JPS59189003A - Manufacture of rough t-shaped billet - Google Patents

Abstract

PURPOSE:To manufacture a T-shaped steel highly accurately and efficiently by edging a slab by using a roll at one side having a grooved bottom formed to be approximately equal to the slab thickness and a roll at the other side having a grooved bottom formed to be specific times the slab thickness. CONSTITUTION:Both of the dimensions of grooves 12a, 14a of a roll at one side are aproximately equal to the thickness (t) of a slab 15. Further, both of the dimensions of grooves 12b, 14b of a roll at the other side are regulated within the limits 1.2-3.0 (t).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing T-shaped steel slabs, and aims to provide a preferred manufacturing method for rough-shaped steel slabs for manufacturing Tm steel with high precision and efficiency. It is something to do.

T-shaped steel has been known for a long time)! l] Chiko's T-shaped steel is shown in Fig. 1, and is made by integrally forming a stem part 10 and a flange part 11, and is widely used in fields such as shipbuilding and shipbuilding. The fact that each part is required to have various dimensions (thickness and width of the flange part, thickness and height of the stem part) depending on the purpose, usage conditions, location, etc. is a major reason. However, as one method for efficiently manufacturing T-beam steels of various dimensions and shapes, a manufacturing method using a universal mill was proposed in Japanese Patent Publication No. 19671/1971.
In this proposal, T-shaped steel slabs were rolled using a universal mill and a finishing Unihersal Mill V to produce T-shaped steel, and 21 products with various dimensions were manufactured. It is considered to be an effective method for sharing rolling rolls. However, even with such technology, the rolling material value of the rolling material is limited to the rough universal mill. There is no preferred method for obtaining gold, and it is stated that the steel billet is simply made into a roughly T-shape by a breakdown mill equipped with a known blooming IE rolling machine and a caliber roll with a hole shape. al
It is l. Since this method (with a lid) uses a conventionally known caliber roll, there is no flexibility in the dimensions of the rough shaped steel pieces obtained, so it is difficult to obtain products with various dimensions. In this case, it is necessary to prepare various breakdown rolls having various hole shapes depending on the dimensions of the final product, which has the disadvantage that the production cost is inevitably high even if the roll collapses.

The present invention was devised after repeated studies in view of the above-mentioned circumstances, and includes products having various dimensions. When manufacturing, the breakdown mill can be shared in a wide area, and T-shaped steel slabs can be efficiently prepared using continuous casting slabs, which have been widely adopted in recent years for the purpose of improving yield. It was very successful. That is, to explain the present invention, FIG. 2 shows an example of the groove shape of a breakdown roll for realizing the manufacturing method according to the present invention, and FIG. It is a slab 15 manufactured by a machine, and has widths W and il and width t. However, in the present invention, the slab 15 is pressed in the box hole mold 12 with the width W direction as the upper and lower sides as shown in FIG. The hole type) has a relatively narrow hole bottom dimension that is equivalent to the thickness of the slab 15, whereas the lower roll hole type 12b (or upper roll hole type) has a wider thickness of the slab 15. 1.2 to 3.0 times the size of the slab.
By performing the width reduction, a roughly T-shaped roughly shaped steel piece 6 is obtained as shown in FIG.

To further explain these relationships, the hole pattern 12 in one roll, shown as LI+"2 in FIG.
The dimensions of L3. The dimensions of the holes 12b, 14b in the other roll, designated as L4, are 1.2t to 3. O
Must be within the range of t. In this way, the hole 128,
The reason why the dimension of 14 m is set to be approximately the same as the thickness of the material slab 15 is because if it is too small than the thickness of the material slab, not only will unnecessary dog bones be produced, but also the material will not be restrained by the hole side wall. During rolling, problems such as twisting and falling occur. In the present invention, unlike conventional width reduction rolling, in order to form a dogbone on one side, restraint by the groove sidewall is extremely important as described above. In addition, the dimensions L3 and L4 of the hole molds 12b and 14b need to be in the range of 1.2 to 3.0 times the thickness of the material slab.If it is less than 1.2 times, the dogbone will be too small, so The amount of wall thickness becomes too small for the steel part, and it becomes difficult to maintain an appropriate rolling reduction balance between the flange part and the stem part in the subsequent rolling process, and large bends are likely to occur during rolling. On the other hand, if it is 3.0 times or more, it will not be possible to secure an appropriate thickness of 7 lunges. This was determined from the experimental results of the present inventors, which showed that no matter how the rolling schedule was changed, the flange width obtained by dog bones was three times or less the normal flange thickness.

