US20200277690A1 - Nb-CONTAINING FERRITIC STAINLESS STEEL SHEET AND MANUFACTURING METHOD THEREFOR - Google Patents

Nb-CONTAINING FERRITIC STAINLESS STEEL SHEET AND MANUFACTURING METHOD THEREFOR Download PDF

Info

Publication number
US20200277690A1
US20200277690A1 US16/086,086 US201716086086A US2020277690A1 US 20200277690 A1 US20200277690 A1 US 20200277690A1 US 201716086086 A US201716086086 A US 201716086086A US 2020277690 A1 US2020277690 A1 US 2020277690A1
Authority
US
United States
Prior art keywords
less
steel sheet
rolled
annealing
hot
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/086,086
Other languages
English (en)
Inventor
Yutaka YAKUSHIJIN
Akira Hironaka
Kazunari Imakawa
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Stainless Steel Corp
Original Assignee
Nippon Steel Stainless Steel Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nippon Steel Stainless Steel Corp filed Critical Nippon Steel Stainless Steel Corp
Assigned to NISSHIN STEEL CO., LTD. reassignment NISSHIN STEEL CO., LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: HIRONAKA, AKIRA, IMAKAWA, KAZUNARI, YAKUSHIJIN, Yutaka
Assigned to NIPPON STEEL NISSHIN CO., LTD. reassignment NIPPON STEEL NISSHIN CO., LTD. CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: NISSHIN STEEL CO., LTD.
Assigned to NIPPON STEEL STAINLESS STEEL CORPORATION reassignment NIPPON STEEL STAINLESS STEEL CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NIPPON STEEL NISSHIN CO., LTD.
Publication of US20200277690A1 publication Critical patent/US20200277690A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • 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
    • 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
    • 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
    • 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
    • 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
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • 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
    • 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
    • C21D8/021—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips involving a particular fabrication or treatment of ingot or slab
    • 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
    • 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
    • C21D8/0226—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
    • 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
    • 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
    • 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
    • C21D8/0273—Final recrystallisation annealing
    • 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
    • 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
    • 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
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • 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
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • 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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • 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
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • 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
    • C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
    • 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
    • C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium 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
    • C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
    • 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
    • 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
    • C22C38/42—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
    • C22C38/48—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
    • C22C38/54—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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/004—Dispersions; Precipitations
    • 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 hot-rolled steel sheet of a Nb-containing ferritic stainless steel, and a manufacturing method for the same.
  • the invention also relates to a manufacturing method for a cold-rolled and annealed steel sheet using the hot-rolled steel sheet as a raw material steel sheet.
  • a Nb-containing ferritic stainless steel has good workability due to C and N fixed therein, and is useful for various purposes including kitchen members, home appliance members, building members, and the like.
  • a Nb-containing ferritic stainless steel is also useful for various purposes of heat resistant materials, such as an automobile exhaust gas path member, due to the excellent high temperature strength thereof.
  • the Nb-containing ferritic stainless steel is being demanded to have excellent workability for applying to various types of press working. It is significantly effective that a steel sheet applied to severe press working has a large plastic strain ratio r as a characteristic feature thereof.
  • PTL 1 described a method of subjecting a raw material having a recrystallization ratio of from 10 to 90% to cold rolling and annealing to make the total precipitates of the product steel sheet of from 0.05 to 0.60%.
  • PTL 2 describes a method of subjecting a hot-rolled sheet to cold rolling with a large diameter roll with omission of annealing, so as to control to a particular texture.
  • PTL 3 describes a method of subjecting a hot-rolled sheet obtained through hot rolling at an extraction temperature of 1,200° C. or more and a coiling temperature of 500° C.
