JPH11124625A - Production of stainless flat steel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable the production of many kinds in small quantities of a thin sheet stainless flat steel good in workability and dimensional precision by forming an austenitic stainless steel strip with a prescribed width to a product sheet thickness by cold forming, thereafter, in this producing line, continuously heating the stainless steel strip with the product sheet thickness to a temp. in a specified range by high frequency induction heating and executing rapid cooling after that. SOLUTION: An austenitic stainless steel strip 1 cut to a prescribed width is delivered and is fed to a rolling roll machine 6 via a shearing machine 4 and an edge scarf 5 from a bending straightening machine 3, where the stainless steel strip 1 is formed into a product sheet thickness. Then, the stainless steel strip 1 is continuously fed to a high frequency induction heating machine 8, is heated in the temp. range of 1,100 to 1,200 deg.C, is thereafter fed to a cooling machine 9 and is rapidly cooled, and its shape is softly modified by a modifying machine 10. Furthermore, preferably, the product sheet thickness is regulated to 2 to 12 mm, and the oscillation frequency of the coil surrounding the stainless steel strip 1 at the time of high frequency induction heating is regulated to 100 to 200 kHz.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a flat stainless steel.

[0002]

2. Description of the Related Art Generally, austenitic stainless steel flat steels are used in various fields, but are often used particularly for structures requiring corrosion resistance and for decorative landscape materials. In the case of structures, machining and bending were required, and when used for decorative landscape materials, surface polishing was required. Therefore, a stainless steel flat plate having low hardness and good workability is required.

Conventionally, stainless steel flat steel has been manufactured (produced).
In order to produce a stainless steel strip of a predetermined width by cold forming into a thin stainless steel flat steel, Therefore, there is a method of annealing this.

[0004]

However, in the above-described hot rolling or hot extrusion method, molding is difficult due to a decrease in temperature during the production process, and the surface is easily scratched during the manufacturing process. If it occurs, it needs to be corrected by polishing or the like. Moreover, the product had large variations in dimensions and the surface was rough. In addition, thin flat steel sheets are generally produced in many kinds and in small quantities, and this method requires many kinds of rolling rolls and dies according to size, and is not suitable for this kind of small-piece production.

In the above-described annealing method, the annealed product is bent or twisted, and it is necessary to correct (or correct) these. And, as the correction method, there are roll correction, stretch correction and the like. However, in the roll straightening, work hardening is likely to occur in the straightening process, and there is a possibility that a so-called nose bend in which the tip is bent may occur. Also, in stretch straightening, material loss has been increased because the amount of material gripping at both ends is cut off. In addition, these straightening methods increase the number of production steps, resulting in low yield, and poor workability, so that they are more expensive than hot-rolled products and are not suitable for mass production.

Therefore, an object of the present invention is to provide a method for producing a stainless steel flat steel sheet capable of producing a wide variety of small-quantity thin austenitic stainless steel flat sheets having good workability and dimensional accuracy. .

[0007]

In order to achieve the above-mentioned object, a method for producing a stainless steel flat steel according to the present invention comprises forming an austenitic stainless steel strip having a predetermined width to a product thickness by cold forming. Then, continuously in this production line, the stainless steel strip with a product thickness of 1100 ° C
It is quenched after heating to 1200 ° C.

Further, the austenitic stainless steel strip having a predetermined width is formed into a product thickness of 2 mm or more and 12 mm or less by cold forming, and the oscillation frequency of the coil surrounding the stainless steel strip during high frequency induction heating is set to 100 kHz to 200 kHz. It is also preferable to measure the temperature, line running speed, and wall thickness of the stainless steel strip formed into the product thickness by cold forming, and control the high-frequency induction heating condition based on each data. Is also preferred.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a manufacturing apparatus used in the method for manufacturing a stainless flat steel according to the present invention. The manufacturing apparatus includes a wound body 2 formed by winding an austenitic stainless steel strip 1 cut to a predetermined width. A bending habit correcting machine 3 for taking a bending habit of the stainless steel strip 1 sent out from the wound body 2, a shear 4, an edge scarf 5 for cutting the edge of the stainless steel strip 1, and a stainless steel strip 1. A rolling mill 6 for forming a product thickness and a shaping machine 7 for shaping the stainless steel strip 1
And a high-frequency induction heater 8 for heating the stainless steel strip 1
And a cooler 9 for cooling the heated stainless steel strip 1;
A straightening machine 10 for straightening the stainless steel strip 1 and a cutting machine 11 for cutting the stainless steel strip 1 to a predetermined size are provided, which are sequentially arranged from the upstream side to the downstream side. The product thickness refers to a thickness dimension when a stainless steel flat steel is formed as a product.

