JPH0798203B2 - Angle steel manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing an angle steel from a billet or a flat steel by combining a hot hole rolling process and a cold roll forming process.

(Prior Art) In general, when manufacturing angle steel using a material such as ordinary steel,
It was formed into a chevron steel having a desired final shape by hot-rolling. However, among stainless steels, austenitic stainless steels such as SUS 304 have a smaller deformability than the above steels, have a large deformation resistance at high temperatures, and are prone to seizure. There are drawbacks such as the occurrence of a large amount and the hot hole rolling rolls being worn early.

In addition, angle steel formed by hot hole rolling is
It is cut into a predetermined length and then the internal stress generated by working is removed, and after solution heat treatment is carried out to form a solid solution of the carbide precipitated in the hot hole rolling process, straightening is performed and the end is cut. Have been shipped.

However, the solution heat treatment described above causes the long chevron steel to be deformed and to be largely bent, which requires a great deal of artificial work in the correction of the post-process.

(Problems to be solved) As described above, in the conventional manufacturing method of the stainless angle iron, a lot of surface flaws are generated on the product and a great deal of manpower is required for the correction after the heat treatment, resulting in poor productivity and cost. It was also expensive.

In recent years, along with the increasing demand for stainless angle steel as a building material and a decorative material, there has been a strong demand for the development of an inexpensive method for manufacturing stainless angle steel.

(Means for Solving Problems) The present invention has been made in view of the above-mentioned drawbacks in the conventional hot hole rolling, and the present inventors have a small deformability such as austenitic stainless steel, In addition, there is a material factor that deformation resistance at high temperature is high and seizure easily occurs, or there is a large difference in roll peripheral speed in the flange portion during hot hole rolling, resulting in a flange portion. Even if there is a forming factor that seizure easily occurs, the present invention provides a method for manufacturing angle steel by hot-rolling using a hot hole rolling process. An intermediate product in which the thickness of the pair of flanges is the same as the product size, the cross-section is straight, and the protrusion is perpendicular to the location corresponding to the apex and the recess is formed on the back surface of the protrusion. The first step of forming the Immediately after the work, the second step in which the intermediate product in the coil state is solution-heat-treated, and the pair of linear flanges of the intermediate product in a cold forming roll are cold rolled into mutually perpendicular flanges. It is characterized in that it is divided into three steps, a third step for processing.

Further, according to the present invention, a rolled material such as a billet and a flat steel is formed in parallel with each other by forming an intermediate material having a cross section as described above by hot hole rolling, and at least one of them is rotated by a driving device. Using a rolling roll,
In order to reduce the roll peripheral speed difference in the flange portion, the pair of flange portions are linear.

In addition, the present invention prevents the deformation and bending due to the solution heat treatment by immediately winding and coiling the intermediate product formed by the hot hole rolling process, and facilitates the supply and removal of the material in the straightening. It is a thing.

Further, according to the present invention, when the angle steels having mutually perpendicular flange portions are cold roll formed from the intermediate product, the number of passes by the cold forming rolls arranged in parallel is at least 2 or more, and the linear shape is obtained. The flange part of is formed stepwise, and the pair of flange parts are at right angles to each other, and it is possible to prevent the intermediate product from partially changing its thickness or causing flaws in the product due to improper processing. is there.

Further, in the hot hole rolling process, the pair of flange portions of the intermediate product are made linear in order to reduce the roll peripheral speed difference in the flange portion during rolling and prevent seizure from occurring in the flange portion. is there.

Furthermore, the reason why the right angled protrusion is formed at a position corresponding to the open-closed corner where the pair of flanges of the intermediate product are connected is that it is difficult to form meat during cold roll forming, which makes forming difficult. In addition, it is necessary to form a concave portion on the back surface side of the projecting portion whose radius of curvature is at least twice the thickness of the flange portion
If it is smaller than twice, when the flange portions are processed at right angles to each other in the cold roll forming process, work hardening locally occurs at the initial stage of forming, and a good apex angle portion cannot be obtained.

In the cold roll forming process, pinch rolls are provided before and after the cold forming rolls as needed.
This improves the biting of the intermediate product and prevents slipping of the cold forming roll.

(Example) Hereinafter, the present invention will be described based on an example thereof.

The present invention initially uses a plurality of sets of rolling rolls for hot-hole rolling, which are arranged in parallel with each other and at least one of which is rotated by a driving device, to form an intermediate product from a billet. It is what is molded. 1 is a billet, 2 is a pair of flange portions 3 shown in FIG. 1 which are linear, and a protrusion 6 which is perpendicular to a portion corresponding to an apex angle portion 5 where the flange portions 3 and the flange 3 are connected, Protrusion 6
This is an intermediate product in which an arcuate concave portion 7 is formed on the back surface side of.

