WO2018116792A1 - Acier inoxydable ferritique - Google Patents

Acier inoxydable ferritique Download PDF

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WO2018116792A1
WO2018116792A1 PCT/JP2017/043381 JP2017043381W WO2018116792A1 WO 2018116792 A1 WO2018116792 A1 WO 2018116792A1 JP 2017043381 W JP2017043381 W JP 2017043381W WO 2018116792 A1 WO2018116792 A1 WO 2018116792A1
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thermal fatigue
stainless steel
steel
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Japanese (ja)
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徹之 中村
石川　伸
杉原　玲子
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Ｊｆｅスチール株式会社
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Priority to MX2019007483A priority Critical patent/MX2019007483A/es
Priority to JP2018529681A priority patent/JP6665936B2/ja
Priority to KR1020217015167A priority patent/KR102400403B1/ko
Priority to EP17883821.5A priority patent/EP3517647A4/fr
Priority to CN201780079113.7A priority patent/CN110088324A/zh
Priority to KR1020197016818A priority patent/KR20190085029A/ko
Priority to US16/470,343 priority patent/US20190316236A1/en
Publication of WO2018116792A1 publication Critical patent/WO2018116792A1/fr

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    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
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    • 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
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/02—Hardening by precipitation
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    • 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
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    • 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
    • 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
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
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    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • 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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    • 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%
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    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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    • 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
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    • 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
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    • 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
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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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
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
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    • 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
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    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
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    • 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

Definitions

  • the present invention relates to a ferritic stainless steel having excellent scale adhesion, thermal fatigue characteristics and condensed water corrosion resistance.
  • the exhaust manifold which is directly connected to the engine, especially in the upstream side, is used in harsh environments where the maximum operating temperature reaches 800-900 ° C. Therefore, excellent thermal fatigue characteristics are required for the material, and ferritic stainless steel added with Nb is mainly used.
  • Nb added to ferritic stainless steel increases the high temperature strength and improves thermal fatigue properties by dissolving in the steel.
  • Nb is likely to combine with C and N in the steel to become carbonitride, and the amount of solid solution Nb may be reduced to deteriorate the thermal fatigue characteristics.
  • a typical example of this Nb-Ti composite added steel is Type 441 ferritic stainless steel (18% Cr-0.5% Nb-0.2% Ti) (EN10088-2: EN1.4509). Widely used in automobile exhaust manifolds.
  • the exhaust manifold Since the exhaust manifold is used in a severe and repeated oxidation environment that is repeatedly heated and cooled each time the engine is started and stopped, if the scale peels off, the iron will be directly exposed to high-temperature exhaust gas and oxidation will proceed. As a result, the plate thickness decreases, and in some cases, holes are formed or deformed. For this reason, the Nb—Ti composite-added ferritic stainless steel used for the exhaust manifold of automobiles is also required to have excellent scale adhesion that prevents the scale from peeling off.
  • Patent Documents 1 and 2 disclose the addition of Mo as a method for improving the high temperature strength and thermal fatigue characteristics of Nb—Ti composite added ferritic stainless steel.
  • Patent Documents 3 to 5 disclose the addition of Mo, Cu, and W.
  • Patent Document 3 discloses the addition of REM, Ca, Y, and Zr.
  • Patent Document 5 discloses the addition of REM and Ca.
  • Patent Document 6 discloses an Nb—Ti composite-added ferritic stainless steel in which scale adhesion and thermal fatigue characteristics are improved by adding Co and Ni.
  • mufflers and pipes arranged downstream of automobile exhaust pipe components for example, water containing snow melting salt scattered on the road, or condensed water containing corrosive ions generated by exhaust gas cooling. Therefore, corrosion resistance (hereinafter referred to as “condensed water corrosion resistance”) is often required, and ferritic stainless steel to which Ti or Mo is added is used. Examples include SUS436L (18% Cr-0.2% Ti-1% Mo) and SUS430LX (18% Cr-0.2% Ti) specified in JIS G4305.
  • the required characteristics of the upstream exhaust manifold and the downstream muffler are different, so ferritic stainless steel suitable for each application has been used, but this is a common ferritic stainless steel. If it can be manufactured, the number of steel types can be reduced, the number of parts where parts of different materials are welded is reduced, the manufacturability of the parts is stabilized, and the automobile manufacturing can be made more efficient.
  • Patent Documents 1 to 5 have disadvantages that Mo and W are expensive and that workability such as toughness of a steel sheet is lowered.
