JPS61137602A - Manufacture of angle - Google Patents

Abstract

PURPOSE:To obtain a stainless-steel angle free from surface flaw by cold forming a hot caliber-rolled intermediate product, whose cross section is approximately flat and has recessed and projected parts respectively at the inner and outer sides of its central part, into a right-angled chevron shape between the rolls of projected and recessed types. CONSTITUTION:An intermediate product 2 having two sides 3, 4, flat and equal in thickness to the sides of a product, and a recessed part at the inside of its central part and a projected part 5 at the outside, is manufactured by providing calibers 10 to the rolling rolls 8, 9 of a final stage of hot rolling. In cold rolling, the product 2 is fed in-between a projected type roll 13 and a recessed type roll 14 to obtain an angle 20 having right-agled two sides 3, 4. In this way, a stainless-steel angle free from surface flaws can be inexpensively manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method of manufacturing angle steel from billet or plate material by combining hot hole rolling and cold forming.

(Prior Art and Problems to be Solved by the Invention) Generally, when manufacturing angle steel, the angle steel is formed into a desired final shape by hot hole die rolling.

However, among stainless steels, austenitic stainless steels such as 5OS304 have high deformation resistance at high temperatures and are prone to seizure, so when formed by hot hole rolling, the product may have surface flaws. There were disadvantages such as a large number of occurrences and premature wear of the rolling rolls.

In addition, angle iron is required to be of various sizes, and in conventional hot hole rolling, the rolls are replaced each time, requiring a large number of rolls and spending a lot of time replacing the rolls. See you again.

Furthermore, in recent years, demand for stainless steel angle steel has been increasing as a building material and decorative material, and there has been a strong demand for the development of an inexpensive method for producing stainless steel channel steel.

(Means for Solving the Problems) The present invention was made in view of the above-mentioned drawbacks in conventional hot hole rolling. In addition, the present invention has been developed by taking into consideration the material factors such as high deformation resistance at high temperatures and the tendency to cause seizure, and the forming factor such as the large difference in roll circumferential speed during rolling and the tendency to cause seizure. The manufacturing method of angle iron is made by hot rolling in a hole shape so that the wall thickness on two sides is almost the same as the product dimensions, the cross section is almost flat, and the protrusion is almost perpendicular to the corner part. A process of forming an intermediate product in which four parts with a radius of curvature of at least twice the plate thickness is formed on the back surface of the protruding part, and a process of processing two substantially flat sides of the intermediate product using a cold-open forming roll. In addition, it is characterized by being divided into two processes: one in which the corners are right angles, and the other two sides are right angles.

The present invention uses rolling rolls arranged parallel to each other, at least one of which is rotated by a drive device, to form an intermediate material having the above-mentioned cross section from a rolled material such as a billet by groove rolling. In order to reduce the difference in circumferential speed of the rolls on the sides, the two sides are made almost straight. Further, the present invention provides that when cold rolling an angle steel having a right angle corner connecting sides and two right angles from the intermediate product, the bending amount in one bath is large. Considering that it is difficult to get caught in the rollers and that local machining is likely to occur due to increased machining force, the number of baths using cold rolls arranged parallel to each other should be set to at least two baths or more. , the two sides are formed in stages, the corners are right angles, and the two sides are right angles, and the present invention prevents the intermediate product from partially changing in thickness due to improper processing, and the product. This prevents scratches from occurring on the surface.

In addition, the reason why the two sides of the intermediate product are made almost straight in the hot hole rolling process is to reduce the difference in roll circumferential speed at the sides during rolling and to prevent seizure from occurring on the sides. be.

Furthermore, the reason why a nearly right-angled protrusion was formed at a location corresponding to the corner where two sides of the intermediate product are connected is because molding is difficult in cold-open molding because there is little protrusion of the meat. The reason for forming a concave part on the back side of the protruding part is that if the radius of curvature is less than this, when two sides are machined at right angles during cold rolling, localized parts may be formed in the early stage of forming. This is because work hardening occurs and good corner parts cannot be obtained.

Furthermore, in cold rolling, pinch rollers are provided before and after the cold rolling as necessary. This improves the biting of intermediate products and prevents the forming roller from slipping.