  • a cold worked member of a ferritic stainless steel sheet may have surface unevenness called ridging occurring thereon in some cases, which often becomes a problem.
  • a steel sheet for an automobile exhaust gas path member is also demanded to have improved ridging resistance. It is difficult to improve the ridging resistance by the ordinary techniques for improving the r value represented by PTLs 1 to 3 described above.
  • PTL 4 describes an improving technique of ridging resistance that is effective also for a Nb-containing ferritic stainless steel sheet.
  • the technique includes hot rolling in an ordinary method, and then annealing for the hot-rolled sheet by a special two-stage method combining preliminary annealing for a short period of time and main annealing for one hour or more.
  • the technique is difficult to improve the r value.
  • PTL 5 describes a technique of improving spinning workability by a process of hot-rolling a cast slab heated to a temperature of from 1,000 to 1,200° C.
  • Ti is added in a slight amount in combination to a Nb-added steel to suppress the size and the density of the composite precipitate mainly containing TiN, and thereby the workability and the toughness due to TiN are improved (paragraph 0015).
  • the literature describes that it is important that the average cooling rate in the temperature range, in which TiN becomes coarse on casting, is 5° C. per second or more (paragraph 0060). However, the literature does not teach a method for improving the r value or the ridging resistance of a Nb-containing ferritic stainless steel sheet.
  • An object of the invention is to enhance simultaneously an r value and ridging resistance of a Nb-containing ferritic stainless steel sheet.
  • the present inventors have found that for achieving the aforementioned object, it is significantly effective that a Nb-containing precipitate formed in a cast slab is allowed to remain in a hot-rolled steel sheet in a large amount.
  • the heating temperature of the slab before hot rolling is 1,150° C. or less, at which the Nb-containing precipitate readily remains without forming solid solution, the Nb-containing precipitate can be allowed to remain in the hot-rolled steel sheet in such an amount that is substantially equivalent to that in the cast slab.
  • the hot-rolled steel sheet having a large amount of the Nb-containing precipitate remaining therein is in such a state that the strain is concentrated around the precipitate over the substantially entire region inside the steel sheet.
  • the concentrated strain contributes to the formation of recrystallization nuclei in every sites inside the steel sheet in the annealing for the hot-rolled sheet, and recrystallized grains are formed over the steel sheet.
  • the recrystallized grains grow, a fine random recrystallized structure is formed, thereby providing a hot-rolled and annealed steel sheet that is suppressed in formation of colonies (crystal grain groups having approximate crystallographic orientation).
  • colonies crystal grain groups having approximate crystallographic orientation
  • the invention has been completed based on the aforementioned knowledge.
  • the invention provides a ferritic stainless steel raw material steel sheet for annealing and cold rolling, having a chemical composition containing, in terms of percentage by mass, from 0.004 to 0.030% of C, 1.50% or less of Si, 1.50% or less of Mn, 0.040% or less of P, 0.010% or less of S, from 12.0 to 25.0% of Cr, from 0.005 to 0.025% of N, from 0.20 to 0.80% of Nb, 0.10% or less of Al, from 0 to 3.0% of Mo, from 0 to 2.0% of Cu, from 0 to 2.0% of Ni, from 0 to 0.30% of Ti, from 0 to 0.0030% of B, and the balance of Fe, with unavoidable impurities, and having an existing amount of a Nb-containing precipitate of 0.20% by mass or more.
  • the raw material steel sheet may have a sheet thickness, for example, of from 3.0 to 6.0 mm.
  • the “ferritic stainless steel raw material steel sheet for annealing and cold rolling” means a stainless steel sheet interim product that is to be subjected to annealing in the subsequent step and then to cold rolling in the step of applying heat history or process history. Representative examples thereof include a hot-rolled steel sheet, i.e., a steel sheet in an untouched state after hot rolling (so-called as hot). Before the cold rolling, a descaling step, such as acid pickling, is generally performed.
  • the Nb-containing precipitate is a precipitate phase having Nb as a constitutional element, and corresponds to a carbide, a nitride, a carbonitride, and an intermetallic compound (such as a Laves phase) of Nb. Whether or not the precipitate phase is the Nb-containing precipitate can be confirmed by such an analysis method as EDX (energy dispersive fluorescent X-ray analysis) and the like.
  • EDX energy dispersive fluorescent X-ray analysis
  • the existing amount of the Nb-containing precipitate in the steel sheet can be obtained by an electrolytic extraction method in the following manner.
  • a potential of from ⁇ 100 mV to 400 mV is applied to a specimen having a known mass collected from the steel sheet with respect to a saturated calomel electrode (SCE), the matrix (metal matrix) of the specimen is completely dissolved, then the liquid containing undissolved matters is filtered off with a Micropore filter having a pore diameter of 0.2 m, and the solid content remaining on the filter is collected as an extraction residue.
  • the mass ratio of the extraction residue with respect to the mass of the specimen having been dissolved is designated as the existing amount (% by mass) of the Nb-containing precipitate.