  • Cu has the disadvantage of not only greatly reducing processability at room temperature but also reducing oxidation resistance.
  • Patent Documents 1 to 5 none of the thermal fatigue characteristics and oxidation resistance (scale adhesion) necessary for the exhaust manifold are evaluated simultaneously with the condensate corrosion resistance necessary for the muffler and the like.
  • SUS436L 18% Cr-0.2% Ti-1% Mo
  • SUS430LX 18% Cr-0.2% Ti
  • the present invention has been made to solve the above-described problems, and an object of the present invention is to provide a ferritic stainless steel having excellent scale adhesion and thermal fatigue characteristics and excellent resistance to condensed water corrosion.
  • excellent in scale adhesion means that the polished cold-rolled annealed plate is repeatedly subjected to a repeated oxidation test (heating rate: 100 ° C. for 20 minutes at 1000 ° C. and 1 minute at 100 ° C. for 400 cycles). (5 ° C./sec, cooling rate: 1.5 ° C./sec) indicates that the area where the scale peels on the surface of the test piece after less than 5%.
  • “excellent thermal fatigue characteristics” means that in accordance with JSMS-SD-7-03, heating and cooling are repeated between 200 ° C. and 900 ° C., and at the same time, strain is repeatedly applied at a constraint ratio of 0.6.
  • “Excellent resistance to condensed water corrosion” means holding a cold-rolled annealed plate in a constant temperature bath containing Cl ⁇ : 500 ppm, SO 4 2 ⁇ : 1000 ppm, pH: 4 and temperature: 80 ° C. 1 set: 30 sets of solution immersion 2 hours and drying 6 hours are performed, and the corrosion weight loss is 10 g / m 2 or less.
  • the present inventors examined the effect of the amount of C + N on the thermal fatigue properties of Nb—Ti—Co—Ni composite-added ferritic stainless steel, and made the C + N amount and Ti amount appropriate for steels containing Ti. It has been found that more excellent thermal fatigue characteristics can be obtained by limiting.
  • research on the condensation water corrosion resistance of ferritic stainless steel with Nb-Ti-Co-Ni composite addition was carried out, and by adding appropriate amounts of both Mo and Cu, the condensation water corrosion resistance was improved and downstream of mufflers, etc. It has been found that it can be used for side parts.
  • the present invention has been made based on the above findings, and the gist thereof is as follows.
  • C 0.010% or less
  • Si 1.0% or less
  • Mn 1.0% or less
  • P 0.040% or less
  • S 0.030% or less
  • Cr 17 0.0% or more and 18.5% or less
  • N 0.015% or less
  • Nb 0.40% or more and 0.80% or less
  • Ti 0.10% or more and 0.40% or less
  • Al 0.20%
  • Co 0.01% to 0.30%
  • Mo 0.02% to 0.30%
  • Cu 0.02% to 0.30%.
  • C% and N% represent C and N contents (% by mass), respectively.
  • Ca 0.0005% to 0.0030%
  • Mg 0.0002% to 0.0020%
  • B 0.0002% to 0.0020%
  • a ferritic stainless steel having excellent scale adhesion, thermal fatigue characteristics and condensed water corrosion resistance can be obtained. Since the ferritic stainless steel of the present invention is excellent in both heat resistance (scale adhesion, thermal fatigue characteristics) and condensate corrosion resistance, it should be used suitably both upstream and downstream of automobile exhaust system members. Can do.
  • FIG. 1 is a diagram for explaining a thermal fatigue test piece.
  • FIG. 2 is a diagram for explaining temperature and restraint conditions in a thermal fatigue test.
  • the ferritic stainless steel of the present invention is, in mass%, C: 0.010% or less, Si: 1.0% or less, Mn: 1.0% or less, P: 0.040% or less, S: 0.030.
  • C% + N% 0.018% or less (1)
  • C% and N% represent C and N contents (% by mass), respectively.
  • C 0.010% or less
  • C is an element effective for increasing the strength of steel, and the effect is obtained by containing 0.001% or more of C. Therefore, the C content is 0.001% or more. Preferably there is.
  • the C content is from the viewpoint of ensuring toughness and workability, and the amount of solid solution Nb in the steel decreases and thermal fatigue characteristics deteriorate due to the coarsening of NbC and the increase in the amount of precipitation. Therefore, it is desirable that the content be less, and the C content is preferably 0.008% or less.
  • the C content is more preferably 0.005% or more.
