JPH0220610A - Manufacture of cold rolled stainless steel strip having good property for buffing - Google Patents

Abstract

PURPOSE:To manufacture a cold rolled stainless steel strip having good properties for buffing with high yield by immediately deciding the properties for buffing by surface inspection after pickling and immediately grinding the strip as necessary for manufacturing the strip by hot rolling, annealing, pickling, cold rolling, annealing, and pickling. CONSTITUTION:After a hot rolled stainless steel strip 1 is passed through an annealing furnace 2, cooler 3, pickling bath 4, washing bath 5, and dryer 6, the surface of the strip 1 is inspected by a metal surface inspection instrument 10. If it is decided to be necessary to perform grinding treatment, a signal is sent to a controller 12 and the strip 1 is passed between a grinding roll 11a and a backup roll 11b and both the surface of the strip 1 are ground by the roll 11a. A grinding roll consisting of hard bristles containing abrasive grains such as SiC of #80-#240 is used as the roll 11a. The properties for buffing of a cold rolled and annealed stainless steel strip 1 is improved and the strip 1 whose total surfaces being uniform and beautiful base surfaces by succeeding buffing is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a cold rolled stainless steel strip with excellent buffing properties.

[Conventional technology]

Cold rolled stainless steel strip specified in JIS G 4307 and JIS G 430 obtained by shearing this
The cold-rolled stainless steel sheets specified in Section 5 not only have excellent properties such as corrosion resistance, but also the copper strips and steel sheets themselves, as well as when they are formed into various products. Their surface is characterized by their clean and beautiful surface, and they are often used for such purposes.Therefore, the copper strips, steel plates themselves, and various processed products of these are often buffed or polished. It is required to have excellent buffing properties, that is, to easily become beautiful when exposed to water. Specifically, the buffing properties that these copper strips and steel plates should have include, for example, #400 paper specified in JIS R6001 as the minimum standard condition.
It is required that a beautiful stainless steel surface with a uniform surface can be obtained by polishing it 50 times using abrasive paper.

Now, cold-rolled stainless steel strips that should have such properties are generally made from hot-rolled stainless steel strips obtained by hot-rolling stainless steel slabs, and have this hot-rolled structure and are processed easily. A material produced by first annealing a hardened raw steel strip to improve its structure and soften it to increase workability and facilitate subsequent cold rolling, and then hot rolling and annealing. At least once after the treatment is carried out in a series of continuous annealing and pickling equipment that is connected to the same equipment that performs surface scale removal, immobilization treatment, and pickling treatment to make the surface beautiful. It is manufactured by performing the above-mentioned cold rolling, annealing and pickling treatment, and further performing temper rolling (skin pass rolling) or the like as necessary.

More specifically, the manufacturing method that has been adopted for manufacturing cold rolled stainless steel strips that require this buffing property will be explained with reference to the drawings. FIG. 3 is a process diagram, with some parts omitted, for explaining an example of a conventional method for manufacturing a cold rolled stainless steel strip.

One of the conventional methods is to heat a hot rolled stainless steel strip 1 as a raw material obtained by hot rolling, for example, in an annealing furnace 2. Cooling device 3. Pickling tank4. After being treated in the first annealing and pickling process consisting of continuous annealing and pickling equipment consisting of a cleaning device 5 and a dryer 6, etc., the treated surface is inspected by visual inspection etc. when it is wound up to form a coil 7. , when it is determined that treatment to improve buffing performance is necessary, the next belt grinding equipment 8
The surface is ground in a belt grinding process consisting of (this belt grinding process is not performed when it is judged that buffing property improvement treatment is unnecessary) and is wound up to form a coil 9. In this method, a cold rolled stainless steel strip is obtained through a finish rolling process consisting of a finish rolling process and a finish annealing pickling process consisting of a continuous annealing and pickling facility (not shown) similar to the above. However, in the case of this conventional method, in addition to the cold rolling equipment and the continuous annealing and pickling equipment, belt grinding equipment 8
Moreover, this belt grinding equipment 8 is usually configured with a large number of grinding belts installed in tandem and requires a large amount of equipment investment, and it generates a large amount of grinding oil containing a large amount of dust, oil smoke, and grinding sludge. The installation space is quite large and a separate line is installed to prevent adverse effects on other equipment, since this can cause a worsening of the work environment. As a result, the continuity is broken and the work has to be carried out on two lines, creating logistical obstacles such as the need for a large amount of in-process coils and storage space, as well as a large loss of time and labor. There were problems such as a decrease in productivity and a decrease in yield. Further, in this belt grinding process, the life of the grinding belt is short, so it must be replaced frequently, which not only has poor workability but also requires a large amount of grinding cost.

