Ferritic stainless steel and method for producing same

Abstract

A ferritic stainless steel sheet according to one embodiment of the present invention may be a ferritic stainless steel sheet having excellent workability, the ferritic stainless steel sheet containing, in wt%, 0.0005-0.02% of C, 0.005-0.02% of N, 0.01-1.0% of Si, 0.01-1.0% of Mn, 0.001-0.05% of P, 13.0-20.0% of Cr, 0.05-0.5% of Ti, the remainder being Fe and unavoidable impurities, and having a {111} texture fraction of 50% or more in a region from the surface layer to 1 / 4 of the thickness.

Description

Technical Field

[0001] The present invention relates to a ferritic stainless steel, and more particularly to a ferritic stainless steel having excellent workability by controlling texture and a method for manufacturing the same. Background Art

[0002] Ferritic stainless steels are products used in various industrial fields such as home appliances, kitchen utensils, and automotive parts, and are required to have high workability that can cope with various processing methods. However, since ferritic stainless steels have a BCC crystal structure, they do not have TRIP like austenitic stainless steels, so there is a problem that the elongation rate is relatively reduced. On the other hand, ferritic stainless steels have the characteristic of forming a high {111} texture when appropriate manufacturing conditions are applied. Therefore, a high R value can be obtained by utilizing this, and it is advantageous for deep drawing processing. Therefore, ferritic stainless steels have a problem of lower elongation rate compared to austenitic stainless steels. Therefore, in various fields where ferritic stainless steels are applied, a technology is needed to enable ferritic stainless steels to cope with various processing methods. Summary of the Invention

[0003] (I) Technical Problem to be Solved

[0004] An object of the present invention for solving the above problems is to provide a ferritic stainless steel and a method for manufacturing the same, which control texture by optimizing the composition and manufacturing process of the steel, thereby improving workability.

[0005] The technical problems to be solved by the present invention are not limited to the above technical problems, and those skilled in the art can clearly understand other technical problems not described through the following description.

[0006] (II) Technical Solution

[0007] As a means for achieving the above object, a ferritic stainless steel sheet according to an example of the present invention may contain C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance being Fe and unavoidable impurities, by weight%, and is a ferritic stainless steel sheet having excellent workability with a fraction of {111} texture of 50% or more in the region from the surface layer to 1 / 4 of the thickness.

[0008] A ferritic stainless steel sheet according to an example of the present invention may be a ferritic stainless steel sheet having excellent workability with an R-bar value of 1.7 or more.

[0009] The manufacturing method of a ferritic stainless steel sheet according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, including the following steps: manufacturing a slab which, by weight %, contains: C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance being Fe and inevitable impurities; hot rolling the manufactured slab in a heating furnace at 1100 - 1300°C; performing primary rolling after hot rolling with a reduction ratio of 25 - 65%; performing hot rolling annealing at 900 - 1100°C after primary rolling; performing secondary rolling; and performing cold rolling annealing.

[0010] The manufacturing method of a ferritic stainless steel sheet according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, where the reduction ratio in the secondary rolling step is 40% or more.

[0011] The manufacturing method of a ferritic stainless steel sheet according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, where the cold rolling annealing step is performed at 850 - 1050°C.

[0012] The manufacturing method of a ferritic stainless steel sheet according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, where the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material after hot rolling annealing is 10% or more.

[0013] The manufacturing method of a ferritic stainless steel according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, where the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material after cold rolling annealing is 50% or more.

[0014] The manufacturing method of a ferritic stainless steel according to an example of the present invention may be a manufacturing method of a ferritic stainless steel sheet with excellent workability, where the R-bar value is 1.7 or more.

[0015] (III) Beneficial Effects

[0016] According to an embodiment of the present invention, a ferritic stainless steel and its manufacturing method can be provided, which form a {111} texture by including a primary rolling and a hot rolling annealing step, thereby having excellent workability. Description of the Drawings

[0017] Figure 1 A diagram showing the measurement of the {111} texture of the hot-rolled material of Invention Example 5 using electron backscatter diffraction (EBSD).

[0018] Figure 2 A diagram showing the {111} texture of the hot-rolled material of Comparative Example 2 measured by EBSD.

[0019] Figure 3 A diagram showing the fraction of the {111} texture of the hot-rolled material and the cold-rolled material.

[0020] Figure 4 A diagram showing the relationship between the reduction ratio of the first rolling and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material.

