EP2677056B1 - Acier inoxydable duplex - Google Patents

Acier inoxydable duplex Download PDF

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Publication number
EP2677056B1
EP2677056B1 EP12747362.7A EP12747362A EP2677056B1 EP 2677056 B1 EP2677056 B1 EP 2677056B1 EP 12747362 A EP12747362 A EP 12747362A EP 2677056 B1 EP2677056 B1 EP 2677056B1
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content
duplex stainless
stainless steel
steel
phase
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German (de)
English (en)
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EP2677056A1 (fr
EP2677056A4 (fr
Inventor
Kenta Yamada
Hiroyuki Nagayama
Masahiko Hamada
Daisuke MOTOYA
Hisashi Amaya
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Nippon Steel Corp
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Nippon Steel and Sumitomo Metal Corp
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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • C21D6/005—Heat treatment of ferrous alloys containing Mn
    • 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
    • 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
    • C22C38/02—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
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • 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
    • 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
    • C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
    • 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
    • C21D2211/001—Austenite
    • 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
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D7/00—Modifying the physical properties of iron or steel by deformation
    • C21D7/13—Modifying the physical properties of iron or steel by deformation by hot working

Definitions

  • the present invention relates to a line pipe made of a duplex stainless steel.
  • Petroleum oil and natural gas produced from oil fields and gas fields contain associated gas.
  • the associated gas contains corrosive gas such as carbon dioxide gas (CO 2 ) and hydrogen sulfide (H 2 S).
  • Line pipes transport the associated gas together with the petroleum oil and the natural gas.
  • the line pipes suffer from problems of stress corrosion cracking (SCC), sulfide stress corrosion cracking (sulfide stress cracking: SSC), and general corrosion cracking that causes a decrease in wall thickness.
  • SCC and SSC The propagation speeds of SCC and SSC are high. Hence, SCC and SSC penetrate through the line pipes in a short time from the occurrence thereof. Moreover, SCC and SSC locally occur.
  • steel materials for line pipes are required to have an excellent corrosion resistance (a SCC resistance, a SSC resistance, and a general corrosion resistance), and are required to have, particularly, a SCC resistance and a SSC resistance.
  • WO 96/18751 and JP 2003-171743A each propose a duplex stainless steel excellent in corrosion resistance.
  • the duplex stainless steel according to WO 96/18751 contains 1 to 3% of Cu.
  • WO 96/18751 describes that this increases the corrosion resistance of the duplex stainless steel under chloride and sulfide environments.
  • a method of producing the duplex stainless steel according to JP 2003-171743A involves properly adjusting the contents of Cr, Ni, Cu, Mo, N, and W and controlling the area fraction of a ferrite phase in the duplex stainless steel to 40 to 70%. JP 2003-171743A describes that this increases the strength, toughness, and seawater corrosion resistance of the duplex stainless steel.
  • JP H08-120413 discloses a casting member of two-phase stainless steel which has a composition which consists of, by weight ⁇ 0.08% C, ⁇ 0.9% Si, ⁇ 0.9% Mn, 5.0-8.0% NI, 24.0-30.0% Cr, 1.0-2.5% Mo, 2.6-3.5% Cu, 0.15-0.25% N, and the balance essential Fe or further contains ⁇ 0.005% B and in which the amount of Al contained as impurity is limited to ⁇ 0.05% and also has a structure composed of two-phase structure of austenite and ferrite.
  • JP H06-184698 discloses a stainless steel having a composition, which consists of ⁇ 0.08% C, 0.2-2% Si, 0.2-2% Mn, 3-6.0% Ni, 18-26% Cr, 1-4% Mo, 2-4% Cu, 0.5-3% W, 0.1-0.3% N, and the balance essential Fe and satisfies the relations in Cr+3.3Mo+16N ⁇ 30 (%), Cr+Mo+1.5Si ⁇ 27 (%), and Cu+W ⁇ 4 (%), and also having a structure which is composed essentially of austenite phase and ⁇ -ferrite phase and where the area ration of ⁇ -ferrite phase and austenite phase is regulated to 30/70 to 60/40 and 5-15% (by area) of martensite phase is mixed.
  • the corrosion resistance of a portion near a weld zone easily decreases, and the portion near the weld zone easily embrittles, at the time of high heat input welding.
  • the corrosion resistance of a portion near a weld zone easily decreases, and the portion near the weld zone easily embrittles, at the time of high heat input welding.