Another conventional method (not shown) is to treat the raw steel strip with a first annealing and pickling process as described above, followed by a cold rolling process and a subsequent annealing and pickling process (in the present invention, this continuous process is performed). These two processes are collectively called the rolling/annealing/pickling process)
This method repeats twice. In this case, the former is an intermediate process, and the latter is a finishing process, and the processes that make up each are an intermediate cold rolling process, an intermediate annealing pickling process, a final cold rolling process, It is called the final annealing pickling process. However, in the case of the conventional method that involves two stages of rolling, annealing, and pickling, the surface of the raw steel strip appears to be gradually beautified by performing the cold rolling process and the annealing and pickling process twice, and the buffing process is improved. Sexuality also improves, but not beyond what is absolutely required.

The buffing property of the surface of this raw steel strip refers to the degree of occurrence of various defects on the surface and surface layer of the stainless steel slab.

This is due to the condition of the surface and surface layer of the hot rolled stainless steel strip, which varies depending on various hot rolling conditions, as well as the surface care method and degree of care of the slab.
The quality of the buffing properties of the raw steel strip during the subsequent manufacturing process is determined. This buffing property is gradually improved by repeatedly cold rolling and elongating the raw steel strip, annealing and pickling, and descaling the surface, but it is still insufficient. This resulted in raw steel strips that had poor buffing properties and had no commercial value or could not be manufactured as they were.

Yet another conventional method is to visually evaluate the buffing properties at the end of the intermediate annealing and pickling process in order to improve the drawbacks of the two-stage rolling, annealing and pickling process. death,
In this method, the defective material steel strip is ground in a belt grinding process on a separate line, similar to the conventional method described at the beginning, and then subjected to a final cold rolling process and a final annealing pickling process. However, even with this improvement method, problems and drawbacks similar to those caused by the belt grinding process described above have occurred.

[Problem to be solved by the invention]

The object of the present invention is to solve the problems and drawbacks of the prior art,
Even when grinding steel strips with poor buffing properties during the manufacturing process, smooth logistics saves time.

The object of the present invention is to configure a method for manufacturing cold-rolled stainless steel copper strips that has excellent buffing properties so that it can be carried out more economically without causing labor loss, improving productivity, and reducing yield. .

[Means to solve the problem]

As a result of various studies in order to solve the above problems, the present inventors automatically inspected the surface flaws, bare surface, etc. of the raw steel strip that has been processed in the annealing and pickling process and is running, and based on the inspection results. Immediately determining whether the buffing properties are good or bad, and if grinding is necessary, immediately grinding is carried out on the same line as this annealing and pickling process, and this makes existing metal surface inspection equipment ingenious. The present invention was accomplished by discovering that the above-mentioned problems can be solved by using a roll grinding device equipped with a specific grinding roll as a grinding device.

EMBODIMENT OF THE INVENTION Hereinafter, the method for manufacturing a cold rolled stainless steel strip with excellent buffing properties according to the present invention will be explained in detail with reference to the drawings.

Fig. 1 is a partially omitted process diagram for explaining an example of the method for manufacturing a cold rolled stainless steel strip with excellent buffing properties according to the present invention, and Fig. 2 is a grinding roll of a roll grinding device. FIG. 3 is a diagram showing the relationship between the average particle size of abrasive grains used in and the buffing rank.

The method of the present invention uses a hot-rolled stainless steel strip obtained by hot rolling as a raw material, and first processes this raw material steel strip in an annealing and pickling process, followed by a cold rolling process and an annealing and pickling process in sequence. There is no difference from the conventional method in that a cold-rolled stainless steel strip is manufactured through a manufacturing process that includes at least one rolling, annealing, and pickling process. The feature of the method of the present invention is that the first
As shown in the figure, a metal surface inspection device 10 for detecting surface flaws, roughness, etc. of a raw steel strip 1, and a roll grinding device 1 equipped with one or more specific grinding rolls lla, which will be described later.
1 is installed immediately after the first annealing pickling process (this annealing pickling process is the same as the conventional one) and/or immediately after the annealing pickling process in the intermediate process,
A control device 1 receives a signal from a metal surface inspection device 10, immediately determines the necessity of grinding to improve the buffing properties of the raw steel strip 1, and issues a command signal to a roll grinding device 11 to operate it.
2, the raw steel strip 1 running through the annealing and pickling process is constantly monitored by the metal surface inspection device 1O, and when grinding is necessary, the roll grinding device 11 is immediately removed while continuing to run.
The purpose is to perform the grinding process.