  • Si 1.0% or less
  • Si is an element effective for improving the oxidation resistance, and the effect can be obtained by containing 0.01% or more of Si. Therefore, the Si content is 0.01% or more. Preferably there is.
  • the Si content is more preferably 0.20% or more, and even more preferably 0.30% or more.
  • the Ni content is 0.20% or more and the Si content is 0.30% or more, the scale adhesion is particularly excellent.
  • Si content becomes like this.
  • it is 1.00% or less, More preferably, it is 0.50% or less, More preferably, it is 0.40% or less.
  • Mn 1.0% or less
  • Mn is an element that increases the strength of steel and also has an action as a deoxidizer. Since the effect can be obtained with a Mn content of 0.01% or more, the Mn content is preferably 0.01% or more. On the other hand, if Mn is contained exceeding 1.0%, the oxidation increase is remarkably increased and the oxidation resistance is lowered, so the Mn content is 1.0% or less.
  • the Mn content is more preferably 0.20% or more, and even more preferably 0.30% or more. Moreover, Mn content becomes like this. Preferably it is 1.00% or less, More preferably, it is 0.60% or less, More preferably, it is 0.50% or less.
  • P 0.040% or less
  • P is an element that lowers toughness, and is desirably reduced.
  • the P content is 0.040% or less.
  • the P content is 0.035% or less. More preferably, the P content is 0.030% or less.
  • S 0.030% or less Since S decreases moldability and corrosion resistance, it is preferable that S be less.
  • the S content is 0.030% or less.
  • the S content is 0.006% or less. More preferably, the S content is 0.003% or less.
  • Cr 17.0% or more and 18.5% or less Cr is an element necessary for improving corrosion resistance and oxidation resistance. In order to obtain good corrosion resistance and oxidation resistance, 17.0% or more of Cr It is necessary to contain. If the Cr content is less than 17.0%, the oxide scale tends to increase, and not only the adhesion to the scale is lowered, but also the thermal fatigue characteristics may be lowered. Furthermore, sufficient corrosion resistance in condensed water cannot be obtained. On the other hand, if the Cr content exceeds 18.5%, the steel becomes hard and manufacturability and workability deteriorate, so the Cr content is set to 18.5% or less. Preferably, the Cr content is in the range of 17.5% to 18.5%.
  • N 0.015% or less N is preferable because it lowers the toughness and workability of the steel.
  • the N content is high, coarse TiN precipitates, and a large amount of NbC precipitates accompanying TiN. As a result, the amount of solute Nb in the steel is reduced, so that the thermal fatigue characteristics are lowered.
  • the N content is set to 0.015% or less.
  • the N content is 0.012% or less. More preferably, the N content is 0.010% or less.
  • Nb 0.40% or more and 0.80% or less
  • Nb is an element having an effect of improving thermal fatigue properties by solid solution in steel and remarkably increasing high-temperature strength. The effect is obtained when Nb content is 0.40% or more.
  • excessive Nb content exceeding 0.80% not only lowers the toughness of the steel, but also forms a Laves phase (Fe 2 Nb) at a high temperature and lowers the high temperature strength, so the Nb content is 0 80% or less.
  • the Nb content is preferably 0.43% or more, and more preferably 0.45% or more.
  • Nb content becomes like this. Preferably it is 0.60% or less, More preferably, it is 0.50% or less.
  • Ti 0.10% or more and 0.40% or less Ti is preferentially combined with C and N to generate carbonitride, thereby preventing the formation of Nb carbonitride, and corrosion resistance, formability, and welded portion. Improves intergranular corrosion resistance. In order to obtain these effects, it is necessary to contain 0.10% or more of Ti. If the Ti content is less than 0.10%, C and N cannot be produced completely as Ti carbonitride, Nb carbonitride is formed, and the Nb solid solution amount is reduced, resulting in thermal fatigue characteristics. Decreases.
  • Ti content shall be 0.40% or less.
  • the Ti content is preferably 0.15% or more. Moreover, Ti content becomes like this. Preferably it is 0.30% or less, More preferably, it is 0.25% or less.
  • Al 0.20% or less Since Al is an element effective for deoxidation, and the effect is obtained with a content of 0.01% or more, the Al content is preferably 0.01% or more. On the other hand, in order to harden steel and reduce workability, the Al content is set to 0.20% or less. The Al content is more preferably 0.02% or more. Moreover, Al content becomes like this. Preferably it is 0.10% or less, More preferably, it is 0.06% or less.
  • Ni 0.05% or more and 0.40% or less
  • Ni is an important element for securing scale adhesion in the present invention.