  • Such a decrease in the corrosion resistance of the portion near the weld zone and such an embrittlement thereof are caused by a sigma phase ( ⁇ phase) precipitating in the portion near the weld zone at the time of the high heat input welding.
  • the ⁇ phase is an intermetallic compound.
  • the SCC resistance is low under high-temperature chloride environments containing the associated gas and having a temperature range of 120 to 200°C.
  • steel materials for line pipes are required to have a high strength.
  • the steel materials are required to have a yield strength of 80 ksi (550 MPa or more).
  • The.present invention has an objective to provide a line pipe made of a duplex stainless steel that can suppress precipitation of a ⁇ phase at the time of high heat input welding, is excellent in SCC resistance under high-temperature chloride environments, and has a high strength.
  • a line pipe made of duplex stainless steel according to the present invention includes: a chemical composition consisting of, in mass percent, C: at most 0.020%, Si: 0.20 to 1.00%, Mn: 0.03 to 8.00%, P: at most 0.040%, S: at most 0.0100%, W: at most 0.1%, Cu: more than 2.00% and at most 4.00%, Ni: 4.00 to 8.00%, Cr: 20.0 to 28.0%, Mo: 0.50 to 2.00%, N: 0.100 to 0.350%, and sol.
  • the line pipe made of duplex stainless steel according to the present invention can suppress precipitation of a ⁇ phase at the time of high heat input welding and is excellent in SCC resistance under high-temperature chloride environments. Moreover, the line pipe made of duplex stainless steel according to the present invention has a high strength.
  • the inventors of the present invention carried out various experiments and detailed studies to obtain the following findings.
  • Figure 2 is a graph showing a relation between the ferrite rate (%) and the yield strength (MPa) of the duplex stainless steel within the range of the above-mentioned chemical composition according to the present invention.
  • the yield strength of the duplex stainless steel increases as the ferrite rate increases. Then, if the ferrite rate is equal to or more than 50%, the yield strength is equal to or more than 550 MPa.
  • "O" marks in Figure 2 fall within the range of the present invention, and " ⁇ " marks fall outside of the range of the present invention.
  • the duplex stainless steel according to the present invention has the following chemical composition.
  • Si Silicon (Si) suppresses a decrease in the flowability of molten metal at the time of welding, and suppresses the occurrence of a weld defect. Moreover, Si is a ferrite forming element. Meanwhile, if Si is excessively contained, an intermetallic compound typified by the ⁇ phase is more easily produced. Accordingly, the Si content is 0.20 to 1.00%. The upper limit of the Si content is preferably 0.80% and more preferably 0.65%. The lower limit of the Si content is preferably 0.30% and more preferably 0.35%.
  • Mn Manganese
  • N nitrogen
  • Mn is an austenite forming element. Meanwhile, if Mn is excessively contained, the corrosion resistance decreases. Accordingly, the Mn content is equal to or less than 8.00%.
  • the upper limit of the Mn content is preferably 7.50% and more preferably 5.00%.
  • the lower limit of the Mn content is 0.03% and preferably 0.05%.
  • Phosphorus (P) is an impurity. P decreases the corrosion resistance and toughness of the steel. Accordingly, it is preferable that the P content be low.
  • the P content is equal to or less than 0.040%.
  • the P content is preferably equal to or less than 0.030% and more preferably equal to or less than 0.020%.
  • S Sulfur
  • S is an impurity. S decreases the hot workability of the steel. Moreover, S forms sulfides. The sulfides become pitting occurrence origins, and thus decrease the pitting resistance of the steel. Accordingly, it is preferable that the S content be low.
  • the S content is equal to or less than 0.0100%.
  • the S content is preferably equal to or less than 0.0050% and more preferably equal to or less than 0.0010%.
  • Copper (Cu) strengthens a passivation film, and increases the corrosion resistance including the SCC resistance, under high-temperature chloride environments. Moreover, Cu extremely finely precipitates in the base material at the time of high heat input welding, and suppresses the precipitation of the ⁇ phase at the ferrite/austenite phase boundary. If the Cu content is more than 2.00%, an excellent corrosion resistance is obtained, and the precipitation of the ⁇ phase is suppressed. Meanwhile, if Cu is excessively contained, the hot workability of the steel decreases. Accordingly, the Cu content is more than 2.00% and equal to or less than 4.00%. The lower limit of the Cu content is preferably 2.20% and more preferably 2.40%.
  • the lower limit of the Ni content is preferably 4.20% and more preferably 4.50%.
  • the upper limit of the Ni content is preferably 7.00% and more preferably 6.00%.
