JP4862690B2 - Stainless steel strip and method for producing stainless steel strip - Google Patents

Description

  The present invention relates to a stainless steel strip excellent in surface properties, such as a stainless hot-rolled steel strip and a stainless cold-rolled steel strip characterized by a method for removing scale formed on the surface, and a method for producing a stainless steel strip.

Conventionally, when a heated slab is hot-rolled in a stainless steel strip manufacturing process, an oxide layer (hereinafter referred to as “scale”) is formed on the surface after hot-rolling. There are many. Therefore, in order to remove this scale and obtain excellent surface properties, the scale is often removed.
As such a scale removal method, for example, there is a method described in Patent Document 1.

  In the method described in Patent Document 1, first, a mechanical preliminary scale removal process such as a shot blast process or a roll bending process is performed on a stainless steel strip after hot rolling. And it is the method of removing the scale formed in the surface by performing the pickling process immersed in acid solutions, such as a sulfuric acid, nitric acid, and hydrofluoric acid, with respect to the stainless steel strip which performed this preliminary scale removal process .

  Since the scale formed on the surface of the stainless steel hot-rolled steel strip is denser and stiffer than the scale formed on the surface of other steel strips, such as steel strip formed using carbon steel, the acid solution It is difficult to remove the scale only by performing the pickling treatment immersed in the inside. Therefore, in order to efficiently remove the scale formed on the surface of the stainless hot-rolled steel strip, a shot blasting process is required as a preliminary scale removing process performed before the pickling process.

  When shot blasting is performed as a preliminary scale removal treatment for pickling, and cracks such as cracks and peeling occur on the scale formed on the surface of the stainless hot-rolled steel strip, cracks generated in the scale during pickling It becomes easy to let acid penetrate. For this reason, it becomes easy to peel a scale from the interface of a base metal and a scale, and it becomes possible to remove efficiently the scale formed in the surface of a stainless steel hot-rolled steel strip.

In the scale removal method as described above, in order to efficiently remove the scale formed on the surface of the stainless hot-rolled steel strip, since the importance of the pickling treatment is high, a large amount of acid is used in the pickling treatment. There are many cases to do.
However, in recent years, acid emission regulations have become stricter, and in order to satisfy the emission regulations, the cost associated with the emission process increases. In addition, as a large amount of acid is used in the pickling treatment, costs associated with waste acid treatment such as treatment for neutralizing the waste liquid after the pickling treatment and disposal of the neutralized product increase. Therefore, there is a possibility that the problem that the manufacturing cost of the stainless steel strip increases will occur.

In order to solve such a problem, for example, a stainless steel strip manufacturing method described in Patent Document 2 is used.
The manufacturing method of the stainless steel strip described in Patent Document 2 performs shot blasting on the stainless steel strip after hot rolling, and corrects the shape of the stainless steel strip that has been shot blasted.
And the heavy grinding process and surface conditioning process of a stainless steel strip are performed with respect to the stainless steel strip which corrected the shape with an elastic grindstone roll. Here, with regard to the heavy grinding process and the surface conditioning process, it is possible to remove the scale by setting the total grinding amount in both processes to 50 μm or more.

With such a stainless steel strip manufacturing method, it is possible to remove the scale formed on the surface of the stainless hot rolled steel strip without performing pickling treatment. It becomes possible to decrease.
Japanese Patent Laid-Open No. 61-117291 JP-A-5-245502

However, in the method for producing a stainless steel strip described in Patent Document 2, in order to remove the scale formed on the surface of the stainless hot-rolled steel strip, the total amount of grinding in the heavy grinding process and the surface conditioning process by the elastic grinding wheel roll Is 50 μm or more.
In order to obtain such a large amount of grinding, if heavy grinding treatment and surface conditioning treatment with an elastic grindstone roll are performed, significant wear occurs on the elastic grindstone roll, so the exchange frequency of the elastic grindstone roll increases. .

