JP4397772B2 - Manufacturing method of ferritic stainless steel sheet with excellent workability - Google Patents

Description

The present invention relates to a method for producing a ferritic stainless steel sheet as a material for a molded product that requires particularly excellent formability.

  Ferritic stainless steel sheets are used in a wide range of fields such as home appliances, kitchen equipment, and electronic equipment. However, since the formability is inferior to that of an austenitic stainless steel sheet, there are cases where the use is limited. For example, in recent years, the application of a stainless steel plate as a material used for fuel tanks and pipes of automobiles and motorcycles is being studied. Corrosion resistance in the fuel environment and high workability for molding into fuel tanks and pipes are required. These internal environments can be said to be very harsh because organic acids produced by the deterioration of gasoline promote corrosion of steel materials. For this reason, surface-treated steel sheets have been used as steel materials for dealing with corrosive environments on the inner and outer surfaces. However, there have been problems such as long-term corrosion resistance, weldability, and environmental problems due to elution of the plating layer. Although attempts have been made to use resins, there are problems from the viewpoint of fuel permeability and recycling. Furthermore, in recent years, the warranty period of fuel parts is being extended from 10 years to 15 years from the viewpoint of environmental protection, and replacement of the above-mentioned surface-treated steel sheets and resins is required.

  Austenitic stainless steel sheets have the advantage of superior workability and corrosion resistance compared to ferritic stainless steel sheets, but they are costly and have low reliability against stress corrosion cracking in the salt environment of the outer surface. was there. On the other hand, the ferritic stainless steel sheet has the advantage that stress corrosion cracking, which is a drawback of the austenitic stainless steel sheet, does not occur, but it is difficult to ensure formability to be processed into a fuel part having a complicated shape.

  Several ideas have been made to solve the problems related to formability of the ferritic stainless steel sheet as described above. For example, for fuel parts that are severely processed, Patent Document 1 discloses a method for defining the linear pressure in the finish rolling process in the hot rolling process and a method for defining the hot rolled sheet annealing conditions. Patent Document 2 discloses a method of defining an X-ray integral intensity ratio and a temperature and rolling reduction in hot rolling rough rolling, and performing intermediate annealing in addition to hot rolling sheet annealing. These are to improve the r value, but when the product thickness is about 0.8 mm and the cold rolling reduction ratio is relatively large, it is not sufficient for thicker than 1 mm thickness. . The reason for this is considered to be that the crystal grain size becomes coarse when the hot-rolled sheet annealing is performed, and the effect of refining the structure before cold rolling cannot be obtained. Furthermore, these manufacturing methods have a problem that efficient steel sheet manufacturing cannot be performed.

  Patent Documents 3 to 6 disclose ones that define the r value and those that define the elongation at break. However, there are cases where the fuel component cannot be processed only by improving the r value. Moreover, there are cases where cracks occur at the overhanging portion, and there are cases where molding cannot be performed for complex processing only by improving the elongation at break. This is because the n value, which is an index of work hardening, is more important than the uniaxial tensile elongation at break when multiaxial machining is actually performed.

  As described above, the subject of the present invention is premised on a thin plate with a thickness of about 0.8 mm, but in a fuel tank, a relatively thick steel plate with a thickness of about 1.6 mm is used from the viewpoint of internal pressure. Sometimes it is done. If the plate thickness is increased, the cold rolling reduction ratio cannot be secured high, which is disadvantageous for improving the r value. According to the above disclosure, it has been impossible to ensure the formability of such a thick material.

JP 2002-363712 A JP 2002-285300 A JP 2002-363711 A JP 2002-97552 A JP 2002-60973 A JP 2002-60972 A

  An object of the present invention is to solve the problems of the known techniques and efficiently produce a ferritic stainless steel sheet having excellent workability.

  In order to solve the above-mentioned problems, the present inventors conducted detailed studies on the formability of ferritic stainless steel sheets from the viewpoints of components, structure in the manufacturing process, and crystal orientation. As a result, under extremely severe press forming such as fuel parts, the processing characteristics of ferritic stainless steel sheets require that the orientation of crystal orientation be uniform in the thickness direction of the steel sheet, and the thickness from thin to thick It has been found that even if the average r value × n value is 0.4 or more, even parts having complicated shapes can be processed.