  • Chromium (Cr) increases the corrosion resistance of the steel, and particularly increases the SCC resistance of the steel under high-temperature chloride environments. Moreover, Cr is a ferrite forming element. Meanwhile, if Cr is excessively contained, an intermetallic compound typified by the ⁇ phase is produced. Hence, the weldability of the steel decreases, and the hot workability thereof decreases. Accordingly, the Cr content is 20.0 to 28.0%.
  • the lower limit of the Cr content is preferably 22.0% and more preferably 24.0%.
  • the upper limit of the Cr content is preferably 27.5% and more preferably 27.0%.
  • Molybdenum (Mo) increases the SCC resistance of the steel. Moreover, Mo is a ferrite forming element. Meanwhile, if Mo is excessively contained, an intermetallic compound typified by the ⁇ phase is produced. Hence, the weldability of the steel decreases, and the hot workability thereof decreases. Accordingly, the Mo content is 0.50 to 2.00%. The lower limit of the Mo content is preferably 0.80% and more preferably 1.00%.
  • N Nitrogen
  • the duplex stainless steel according to the present invention contains Cr and Mo that are ferrite forming elements. If the balance of the amount of ferrite and the amount of austenite in the duplex stainless steel is taken into consideration, the N content is equal to or more than 0.100%. Meanwhile, if N is excessively contained, blow holes that are weld defects occur. If N is excessively contained, moreover, nitrides are more easily produced at the time of welding, and the toughness and corrosion resistance of the steel decrease. Accordingly, the N content is 0.100 to 0.350%. Moreover, the lower limit of the N content is preferably 0.120% and more preferably 0.150%. Moreover, the upper limit of the N content is preferably 0.330% and more preferably 0.300%.
  • Sol. Al 0.040% or less and 0.003% or more
  • Al deoxidizes the steel. Meanwhile, if Al is excessively contained, aluminum nitride (AlN) is formed, and the toughness and corrosion resistance of the steel decrease. Accordingly, the Al content is equal to or less than 0.040%.
  • the Al content herein means the content of acid-soluble Al (sol. Al).
  • the lower limit of the Al content is 0.003% and preferably 0.005%.
  • the upper limit of the Al content is preferably 0.035% and more preferably 0.030%.
  • the balance of the duplex stainless steel according to the present invention consists of Fe and impurities.
  • the impurities in this context mean elements mixed in for ores and scraps used as raw materials for the steel or various factors in a production process.
  • tungsten (W) is an impurity in the present invention. Specifically, the W content is equal to or less than 0.1%.
  • the chemical composition of the duplex stainless steel according to the present invention satisfies Expression (1) and Expression (2): 2.2 Cr + 7 Mo + 3 Cu > 66 Cr + 11 Mo + 10 Ni ⁇ 12 Cu + 30 N where the content (mass percent) of each element in the steel is substituted into the symbol of each element in Expression (1) and Expression (2).
  • the Cr content and the Mo content are restricted in order to suppress the precipitation of the ⁇ phase. Accordingly, it is preferable that a proper amount of Cu be contained, in order to strengthen a passivation film.
  • F1 2.2Cr + 7Mo + 3Cu.
  • F1 2.2Cr + 7Mo + 3Cu.
  • the chemical composition of the duplex stainless steel according to the present invention may contain, instead of Fe, one or more types of element selected from at least one group of the following first group to third group. That is, the elements in the first group to the third group are selective elements that can be contained as needed.
  • Vanadium (V) is a selective element. V increases the corrosion resistance of the duplex stainless steel, and particularly increases the corrosion resistance under acid environments. More specifically, if V is contained together with Mo and Cu, the crevice corrosion resistance of the steel increases. Meanwhile, if V is excessively contained, the amount of ferrite in the steel excessively increases, and the corrosion resistance of the steel decreases. Accordingly, the V content is equal to or less than 1.50%, and preferably less than 1.50%. If the V content is equal to or more than 0.05%, the above-mentioned effect can be remarkably obtained. However, even if the V content is less than 0.05%, the above-mentioned effect can be obtained to some extent.
  • the upper limit of the V content is preferably 0.50% and more preferably 0.10%.
  • Ca, Mg, and B immobilize S and O (oxygen) in the steel, and increase the hot workability of the steel.
  • the S content of the duplex stainless steel according to the present invention is low. Accordingly, even if Ca, Mg, and B are not contained, the hot workability of the steel is high. However, for example, in the case where a seamless steel pipe is produced according to a skew rolling method, a higher hot workability may be required. If one or more types selected from the group consisting of Ca, Mg, and B are contained, a higher hot workability can be obtained.