FIG. 2 shows a final rolling roll, which is arranged in parallel with each other for forming the intermediate product 2 and has a predetermined hole shape whose lower portion is rotated by a driving device (not shown), and 8 is an upper roll. Here, 9 is a drive roll and 10 is a hole type.

FIG. 3 is a schematic view showing a plurality of sets of forming rolls arranged in parallel with each other and having a desired roll shape, which are used for cold roll forming the intermediate product 2, and 11 is a pinch on the inlet side. Rolls, 12 are pinch rolls on the exit side, 13 are V-groove rolls having V-grooves provided above, and 14 are chevron rolls provided below.

Then, in order to manufacture 50 × 50 × 3 × 4000 mm equilateral angle steel, first, a SUS 304 billet having a cross section of 50 squares and a length of 1000 mm is heated to 1050 ° C., and then the billet 1 is rolled by a roll (not shown) 8.9. The billet 1 is sequentially processed, and the wall thickness of the flange portion 3 is 3 mm which is the same as the product dimension without seizing the flange portion 3 and the pair of flange portions 3 are linear and A protrusion 6 is formed at a right angle at a position corresponding to the apex angle portion 5 connecting the portion 3 and the flange portion 3, and a concave portion 7 having a curvature radius of 2.5 times the plate thickness of the flange is formed on the back surface side of the protrusion 6. The formed intermediate product 2 was produced.

Then, the intermediate product was immediately wound up, coiled, charged into a heating furnace, and subjected to solution heat treatment at 1050 ° C. for 1 hour. In the present invention, the intermediate product having a thickness of 3 mm was neither deformed nor bent by winding the intermediate product and heat-treating it in a coiled state.

Then, the intermediate product 2 which has been subjected to the heat treatment in the above-mentioned step is held by a pinch roll 11 and is caught between a V-groove roll 13 having V-grooves arranged above and below and a chevron roll 14 to form a flange portion 3 Was formed stepwise, and an angle steel having flange portions 3 at right angles to each other was manufactured without changing the thickness.

(Effects of the Invention) As described above, the present invention produces an intermediate product having a straight horizontal cross section in the hot hole rolling process, and thus has a poor deformability like austenitic stainless steel and is extremely hard to burn. Hot-rolling can be performed without surface flaws even on steels that are prone to sticking, and after hot-rolling, the coiled intermediate product is immediately loaded into the heating furnace after winding. In order to prevent deformation and bending of the intermediate product and save energy, the solution is subjected to solution heat treatment and has flanges that are perpendicular to each other without changing the thickness of the intermediate product by cold roll forming. The angle steel can be produced, and the method of the present invention can be produced at a lower cost than the conventional method for producing the angle steel, and thus the method of the present invention has high practicality.

[Brief description of drawings]

The drawing shows one embodiment of the present invention. Fig. 1 shows a cross section of an intermediate product, Fig. 2 shows a final rolling roll shape, and Fig. 3 is used for cold forming. FIG. 4 is a schematic view showing rolls and pinch rolls, and FIG. 4 shows V-groove rolls and chevron roll shapes used for cold roll forming. FIG. 5 shows a billet. 1: Billet, 2: Intermediate product, 3: Flange 5: Corner, 6: Projection, 7: Recess, 8: Upper roll, 9: Lower roll, 10: Hole type 11, 12: Pinch roll, 13 : V groove roll 14: Yamagata roll

Claims (1)

[Claims] 1. A double-rolling roll, which is arranged in parallel with each other and at least one of which is rotated by a driving device and which has a predetermined hole shape, is used to perform a hole-type hot rolling process on a rolling material heated to a predetermined temperature. The pair of flanges are linear, and a protrusion is formed at a right angle at a position corresponding to the apex corner where the flange and the flange are connected to each other. An intermediate product having a shape in which a concave portion having a radius of curvature of at least twice the plate thickness of the flange portion is formed on the back side and the thickness of the flange portion is the same as the product dimension is molded to obtain the intermediate product. Immediately and continuously, a first step, then a second step of performing solution heat treatment in a coil state and then cooling, and then a plurality of sets of cold forming rolls arranged in parallel to each other, A pair of products franc Part at least two passes or more, cold-rolled forming process, the manufacturing method of the angle iron, characterized in that and a third step of finishing the pair of flange portions mutually perpendicular angle iron.