The bending habit correcting machine 3 has a habit of bending the stainless steel strip 1 by forming the winding body 2, and a plurality of bending habits disposed above and below the stainless steel strip 1. Rollers 15 are provided. By passing through the bending habit correcting machine 3, the stainless steel strip 1 becomes straight.

The shear 4 is used for cutting the joint of the stainless steel strip 1, and the edge scarf 5 is used for chamfering the corner of the end face. These are used as necessary. I do.

Next, the rolling mill 6 is provided with rolling rollers 12 for rolling the stainless steel strip 1 passing therethrough,
By this rolling, the stainless steel strip 1 has a product thickness (for example, 2 mm to 12 mm). Then, the shaping machine 7 shapes the rolled stainless steel strip 1. That is, the shaping machine 7
As shown in FIG. 4, upper and lower rollers 16, 17 and left and right rollers 18,
A pair of rollers 20 and 20 comprising a pair of rollers 19 are formed.

Accordingly, the steps from the wound body 2 to the shaping machine 7 are cold forming steps, and the stainless steel strip 1 having a predetermined width is formed to a predetermined product thickness by cold forming.

Thus, as shown in FIGS. 1 and 3, the high-frequency induction heater 8 is provided with a coil through which the stainless steel strip 1 passes.
The coil 21 is provided with an electric current to heat the stainless steel strip 1. In this case, it is preferable that the high-frequency induction heater 8 has an oscillation output of 600 KW and an oscillation frequency of 100 KHz to 200 KHz. That is, if the oscillation frequency is less than 100 KHz, a rapid temperature rise of the stainless steel strip 1 cannot be expected, and conversely, 200 KHz
Is exceeded, only the surface layer is heated, resulting in uneven heating inside.

The high-frequency induction heater 8 rapidly heats the stainless steel strip 1 to 1100 ° C. to 1200 ° C. By the way, if this heating is less than 1100 ° C., carbides may be precipitated, and if it exceeds 1200 ° C., on the other hand, dimensional accuracy may be difficult due to excessive softening, and austenitic stainless steel It is preferable that the band is rapidly heated to 1100 ° C to 1200 ° C. Here, rapid means, for example, 0.5 to
One second.

The high-frequency induction heater 8 is used at 1100 ° C.
The stainless steel strip 1 rapidly heated to ~ 1200 ° C is rapidly cooled by a cooler 9.
It has a large number of nozzles 22.
To cool the stainless steel strip 1 by injecting it into the stainless steel strip 1. Each nozzle 22 is connected to a cooling water supply source (not shown), and cooling water is supplied to each nozzle 22 from this cooling water supply source. Here, the rapid cooling is, for example, cooling to 50 ° C. to 80 ° C. in 5 seconds.

Further, the straightening machine 10 has a number of rollers 23... And straightens and straightens the stainless steel strip 1 coming out of the cooler 9. Then, the stainless steel strip 1 coming out of the straightening machine 10 is cut into predetermined dimensions by a cutting machine 11 to form a stainless flat steel as a product.

By the way, as shown in FIG. 2, the apparatus is provided with control means 25 for controlling the high-frequency induction heating condition of the high-frequency induction heater 8. That is, this device is a speed detector that measures the line traveling speed of the stainless steel strip 1.
26 and a thickness detector 27 for measuring the thickness of the stainless steel strip 1
And a temperature detector 28 for measuring the temperature of the stainless steel strip 1 heated by the high-frequency induction heater 8. Data from these detectors 26, 27, 28 is input to the control means 25. The heat input (output) and the like are changed based on these data, and the stainless steel strip 1 is set to be rapidly heated to 1100 ° C to 1200 ° C.

Next, a method for manufacturing a stainless steel flat steel according to the present invention using the apparatus configured as described above will be described.
First, the stainless steel strip 1 is sent out from a wound body 2 formed by winding an austenitic stainless steel strip 1 cut to a predetermined width (for example, 21 mm to 105 mm) and passed through a bending habit correcting machine 3. Then, the curl is removed, and the curl is supplied from the curl corrector 3 to the rolling mill 6 via the shear 4 and the edge scarf 5. Here, the stainless steel strip 1 is formed to a product thickness (for example, 2 mm to 12 mm). In this case, the width of the stainless steel strip 1 is, for example, 20 mm to 100 m.
m. Thereafter, the upper and lower surfaces and both side surfaces of the stainless steel strip 1 are shaped by passing through the shaping machine 7.

