US20150020933A1 - Heat-resistant cold rolled ferritic stainless steel sheet, hot rolled ferritic stainless steel sheet for cold rolling raw material, and methods for producing same - Google Patents

Heat-resistant cold rolled ferritic stainless steel sheet, hot rolled ferritic stainless steel sheet for cold rolling raw material, and methods for producing same Download PDF

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US20150020933A1
US20150020933A1 US14/383,434 US201314383434A US2015020933A1 US 20150020933 A1 US20150020933 A1 US 20150020933A1 US 201314383434 A US201314383434 A US 201314383434A US 2015020933 A1 US2015020933 A1 US 2015020933A1
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sheet
steel sheet
hot rolled
stainless steel
temperature
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Junichi Hamada
Yuji Koyama
Yoshiharu Inoue
Tadashi Komori
Fumio Fudanoki
Toshio Tanoue
Naoto Ono
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Nippon Steel Stainless Steel Corp
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Nippon Steel and Sumikin Stainless Steel Corp
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/002—Heat treatment of ferrous alloys containing Cr
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/02—Modifying the physical properties of iron or steel by deformation by cold working
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0236—Cold rolling
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
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    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
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    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
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    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
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    • C22C38/008—Ferrous alloys, e.g. steel alloys containing tin
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    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
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    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
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    • C22C—ALLOYS
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    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • C—CHEMISTRY; METALLURGY
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
    • C—CHEMISTRY; METALLURGY
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C—CHEMISTRY; METALLURGY
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    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
    • C—CHEMISTRY; METALLURGY
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    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2201/00—Treatment for obtaining particular effects
    • C21D2201/05—Grain orientation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Definitions

  • the present invention relates to a heat-resistant cold rolled ferritic stainless steel sheet which is appropriate for use especially in exhaust system members of vehicles and the like requiring a high temperature strength and oxidation resistance and has excellent workability, a hot rolled ferritic stainless steel sheet for a material for cold rolling (cold rolling raw material), and methods for producing the same.
  • Heat-resistant steel containing Cr is used in exhaust system members such as exhaust manifolds and mufflers of vehicles, since the members require a high temperature strength and oxidation resistance. Since these exhaust system members may be manufactured through press working from a steel sheet or through various formings after pipe working of a steel sheet, cold rolled steel sheets as a raw material are required to have formability.
  • the operating temperature of the members is also increased every year, and it is necessary to increase the high temperature strength and the like by increasing the added amounts of alloys such as Cr, Mo, and Nb.
  • alloys such as Cr, Mo, and Nb.
  • the amounts of added elements are increased, the workability of a raw material steel sheet is decreased in a simple manufacturing method, and thus press forming may not be performed on members having a complicated shape.
  • Patent Document 1 discloses component adjustment to improve workability of conventional heat-resistant ferritic stainless steel sheets, but with this, a problem occurs such as press cracking in thick materials having a relatively low cold rolling reduction ratio.
  • Patent Document 2 in order to improve the r-value, the most appropriate annealing temperature of a hot rolled sheet is specified based on a relationship of an annealing temperature of a hot rolled sheet to a hot finish rolling start temperature, a hot finish rolling end temperature, and an Nb content.
  • sufficient workability may not be obtained according to influences of other elements (C, N, Cr, Mo, and the like) involved especially in Nb-based precipitates.
  • Patent Document 3 discloses a method of subjecting a hot rolled sheet to aging for 1 hour or longer, but in this case, there is a disadvantage in that the industrial manufacturing efficiency is greatly reduced.
  • Patent Document 4 discloses a technology for obtaining a Cr-containing heat-resistant steel sheet having a high r-value in which conditions for hot rolling and annealing of a hot rolled sheet are specified to control the crystal orientation of a center layer in a sheet thickness direction.
  • the r-value is not determined only with the crystal orientation of the center layer in a sheet thickness direction of the product, sufficient workability may not be obtained.
  • a heating temperature of a slab in hot rolling is in a range of 1,000° C. to 1,150° C. which is low, there is a problem such as surface scratches.
  • Patent Document 5 discloses a technology of specifying the crystal orientation in a region from an outermost layer to a depth of one quarter of a sheet thickness in a ferritic stainless steel sheet for an exhaust component having excellent workability. This technique increases the r-value and total elongation in a direction at an angle of 45° with respect to a rolling direction, and the technique is characterized in that annealing of a hot rolled sheet is omitted in the manufacturing method.
  • Patent Document 1 Japanese Unexamined Patent Application, First Publication No. H9-279312
  • Patent Document 2 Japanese Unexamined Patent Application, First Publication No. 2002-30346
  • Patent Document 3 Japanese Unexamined Patent Application, First Publication No. H8-199235
  • Patent Document 4 PCT International Publication No. WO2004/53171
  • Patent Document 5 Japanese Unexamined Patent Application, First Publication No. 2006-233278
  • An object of the invention is to solve problems of known technologies and to provide a heat-resistant cold rolled ferritic stainless steel sheet which has excellent workability, a hot rolled ferritic stainless steel sheet for a material for cold rolling, and methods for producing the same.
  • the inventors of the invention have conducted an intensive study on steel composition and on structures and precipitates in manufacturing processes, i.e., a hot rolling process and a cold rolling process with regard to an improvement in workability of a heat-resistant cold rolled ferritic stainless steel sheet, especially in r-value.
  • a heat-resistant cold rolled ferritic stainless steel sheet containing, in terms of mass %, 0.02% or less of C, 0.1% to 1.0% of Si, greater than 0.6% to 1.5% of Mn, 0.01% to 0.05% of P, 0.0001% to 0.0100% of S, 13.0% to 20.0% of Cr, 0.1% to 3.0% of Mo, 0.005% to 0.20% of Ti, 0.30% to 1.0% of Nb, 0.0002% to 0.0050% of B, 0.005% to 0.50% of Al, and 0.02% or less of N, with the balance being Fe and inevitable impurities, wherein when a sheet thickness is represented by t, ⁇ 111 ⁇ -oriented grains are present at an area ratio of 20% or greater in a region from a surface layer to t/4, ⁇ 111 ⁇ -oriented grains are present at an area ratio of 40% or greater in a region from t/4 to t/2, and ⁇ 011 ⁇ -oriented grains are present at an area ratio of 15% or
  • the cold rolled stainless steel sheet has excellent workability.
  • the region from the surface layer to t/4 is a region ranging from the surface of the steel sheet to a depth of t/4
  • the region from t/4 to t/2 is a region ranging from a depth of t/4 to the center in the sheet thickness direction.
  • the heat-resistant cold rolled ferritic stainless steel sheet according to the first aspect which further contains, in terms of mass %, one or more selected from 0.4% to 2.0% of Cu, 0.1% to 2.0% of Ni, 0.1% to 3.0% of W, 0.05% to 0.30% of Zr, 0.05% to 0.50% of Sn, 0.05% to 0.50% of Co, and 0.0002% to 0.0100% of Mg.
  • a hot rolled ferritic stainless steel sheet for a material for cold rolling for manufacturing the heat-resistant cold rolled ferritic stainless steel sheet according to the first or second aspect wherein when a sheet thickness is represented by t′, a microstructure in a region from t′/2 to t′/4 is a non-recrystallized microstructure.
  • the region from t′/2 to t′/4 is a region ranging from a depth of t′/4 to the center in the sheet thickness direction.