The gist of the present invention for solving the above problems is as follows.
( 1 ) In mass%, C: 0.001 to 0.005%, Si: 0.01 to 0.20%, Mn: 0.01 to 0.20%, P: 0.01 to 0.03 %, S: 0.0005-0.0100%, Cr: 16-25%, N: 0.001-0.020%, Mo: 0.5-2.0%, Ti: 0.05-0. When hot-rolling a stainless steel slab containing 25% and B: 0.0002 to 0.0030% and the balance being Fe and inevitable impurities, the slab heating temperature is 1100 to 1200 ° C. Continuous rolling in which the ratio of the rolling reduction to the total rolling reduction of finish rolling (total rolling reduction of rough rolling / total rolling reduction of finishing rolling) is 0.8 to 1.0, and finish rolling finish temperature is 700 to 900 ° C. Winding at 650 to 850 ° C., recrystallized grain size is 50 μm or less, and recrystallization rate is 5% or more and 90% After obtaining a hot rolled sheet that is
The hot-rolled sheet annealing is omitted, and after performing cold rolling with a rolling reduction of 30% or more by unidirectional rolling using a roll having a diameter of 400 mm or more , heat treatment is performed at 750 to 870 ° C., and the recrystallized grain size is After obtaining an intermediate annealed plate having a recrystallization rate of 30% or less and a recrystallization ratio of 50% or more and 100% or less, and subsequently performing cold rolling , heat treatment is performed at 900 to 1050 ° C. in the finish annealing step, 8. A method for producing a ferritic stainless steel sheet excellent in workability , characterized by adjusting to 8 .
(2) The slab is further in terms of mass%, Al: 0.005 to 0.10%, Ni: 0.5 to 1.0% , Cu: 0.5 to 3.0%, V: 0.00. The method for producing a ferritic stainless steel sheet having excellent workability according to ( 1 ), comprising one or more of 05 to 1.0% and Mg: 0.0002 to 0.0030%.

  As is apparent from the above description, according to the present invention, a ferritic stainless steel sheet having excellent formability can be efficiently provided without requiring new equipment.

The reason for limitation of the present invention will be described below. As an index of workability, there are an r value that is an index of deep drawability and an n value that is an index of stretchability, and the crystal orientation of steel acts. The higher the both, the larger the moldable size, but as a result of examining the processing state of various parts in detail, it was found that if the average r value × average n value is 0.4 or more, molding is possible. . FIG. 1 shows r values, n values, crystal orientations and r of steels (17% Cr-0.1% Ti-1.2% Mo-0.003% C-0.008% N) manufactured by various manufacturing methods. Indicates the relationship of values. Here, EBSP (Electron Back-Sccetering Difraction Pattern) is used as the crystal orientation, the orientation of each crystal grain is measured for the total thickness of the product plate, and the <111> direction and <554> direction of the crystal grain are on the rolling surface. The area ratio of crystal grains within a direction perpendicular to the direction and 15 ° was measured. Evaluation of the r value is obtained by collecting JIS13B tensile test pieces from cold-rolled annealed plates and applying 15% strain in the rolling direction, the rolling direction and 45 ° direction, and the rolling direction and 90 ° direction (1). And the average r value was computed using (2) Formula.
r = ln (W ₀ / W) / ln (t ₀ / t) (1)
Here, W ₀ is the plate width before tension, W is the plate width after tension, t ₀ is the plate thickness before tension, and t is the plate thickness after tension.
Average r value = (r ₀ + 2r ₄₅ + r ₉₀ ) / 4 (2)
Here, r ₀ is the r value in the rolling direction, r ₄₅ is the r value in the rolling direction and the 45 ° direction, and r ₉₀ is the r value in the direction perpendicular to the rolling direction. The n value is evaluated by taking a JIS No. 13 B tensile test piece from a cold-rolled annealed plate and conducting a tensile test in the rolling direction, the rolling direction and 45 ° direction, and the rolling direction and 90 ° direction, and at 5 to 15% strain. The work hardening coefficient was calculated, and the average n value was calculated using equation (3).
Average n value = (n ₀ + 2n ₄₅ + n ₉₀ ) / 4 (3)
Here, n ₀ is the n value in the rolling direction, n ₄₅ is the n value in the rolling direction and the 45 ° direction, and n ₉₀ is the n value in the direction perpendicular to the rolling direction. Thus, the r value × n value is 0.4 or more because the <111> direction of the crystal grains and the area ratio of the crystal grains in which the <554> direction is within 15 ° with the direction perpendicular to the rolling surface It can be seen that this is the case where the sum of the values exists at a ratio of 60% or more.

