WO2021161366A1 - Tube en acier soudé par résistance électrique à usage de tube de canalisation - Google Patents

Tube en acier soudé par résistance électrique à usage de tube de canalisation Download PDF

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Publication number
WO2021161366A1
WO2021161366A1 PCT/JP2020/005072 JP2020005072W WO2021161366A1 WO 2021161366 A1 WO2021161366 A1 WO 2021161366A1 JP 2020005072 W JP2020005072 W JP 2020005072W WO 2021161366 A1 WO2021161366 A1 WO 2021161366A1
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Prior art keywords
resistance
electric
less
content
pipe
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PCT/JP2020/005072
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English (en)
Japanese (ja)
Inventor
原　卓也
坂本　真也
修治 岩本
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日本製鉄株式会社
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Priority to EP20919182.4A priority Critical patent/EP4066954A4/fr
Priority to KR1020227021826A priority patent/KR20220105166A/ko
Priority to JP2021577721A priority patent/JP7226595B2/ja
Priority to PCT/JP2020/005072 priority patent/WO2021161366A1/fr
Publication of WO2021161366A1 publication Critical patent/WO2021161366A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • 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
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
    • B21C37/06—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of tubes or metal hoses; Combined procedures for making tubes, e.g. for making multi-wall tubes
    • B21C37/08—Making tubes with welded or soldered seams
    • 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
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/56—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering characterised by the quenching agents
    • C21D1/60—Aqueous agents
    • 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
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C21D8/105—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C21D9/085—Cooling or quenching
    • 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
    • C21D9/50—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for welded joints
    • C21D9/505—Cooling thereof
    • 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
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • 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
    • C22C38/08—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
    • 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
    • C22C38/14—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing 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
    • C22C38/26—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
    • C22C38/40—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
    • C22C38/54—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
    • C21D2211/003—Cementite
    • 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
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/009—Pearlite