[0021] Figure 5 A diagram showing the relationship between the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness and R-bar. Detailed Description of the Invention

[0022] Hereinafter, preferred embodiments of the present invention will be described. However, the embodiments of the present invention can be deformed into various other forms, and the technical idea of the present invention is not limited to the embodiments described below. In addition, the embodiments of the present invention are provided to more completely describe the present invention to those skilled in the art.

[0023] The terms used in this application are only for explaining specific examples. Therefore, unless it is clearly stated as singular in the context, the singular expression includes the plural expression. In addition, it should be noted that the terms "comprising", "including" or "having" used in this application are used to clearly specify the existence of the features, steps, functions, components or combinations thereof described in the specification, rather than to pre-exclude the existence of other features, steps, functions, components or combinations thereof.

[0024] In addition, unless otherwise defined, all terms used in this specification should be regarded as having the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. Therefore, in this specification, unless otherwise clearly defined, specific terms should not be interpreted in an overly ideal or formal meaning.

[0025] Furthermore, with respect to "about", "substantially", etc. in this specification, when presenting the allowable errors of manufacturing and substances inherent in the mentioned meanings, they are used in the meaning of that value or close to that value, and are used to prevent unethical infringers from illegally using the mentioned accurate or absolute numerical values to help understand the disclosure of the present invention.

[0026] The ferritic stainless steel according to an example of the present invention may contain, by weight %, C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance being Fe and inevitable impurities, and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness is 50% or more.

[0027] The ferritic stainless steel according to an example of the present invention may be a ferritic stainless steel having an R-bar value of 1.7 or more.

[0028] The reasons for defining the composition ranges of the respective alloying elements are described below.

[0029] The content of C may be 0.0005 - 0.02 wt%.

[0030] When C is less than 0.0005%, the refining cost for producing high-purity products increases. When C exceeds 0.02%, the corrosion resistance and formability may deteriorate. Considering this, the content of C may be 0.0005 - 0.02 wt%.

[0031] The content of N may be 0.005 - 0.02 wt%.

[0032] When N is less than 0.005%, the crystallinity of TiN is low and the equiaxed crystallinity of the slab decreases. When N exceeds 0.02%, the corrosion resistance and formability may deteriorate. Considering this, the content of N may be 0.005 - 0.02%.

[0033] The content of Si may be 0.01 - 1.0 wt%.

[0034] When Si is less than 0.01%, the refining cost increases. When Si exceeds 1.0%, the impurity content increases and the formability may deteriorate. Considering this, the content of Si may be 0.01 - 1.0%.

[0035] The content of Mn may be 0.01 - 1.0 wt%.

[0036] When Mn is less than 0.01%, the refining cost increases. When Mn exceeds 1.0%, the impurity content increases and the formability may deteriorate. Considering this, the content of Mn may be 0.01 - 1.0%.

[0037] The content of P may be 0.001 - 0.05 wt%.

[0038] When P is less than 0.001%, the refining price increases. When P exceeds 0.05%, the impurity content increases, and the formability may deteriorate. Considering this, the content of P can be 0.001 - 0.05%.

[0039] The content of Cr can be 13.0 - 20.0 wt%.

[0040] When Cr is less than 13.0%, the corrosion resistance deteriorates. When Cr exceeds 20.0%, the formability may deteriorate. Considering this, the content of Cr can be 13.0 - 20.0%.

[0041] The content of Ti can be 0.05 - 0.5 wt%.

[0042] When Ti is less than 0.05%, recrystallization during hot rolling is insufficient. When Ti exceeds 0.5%, a large amount of steel-making inclusions may be generated. Considering this, the content of Ti can be 0.05 - 0.5%.

[0043] The content of Ti / (C + N) can be 1.25% or more.

[0044] When Ti / (C + N) is less than 1.25%, recrystallization during hot rolling is insufficient, and the corrosion resistance and formability may deteriorate. When the content of Ti / (C + N) is 1.25% or more, before hot rolling annealing, the pre-rolling mill (Pre-Rolling Mill), that is, before hot rolling annealing, the deformation energy of the hot-rolled material can be accumulated by applying pressure, thereby realizing recrystallization, and thus the elongation and drawability in the final product can be ensured.

[0045] The remaining component is iron (Fe). However, during the normal manufacturing process, unwanted impurities will inevitably be mixed in from raw materials or the surrounding environment, so these impurities cannot be excluded. These impurities are well known to those skilled in the normal manufacturing process, so all of their contents are not particularly mentioned in this specification.

[0046] The manufacturing method of the ferritic stainless steel of the present invention can hot-roll the obtained slab - perform primary rolling - perform hot rolling annealing, and can further perform secondary rolling - cold rolling annealing steps.