The surface of the raw steel strip 1 is changed by annealing and pickling, and the treated surface at this point is the cleanest and the surface condition can be accurately inspected, so the metal surface inspection device 10 is installed in the same line immediately after the annealing and pickling process. It is better to set it up. and,
This raw material steel strip 1 is running while being tracked during the annealing and pickling process, and based on the inspection results by the metal surface inspection device 11G, the portion length (
Since it is most efficient to grind accurately and immediately while continuing to run the metal surface inspection device 10, a roll grinding device 11 is installed in the same line behind the metal surface inspection device 10.
It is preferable to install

As mentioned above, the quality of the buffing property is determined by the surface of the hot-rolled stainless steel strip 1 and the roughness of the surface layer, so the annealing process that first processes the hot-rolled stainless steel strip 1, which is the raw material steel strip, It is preferable to first install the metal surface inspection device 10 and the roll grinding device 11 in the same line immediately after the pickling process.

In addition, if the rolling/annealing/pickling process is repeated as an intermediate process and a finishing process, the metal surface inspection device IO and roll grinding machine M11 should be used immediately after the first annealing/pickling process and/or during the annealing/pickling process in the intermediate process. It is only necessary to select and install them in the same line immediately after the process in a way that maintains the desired productivity and completely guarantees buffing performance in the most economical manner.

In either case, when a partial length or the entire length of a raw steel strip with poor buffing properties is ground by the roll polishing device 11, grinding marks remain that deteriorate the buffing properties of the ground surface, but as a subsequent manufacturing process, at least By going through one finishing process or an intermediate process and a finishing process, these grinding marks can be eliminated, and a cold rolled stainless steel strip with excellent buffing properties and a -like finish over the entire length can be manufactured as a product. It is.

The metal surface inspection device 10 scans, for example, in a direction (width direction) perpendicular to the running direction of the raw steel strip 1, and transmits a signal according to the surface condition of the raw steel strip 1 as it travels. The control device 12 is a metal surface inspection device! ! The signal received from 10 is image-processed, that is, based on pulses synchronized with the running of the raw steel strip 1, the target surface is divided into meshes of unit area to create patterns such as flaws and texture, and the width of each pattern is
The necessity of grinding to improve buffing performance is determined based on the length, area, number, etc., according to pre-stored standards, and if necessary, a command signal is sent to the roll grinding device 11. As such a metal surface inspection device 10 and a control device 12, for example, the detection head and control section of an existing metal surface inspection device that uses a laser light source can be processed and used as necessary. - A detection head TO5PECTOR700 manufactured by Toshiba is shown.

An example of a method for determining the criteria for determining the necessity of grinding treatment for improving buffing properties in the present invention will be described.

First, buff properties are classified into the following eight ranks.

A: Grinding 50 times using paper with an average abrasive grain size of 81,000, resulting in a uniform and beautiful surface with a stainless steel texture (hereinafter referred to as #1000, 150 times grinding) B Uni: 8800, 150 times grinding B: 1600,150 times Grinding B, : 8400150 times grinding C, : #320150 times grinding C2: 1280150 times grinding C3: 8240150 times grinding D: The surface is not uniform after 50 times grinding with #240 paper Applicable to any of the above rankings. Whether or not grinding is required for a cold-rolled stainless steel strip product depends on the degree of beauty required for the cold-rolled stainless steel strip product, that is, the degree of buffing required. Grade 1.

Ranks 81 to B3 are 2nd grade, and ranks C1 to C3 are 3rd grade.

Rank D is the scrap grade, and this third grade and the scrap grade are the ranks that require grinding processing. Then, by experimenting in advance, for each rank, the width, length, 2 area, etc. of patterns such as flaws and background of the material steel strip 1,
The number is memorized, and when a steel strip 1 made of any material is actually passed through and the surface properties such as scratches and bare surface are inspected, it is determined whether it is grade 1, grade 2, grade 3, or scrap grade. A control device W11 is configured to send a command signal to the roll grinding device 11 in the case of grade and scrap grade.
2 is set.

Roll grinding device used in the method of the present invention! The grinding roll lla, which is provided at least one in 11, is made of rigid bristles made of nylon or the like containing abrasive grains of a specific average particle size, which are flocked into a disk shape, laminated and compressed, and then rolled. Any material that is roll-shaped and has grinding ability, such as one molded into a shape, may be used, but the average particle size must be between #80 and #240. The abrasive grains may be those having wear resistance and grinding ability, such as SiC, Arachi, or 03.