Therefore, there may be a problem that productivity and yield of the stainless steel strip are lowered. In addition, the basic unit of the elastic grindstone roll related to the production of the stainless steel strip is increased, which may cause a problem that the production cost of the stainless steel strip is increased.
The present invention has been made paying attention to the problems as described above, and removes the scale formed on the surface of the stainless steel strip without performing pickling and by grinding with a small grinding amount. It is an object of the present invention to provide a stainless steel strip and a method for producing the stainless steel strip that can be used.

In order to solve the above-mentioned problem, the invention described in claim 1 of the present invention is the stainless steel strip in which the shot particles collide with the surface of the hot-rolled stainless steel strip and then the shot particles collide with the surface. A stainless steel strip manufactured by grinding the surface of
The average particle size of the shot particles is in the range of 0.15 mm to 0.25 mm,
Projection density of the shot ^particles, Ri range der of ^{80kg / m 2 ~200kg / m 2} ,
The shot particle projection speed is in the range of 60 m / sec to 100 m / sec,
Projection distance of the shot particles is characterized in der Rukoto range of 300Mm～1000mm.

According to the present invention, the average particle size of the shot particles colliding with the surface of the hot-rolled stainless steel strip is in the range of 0.15 mm to 0.25 mm, and the shot particle projection density is 80 kg / m 2 to 200 kg. / m @ 2 Ri range der of blasting speed of the shot particles is in the range of 60m / sec~100m / sec, projection distance of the shot particles, Ru der range of 300Mm～1000mm.
For this reason, the surface roughness of the stainless steel strip that has collided with the shot particles can remove the scale formed on the surface of the stainless steel strip without performing a pickling process and by a grinding process with a small amount of grinding. Possible surface roughness.
The “shot particle projection density” is the weight of shot particles projected per unit area when the shot particles collide with the surface of the stainless steel strip.

Next, the invention described in claim 2 is the invention described in claim 1, wherein after grinding the surface of the stainless steel strip on which the shot particles collide, the ground stainless steel strip is acidified. It is manufactured by cold rolling without washing.
According to the present invention, after grinding the surface of the stainless steel strip collided with the shot particles, the ground stainless steel strip is cold-rolled without pickling.
For this reason, a stainless steel cold-rolled steel strip is manufactured using a stainless steel strip from which scale has been removed by performing a grinding process with a small amount of grinding without performing a pickling process. Costs can be reduced.

Next, in the invention described in claim 3 , after the shot particles collide with the surface of the hot-rolled stainless steel strip, the surface of the stainless steel strip with which the shot particles collide is ground. A manufacturing method comprising:
The average particle size of the shot particles is in the range of 0.15 mm to 0.25 mm,
A projection density of the shot ^particles, and in the range of ^{80kg / m 2 ~200kg / m 2} ,
The shot particle projection speed is in the range of 60 m / sec to 100 m / sec,
The shot particle projection distance is in a range of 300 mm to 1000 mm .

According to the present invention, the average particle size of the shot particles colliding with the surface of the hot-rolled stainless steel strip is in the range of 0.15 mm to 0.25 mm, and the shot particle projection density is 80 kg / m 2 to 200 kg / set in the range of m2, the blasting speed of the shot particles, and in the range of 60m / sec~100m / sec, the projection distance of the shot particles, and in the range of 300Mm～1000mm, stainless steel strip is produced.
For this reason, the surface roughness of the stainless steel strip that has collided with the shot particles is such that the scale formed on the surface can be removed by a grinding process with a small amount of grinding without performing a pickling process. It becomes possible to manufacture a stainless steel strip using the stainless steel strip.

Next, the invention described in claim 4 is the invention described in claim 3 , wherein after grinding the surface of the stainless steel strip collided with the shot particles, the ground stainless steel strip is acidified. It is characterized by cold rolling without washing.
According to the present invention, after grinding the surface of the stainless steel strip collided with the shot particles, the ground stainless steel strip is cold-rolled without pickling.
For this reason, a stainless steel cold-rolled steel strip is manufactured using a stainless steel strip from which scale has been removed by performing a grinding process with a small amount of grinding without performing a pickling process. Costs can be reduced.