(Example) The present invention will be explained below based on one embodiment thereof.

The present invention first uses a plurality of sets of rolling rollers arranged parallel to each other and having a predetermined groove shape, at least one of which is rotated by a drive device, to roll a billet into a fifth roll.
The intermediate product shown in the figure is molded. 2 is a billet, and 2 is a protrusion 6 whose two sides 3.4 are straight and which is perpendicular to the corner 5 where sides 3 and 4 connect.
This is an intermediate product in which a recess 7 is formed on the back side of the protrusion 6.

FIG. 1 shows the final rolling rolls for forming the intermediate product 2, which are arranged parallel to each other and have a predetermined hole shape whose lower part is rotated by a drive device (not shown), and 8 is an upper roll. 9 is a driving roller, and 1o is a hole.

FIG. 2 is a schematic diagram showing a plurality of sets of forming rollers arranged parallel to each other and having a desired roll shape, which are used to cold roll the intermediate product 2, and 11 is a pinch roller on the entry side. , 12 is a pinch roller on the exit side, 13 is a convex roller provided above, and 14 is a concave roller provided below.

First, a billet 1 with a cross section of 50 squares and a length of 1000 mm is heated to 1050°C, and then the billet 1 is transferred to a rolling roller by a roller (not shown), and the billet 1 is sequentially processed, and the two sides 3.4 are baked. The wall thickness of side 3 and side 4 is the same as the product dimensions without causing any side 3 and side 4, and side 3 and side 4 are linear, and the corner where side 3 and side 4 are connected is Producing an intermediate product 2 in which a right-angled protrusion 6 is formed at a location corresponding to the part 5, and a recess 7 whose radius of curvature is at least twice the thickness of sides 3 and 4 is formed on the back side of the protrusion 6. did.

Next, in the above step, the formed intermediate product 2 is held between pinch rollers 11, and convex rollers 13 disposed above and below,
By biting between the concave rollers 14, the sides 3 and 4 are formed into a right-angled shape in stages, so that the corner 5 is right-angled and the two sides 3.4 are right-angled without changing the thickness. A channel steel 20 was manufactured.

In addition, when manufacturing the intermediate product 2, as mentioned above, the side 3
Also, the same effect as described above can be obtained even if the sides 3 and 4 are inclined by about 10° toward the recess 7 as shown in FIG. 6, instead of forming the sides 4 in a straight line.

(Effects) As described above, the present invention is capable of producing an intermediate product having a substantially flat cross section, a recessed portion inside the center portion, and a protruding portion perpendicular to the outside through hot hole rolling processing. By,
It has poor deformability like austenitic stainless steel,
In addition, even steel that is extremely prone to seizure can be hot rolled without surface flaws, and intermediate products can be processed even in cold rolling by using a combination of convex rollers and concave rollers. It is possible to produce angle steel with two sides at right angles without changing the thickness, and it does not require a large number of rolls, and can be produced at a lower cost than conventional hot hole rolling. , has high practicality.

[Brief explanation of drawings]

Figure 1 shows the final hot rolling roll shape.
The figure is a schematic diagram showing a roll and a pinch roller used in cold rolling, and FIG. 3 shows the shapes of a convex roller and a concave roller used in cold rolling. FIG. 4 is a cross-sectional view of the billet, and FIG. 5.6 is a cross-sectional view of the intermediate product.

Claims (1)

[Claims] When manufacturing angle steel by hot rolling and cold forming a rolled material, rolling rolls with a predetermined hole shape that are arranged parallel to each other and at least one of which is rotated by a drive device are used to produce angle steel at a predetermined temperature. The two sides that form the angle iron are almost flat by rolling the rolled material heated to
In addition, a nearly right-angled protrusion is formed at a location corresponding to the corner where the sides connect, and a recess with a radius of curvature of at least twice the plate thickness is formed on the back side of the protrusion. An intermediate product whose wall thickness is approximately the same as the product dimensions is formed, and then a plurality of sets of cold forming rolls arranged parallel to each other are used to form at least two approximately flat sides of the intermediate product. 2
1. A method for manufacturing angle iron, which comprises performing cold forming to a degree larger than that of a bus to form an angle iron having right-angled corners and a right-angled shape on two sides.