The reason why the average grain size of the abrasive grains is limited to #80 or more and #240 or less will be explained below. Figure 2 shows stainless steel grade 5US3.
04 hot-rolled stainless steel strip is used as a raw material, this raw steel strip is subjected to an initial annealing and pickling treatment, and then immediately after passing through the intermediate rolling/annealing and pickling process, the average particle size of the abrasive grains is changed. Using a grinding roll lla, a steel strip 1 with a thickness of 1.5 m was subjected to a grinding treatment using water, and then subjected to a finish rolling process and a final annealing grinding process at a rolling rate of 60%, and the buffing properties were examined. , plotted according to the buffing rank. In Figure 2, rank B has good buffing properties.

(Grade 2) or higher means that the average grain size of the abrasive grain is #80 or more #2
40 or less is used, and #150
The A (1st class) rank and buff rank have improved the most. If the average grain size is less than 480 and the average grain size becomes large, grinding marks will remain on the surface of the raw steel strip 1 even after the finishing process, worsening the buffing properties of the cold rolled stainless steel strip product.
In addition, if the average particle size exceeds #240 and the average particle size becomes small, the grinding ability of the roll grinding device 11 will be poor, making grinding processing difficult on the same line, and the buffing properties of the product will not improve. .

For the above reasons, the average particle size of the abrasive grains contained in the bristles of the grinding roll lla was determined.

Even one grinding roll lla like this can improve buffing performance, but by installing multiple rolls, some of them can be used as spares to quickly respond to the need to replace the grinding roll lla currently in use or in the event of an abnormality. The average grain size of the abrasive grains is #80 in order to make it easier to remove grinding marks.
Arranging grinding rolls with different average grain sizes from #240 (larger grain size) to #240 (smaller grain size), or automatically increasing or decreasing the number of grinding rolls to be used based on the results of inspecting the condition of the surface texture. , it is possible to use it flexibly.

During grinding, the grinding roll lla is positioned with the raw steel strip 1 sandwiched between it and the backup roll flb, as shown in FIG. The upper and lower grinding rolls lla and backup rolls are moved backwards in a direction perpendicular to the running direction of the raw steel strip 1 so as not to contact the surface of the steel strip 1, and this position movement is controlled by a command signal from the control device 12. It is preferable that the process be performed independently for each coarse line consisting of llb.

〔Example〕

Next, the method of the present invention will be described in more detail in a table based on examples of the method of the present invention and comparative examples of conventional methods.

These Examples and Comparative Examples are made of a steel type 5US304 with strong requirements for buffing properties, plate thickness 4.0 [■] x plate width 1030 [■].
A hot-rolled stainless steel strip manufactured in Japan was used as material steel strip 1 and was manufactured according to the manufacturing process shown in the table.

The table shows the material and average particle size of the abrasive grains of the grinding roll lla, the dimensions of the raw steel strip 1 in the intermediate annealing and pickling process, the rolling ratio (%) in the final cold rolling process, and the cold rolled stainless steel strip product. It shows the buff rank.

In this table, the symbols written in the manufacturing process are as follows.

First, in the method of the present invention, as shown in FIG. 1, a continuous annealing sink or annealing furnace 2. Cooling device 3. Pickling tank 4゜Cleaning device 5. Immediately after the equipment equipped with the dryer 6 (abbreviated as AP), a metal surface inspection device l! 10 and a roll grinding device W111 having a grinding roll lla are connected by a control device 12. A continuous annealing and pickling grinding equipment is used.

This process is displayed in APG. The process when this continuous annealing, pickling and grinding equipment is used when first annealing and pickling the raw steel strip 1 is indicated by A P G (H), and the process in the case of an intermediate process is indicated by A P G ( I).

Furthermore, the steps of the conventional method are expressed as follows.

A P (H): First annealing and pickling process ZM (I): Intermediate cold rolling process A P (I): Intermediate annealing and pickling process CG: Belt grinding process ZM (F): Finish rolling process A P (F) ): Margin below the final annealing pickling process As can be seen from this table, as a comparative example, the conventional method ■, ■
In the case of the manufacturing process, no measures were taken to improve the buffing performance, so the buffing performance ranks were all in the defective range of C1 to D level, and did not exceed the minimum condition of B and level.

In the case of the same manufacturing process (■, ■, ■) of the conventional method, the process (CG) using the belt grinding equipment 8 is changed to A in order to improve the buffing property during the manufacturing process, although it is a separate process (separate line).
Since it is adopted after the P (H) process or after the A P (I) process, it is possible to achieve a buffing rank of B3 or higher, but in order to perform belt grinding using grinding oil on a separate line. It became clear that there were major problems, such as deteriorating the working environment, creating logistics obstacles, lowering productivity and yield, and requiring large amounts of grinding costs.