  • Ni is contained at 0.05% or more. It is necessary. When Ni is less than 0.05%, the adhesion of the scale is lowered, and the point at which the scale is peeled off may cause thermal fatigue failure. Further, as will be described later, since the thermal expansion coefficient of the steel of the present invention is reduced by containing an appropriate amount of Co, the Ni content is smaller than that of steel containing no Co or steel lacking the Co content. The above effect can be obtained.
  • the Ni content is in the range of 0.05% to 0.40%.
  • the Ni content is preferably 0.10% or more, more preferably 0.20% or more.
  • Ni content becomes like this. Preferably it is 0.30% or less, More preferably, it is 0.25% or less.
  • Co 0.01% or more and 0.30% or less
  • Co is an important element in the present invention.
  • Co is an element necessary for improving thermal fatigue characteristics, and for that purpose, it is necessary to contain at least 0.01% of Co.
  • Co can improve thermal fatigue characteristics by reducing the thermal expansion coefficient of steel to reduce the amount of expansion at the time of temperature rise and by reducing the amount of strain generated at the time of temperature rise and cooling. Furthermore, when the thermal expansion coefficient of steel is reduced, the difference between the thermal expansion coefficients of steel and scale is reduced, and the scale is difficult to peel off during cooling. Therefore, there is an effect that peeling of the scale can be prevented by containing a smaller amount of Ni.
  • the Co content is 0.01% or more and 0.30% or less.
  • the Co content is preferably 0.02% or more, and more preferably 0.03% or more. Further, the Co content is preferably 0.10% or less.
  • Mo 0.02% or more and 0.30% or less Mo increases the strength of steel by solid solution strengthening to improve thermal fatigue properties and improve corrosion resistance against salt water by improving salt corrosion resistance It is an element, and the effect is obtained when the Mo content is 0.02% or more. However, Mo is an expensive element. When a large amount of Mo is contained, not only surface defects are generated, but workability at room temperature is lowered. In order to obtain good surface properties without generating surface defects, the Mo content needs to be 0.30% or less. Therefore, the Mo content is in the range of 0.02% to 0.30%. The Mo content is preferably 0.04% or more. Further, the Mo content is preferably 0.10% or less.
  • Cu 0.02% or more and 0.40% or less
  • Cu precipitates finely as ⁇ -Cu, strengthens the steel to improve thermal fatigue characteristics, and improves sulfuric acid corrosion resistance to condensate water Has the effect of improving corrosivity.
  • it is necessary to contain 0.02% or more of Cu.
  • Cu content shall be 0.40% or less. Therefore, the Cu content is in the range of 0.02% to 0.40%.
  • the Cu content is preferably 0.04% or more. Further, the Cu content is preferably 0.10% or less.
  • Mo and Cu improve condensation water corrosion resistance by improving salt corrosion corrosion resistance and sulfuric acid corrosion resistance, respectively. Therefore, the inclusion of Mo or Cu alone is sufficient. Cannot be obtained. In the present invention, excellent resistance to condensed water corrosion can be obtained because it contains both Mo and Cu in appropriate amounts.
  • C% + N% 0.018% or less
  • C% and N% represent C and N contents (% by mass), respectively.
  • the contents of C and N are 0.010% or less and 0.015% or less from the viewpoints of toughness, workability, and scale peel resistance.
  • C% + N% is limited to 0.018% or less as in the above formula (1).
  • C% + N% exceeds 0.018%, a large amount of coarse Ti nitride (TiN) is generated, and NbC precipitates around TiN concomitantly, so that the amount of NbC deposited increases.
  • C% + N% is set to 0.018% or less in order to sufficiently obtain the solid solution strengthening amount of Nb.
  • C% + N% is 0.015% or less.
  • the precipitated TiN and NbC become finer, and further, the amount of NbC precipitated around the TiN is reduced, so that the solid solution in the steel is reduced. Nb amount increases.
  • the precipitation strengthening effect is also obtained by the fine precipitation of NbC itself. These effects improve thermal fatigue characteristics. More preferably, C% + N% is 0.013% or less.
  • the present invention is a ferritic stainless steel which contains the above-mentioned essential components and the balance consists of Fe and inevitable impurities, and is excellent in scale adhesion and thermal fatigue properties and also in anti-condensation water corrosion resistance. is there. Furthermore, if necessary, one or more selected from Ca, Mg and B, and / or one or more selected from V, W and Zr are within the following ranges. Can be contained.