According to the box hole type of the present invention as described above, the piece 114
It is possible to obtain a substantially T-shaped steel slab having a dog bone only at 11, and by simply selecting the width of the slab 15 shown in FIG. 3 appropriately and changing the spacing between the upper and lower rolls 1 and 2 in the final pass, Since the height of the rough-shaped steel billet (as shown in Figure 1) can be changed arbitrarily, the same breakdown roll can be used for a wide range of product dimensions, and manufacturing costs can be kept low. .

Another feature of the present invention is that the roll diameter at the bottom of the box-hole type mentioned above is actively differentiated between the upper and lower rolls to suppress bending during rolling. The roll diameter at the groove bottom of the upper roll (or the upper roll) is 1.1 to 163 times the roll diameter at the groove bottom of the upper roll (or the lower roll). That is, in the present invention, as shown in FIG. 4, the groove sidewall of the upper roll 1 is in contact with the material 15 from the initial stage of rolling, while the lower roll's groove sidewall and the material 15 are in contact with each other at the initial stage of rolling. There is no contact, and as the rolling progresses (that is, as the distance between the lower rolls becomes narrower), dog bones are formed and the hole sidewalls and the material 15 come into contact. In other words, at the initial stage, the upper part of the material tries to stretch in the drawing direction due to the restraint from the sides, but in the lower part of the material 15, the meat flows in the width direction to the left of the dog bone formation, and the elongation in the drawing direction is insignificant, so it is difficult to roll. There is a tendency to curve downwards in the middle.

Furthermore, as rolling progresses and the grooved sidewall of the lower roll begins to come into contact with the material 15, the lower part of the material 15 also begins to elongate in the stretching direction gradually, and when the dogbone is completely formed, the same stretching as in the upper part begins. At this stage, it is desirable that the difference in diameter between the upper and lower rolls is as small as possible.

In this way, in the present invention, the mechanism of rolling detouring is different between the early stage and the latter stage, so it is not possible to avoid rolling detouring by simply making the roll diameters of the upper and lower rolls the same as in the past. According to detailed repeated experiments, it was found that the roll (-'f
: It has been confirmed that when the rolling thickness is set to 1.1 to 1.3 times that of the gold-finished roll, the bending can be suppressed to an acceptable level from the initial stage to the latter half of rolling.

Another feature of the present invention is that in the intermediate or finishing stage of the above-mentioned narrow width reduction rolling, the material 15 is rolled at 90° or 270° as shown in FIG.
Rolling is performed using a shaping hole die 13 which is rotated and has a flange on only one side. That is, the forming hole mold 13 shown in FIG. 2 is an example of a hole mold in such a case, and such a forming hole mold 13 is used in the intermediate stage or finishing stage of width reduction rolling as described above. By rolling, the protrusion shown in Fig. 4 can be formed, and by using this forming hole die 13 in the finishing stage of width reduction and pressing, the stem portion of the rough shaped steel piece 6 shown in Fig. 6 can be formed. The thickness T can be changed as appropriate.

Specific embodiments of the present invention will be described below.

A material slab obtained by continuous casting with a thickness of 220mm and a width W of 1250i was used, and as the box hole mold 12, as shown in Fig. 8, the bottom width of the hole was 220mm and the depth was 220mm. The upper roll of pus and the lower roll with a hole bottom width of 420 fins and a depth of 180 fins were used, and the forming hole mold 1
3, the width of the flange part molded part is 180 ran, and the width of the stem part molded part is 600 ran, as shown in Figure 9.
m is used, and the number of passes is box hole type 1.
2, 13 passes were performed in the forming hole die 13, and 3 passes were performed in the intermediate stage of width reduction rolling, and 11 passes were performed in the finishing stage. The dimensions of the obtained T-shaped steel slab are as shown in the following table, and it was confirmed that it was an extremely good T-shaped steel slab.

