JP2554462B2 - Method for producing stainless angle iron - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention combines a hot hole rolling process and a cold forming process to form a stainless steel billet or a plate material that is difficult to work and is easily seized. The present invention relates to a method for manufacturing angle steel.

(Problems to be Solved by Prior Art and Invention) In general, when manufacturing stainless angle iron, the final shape was formed by hot hole rolling. However, stainless steel, especially austenitic stainless steel such as SUS304, has a large deformation resistance at high temperature, and since seizure easily occurs, the product has many surface defects when formed in the hot hole rolling. In addition to the occurrence, there is a defect that the rolling rolls are worn early.

Further, stainless angle steel is required to have various sizes, and in the conventional hot hole rolling, the rolling rolls are replaced each time, and it is necessary to prepare a large number of rolling rolls. , Spending a lot of time exchanging rolling rolls.

Further, in recent years, along with the increasing demand for stainless chevron as a building material and a decorative material, there has been a strong demand for the development of a method for inexpensively manufacturing the chevron.

(Means for Solving Problems) In order to meet the problems and demands of the above-mentioned conventional techniques, the present invention has revealed that, as a result of various studies, the present inventors have found that stainless steel has poor deformability as compared with other steel types, and Due to the material factors such as high deformation resistance at high temperature, which easily causes seizure, and a large difference in peripheral speed due to the depth of the hole shape of the rolling roll during rolling, seizure is likely to occur. In consideration of the factors and the factors described above, when hot rolling is applied to a rolling material, which is a stainless steel material that is difficult to work and is easy to seize, when the stainless angle iron is manufactured, It is better to divide it into a first step of making the depth shallower and a second step of bending by using a deep hole type roll with a large peripheral speed difference in the cold, which is unlikely to cause seizure. The following is the summary of the It is as follows.

When the stainless steel chevron is manufactured by forming the rolling material, the rolling rolls are arranged in parallel with each other, and at least one of them is rotated by a driving device to form a predetermined roll shape, which is heated to a predetermined temperature. The rolling material is rolled to form chevron steel, and the two sides that form the chevron are straight, and a right-angled protrusion is formed at a location corresponding to the corner connecting the sides, and the back side of the protrusion is further formed. A first step of forming a recess having a radius of curvature at least twice the plate thickness, and forming an intermediate product in which the thickness of two sides is the same as the product dimension;
After cooling the intermediate product obtained in the step to a cold temperature region, a plurality of sets of cold forming rolls arranged in parallel to each other are used to form at least 2 parts of the intermediate product having two linear sides. It is characterized in that it comprises a second step of forming a mountain-shaped steel which is cold-formed by a pass or more, and whose corners are right angles and whose two sides are right angles.

(Maximum feature of the present invention) As described above, the present invention provides hot rolling when a stainless steel chevron is manufactured by subjecting a rolling material, which is a stainless steel that is difficult to work and is easily seized, to hot bending. A first step of making the hole shape of the roll of the die rolling shallow and processing, and a bending forming process using a hole roller of a deep hole shape with a large peripheral speed difference in the cold where seizure hardly occurs. The greatest feature is that it is divided into steps.

(Structure of the first step) Therefore, since the first step of the present invention is performed hot, if the peripheral speed difference of the rolling roll on the side of the angle steel is large, seizure occurs on the side, which is prevented. For this reason, the intermediate product is formed by rolling rolls which are arranged so that two sides thereof are linear and at least one of which is rotated by a driving device and which has a predetermined hole shape.

Further, in cold forming, since there is little overhang of meat and it is difficult to form, in the present invention, in the first step of hot rolling, it is possible to form sufficient overhang of meat in the corners of the angle steel. , In order to pre-form the angled corners of the angle steel, it was formed in a shallow hole shape so as to form a right-angled protrusion at a position corresponding to the angled corner where the sides are connected. .

Moreover, when cold rolling is performed, work hardening locally occurs at the initial stage of forming, and a corner portion of the angle steel cannot be obtained. Therefore, in order to prevent work hardening in such cold working, In the first step, that is, during hot rolling)
A concave portion having a radius of curvature of at least twice the plate thickness is formed on the back surface side of the protruding portion.

(Structure of the second step) In this second step, the intermediate product obtained by the hot rolling of the second step is used in a cold state where seizure hardly occurs, and a deep hole type roll having a large peripheral speed difference is used. Then, the bending process is performed.