  • the hot rolled ferritic stainless steel sheet according to the third aspect has substantially the same composition as the heat-resistant cold rolled ferritic stainless steel sheet according to the first or second aspect.
  • a method for producing the hot rolled ferritic steel sheet for a material for cold rolling including: performing hot rolling under conditions where a heating temperature of a slab (semi-finished product) is set to be in a range of 1200° C. to 1300° C. and a finishing temperature is set to be in a range of 800° C. to 950° C. so as to form a hot rolled sheet; coiling the hot rolled sheet at a coiling temperature of 500° C. or lower; and then annealing the hot rolled sheet at a temperature of 925° C. to 1000° C.
  • the slab which is a raw material of the steel sheet a slab having substantially the same composition as the steel sheet according to the first or second aspect is used.
  • a method for producing the heat-resistant cold rolled ferritic stainless steel sheet according to the first or second aspect including: subjecting a hot rolled ferritic steel sheet for a material for cold rolling in which when a sheet thickness is represented by t′, a microstructure in a region from t′/2 to t′/4 is a non-recrystallized microstructure to cold rolling at a rolling reduction ratio of 60% or greater so as to form a cold rolled sheet; and then annealing the cold rolled sheet at a temperature of 1000° C. to 1100° C.
  • the hot rolled steel sheet which is a raw material of the cold rolled steel sheet
  • a steel sheet having substantially the same composition as the cold rolled steel sheet according to the first or second aspect is used.
  • the method for producing the heat-resistant cold rolled ferritic stainless steel sheet may include a process of manufacturing the hot rolled ferritic steel sheet for a material for cold rolling. That is, according to a sixth aspect of the invention, there is provided the method for producing the heat-resistant cold rolled ferritic stainless steel sheet according to the fifth aspect, including: performing hot rolling under conditions where a heating temperature of a slab is set to be in a range of 1200° C. to 1300° C. and a finishing temperature is set to be in a range of 800° C. to 950° C. so as to form a hot rolled sheet; coiling the hot rolled sheet at a coiling temperature of 500° C.
  • the slab which is a raw material of the steel sheet a slab having substantially the same composition as the steel sheet according to the first or second aspect is used.
  • a heat-resistant cold rolled ferritic stainless steel sheet it is possible to secure a high r-value by specifying a component composition of steel together with optimizing conditions of a hot rolling process and a cold rolling process, and controlling microstructures of respective regions in a sheet thickness direction.
  • the steel microstructure before the cold rolling process is set to be a non-recrystallized microstructure in which recrystallization is suppressed together with a ⁇ 111 ⁇ texture allowed to remain, a lot of crystal grains having a ⁇ 111 ⁇ direction which effectively act for an improvement in the r-value can be generated in the subsequent cold rolling and annealing processes; and thereby, a recrystallized microstructure which is advantageous for workability can be obtained.
  • FIG. 1 is a graph showing a relationship between an area ratio of ⁇ 111 ⁇ -oriented grains in a region from a surface layer to t/4 (t: sheet thickness) and an average r-value in a cold rolled ferritic stainless steel sheet of an embodiment.
  • FIG. 2 is a graph showing a relationship between an area ratio of ⁇ 111 ⁇ -oriented grains in a region from t/4 to t/2 (t: sheet thickness) and an average r-value in the cold rolled ferritic stainless steel sheet of the embodiment.
  • FIG. 3 is a graph showing a relationship between an area ratio of ⁇ 011 ⁇ -oriented grains in the entire region in a sheet thickness direction and an average r-value in the cold rolled ferritic stainless steel sheet of the embodiment.
  • FIG. 4 is a graph showing a relationship between an annealing temperature T1of a hot rolled sheet and an average r-value of a cold rolled ferritic stainless steel sheet (product sheet) of the embodiment.
  • a cold rolled ferritic stainless steel sheet of this embodiment contains, in terms of mass %, 0.02% or less of C, 0.1% to 1.0% of Si, greater than 0.6% to 1.5% of Mn, 0.01% to 0.05% of P, 0.0001% to 0.0100% of S, 13.0% to 20.0% of Cr, 0.1% to 3.0% of Mo, 0.005% to 0.20% of Ti, 0.30% to 1.0% of Nb, 0.0002% to 0.0050% of B, 0.005% to 0.50% of Al, and 0.02% or less of N, with the balance being Fe and inevitable impurities.
  • crystal grains having a ⁇ 111 ⁇ orientation are present at an area ratio of 20% or greater in a region from a surface layer to t/4, crystal grains having a ⁇ 111 ⁇ orientation are present at an area ratio of 40% or greater in a region from t/4 to t/2, and crystal grains having a ⁇ 011 ⁇ orientation are present at an area ratio of 15% or less in the entire region in a thickness direction.
  • the region from the surface layer to t/4 is a region ranging from the surface of the steel sheet to a depth of t/4
  • the region from t/4 to t/2 is a region ranging from a depth of t/4 to the center in the sheet thickness direction.
  • the crystal grains having a ⁇ 111 ⁇ orientation are crystal grains in which the sheet surface (the surface of the steel sheet) and the ⁇ 111 ⁇ plane are in parallel.
  • the crystal grains having a ⁇ 011 ⁇ orientation are crystal grains in which the sheet surface and the ⁇ 011 ⁇ plane are in parallel.
  • the area ratio can be indicated as an area ratio of ⁇ 111 ⁇ -oriented grains and as an area ratio of ⁇ 011 ⁇ -oriented grains in a plane which is perpendicular to the sheet surface and in parallel to a rolling direction.
  • the area ratio can be obtained by, for example, measuring a crystal orientation distribution in a cross-section of the steel sheet through an electron backscatter diffraction image method.
  • the upper limit is set to 0.02%.
  • the lower limit is preferably set to 0.001%.
  • the content of C is desirably in a range of 0.002% to 0.01% in consideration of manufacturing costs and corrosion resistance.
  • Si may be added as a deoxidation element and is an element which improves oxidation resistance and high temperature strength of steel.
  • Si is an element which promotes precipitation of Laves phases. Accordingly, the addition thereof in an amount of 0.1% or greater causes precipitation of coarse Laves phases during annealing of a hot rolled sheet, and contributes to the development of ⁇ 111 ⁇ -oriented grains and the suppression of ⁇ 011 ⁇ -oriented grains during annealing of a cold rolled sheet and an improvement in the r-value. Since an excessive addition reduces room temperature ductility and thus deteriorates workability, the upper limit is set to 1.0%.
  • the content of Si is desirably in a range of 0.2% to 0.5% in consideration of material quality and oxidation characteristics.
  • Mn forms MnCr 2 O 4 and MnO at a high temperature, and Mn improves scale adhesion. Since these effects are exhibited in the case where the amount of Mn is greater than 0.6%, the lower limit is set to be in a range of greater than 0.6%. Meanwhile, since a mass gain due to oxidation is increased, breakaway (abnormal oxidation) easily occurs in the case where Mn is added in an amount of greater than 1.5%. In exhaust gas components such as exhaust manifolds, in the case where scale peeling and breakaway occur, problems may occur in subsequent components such as a catalyst, a muffler, or reliability of a structure may be reduced due to a reduction in the sheet thickness. Furthermore, the content of Mn is desirably in a range of 0.7% to 1.1% in consideration of workability and manufacturability.