  According to the present invention, it is possible to remove the scale formed on the surface of the stainless steel strip without performing pickling treatment and by grinding processing with a small grinding amount. The yield can be improved and the manufacturing cost of the stainless steel strip can be reduced.

Next, embodiments of the present invention will be described with reference to the drawings.
First, the configuration of a stainless steel strip production line to which the stainless steel strip production method of the present embodiment is applied will be described with reference to FIG.
FIG. 1 is a diagram showing a configuration of a stainless steel strip production line (hereinafter referred to as “production line 1”) of the present embodiment.
As shown in FIG. 1, the production line 1 of the present embodiment is a production line that is generally used in the production of stainless steel strips, and includes a dispenser 2, a welder 4, an entry side looper 6, and a shot A blasting facility 8, a brush grinding device 10, a pickling device 12, an exit side looper 14, and a winder 16 are provided.

In addition, although the manufacturing line 1 shown in FIG. 1 has shown the manufacturing line generally used, the structure of the manufacturing line 1 is not limited to this, For example, it is continuous with an annealing line and a rolling line. It is good also as the structure which carried out. Moreover, you may use together mechanical scale removal equipment other than the shot blasting equipment 8, such as a mechanical breaker.
In such a production line 1, a strip-shaped stainless steel material (hereinafter referred to as “stainless hot-rolled steel strip 18”) that has been hot-rolled is discharged from the dispenser 2 and then preceded by the welding machine 4. The material is welded and connected, and moves to the shot blasting equipment 8 via the entry side looper 6.
The stainless hot-rolled steel strip 18 moved to the shot blasting equipment 8 collides with the surface thereof, for example, shot particles made of metal particles (hereinafter referred to as “shot blasting”), and then to the brush grinding apparatus 10. Moving.

Here, in the production line 1 of the present embodiment, various conditions of the shot blasting process in the shot blasting facility 8 are set within the following ranges.
Average particle diameter of shot particles: 0.15 mm to 0.25 mm
Shot particle projection density: 80 kg / m ^{2 to} 200 kg / m ²
Shot particle projection speed: 60 m / sec to 100 m / sec
Shot particle projection distance: 300 mm to 1000 mm
The stainless hot-rolled steel strip 18 subjected to the shot blasting process in the shot blasting equipment 8 is ground on the surface subjected to the shot blasting process by the brush grinding apparatus 10, and then the pickling apparatus 12 and the exit side looper. 14 is wound up by a winder 16 via 14.

Here, in the production line 1 of the present embodiment, in a grinding process by the brush grinding apparatus 10, a brush roll formed by mounting a rod-shaped body containing abrasive grains on a roll shaft is used, and the amount of grinding is 4 μm to 4 μm. Set within the range of 5 μm.
Moreover, in the production line 1 of this embodiment, the stainless hot-rolled steel strip 18 moved from the brush grinding apparatus 10 is passed through the pickling apparatus 12 without performing the pickling process, and is moved to the exit side looper 14. .

Hereinafter, the reason why various conditions of the shot blasting process in the shot blasting equipment are set within the above-described range will be described.
Shot blasting in a conventional production line is the penetration of acid into cracks generated in the scale during pickling by causing cracks such as cracks and delamination on the scale formed on the surface of the stainless hot-rolled steel strip. The purpose was to promote.

On the other hand, the inventors of the present invention have intensively studied various conditions of the shot blasting process through experiments and the like described later, and as a result, set the various conditions of the shot blasting process in the shot blasting equipment within the above-described range.
And it is possible to remove the scale formed on the surface of the stainless hot-rolled steel strip without performing pickling treatment by setting various conditions of the shot blast treatment within the above-described range. I found out.