  • the extraction residue obtained in the aforementioned manner can be substantially a residue formed of a Nb-containing precipitate. Therefore, the mass ratio of the extraction residue collected by the electrolytic extraction method described later is defined as the existing amount of the Nb-containing precipitate.
  • the Nb-containing precipitate preferably has an average particle diameter of from 2.0 to 10.0 ⁇ m in terms of circle equivalent diameter.
  • a circle equivalent diameter of a precipitate is the diameter of the circle having an area that is equal to the area of the precipitate particle measured on an observation image plane.
  • the average particle diameter can be obtained in the following manner.
  • the cross sectional surface (L cross sectional surface) of the steel sheet that is in parallel to the rolling direction and the thickness direction thereof is observed with SEM, all the Nb-containing precipitate particles observed in the observation view field except for particles having a circle equivalent diameter of less than 0.10 m and particles having a part thereof protruding outside the observation view field are measured for circle equivalent diameter ( ⁇ m), and a value obtained by dividing the sum of the circle equivalent diameters of the measured particles by the total number of the measured particles is designated as the average particle diameter ( ⁇ m) of the Nb-containing precipitate.
  • the total number of the measured particles is 100 or more with plural observation view fields that are randomly selected and do not overlap each other.
  • a circle equivalent diameter of a particle can be calculated from the area of the particle obtained through image processing of the SEM micrograph with an image processing software.
  • the ferritic stainless steel raw material steel sheet for annealing and cold rolling can be produced by a method containing hot-rolling a cast piece, such as a continuous cast slab, including heating the cast piece to a temperature of from 1,000 to 1,150° C., and then extracting.
  • the invention also provides, as a ferritic stainless steel sheet improved in r value and ridging resistance, a ferritic stainless steel cold-rolled and annealed steel sheet having the aforementioned chemical composition, having an existing amount of a Nb-containing precipitate of 0.19% by mass or more, and having a waviness height W defined by the following item (A) of 2.0 ⁇ m or less.
  • the cold-rolled and annealed steel sheet may have a sheet thickness, for example, of from 1.0 to 2.5 mm.
  • a tensile test piece of JIS No. 5 is collected from the steel sheet with the longitudinal direction of the test piece being directed to the rolling direction of the steel sheet; a tensile strain is applied to the tensile test piece until an elongation ratio of a parallel portion of the test piece reaches 20%; then the tensile strain is removed to provide a test piece; a surface profile of the test piece in a center portion in the longitudinal direction is measured in the transverse direction (i.e., the direction perpendicular to the rolling direction); a waviness curve having a wavelength component of from 0.5 to 8.0 mm is determined according to JIS B0601:2013 with cutoff values ⁇ f of 8.0 mm and ⁇ c of 0.5 mm; and an arithmetic average waviness Wa ( ⁇ m) is obtained from the waviness curve, and is designated as the waviness height W.
  • the ferritic stainless steel sheet improved in r value and ridging resistance can be produced by the following production method.
  • a method for producing a ferritic stainless steel cold-rolled and annealed steel sheet containing:
  • hot-rolling a cast piece of a steel having the aforementioned chemical composition including heating the cast piece to a temperature of from 1,000 to 1,150° C., and then extracting, so as to provide a raw material steel sheet (hot-rolled steel sheet) having an existing amount of a Nb-containing precipitate of 0.2% by mass or more;
  • annealing annealing for the hot-rolled sheet
  • a temperature of from 900 to 1,100° C. a temperature of from 900 to 1,100° C.
  • a Nb-containing ferritic stainless steel sheet improved in r value and ridging resistance simultaneously is achieved.
  • the steel sheet is significantly useful for providing a member that is required to have high press workability and excellent surface profile after working.
  • FIG. 1 is an illustration exemplifying a crystallographic orientation map in a 001 inverse pole FIGURE of a cold-rolled and annealed steel sheet of a Nb-containing ferritic stainless steel.
  • the invention targets a ferritic stainless steel containing component elements shown below.
  • the percentages for the chemical composition of the steel sheet are percentages by mass unless otherwise indicated.
  • Nb carbonitride contributes to the formation of a texture advantageous for the enhancement of the r value. Nb carbonitride also suppresses the formation of colonies in the production process of the steel sheet, and contributes to the enhancement of the ridging resistance. For sufficiently providing these functions, the contents thereof are ensured to be 0.004% or more for C and 0.005% or more for N. Too large amounts of C and N may harden the steel, and may be a factor decreasing the toughness of the hot-rolled steel sheet. Too large amounts of C and N may also be a factor excessively decreasing the amount of dissolved Nb, which is effective for the enhancement of the high temperature strength. The contents thereof are restricted to 0.030% or less for C and 0.025% or less for N.
  • the “Nb carbonitride” herein means a compound phase containing Nb bonded to one or both of C and N.