Since this second step is to perform cold forming, it becomes difficult if the bending amount in one pass is large, and
Due to the increase in the processing force, local processing defects are likely to occur. Therefore, in order to prevent the intermediate product obtained in the first step from being easily caught in the roll and to cause local processing flaws, a plurality of sets of cold forming rolls arranged in parallel to each other are used to form a straight line. A stainless chevron-shaped steel was formed by subjecting the intermediate product having two sides to a stepwise cold forming of at least two passes or more.

Also, in order to prevent differences in thickness and defects in the product, and to make the thickness of both sides of the angle steel uniform, and to ensure that the product angle steel has no defects, multiple sets of cold With the intermediate roll, stepwise bending is performed with the corner formed in the first step and the recess on the back surface as the starting point, and the corner is outward, and the corner is formed into a right angle by the second step. In addition, the angle steel is formed so that the two sides have a right angle shape.

Further, in the cold roll processing of the second step, as described above, in order to improve the biting of the intermediate product and prevent the slip of the forming roll, the pinch rollers may be provided before and after the cold roll as necessary. Can be provided.

(Operation and Effect) The operation and effect of the present invention are as follows.

First, in the first step, when a stainless steel chevron is manufactured by forming a rolling material, the rolling rolls are arranged in parallel with each other, and at least one of them has a predetermined hole shape rotated by a driving device. Rolling is performed on a rolling material heated to a predetermined temperature to form a chevron with two straight sides and right-angled protrusions at the corners connecting the sides. Further, a concave portion having a curvature radius of at least twice the plate thickness is formed on the back surface side of the protruding portion,
An intermediate product is formed in which the thickness of the two sides is the same as the product size.

Therefore, when the intermediate product is formed, since it is rolled by the rolling rolls whose two sides are linear, the peripheral speed difference is small, and seizure may occur on the side of the intermediate product. There is no.

Further, since the process is divided into two and the subsequent process is the cold working process, since the protrusions that are substantially orthogonal to each other are formed during the hot rolling of the first process, the cold forming causes less overhang of the meat and However, it is possible to form a product in which meat is sufficiently overhanged at the projecting portion that hits the corner of the product.

Further, in the present invention, in the hot rolling step of the first step,
Since a concave portion having a radius of curvature of at least twice the plate thickness is formed on the back surface side of the protruding portion, work hardening occurs locally at the initial stage of forming in cold roll working, whereas the corner portion does not work hardening. A good intermediate product can be obtained.

Next, in the second step, the intermediate product having two straight sides is cold-formed by at least two passes or more by using a plurality of sets of cold-forming rolls arranged in parallel with each other, and a corner angle is obtained. The angle portion is formed at right angles and the two sides are formed into a right angled angle steel.

Therefore, in the case of cold forming, if the bending amount in one pass is large, the biting is bad and the amount of processing increases, so that local processing flaws are likely to occur, so the second step of the present invention Then, since it was decided to mold in stages with 2 passes or more,
It became easier to bite into the roll, and local processing flaws did not occur on the product.

In addition, as described above, the corners are stepwise at right angles, and
Since the angle steel having the right-angled sides is formed by bending, it is possible to obtain the angle steel having a uniform thickness without flaws on both sides.

According to the present invention, when a rolling material which is stainless steel is molded to produce stainless angle steel, the first step of working by making the hole shape of the roll of hot hole rolling a shallow depth, and the process of baking By using a deep hole type roll with a large peripheral speed difference in the cold state that does not occur, and by dividing it into the second step of bending and forming, a stainless rolled material that is difficult to work and is easy to bake is used. Also, the beautiful skin without burning,
Moreover, it is possible to manufacture an angle steel in which two sides have a right angle shape without changing the thickness of the intermediate product.

Moreover, since it is not necessary to prepare and place a large number of rolls having different hole shapes depending on the size of the product angle steel, the same angle steel is used as compared with the conventional method for manufacturing angle steel by only hot hole rolling. In addition, according to the present invention, it can be manufactured at low cost, can meet the demand as a building material and a decorative material, and has high practicality.

(Embodiment) Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 4 is a cross-sectional view of a stainless steel billet, FIG. 1 is a front view showing a state of being rolled by a hot final rolling roll in the first step, and FIGS. It shows a cross section of the intermediate product obtained in the first step.

Further, FIG. 2 is a conceptual diagram showing a roll and a pinch roller used for the cold roll working in the second step, and FIG. 3 is a state in which the cold roll working is performed using the convex roller and the concave roller. FIG.

