to be thin.
[0011]
According to the method and apparatus of the present invention, the thickness of the joint is thinner than the original thickness of the preceding rolled material and the subsequent rolled material, and the longitudinal distance of the rolled material in the joint is at the center in the width direction of the rolled material. Widely narrow at the end in the width direction of the rolled material . When the rolled material formed in this way is rolled again in the downstream finish rolling step, the elongation in the rolling direction of the rolled material is small at the center in the width direction of the rolled material where the longitudinal distance of the thin-walled portion is large, Conversely, the elongation in the rolling direction of the rolled material increases at the end of the rolled material in the width direction where the longitudinal direction distance of the thin-walled portion is small. Therefore, in normal rolling, the elongation at the end in the width direction of the rolled material is small, and a strong tensile force acts on this portion. On the contrary, in the present invention, the elongation at the end in the width direction of the rolled material is large. Is relaxed and becomes relatively small. As a result, the bonding strength at the end in the width direction of the rolled material is substantially increased, and the tensile force at the end in the width direction of the rolled material can be relaxed even when a strong tension is applied as a whole, and a gap is hardly generated.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected to the common part in each figure, and the overlapping description is abbreviate | omitted. FIG. 1 is a partial configuration diagram of a reducing flame pressure welding apparatus according to the present invention. In this figure, (A) shows the upper die 30a and the lower die 30b of the pressure welding device 22, and the pressure-welded surfaces of the preceding rolled material 1 and the succeeding rolled material 2 are overlapped. In FIG. 1A, the hatched portion indicates a portion that is recessed due to plastic deformation by pressure welding.
[0013]
FIG. 1 (B) is an AA arrow view of FIG. 1 (A), and the subsequent rolled material 2 is omitted. In this figure, 31a is a plane part and 31b is an inclined part. As shown in this figure, the rolled material longitudinal dimension of the mold 30 (lower mold 30b in the figure) is composed narrowly widely rolled material width direction end portion in the rolled material width direction center. For example, if the width of the mold at the center in the width direction of the rolled material is a and the width of the mold at the end in the width direction of the rolled material is b, a> b, and preferably a / b = 1.3 or more. Is good. 1B shows the lower mold 30b, the same applies to the upper mold 30a.
[0014]
FIG. 2 is a plan view (A) and a partial cross-sectional view (B) taken along line BB of the joint portion 32 that is press-contacted using the mold 30 of FIG. When the metal mold 30 shown in FIG. 1 is used for pressure welding, the shape of the joint portion 32 is such that the width of the central portion in the width direction of the rolled material is a and the width of the end portion in the width direction of the rolled material is b. a> b, and preferably a / b = 1.3 or more. In FIG. 2 (A), the hatched portion indicates the overlapped portion of the preceding rolled material 1 and the subsequent rolled material 2, and in this example, they are overlapped with a constant width in the longitudinal direction of the rolled material . In addition, this invention is not limited to this, For example, you may change the overlap width in the rolling material width direction center and a rolling material width direction edge part.
[0015]
According to the method of the present invention, as shown in FIG. 2 (B), the joining portion 32 is made thinner than the original thicknesses t _{1 and} t ₂ of the preceding rolled material 1 and the subsequent rolled material 2. Press contact. Preferably, the thickness of the joint portion 32 is set so that the joint portion 32 is not rolled by rolling in the next step. That is, the joining part 32 becomes thinner by Δh / 2 on one side than the original thicknesses t _{1 and} t ₂ of the preceding rolled material 1 and the succeeding rolled material 2, and this value (Δh / 2) is about 5 to 5. It should be about 10 mm.
[0016]
Further, a gradient (inclined portion 32 b) is formed in the joint portion 32 by the inclined portion 31 b of the mold 30. By providing the inclined portion 32b, the change in the plate thickness becomes gradual, the fluctuation of the rolling load in rolling in the next process is reduced, and the steel material can be effectively prevented from breaking.
[0017]
According to the above-described method and apparatus of the present invention, the thickness of the joint portion 32 becomes thinner than any of the original thicknesses t _{1 and} t ₂ of the preceding rolled material 1 and the subsequent rolled material 2, and the joined portion 32. The length in the longitudinal direction of the rolled material is wide at the center in the width direction of the rolled material and becomes narrow at the ends in the width direction of the rolled material . When the rolled materials 1 and 2 formed in this way are rolled again in the downstream finish rolling step, the rolling material in the width direction central portion of the rolled material having a large longitudinal distance in the thin material portion (joint portion 32) On the other hand, the elongation in the rolling direction of the rolled material increases at the end in the width direction of the rolled material where the elongation in the rolling direction is small and the distance in the longitudinal direction of the thin-walled portion is small. Therefore, in normal rolling, the elongation at the end in the width direction of the rolled material is small, and a strong tensile force acts on this portion. On the contrary, in the present invention, the elongation at the end in the width direction of the rolled material is large. Is relaxed and becomes relatively small. As a result, the bonding strength at the end in the width direction of the rolled material is substantially increased, and the tensile force at the end in the width direction of the rolled material can be relaxed even when a strong tension is applied as a whole, and a gap is hardly generated.
[0018]
In addition, this invention is not limited to embodiment mentioned above, Of course, it can change variously in the range which does not deviate from the summary of this invention.
[0019]
【The invention's effect】
As described above, the reducing flame welding method and apparatus of the present invention to enhance the bonding strength of the rolled material width direction end portions, hardly a gap at the junction of the strip end portion in the width direction even under the high tension, etc. It has an excellent effect.
[Brief description of the drawings]
FIG. 1 is a partial configuration diagram of a reducing flame pressure welding apparatus according to the present invention.
FIGS. 2A and 2B are a plan view and a partial cross-sectional view of a joint portion.
FIG. 3 is a configuration diagram of a conventional running joint apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Pre-rolled material 2 Subsequent rolled material 4 Roller 10 Rolled material joining apparatus 12 Carriage 14 Trailing end clamping apparatus 16 End clamping apparatus 18 Processing apparatus 20 Reduction holding apparatus 22 Pressure welding apparatus 30 Mold 30a Upper mold 30b Lower mold 32 Joint part H Processing height L Pressure height B Rolling height

Claims (3)

In the reducing flame pressure welding method in which the processed surface is held in a reduced state and the processed surfaces of the preceding rolled material and the subsequent rolled material are overlapped and pressed,
Using a press- contacting die in which the longitudinal direction distance of the pressed surface is wide at the center in the width direction of the rolled material and narrow at the end in the width direction of the rolled material, it is joined rather than the original thickness of the preceding rolled material and the subsequent rolled material. A reducing flame pressure welding method, characterized in that pressure welding is performed so that the portions are equal or thin. 2. The reducing flame pressure welding method according to claim 1, wherein the thickness of the joint portion is set so that the joint portion is not rolled during rolling in the next step. In the reducing flame pressure welding apparatus that holds the processed surface in a reduced state and presses the processed surface of the preceding rolled material and the subsequent rolled material on top of each other,
The longitudinal direction distance of the rolling material of the pressure contact surface has a pressure die that is wide at the center in the width direction of the rolled material and narrow at the end in the width direction of the rolled material. A reducing flame pressure welding apparatus, wherein pressure welding is performed so that the joint portion is equal to or thinner than the original thickness of.

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