  • Si and Mn are effective as a deoxidizing agent, and in addition have a function enhancing the high temperature oxidation resistance. It is more effective that the contents thereof are ensured to be 0.05% or more for Si and 0.10% or more for Mn. These elements that are contained in large amounts may harden the steel, and may be a factor decreasing the workability and the toughness.
  • the Si content is restricted to 1.50% or less, and is more preferably 1.00% or less.
  • the Mn content is restricted to 1.50% or less.
  • P and S that are contained in large amounts may be a factor of decreasing the corrosion resistance and the like.
  • the P content is allowed to be 0.040% or less, and the S content is allowed to be 0.010% or less.
  • the excessive decrease of P and the excessive decrease of S may be economically disadvantageous due to the increased load in the steel making.
  • the contents thereof may be controlled in a range of from 0.005 to 0.040% for P, and may be controlled in a range of from 0.0005 to 0.010% for S.
  • Ni has a function suppressing the progress of corrosion, and may be added depending on necessity. In this case, it is more effective that the Ni content is ensured to be 0.01% by mass or more.
  • Ni is an element stabilizing an austenite phase, and therefore excessive addition thereof to a ferritic stainless steel may form a martensite phase, and may deteriorate the workability. Excessive addition of Ni may increase the cost.
  • the Ni content is restricted to 2.0% or less.
  • Cr is important for ensuring the corrosion resistance as a stainless steel. Cr is also effective for the enhancement of the high temperature oxidation resistance. For providing these functions, the Cr content is necessarily 12.0% or more. Cr that is contained in a large amount may harden the steel, and may be a factor decreasing the workability. A steel having a Cr content of 25.0% or less is targeted herein. The Cr content may also be managed to 20.0% or less.
  • Mo is an element effective for the enhancement of the corrosion resistance, and may be added depending on necessity. In this case, it is more effective that the Mo content is ensured to be 0.03% or more. However, a large amount thereof added may decrease the hot workability, the workability, and the toughness of the steel, and may lead to increase of the production cost. In the case where Mo is added, the content thereof is necessarily in a range of 3.0% or less.
  • Cu is an element effective for the enhancement of the low temperature toughness and also effective for the enhancement of the high temperature strength. Therefore, Cu may be added depending on necessity. In this case, it is more effective that the Cu content is ensured to be 0.02% or more. However, Cu that is added in a large amount may rather decrease the workability. In the case where Cu is added, the content thereof is necessarily in a range of 2.0% or less.
  • Nb is effective for the increase of the high temperature strength.
  • Nb is an important element for the enhancement of the r value and the ridging resistance through the utilization of the Nb-containing precipitate.
  • the Nb content is necessarily 0.20% or more, and is more preferably 0.30% or more. Nb that is excessively contained may be a factor decreasing the toughness. As a result of the various investigations, the Nb content is restricted to 0.80% or less, and may be managed to 0.60% or less.
  • Al is effective as a deoxidizing agent. For sufficiently providing the function, it is effective to add Al to make an Al content of 0.001% or more. Al that is excessively contained may increase the hardness, and may decrease the workability and the toughness. The Al content is restricted to 0.10% or less.
  • B is effective for the enhancement of the secondary workability, and may be added depending on necessity. In this case, it is more effective that the content thereof is ensured to be 0.0002% or more. However, the B content that exceeds 0.0030% may impair the homogeneity of the metal structure through the formation of Cr 2 B, and the workability may be decreased in some cases. In the case where B is added, the content thereof is in a range of 0.0030% or less.
  • Ti has a function fixing C and N, and is an element effective for retaining the corrosion resistance and the high temperature oxidation resistance of the steel to high levels. Therefore, Ti may be added depending on necessity. For sufficiently providing the functions, it is more effective that the Ti content is ensured to be 0.05% or more. However, Ti that is excessively contained may decrease the toughness and the workability of the steel, and may adversely affect the surface property of the product. In the case where Ti is added, the content thereof is in a range of 0.30% or less.
  • the amount of a Nb-containing precipitate existing in the ferritic stainless steel raw material steel sheet for annealing and cold rolling is significantly important for the enhancement of the r value and the ridging resistance of a cold-rolled and annealed steel sheet that is obtained by applying a processing heat history of annealing, cold rolling, and annealing to the raw material steel sheet.
  • a pinning effect is exhibited by the precipitate, thereby providing a texture having a large amount of crystals with a ⁇ 111 ⁇ crystallographic orientation advantageous for the enhancement of the r value.
  • the strain concentrated around the Nb-containing precipitate facilitates recrystallization in the annealing for the hot-rolled sheet, and the formation of colonies (crystal grain groups having approximate crystallographic orientation) is suppressed.