1 is a billet, 2 is an intermediate product, 3 and 4 are sides 5
Is a corner portion, 6 is a protruding portion, and 7 is the protruding portion 6
Is a concave portion on the back surface side.

8 and 9 are the upper and lower rolls of the hot final rolling in the first step, and 10 is the hole type thereof.

11 and 12 are pinch rollers used in the second step, and 13 and 14 are convex and concave rolls used in the second step. Moreover, 20 is the product angle iron.

As a rolling material, as shown in Fig. 4, the cross section is 50
A billet 1 of JIS-SUS304 austenitic stainless steel having a corner and a length of 1000 mm was used. When this billet 1 was hot-rolled, it was heated to 1050 ° C. in advance.

In the first step, the billet 1 is rolled with the rolling rolls 8 and 9 in which at least one of them is formed in parallel with each other and at least one of which is rotated by a driving device, and the angle steel 20 is formed. The two sides 3 and 4 are linear, and a projection 6 is formed at a right angle at a position corresponding to a corner 5 where the side 3 and the side 4 are connected to each other. Further, the back surface side of the projection 6 has a radius of curvature. A recess 7 having a thickness twice or more the plate thickness was formed, and an intermediate product 2 in which the thickness of the two sides 3 and 4 was the same as the size of the product 20 was molded.

Unlike the hot rolling step, the next second step is to cool the intermediate product to room temperature and then guide the pinch rollers 11 and 12 provided in front and rear of the intermediate product so as to be arranged in parallel with each other. And a plurality of sets of cold forming rolls constituted by concave rolls 13 and 14,
At least two passes or more were cold-formed on the sides 3, 4 to form an angle steel 20 in which the corner portion 5 had a right angle and the two sides 3, 4 had a right angle shape.

In this embodiment, when the rolling material 1 made of stainless steel is hot-rolled to manufacture the stainless chevron steel 20, the depth of the hot-roll rolling rolls 8 and 9 is made shallow. Difficult-to-workability by dividing into the first step of processing and the second step of bending forming using deep hole type rolls 13 and 14 with a large peripheral speed difference in the cold without seizure. Even if the rolled stainless steel material 1 that is easy to burn is used, the angle steel 20 in which the two sides 3 and 4 have a right-angled shape with a clean skin without burning and without changing the thickness of the intermediate product 2 is obtained. I was able to manufacture it.

In addition, since it is not necessary to prepare and place a large number of rolls 8, 9 or 13, 14 having different hole shapes 10 etc. according to the size of the product angle steel 20, the angle steel manufactured by conventional hot hole rolling only. Compared with the manufacturing method of, the angle steel 20 is also obtained, in the case of the present embodiment, it can be manufactured at low cost, and it is possible to obtain a variety of types of clean stainless steel angle steel. Can meet the requirements of.

[Brief description of drawings]

FIG. 1 is a front view showing a state where rolling is performed by the hot final rolling roll in the first step, and FIG. 2 shows rolls and pinch rollers used for cold rolling in the second step. FIG. 3 is a conceptual diagram, and FIG. 3 is a front view showing a state in which cold rolling is performed using a convex roller and a concave roller.
4 is a cross-sectional view of a stainless steel billet,
FIG. 5 shows a cross section of the intermediate product obtained in the first step. 1: Billet, 2: Intermediate product, 3, 4: Side, 5: Corner, 6: Projection, 7: Recess on the back side of the projection 6, 8 and 9: Final hot rolling in the first step Upper roll and lower roll, 10: its hole type, 11, 12: pinch rollers used in the second step, 13, 14: convex and concave rolls used in the second step, 20: chevron as a product steel.

Claims (1)

(57) [Claims] 1. When a stainless steel chevron is manufactured by forming a rolling material into a rolling material, rolling rolls are provided in parallel with each other, and at least one of them is rotated by a driving device to form a predetermined rolling die. Rolling is performed on a rolling material heated to a temperature to form a chevron-shaped steel with two straight sides and right-angled protrusions at locations corresponding to the corners connecting the sides. A first step of forming an intermediate product in which a concave portion having a radius of curvature at least twice the plate thickness is formed on the back surface side of the projecting portion and the thickness of two sides is the same as the product dimension; After cooling the intermediate product obtained in 1. to a cold temperature region, at least 2 passes with respect to the intermediate product having two linear sides by a plurality of sets of cold forming rolls arranged in parallel with each other. Performed the above cold forming, the corners were right angles, and Method for producing a stainless angle iron, characterized in that and a second step of sides forming the angle irons at right angles shape.