  • non-metallic inclusions such as oxides and sulfides of Ca, Mg, and B
  • the non-metallic inclusions become pitting origins, and thus decrease the corrosion resistance of the steel. Accordingly, the Ca content is equal to or less than 0.0200%, the Mg content is equal to or less than 0.020%, and the B content is equal to or less than 0.0200%.
  • the content of at least one type of Ca, Mg, and B or the total content of two or more types thereof be equal to or more than S (mass percent) + 1 / 2 ⁇ O (mass percent).
  • S mass percent
  • Mg, and B the total content of two or more types thereof
  • the total content of these elements is equal to or less than 0.04%. In the case where all of Ca, Mg, and B are contained, the total content of these elements is equal to or less than 0.06%.
  • Rare earth metal is a selective element. Similarly to Ca, Mg, and B, REM immobilizes S and O (oxygen) in the steel, and increases the hot workability of the steel. Meanwhile, if REM is excessively contained, non-metallic inclusions (such as oxides and sulfides of rare earth metal) increase, and the corrosion resistance of the steel decreases. Accordingly, the REM content is equal to or less than 0.2000%. In order to remarkably obtain the above-mentioned effect, it is preferable that the REM content be equal to or more than S (mass percent) + 1 / 2 ⁇ O (mass percent). However, if REM is contained even a little, the above-mentioned effect can be obtained to some extent.
  • REM is a collective term including 15 elements of lanthanoid, Y, and Sc. One or more types of these elements are contained. The REM content means the total content of one or more types of these elements.
  • the structure of the duplex stainless steel according to the present invention includes ferrite and austenite, and the balance thereof consists of precipitates and inclusions.
  • the ferrite rate is equal to or more than 50%.
  • the ferrite rate refers to the ferrite area fraction, and is measured according to the following method.
  • a sample is collected from a given portion of the duplex stainless steel.
  • the collected sample is mechanically polished, and then the polished sample is electrolytically etched in a 10% oxalic acid solution.
  • the electrolytically etched sample is further electrolytically etched in a 10% KOH solution.
  • An image of the electrolytically etched sample surface is analyzed using an optical microscope, and the ferrite rate is obtained.
  • the duplex stainless steel having the above-mentioned chemical composition is molten.
  • the duplex stainless steel may be molten using an electric furnace, and may be molten using an Ar-O 2 gaseous mixture bottom blowing decarburization furnace (AOD furnace).
  • AOD furnace Ar-O 2 gaseous mixture bottom blowing decarburization furnace
  • VOD furnace vacuum decarburization furnace
  • the molten duplex stainless steel may be formed into an ingot according to an ingot-making process, and may, be formed into a cast piece (a slab, a bloom, or a billet) according to a continuous casting process.
  • the duplex stainless steel material is produced using the produced ingot or cast piece.
  • Examples of the duplex stainless steel material include a duplex stainless steel plate and a duplex stainless steel pipe.
  • the duplex stainless steel plate is produced according to, for example, the following method. Hot working is performed on the produced ingot or slab, whereby the duplex stainless steel plate is produced. Examples of the hot working include hot forging and hot rolling.
  • the duplex stainless steel pipe is produced according to, for example, the following method. Hot working is performed on the produced ingot, slab, or bloom, whereby a billet is produced. Hot working is performed on the produced billet, whereby a duplex stainless steel pipe is produced. Examples of the hot working include piercing-rolling according to a Mannesmann process. Hot extrusion may be performed as the hot working, and hot forging may be performed thereas.
  • the produced duplex stainless steel pipe may be a seamless pipe, and may be a welded steel pipe.
  • duplex stainless steel pipe is a welded steel pipe
  • bending work is performed on the above-mentioned duplex stainless steel pipe, to be thereby formed into an open pipe.
  • Both the end faces in the longitudinal direction of the open pipe are welded according to a well-known welding method such as submerged arc welding, whereby the welded steel pipe is produced.
  • Solution treatment is performed on the produced duplex stainless steel material.
  • the duplex stainless steel material is housed in a heat treatment furnace, and is soaked at a solution treatment temperature (°C). After the soaking, the duplex stainless steel is rapidly cooled by water-cooling or the like.
  • the soaking time in the solution treatment is preferably 2 to 60 minutes.
