JPH0466202A - Manufacture of channel bar - Google Patents

Abstract

PURPOSE:To obtain a channel bar excellent in butt weldability and appearance by orderly applying rough rolling process by which an intermediate product is formed, finishing process by which a channel bar is formed to a base stock. CONSTITUTION:Caliber rolling is applied to the base stock 1 which is heated at a prescribed temp. with plural pairs of 2-high rolling roll which are arranged in parallel each other, of which at least one of them is revolved with a driving device and on which prescribed calibers are formed. A pair of flange parts 3 are outwardly inclined to each perpendicular, the web part 4 is made into a projecting shape that the web part is protruded on the side of the flange part 3 and that its middle part 4a is flat, both end parts of the web part 4 are joined at approximately right angles to the flange parts 3, the intermediate product of which the thickness of the flange parts 3 and web part 4 are approximately same as the product is formed. And also the intermediate product is rolled in the thickness direction after convex parts 3f and concave part 3g are formed in the tip part 8 of each flange part 3 and rough rolling process by which the flatness at the tip of the flange parts 3 is raised and finishing process by which the channel bar with the flange parts vertical to the web part 4 is formed with plural pairs of forming rolls are orderly executed.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention manufactures a channel-shaped member from a billet having a web portion that is flat in cross section and a pair of flange portions that stand up almost perpendicularly to the web portion. Regarding the method.

[Prior Art] The conventional technology for channel members will be explained by taking a channel steel made of stainless steel as an example.

Generally, when manufacturing channel steel using ordinary steel as a material,
The desired final shape of the channel steel was formed by hole hot rolling.

However, metal materials with high deformation resistance, such as stainless steel, especially austenitic stainless steel such as 303304, have a smaller deformability than the ordinary steel, and have low deformation resistance at high temperatures when hot rolled. Seizure is likely to occur. Therefore, when a stainless steel channel is formed using the groove rolling method, there are disadvantages such as the product having many surface defects and early wear of the rolling roll's groove. The method of manufacturing section steel by groove rolling was not a manufacturing method that could be put to practical use as a mass-produced product.

Therefore, conventionally, in order to manufacture channel steel using stainless steel such as 5TLS304, two angles were lined up in parallel and butt welded instead of using the groove rolling method, which is very inefficient. In reality, a manufacturing method is adopted in which the unnecessary portions 2 of the weld beads formed on the front and back sides are removed by cutting to manufacture channel steel.

In addition, methods for manufacturing channel steel made of stainless steel by hole rolling have been developed from various angles, but closed hole rolling has problems such as wear of the rolling caliber and high cost. On the other hand, in the open-hole rolling process, the end surface of the flange portion of the channel steel is not flat when viewed in a cross section perpendicular to the length direction, but has a mid-height curve. The reason for this is that when the flange part is groove-rolled, the flange part is strongly pressed in the thickness direction by the rolling rolls, and the excess thickness flows to the tip surface of the flange part and bulges out to a medium height.

If the end surface of the flange portion is rounded in this manner, the length of the flange portion will vary, and when the channel steel is butt welded to another member, the buttability and size and shape are not good. Therefore, it is not preferable for modern welding work. Furthermore, when used as a building material, it is not preferred due to its decorative nature. Therefore, in groove rolled channel steel, the tip of the flange portion of the channel steel is purposely cut off with a cutter to flatten the tip surface and improve the dimensions.

For this reason, channel steel that is cut with a flat end face is disadvantageous in terms of yield and price compared to channel steel that has a rounded end face.

[Problems to be Solved by the Invention] Conventionally, stainless steel channel steel has been manufactured despite the fact that productivity is poor and the cost is extremely high. In recent years, there has been an increase in demand for stainless steel channel steel as construction materials and decorative materials, and the flange part There has been a strong demand for the development of a method for manufacturing stainless steel channel steel that is inexpensive and has good dimensional accuracy.

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned drawbacks of the conventional art. That is, the present inventors believe that austenitic stainless steel has a lower deformability than other steel types, and when hot rolled, has high deformation resistance at high temperatures and is prone to seizure.
This study takes into consideration the factors that cause a large difference in roll circumferential speed during groove rolling, which tends to cause seizure in the flange portion, and the factor that causes the end surface of the flange portion to become rounded.