  • P is a solid solution strengthening element as is the case with Si, but P is an element which is harmful to corrosion resistance and toughness of steel. Accordingly, the smaller the content thereof is, the better it is in view of material quality. Thus, the upper limit is set to 0.05%. However, since an excessive reduction leads to an increase in refining costs, the lower limit is set to 0.01%.
  • the content of P is desirably in a range of 0.015% to 0.025% in consideration of manufacturing costs and oxidation resistance.
  • the upper limit is set to 0.0100%.
  • an excessive addition of S leads to generation of a compound with Ti, and thus recrystallization and grain growth of the hot rolled and annealed sheet are promoted.
  • non-recrystallized microstructure cannot be secured in the hot rolled steel sheet; and as a result, the r-value is deteriorated.
  • the lower limit is set to 0.0001%.
  • the content of S is desirably in a range of 0.0010% to 0.0050% in consideration of manufacturing costs and corrosion resistance.
  • the amount of Cr is set to be in the range of 13.0% to 20.0%.
  • the content of Cr is desirably in a range of 15.0% to 19.0% from the viewpoint of costs and corrosion resistance.
  • Mo improves corrosion resistance, and also leads to an improvement in high temperature strength and thermal fatigue characteristics of steel by a solid-solubilized Mo. Since these effects are exhibited in the case where the amount of Mo is in a range of 0.1% or greater, the lower limit is set to 0.1%. However, an excessive addition leads to a deterioration in toughness and a reduction in elongation. In addition, too many Laves phases are generated in the annealing process of a hot rolled sheet and in the annealing process of a cold rolled sheet, and thus ⁇ 011 ⁇ -oriented grains are easily generated and the r-value is reduced. Moreover, since oxidation resistance deteriorates in the case where Mo is added in an amount greater than 3.0%, the upper limit is set to 3.0%.
  • the content of Mo is desirably in a range of 1.5% to 1.8% in consideration of high temperature characteristics after exposure to a high temperature for a long period of time, especially, a high temperature strength, thermal fatigue characteristics, and high-temperature and high-cycle fatigue characteristics and in consideration of manufacturing costs and manufacturability.
  • Ti is an element which is added to further improve corrosion resistance, intergranular corrosion resistance, and deep drawability by bonding to C, N, and S. Particularly, since development of ⁇ 111 ⁇ crystal orientation which improves the r-value is exhibited in the case where Ti is added in an amount of 0.005% or greater, the lower limit is set to 0.005%. Since toughness and secondary workability deteriorate in the case where Ti is added in an amount of 0.20% or greater, the upper limit is set to 0.2%.
  • the content of Ti is desirably in a range of 0.06% to 0.15% in consideration of manufacturing costs, surface scratches, and scale spallability.
  • Nb improves a high temperature strength and high temperature fatigue characteristics due to solid solution strengthening and precipitation strengthening, and thus Nb is an essential element.
  • Nb fixes C and N as carbonitrides to develop a recrystallization texture of the cold rolled steel sheet (product sheet), Nb forms an intermetallic compound of Fe and Nb, which is called as Laves phase, Nb has an influence on the formation of the recrystallization texture according to a volume fraction and a size thereof, and thus Nb contributes to an improvement in the r-value.
  • the lower limit is set to 0.30%. Since an excessive addition of Nb leads to hardening, and thus this results in a reduction in room temperature ductility, the upper limit is set to 1.0%.
  • the content of Nb is desirably in a range of 0.40% to 0.60% in consideration of costs and manufacturability.
  • N deteriorates workability and oxidation resistance of steel as is the case with C.
  • the content of N is desirably in a range of 0.005% to 0.015% in consideration of costs.
  • B is an element which improves secondary workability during press working of the product and improves a high temperature strength in an intermediate temperature range. Since these effects are exhibited in the case where the addition amount of B is in a range of 0.0002% or greater, the lower limit is set to 0.0002%. In the case where B is added in an amount greater than 0.0050%, a B compound such as Cr 2 B and the like is generated, intergranular corrosion and fatigue characteristics are deteriorated, ⁇ 011 ⁇ -oriented grains are increased, and thus the r-value is reduced. Therefore, the upper limit is set to 0.0050%. Furthermore, the content of B is desirably in a range of 0.0003% to 0.0020% in consideration of weldability and manufacturability.
  • Al may be added as a deoxidation element and Al improves a high temperature strength and oxidation resistance of steel. Since the actions thereof are exhibited in the case where the amount of Al is in a range of 0.005% or greater, the lower limit is set to 0.005%. In the case where Al is added in an amount greater than 0.50%, elongation of stainless steel is reduced, weldability and surface quality are deteriorated, generation of ⁇ 011 ⁇ -oriented grains is promoted by an Al oxide, and the r-value of the steel sheet is reduced, and thus the upper limit is set to 0.50%.
  • the content of Al is desirably in a range of 0.01% to 0.15% in consideration of refining costs.
  • the steel sheet preferably further contains, in terms of mass %, one or more of 0.4% to 2.0% of Cu, 0.1% to 2.0% of Ni, 0.1% to 3.0% of W, 0.05% to 0.30% of Zr, 0.05% to 0.50% of Sn, 0.05% to 0.50% of Co, and 0.0002% to 0.0100% of Mg in addition to the above-described elements.
  • Cu is an element which improves corrosion resistance of stainless steel and increases a high temperature strength especially in the intermediate temperature range by c-Cu precipitation, and thus Cu is added to the steel material if necessary. Since these effects are exhibited in the case where Cu is added in an amount of 0.4% or greater, the lower limit is set to 0.4%. The addition thereof in an amount greater than 2.0% leads to a deterioration in toughness of the steel material and an excessive reduction in elongation. In addition, ⁇ -Cu is excessively precipitated during the course of hot rolling, ⁇ 011 ⁇ -oriented grains are generated, and the r-value is reduced. Therefore, the upper limit of the addition amount of Cu is set to 2.0%. The content of Cu is desirably in a range of 0.5% to 1.5% in consideration of oxidation resistance and manufacturability.
  • Ni is an element which improves toughness and corrosion resistance, and thus Ni is added if necessary. Since the contribution to the toughness is exhibited in the case where the amount of Ni is 0.1% or greater, the lower limit is set to 0.1%. In the case where Ni is added in an amount greater than 2.0%, an austenite phase is generated and the r-value is reduced. Thus, the upper limit is set to 2.0%.
  • the content of Ni is desirably in a range of 0.1% to 0.5% in consideration of costs.
  • W is an element which is added if necessary in order to increase a high temperature strength, and the actions thereof are exhibited in the case where the amount of W is 0.1% or greater. Therefore, the lower limit of the addition amount of W is set to 0.1%. However, an excessive addition leads to a deterioration in toughness of the steel material and a reduction in elongation. In addition, too many Laves phases are generated, and thus ⁇ 011 ⁇ -oriented grains are easily generated and the r-value is reduced. Accordingly, the upper limit is set to 3.0%.
  • the content of W is desirably in a range of 0.1% to 2.0% in consideration of manufacturing costs and manufacturability.