  • colonies crystal grain groups having approximate crystallographic orientation
  • the r value and the ridging resistance of the final product steel sheet i.e., the cold-rolled and annealed steel sheet
  • the upper limit of the existing amount of the Nb-containing precipitate is restricted by the contents of Nb, C, and N in the steel, and thus may not be particularly limited, and it may be suffices that the existing amount thereof is, for example, 0.50% or less.
  • the heat extraction temperature thereof is from 1,000 to 1,150° C.
  • the dissolution of the Nb-containing precipitate existing in the case piece proceeds to decrease the amount of the Nb-containing precipitate before starting the hot rolling.
  • the heating temperature of the cast piece is less than 1,000° C., the influence of the cast structure largely remains in the metal structure after hot rolling, and colonies tend to form.
  • the retention time of heating to a temperature of from 1,000 to 1,150° C. may be, for example, from 30 to 200 minutes.
  • hot rolling conditions for an ordinary Nb-containing stainless steel sheet may be used.
  • the temperatures in the respective passes of the hot rolling may be from 650 to 1,000° C.
  • the winding temperature may be from 300 to 650° C.
  • the hot-rolled steel sheet having a sheet thickness, for example, of from 3.0 to 6.0 mm is produced in the aforementioned manner, and the hot-rolled steel sheet is used as a ferritic stainless steel raw material steel sheet for annealing and cold rolling.
  • a hot-rolled steel sheet having a Nb-containing precipitate having an average particle diameter of from 2.0 to 10.0 m in terms of circle equivalent diameter can be obtained
  • the aforementioned raw material steel sheet (hot-rolled steel sheet) is subjected to annealing for the hot-rolled sheet at a temperature of from 900 to 1,100° C.
  • the annealing temperature is less than 900° C.
  • the worked (rolled) structure may remain to form an unrecrystallized structure extending in the rolling direction.
  • the improvement of the ridging resistance may be insufficient.
  • the Nb-containing precipitate remaining in a large amount may partly dissolved, and the recrystallized texture advantageous for the enhancement of the r value is difficult to obtain in the subsequent step.
  • the annealing for the hot-rolled sheet may be performed with an ordinary continuous annealing equipment.
  • the annealing time may be, for example, from 0 to 30 seconds in terms of soaking time (i.e., a period of time where the temperature of the material is retained at the prescribed annealing temperature).
  • An oxidized scale is removed by acid pickling or the like from the surface of the steel sheet after completing the annealing for the hot-rolled sheet, which is then subjected to cold rolling.
  • the cold rolling reduction ratio is ensured to be a reduction ratio capable of causing recrystallization in the finish annealing as the next step.
  • a cold rolling reduction ratio of 50% or more may be effective.
  • the upper limit of the cold rolling reduction ratio is restricted by the capability of the equipment, and may be generally set in a range of 90% or less.
  • the sheet thickness after the cold rolling may be, for example, from 1.0 to 2.5 mm.
  • finish annealing is performed.
  • the annealing may be performed under ordinary conditions.
  • the conditions may be set in ranges of a temperature of from 1,000 to 1,100° C. and a soaking time of from 0 to 30 seconds. According to the aforementioned procedures, a cold-rolled and annealed steel sheet that is improved in both r value and ridging resistance can be obtained.
  • the Nb-containing precipitate having existed in the hot-rolled steel sheet exists in a large amount even after subjecting to the cold rolling and the finish annealing.
  • the existing amount of the Nb-containing precipitate is significantly effectively 0.19% by mass or more for the improvement of the r value, and is more preferably 0.20% by mass or more.
  • the upper limit of the Nb-containing precipitate in the cold-rolled and annealed steel sheet is restricted by the contents of Nb, C, and N in the steel as similar to the case of the hot-rolled steel sheet, and thus may not be particularly limited, and it may be suffices that the existing amount thereof is, for example, 0.50% or less.
  • the ridging resistance can be evaluated by the waviness height W defined by the aforementioned item (A).
  • a waviness height W of 2.0 ⁇ m or less can be judged to have excellent ridging resistance as a cold-rolled and annealed steel sheet of the Nb-containing steel having the aforementioned chemical composition.
  • FIG. 1 exemplifies a crystallographic orientation map in a 001 inverse pole FIGURE of a cold-rolled and annealed steel sheet having a sheet thickness of 2.0 mm produced with a cast piece of a Nb-containing ferritic stainless steel having a Nb-content of 0.40% through a process including hot rolling, annealing for the hot-rolled sheet, cold rolling, and finish annealing.
  • the orientation map is obtained for the plane (Z plane) perpendicular to the sheet thickness direction based on data of the crystallographic orientation distribution measured for the cross section (L cross section) in parallel to the rolling direction and the sheet thickness direction by EBSD (electron backscatter diffraction).
  • FIG. 1( a ) shows an ordinary material with a heat extraction temperature of a cast piece before hot rolling of 1,230° C.