That is, the method for manufacturing a channel member according to the present invention includes 1. By groove rolling, the wall thickness of the flange part and the web part is the same as the product dimensions, and the cross-sectional shape of the pair of flange parts is inclined outward with respect to the perpendicular line, and the web part is made into the flange part. The intermediate product has a convex shape that protrudes to the side, the center part is flat, and both ends of the web part are connected to the flange part at almost right angles.At the same time, each flange part is formed at the φ bending stage or the final stage of forming the intermediate product The cross-sectional shape of each tip end face is made into a concave shape with a mid-high portion in the thickness direction, and after making the concave shape, at least the tip end of each flange portion is rolled in the thickness direction, and by such rolling, the mid-high portion and the concave shape are almost offset. It is characterized by being divided into two processes: a rough rolling process in which adjustments are made to increase the flatness of each end face of the flange part, and a finishing process in which the convex-shaped web part of the intermediate product is flattened by forming rolls. It is.

The rolled material used in the method of the present invention means a metal body having a predetermined cross section and a predetermined length that can be plastically deformed. The material may be, for example, stainless steel, carbon steel, titanium, titanium alloy, or the like.

In the method of the present invention, in the rough rolling step, an intermediate product is formed from a rolled material such as a billet by groove rolling, and during forming, a plurality of intermediate products are arranged parallel to each other and at least one of which is rotated by a drive device. A set of double rolling rolls is used, and in order to reduce the difference in roll circumferential speed at the flange part, the flange part is inclined outward with respect to the perpendicular line, and a predetermined pass schedule, for example, Fig. 1 (1) to (6) is applied. Rough rolling, usually hot rolling, and warm rolling are performed according to the pass schedule shown in .

As mentioned above, in the rough rolling process, the flange portion of the intermediate product needs to be inclined with respect to the perpendicular line when performing the groove rolling process. The reason for this is to reduce the difference in roll circumferential speed at the flange portion during rolling to prevent seizure at the flange portion as much as possible. The inclination angle is preferably 15 degrees or more and 75 degrees or less outward from the perpendicular.

In this case, the reason why the inclination angle is set to be 75° or less is because if the flange portion opens outward beyond this point, it becomes difficult to form the flange portion at right angles to the web portion in the finishing process.

In the rough rolling process, since the flat portion of the web portion of the intermediate product is flat, the roll circumferential speed difference can be significantly reduced or substantially eliminated in the flat portion.

Therefore, it is advantageous to prevent seizure of the flat portion and to prevent surface flaws on the flat portion. Moreover, since the roll circumferential speed difference can be significantly reduced or eliminated, it is possible to prevent uneven wear on the rolling surface of the roll groove on the roll side, and furthermore, it is possible to prevent uneven wear on the rolled surface of the roll groove. It is relatively easy and advantageous in extending the life of the roll.

Furthermore, the width of the flat portion of the convex web portion of the intermediate product is preferably at least ⅓ or less of the total width of the web portion. The reason for this is that if the web portion is processed to be flat by cold rolling, large work hardening will occur locally at the initial stage of forming, making it impossible to obtain a good flat portion.

In addition, in the groove rolling process involved in the rough rolling process, by forming the connecting part between the flange part and the web part at right angles, a channel steel having an excellent top corner shape can be obtained.

Furthermore, in the finishing process, in the finishing process, a channel-shaped material having a pair of flanges parallel to each other and a flat web part perpendicular to the flange is processed by rolling (cold rolling, hot rolling, etc.). (dip roll processing, hot roll processing).

In this case, in cold rolling, when austenitic stainless steel is used as the workpiece material, austenitic stainless steel has the property of being significantly work hardened by cold working, and the desired amount of processing cannot be obtained in one pass. Considering the difficulty, it is therefore preferable that the number of passes by cold rolls disposed parallel to each other be two or more.

In the method of the present invention, a convex web part is formed in stages in the finishing process to form a flat web part. This prevents scratches from occurring.

In addition, in the finishing process, pinch rollers can be provided before and after the forming rolls as necessary. This improves the biting of intermediate products and prevents the forming rolls from slipping.

[Example] The method of the present invention will be explained below based on one embodiment thereof.

In the rough rolling process according to the method of the present invention, a plurality of sets of double rolling rollers are used, which are arranged parallel to each other and have a predetermined hole shape, at least one of which is rotated by a drive device. Then, intermediate products 2 are sequentially formed from the billet 1 according to the bus schedule shown in FIGS. 1 (1) to (6).

In FIG. 1 (6), 3 is a flange portion inclined outwardly with respect to the perpendicular line P of the intermediate product 2, and 4 is a convex-shaped web portion formed between both flange portions 3; 4 is formed of a central flat portion 4a and an end portion 4b connected to the flange portion 3 at a substantially right angle.