  • Zr is an element which improves oxidation resistance and is added if necessary. Since the actions thereof are exhibited in the case where the content of Zr is in a range of 0.05% or greater, the lower limit is set to 0.05%. However, the addition in an amount greater than 0.30% causes a significant deterioration in manufacturability such as toughness and a pickling property, and also causes coarsening of a compound of Zr, carbon, and nitrogen, and thus the microstructure of the hot rolled and annealed sheet is grain-coarsened and the r-value is reduced. Therefore, the upper limit is set to 0.30%.
  • the content of Zr is desirably in a range of 0.05% to 0.20% in consideration of manufacturing costs.
  • Sn is an element which is added if necessary in order to increase a high temperature strength by segregation in a grain boundary. Since the actions thereof are exhibited in the case where the content of Sn is in a range of 0.05% or greater, the lower limit is set to 0.05%. However, the addition in an amount greater than 0.5% causes generation of Sn segregation, and thus ⁇ 011 ⁇ -oriented grains are generated in the segregation portion and the r-value is reduced. Therefore, the upper limit is set to 0.50%.
  • the content of Sn is desirably in a range of 0.10% to 0.30% in consideration of high temperature characteristics, manufacturing costs, and toughness.
  • Co Co + 0.05% to 0.50% in terms of mass %
  • Co is an element which improves a high temperature strength and is added in an amount of 0.05% or greater if necessary. However, since an excessive addition deteriorates workability, the upper limit is set to 0.50%.
  • the content of Co is desirably in a range of 0.05% to 0.30% in consideration of manufacturing costs.
  • Mg forms an Mg oxide together with Al in molten steel and Mg acts as a deoxidizer. Moreover, the fine crystallized Mg oxide serves as a nucleus and Nb-based precipitates or Ti-based precipitates are finely precipitated. When these are finely precipitated in the hot rolling process, the fine precipitates suppress recrystallization and formation of ⁇ 011 ⁇ -oriented grains in the hot rolling process and in the annealing process of a hot rolled sheet, and the fine precipitates contributes to formation of the non-recrystallized microstructure. Since this action is exhibited in the case where the amount of Mg is in a rage of 0.0002% or greater, the lower limit is set to 0.0002%.
  • the upper limit is set to 0.0100%.
  • the content of Mg is desirably in a range of 0.0003% to 0.0020% in consideration of refining costs.
  • an area ratio of crystal grains having a ⁇ 111 ⁇ orientation (hereinafter, simply referred to as ⁇ 111 ⁇ -oriented grains) in a region from the surface layer to t/4 (a region ranging from the surface to a depth of t/4) is in a range of 20% or greater, and an area ratio of ⁇ 111 ⁇ -oriented grains in a region from t/4 to t/2 (a region ranging from a depth of t/4 to the center in the sheet thickness direction) is in a range of 40% or greater. Furthermore, it is important that an area ratio of crystal grains having a ⁇ 011 ⁇ orientation (hereinafter, simply referred to as ⁇ 011 ⁇ -oriented grains) in the entire region in the sheet thickness direction is in a range of 15% or less.
  • the crystal grains having a ⁇ 111 ⁇ orientation are crystal grains in which the crystal orientation is indicated by plane index ⁇ 111 ⁇ , that is, crystal grains in which the sheet surface (the surface of the steel sheet) and the ⁇ 111 ⁇ plane are in parallel.
  • the crystal grains having a ⁇ 011 ⁇ orientation are crystal grains in which the crystal orientation is indicated by plane index ⁇ 011 ⁇ , that is, crystal grains in which the sheet surface and the ⁇ 011 ⁇ plane are in parallel.
  • the area ratios of the ⁇ 111 ⁇ -oriented grains and the ⁇ 011 ⁇ -oriented grains can be obtained as an area ratio of the crystal grains having the respective orientations in a plane which is perpendicular to the surface of the steel sheet and in parallel to the rolling direction.
  • r-value Lankford value which is an index of workability improvement is related to the recrystallization texture.
  • the r-value is improved by increasing the ratio of crystal grains having a ⁇ 111 ⁇ orientation.
  • the crystal orientation distribution was not uniform in the sheet thickness direction, and a sufficiently high r-value was not necessarily secured only with the control of the crystal orientation of a specific portion.
  • the relationship between the crystal orientation distribution in the sheet thickness direction of the cold rolled steel sheet (product sheet) and the r-value was examined in consideration of non-uniformity in the sheet thickness direction.
  • area ratios of ⁇ 111 ⁇ -oriented grains present in a region from the surface layer to t/4 (t is a sheet thickness) and in a region from t/4 to t/2 are required to be in a range of 20% or greater and in a range of 40% or greater, respectively.
  • an area ratio of ⁇ 011 ⁇ -oriented grains present in the entire region in the thickness direction is required to be in a range of 15% or less.
  • the area ratio of the ⁇ 111 ⁇ -oriented grains is preferably in a range of 25% or greater in the region from the surface layer to t/4 and the area ratio of the ⁇ 111 ⁇ -oriented grains is preferably in a range of 45% or greater in the region from t/4 to t/2, and the area ratio of the ⁇ 011 ⁇ -oriented grains are preferably in a range of 10% or less.
  • FIGS. 1 to 3 show the relationship between the area ratio (ratio) in the respective crystal orientations and an average r-value of a product sheet.
  • a JIS13-B tensile test piece is collected from a cold rolled and annealed sheet and a strain of 14.4% is applied in a rolling direction, in a direction at an angle of 45° with respect to the rolling direction, and in a direction at an angle of 90° with respect to the rolling direction. Then, an average r-value is calculated using the following Expressions (1) and (2).
  • W 0 represents a sheet width before pulling
  • W represents a sheet width after pulling
  • t 0 represents a sheet thickness before pulling
  • t represents a sheet thickness after pulling.
  • r 0 represents an r-value in the rolling direction
  • r 45 represents an r-value in a direction at an angle of 45° with respect to the rolling direction
  • r 90 represents an r-value in a direction at a right angle with respect to the rolling direction.
  • An exhaust component required to have a complicated shape can be subjected to sufficient working in the case where the average r-value is in a range of 1.2 or greater. Therefore, in this embodiment, a component having an average r-value of 1.2 or greater is judged to have excellent workability.
  • a plane in a direction parallel to the rolling direction is cut out of the product sheet at a right angle to the sheet surface, and orientations of crystal grains are identified over the entire region in the sheet thickness direction using a crystal orientation analysis apparatus EBSP (Electron Back Scatter diffraction Pattern) to determine area ratios of ⁇ 111 ⁇ -oriented grains and ⁇ 011 ⁇ -oriented grains.
  • EBSP Electro Back Scatter diffraction Pattern
  • FIG. 1 is a graph showing a relationship between an area ratio of ⁇ 111 ⁇ -oriented grains in a region from the surface layer to t/4 and an average r-value in a cold rolled ferritic stainless steel sheet of this embodiment
  • FIG. 2 is a graph showing a relationship between an area ratio of ⁇ 111 ⁇ -oriented grains in a region from t/4 to t/2 and an average r-value.
  • the steel component of the cold rolled ferritic stainless steel sheet used to examine the relationships shown in FIGS. 1 and 2 includes 0.007% of C, 0.27% of Si, 0.94% of Mn, 0.03% of P, 0.0006% of S, 17.3% of Cr, 1.8% of Mo, 0.08% of Ti, 0.47% of Nb, 0.01% of N, 0.001% of B, and 0.03% of Al (the balance being Fe and inevitable impurities).