  Next, the component range of steel will be described.

  Since C deteriorates moldability and corrosion resistance, the lower the content, the better. Therefore, the upper limit was made 0.005%. However, excessive reduction leads to an increase in refining costs, so the lower limit was made 0.001%. Furthermore, if considering the manufacturing cost and corrosion resistance, 0.002 to 0.003% is desirable.

  Si may be added as a deoxidizing element, and also improves oxidation resistance. However, since it is a solid solution strengthening element, the lower the content, the better, so the upper limit is 0.20%. did. On the other hand, in order to ensure oxidation resistance, the lower limit was made 0.01%. However, excessive reduction leads to an increase in refining costs, so 0.02 to 0.15% is desirable in consideration of the material.

  Since Mn is a solid solution strengthening element like Si, the lower the content, the better. Therefore, the upper limit was made 0.20%. On the other hand, excessive reduction leads to an increase in refining costs, so the lower limit was made 0.01%. Further, considering the material, the upper limit is preferably 0.15%.

  Since P is a solid solution strengthening element like Mn and Si, the lower the content, the better. Therefore, the upper limit was made 0.03%. However, excessive reduction leads to an increase in raw material cost, so the lower limit was made 0.01%. Further, if considering the manufacturing cost and corrosion resistance, 0.013 to 0.020% is desirable.

Since S is an element that degrades the corrosion resistance, the upper limit was made 0.0100%. On the other hand, in the case of Ti-containing steel, Ti ₄ C ₂ S ₂ is formed at a high temperature and contributes to the development of a texture that is superior in formability. Since this occurs from 0.0005%, the lower limit was set to 0.0005%. Furthermore, when considering refining costs and suppression of crevice corrosion when fuel parts are used, 0.0010 to 0.0060% is desirable.

  Cr is an element that improves the corrosion resistance, and if considering the environment of the fuel component, 16% or more is necessary. On the other hand, excessive addition becomes hard and deteriorates moldability, so the upper limit was made 25%. In addition, when considering the plate cost at the time of manufacturing due to the manufacturing cost and toughness deterioration, 17 to 23% is desirable.

  N, like C, deteriorates the formability and corrosion resistance, so the smaller the content, the better, and the upper limit was made 0.020%. However, excessive reduction leads to an increase in refining costs, so the lower limit was made 0.001%. Furthermore, if considering the manufacturing cost, workability, and corrosion resistance, 0.004 to 0.010% is desirable.

  Mo is an element that improves corrosion resistance, and is an element that is necessary for suppressing crevice corrosion, particularly when it has a crevice structure. If this effect is less than 0.5%, corrosion will occur on the inner and outer surfaces of the fuel component, so the lower limit was made 0.5%. On the other hand, if it exceeds 2.0%, the moldability is remarkably deteriorated and the manufacturability is deteriorated, so the upper limit was made 2.0%. Furthermore, if considering the manufacturing cost, 1.0 to 1.8% is desirable.

  Ti is an element added to combine with C, N, and S to improve corrosion resistance, intergranular corrosion resistance, and deep drawability. Since the C and N fixing action appears from 0.05%, the lower limit was made 0.05%. Moreover, since addition exceeding 0.25% hardens with solute Ti, the upper limit was made 0.25%. Furthermore, considering the manufacturing cost, 0.10 to 0.20% is desirable.

  B is an element that improves the secondary workability of the product by segregating at the grain boundaries. In order to prevent cracking especially in winter after being processed as a fuel part, it is necessary to add 0.0002% or more. However, excessive addition causes deterioration of workability and corrosion resistance, so the upper limit was made 0.0030%. Furthermore, if considering cost and ductility reduction, 0.0003 to 0.0010% is desirable.

  In some cases, Al is added as a deoxidizing element, and its action is manifested from 0.005%, so the lower limit was made 0.005%. Further, addition of 0.10% or more causes a decrease in elongation, deterioration of weldability and surface quality, so the upper limit was made 0.10%. Furthermore, if considering the refining cost, 0.01 to 0.08% is desirable.

  Ni is added as needed to suppress crevice corrosion and promote repassivation. Since this effect is manifested at 0.5% or more, the lower limit was made 0.5%. However, excessive addition hardens and deteriorates moldability, and stress corrosion cracking tends to occur, so the upper limit was made 1.0%. In consideration of raw material costs, 0.6 to 0.8% is desirable.