  • FIG. 1( b ) shows the material of the invention with a heat extraction temperature thereof of 1,100° C.
  • the other conditions than the heat extraction temperature of a cast piece are common to both the cases.
  • the FIGURE is obtained by converting the original color image to a gray scale image. It is understood from the FIGURE that the ratio of the orientation in the ⁇ 111 ⁇ plane is significantly increased in FIG. 1( b ) where the heat extraction temperature of a cast piece before hot rolling is lowered.
  • the crystallographic orientation is effective for the enhancement of the r value.
  • Steels having the chemical compositions shown in Table 1 were made in an ordinary method to provide cast pieces (continuous cast slabs).
  • the cast pieces each were extracted at the cast piece heating temperature shown in Table 2 for 120 minutes, and then was hot-rolled to provide a hot-rolled steel sheet having a sheet thickness of 4.5 mm.
  • the rolling temperature of the final pass of the hot rolling was in a range of from 650 to 700° C.
  • the winding temperature was in a range of from 500 to 650° C.
  • a specimen was collected from each of the hot-rolled steel sheets, and the existing amount of a Nb-containing precipitate was obtained by the electrolytic extraction method according to “Method for Obtaining Existing Amount of Nb-containing Precipitate” described above.
  • the cross sectional surface (L cross sectional surface) of each of the hot-rolled steel sheets in parallel to the rolling direction and the thickness direction thereof was observed with SEM, S-4000, produced by Hitachi, Ltd., and the average particle diameter of the Nb-containing precipitate was obtained according to “Method for Obtaining Average Particle Diameter of Nb-containing Precipitate” described above.
  • a cold-rolled and annealed steel sheet was produced with the aforementioned hot-rolled steel sheet as a raw material steel sheet.
  • the hot-rolled steel sheet was subjected to annealing for the hot-rolled sheet at the temperature shown in Table 2, and acid pickling in a continuous annealing and acid pickling line.
  • the annealing time was in a range of from 0 to 30 seconds in terms of soaking time.
  • the resulting hot-rolled and annealed steel sheet (sheet thickness: 4.5 mm) was subjected to cold rolling, and thereafter was subjected to finish annealing at a temperature of from 1,000 to 1,100° C.
  • the r value is a value obtained by dividing the true strain in the width direction by the true strain in the thickness direction (JIS G0202:2013, No. 1182).
  • W 0 represents the width (mm) of the parallel portion of the test piece before the tensile test
  • W represents the width (mm) of the parallel portion of the test piece after the tensile test
  • to represents the thickness (mm) of the parallel portion of the test piece before the tensile test
  • t represents the thickness (mm) of the parallel portion of the test piece after the tensile test.
  • test piece of JIS No. 5 (JIS Z2241:2011) was collected from the cold-rolled and annealed steel sheet with the longitudinal direction of the test piece being directed to the rolling direction of the steel sheet, and a tensile strain of 20% was applied to the test piece in the rolling direction, followed by removing the tensile strain, so as to provide a test piece.
  • the surface profile of the test piece in the center portion was measured with a contact surface roughness meter (SURFCOM 2900DX, produced by Tokyo Seimitsu Co., Ltd.) according to the aforementioned item (A), and an arithmetic average waviness Wa was obtained based on the surface profile, and was designated as the waviness height W ( ⁇ m).
  • the steel sheet is evaluated as having excellent ridging resistance even in working to a product with a high working degree. Accordingly, a specimen having a waviness height of 2.0 ⁇ m or less was evaluated as pass (good in ridging resistance), and a specimen having a value exceeding that was evaluated as fail (poor in ridging resistance). The results are shown in Table 2.
  • the hot-rolled steel sheet has a sufficiently large content of the Nb-containing precipitate.
  • the cold-rolled and annealed steel sheet obtained with the hot-rolled steel sheet as a raw material through the procedure performing the suitable annealing for the hot-rolled sheet has a large average r value and a small waviness height. Accordingly, the demands for the improvement of the r value and the ridging resistance for the Nb-containing ferritic stainless steel sheet are simultaneously achieved.
  • the cold-rolled and annealed steel sheet contains the Nb-containing precipitate remaining in a large amount, and thus it is considered that the existing amount of the Nb-containing precipitate is retained to a high level even after subjecting to the annealing for the hot-rolled sheet, which contributes to the formation of the crystallographic orientation advantageous for the enhancement of the r value in the process of cold rolling and finish annealing.
  • the hot-rolled steel sheet having a sufficient content of the Nb-containing precipitate is used, the resulting cold-rolled and annealed steel sheet is deteriorated in ridging resistance due to the low annealing temperature for the hot-rolled sheet.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)
US16/086,086 2016-03-30 2017-03-28 Nb-CONTAINING FERRITIC STAINLESS STEEL SHEET AND MANUFACTURING METHOD THEREFOR Abandoned US20200277690A1 (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2016067079 2016-03-30
JP2016-067079 2016-03-30
PCT/JP2017/012762 WO2017170611A1 (ja) 2016-03-30 2017-03-28 Ｎｂ含有フェライト系ステンレス鋼板およびその製造方法