  • the steel component of the cold rolled ferritic stainless steel sheet used to examine the relationship shown in FIG. 3 includes 0.007% of C, 0.27% of Si, 0.94% of Mn, 0.03% of P, 0.0006% of S, 17.3% of Cr, 1.8% of Mo, 0.08% of Ti, 0.47% of Nb, 0.01% of N, 0.001% of B, and 0.03% of Al (the balance being Fe and inevitable impurities).
  • the manufacturing method was examined as well as the texture and the component composition of the cold rolled steel sheet (cold rolled sheet); and as a result, it was found that the texture of the cold rolled sheet is influenced by the microstructure of the hot rolled steel sheet (hot rolled sheet for a material for cold rolling) which is a raw material of the cold rolled steel sheet, and thus the r-value of the cold rolled sheet is influenced.
  • the microstructure in a region from t′/4 to t′/2 (t′ is a sheet thickness of the hot rolled sheet for a material for cold rolling) in the hot rolled sheet for a material for cold rolling is a non-recrystallized microstructure, the cold rolled steel sheet manufactured from such a hot rolled sheet for a material for cold rolling has a high r-value.
  • the region from t′/4 to t′/2 is a region ranging from a depth of t/4 from the surface of the steel sheet to the center in the sheet thickness direction.
  • the method of manufacturing a hot rolled ferritic stainless steel sheet for a material for cold rolling of this embodiment includes: manufacturing ferritic stainless steel having the above-described steel composition; after the manufacturing of the steel, subjecting a semi-finished product (slab) which is cast to hot rolling under conditions where a heating temperature of a slab is set to be in a range of 1200° C. to 1300° C. and a finishing temperature is set to be in a range of 800° C. to 950° C. so as to form a hot rolled sheet; coiling the hot rolled sheet at a coiling temperature of 500° C. or lower; and then, annealing the hot rolled sheet at a temperature of 925° C. to 1000° C.
  • the hot rolling a hot rolling strain caused by rolling is excessively introduced in the case where a heating temperature of a slab is in a range of lower than 1200° C., and thus it becomes difficult to perform the subsequent control of microstructure and surface scratches become a problem. Accordingly, the lower limit is set to 1200° C. In the case where the heating temperature is in a range of higher than 1300° C., the microstructure after the hot rolling is grain-coarsened. Thus, the development of the ⁇ 111 ⁇ texture is suppressed and the structure may be a recrystallized microstructure. Accordingly, the upper limit is set to 1300° C.
  • the heating temperature is desirably in a range of 1230° C. to 1280° C. in consideration of productivity.
  • the steel sheet is coiled in a coil shape.
  • the finishing temperature is in a range of lower than 800° C.
  • surface scratches become a problem, and thus the lower limit of the finishing temperature is set to 800° C.
  • the microstructure after the hot rolling is grain-coarsened.
  • the upper limit is set to 950° C.
  • the finishing temperature is desirably in a range of 850° C. to 930° C. in consideration of productivity.
  • the coiling temperature is set to be in a range of 500° C. or lower from the viewpoint of the suppression of recovery of the hot rolled microstructure and the toughness of the hot rolled sheet. That is, in the invention, in the case where the coiling temperature is set to be a low temperature of 500° C. or lower, the ⁇ 111 ⁇ texture obtained through the hot rolling process is not recovered, and while the texture is maintained, the subsequent processes can be proceeded.
  • the coiling temperature is desirably in a range of 400° C. to 480° C. in consideration of productivity, toughness, and coil shape.
  • the coiling temperature is in a range of higher than 500° C.
  • the annealing temperature is appropriate in the subsequent annealing process of a hot rolled sheet
  • ⁇ 110 ⁇ -oriented grains caused by a hot rolling shear strain generated in the vicinity of the surface layer portion of the sheet thickness are grown during the course of cooling to the room temperature after coiling of a hot rolled sheet, ⁇ 110 ⁇ -oriented grains encroach another orientation in the subsequent annealing process; and thereby, ⁇ 110 ⁇ -oriented grains remain in the product sheet.
  • the coiling temperature is set to be in a range of 500° C. or lower.
  • cooling is desirably performed at a cooling rate of 50° C./sec or greater.
  • the non-uniformity in the microstructure in the sheet thickness direction has a large influence on the r-value of the product sheet, and also found that as described above, in the case where the microstructure in a region from t′/4 to t′/2 (t′ is a sheet thickness) is a non-recrystallized microstructure, the cold rolled steel sheet, that is, the product sheet obtains a high r-value.
  • FIG. 4 shows a relationship between an annealing temperature of a hot rolled sheet and an average r-value of a product sheet.
  • steel A represented by the reference symbols ⁇ and ⁇ in FIG. 4
  • steel B has a composition including 0.007% of C, 0.25% of Si, 0.95% of Mn, 0.03% of P, 0.0006% of 5, 17.3% of Cr, 1.8% of Mo, 0.08% of Ti, 0.47% of Nb, 0.01% of N, 0.0010% of B, and 0.03% of Al (the balance being Fe and inevitable impurities).
  • Steel B represented by the reference symbols ⁇ and ⁇ in FIG.
  • FIG. 4 also shows a microstructure state of the region from t′/4 to t′/2 after annealing of a hot rolled sheet.
  • the reference symbols ⁇ and ⁇ represent a non-recrystallized microstructure, and the reference symbols ⁇ and ⁇ represent a recrystallized microstructure.
  • the recrystallization temperature varies with the steel component.
  • an appropriate annealing temperature of a hot rolled sheet can be found in the range of 925° C. to 1000° C. That is, a temperature can be found at which a non-recrystallized microstructure (which does not change into a full-recrystallized microstructure), that is an appropriate microstructure for the hot rolled sheet for a material for cold rolling, is obtained at a depth of t′/4 to t′/2 (t′ is a sheet thickness of the hot rolled sheet for a material for cold rolling).
  • t′ is a sheet thickness of the hot rolled sheet for a material for cold rolling.
  • the annealing temperature of a hot rolled sheet is too low or the annealing of a hot rolled sheet is omitted, many ⁇ 110 ⁇ -oriented grains, which are caused by the hot rolling shear strain generated in the vicinity of the surface layer portion of the sheet thickness, remain in the product sheet after annealing of a cold rolled sheet. Since these oriented grains lead to a reduction in the r-value, the annealing of a hot rolled sheet is required to be performed at a temperature of 800° C. or higher.
  • the lower limit of the annealing temperature of a hot rolled sheet is set to 925° C.
  • the annealing of a hot rolled sheet is performed at a temperature of higher than 1000° C.
  • the microstructure of the region from t′/4 to t′/2 is recrystallized, and thus the recrystallized grains in the surface layer are coarsened and a compound of Fe and Nb (Fe 2 Nb), which is called as Laves phase, is completely dissolved after the annealing of a hot rolled sheet.
  • the r-value is reduced.
  • Laves phase coarsely generated through the annealing of a hot rolled sheet becomes a nucleus generation site of the recrystallization texture during the annealing of a cold rolled sheet, it is desirably that Laves phase be precipitated in the material for cold rolling.
  • the upper limit of the annealing temperature of a hot rolled sheet is set to 1000° C. in consideration of these points. Furthermore, since coarsening of crystal grains and promotion of scale generation due to high temperature annealing lead to a reduction in surface quality such as fracture of the sheet and scale residues, the annealing temperature of a hot rolled sheet is desirably in a range of 925° C. to 980° C. in consideration of toughness of the hot rolled sheet and a pickling property.