  • the duplex stainless steel material according to the present invention remains in a solution state (so-called as-solution-treated material). That is, after the solution treatment, the duplex stainless steel material is used as a product without performing thereon other heat treatment and other cold working (cold drawing and Pilger rolling) than cold straightening.
  • Duplex stainless steels having various chemical compositions were molten using a vacuum furnace having a capacity of 150 kg.
  • a plurality of duplex stainless steel plates were produced using the molten duplex stainless steels according to various production conditions.
  • the ferrite rate, the yield strength, the SCC resistance, and whether or not the ⁇ phase precipitated at the time of high heat input welding were examined using the produced steel plates.
  • Duplex stainless steels having chemical compositions of the steel A to the steel Z shown in Table 1 were molten.
  • the contents (mass percents) of the corresponding elements in the steel with each steel symbol are shown in the chemical composition section in Table 1.
  • the balance (components other than the elements shown in Table 1) in the chemical composition of each steel symbol consists of Fe and impurities.
  • "-" in Table 1 represents that the content of the corresponding element is in an impurity level.
  • Selective elements other than W contained in the corresponding steel are shown in the "Others” section in Table 1. For example, ".023B-.0026Ca" represents that the B content is 0.023% and that the Ca content is 0.0026%.
  • the molten duplex stainless steels were cast, whereby ingots were produced.
  • the produced ingots were each heated to 1,250°C.
  • Hot forging was performed on the heated ingots, whereby plate materials were produced.
  • the produced plate materials were heated again to 1,250°C.
  • Hot rolling was performed on the heated plate materials, whereby steel plates each having a thickness of 15 mm were produced.
  • the surface temperature of each steel material at the time of the rolling was 1,050°C.
  • Solution treatment was performed on the produced steel plates.
  • the solution treatment temperature was 1,070°C to 1,200°C, and the soaking time was 30 minutes. After the soaking, the steel plates were water-cooled to reach a normal temperature (25°C), whereby materials under test with the test numbers 1 to 32 were produced.
  • Figure 3A is a plan view of the plate material 10
  • Figure 3B is a front view thereof.
  • numerical values with "mm" represent dimensions (the unit is millimeter).
  • the plate material 10 had a thickness of 12 mm, a width of 100 mm, and a length of 200 mm. Moreover, the plate material had a V-type groove surface 11 on its longer side, and the V-type groove surface 11 had a groove angle of 30°. The plate material 10 was made by machine processing.
  • the V-type groove surfaces 11 of the two made plate materials 10 were placed so as to be opposed to each other.
  • the two plate materials 10 were welded according to tungsten inert gas welding, whereby a welded joint 20 illustrated in Figure 4A and Figure 4B was made.
  • Figure 4A is a plan view of the welded joint 20, and
  • Figure 4B is a front view thereof.
  • the welded joint 20 had a front surface 21 and a back surface 22, and included a weld zone 30 in its center.
  • the weld zone 30 was formed from the front surface 21 side according to multi-layer welding, and extended in the longer-side direction of the plate materials 10.
  • All the weld zones 30 with their respective test numbers were formed using a weld material having the same chemical composition as that of the steel A and having an outer diameter of 2 mm.
  • the heat input in the tungsten inert gas welding was 30 kJ/cm.
  • a plate-shaped specimen 40 including the weld zone 30 was collected from the back surface 22 side of the welded joint 20.
  • a broken line portion of the welded joint 20 in Figure 5B shows a portion from which the specimen 40 was collected.
  • Figure 5 is a perspective view of the collected specimen.
  • numerical values with "mm" represent dimensions (the unit is millimeter).
  • the specimen 40 had a plate-like shape.
  • An upper surface 41 of the specimen 40 corresponded to the back surface 22 of the welded joint (see Figure 4 ).
  • the longitudinal direction of the specimen 40 was orthogonal to the longitudinal direction of the weld zone 30. As illustrated in Figure 5 , one of two boundary lines 30B between the weld zone 30 and the plate materials 10 was placed in the center of the specimen 40.
  • a four-point bending test was performed using the specimen 40, and the SCC resistance of each material under test was evaluated.
  • An actual yield stress (the yield stress of each material under test) in conformity to ASTM G39 was applied to the specimen 40 using a four-point bending jig.
  • the specimen 40 to which the stress was applied was immersed in a 25%-NaCl aqueous solution (150°C) into which CO 2 was injected at 3 MPa, and the immersed specimen 40 was held for 720 hours without any change. After the elapse of 720 hours, whether or not SCC occurred on a surface of the specimen 40 was visually observed. Moreover, the specimen 40 was cut in a direction perpendicular to the upper surface 41. The cross-section of the specimen 40 was observed using a 500x optical microscope, and whether or not SCC occurred was determined.