  Nb is added as necessary to suppress crevice corrosion and promote repassivation. Since this effect appears at 0.05% or more, the lower limit was made 0.05%. However, excessive addition hardens and deteriorates moldability, so the upper limit was made 0.50%. In consideration of the raw material cost, 0.1 to 0.3% is desirable.

  Cu is added as necessary to suppress crevice corrosion and promote repassivation. Since this effect appears from 0.5% or more, the lower limit was made 0.5%. However, since excessive addition hardens and deteriorates moldability, the upper limit was made 3.0%. In view of manufacturability, 0.6 to 1.5% is desirable.

  V is added as necessary to suppress crevice corrosion. Since this effect appears from 0.05% or more, the lower limit was made 0.05%. However, since excessive addition hardens and deteriorates moldability, the upper limit was made 1.0%. In consideration of the raw material cost, 0.1 to 0.5% is desirable.

  Mg may be added as a deoxidizing element, and is an element that contributes to improving the formability by refining the slab structure. Since this is expressed from 0.0002% or more, the lower limit was made 0.0002%. However, excessive addition leads to deterioration of weldability and corrosion resistance, so the upper limit was made 0.0030%. Considering the refining cost, 0.0003 to 0.0010% is desirable.

  Next, a manufacturing method will be described. The manufacturing method of the steel plate of this invention consists of each process of steelmaking-hot rolling-pickling-cold rolling-annealing. In steelmaking, a method in which the steel containing the above essential components and components added as necessary is subjected to furnace melting followed by secondary refining. The molten steel is made into a slab according to a known casting method (continuous casting). The slab is heated to a predetermined temperature and hot-rolled to a predetermined plate thickness by continuous rolling.

  In this invention, it pickles without performing hot-rolled sheet annealing, and uses for a cold-rolling process as a cold-rolling raw material. This is different from a normal manufacturing method (usually, hot-rolled sheet annealing is performed). A method for obtaining a sized recrystallized structure by performing hot rolling plate annealing is a general manufacturing method, but with this method, it is difficult to significantly reduce crystal grains before cold rolling. If the crystal grains before cold rolling are large, the grain boundary area decreases, and in particular, the crystal orientation that improves the r value does not develop in the product plate. FIG. 2 shows the relationship between the structure of the cold rolled material and the average r value × n value of the product plate. It can be seen that the formability is remarkably improved when cold rolling-annealing is performed using a material having a recrystallization grain size of 50 μm or less and a recrystallization rate of 5% or more and 90% or less. As described above, it is considered that the grain interfacial area of the cold-rolled material is increased, and crystal orientation advantageous for workability is easily generated during finish annealing. Further, the recrystallization rate may be 5% or more, and when it exceeds 90%, the coarsening of crystal grains starts. Therefore, the recrystallization rate is set to 90% or less.

The slab obtained by continuous casting is a hot rolled steel sheet having a predetermined thickness in the hot rolling process. Here, in order to obtain a steel plate having a high r value and n value even when the product thickness is stable and thick, it is necessary to perform hot rolling by the method described above. The slab heating temperature is such that if the heating temperature is too high, Ti carbon sulfide (Ti ₄ C ₂ S ₂ ) dissolves during heating, and recrystallization occurs due to an increase in solute carbon and reprecipitation during the hot rolling process. A phenomenon such as delay occurs. These phenomena suppress the development of the recrystallized texture of the product plate and deteriorate the workability. Further, the crystal grains are significantly enlarged, and coarse expanded grains are formed in the hot rolling process, so that the workability of the product plate is deteriorated. In addition, excessive temperature decrease causes surface flaws and causes corrosion resistance deterioration due to flaws from the ridges. For this reason, slab heating temperature is prescribed | regulated to 1100-1200 degreeC. Furthermore, in consideration of productivity reduction due to rolling roll baking, the slab heating temperature is preferably 1130 to 1170 ° C.