  • the hot rolled sheet for a material for cold rolling is subjected to cold rolling to have a thickness of 2 mm, and is subjected to a heat treatment at a temperature of 1000° C. to 1100° C. according to the steel component so that the grain size number becomes in a range of 5 to 7. Thereby, a product sheet is formed.
  • the cold rolling reduction ratio is set to be in a range of 60% or greater in order to obtain recrystallization nuclei which grow into the ⁇ 111 ⁇ -oriented crystals in the cold rolled sheet. That is, in the case where the cold rolling reduction ratio is too low, recrystallization nuclei for recrystallization into ⁇ 111 ⁇ -oriented grains through the following annealing process cannot be sufficiently generated, and thus the r-value of the product sheet is not sufficiently improved. Therefore, it is important that the rolling reduction ratio is set to be in a range of 60% or greater.
  • the rolling reduction ratio is desirably in a range of 60% to 80% in consideration of productivity and anisotropy.
  • annealing of the cold rolled sheet is performed at a temperature of 1000° C. to 1100° C.
  • the heat treatment temperature is determined according to the steel component in order to obtain a recrystallized microstructure.
  • the temperature is in a range of lower than 1000° C.
  • a non-recrystallized microstructure is obtained in the steel component of the invention, and thus the lower limit is set to 1000° C.
  • the upper limit is set to 1100° C.
  • the heat treatment temperature is desirably in a range of 1010° C. to 1070° C. in consideration of elongation and a pickling property.
  • the thickness of the slab, the thickness of the hot rolled sheet, and the like may be appropriately designed.
  • the roll roughness and the roll diameter of a used work roll, a rolling oil, the number of passes of rolling, the rolling rate, the rolling temperature, and the like may be appropriately selected.
  • bright annealing may be performed so that the annealing is performed under a non-oxidation atmosphere such as hydrogen gas or nitrogen gas, or the annealing may be performed in the air.
  • steel having a component composition shown in Table 1 was melted to cast a slab, and the slab was subjected to hot rolling to form a hot rolled sheet having a thickness of 5.0 mm. Thereafter, the hot rolled sheet was subjected to continuous annealing, and then subjected to pickling. The resulting material was subjected to cold rolling to have a thickness of 2.0 mm and was subjected to continuous annealing and pickling to form a product sheet.
  • steels Nos. 1 to 13 are out of the scope of the invention
  • steels Nos. 14 to 32 are out of the scope of the invention.
  • the component compositions out of the scope of the invention are indicated by an underline.
  • the hot rolling conditions were within the scope of the invention.
  • the heating temperature of a slab was set to be in a range of 1200° C. to 1300° C.
  • the finishing temperature was set to be in a range of 800° C. to 950° C.
  • the coiling temperature was set to be in a range of 500° C. or lower.
  • the annealing temperature was set to be in a range of 800° C. to 1000° C. and to be a temperature at which a non-recrystallized microstructure is obtained in a region of a depth of t′/2 to t′/4 (t′: a sheet thickness of a hot rolled sheet).
  • cold rolling was performed at a rolling reduction ratio of 60%.
  • the annealing of a cold rolled sheet was performed at a temperature of 1000° C. to 1100° C. according to the steel component so that a recrystallized microstructure is obtained.
  • the methods of measuring the ratio of the crystal-oriented grains and the average r-value are the same as the above-described method.
  • a plane in a direction parallel to the rolling direction was cut out of the obtained product sheet at a right angle to the sheet surface, and orientations of crystal grains were identified over the entire region in the sheet thickness direction using a crystal orientation analysis apparatus EBSP to determine area ratios of ⁇ 111 ⁇ -oriented grains and ⁇ 011 ⁇ -oriented grains.
  • a high temperature tensile test piece was collected in the rolling direction from the obtained product sheet, and a high temperature tensile test was performed at 900° C. based on JIS G 0567 to measure a 0.2% proof stress.
  • oxidation resistance test a continuous oxidation test was performed at 900° C. for 200 hours in the air based on JIS Z 2281 to evaluate breakaway and occurrence of scale peeling.
  • the steel having a component composition specified in the invention has a higher average r-value and more excellent workability than those in the comparative examples.
  • the high temperature strength is also high and the oxidation resistance is also excellent.
  • the comparative steels Nos. 14, 15, 17, 18, and 20 to 31 have a steel component which is out of the scope of the invention, the crystal orientation ratio of the product sheet is out of the scope of the invention, and thus the average r-value of the product sheet is in a range of less than 1.2.
  • the comparative steels Nos. 16, 19, and 32 have a satisfactory r-value, but are insufficient in oxidation resistance and in high temperature strength. When these are applied as an exhaust component, there is a concern that breakage may occur during use.
  • the recrystallization state is a microstructure state in the region from t′/2 to t′/4.
  • test Nos. P33 and P34 in which all of the manufacturing conditions specified in the invention are satisfied have a higher average r-value and more excellent workability than those of the comparative examples.
  • the invention it is possible to efficiently provide a heat-resistant ferritic stainless steel sheet having excellent workability without requiring special new facilities. Therefore, when a cold rolled steel sheet to which the invention is applied is applied to, especially, an exhaust member, a social contribution ratio such as a reduction in manufacturing costs can be increased. That is, the invention has sufficient industrial applicability.