  • the welded joint 20 with each test number was cut in a direction perpendicular to the weld line and the front surface 21 thereof. After the cutting, the cross-section of the welded joint 20 was mirror-polished and etched. After the etching, a welding heat affected zone (HAZ; a portion near the weld zone) of the etched cross-section was selected for four visual fields, and an image in each visual field was analyzed, using an optical microscope with ⁇ 500 field. The area of each visual field used for the image analysis was about 40,000 ⁇ m 2 . The area fraction (%) of the ⁇ phase for each visual field (HAZ) was obtained through the image analysis.
  • HZ welding heat affected zone
  • the average of the area fractions (%) obtained for the four visual fields was defined as the area fraction (%) of the ⁇ phase in the HAZ for each test number. In the case where the area fraction of the ⁇ phase was equal to or more than 0.5%, it was determined that the ⁇ phase precipitated. In the case where the area fraction of the ⁇ phase was less than 0.5%, it was determined that the ⁇ phase did not precipitate.
  • a round bar tensile specimen was collected from each material under test.
  • the round bar tensile specimen had an outer diameter of 6.35 mm and a parallel part length of 25.4 mm. The parallel part thereof extended in the rolling direction of the material under test.
  • a tensile test was performed on the collected round bar specimen at a normal temperature.
  • An offset yield stress of 0.2% based on ASTM A370 was defined as the yield strength (YS).
  • the ferrite rate of each material under test was obtained according to the following method.
  • a specimen for structure observation was collected from each material under test.
  • the collected specimen was mechanically polished.
  • the polished specimen was electrolytically etched in a 10% oxalic acid solution.
  • the electrolytically etched specimen was further electrolytically etched in a 10% KOH solution.
  • the etched sample surface was selected for four visual fields, and an image in each visual field was analyzed, using an optical microscope (500 ⁇ ). At this time, the area of the observed region was about 40,000 ⁇ m 2 .
  • the ferrite rate (%) in the observed region was obtained.
  • the test results are shown in Table 1.
  • a solution treatment temperature (°C) is inputted to the "Solution Treatment Temperature” section.
  • a ferrite rate (%) is inputted to the “Ferrite Rate” section.
  • a yield strength (MPa) is inputted to the "YS (MPa)” section.
  • a yield strength (ksi) is inputted to the "YS (ksi)” section.
  • the chemical compositions of materials under test with test numbers 1 to 4, 6 to 8 fell within the range of the present invention. Moreover, the materials under test with the test numbers 1 to 4, 6 to 8 satisfied Expression (1) and Expression (2). Hence, SCC was not observed in the materials under test with the test numbers 1 to 4, 6 to 8, and the ⁇ phase did not occur therein. Moreover, the ferrite rates of the materials under test with the test numbers 1 to 4, 6 to 8 were equal to or more than 50%, and the yield strengths thereof were equal to or more than 550 MPa.
  • the chemical compositions of materials under test with test numbers 9 to 14, 16 to 18 fell within the range of the present invention. Moreover, the materials under test with the test numbers 9 to 14, 16 to 18 satisfied Expression (1) and Expression (2). However, the ferrite rates of the materials under test with the test numbers 9 to 14, 16 to 18 were less than 50%, and the yield strengths thereof were less than 550 MPa.
  • the Cr content of a material under test with a test number 19 was less than the lower limit of the Cr content according to the present invention.
  • SCC occurred in the material under test with the test number 19.
  • the N content of a material under test with a test number 20 was less than the lower limit of the N content according to the present invention.
  • the material under test with the test number 20 did not satisfy Expression (1) and Expression (2).
  • the ⁇ phase occurred in a HAZ of the material under test with the test number 20, and SCC occurred in the material under test with the test number 20.
  • the Ni content of a material under test with a test number 22 was less than the lower limit of the Ni content according to the present invention. Moreover, the test number 22 did not satisfy Expression (1). Hence, SCC occurred in the material under test with the test number 22.
  • the C content of a material under test with a test number 23 was more than the upper limit of the C content according to the present invention, and the Ni content thereof was less than the lower limit of the Ni content according to the present invention. Moreover, the material under test with the test number 23 did not satisfy Expression (1). Hence, SCC occurred in the material under test with the test number 23.