  • Ca 0.0005% or more and 0.0030% or less
  • Ca is an effective component for preventing nozzle clogging due to precipitation of Ti-based inclusions that are likely to occur during continuous casting. The effect is obtained when the Ca content is 0.0005% or more.
  • the Ca content is preferably 0.0030% or less. Therefore, when Ca is contained, the Ca content is preferably in the range of 0.0005% to 0.0030%. More preferably, the Ca content is in the range of 0.0005% to 0.0020%. More preferably, the Ca content is in the range of 0.0005% to 0.0015%.
  • Mg 0.0002% to 0.0020%
  • Mg is an element effective for improving workability and toughness. Furthermore, Mg is an effective element for suppressing the coarsening of Nb and Ti carbonitrides. When the Ti carbonitride becomes coarse, it becomes a starting point for brittle cracks, so that toughness decreases. Further, when the Nb carbonitride is coarsened, the amount of Nb solid solution in the steel is reduced, which leads to a decrease in thermal fatigue characteristics. The effects of improving the workability and toughness and suppressing the coarsening of Nb and Ti carbonitrides can be obtained with a Mg content of 0.0002% or more.
  • the Mg content exceeds 0.0020%, the surface properties of the steel may be deteriorated. Therefore, when it contains Mg, it is preferable to make Mg content into the range of 0.0002% or more and 0.0020% or less.
  • the Mg content is more preferably 0.0004% or more. Further, the Mg content is more preferably 0.0015% or less, and even more preferably 0.0010% or less.
  • B 0.0002% or more and 0.0020% or less B is an element effective for improving workability, particularly secondary workability. These effects can be obtained with a B content of 0.0002% or more. On the other hand, if the content of B exceeds 0.0020%, the workability and toughness of the steel may decrease, so the B content is set to 0.0020% or less. Therefore, when it contains B, it is preferable to make B content into 0.0002% or more and 0.0020% or less of range. The B content is more preferably 0.0003% or more. Further, the B content is more preferably 0.0010% or less.
  • V 0.01% or more and 0.50% or less
  • V is an element effective for improving high-temperature strength. Moreover, it has the effect which suppresses that the carbonitride of Ti and Nb coarsens. The effect is obtained with a V content of 0.01% or more.
  • coarse V C, N
  • the V content is preferably in the range of 0.01% to 0.50%.
  • the V content is more preferably 0.02% or more. Further, the V content is more preferably 0.20% or less.
  • W 0.02% or more and 0.30% or less
  • W is an element that increases the strength of steel by solid solution strengthening, and the effect is obtained by containing 0.02% or more of W. It is done.
  • W is an expensive element. If a large amount of W is contained, not only surface defects are generated, but workability such as toughness is greatly reduced.
  • the W content is preferably 0.30% or less. Therefore, when it contains W, it is preferable to make W content into the range of 0.02% or more and 0.30% or less.
  • Zr 0.005% to 0.50%
  • Zr is an element that improves oxidation resistance.
  • the Zr content is preferably 0.005% or more.
  • the Zr content exceeds 0.50%, the Zr intermetallic compound is precipitated, and the steel is easily embrittled. Therefore, when Zr is contained, the Zr content is preferably 0.005% or more and 0.50% or less.
  • an ordinary method for producing stainless steel can be used.
  • Steel with the above composition is melted in a melting furnace such as a converter or electric furnace, and further subjected to secondary refining such as ladle refining, vacuum refining, etc., and then a steel slab by continuous casting or ingot-bundling rolling (Slab), hot-rolled, hot-rolled sheet annealed and pickled to give a hot-rolled annealed pickled sheet.
  • a method of forming a cold-rolled annealed plate through each process such as cold rolling, finish annealing, pickling and the like is recommended.
  • An example is as follows.
  • This hot-rolled annealed pickling plate can be used as it is for the applications targeted by the present invention, such as exhaust manifolds, flanges, pipes, and mufflers, but it is further subjected to cold rolling and annealing / pickling.
  • An annealed pickling plate can also be used.
  • two or more cold rolling processes including intermediate annealing may be performed as necessary.
  • the total rolling reduction in the cold rolling process comprising one or more cold rollings is 60% or more, preferably 70% or more.
  • the cold-rolled sheet annealing temperature is 900 to 1150 ° C, preferably 950 to 1100 ° C.
  • the shape and quality of the steel sheet can be adjusted by adding mild rolling (skin pass rolling or the like) after pickling. Moreover, it can also be set to BA finishing which annealed in the reducing atmosphere containing hydrogen and abbreviated the pickling.