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US20150020992A1 (en) * 2012-03-23 2015-01-22 Salzgitter Flachstahl Gmbh Non-scaling heat-treatable steel and method for producing a non-scaling component from said steel
JP2018530524A (ja) * 2015-08-21 2018-10-18 アルデイラ セラピューティクス， インコーポレイテッド アルデヒドコンジュゲートおよびその使用
JP2019002053A (ja) * 2017-06-16 2019-01-10 新日鐵住金ステンレス株式会社 フェライト系ステンレス鋼板、鋼管および排気系部品用フェライト系ステンレス部材ならびにフェライト系ステンレス鋼板の製造方法
EP3388542A4 (en) * 2016-02-02 2019-11-06 Nisshin Steel Co., Ltd. FERRITIC STAINLESS STEEL SHEET CONTAINING HOT ROLLED NAMIN AND ITS MANUFACTURING METHOD AND FERRITIC STAINLESS STEEL SHEET CONTAINING COLD LAMINATED NU AND METHOD FOR MANUFACTURING THE SAME
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US10837075B2 (en) 2014-02-05 2020-11-17 Jfe Steel Corporation Hot rolled and annealed ferritic stainless steel sheet, method of producing same, and cold rolled and annealed ferritic stainless steel sheet
US20210032718A1 (en) * 2018-03-30 2021-02-04 Nippon Steel Stainless Steel Corporation Ferritic stainless steel sheet and production method thereof, and ferritic stainless member
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* Cited by examiner, † Cited by third party
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KR20160076792A (ko) * 2014-12-23 2016-07-01 주식회사 포스코 페라이트계 스테인리스강 및 그 제조방법
KR20160078589A (ko) * 2014-12-24 2016-07-05 주식회사 포스코 가공성이 우수한 페라이트계 스테인리스 강재 및 그 제조방법
DE102016110661A1 (de) * 2016-06-09 2017-12-14 Salzgitter Flachstahl Gmbh Verfahren zur Herstellung eines kaltgewalzten Stahlbandes aus einem hochfesten, manganhaltigen Stahl
KR102400403B1 (ko) * 2016-12-21 2022-05-23 제이에프이 스틸 가부시키가이샤 페라이트계 스테인리스 강
JP6841150B2 (ja) * 2017-04-28 2021-03-10 日本製鉄株式会社 耐熱部材用フェライト系ステンレス鋼板
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WO2020194484A1 (ja) * 2019-03-26 2020-10-01 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼板およびその製造方法
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JP7468470B2 (ja) 2021-06-28 2024-04-16 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼板およびその製造方法

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09263900A (ja) * 1996-03-29 1997-10-07 Kawasaki Steel Corp 耐リジング性および加工性に優れたフェライト系ステンレス鋼板およびその製造方法
JP2001181808A (ja) * 1999-12-17 2001-07-03 Nippon Steel Corp リジング特性と深絞り性に優れたフェライト系ステンレス鋼板及びその製造方法
JP2001294991A (ja) * 2000-04-13 2001-10-26 Nippon Steel Corp 成形性とリジング特性に優れたフェライト系ステンレス鋼板及びその製造方法
US20020012602A1 (en) * 2000-01-22 2002-01-31 Akihiko Takahashi Fuel tank made of ferritic stainless steel
US20020144756A1 (en) * 1999-12-03 2002-10-10 Kawasaki Steel Corporation Ferritic stainless steel plate and method
JP2003155543A (ja) * 2001-11-19 2003-05-30 Nisshin Steel Co Ltd 深絞り性に優れ面内異方性の小さいフェライト系ステンレス鋼及びその製造方法
US20030155543A1 (en) * 2000-02-23 2003-08-21 Fumio Kato Slide gate valve for powder and granular material
US20050173033A1 (en) * 2002-06-17 2005-08-11 Yoshihiro Yazawa Ferritic stainless steel plate with ti and method for production thereof
JP2008138270A (ja) * 2006-12-05 2008-06-19 Nippon Steel & Sumikin Stainless Steel Corp 加工性に優れた高強度ステンレス鋼板およびその製造方法
JP2008190003A (ja) * 2007-02-06 2008-08-21 Nippon Steel & Sumikin Stainless Steel Corp 耐すきま腐食性に優れたフェライト系ステンレス鋼
US20110110812A1 (en) * 2008-07-23 2011-05-12 Nobulhiko Hiraide Ferrite stainless steel for use in producing urea water tank
WO2012018074A1 (ja) * 2010-08-06 2012-02-09 新日鐵住金ステンレス株式会社 フェライト系ステンレス鋼

Family Cites Families (35)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0694574B2 (ja) * 1986-12-26 1994-11-24 川崎製鉄株式会社 プレス成形性のきわめて優れたフエライト系ステンレス鋼板の製造方法
JP2696584B2 (ja) 1990-03-24 1998-01-14 日新製鋼株式会社 低温靭性，溶接性および耐熱性に優れたフエライト系耐熱用ステンレス鋼
JP3219099B2 (ja) 1991-07-26 2001-10-15 日新製鋼株式会社 耐熱性， 低温靭性および溶接性に優れたフエライト系耐熱用ステンレス鋼
JP3152576B2 (ja) 1995-01-19 2001-04-03 川崎製鉄株式会社 Ｎｂ含有フェライト鋼板の製造方法
JPH09279312A (ja) 1996-04-18 1997-10-28 Nippon Steel Corp 高温特性、耐食性及び加工性に優れたフェライト系ステンレス鋼
JP3926492B2 (ja) * 1998-12-09 2007-06-06 新日鐵住金ステンレス株式会社 断続加熱時の高温強度に優れ、断続加熱時にも剥離し難い酸化スケールを有するフェライト系ステンレス鋼板
US6426039B2 (en) 2000-07-04 2002-07-30 Kawasaki Steel Corporation Ferritic stainless steel
JP3804408B2 (ja) 2000-07-13 2006-08-02 Ｊｆｅスチール株式会社 成形性に優れたＣｒ含有耐熱耐食鋼板の製造方法
EP1571227B1 (en) 2002-12-12 2007-02-21 Nippon Steel & Sumikin Stainless Steel Corporation Cr-CONTAINING HEAT-RESISTANT STEEL SHEET EXCELLENT IN WORKABILITY AND METHOD FOR PRODUCTION THEREOF
JP4309140B2 (ja) 2003-01-15 2009-08-05 新日鐵住金ステンレス株式会社 自動車排気系機器用フェライト系ステンレス鋼
JP4519505B2 (ja) 2004-04-07 2010-08-04 新日鐵住金ステンレス株式会社 成形性に優れるフェライト系ステンレス鋼板およびその製造方法
CN1331978C (zh) 2004-12-09 2007-08-15 中国石油天然气股份有限公司 一种钻井液用聚合醇润滑抑制剂及其应用
JP4721917B2 (ja) * 2005-01-24 2011-07-13 新日鐵住金ステンレス株式会社 成形時の面内異方性が小さく耐リジング性及び耐肌荒れ性に優れた低炭素低窒素フェライト系ステンレス鋼薄板及びその製造方法
JP4498950B2 (ja) * 2005-02-25 2010-07-07 新日鐵住金ステンレス株式会社 加工性に優れた排気部品用フェライト系ステンレス鋼板およびその製造方法
JP4948998B2 (ja) 2006-12-07 2012-06-06 日新製鋼株式会社 自動車排ガス流路部材用フェライト系ステンレス鋼および溶接鋼管
JP5010301B2 (ja) 2007-02-02 2012-08-29 日新製鋼株式会社 排ガス経路部材用フェライト系ステンレス鋼および排ガス経路部材
JP5297630B2 (ja) * 2007-02-26 2013-09-25 新日鐵住金ステンレス株式会社 耐熱性に優れたフェライト系ステンレス鋼板
JP4949124B2 (ja) * 2007-05-22 2012-06-06 新日鐵住金ステンレス株式会社 形状凍結性に優れた高強度複相ステンレス鋼板及びその製造方法
JP5012243B2 (ja) 2007-06-19 2012-08-29 Ｊｆｅスチール株式会社 高温強度、耐熱性および加工性に優れるフェライト系ステンレス鋼
EP2182085B1 (en) 2007-08-20 2017-10-11 JFE Steel Corporation Ferritic stainless steel plate excellent in punchability and process for production of the same
JP5396752B2 (ja) 2007-10-02 2014-01-22 Ｊｆｅスチール株式会社 靭性に優れたフェライト系ステンレス鋼およびその製造方法