Publications (1)

Publication Number Publication Date
US20200277690A1 true US20200277690A1 (en) 2020-09-03

Family

ID=59964690

Family Applications (1)

Application Number Title Priority Date Filing Date
US16/086,086 Abandoned US20200277690A1 (en) 2016-03-30 2017-03-28 Nb-CONTAINING FERRITIC STAINLESS STEEL SHEET AND MANUFACTURING METHOD THEREFOR

Country Status (12)

Country Link
US (1) US20200277690A1 (ja)
EP (1) EP3438313A4 (ja)
JP (1) JP6385507B2 (ja)
KR (1) KR20180126064A (ja)
CN (1) CN109072378A (ja)
CA (1) CA3018162C (ja)
MX (1) MX2018011206A (ja)
MY (1) MY188609A (ja)
RU (1) RU2736309C2 (ja)
TW (1) TWI715754B (ja)
WO (1) WO2017170611A1 (ja)
ZA (1) ZA201806778B (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220017984A1 (en) * 2018-12-11 2022-01-20 Jfe Steel Corporation Ferritic stainless steel sheet and method for producing same

Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20190077723A (ko) * 2017-12-26 2019-07-04 주식회사 포스코 오렌지필 저항성과 성형성이 향상된 페라이트계 스테인리스강
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
JP6738928B1 (ja) * 2019-03-29 2020-08-12 日鉄ステンレス株式会社 フェライト系ステンレス鋼板およびその製造方法
JP2020164955A (ja) * 2019-03-29 2020-10-08 日鉄ステンレス株式会社 塗装用フェライト系ステンレス鋼板及び塗装鋼板
CN115917029A (zh) * 2020-10-23 2023-04-04 日铁不锈钢株式会社 铁素体系不锈钢及铁素体系不锈钢的制造方法
CN115287539B (zh) * 2022-08-05 2023-06-30 鞍钢联众(广州)不锈钢有限公司 高温强度良好的汽车排气系统不锈钢板及其制备方法
WO2024070493A1 (ja) * 2022-09-26 2024-04-04 日鉄ステンレス株式会社 電池部品用フェライト系ステンレス鋼材及びその製造方法、並びに電池部品

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58199822A (ja) * 1982-05-15 1983-11-21 Nippon Steel Corp リジングと熱間ロール焼付き疵のないフェライト系ステンレス薄鋼板の製造方法
JP3995822B2 (ja) * 1999-03-05 2007-10-24 日本冶金工業株式会社 耐リジング性に優れた高純度フェライト系ステンレス鋼板の製造方法
ITRM20010584A1 (it) * 2001-09-26 2003-03-26 Acciai Speciali Terni Spa Acciaio inossidabile ferritico e suo uso nella fabbricazione di manufatti per impieghi ad elevate temperature.
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
KR101179408B1 (ko) * 2006-05-09 2012-09-04 닛폰 스틸 앤드 스미킨 스테인레스 스틸 코포레이션 내간극 부식성이 우수한 페라이트계 스테인리스 강
JP5003263B2 (ja) * 2007-04-18 2012-08-15 Ｊｆｅスチール株式会社 オーステナイト系ステンレス鋼板との溶接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
ES2802413T3 (es) * 2007-06-21 2021-01-19 Jfe Steel Corp Chapa de acero inoxidable ferrítico que tiene excelente resistencia a la corrosión frente al ácido sulfúrico, y método para la producción de la misma
US20110061777A1 (en) * 2007-08-20 2011-03-17 Jfe Steel Corporation Ferritic stainless steel sheet having superior punching workability and method for manufacturing the same
JP5262029B2 (ja) * 2007-09-11 2013-08-14 Ｊｆｅスチール株式会社 伸びフランジ加工性に優れたフェライト系ステンレス鋼板
WO2011010746A1 (ja) * 2009-07-23 2011-01-27 Ｊｆｅスチール株式会社 耐食性に優れた燃料電池用ステンレス鋼およびその製造方法
US8440029B2 (en) * 2009-07-30 2013-05-14 Jfe Steel Corporation Stainless steel having good conductivity and ductility for use in fuel cell and method for producing the same
CN103608479B (zh) * 2011-06-16 2016-09-07 新日铁住金不锈钢株式会社 抗皱性优良的铁素体系不锈钢板及其制造方法
JP5837258B2 (ja) * 2013-03-27 2015-12-24 新日鐵住金ステンレス株式会社 研磨後の表面耐食性に優れるフェライト系ステンレス鋼及びその製造方法
CN103741053B (zh) * 2013-12-26 2018-04-10 宝钢不锈钢有限公司 一种具有良好抛光性能的铁素体不锈钢及其制造方法
KR102267129B1 (ko) * 2016-02-02 2021-06-18 닛테츠 스테인레스 가부시키가이샤 Nb함유 페라이트계 스테인리스 열연 강판 및 그 제조 방법과, Nb함유 페라이트계 스테인리스 냉연 강판 및 그 제조 방법