On the other hand, in the embodiments according to the method of the present invention, in order to improve the buffing properties of the raw material steel strip 1, the grinding was performed by flocking bristles containing abrasive grains with an average grain size of #80 or more and #240 or less. A P G (H) process and/or p, p a equipped with a roll grinding device 11 having rolls lla
(I) Because the process is adopted and manufactured.

It is possible to guarantee the buffing performance of all cold rolled stainless steel strip products manufactured at B level or above, and if the average particle size of the abrasive grains is appropriate, and the arrangement and number of grinding rolls used are carried out, the buffing performance will be improved. It is possible to improve the rank to A level, and in addition, each device for improving buffing properties can be included in the continuous annealing and pickling process, making it possible to shorten the process and facilitate production with smooth logistics. I was able to improve my sexuality.

〔Effect of the invention〕

The method of the present invention has been recognized to have the following effects as a method for producing cold rolled stainless steel strips with excellent buffing properties, and its industrial value is extremely large.

1. Continuously and automatically inspects the surface of the raw steel strip and the condition of the surface layer, and based on the inspection results, automatically grinds the part length at the position to be ground accurately and immediately as necessary. By configuring the process to be carried out continuously in the same line as the annealing and pickling line, the manufacturing process is shortened compared to conventional methods, and the number of coils in progress and their storage space can be saved through smooth logistics. This makes it possible to perform the grinding process necessary to improve buffing properties at the same time as the annealing and pickling process, improving productivity and making it possible to stably guarantee buffing properties.

2. Unlike the process using belt grinding equipment in the conventional method, there is no need to grind the wrong part length at the position to be ground or grind more than necessary as a precaution, and the yield is improved.

3. The method of the present invention uses a roll grinding device that uses water instead of the belt grinding equipment that uses grinding oil in the conventional method.
Frequent replacement of belts is completely eliminated, resulting in labor savings, and there is no post-processing of grinding oil, resulting in a very favorable working environment, which allows grinding to be performed on the same line as the annealing and pickling process, and reduces overall grinding costs. Now you can.

[Brief explanation of the drawing]

Fig. 1 is a partially omitted process diagram for explaining an example of the method for manufacturing a cold rolled stainless steel strip with excellent buffing properties according to the present invention, and Fig. 2 is a grinding roll of a roll grinding device. Figure 3 is a diagram showing the relationship between the average grain size of abrasive grains used in and buffing rank, and Figure 3 is a process diagram with some parts omitted to explain an example of a conventional method for manufacturing stainless steel strips. It is. In the drawing 1... Hot rolled stainless steel strip (material steel strip) 2...
... Annealing furnace 3 ... Cooling device 4 ... Pickling tank 5 ... Cleaning device 6 ... Dryer 7 ... Coil 8 ... Belt grinding equipment 9 ... - Coil 10...Metal surface inspection device 11...Roll grinding device 11a...Grinding roll 11b...Backup roll 12...Control device 2 Co-grinding roll average grain size , ,hmm

Claims (1)

[Claims] 1. Using a hot-rolled stainless steel strip obtained by hot rolling as a material, this material is treated in an initial annealing and pickling step, and then further subjected to cold rolling and annealing and pickling steps. In manufacturing cold-rolled stainless steel strip through a manufacturing process that includes rolling, annealing, and pickling at least once, metal surface inspection equipment is used to detect flaws, texture, etc. on the surface of the raw steel strip, and then an average A roll grinding device equipped with one or more grinding rolls flocked with bristles containing abrasive grains having a particle size of #80 to #240 is installed immediately after the first annealing and pickling process, and the metal surface inspection is performed. We installed a control device that receives signals from the device, instantly determines the need for grinding to improve the buffing properties of cold-rolled stainless steel strips, and sends a command signal to the roll grinding device to operate it. A buffing method characterized in that the raw steel strip running through the annealing and pickling process is constantly monitored by the metal surface inspection device, and if grinding is necessary while continuing the running, it is immediately ground by the roll grinding device. A method for producing cold-rolled stainless steel strip with excellent properties. 2. The buffing property according to claim 1, wherein the rolling/annealing/pickling process is repeated twice as an intermediate process and a finishing process, and the metal surface inspection device and the roll grinding device are installed immediately after the annealing/pickling process in the intermediate process. How to make superior cold rolled stainless steel strip. 3 After the first annealing and pickling process, the rolling/annealing and pickling process is repeated twice as an intermediate process and a finishing process, and the metal surface inspection device and roll grinding device are used immediately after the first annealing and pickling process and again in the intermediate process. 2. The method for producing a cold rolled stainless steel strip with excellent buffing properties according to claim 1, wherein the method is carried out immediately after the annealing and pickling step.