  • the hot-rolled annealed sheet product or cold-rolled annealed sheet product obtained in this way is subjected to bending processing according to each application, and the exhaust pipe, catalyst outer cylinder material, and thermal power plant for automobiles and motorcycles. It is formed into an exhaust duct or a fuel cell related member.
  • the welding method for welding these members is not particularly limited, and various arc welding methods such as TIG, MIG, and MAG, resistance welding methods such as spot welding and seam welding, and electric resistance welding methods, etc. High frequency resistance welding and high frequency induction welding can be applied.
  • the sheet bar was heated to 1050 ° C. and hot-rolled to obtain a hot-rolled sheet having a thickness of 5 mm. Thereafter, hot-rolled sheet annealing was performed in a temperature range of 900 to 1050 ° C. and pickled to produce a hot-rolled annealed pickled sheet. At this stage, the surface properties of the steel sheet were observed with the naked eye. This was cold-rolled to a thickness of 2 mm and finish-annealed in a temperature range of 900 to 1050 ° C. to obtain a cold-rolled annealed plate. This was subjected to the following repeated oxidation test and condensed water immersion test.
  • the test piece for thermal fatigue test was repeatedly heated and cooled between 200 ° C. and 900 ° C., and at the same time, strain was repeatedly applied at a restraint ratio of 0.6 as shown in FIG. 2, and the thermal fatigue life was measured.
  • the measurement method was in accordance with the Japan Society of Materials Standard High Temperature Low Cycle Test Method (JSMS-SD-7-03). First, the load detected at 200 ° C. in each cycle was divided by the cross-sectional area (50.3 mm 2 ) of the test piece soaking parallel portion shown in FIG. The number of cycles in which the stress in the cycle was reduced to 75% with respect to the stress in the fifth cycle where the behavior was stable was defined as the thermal fatigue life. Thermal fatigue characteristics were evaluated based on the number of life cycles. The obtained results are also shown in Table 1.
  • constraint rate ⁇ a / (a + b), a is (free thermal expansion strain amount ⁇ control strain amount) / 2, and b is control strain amount / 2. is there.
  • the free thermal expansion strain amount is a strain amount when the temperature is raised without applying any mechanical stress
  • the control strain amount is a strain amount with respect to a state where no stress is applied at room temperature.
  • a substantial restraint strain amount generated in the material by restraint is (free thermal expansion strain amount ⁇ control strain amount), that is, a strain amount with respect to the free thermal expansion strain amount.
  • ⁇ Condensed water immersion test> The cold-rolled annealed plate produced above was cut into a dimension of 60 mm width ⁇ 80 mm length, and all six surfaces were polished with # 320 emery paper and used for the test. During the test, the edge was covered with a protective tape.
  • the test solution simulates condensed water, contains Cl ⁇ : 500 ppm, SO 4 2 ⁇ : 1000 ppm, and is adjusted to pH: 4. The temperature was kept in a thermostat so that the temperature would be 80 ° C. The test was performed for 30 sets, with 2 hours of solution immersion and 6 hours of drying as one set. After the test, the corrosion products were removed, and the weight loss before and after the test was measured to calculate the corrosion weight loss.
  • Comparative Example No. C + N exceeds the upper limit of the scope of the present invention. No. 25 failed in thermal fatigue characteristics. In Comparative Example No. Co in which Co is less than the lower limit of the range of the present invention. No. 26 failed in thermal fatigue characteristics. Comparative Example No. Ni in which Ni is less than the lower limit of the range of the present invention. No. 27 failed in scale adhesion and thermal fatigue characteristics.
  • the ferritic stainless steel sheet of the present invention is excellent in all of scale adhesion, thermal fatigue characteristics, and resistance to condensed water corrosion.
  • it is also possible to configure all the exhaust pipe parts with one steel type, and it is possible to increase the efficiency in terms of the availability of steel and the weldability.
  • it is also suitable as an exhaust system member or a fuel cell member of a thermal power generation system.