According to the present invention as explained above, one roll has a grooved bottom that is approximately the same as the bottom of the slab to be rolled, and the other roll has a grooved bottom that is 1.2 to 3 times the thickness of the slab. By performing width reduction rolling of the above-mentioned slab using the groove between the two rolls, one of the roll grooves can be used to properly bite in the entire 1g direction of the slab, and the side surface of the slab can be effectively restrained and held by the groove side wall. It allows width reduction rolling to be carried out, does not generate unnecessary dogbones in the area, and can effectively prevent the slab from twisting or falling during rolling, and the other roll has preferable dogbones only on one side of the slab. At the same time, the amount of thickness of the 7 flange part is appropriately obtained relative to the stem part, and the rolling reduction ratio of the flange part and stem part in the subsequent rolling process is precisely balanced. This invention is capable of producing approximately T-shaped rough-shaped steel pieces with high precision and efficiency while avoiding the above problems, and is an invention that has great industrial effects.

According to the above-described embodiment of the present invention, the roll diameter at the bottom of one of the grooves is set to 1.1 to 1.3 times the diameter of the roll at the bottom of the other groove, so that the rolling speed is reduced. In the initial stage, the rolling oil is adjusted appropriately and immediately to the difference in the amount of slab stretching in one roll hole and the other hole, and to the fluctuation of the difference in the amount of drawing due to dog bone formation in the other hole area of f&. can be suppressed. Furthermore, in either or both of the intermediate stage of rolling in the width direction of the slab and the finishing stage in each of the grooves of the upper and lower rolls as described above, the material is turned over, and a forming groove having a flange part hole only in one side 111 is used. By rolling, the thickness of the stem can be arbitrarily changed and adjusted, and a preferable T-shaped steel piece can be obtained by any of these methods.

[Brief explanation of the drawing]

The drawings show the technical contents of the present invention, and FIG. 1 is an explanatory diagram of a T-shaped steel, FIG. 2 is an explanatory diagram of a hole shape of a breakdown roll for carrying out the method of the present invention, and FIG. An explanatory diagram of the slab which is the rolled material, Fig. 4 is an explanation of the rolling condition by the box hole type, and Fig. 1 + L 5 is an explanatory diagram of the twisted state of the material when the hole type is inappropriate, and Fig. 6 is a rough shaped steel piece. Fig. 7 is an explanatory drawing of the rolling state by the forming hole die, Fig. 8 is an explanatory drawing of
The figure is an explanatory diagram of the box hole mold used as an example, and Fig. 9 is an explanatory diagram of the box hole mold used as an example.
It is an explanatory diagram. However, in these drawings, 1 is one roll, 2
ri rolls on both sides, 12 and 14 are box hole types, i2a, 14a are hole types on one roll, 12
b, 141)! ,"1. Hole shape in the other roll,
Reference numeral 13 indicates a forming hole pattern, 13a indicates a hole pattern on one roll, 13b indicates a hole pattern on the other roll, and 15 indicates a slab.

Claims (1)

[Scope of Claims] 1. One roll having a groove bottom that is approximately the same thickness as the slab to be rolled and the other roll having a groove bottom that is 1.2 to 3 times the thickness of the slab to be rolled. A method for manufacturing a T-shaped assembled steel piece, characterized in that width reduction rolling of the slab is carried out using a hole shape between the two. 2. For the roll diameter at the bottom of the hole that is approximately the same as the thickness of the slab to be rolled by IE, the roll diameter at the bottom of the hole is 1.2 to 3 times the thickness of the slab, and is 1.1 to 1.3. A method for manufacturing a T-shaped assembled steel billet according to claim g1, in which rolling is performed through holes between rolled rolls. 3. In either or both of the intermediate stage and the finishing stage, the material is rotated by 90 degrees or an integral multiple thereof and rolled with a forming hole having a flange hole on only one side; or, A method for hardening a T-shaped assembled steel piece as described in any of Item 2.