  • the Cu content of a material under test with a test number 27 was less than the lower limit of the Cu content according to the present invention, and the Mo content thereof was more than the upper limit of the Mo content according to the present invention. Hence, SCC occurred in the material under test with the test number 27, and the ⁇ phase occurred therein.
  • the Cu content of a material under test with a test number 30 was less than the lower limit of the Cu content according to the present invention. Hence, SCC occurred in the material under test with the test number 30, and the ⁇ phase occurred therein.
  • the present invention has been described, and the above-mentioned embodiment is given as a mere example for carrying out the present invention. Accordingly, the present invention is not limited to the above-mentioned embodiment, and can be carried out by appropriately modifying the above-mentioned embodiment within a range not departing from the gist thereof.
  • a line pipe made of duplex stainless steel according to the present invention can be widely applied to environments that are required to have a SCC resistance.
  • a line pipe made of duplex stainless steel according to the present invention is applicable as a steel material for a line pipe provided under chloride environments.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Steel (AREA)
  • Heat Treatment Of Sheet Steel (AREA)

Claims (2)

  1. Tuyau de conduite en acier inoxydable duplex comprenant :
    une composition chimique constituée par, en pourcentage en masse, C : au maximum 0,020 %, Si : 0,20 à 1,00 %, Mn : 0,03 à 8,00 %, P : au maximum 0,040 %, S : au maximum 0,0100 %, W : au maximum 0,1 %, Cu : plus de 2,00 % et au maximum 4,00 %, Ni : 4,00 à 8,00 %, Cr : 20,0 à 28,0 %, Mo : 0,50 à 2,00 %, N : 0,100 à 0,350 %, et Al sol. : 0,003 à 0,040 %, et éventuellement V : au maximum 1,50 %, Ca : au maximum 0,0200 %, Mg au maximum 0,020 %, B : au maximum 0,0200 %, métal de terres rares : au maximum 0,2000 %, le reste étant Fe et des impuretés, et satisfaisant à l'Expression (1) et l'Expression (2) ;
    une structure présentant un taux de ferrite d'au moins 50 % ; et
    une limite d'élasticité d'au moins 550 MPa : 2 , 2 Cr + 7 Mo + 3 Cu > 66
    Figure imgb0012
     Cr + 11 Mo + 10 Ni < 12 Cu + 30 N
    Figure imgb0013
     où la teneur (en pourcentage en masse) de chaque élément dans l'acier est substituée par le symbole de chaque élément dans l'Expression (1) et l'Expression (2).
  2. Tuyau de conduite en acier inoxydable duplex selon la revendication 1, dans lequel la composition chimique comprend V : 0,05 à 1,50 %.
EP12747362.7A 2011-02-14 2012-02-10 Acier inoxydable duplex Active EP2677056B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2011028334 2011-02-14
PCT/JP2012/053037 WO2012111537A1 (fr) 2011-02-14 2012-02-10 Acier inoxydable duplex

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Families Citing this family (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2476771B1 (fr) * 2009-09-10 2015-03-04 Nippon Steel & Sumitomo Metal Corporation Acier inoxydable à deux phases
CA2826880C (fr) * 2011-02-14 2017-07-25 Nippon Steel & Sumitomo Metal Corporation Acier inoxydable duplex et procede pour la production de celui-ci
EP2754726B1 (fr) * 2011-09-06 2019-02-27 Nippon Steel & Sumitomo Metal Corporation Acier inoxydable à deux phases
CN103938115A (zh) * 2014-03-03 2014-07-23 黄忠波 一种双相不锈钢合金材料
CN105986196A (zh) * 2015-03-05 2016-10-05 中国科学院金属研究所 一种耐微生物腐蚀的双相不锈钢