[0047] The method for manufacturing a ferritic stainless steel according to an example of the present invention may include the following steps: manufacturing a slab which, by weight %, contains: C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance of Fe and inevitable impurities; hot rolling the manufactured slab in a heating furnace at 1100 - 1300°C; performing primary rolling with a reduction ratio of 25 - 65% after hot rolling; performing hot rolling annealing at 900 - 1100°C after primary rolling; performing secondary rolling; and performing cold rolling annealing.

[0048] The alloy composition of the method for manufacturing a ferritic stainless steel according to an example of the present invention may be the same as that of the ferritic stainless steel according to an example of the present invention described above.

[0049] The method for manufacturing a ferritic stainless steel of the present invention may be the step of hot rolling the slab in the hot rolling step in a heating furnace at 1100 - 1300°C.

[0050] When the temperature of the hot rolling step is lower than 1100°C, it may be difficult to perform bundling and conveying due to hot rolling defects. When the temperature of the hot rolling step exceeds 1300°C, it may be difficult to bend and convey the slab. Considering this, the hot rolling step may be performed at a temperature of 1100 - 1300°C.

[0051] The primary rolling step of the method for manufacturing a ferritic stainless steel of the present invention may be the step of performing rolling with a reduction ratio of 25 - 65%.

[0052] When the reduction ratio of the primary rolling is less than 25%, the deformation energy is low and recrystallization is insufficient, and it may be difficult to ensure that the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness is 10% or more. When the reduction ratio of the primary rolling exceeds 65%, the reduction ratio of the secondary rolling is insufficient, and it may be difficult to ensure that the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness in the final cold-rolled material is 50% or more. When the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness cannot be ensured, the R-bar value may not be ensured. Considering this, the reduction ratio of the primary rolling may be set to 25 - 65%.

[0053] The hot rolling annealing step of the method for manufacturing a ferritic stainless steel of the present invention may be the step of performing hot rolling annealing at 900 - 1100°C.

[0054] When the temperature of the hot rolling annealing step is lower than 900 °C, recrystallization does not occur and texture may not be formed. When the temperature of the hot rolling annealing step exceeds 1100 °C, the grains become coarser and plate fracture may occur. Considering this, the hot rolling annealing step can be carried out at a temperature of 900 - 1100 °C.

[0055] By including a rolling step before hot rolling annealing, the deformation energy of the hot rolled material can be accumulated and recrystallization can be carried out by hot rolling annealing.

[0056] In the method for manufacturing ferritic stainless steel of the present invention, after the hot rolling step, the first rolling step, and the hot rolling annealing step, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot rolled material after hot rolling annealing can be 10% or more.

[0057] The second rolling step of the method for manufacturing ferritic stainless steel of the present invention can be a step of rolling with a reduction rate of 40% or more.

[0058] When the reduction rate of the second rolling is 40% or more, recrystallization occurs and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the final cold rolled material can be ensured to be 50% or more. When ensuring the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness, the R-bar value can be ensured. Considering this, the reduction rate of the second rolling can be set to 40% or more.

[0059] The cold rolling annealing step of the method for manufacturing ferritic stainless steel of the present invention can be a step of carrying out cold rolling annealing at 850 - 1050 °C.

[0060] When the temperature of the cold rolling annealing step is 850 °C or higher, recrystallization occurs and texture may be formed. When the temperature of the cold rolling annealing step is 1050 °C or lower, grain coarsening and plate fracture can be prevented. Considering this, the cold rolling annealing step can be carried out at a temperature of 850 - 1050 °C.

[0061] After the second rolling step and the cold rolling annealing step of the method for manufacturing ferritic stainless steel of the present invention, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold rolled material after cold rolling annealing can be 50% or more.

[0062] In the method for manufacturing ferritic stainless steel of the present invention, for the ferritic stainless steel that is first rolled, then second rolled, and then cold rolled and annealed, by ensuring that the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness is 50% or more, the R-bar value can be ensured to be 1.7 or more.

[0063] Among them, R-bar is composed of (R0 + R 90 +2 R 45 ) / 4. The value calculated can be 1.7 or more. R0 is the R value in the 0° direction with respect to the rolling direction of the test piece, and R 45 is the R value in the 45° direction, and R 90 is the R value in the 90° direction. The R value is the width strain / thickness strain. The higher the R-bar value, the more favorable it is for elongation and deep drawing processing.