Furthermore, the inventors of the present invention can remove the scale formed on the surface of the stainless steel hot-rolled steel strip even with a grinding process in which the grinding amount is small as compared with the prior art. It was found that the hot-rolled steel strip has the same degree of corrosion resistance as when pickling treatment.
Therefore, an experiment that has led to setting various conditions of the shot blasting process within the above-described range will be described below. In this experiment, a production line similar to the production line 1 of the present embodiment is used.

  In this experiment, a sample steel strip having a thickness of 4 mm, a width of 100 mm, and a length of 200 mm was cut out from a stainless hot-rolled steel strip annealed in a box-type annealing furnace after hot rolling, and shot using this sample steel strip. Various conditions of blasting were examined. As the stainless hot-rolled steel strip, a stainless hot-rolled steel strip formed from SUH409 was used, and the chemical components of SUH409 were the chemical components shown in Table 1.

In Table 1, each component is indicated by mass%.
When examining various conditions of shot blasting, the material of the shot particles, the average particle diameter of the shot particles, the shot density of the shot particles, and the shot speed of the shot particles were set to the following conditions, respectively.
As the shot particles, five types of steel shots made of the same material and having different average particle diameters were used, and shot blasting was performed on four sample steel strips for each shot particle having different average particle diameters. That is, the total number of sample steel strips is 20. The average particle diameters of the five types of shot particles were 0.08 mm, 0.15 mm, 0.25 mm, 0.4 mm, and 0.5 mm, respectively.

  Moreover, when calculating | requiring these average particle diameters, the particle size was selected using the some standard sieve based on JISZ8801, and it calculated | required by the average of the weight. As the plurality of standard sieves, standard sieves having a mesh size of 53 μm, 75 μm, 100 μm, 150 μm, 180 μm, 212 μm, 250 μm, 300 μm, 355 μm, 425 μm, 500 μm, and 710 μm were used, respectively.

Projection density of shot ^particles, the three types of ^{50kg / m 2, 100kg / m} 2, 150kg / m 2, four sample steel band used for each five kinds of shot particles, the projection density 50 kg / ^{m 2} The sample steel strip and the sample steel strip set to 100 kg / m ² were each one, and two sample steel strips having a projection density of 150 kg / m ² were used. The shot particle projection distance was 350 mm, which was the vertical distance between the projection device and the sample steel strip.

Only one type of shot particle projection speed was 65 m / sec.
Then, the sample steel strip is subjected to shot blasting under the above-described conditions using a centrifugal projection device, and the amount of scale removed from the surface of the sample steel strip by the shot blasting (hereinafter referred to as “desorption”). Described as “amount of scale”). The descaling amount was determined by measuring the weight of the sample steel strip before and after shot blasting.

  Also, according to JISB0601-2001 and JISB0651-2001, the stylus type surface roughness measuring instrument is moved to the length method in contact with the surface of the sample steel strip, and the arithmetic average roughness of the sample steel strip is measured. The measured arithmetic average roughness was recorded as the average roughness Ra. When measuring the arithmetic mean roughness, the reference length Lr (λc) for the roughness curve is 0.8 mm, the reference length Lw (λf) for the undulation curve is 8 mm, and the reference length for the cross-sectional curve The measurement was performed with the thickness Lp, that is, the evaluation length Ln being 40 mm.

Furthermore, of the four sample steel strips used for each of the five types of shot particles after shot blasting, the remaining three samples except for one of the two sample steel strips having a projection density of 150 kg / m ² The steel strip was ground using a brush roll rotated at a speed of 1000 r / min in the direction opposite to the transport direction of the sample steel strip while transporting the sample steel strip at a speed of 30 m / min. .