FIG. 2 shows the final double hot rolling rolls for forming the intermediate product 2, which are arranged parallel to each other and whose lower parts are rotated by a drive device (not shown); 10 is the upper roll, and 11 is the upper roll. In the lower driving roll, 12 is a hole pattern symmetrical to the intermediate product 2.

FIG. 3 shows a four-axis rolling mill used at the final stage of the rough rolling process. This 4-axis rolling roll device is for forming an intermediate product 2 into a cross-sectional shape in which the end surface 9 of the tip end 8 of the flange portion 3 is concave.
, a cylindrical rolling roll 22 and a slotted roll 23. FIG. 4 shows a partially enlarged view of the groove 25 of the groove roll 23, and the groove 25 has a bottom surface 25a that bulges toward the opening 25C in cross-sectional shape, and a side surface 25b that widens toward the opening 25c. Motsu.

FIG. 7 is a schematic configuration diagram showing a plurality of sets of forming rolls arranged in series and having a desired roll shape, which are used to cold roll the intermediate product 2 in the finishing process. 5
1 is a pinch roller on the input side, 52 is a pinch roller on the output side,
53 is a string-type roll provided above, 54 is a downward &:
Among the cylindrical rolls provided, 55 and 56 are flat rolls.

By the way, in the manufacturing method according to this example, first, a rough rolling step is performed. In the rough rolling process, the cross section is 50mm
Using a billet 1 of SO3304 with a diameter of 50 mm and a length of 1000 mm, the billet 1 is heated to 1050°C, and then the billet 1 is transferred to a rough rolling roll by a roller (not shown). The flange portion 3 was successively rolled using the bus schedule shown in (6) without seizure.

Then, in the rough rolling process (in the upper roll 10 shown in FIG.
, the lower drive roll 11 is used, thereby the flange portion 3
The wall thickness of the web part 4 is almost the same as the product dimensions, the pair of flange parts 3 are each opened outward at 45 degrees with respect to the perpendicular line P, and both ends of the web part 4 are convex. An intermediate product 2 (see FIG. 1 (6)) was produced in which the portion 4b was directly connected to the flange portion 3 at a substantially right angle, and the width of the central flat portion 4a was 1 part 4 times the total width of the web portion 4. Here, since the flat portion 4a of the web portion 4' is so flat in the horizontal plane, the roll circumferential speed difference can be significantly reduced or substantially eliminated in the flat portion 4a. Therefore, seizure of the flat part 4a is prevented.
This is advantageous in preventing surface flaws on the flat portion 4a. Moreover, on the roll side, the roll circumferential speed difference can be significantly reduced or eliminated, so uneven wear on the rolled surface of the groove of the rolls 10 and 11 can be prevented, and furthermore, even if the roll is re-adjusted after wear, the roll will wear unevenly. This is easier than in the case of doing so, and is advantageous in extending the life of the O-ru 10.11.

Further, at the end of the rough rolling process, the intermediate product 2 was rolled using a 4-axis rolling roll device shown in FIG.

FIG. 5 shows a cross section of the tip 8 of the intermediate product 2 formed by the grooves 25 of the groove rolls 23 in the final stage of rolling. As shown in FIG. 5, the distal end portion 8 of the flange portion 3 is formed with a middle portion 3f that bulges out in the thickness direction, and a concave portion 3Q having an arcuate concave shape on the end surface side.
-Next, the thickness of the tip 8 of the flange portion 3 is adjusted. In this case, a four-wheel milling roll device having basically the same configuration as the four-wheel rolling mill shown in FIG. 3, or a milling roll device similar to the two-wheel rolling mill shown in FIG. 2 is used. However, this four-wheel rolling device differs in that instead of the grooved roll 23, it has a groove for adjusting the thickness of the tip end 8 to be uniform.

When such a thickness adjustment process is carried out, as can be understood from FIG. 6, the middle high part 3f is rolled and crushed in the thickness direction, and the excess material flows toward the concave part 3g and plastically deforms, so that the middle high part 3f and the concave shape are The flatness of the end surface 9 of the flange portion 3 is increased by offsetting the portion 3Q.

Roughly speaking, the corner 9C of the end surface 9 of the flange portion 3 is substantially 9
It becomes 0 degrees.

After completing the thickness adjustment in this way, a finishing process is carried out.