[0064] Hereinafter, the present invention will be described in more detail by way of examples. However, the description of these examples is only for illustrating the implementation of the present invention, and the present invention is not limited by the description of these examples. This is because the scope of the rights of the present invention is determined by the content described in the claims and the content reasonably deduced therefrom.

[0065] {Examples}

[0066] Prepare the alloy composition according to Table 1 below.

[0067] [Table 1]

[0068]

[0069] Table 2 below shows whether the slab having the alloy composition of Table 1 is subjected to one-pass rolling, the fraction of the {111} texture and the R-bar value in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled and cold-rolled materials according to the reduction ratio. While changing whether to perform one-pass rolling and controlling the reduction ratio as shown in Table 1 below, the implementation is carried out. The reheating temperature of the hot-rolled slab is 1200 °C, the change in the reduction ratio of one-pass rolling is as shown in Table 1 below, the hot-rolled annealing temperature is 1000 °C, the reduction ratio of two-pass rolling is 40%, and the cold-rolled annealing temperature is 950 °C.

[0070] The fraction (%) of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material refers to the measured value of the fraction of the {111} texture from the surface layer to 1 / 4 of the thickness of the hot-rolled material annealed by hot rolling measured by the EBSD system installed in the scanning electron microscope.

[0071] The fraction (%) of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material refers to the measured value of the fraction of the {111} texture from the surface layer to 1 / 4 of the thickness of the cold-rolled material annealed by cold rolling measured by the EBSD system installed in the scanning electron microscope.

[0072] [Table 2]

[0073]

[0074] Referring to Table 1 and Table 2, in Invention Examples 1 to 3 where the steel grade A with an alloy composition satisfying the scope of the present invention is subjected to one-pass rolling with a reduction ratio of 30%, Invention Examples 4 to 6 where the steel grade B is subjected to one-pass rolling with a reduction ratio of 40%, and Invention Examples 7 to 9 where the steel grade C is subjected to one-pass rolling with a reduction ratio of 60%, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is 10% or more, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is 50% or more, and it satisfies the scope of the present invention. Therefore, the R-bar value is 1.7 or more and satisfies the scope of the present invention. Thus, it can be confirmed that for the slab with an alloy composition satisfying the present invention, when it is subjected to one-pass rolling with a reduction ratio of 25 - 65%, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is 10% or more, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is 50% or more, and it satisfies the control range of the present invention, and as a result, an R-bar value of 1.7 or more can be ensured. Comparative Examples 1 to 3 correspond to the cases where the steel grade A, steel grade B, and steel grade C satisfying the scope of the present invention are not subjected to one-pass rolling at all. In Comparative Examples 1 to 3, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is less than 10%, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, and it cannot satisfy the scope of the present invention. Therefore, the R-bar value is less than 1.7 and cannot satisfy the scope of the present invention.

[0075] Thus, it can be confirmed that even if the alloy composition is satisfied, when no one-pass rolling is performed at all, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is less than 10%, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, it cannot satisfy the control range of the present invention, and as a result, an R-bar value of 1.7 or more cannot be ensured.

[0076] Comparative Examples 4 to 6 correspond to the cases where the steel grade A, steel grade B, and steel grade C satisfying the scope of the present invention are subjected to one-pass rolling with a reduction ratio of 20%. In Comparative Examples 4 to 6, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is less than 10%, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, and it cannot satisfy the scope of the present invention. Therefore, the R-bar value is less than 1.7 and cannot satisfy the scope of the present invention.

[0077] Accordingly, it can be confirmed that even when the alloy composition is satisfied, when the rolling reduction rate is less than 25% in a single rolling pass, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is less than 10%, and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, which cannot meet the control range of the present invention. As a result, it is impossible to ensure that the R-bar value is 1.7 or more.

[0078] Comparative Examples 7 to 9 correspond to the case where the steel grades A, B, and C that satisfy the scope of the present invention are rolled in a single pass with a rolling reduction rate of 70%. In Comparative Examples 7 to 9, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is 10% or more, but the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, and the scope of the present invention cannot be satisfied. Therefore, the R-bar value is less than 1.7, and the scope of the present invention cannot be satisfied.

[0079] Accordingly, it can be confirmed that even when the alloy composition is satisfied, when the rolling reduction rate is more than 65% in a single rolling pass, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is 10% or more, but the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is less than 50%, which cannot meet the control range of the present invention. As a result, it can be not ensured that the R-bar value is 1.7 or more.