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  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
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  • Crystallography & Structural Chemistry (AREA)
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Abstract

L'invention concerne une tôle d'acier inoxydable ferritique qui présente d'excellentes caractéristiques d'adhérence de couche d'oxyde et de fatigue thermique, tout en présentant une excellente résistance à la corrosion par l'eau condensée. Cette tôle d'acier inoxydable ferritique est conçue pour avoir une composition qui contient, en % en masse, 0,010 % ou moins de C, 1,0 % ou moins de Si, 1,0 % ou moins de Mn, 0,040 % ou moins de P, 0,030 % ou moins de S, de 17,0 % à 18,5 % (inclus) de Cr, 0,015 % ou moins de N, de 0,40 % à 0,80 % (inclus) de Nb, de 0,10 % à 0,40 % (inclus) de Ti, 0,20 % ou moins d'Al, de 0,05 % à 0,40 % (inclus) de Ni, de 0,01 % à 0,30 % (inclus) de Co, de 0,02 % à 0,30 % (inclus) de Mo et de 0,02 % à 0,40 % (inclus) de Cu, le reste étant constitué de Fe et d'impuretés inévitables, tout en satisfaisant la formule suivante (1). C% + N% ≤ 0,018 % (1) Dans la formule (1), C% et N% représentent respectivement la teneur (% en masse) de C et la teneur (% en masse) de N.
PCT/JP2017/043381 2016-12-21 2017-12-04 Acier inoxydable ferritique WO2018116792A1 (fr)

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MX2019007483A MX2019007483A (es) 2016-12-21 2017-12-04 Acero inoxidable ferritico.
JP2018529681A JP6665936B2 (ja) 2016-12-21 2017-12-04 フェライト系ステンレス鋼
KR1020217015167A KR102400403B1 (ko) 2016-12-21 2017-12-04 페라이트계 스테인리스 강
EP17883821.5A EP3517647A4 (fr) 2016-12-21 2017-12-04 Acier inoxydable ferritique
CN201780079113.7A CN110088324A (zh) 2016-12-21 2017-12-04 铁素体系不锈钢
KR1020197016818A KR20190085029A (ko) 2016-12-21 2017-12-04 페라이트계 스테인리스 강
US16/470,343 US20190316236A1 (en) 2016-12-21 2017-12-04 Ferritic stainless steel

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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS555570B2 (fr) 1975-07-26 1980-02-07
JPH04224657A (ja) 1990-12-26 1992-08-13 Kawasaki Steel Corp 高温強度と溶接熱影響部の靱性に優れたフェライト系ステンレス鋼
JPH0570897A (ja) 1991-09-13 1993-03-23 Kawasaki Steel Corp 高靱性高温高強度フエライト系ステンレス鋼
JP2004218013A (ja) 2003-01-15 2004-08-05 Sumitomo Metal Ind Ltd 自動車排気系機器用フェライト系ステンレス鋼
JP2008240143A (ja) 2007-02-26 2008-10-09 Nippon Steel & Sumikin Stainless Steel Corp 耐熱性に優れたフェライト系ステンレス鋼板
JP2009174040A (ja) 2008-01-28 2009-08-06 Nisshin Steel Co Ltd Ｅｇｒクーラー用フェライト系ステンレス鋼およびｅｇｒクーラー
JP2013209726A (ja) * 2012-03-30 2013-10-10 Nippon Steel & Sumikin Stainless Steel Corp 加工性に優れた耐熱フェライト系ステンレス冷延鋼板、冷延素材用フェライト系ステンレス熱延鋼板及びそれらの製造方法
WO2013179616A1 (fr) * 2012-05-28 2013-12-05 Ｊｆｅスチール株式会社 Acier inoxydable ferritique
JP2014145097A (ja) * 2013-01-28 2014-08-14 Nippon Steel & Sumikin Stainless Steel Corp 高温プレス成形に適する自動車排気系部材用のフェライト系ステンレス鋼板およびフェライト系ステンレス鋼成形部品の製造方法
JP2015532681A (ja) * 2012-09-03 2015-11-12 アペラム・ステンレス・フランス フェライト系ステンレス鋼板、その製造方法、および特に排気管での使用
US20150345361A1 (en) * 2012-12-24 2015-12-03 Posco Ferritic Stainless Steel for Automotive Exhaust System, Which Have Excellent Corrosion Resistance Against Condensate, Moldability, and High-Temperature Oxidation Resistance, and Method for Manufacturing Same
JP2016204714A (ja) * 2015-04-24 2016-12-08 新日鐵住金ステンレス株式会社 自動車排気系部品締結部品用ステンレス鋼