In the finishing process, the intermediate product 2 is held between the pinch rollers 51 shown in FIG. .56 Insert the intermediate product 2 between the holes. As a result, the web portion 4 having an upward convex shape is formed in stages and is made flat without any change in thickness. As a result, a channel steel having two flange portions 3 shown in FIG. 10 that were perpendicular to the web portion 4 and parallel to each other was manufactured.

In this example, a heat treatment process, a straightening process, and a pickling process are then performed in this order.

In the heat treatment process, the channel steel is placed on a conveyor roller and moved through a heat treatment furnace to be heated to about 1150° C., and when it exits the heat treatment furnace, cooling water is sprayed onto the channel steel to perform a water blunting treatment.

In the straightening step, the channel steel is placed on a conveyance roller and passed through the straightening roller.

In the pickling process, acid is sprayed onto the groove-shaped material placed on the conveying roller to pickle it, and then water is sprayed onto the groove-shaped material to perform water washing.

[Effects of the Invention] As described above, in the method of the present invention, by producing an intermediate product having the cross section as described above in the rough rolling process, it is possible to produce an intermediate product having a cross section as described above in the rough rolling process. Even a rolling material made of a metal material which is very susceptible to seizure when rolling can be rough rolled while suppressing the occurrence of surface flaws.

Further, the method of the present invention can improve the flatness of the end face of the tip of the flange portion of the channel member, and therefore, the dimensional accuracy of the flange portion can also be improved by improving the flatness. Therefore, a channel-shaped material with excellent butt weldability and aesthetic appearance can be obtained.

Further, in the method of the present invention, side pressure is applied to the flange portion while the flange portion is inclined outward at a predetermined angle, for example, 15° or more with respect to the perpendicular line, so that galling of the flange portion can be avoided as much as possible.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIGS. 1 (1) to (6)
is a block diagram showing the pass schedule for manufacturing intermediate products from billets, Fig. 2 is a front view showing the final rolling roll shape in the rough rolling process, Fig. 3 is a front view of the 4-axis rolling roll device, and Fig. 4 is the hole configuration. FIG. 5 is a sectional view of the main part of the mold roll, and FIG. 5 is a sectional view of the tip of the flange part. Fig. 6 is a cross-sectional view of the flange portion whose thickness has been adjusted, Fig. 7 is a schematic configuration diagram showing the rolls and pinch rollers used in cold rolling as a finishing process, and Fig. 8 is a cross-sectional view of the flange portion after adjusting the thickness. Fig. 9 is a front view of a flat roll used for cold rolling, and Fig. 10 is a cross-sectional view of the channel steel subjected to the finishing process. . In the figure, 2 shows the intermediate product, 3 shows the flange part, and 4 shows the web part. Patent applicant: Aichi Steel Co., Ltd.

Claims (3)

[Claims] (1) In manufacturing a channel member formed by a pair of flange portions that are substantially parallel to each other and a web portion that is substantially perpendicular to the flange portions, at least one of the flange portions is arranged parallel to each other and rotated by a drive device. A rolled material heated to a predetermined temperature is subjected to groove rolling using multiple sets of double rolling rolls each having a predetermined groove shape, and the shape of its cross section is adjusted so that the pair of flanges are perpendicular to each other. The web part is inclined outward and has a convex shape protruding toward the flange part, the central part of which is flat, both ends of the web part are connected to the flange part at almost right angles, and the flange part and the web part are flat. An intermediate product whose wall thickness is almost the same as the product dimensions is molded, and at the later or final stage of molding the intermediate product, the cross-sectional shape of each end face of each flange part is shaped into a concave shape with a mid-height part in the thickness direction. Rough rolling in which, after forming a concave shape, at least the tip of each flange portion is rolled in the thickness direction, and this rolling substantially cancels out the middle and high portions and the concave shape to increase the flatness of each tip surface of the flange portion. Even with the process and multiple sets of forming rolls arranged parallel to each other,
a finishing step of forming a convex-shaped web portion of the intermediate product to form a channel member having a flange portion and a flat web portion that are perpendicular to the web portion and substantially parallel to each other; A method for manufacturing a channel-shaped material characterized by: (2) The method for producing a channel-shaped member according to claim 1, wherein in the rough rolling step, the inclination angle of the flange portion of the intermediate product is inclined outward by 15 to 75 degrees with respect to the perpendicular line. (3) In the rough rolling step, the width of the flat portion formed on the convex web of the intermediate product is 1/3 or less of the total width of the web portion. manufacturing method.