Then, the stainless steel strip 1 is continuously sent to a high-frequency induction heater 8 to rapidly heat it to 1100 ° C. to 1200 ° C. After this heating, it is sent to a cooler 9 for rapid cooling (for example, 50 ° C.).
(Cooling to ℃) and straightening the shape lightly with the straightening machine 10.
Next, the straightened stainless steel strip 1 is cut to a predetermined size (for example, 4000 mm) by a cutting machine 11, thereby forming a stainless steel flat plate having a thickness of 2 mm to 12 mm and a width of 20 mm to 100 mm. I do. That is, according to this production line, after the stainless steel strip 1 is cold-formed, annealing is continuously performed in this production line.

In this case, the traveling speed of the stainless steel strip 1 is detected by the speed detector 26, the thickness of the stainless steel strip 1 is detected by the thickness detector 27, and the temperature detector 28 is detected by the temperature detector 28. Based on these data, the temperature of the heated stainless steel strip 1 is detected, and a current corresponding to the running speed, the thickness, and the like is passed through the coil 21 of the high-frequency induction heater 8 so that the stainless steel strip 1 is heated. 1100 ° C ~ 12
It is set so that it can be rapidly cooled to 00 ° C. and then rapidly cooled.

As described above, the high-frequency induction heater 8 has an oscillation output of 600 KW and an oscillation frequency of 100 KHz.
By using a steel plate with a thickness of up to 200 KHz, it is possible to heat austenitic stainless steel with a plate thickness of 2 mm to 12 mm and a width of 20 mm to 100 mm, and at the same time the running speed (forming speed).
Up to 20m / min. At this time, the clearance (gap) between the stainless steel strip 1 and the coil 21 is, for example, 10 mm.
By setting to about 20 mm, heating can be performed more efficiently.

Thus, the coil of the high-frequency induction heater 8
The stainless steel strip 1 passing through 21 has a plate thickness of 2 mm to 12 mm and a width of 20 mm to 100 mm, so that the coil 21 may be relatively small, thereby concentrating energy. it can. In addition, the coil 21 can be replaced with the optimum coil 21 according to the size of the stainless steel strip 1 passing therethrough, and high-efficiency heating can be performed.

[0025]

Since the present invention is configured as described above, the following effects can be obtained.

According to the method for producing a stainless steel flat steel according to the first aspect, the stainless steel strip 1 can be rapidly heated, and the operation and stoppage of the entire production line can be quickly dealt with, and the yield can be reduced. As a result, high-mix low-volume production is possible. In addition, highly efficient heating can be performed with the optimum coil 21 according to the work size (the size of the stainless flat steel to be produced).

According to the method for producing a stainless steel flat steel according to the first aspect, a product having good dimensional accuracy (compared to a hot product) and good surface finish (finished skin) can be produced at low cost and reliably. It can be manufactured, and can be utilized for multi-product small-quantity production without the need for many types of rolling rolls and dies for each size.

According to the method for manufacturing a stainless steel flat steel according to the first aspect, the high-frequency induction heater 8 capable of achieving downsizing and space saving is efficiently heated to produce (manufacture) high quality products. Can be realized.

According to the method for manufacturing a stainless steel flat steel according to the second aspect, an austenitic stainless steel flat steel having more excellent workability and dimensional accuracy can be reliably manufactured.

According to the method for producing a stainless steel flat steel according to the third aspect, it is possible to stably provide high quality (austenitic stainless steel flat steel excellent in workability and dimensional accuracy).

[Brief description of the drawings]

FIG. 1 is an overall simplified view of a manufacturing apparatus used in a method for manufacturing a stainless steel flat steel according to the present invention.

FIG. 2 is a block diagram.

FIG. 3 is a simplified view of a main part of a high-frequency induction heater.

FIG. 4 is a simplified diagram of a main part of the shaping machine.

[Explanation of symbols]

 1 austenitic stainless steel strip 21 coils

Claims (3)

[Claims] 1. An austenitic stainless steel strip 1 having a predetermined width is formed into a product thickness by cold forming, and then continuously in this production line, a high-frequency induction heating is performed to obtain a stainless steel strip 1 having a product thickness. A stainless steel flat bar manufacturing method characterized in that the steel plate is heated to 1100 ° C to 1200 ° C and then rapidly cooled. 2. The austenitic stainless steel strip 1 having a predetermined width is formed into a product thickness of 2 mm or more and 12 mm or less by cold forming, and the oscillation frequency of the coil 21 surrounding the stainless steel strip 1 during high-frequency induction heating is adjusted. 2. The method for producing a flat stainless steel according to claim 1, wherein the frequency is 100 kHz to 200 kHz. 3. The high-frequency induction heating condition is controlled based on each data by measuring a temperature, a line running speed, and a wall thickness of the stainless steel strip 1 formed into a product thickness by cold forming. 2. The method for producing a stainless steel flat bar according to item 1.