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0219447A (ja) * 1988-07-05 1990-01-23 Toshiba Corp フェライト系ステンレス鋼
EP1818421A1 (fr) * 2006-02-08 2007-08-15 UGINE & ALZ FRANCE Acier inoxydable ferritique dit à 19% de chrome stabilisé au niobium
JP5152387B2 (ja) * 2010-10-14 2013-02-27 Ｊｆｅスチール株式会社 耐熱性と加工性に優れるフェライト系ステンレス鋼
JP5609571B2 (ja) * 2010-11-11 2014-10-22 Ｊｆｅスチール株式会社 耐酸化性に優れたフェライト系ステンレス鋼
JP6363084B2 (ja) * 2013-09-13 2018-07-25 新日鐵住金ステンレス株式会社 廉価で塩害耐食性に優れた自動車用部材の製造方法、自動車用部材、給油管の製造方法および給油管
JP6075349B2 (ja) * 2013-10-08 2017-02-08 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼
WO2015099459A1 (fr) * 2013-12-24 2015-07-02 (주)포스코 Acier inoxydable ferritique présentant des propriétés améliorées de formabilité et de résistance au striage, et son procédé de production
JP6598478B2 (ja) * 2015-03-12 2019-10-30 日鉄ステンレス株式会社 塩害耐食性に優れかつ外観劣化を抑制した自動車用給油管
US20190106775A1 (en) * 2016-03-29 2019-04-11 Jfe Steel Corporation Ferritic stainless steel sheet
CA3026612A1 (fr) * 2016-06-10 2017-12-14 Jfe Steel Corporation Tole d'acier inoxydable pour separateurs de pile a combustible, et son procede de production
US10763517B2 (en) * 2016-06-10 2020-09-01 Jfe Steel Corporation Stainless steel sheet for fuel cell separators, and production method therefor
JP6699670B2 (ja) * 2016-09-02 2020-05-27 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼
JP6418338B2 (ja) * 2016-09-02 2018-11-07 Ｊｆｅスチール株式会社 フェライト系ステンレス鋼
KR102179607B1 (ko) * 2016-09-12 2020-11-17 제이에프이 스틸 가부시키가이샤 클래드 용접관 및 그 제조 방법
US20200002779A1 (en) * 2017-01-26 2020-01-02 Jfe Steel Corporation Hot-rolled ferritic stainless steel sheet and method for manufacturing same

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS555570B2 (fr) 1975-07-26 1980-02-07
JPH04224657A (ja) 1990-12-26 1992-08-13 Kawasaki Steel Corp 高温強度と溶接熱影響部の靱性に優れたフェライト系ステンレス鋼
JPH0570897A (ja) 1991-09-13 1993-03-23 Kawasaki Steel Corp 高靱性高温高強度フエライト系ステンレス鋼
JP2004218013A (ja) 2003-01-15 2004-08-05 Sumitomo Metal Ind Ltd 自動車排気系機器用フェライト系ステンレス鋼
JP2008240143A (ja) 2007-02-26 2008-10-09 Nippon Steel & Sumikin Stainless Steel Corp 耐熱性に優れたフェライト系ステンレス鋼板
JP2009174040A (ja) 2008-01-28 2009-08-06 Nisshin Steel Co Ltd Ｅｇｒクーラー用フェライト系ステンレス鋼およびｅｇｒクーラー
JP2013209726A (ja) * 2012-03-30 2013-10-10 Nippon Steel & Sumikin Stainless Steel Corp 加工性に優れた耐熱フェライト系ステンレス冷延鋼板、冷延素材用フェライト系ステンレス熱延鋼板及びそれらの製造方法
WO2013179616A1 (fr) * 2012-05-28 2013-12-05 Ｊｆｅスチール株式会社 Acier inoxydable ferritique
JP2015532681A (ja) * 2012-09-03 2015-11-12 アペラム・ステンレス・フランス フェライト系ステンレス鋼板、その製造方法、および特に排気管での使用
US20150345361A1 (en) * 2012-12-24 2015-12-03 Posco Ferritic Stainless Steel for Automotive Exhaust System, Which Have Excellent Corrosion Resistance Against Condensate, Moldability, and High-Temperature Oxidation Resistance, and Method for Manufacturing Same
JP2014145097A (ja) * 2013-01-28 2014-08-14 Nippon Steel & Sumikin Stainless Steel Corp 高温プレス成形に適する自動車排気系部材用のフェライト系ステンレス鋼板およびフェライト系ステンレス鋼成形部品の製造方法
JP2016204714A (ja) * 2015-04-24 2016-12-08 新日鐵住金ステンレス株式会社 自動車排気系部品締結部品用ステンレス鋼

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3517647A4

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MX2019007483A (es) 2019-08-29
JPWO2018116792A1 (ja) 2018-12-20
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KR20210062721A (ko) 2021-05-31
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EP3517647A4 (fr) 2019-12-04
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