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220017984A1 (en) * 2018-12-11 2022-01-20 Jfe Steel Corporation Ferritic stainless steel sheet and method for producing same

Also Published As

Publication number Publication date
MY188609A (en) 2021-12-22
WO2017170611A1 (ja) 2017-10-05
MX2018011206A (es) 2018-11-22
JP2017186665A (ja) 2017-10-12
TW201741471A (zh) 2017-12-01
CA3018162C (en) 2022-07-05
TWI715754B (zh) 2021-01-11
CA3018162A1 (en) 2017-10-05
EP3438313A4 (en) 2019-08-21
KR20180126064A (ko) 2018-11-26
RU2736309C2 (ru) 2020-11-13
ZA201806778B (en) 2020-01-29
JP6385507B2 (ja) 2018-09-05
RU2018137478A (ru) 2020-04-30
CN109072378A (zh) 2018-12-21
RU2018137478A3 (ja) 2020-06-10
EP3438313A1 (en) 2019-02-06

Similar Documents

Publication Publication Date Title
US20200277690A1 (en) Nb-CONTAINING FERRITIC STAINLESS STEEL SHEET AND MANUFACTURING METHOD THEREFOR
JP6226955B2 (ja) 時効熱処理後の強度増加が小さいフェライト系ステンレス鋼板及びその製造方法
CN109072371B (zh) 温加工用高强度钢板及其制造方法
WO2017026125A1 (ja) 高強度鋼板用素材、高強度鋼板用熱延材、高強度鋼板用熱延焼鈍材、高強度鋼板、高強度溶融めっき鋼板および高強度電気めっき鋼板と、これらの製造方法
US10550454B2 (en) Cold-rolled ferritic stainless steel sheet
JP6176326B2 (ja) 冷延鋼板、亜鉛めっき冷延鋼板及びそれらの製造方法
JP6137434B1 (ja) オーステナイト系ステンレス鋼
JP2010265545A (ja) 時効性および焼付け硬化性に優れた冷延鋼板およびその製造方法
JP5907320B1 (ja) ステンレス冷延鋼板用素材およびその製造方法
JP2019014933A (ja) 鋼板およびその製造方法
US10626486B2 (en) Stainless steel and production method therefor
JP2019039037A (ja) 鋼板およびその製造方法
JP5217617B2 (ja) フェライト系ステンレス冷延鋼板およびその製造方法
JP5045050B2 (ja) 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
US20170002436A1 (en) Ferritic lightweight steel sheet having excellent strength and ductility and method for manufacturing the same
JP6042265B2 (ja) 降伏強度と成形性に優れた高強度冷延鋼板およびその製造方法
JP5534112B2 (ja) 冷間圧延の素材用の熱延鋼板およびその製造方法
JP5045051B2 (ja) 冷延用フェライト系ステンレス熱延鋼板およびその製造方法
JP5644148B2 (ja) 加工後の表面外観に優れたステンレス冷延鋼板およびその製造方法
KR20190077672A (ko) 리징성이 우수한 페라이트계 스테인리스강
JP2010095742A (ja) 強度−伸びバランスが良好で、かつリジングの小さいステンレス冷延鋼板およびその製造方法
JP2018115351A (ja) 高ヤング率極薄鋼鈑及びその製造方法

Legal Events

Date Code Title Description
AS Assignment

Owner name: NISSHIN STEEL CO., LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:YAKUSHIJIN, YUTAKA;HIRONAKA, AKIRA;IMAKAWA, KAZUNARI;REEL/FRAME:047335/0055

Effective date: 20181016

AS Assignment

Owner name: NIPPON STEEL NISSHIN CO., LTD., JAPAN

Free format text: CHANGE OF NAME;ASSIGNOR:NISSHIN STEEL CO., LTD.;REEL/FRAME:049124/0373

Effective date: 20190411

AS Assignment

Owner name: NIPPON STEEL STAINLESS STEEL CORPORATION, JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NIPPON STEEL NISSHIN CO., LTD.;REEL/FRAME:051852/0615

Effective date: 20200109

STPP Information on status: patent application and granting procedure in general

Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION