JP3451830B2 - Ferritic stainless steel sheet excellent in ridging resistance and workability and method for producing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ferritic stainless steel and a method for producing the same, and in particular, aims to improve ridging resistance and workability by improving its micro texture.

[0002]

BACKGROUND OF THE INVENTION Ferritic stainless steel is widely used in various fields such as kitchen appliances and automobile parts because it is excellent in stress corrosion cracking resistance and inexpensive. However, it has a drawback in that it is inferior in ridging resistance and press workability as compared with austenitic stainless steel. Therefore, many studies have been conducted to improve the ridging resistance and press workability of ferritic stainless steel (substantially improve the r value).

The research so far has focused on the macroscopic texture in the steel sheet, that is, the texture determined by X-ray diffraction as an average distribution of a few millimeters squares, the integrated intensity ratio and the axial density function. Therefore, it was concluded that the ridging resistance and the press workability can be improved by increasing the {111} orientation and decreasing the {100} orientation.

For example, in Japanese Patent Laid-Open No. 3-264625, an excellent press can be obtained by adding Ti and Nb to ferritic stainless steel in combination and setting the X-ray integrated intensity ratio to (222) / (200) ≧ 5. It is reported that moldability is obtained. Further, in JP-A-53-48018, (C + N) is set to 0.030% or less, an appropriate amount of Ti is added, and hot rolling-annealing-
By controlling each condition of cold rolling, {554} <2
It has been reported that the accumulation in the 25> direction is strengthened and the ridging resistance and press workability are improved.

The inventors of the present invention previously disclosed in Japanese Unexamined Patent Publication No. 7-2684.
In Japanese Patent Laid-Open No. 61-61, as a means for improving ridging resistance and press workability, a method of performing rough rolling under a large lubrication pressure was proposed. By this method, the ridging resistance and the press workability can be considerably improved. However, the above method is intended to improve the characteristics by promoting recrystallization and randomizing the crystal orientation distribution, and is not intended to optimally control the crystal orientation distribution.

In any case, the conventional technical idea for improving ridging resistance and press workability is limited to the macroscopic texture control measured by X-ray diffraction.
However, in many cases, the ridging phenomenon cannot be explained by the macroscopic texture determined by X-ray diffraction. In this regard, an example of an experiment conducted by the present inventors is shown in FIG. According to the figure, it is considered that the steel A and the steel B have almost the same texture in the X-ray diffraction result. However, when comparing the ridging height and the r value, r
Although the values are almost the same for both steels, there is a large difference in ridging height. This indicates that the r value can be evaluated by the degree of accumulation of macroscopic texture in the {111} direction, but the ridging resistance cannot be evaluated by macroscopic texture. Therefore, it is not possible to obtain a steel excellent in ridging resistance and press workability only by controlling the macro texture.

Therefore, recently, attempts have been made to control the structure by incorporating the concept of colonies, which are aggregates of the same crystal orientation. Here, a colony, for example, a {hkl} colony, is a crystal group in which the directional vector perpendicular to the rolling surface of each adjacent crystal is within a predetermined angle from the <hkl> direction.

As a method of reducing the colony size and improving ridging, there is a method of lengthening the time between passes of the rough rolling which has been conventionally performed in about 10 to 30 seconds. For example, in JP-A-61-163216, Al is 0.08 to 0.5 wt%.
Disclosed is a method for controlling the post-pass time of the rough rolling of the added ferritic stainless steel to 15 seconds or more and within 60, and limiting the finishing rolling temperature, the winding temperature and the cold rolling condition to a predetermined range. . In the above structure, addition of Al has an effect of promoting α → γ transformation and precipitation of AlN.
In addition, increasing the time between passes in the latter stage of rough rolling has an effect of promoting recrystallization in rough rolling, and at this time, the crystal orientation is randomized and finally the {11
1} and {100} colony sizes are reduced. As a result, ridging can be improved by adopting the method disclosed in Japanese Patent Laid-Open No. 61-163216. However, since good press workability cannot be obtained if the crystal orientation remains random, the {111} orientation required for press workability is the reduction of solid solution N due to precipitation of AlN in the subsequent cold-annealing step. The technical idea in the publication is to increase the shear deformation amount by reducing the large-diameter roll rolling.

However, in a steel sheet whose crystal orientation is once randomized, {1 is obtained only by the subsequent cold rolling-annealing step.
There is a limit to increase the 11} orientation without colonization, and it is difficult to obtain an ultra-deep-drawn stainless steel sheet having excellent ridging resistance and an r value of more than 1.5. Also,
Since this publication is directed to stainless steel such as SUS 430 having a two-phase structure of (α + γ) during rough rolling, there is a problem that it cannot be applied to ferrite single-phase steel. Furthermore, it takes a long time between passes for rough rolling more than twice, which is problematic in terms of productivity, and strict control of all processes from the slab heating temperature to the cold rolling process is a production control. It is not preferable from the point of view.

In "Iron and Steel No. 76 (1990) No. 9", an attempt is made to measure individual crystal orientations to clarify the mechanism of ridging. That is, Al addition
The time between passes during rough rolling of SUS 430 is 10 seconds (Sample A), 30
Second (Sample B) was prepared and ECP (Electoron)
The crystal orientation distribution is measured by the channeling pattern) method. As a result, the ridging height was lower in the sample B with the interpass time of 30 seconds. The reason is as follows.
The non-uniform distribution of the {100} <011> colonies after rough rolling with respect to the plate thickness center line is mentioned. Further, according to the measurement result of the crystal orientation distribution by the ECP method, the size and the existence frequency of the colonies after rough rolling and after cold rolling annealing are lower in the sample B having excellent ridging resistance than the sample A. . Therefore, it is said that increasing the pass time of rough rolling brings about randomization of crystal orientation and contributes to improvement of ridging.

However, in this paper, as described in the text, since the crystal orientation distribution of the recrystallized plate (the plate after cold rolling and annealing) was not investigated in detail, the size and frequency of colonies were observed. Although there is a suggestion that the lower the value, the better the ridging property, the relationship between the ridging and the colony is not clarified. Further, since the ridging of the recrystallized plate has a width of several hundred μm to several mm in the width direction, it is necessary to measure the crystal orientation at least a few mm in the width direction.In the above paper, 250 μm × 120 μm However, there is a serious defect that the measurement area is narrow in order to clarify the relationship between ridging and colonies.

[0012] In addition, as a paper investigating the relationship between ridging and colonies, "Materials Science Forim, Vol.
157-162 (1994). P1137 ”. In this, EBS
D (Electoron Backscattering Diffraction) method 2
Measurements were made in the range of 00 μm width × 125 μm thickness. However, this method also has a problem that the measurement result is not performed for each crystal because the measurement range is narrow and the measurement is performed in 5 μm steps.

On the other hand, there is an attempt to improve press workability or ridging resistance from the viewpoint of rolling speed. For example, in Japanese Patent Laid-Open No. 4-210425, the strain rate of rough rolling is set to 10
By slowing down to (s ^-1 ) or less, it is said that the colonies of the texture that inherit the coagulation tissue can be randomized, and as a result, the ridging property is improved. Then, the reduction of the strain rate may be achieved by slowing the rolling rate. However, when the crystal orientation is randomized, there is a problem that press workability is significantly deteriorated. Further, the reduction of rolling speed is not preferable from the viewpoint of productivity.

As a method of increasing the rolling speed,
Japanese Unexamined Patent Publication No. 6-271944 discloses that by setting the rolling speed to 600 mpm or more in a ferrite single phase region of 1100 ° C. or less, both r value and ridging resistance are improved. However, the rolling speed of 600 mpm or more is a technique in finish rolling and is difficult in rough rolling. Here, the rolling speed of general rough rolling is about 50 to 150 mpm.

[0015]

As described above, all of the conventional techniques attempt to improve ridging by reducing the colony size and randomizing the crystal orientation distribution. The size of the colony and its distribution in the steel sheet have hardly been clarified, and the relationship between the colony and ridging has not been speculated.

The present invention advantageously solves the above-mentioned problems. Based on the results, the ferritic stainless steel excellent in ridging resistance and press workability can be produced by solving the mechanism of ridging. It is intended to be proposed with the method.

[0017]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present inventors have measured the individual crystallographic orientations over a wide range and conducted a detailed investigation on the relationship between ridging and crystallographic orientation distribution. As a result, in order to achieve both ridging resistance and press workability, the distribution of {111} -oriented colonies in the width direction is important rather than the randomization of crystal orientations, which is completely different from the conventional method of utilizing colonies. We have found that the above problems can be advantageously solved under the opposite technical idea. The present invention is based on the above findings.

That is, the gist of the present invention is as follows. 1. A ferritic stainless steel plate, in which the size in the plate width direction of the {111} orientation colony defined below is on a surface (ND surface) perpendicular to the plate surface normal at the plate thickness center.
A ferritic stainless steel sheet excellent in ridging resistance and workability, characterized in that the colony has a proportion of 100 to 1000 μm in the whole width of the plate and 30 to 95%. Note {111} orientation colony: A crystal group in which the direction vector perpendicular to the rolling surface of each adjacent crystal is within 15 ° from the <111> direction.

2. In the above 1, the composition of the steel sheet is
Cr: 10 to 35 mass%, C: 0.0300 mass% or less, N: 0.0600
At least one selected from Ti, Nb, Ta, Zr, B and Al, including mass% or less: 2 × (C + N) or more,
A ferritic stainless steel sheet containing 0.5 mass% or less.

3. In addition to the steel composition of 2 above, at least one selected from Mo, Cu and Ni: 0.1 to 0.5 mass
%, A ferritic stainless steel sheet containing 100%.

4. Cr: 10 to 35 mass%, C: 0.0300 mass
% Or less, N: 0.0600 mass% or less, and Ti, Nb, T
at least one selected from a, Zr, B and Al:
A steel slab containing 2 × (C + N) or more and 0.5 mass% or less is hot-rolled, then cold-rolled, and then finish-annealed to produce a ferritic stainless steel sheet. In the process, at least one pass has a rolling temperature of 970 to 1150 ° C., a friction coefficient of 0.3 or less, a rolling reduction of 40 to 75%, a rolling speed of y (mpm), and a time between passes after rolling: x ( Is performed under conditions satisfying the following formula, and in the subsequent finish rolling step, at least one pass is performed at a rolling temperature of 600 to 950 ° C. and a rolling reduction of 10 to 40%. A method for producing a ferritic stainless steel sheet having excellent ridging resistance and workability. Note y = 50 / (x−5) +150, 5 <x ≦ 45, 150 <y ≦ 30
0, where x: time between passes (seconds) y: rolling speed (mpm)

5. In the above 4, the composition of the steel slab is
Furthermore, the method for producing a ferritic stainless steel sheet containing at least one selected from Mo, Cu and Ni: 0.1 to 0.5 mass%.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Experimental results leading to the invention will be described below. C: 0.0080 mass%, N:
0.0095mass%, Cr: 16.5mass%, Si: 0.18mass%, Mn:
0.21mass% and S: 0.0024mass%, and Ti
Of stainless steel containing various alloys in the range of up to 0.25 mass% was heated, heated to 1200 ° C, and then hot-rolled by 6-pass rough rolling and 7-pass finish rolling to obtain a plate thickness of 4.0 mm hot rolled sheet. Here, the rolling reduction in the 5th pass of the rough rolling is 35 to 50%, the rolling temperature is 1060 ° C, and the friction coefficient is 0.
2. The rolling speed of the 5th pass of rough rolling is 210 mpm, the time between passes of the 5th and 6th passes is 21 seconds, and the rolling reduction of the final pass of finishing rolling is 10 to 30% and the rolling temperature is 750 ° C. did.
Next, after hot-rolled sheet annealing at 800 to 950 ° C for 60 seconds, cold rolling was performed, and then finish rolling at 880 to 950 ° C for 60 seconds to obtain a cold rolled annealed sheet with a thickness of 0.7 mm. .

The influence of the {111} oriented colony width on the ridging height and r value of the cold rolled annealed sheet thus obtained was examined and the results are shown in FIG. As is clear from the figure, the r-value suddenly increases when the {111} colony width is 100 μm or more and tends to be saturated immediately, while the ridging resistance is rapid when the {111} orientation colony width exceeds 1000 μm. Turned out to be worse. Note that {111}
The colony width is defined by EBSD (Electron Back Scattering Di
The crystal grain group in which the direction vector perpendicular to the rolling surface of the adjacent crystal grains is within 15 degrees from the <111> direction was regarded as a {111} oriented colony.

FIG. 3 shows the results of measuring the crystal orientation over the width of the steel sheet of about 4 mm. The size of the {111} oriented colonies in the width direction of the sheet is 100 to 1000 μm and {1}.
When the total length of the 11} -oriented colonies in the plate width direction was 30% or more of the measured length (1000 μm or more), both ridging resistance and press workability were excellent. Thus, in order to investigate the relationship between ridging and crystal orientation distribution, a wide range measurement in millimeters (mm) is indispensable.

Further, the width of the {111} orientation colony is 350.
In the case of μm (invention example) and 1200 μm (comparative example), (2
(00) The pole figure is shown in comparison with FIG. 1 above, and although the macroscopic texture distributions obtained by X-ray diffraction are the same in both cases, there is a large difference in the ridging height. There is. Therefore, in order to obtain a steel excellent in both r-value and ridging resistance, it can be said that fine control of the crystal orientation distribution is indispensable.

The r value and the ridging height were measured as follows.・ After applying a tensile strain of 15% using r value JIS No. 13B test piece,
The r value in each direction was calculated by the three-point method and expressed as an average value by the following formula. r value = (r _L + 2r _D + r _C ) / 4 where r _L , r _D , and r _C are the r values in the rolling direction, the direction of 45 ° to the rolling direction, and the direction of 90 ° to the rolling direction, respectively. Represents・ Rising height After applying a tensile strain of 20% to a JIS No. 5 test piece taken from the rolling direction, the ridging height (μm) was measured with a surface roughness meter.

[0028]

Next, the reason why the composition and crystal orientation distribution of the ferritic stainless steel in the present invention are limited to the above range will be described. Cr: 10 to 35 mass% Cr is an essential element for ensuring the corrosion resistance as stainless steel. If the amount is less than 10 mass%, the corrosion resistance will be insufficient, while if it exceeds 35 mass%, the workability will decrease, so the content is 10 to 35 mass% (preferably 14 to 19 mass%).
And

C: 0.0300 mass or less C is an element that lowers the r value and the corrosion resistance, and is 0.03
When it exceeds 00mass%, its effect becomes remarkable, so 0.0300ma
ss% or less. In addition, considering the current production limits,
The addition amount of C is preferably about 0.0005 to 0.0200 mass%.

Si: 1.0 mass% or less Si is a useful element for deoxidation, but excessive addition causes hardening of the steel sheet and deterioration of ductility, so the content is 1.0 ma.
ss% or less (preferably 0.05 to 0.70 mass%).

Mn: 1.0 mass% or less Mn is an element effective for improving hot workability and toughness of welded portions. For this purpose, addition of 1.0 mass% or less is sufficient, and preferably 0.05 to 0.70 mass%.

S: 0.0100 mass% S is an element that deteriorates corrosion resistance, and it is desirable to reduce S as much as possible. If S exceeds 0.0100 mass%, the corrosion resistance is significantly deteriorated, so the upper limit is made 0.0100 mass%. It is preferably 0.0050 mass% or less.

Ti, Nb, V, Ta, Zr, B and / or A
l: 2 × (C + N) or more and 0.5 mass% or less All of these elements are elements that are useful for fixing C and N as carbonitrides and developing the (111) orientation. If the effect is less than twice (C + N), the solid solution C,
N is not sufficient because a large amount of N is present in the steel. On the other hand, excessive addition thereof is not preferable because Ti, Nb, etc. in the solid solution state increase and the r value decreases. Therefore, the range of addition of the above elements is 2 × (C
+ N) or more and 0.5 mass% or less. Preferably 5x
It is at least (C + N) and at most 0.3 mass%.

Mo, Cu and / or Ni: 0.1 to 5.0 mass
% All of these elements effectively contribute to the improvement of corrosion resistance, but if less than 0.1 mass%, their addition effect is poor, while
If added in excess of 5.0 mass%, the workability will be greatly reduced, so 0.1 to 5.0 mass% is used. Preferably 1.0 ~
It is 3.0 mass%.

Size of {111} -oriented colonies in the plate width direction: 100 to 1000 μm A feature of the present invention is that the {111} -oriented colonies are positively used. If the size of the {111} oriented colony in the plate width direction is less than 100 μm, sufficient press workability cannot be obtained as shown in FIG. On the other hand, {111}
When the size of the orientation colony in the plate width direction exceeds 1000 μm, this area and other areas (previously considered {10
The difference in the plastic deformation behavior is notably limited to that of the region having the 0} orientation) and a large waviness occurs in the steel sheet. Therefore, the size of the {111} -oriented colonies in the plate width direction was limited to the range of 100 to 1000 μm. The preferable range is 200 to 600 μm.

Proportion of the {111} -oriented colonies in the entire plate width: 30 to 95% If the total length of the {111} -oriented colonies in the plate width direction is less than 30% of the total plate width, sufficient press workability is obtained. Can't get If it exceeds 95%, the size of the {111} oriented colony in the plate width direction often becomes 1000 μm or more, in which case the ridging resistance deteriorates. Therefore, {111}
The ratio of the orientation colony to the whole plate width was limited to the range of 30 to 95%. The preferred range is 40-80%.

If the size of the {111} -oriented colony in the plate width direction satisfies the above requirements, it is possible to obtain a ferritic stainless steel having excellent ridging resistance and workability. By combining with, it is possible to more easily obtain a ferritic stainless steel having excellent ridging resistance and workability, which point will be described.

The rough rolling step serves to make the slab cast structure finer and plays an extremely important role in controlling the crystal orientation distribution. According to the present invention, the crystal orientation distribution is randomized as in the conventional case and the condition for reducing the colony is not
The rough rolling conditions for developing 1} orientation colonies are given.

Rolling temperature of rough rolling: 970 to 1150 ° C. If the rolling temperature is less than 970 ° C., the strain is concentrated on the surface layer of the steel sheet even if lubrication is carried out.
Many colonies other than the azimuth colony will be present. On the other hand, when the rolling temperature exceeds 1150 ° C., recovery is the main component, so that {100} oriented colonies remain in the hot-rolled sheet, degrading both workability and ridging resistance. Therefore, the rolling temperature for rough rolling must be 970 to 1150 ℃. The preferable temperature range is 1000 to 1100 ° C.

Rolling reduction of rough rolling: 40 to 75% In order to distribute the colonies of {111} orientation of 100 μm or more in the plate width direction, the rolling reduction must be 40% or more for at least one pass of rough rolling. . On the other hand, with current equipment, it is difficult to achieve a rolling reduction of more than 75% per pass in rough rolling. Therefore, the rolling reduction of the rough rolling is limited to the range of 40 to 75%. The preferable range is 50 to 60%.

Friction coefficient of rough rolling: 0.3 or less When the friction coefficient of rough rolling exceeds 0.30, the strain distribution due to rolling is biased toward the surface layer, making it difficult to set the plate width orientation size of the {111} orientation colony to 100 μm or more. Becomes Therefore, the friction coefficient of rough rolling needs to be 0.30 or less. It is preferably 0.20 or less. Any method may be used as a method for reducing the friction coefficient.

Relationship between Rolling Speed y (mpm) and Pass Time x (sec) It is necessary to precisely control the rough rolling speed and the pass time.
It is the most important factor in developing {111} oriented colonies. Taking a long time between passes is effective for promoting recrystallization of the steel sheet, but when combined with a simple large reduction, the crystal orientation becomes random as described above, and rather {1
11} Orientation inhibits the development of colonies. On the other hand, when a large amount of lubrication reduction rolling is performed at a high speed with an appropriate time between passes, the crystal orientation tends to form {111} oriented colonies. Figure 4
The results of investigating the effects of the rolling speed and the time between passes on the size of the {111} oriented colonies in the plate width direction are shown in FIG. As is clear from the figure, rolling speed: y (mp
m) and the time between passes: x (seconds), the relation y = 50 / (x−5) +150, 5 <x ≦ 45, 150 <y ≦ 30
It is possible to control the {111} -oriented colonies to have an appropriate size within a range satisfying 0. The preferred rolling speed is
180-250mpm, rolling time is 15-40 seconds.

Finishing rolling temperature: 600 to 950 ° C. If the rolling temperature in finishing rolling is less than 600 ° C., it is difficult to secure a rolling reduction of 10% or more, and the roll wear becomes severe. On the other hand, if the rolling temperature exceeds 950 ° C, {11
The size of the 1} orientation colony in the plate width direction tends to be less than 100 μm. Therefore, the temperature range for finish rolling is 600 to 95.
The temperature was 0 ° C. The preferred temperature range is 700-850 ° C.

Finishing rolling reduction ratio: 10 to 40% When the reduction ratio is less than 10%, a large amount of colonies other than the {111} orientation colonies are present, and the workability and ridging resistance are significantly deteriorated. On the other hand, rolling over 40% leads to poor biting, poor shape, and deterioration of steel sheet surface properties. Therefore,
The rolling reduction in finish rolling should be 10-40%. A preferable reduction rate is 20 to 35%.

[0045]

EXAMPLE Steels C to P having the composition shown in Table 1 were smelted into slabs, heated to 1200 ° C., and then hot-rolled by 6-pass rough rolling and 7-pass finish rolling. Then, a hot rolled sheet having a sheet thickness of 4.0 mm was obtained. At this time, as shown in Tables 2 and 3, the rolling reduction, the rolling temperature, the friction coefficient, the rolling speed, and the interpass time in the fifth pass of the rough rolling were variously changed.
The rolling reduction and rolling temperature of the final pass of finish rolling were also changed. Next, hot-rolled sheet is annealed at 800-950 ° C for 60 seconds, cold-rolled, then 880-950 ° C,
After 60 seconds of finish rolling, a cold rolled annealed plate with a plate thickness of 0.7 mm was obtained. Tables 2 and 3 show the results of an examination of the width direction size, r value and ridging of the {111} oriented colonies of the product plate thus obtained. Note that {111}
The size of the azimuth colony in the plate width direction is 3 to 10 mm in width and 1 to 2 mm in the ND plane centered on the plate thickness by the EBSD method.
Was measured over the range. Further, the r value and the ridging height were measured by the method described above.

[0046]

[Table 1]

[0047]

[Table 2]

[0048]

[Table 3]

As shown in Tables 2 and 3, all the products obtained according to the present invention show excellent r value and ridging resistance as compared with the comparative examples.

[0050]

2. Description of the Related Art Thus, according to the present invention, by controlling the microscopic crystal orientation distribution, it is possible to stably obtain a ferritic stainless steel sheet having excellent ridging resistance and formability.

[Brief description of drawings]

1 is a (200) pole figure of Steel A and Steel B. FIG.

2] The size in the width direction of a {111} oriented colony is r
It is a graph showing the influence on the value and the ridging height.

FIG. 3 is a schematic diagram showing a crystal orientation distribution measured over a width of about 4 mm of a steel sheet.

FIG. 4 is a graph showing the influence of rolling speed and interpass time on the size of {111} oriented colonies in the plate width direction.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) C22C 38/00-38/60

Claims (5)

(57) [Claims] 1. A ferritic stainless steel plate, comprising:
In the plane (ND plane) perpendicular to the plate surface normal at the plate thickness center, the size in the plate width direction of the {111} orientation colony defined below is 100 to 1000 μm, and the ratio of the colony to the entire plate width Of 30-95% is a ferritic stainless steel sheet with excellent ridging resistance and workability. Note {111} orientation colony: A crystal group in which the direction vector perpendicular to the rolling surface of each adjacent crystal is within 15 ° from the <111> direction. 2. The steel sheet according to claim 1, wherein the composition of the steel sheet includes Cr: 10 to 35 mass%, C: 0.0300 mass% or less, N: 0.0600 mass% or less, and Ti, Nb, Ta, Zr, B and A ferritic stainless steel sheet containing at least one selected from Al: 2 × (C + N) or more and 0.5 mass% or less. 3. The steel composition according to claim 2, further comprising at least one selected from Mo, Cu and Ni: 0.1 to 0.5 mass.
%, A ferritic stainless steel sheet containing 100%. 4. Cr: 10 to 35 mass%, C: 0.0300 mass% or less, N: 0.0600 mass% or less, and at least one selected from Ti, Nb, Ta, Zr, B and Al: 2 A steel slab containing x (C + N) or more and 0.5 mass% or less is hot-rolled, then cold-rolled, and then finish-annealed to produce a ferritic stainless steel sheet. In at least one pass, rolling temperature: 970 to 1150 ° C, friction coefficient: 0.3 or less, rolling reduction: 40 to 75%, and rolling speed: y
(Mpm) and the time between passes after rolling: x (seconds) are performed under the condition that the following formula is satisfied, and in the subsequent finishing rolling step, at least one pass is performed at a rolling temperature of 60.
A method for producing a ferritic stainless steel sheet having excellent ridging resistance and workability, which is performed at 0 to 950 ° C and a rolling reduction of 10 to 40%. Note y = 50 / (x−5) +150, 5 <x ≦ 45, 150 <y ≦ 30
0 where x: time between passes (seconds) y: rolling speed (mpm) 5. The steel slab composition according to claim 4, wherein
Furthermore, the method for producing a ferritic stainless steel sheet containing at least one selected from Mo, Cu and Ni: 0.1 to 0.5 mass%.