Here, the grinding amount of the sample steel strip by the grinding treatment was set in the range of 4 μm to 5 μm. The grinding process was performed while supplying 2 L / min of cooling water between the sample steel strip and the brush roll. Further, the brush roll used in this grinding treatment was formed by radially attaching rod-shaped bodies containing abrasive grains to the roll shaft with a diameter of 3 mm or more and having a diameter of 400 mm.
And after cold-rolling the sample steel strip after a grinding process, the scale remaining on the surface of the cold-rolled sample steel strip was measured. In addition, the cold rolling with respect to the sample steel strip after a grinding process was performed 5 passes, and the thickness was 1 mm. Further, the scale remaining on the surface of the sample steel strip was measured visually.
The results obtained from the above experiments are shown in Table 2 below.

2, among the experimental results shown in Table 2, the descaling amount, the average particle size of the shot particles (described as “shot particle size” in Table 2 and FIG. 2), and the average The relationship with roughness Ra is shown.
As shown in Table 2 and FIG. 2, the smaller the average particle size of the shot particles, the smaller the surface roughness after the shot blast treatment.
Further, as shown in Table 2 and FIG. 2, when the shot particle projection speed is the same, when the average particle size of the shot particle is 0.15 mm or 0.25 mm, the removal in shot blasting is performed. The amount of scale is increasing.

As shown in Table 2, in this experiment, the descaling amount in the shot blasting process is almost saturated at 24.8 g / m ² . For this reason, in Table 2, the case where the descaling amount is 24.8 g / m ² or more is indicated as shot descaling “O”, and the case where the descaling amount is less than 24.8 g / m ^2. , Shot descaling “×” is shown. This is the weight of the scale is the 24.8 g / m ² approximately, from the time the descaling amount became 24.8 g / m ² or more, even further subjected to shot blasting, more descaling row It is because it is not broken. In addition, when the density of the scale formed on the surface of the sample steel strip is 5500 kg / m ² , when the descaling amount is 24.8 g / m ² , it corresponds to a removal amount of 4.5 μm.

  In addition, the measurement results of the scale remaining on the surface of the cold-rolled sample steel strip (in Table 2, described in the column “Remaining scale after cold rolling”) are shown in Table 2. As shown in Experiment No. In four ways of 3-b, 3-c, 4-b, and 4-c, the scale remaining on the surface of the sample steel strip was not observed, and the scale was removed. In Table 2, in the remarks column, the experiment No. 3-b, 3-c, 4-b and 4-c are referred to as “examples of the present invention” and other experiment Nos. Is described as “Comparative Example”.

That is, when the average particle diameter of the shot particles is 0.15 mm or 0.25 mm, the shot particle has a projection density of 100 kg / m ² or 150 kg / m ² , and when the grinding process is performed In addition, the scale remaining on the surface of the sample steel strip was completely removed.
On the other hand, even when the shot descaling was “◯”, when the grinding process was not performed, the scale remaining on the surface of the sample steel strip was observed, and the scale was not completely removed. . This is thought to be because the scale is almost removed in the shot blasting process, but something like fine scale powder remains on the surface of the sample steel strip. It is presumed that it remained as a scale residue on the surface.

  On the other hand, when the average particle size of the shot particles is 0.4 mm or 0.5 mm, the shot descaling is “◯”, and even when grinding is performed, the shot particles remain on the surface of the sample steel strip. Scale was observed and the scale was not completely removed. This is presumed to be affected by the surface roughness of the sample steel strip after shot blasting. That is, when shot blasting is performed using shot particles having an average particle size of 0.4 mm or more, the surface roughness Ra of the sample steel strip after shot blasting exceeds 3 μm. Therefore, the surface roughness becomes large, and even if the grinding process is performed, a region that cannot be partially ground occurs. For this reason, it is estimated that the scale residue remained on the surface of the sample steel strip after cold rolling.

Here, with reference to FIG. 3, the relationship between the surface roughness of the sample steel strip after the shot blasting and the measurement result of the scale remaining on the surface of the cold-rolled sample steel strip will be described. FIG. 3A shows a case in which the average particle diameter of shot particles is 0.4 mm or more among the comparative examples, and FIG. 3B shows an example of the present invention.
As shown in FIG. 3 (a), the comparative example in which the average particle diameter of the shot particles is 0.4 mm or more, that is, the surface roughness Ra of the sample steel strip after the shot blasting process exceeds 3 μm. In such a case, the collision marks of shot particles formed on the surface of the sample steel strip are large. For this reason, even if it grinds, it is difficult to grind the shot particle collision trace completely, and a scale remains.

On the other hand, as shown in FIG. 3B, when the surface roughness Ra of the sample steel strip after the shot blast treatment is 3 μm or less, the surface roughness Ra is 3 μm. Compared to the case of exceeding the shot mark, the collision marks of the shot particles formed on the surface of the sample steel strip are small. For this reason, by performing the grinding process, it becomes possible to completely grind the shot marks of the shot particles, and the scale is completely removed.
For the above reasons, in the production line 1 of the present embodiment, various conditions for the shot blasting process in the shot blasting equipment 8 are set within the above-described range.

Next, operations and effects of the stainless steel strip manufacturing method in the manufacturing line 1 of the present embodiment will be described.
First, the stainless hot-rolled steel strip 18 delivered from the dispenser 2 is welded and connected to the preceding material in the welding machine 4, and moves to the shot blast facility 8 via the entry-side looper 6.
Then, in the shot-blasting equipment 8, within an average particle size of the shot particles is 0.15 mm to 0.25 mm, the range projected density of 80kg ^{/ m 2} ~200kg ^/ m 2 shots particle blasting speed of the shot particles Is set in the range of 60 m / sec to 100 m / sec and the shot particle projection distance is in the range of 300 mm to 1000 mm, respectively, and the set shot blasting process is performed on the surface of the stainless hot-rolled steel strip 18.

When shot blasting is performed on the surface of the stainless hot-rolled steel strip 18, the surface roughness Ra of the stainless hot-rolled steel strip 18 after the shot blasting is 3 μm or less. Compared with the case where the roughness Ra exceeds 3 μm, a small shot particle collision mark is formed on the surface of the stainless hot-rolled steel strip 18.
The stainless hot-rolled steel strip 18 whose surface has undergone shot blasting moves to the brush grinding apparatus 10. And the grinding process by which the grinding amount was set in the range of 4 μm to 5 μm is performed on the stainless hot-rolled steel strip 18, and the scale is completely removed together with the collision marks of the shot particles.

The stainless hot-rolled steel strip 18 that has been subjected to the grinding process by the brush grinding device 10 is taken up by the winder 16 via the pickling device 12 and the outlet looper 14.
Therefore, if it is a manufacturing method of the stainless steel strip of this embodiment, in shot blasting equipment 8, the average particle diameter of shot particles is in the range of 0.15 mm to 0.25 mm, and the shot particle projection density is 80 kg / m ^2. Within each range of ˜200 kg / m ^2, the set shot blasting process is performed on the surface of the stainless hot-rolled steel strip 18.

For this reason, the surface roughness of the stainless hot-rolled steel strip 18 collided with the shot particles is 3 μm or less, and the hot-rolled stainless steel is obtained by a grinding process with a small grinding amount of about 4 μm to 5 μm without performing a pickling process. The surface roughness is such that the scale formed on the surface of the steel strip 18 can be removed.
As a result, the productivity and yield of the stainless steel strip can be improved, and the manufacturing cost of the stainless steel strip can be reduced.

Moreover, if it is the manufacturing method of the stainless steel strip of this embodiment, in the shot blasting equipment 8, the shot particle projection speed is in the range of 60 m / sec to 100 m / sec, and the shot particle projection distance is in the range of 300 mm to 1000 mm. Inside, the set shot blasting process is performed on the surface of the stainless hot-rolled steel strip 18.
For this reason, compared with the case where the shot particle projection speed is out of the range of 60 m / sec to 100 m / sec, and the shot particle projection distance is out of the range of 300 mm to 1000 mm, the stainless hot rolled steel strip 18 The scale formed on the surface can be further removed.

  In addition, although the manufacturing method of the stainless steel strip of this embodiment was applied to manufacture of the stainless hot-rolled steel strip 18, it is not limited to this. That is, after grinding the surface of the stainless hot-rolled steel strip 18 on which the shot particles collide, the stainless hot-rolled steel strip 18 that has been ground is cold-rolled without pickling, thereby obtaining a stainless cold-rolled steel strip. You may apply to manufacture of. In this case, since the stainless cold-rolled steel strip is manufactured using the stainless hot-rolled steel strip 18 from which the scale has been removed by the grinding process with a small amount of grinding without performing the pickling process, the stainless cold-rolled steel is produced. It becomes possible to reduce the manufacturing cost of a belt.

  Moreover, in the manufacturing method of the stainless steel strip of this embodiment, in the shot blasting equipment 8, the shot particle projection speed is in the range of 60 m / sec to 100 m / sec, and the shot particle projection distance is in the range of 300 mm to 1000 mm. Each set shot blasting process was performed on the surface of the stainless hot-rolled steel strip 18, but the present invention is not limited to this. That is, the shot blasting condition may be such that the shot particle projection speed is out of the range of 60 m / sec to 100 m / sec and the shot particle projection distance is out of the range of 300 mm to 1000 mm. However, as in the method of manufacturing the stainless steel strip of the present embodiment, the shot blasting conditions are such that the shot particle projection speed is in the range of 60 m / sec to 100 m / sec, and the shot particle projection distance is 300 mm to 1000 mm. Setting within the range, the shot particle projection speed is outside the range of 60 m / sec to 100 m / sec, and the shot particle projection distance is outside the range of 300 mm to 1000 mm, The scale formed on the surface of the stainless hot-rolled steel strip 18 can be further removed, which is preferable.

  Furthermore, in the method for producing a stainless steel strip of the present embodiment, steel shot is used as shot particles, and a metal-based material is used as the material of shot particles, but the present invention is not limited to this. That is, as the material of the shot particles, for example, a ceramic material such as silicon carbide (SiC), a resin material such as nylon, a plant material such as a wood chip, or a glass material such as glass beads may be used.

Hereinafter, using the same production line as the production line 1 of the present embodiment, the conventional example in which the pickling treatment was performed, and the present invention and the comparative example in which the pickling treatment is not performed, three types of stainless hot-rolled steel strips On the other hand, scale removal processing is performed and the experimental results are shown.
As the stainless hot-rolled steel strip, a stainless hot-rolled steel strip having a thickness of 3 mm formed from SUH409 and annealed in a box-type annealing furnace after hot rolling is used. The chemical composition of SUH409 is shown in Table 3 Ingredients.

In Table 3, as in Table 1 described above, each component is shown in mass%.
Various conditions of this experiment are as follows. The average particle size of shot particles is 0.4 mm for the conventional example, 0.2 mm for the present invention example, 0.4 mm for the comparative example, and the shot particle projection density is 80 kg / m ² , and the shot particle projection speed was 65 m / sec for all three examples. Moreover, the conveyance speed of the stainless hot-rolled steel strip was set to 30 m / min in all three examples.

In addition, the grinding treatment of the present invention example and the comparative example is performed by using a stainless steel hot rolled steel with a brush roll in which a rod-like body having a diameter of 3 mm or more containing abrasive grains is radially attached to a roll shaft and the diameter is 450 mm. While rotating at a speed of 1200 r / min in the direction opposite to the belt conveyance direction, cooling water was supplied between the stainless hot-rolled steel strip and the brush roll.
Further, in the conventional example, unlike the examples of the present invention and the comparative example, a known pickling treatment was performed on the stainless hot-rolled steel strip after the shot blast treatment.