  In the hot rolling process, the rolling process is divided into a rough rolling process and a finishing rolling process including a plurality of stands, each of which is rolled in a plurality of passes. After rough rolling, finish rolling is performed at a high speed and the coil is wound into a coil. In the present invention, in order to obtain a fine recrystallized structure at the time of winding, the ratio between the rough rolling reduction ratio and the finish rolling reduction ratio and the finish rolling end temperature are specified. If the ratio between the rough rolling reduction ratio and the finishing rolling reduction ratio (total rolling reduction ratio / finishing rolling reduction ratio) is too high, the strain introduced in the finish rolling becomes small and recrystallization is not promoted during winding. On the other hand, if this is too low, stretched grains remain in the structure before finish rolling, and recrystallization does not occur even in finish rolling and winding. Furthermore, the finish rolling finish temperature and the winding temperature also affect the formation of the structure. If the finishing temperature and the winding temperature are too low, a fine recrystallized structure cannot be obtained. do not do. From this, the ratio of the total rolling reduction of rough rolling and the total rolling reduction of finish rolling (total rolling reduction of rough rolling / total rolling reduction of finish rolling) was set to 0.8 to 1.0. On the other hand, if the finishing temperature and the winding temperature are excessively high, coarse recrystallized grains are formed. On the other hand, if these are excessively low, recrystallization does not occur at the time of winding. The temperature is 900 ° C and the winding temperature is 650 to 850 ° C.

  Next, processes after hot rolling will be described. In the present invention, the steel sheet is pickled without being subjected to hot-rolled sheet annealing and is subjected to a cold rolling process. This is different from a normal manufacturing method (usually, hot-rolled sheet annealing is performed). And it discovered that workability improved notably by performing heat processing in the middle of cold rolling, and obtaining a fine recrystallized grain. From FIG. 3, in the intermediate annealing performed after the hot rolling and before the finish annealing, when the recrystallized grain size is 30 μm or less and the recrystallization rate is 50% or more and 100% or less, the r value × n value is 0. It turns out that it becomes 4 or more. The reason why the recrystallization rate does not have to be 100% is considered to be that if a fine structure of 50% or more is formed, this influence greatly contributes to workability and there is no adverse effect of other unrecrystallized structures. . It is still desirable if the entire plate thickness is a recrystallized structure with a fine structure. As a means for obtaining such a fine structure during cold rolling, heat treatment may be performed at 750 to 870 ° C. after hot rolling and before finish annealing. If it is less than 750 ° C., the recrystallization rate is less than 50%, and conversely, if the heat treatment is performed above 870 ° C., the recrystallization rate becomes 100%, but the crystal grain size increases, and the recrystallization texture from the grain boundary This is because development is less likely to occur. Furthermore, the temperature is preferably 800 to 850 ° C. in consideration of the plate-through property during production.

  Next, cold rolling conditions will be described. Cold rolling of a stainless steel plate is usually performed by reverse rolling with a Sendzimir rolling mill having a roll diameter of about 60 to 100 mm, or unidirectional rolling with a tandem rolling mill with a roll diameter of 400 mm or more. Both are rolled in a plurality of passes. In the present invention, in order to develop the <111> and <554> crystal orientations in the surface layer of the product plate, the large-diameter roll is cold-rolled with less shear strain introduced into the surface layer. The rolling reduction is 30% or more. Desirably, the rolling reduction is 50% or more from the viewpoint of productivity.

  Finally, finish annealing conditions will be described. From the viewpoint of improving the r value and the n value, it is desirable that the crystal grain size of the product plate is large. However, if the grain size is excessively large, the surface may be roughened during processing, or the ductility may be reduced. FIG. 4 shows the relationship between the crystal grain number of the product plate and the average r × n value. For the crystal grain size number, the crystal grain size at the center of the plate thickness was measured according to JISG0552. From this, in the process of providing intermediate annealing and cold rolling a large diameter roll, the average r × n value becomes 0.4 or more by setting the crystal grain size number to 8 or less. When the grain size number is less than 5, excessive skin roughness occurs during pressing, so the lower limit is set to 5 and the final annealing temperature is set to 900 to 1050 ° C. in order to adjust to this grain size number. Furthermore, the finish annealing temperature is preferably 950 to 1000 ° C. in consideration of the sheet-passability during production.

  Steel having the composition shown in Table 1 was melted and cast into a slab, and the slab was hot-rolled to form a hot-rolled coil having a thickness of 5 mm. Then, it pickled without performing hot rolling sheet annealing, and used for cold rolling. The product plate thickness was in a wide range of 0.6 to 1.6 mm, and a process of performing intermediate annealing in the middle was also included. In the finish annealing, a continuous annealing-pickling line was passed through to obtain a product plate.