US10793930B2 (en) 2016-02-17 2020-10-06 Nippon Steel & Sumikin Stainless Steel Corporation Ferritic-austenitic two-phase stainless steel material and method for manufacturing same
AU2017274993B2 (en) * 2016-06-01 2019-09-12 Nippon Steel Corporation Duplex stainless steel and duplex stainless steel manufacturing method
WO2018043214A1 (fr) * 2016-09-02 2018-03-08 Ｊｆｅスチール株式会社 Acier inoxydable duplex et procédé pour sa fabrication
JP6780426B2 (ja) * 2016-10-06 2020-11-04 日本製鉄株式会社 二相ステンレス鋼
JP6946737B2 (ja) * 2017-05-18 2021-10-06 日本製鉄株式会社 二相ステンレス鋼材及びその製造方法
CN109648064B (zh) * 2019-01-25 2021-04-20 北京科技大学 一种超级奥氏体不锈钢凝固组织σ相变性的方法
BR112021012900B1 (pt) * 2019-01-30 2024-01-23 Jfe Steel Corporation Aço inoxidável duplex, cano ou tubo de aço sem costura e um método de fabricação do aço inoxidável duplex
EP3960885B1 (fr) * 2019-04-24 2024-04-10 Nippon Steel Corporation Tuyau en acier sans soudure en acier inoxydable duplex et procédé pour produire un tuyau en acier sans soudure en acier inoxydable duplex
BR112021022956A2 (pt) * 2019-05-29 2022-01-18 Jfe Steel Corp Aço inoxidável duplex e método para fabricar o mesmo, e tubo de aço inoxidável duplex
US20220145438A1 (en) * 2019-08-19 2022-05-12 Nippon Steel Corporation Duplex stainless steel material
WO2022004526A1 (fr) * 2020-06-30 2022-01-06 日本製鉄株式会社 Tuyau en acier inoxydable à deux phases et raccord soudé
CN113210420B (zh) * 2021-04-21 2022-12-06 鞍钢联众(广州)不锈钢有限公司 一种双相不锈钢钢卷及其制造方法

Family Cites Families (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS505972B1 (fr) * 1970-05-11 1975-03-10
JPS5340656A (en) * 1973-02-07 1978-04-13 Nippon Yakin Kogyo Co Ltd Electrode core wire provided for stainless steel welding
JPS5424364B2 (fr) * 1973-05-04 1979-08-21
JPS51117916A (en) * 1975-04-10 1976-10-16 Daido Steel Co Ltd Ferrite-austenite type two phase stainless steel
JPS55158256A (en) * 1979-05-29 1980-12-09 Daido Steel Co Ltd Ferritic-austenitic two-phase stainless steel
JP2790749B2 (ja) * 1992-03-27 1998-08-27 株式会社クボタ ドリル及びバイト加工性にすぐれる二相ステンレス鋼
JP2881361B2 (ja) * 1992-12-17 1999-04-12 株式会社クボタ 高腐食疲労強度ステンレス鋼
JPH06184699A (ja) * 1992-12-17 1994-07-05 Kubota Corp 高腐食疲労強度ステンレス鋼
JP3155431B2 (ja) * 1994-10-26 2001-04-09 株式会社安来製作所 ２相ステンレス鋳造部材およびその製造方法
JP3271262B2 (ja) 1994-12-16 2002-04-02 住友金属工業株式会社 耐食性にすぐれた二相ステンレス鋼
JPH1060526A (ja) * 1996-08-19 1998-03-03 Nkk Corp 耐海水性用析出強化型二相ステンレス鋼の製造方法
JP2000313940A (ja) * 1999-04-27 2000-11-14 Sumitomo Metal Ind Ltd 二相ステンレス鋼材およびその製造方法
JP3534032B2 (ja) * 2000-02-03 2004-06-07 住友金属工業株式会社 ２相ステンレス鋼製鋼管の製造方法
JP2003171743A (ja) 2001-12-06 2003-06-20 Aichi Steel Works Ltd 強度、靭性、耐海水性の優れた二相ステンレス鋼及びその製造方法
JP4502131B2 (ja) * 2005-09-20 2010-07-14 住友金属工業株式会社 熱間加工性に優れた二相ステンレス鋼
PL2229463T3 (pl) * 2007-12-20 2018-01-31 Ati Properties Llc Odporna na korozję zubożona austenityczna stal nierdzewna
EP2476771B1 (fr) * 2009-09-10 2015-03-04 Nippon Steel & Sumitomo Metal Corporation Acier inoxydable à deux phases

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None *

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MX2013008518A (es) 2013-08-12
WO2012111537A1 (fr) 2012-08-23
CN103370435B (zh) 2016-04-20
BR112013017647A2 (pt) 2016-12-20
EP2677056A1 (fr) 2013-12-25
EP2677056A4 (fr) 2015-03-25
BR112013017647B1 (pt) 2019-03-26
US20130315776A1 (en) 2013-11-28
AU2012218661B2 (en) 2015-04-30
CA2826893A1 (fr) 2012-08-23
JPWO2012111537A1 (ja) 2014-07-07
CN103370435A (zh) 2013-10-23
MX351782B (es) 2017-10-30
JP5206904B2 (ja) 2013-06-12
CA2826893C (fr) 2016-06-07
AU2012218661A1 (en) 2013-09-05

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