JP5178157B2 (ja) 2007-11-13 2013-04-10 日新製鋼株式会社 自動車排ガス経路部材用フェライト系ステンレス鋼材
JP5025671B2 (ja) 2008-02-13 2012-09-12 新日鐵住金ステンレス株式会社 高温強度に優れたフェライト系ステンレス鋼板およびその製造方法
JP5125600B2 (ja) 2008-02-25 2013-01-23 Ｊｆｅスチール株式会社 高温強度、耐水蒸気酸化性および加工性に優れるフェライト系ステンレス鋼
JP5141296B2 (ja) 2008-02-25 2013-02-13 Ｊｆｅスチール株式会社 高温強度と靭性に優れるフェライト系ステンレス鋼
JP5274074B2 (ja) 2008-03-28 2013-08-28 新日鐵住金ステンレス株式会社 耐酸化性に優れた耐熱性フェライト系ステンレス鋼板
JP2011068948A (ja) 2009-09-25 2011-04-07 Nisshin Steel Co Ltd スターリングエンジンの熱交換器
JP4831256B2 (ja) * 2010-01-28 2011-12-07 Ｊｆｅスチール株式会社 靭性に優れた高耐食性フェライト系ステンレス熱延鋼板
CN102741445B (zh) * 2010-02-02 2014-12-17 杰富意钢铁株式会社 韧性优异的高耐腐蚀性铁素体系不锈钢冷轧钢板及其制造方法
JP5658893B2 (ja) * 2010-03-11 2015-01-28 新日鐵住金ステンレス株式会社 耐熱性に優れたフェライト系ステンレス鋼板およびその製造方法
CN102791897A (zh) 2010-03-11 2012-11-21 新日铁住金不锈钢株式会社 耐氧化性优异的铁素体系不锈钢板和耐热性优异的铁素体系不锈钢板及其制造方法
JP2011190524A (ja) * 2010-03-17 2011-09-29 Nisshin Steel Co Ltd 耐酸化性、二次加工脆性および溶接部の靭性に優れたフェライト系ステンレス鋼
JP2010156059A (ja) 2010-03-19 2010-07-15 Jfe Steel Corp 温間金型潤滑成形用鉄基粉末混合物
BR112012024625B1 (pt) * 2010-03-29 2019-01-08 Nippon Steel & Sumikin Sst processo de produção de uma chapa de aço inoxidável ferrítico que é excelente em brilho de superfície e resistência à corrosão
JP5703075B2 (ja) 2011-03-17 2015-04-15 新日鐵住金ステンレス株式会社 耐熱性に優れたフェライト系ステンレス鋼板

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09263900A (ja) * 1996-03-29 1997-10-07 Kawasaki Steel Corp 耐リジング性および加工性に優れたフェライト系ステンレス鋼板およびその製造方法
US20020144756A1 (en) * 1999-12-03 2002-10-10 Kawasaki Steel Corporation Ferritic stainless steel plate and method
JP2001181808A (ja) * 1999-12-17 2001-07-03 Nippon Steel Corp リジング特性と深絞り性に優れたフェライト系ステンレス鋼板及びその製造方法
US20020012602A1 (en) * 2000-01-22 2002-01-31 Akihiko Takahashi Fuel tank made of ferritic stainless steel
US20030155543A1 (en) * 2000-02-23 2003-08-21 Fumio Kato Slide gate valve for powder and granular material
JP2001294991A (ja) * 2000-04-13 2001-10-26 Nippon Steel Corp 成形性とリジング特性に優れたフェライト系ステンレス鋼板及びその製造方法
JP2003155543A (ja) * 2001-11-19 2003-05-30 Nisshin Steel Co Ltd 深絞り性に優れ面内異方性の小さいフェライト系ステンレス鋼及びその製造方法
US20050173033A1 (en) * 2002-06-17 2005-08-11 Yoshihiro Yazawa Ferritic stainless steel plate with ti and method for production thereof
JP2008138270A (ja) * 2006-12-05 2008-06-19 Nippon Steel & Sumikin Stainless Steel Corp 加工性に優れた高強度ステンレス鋼板およびその製造方法
JP2008190003A (ja) * 2007-02-06 2008-08-21 Nippon Steel & Sumikin Stainless Steel Corp 耐すきま腐食性に優れたフェライト系ステンレス鋼
US20110110812A1 (en) * 2008-07-23 2011-05-12 Nobulhiko Hiraide Ferrite stainless steel for use in producing urea water tank
WO2012018074A1 (ja) * 2010-08-06 2012-02-09 新日鐵住金ステンレス株式会社 フェライト系ステンレス鋼
US20130129560A1 (en) * 2010-08-06 2013-05-23 Tooru matsuhashi Ferritic stainless steel

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10822681B2 (en) 2012-03-23 2020-11-03 Salzgitter Flachstahl Gmbh Non-scaling heat-treatable steel and method for producing a non-scaling component from said steel
US10036085B2 (en) * 2012-03-23 2018-07-31 Salzgitter Flachstahl Gmbh Non-scaling heat-treatable steel and method for producing a non-scaling component from said steel
US20150020992A1 (en) * 2012-03-23 2015-01-22 Salzgitter Flachstahl Gmbh Non-scaling heat-treatable steel and method for producing a non-scaling component from said steel
US10837075B2 (en) 2014-02-05 2020-11-17 Jfe Steel Corporation Hot rolled and annealed ferritic stainless steel sheet, method of producing same, and cold rolled and annealed ferritic stainless steel sheet
US10648053B2 (en) 2014-03-26 2020-05-12 Nippon Steel & Sumikin Stainless Steel Corporation Rolled ferritic stainless steel sheet, method for producing the same, and flange part
JP2018530524A (ja) * 2015-08-21 2018-10-18 アルデイラ セラピューティクス， インコーポレイテッド アルデヒドコンジュゲートおよびその使用
EP3388542A4 (en) * 2016-02-02 2019-11-06 Nisshin Steel Co., Ltd. FERRITIC STAINLESS STEEL SHEET CONTAINING HOT ROLLED NAMIN AND ITS MANUFACTURING METHOD AND FERRITIC STAINLESS STEEL SHEET CONTAINING COLD LAMINATED NU AND METHOD FOR MANUFACTURING THE SAME
EP3708690A1 (en) * 2016-02-02 2020-09-16 Nippon Steel Stainless Steel Corporation Cold rolled nb-containing ferritic stainless steel sheet and method for producing same
JP2019002053A (ja) * 2017-06-16 2019-01-10 新日鐵住金ステンレス株式会社 フェライト系ステンレス鋼板、鋼管および排気系部品用フェライト系ステンレス部材ならびにフェライト系ステンレス鋼板の製造方法
EP3699311A4 (en) * 2017-12-20 2020-08-26 Posco FERRITIC STAINLESS STEEL HAVING IMPROVED WORKABILITY FOR TUBE EXPANSION AND ITS MANUFACTURING PROCESS
US12123067B2 (en) 2017-12-20 2024-10-22 Posco Co., Ltd Ferritic stainless steel having improved pipe-expanding workability and method for manufacturing same
US20210032718A1 (en) * 2018-03-30 2021-02-04 Nippon Steel Stainless Steel Corporation Ferritic stainless steel sheet and production method thereof, and ferritic stainless member
US11643699B2 (en) * 2018-03-30 2023-05-09 Nippon Steel Stainless Steel Corporation Ferritic stainless steel sheet and production method thereof, and ferritic stainless member
US20210348249A1 (en) * 2018-09-19 2021-11-11 Posco Ferrite-based stainless steel having excellent processability and high-temperature strength and method for manufacturing same
US12043875B2 (en) * 2018-09-19 2024-07-23 Posco Co., Ltd Ferrite-based stainless steel having excellent processability and high-temperature strength and method for manufacturing same
EP3901292A4 (en) * 2018-12-21 2022-11-23 NIPPON STEEL Stainless Steel Corporation CR-BASED STAINLESS STEEL WITH EXCELLENT RESISTANCE TO HYDROGEN EMBRITTLEMENT

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