  Tables 2 and 3 show the material properties and corrosion resistance of steel plates produced by various manufacturing methods. The material was measured by the method described above for r value and n value. As for the corrosion resistance, as an evaluation in a salt damage environment, a cyclic corrosion test in which a cycle of spraying → drying → dipping → drying is performed for 100 days continuously using a 5 mass% NaCl solution (50 ° C.), The corrosion depth was measured, and the case where the depth was 1/2 or less of the plate thickness was determined to be acceptable (◯), and the case where the depth was 1/2 or more was determined to be unacceptable (x). Further, as an evaluation in the fuel environment, the steel sheet was immersed in a solution containing 10% distilled water in deteriorated gasoline for 28 days, and then the corrosion state was observed. The case where corrosion did not occur in appearance and there was no significant change was judged as acceptable (◯), and the case where wrinkles occurred was regarded as unacceptable (x). Regarding press formability, a case where press molding could be performed into a predetermined shape was determined to be acceptable (O), and a case where significant constriction or cracking occurred was determined to be unacceptable (X). From Tables 2 and 3, it can be seen that in the examples of the present invention, any plate thickness can be pressed, and the corrosion resistance as a fuel component is excellent.

  Note that other conditions in the manufacturing process may be appropriately selected. For example, what is necessary is just to design slab thickness, hot rolling board thickness, etc. suitably. In cold rolling, roll roughness, roll diameter, rolling oil, number of rolling passes, rolling speed, rolling temperature, etc. may be appropriately selected. When intermediate annealing is performed in the middle of cold rolling, batch annealing or continuous annealing may be performed. Further, if necessary, the annealing atmosphere may be bright annealing performed in a non-oxidizing atmosphere such as hydrogen gas or nitrogen gas, or annealing in the air. Furthermore, the product plate may be lubricated to further improve press molding, and the type of lubricating film may be appropriately selected.

It is a figure which shows the relationship between the sum of the area ratio of {111} azimuth | direction of a product board + the area ratio of {554} azimuth | direction, and an average r value xn value. It is a figure which shows the relationship between the recrystallized grain size of a cold-rolling raw material, a recrystallization rate, and a product plate average r value xn value. It is a figure which shows the relationship between the recrystallized grain size of an intermediate annealing board, a recrystallization rate, and a product board average r value xn value. It is a figure which shows the relationship between the crystal grain size of a product board, and an average r value xn value.

Claims (2)

In mass%, C: 0.001 to 0.005%, Si: 0.01 to 0.20%, Mn: 0.01 to 0.20%, P: 0.01 to 0.03%, S : 0.0005-0.0100%, Cr: 16-25%, N: 0.001-0.020%, Mo: 0.5-2.0%, Ti: 0.05-0.25%, B: When hot-rolling a stainless steel slab containing 0.0002 to 0.0030% and the balance consisting of Fe and inevitable impurities, the slab heating temperature is set to 1100 to 1200 ° C., and the total rolling reduction of rough rolling Continuous rolling with a ratio of the total rolling reduction ratio of finish rolling (total rolling reduction ratio of rough rolling / total rolling reduction ratio of finishing rolling) of 0.8 to 1.0 is performed at a finish rolling finishing temperature of 700 to 900 ° C., 650 coiling at to 850 ° C., recrystallized grain size is not more 50μm or less, the recrystallization ratio of 5% or more 90% or less After obtaining that hot-rolled sheet,
The hot-rolled sheet annealing is omitted, and after performing cold rolling with a rolling reduction of 30% or more by unidirectional rolling using a roll having a diameter of 400 mm or more , heat treatment is performed at 750 to 870 ° C., and the recrystallized grain size is After obtaining an intermediate annealed plate having a recrystallization rate of 30% or less and a recrystallization ratio of 50% or more and 100% or less, and subsequently performing cold rolling , heat treatment is performed at 900 to 1050 ° C. in the finish annealing step, 8. A method for producing a ferritic stainless steel sheet excellent in workability , characterized by adjusting to 8 . The slab is further in mass%, Al: 0.005 to 0.10%, Ni: 0.5 to 1.0% , Cu: 0.5 to 3.0%, V: 0.05 to 1. .0%, Mg: 0.0002~0.0030% of one or manufacturing method of ferritic stainless steel sheet excellent in workability according to claim 1, characterized by containing two or more.

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