[0080] The manufacturing method of a ferritic stainless steel sheet excellent in workability according to an example of the present invention will be described with reference to the drawings.

[0081] Figure 1 It is a diagram of the {111} texture showing the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material of Invention Example 5 measured by EBSD.

[0082] Figure 2 It is a diagram of the {111} texture showing the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material of Comparative Example 2 measured by EBSD.

[0083] In Invention Example 5 and Comparative Example 2, a steel grade B slab that satisfies the alloy composition of the present invention is used. Invention Example 5 is the case of rolling in a single pass with a rolling reduction rate of 40%, and Comparative Example 2 is the case of not performing rolling in a single pass at all.

[0084] In Figure 1 and Figure 2 The portion with a high fraction of the {111} texture is shown in a darker color. When measured by EBSD, the higher the fraction of the {111} texture, the lower the brightness, and the lower the fraction of the {111} texture, the higher the brightness.

[0085] See Figure 1 and Figure 2 , it can be confirmed that, compared with Comparative Example 2, the fraction of the {111} texture in Invention Example 5 with one-pass rolling is higher, resulting in lower brightness.

[0086] At this time, high brightness indicates a color close to a bright color (e.g., white), and low brightness indicates a color close to a dark color (e.g., black).

[0087] This indicates that when performing one-pass rolling, due to the shear deformation during the hot rolling process, the fraction of the {111} texture in the hot-rolled material increases.

[0088] Figure 3 It is a graph showing the fraction of the {111} texture in the hot-rolled material and the cold-rolled material. It can be confirmed that when the fraction of the {111} texture in the hot-rolled material is high, the fraction of the {111} texture in the cold-rolled material is high.

[0089] Figure 4 It is a graph showing the relationship between the reduction ratio of one-pass rolling and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material.

[0090] See Figure 4 , it can be confirmed that when performing one-pass rolling with a reduction ratio of 25 - 65%, the fraction of the {111} texture in the cold-rolled material is ensured to be 50% or more.

[0091] See Figures 1 to 4 , it can be confirmed that when performing one-pass rolling, the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material can be ensured to be 10% or more and at a high level, and the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material can be ensured to be 50% or more.

[0092] Figure 5 It is a graph showing the relationship between the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material and R-bar.

[0093] See Figure 5 , it can be confirmed that when the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is 50% or more, the R-bar value is ensured to be 1.7 or more.

[0094] See Figures 1 to 5, it can be confirmed that when performing one rolling pass, it is possible to ensure that the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material is 10% or more and at a high level, ensure that the fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material is 50% or more, and it is possible to ensure that the R-bar value is 1.7 or more.

Claims

1. A ferritic stainless steel sheet with excellent workability, by weight %, the ferritic stainless steel sheet contains: C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance Fe and unavoidable impurities, The fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness is 50% or more.

2. The ferritic stainless steel sheet excellent in workability according to claim 1, wherein, The R-bar value is 1.7 or more.

3. A method for manufacturing a ferritic stainless steel sheet with excellent workability, which includes the following steps: Manufacture a slab, by weight %, the slab contains: C: 0.0005 - 0.02%, N: 0.005 - 0.02%, Si: 0.01 - 1.0%, Mn: 0.01 - 1.0%, P: 0.001 - 0.05%, Cr: 13.0 - 20.0%, Ti: 0.05 - 0.5%, the balance Fe and unavoidable impurities; Hot-roll the manufactured slab in a heating furnace at 1100 - 1300 °C; After hot rolling, perform primary rolling with a reduction ratio of 25 - 65%; After primary rolling, perform hot rolling annealing at 900 - 1100 °C; Perform secondary rolling; and Perform cold rolling annealing.

4. The manufacturing method of the ferritic stainless steel sheet excellent in workability according to claim 3, wherein, The reduction ratio of the secondary rolling step is 40% or more.

5. The method for manufacturing a ferritic stainless steel sheet having excellent workability according to claim 3, wherein, The cold rolling annealing step is performed at 850 - 1050 °C.

6. The manufacturing method of the ferritic stainless steel sheet excellent in processability according to claim 3, wherein, The fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the hot-rolled material after the hot rolling annealing is 10% or more.

7. The method for manufacturing a ferritic stainless steel sheet with excellent workability according to claim 3, wherein, The fraction of the {111} texture in the region from the surface layer to 1 / 4 of the thickness of the cold-rolled material after the cold rolling annealing is 50% or more.

8. The manufacturing method of a ferritic stainless steel sheet with excellent workability according to claim 3, wherein, The R-bar value is 1.7 or more.

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