In the pickling treatment, after pickling treatment at 80 ° C. and 60 sec using 20 mass% sulfuric acid, an acid at 80 ° C. and 30 sec using a mixed acid of 15 mass% nitric acid and 3 mass% hydrofluoric acid. Washing was performed.
After conducting an experiment under each of the above conditions, the presence or absence of scale residue was confirmed on both the front and back surfaces of the entire length in the longitudinal direction for all three examples of the stainless hot-rolled steel strip. As a result, scale residue was confirmed in the comparative example, but scale residue was not confirmed in the present invention example and the conventional example.

Therefore, in the example of the present invention, it was confirmed that the scale formed on the surface of the stainless hot-rolled steel strip can be removed without performing the pickling treatment.
Furthermore, the corrosion resistance evaluation test was done with respect to the present invention example and the conventional example in which no scale residue was confirmed.
As the corrosion resistance evaluation test, an accelerated corrosion test using salt spray is applied, and the conditions of the accelerated corrosion test are as follows. After the following cycle is repeated 30 times, the corrosion resistance is determined based on the corrosion condition of the stainless hot-rolled steel strip after the test. evaluated.
Salt spray: 40 ° C and 1Hr
Drying: 60 ° C and 2Hr
Wet: 40 ° C and 2Hr

FIG. 4 shows the results of the corrosion resistance evaluation test. 4A shows a conventional example, and FIG. 4B shows an example of the present invention.
As shown in FIG. 4, it was confirmed that even in the present invention example in which the pickling treatment is not performed, the corrosion resistance is almost the same as that in the conventional example in which the pickling treatment is performed. .
Therefore, in the present invention example, it is possible to remove the scale formed on the surface of the stainless hot-rolled steel strip without performing pickling treatment, and it is confirmed that the corrosion resistance is not deteriorated as compared with the conventional example. It was confirmed that it is very effective from the viewpoint of reducing environmental impact.

It is a figure which shows the structure of the manufacturing line of the stainless steel strip of this invention. It is a figure which shows the relationship between the descaling amount, the average particle diameter of shot particles, and average roughness Ra. It is a figure which shows the relationship between the surface roughness of the sample steel strip after a shot blast process, and the measurement result of the scale which remains on the surface of the cold-rolled sample steel strip. It is a figure which shows the result of a corrosion resistance evaluation test.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Production line 2 Dispensing machine 4 Welding machine 6 Incoming looper 8 Shot blasting equipment 10 Brush grinding device 12 Pickling device 14 Outlet looper 16 Winder 18 Stainless steel hot-rolled steel strip

Claims (4)

A stainless steel strip manufactured by impacting shot particles on the surface of a hot-rolled stainless steel strip and then grinding the surface of the stainless steel strip collided with the shot particles,
The average particle size of the shot particles is in the range of 0.15 mm to 0.25 mm,
Projection density of the shot ^particles, Ri range der of ^{80kg / m 2 ~200kg / m 2} ,
The shot particle projection speed is in the range of 60 m / sec to 100 m / sec,
Projection distance of the shot particles, stainless steel strip, characterized in der Rukoto range of 300Mm～1000mm.   The surface of the stainless steel strip collided with the shot particles is ground, and then the rolled stainless steel strip is cold rolled without pickling. Stainless steel strip. A method for producing a stainless steel strip, which comprises grinding the surface of a stainless steel strip collided with shot particles after colliding shot particles with the surface of a hot-rolled stainless steel strip,
The average particle size of the shot particles is in the range of 0.15 mm to 0.25 mm,
A projection density of the shot ^particles, and in the range of ^{80kg / m 2 ~200kg / m 2} ,
The shot particle projection speed is in the range of 60 m / sec to 100 m / sec,
The method for producing a stainless steel strip, wherein a shot distance of the shot particles is within a range of 300 mm to 1000 mm . 4. The stainless steel strip according to claim 3 , wherein the surface of the stainless steel strip on which the shot particles collide is ground and then cold-rolled without pickling treatment of the ground stainless steel strip. Manufacturing method.