Definitions

  • This disclosure relates to electric resistance sewn steel pipes for line pipes.
  • a pipeline is a system constructed on the ground or the seabed, and is a system for transferring oil and gas.
  • a pipeline is formed by connecting a plurality of line pipes.
  • As the steel pipe for such a line pipe an electrosewn steel pipe may be used.
  • the area where pipelines are constructed has expanded to areas with harsh environments such as the sour environment.
  • the sour environment including H 2 S is a corrosive gas, means acidified environment.
  • the pipeline constructed in the sour environment, the line pipe for forming the pipeline, and the steel pipe for the line pipe have sulfide stress cracking resistance (Sulfide Stress Cracking resistance: hereinafter referred to as SSC resistance). ) Is required.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 6-41684 (Patent Document 1) and Japanese Patent Application Laid-Open No. 6-235405 (Patent Document 2) disclose techniques for improving the SCC resistance of electric resistance welded steel pipes for line pipes. There is.
  • the electrosewn steel pipe disclosed in Patent Document 1 has C: 0.05 to 0.35%, Si: 0.02 to 0.50%, Mn: 0.30 to 2.00%, Ca: 0.0005. It is made of steel containing ⁇ 0.0080%, Al: 0.005 to 0.100%, and the balance is Fe.
  • This electrosewn steel pipe has S, O, and Ca contents satisfying the formula (1.0 ⁇ (% Ca) ⁇ 1-72 (% O) ⁇ / 1.25 (% S) ⁇ 2.5).
  • the deoxidized product is a composite inclusion of (CaO) m (Al 2 O 3 ) n , and the hardness is measured within 30 mm on both sides with m / n ⁇ 1 and the electro-sewing abutment surface as the center.
  • the maximum value is 250 or less in Vickers hardness, and the difference between the maximum value and the minimum value is 30 or less in Vickers hardness.
  • Paragraph 0063 of Patent Document 1 describes that the electric resistance welded steel pipe has high strength and excellent sulfide stress corrosion cracking resistance even in a harsh environment with a low pH.
  • the electrosewn steel pipe disclosed in Patent Document 2 has a weight% of C: 0.05 to 0.35%, Si: 0.02 to 0.50%, Mn: 0.30 to 2.00%, P. : 0.030% or less, S: 0.005% or less, Ca: 0.0005 to 0.0080%, Al: 0.005 to 0.100%, and the content of S, O, Ca is the formula. (1.0 ⁇ (% Ca) ⁇ 1-72 (% O) ⁇ / 1.25 (% S) ⁇ 2.5) is satisfied, and the relationship between the amount of O and the amount of Ca is (% Ca) / (%). O) Satisfies ⁇ 0.55 and is made of steel consisting of the balance Fe and unavoidable impurities.
  • the maximum value of the measured hardness within 30 mm on both sides of the electric resistance joint surface is 250 or less in Vickers hardness, and the difference between the maximum value and the minimum value is 30 in Vickers hardness.
  • Paragraph 0059 of Patent Document 2 describes that the electric resistance welded steel pipe does not deteriorate the SSC characteristics even in a harsh environment with a low pH.
  • Patent Document 1 Japanese Patent Application Laid-Open No. 6-41684
  • Patent Document 2 Japanese Patent Application Laid-Open No. 6-235405
  • SSC sulfide stress cracking
  • SSC stress-dominated hydrogen-induced cracking
  • SOHIC -Oriented Hydrogen Induced Cracking
  • Patent Documents 1 and 2 do not describe SOHIC resistance. Therefore, even if the techniques disclosed in Patent Documents 1 and 2 are applied to the electrosewn steel pipe for line pipes used in a sour environment, excellent SOHIC resistance may not be obtained.
  • An object of the present disclosure is to provide an electrosewn steel pipe for a line pipe having excellent SSC resistance and SOHIC resistance.
  • Means for solving the above problems include the following aspects. ⁇ 1> Including the base metal part and the electric sewing welded part
  • the chemical composition of the base material is mass%. C: 0.030-0.090%, Si: 0.01-0.50%, Mn: 0.50 to 1.50%, P: 0 to 0.020%, S: 0 to 0.0020%, Nb: 0.005 to 0.060%, Ti: 0.005 to 0.030%, Ca: 0.0001 to 0.0040%, Al: 0 to 0.050%, N: 0.0010 to 0.0080%, O: 0 to 0.0030%, Cu: 0 to 0.500%, Ni: 0 to 0.500%, B: 0 to 0.0020%, V: 0 to 0.100%, Cr: 0 to 0.500%, Mo: 0 to 0.500%, W: 0 to 0.500%, Zr: 0-0.0500%, Ta: 0-0.0500%, Mg: 0 to 0.0050%, REM: 0-0.0050%, Hf:
  • the yield strength of the base material portion is 410 MPa or more, and the tensile strength of the base material portion is 515 to 650 MPa.
  • ⁇ YS which is a value obtained by subtracting the yield strength of the electric sewing welded portion from the yield strength of the base metal portion, is 0 to 80 MPa.
  • ⁇ Hv which is a value obtained by subtracting the Vickers hardness of the inner surface layer of the electric sewing welded portion from the Vickers hardness of the outer surface layer of the electric sewing welded portion, is 0 to 25 Hv.
  • the chemical composition of the base material is mass%.
  • Cu More than 0% and less than 0.500%
  • Ni More than 0% and less than 0.500%
  • B More than 0% and less than 0.0020%
  • V More than 0% and less than 0.100%
  • Cr More than 0% and less than 0.500%
  • Mo More than 0% and less than 0.500%
  • W More than 0% and less than 0.500%
  • Zr More than 0% and less than 0.0500%
  • Ta More than 0% and less than 0.0500%
  • Mg More than 0% and less than 0.0050%
  • REM More than 0% and less than 0.0050%
  • Hf More than 0% and less than 0.0050%
  • Re Contains one or more selected from the group consisting of more than 0% and 0.0050% or less.
  • ⁇ 3> The electrosewn steel pipe for a line pipe according to ⁇ 1> or ⁇ 2>, which has a wall thickness of 13 mm or more.
  • ⁇ 4> The electric resistance welded steel pipe for a line pipe according to any one of ⁇ 1> to ⁇ 3>, which has an outer diameter of 300 mm to 650 mm.
  • an electrosewn steel pipe for a line pipe having excellent SSC resistance and SOHIC resistance is provided.
  • the numerical range represented by using “-” means a range including the numerical values before and after “-” as the lower limit value and the upper limit value.
  • “%” indicating the content of a component (element) means “mass%”.
  • the content of C (carbon) may be referred to as “C content”.
  • the content of other elements may be described in the same manner.
  • the term “process” is included in this term not only as an independent process but also as long as the intended purpose of the process is achieved even if it cannot be clearly distinguished from other processes. Is done.
  • the electrosewn steel pipe for line pipes of the present disclosure (hereinafter, also simply referred to as “the electrosewn steel pipe of the present disclosure”) includes a base material portion and an electrosewn welded portion, and the chemical composition of the base metal portion is C by mass%. : 0.030 to 0.090%, Si: 0.01 to 0.50%, Mn: 0.50 to 1.50%, P: 0 to 0.020%, S: 0 to 0.0020%, Nb: 0.005 to 0.060%, Ti: 0.005 to 0.030%, Ca: 0.0001 to 0.0040%, Al: 0 to 0.050%, N: 0.0010 to 0.
  • the polygonal ferrite content is 80% or more and less than 100%, the balance contains pseudo-pearlite and cementite, and the yield strength of the base material is 410 MPa or more.
  • the tensile strength of the base metal portion is 515 to 650 MPa, and ⁇ YS, which is the value obtained by subtracting the yield strength of the electrosewn welded portion from the yield strength of the base metal portion, is 0 to 80 MPa, and the outer surface layer of the electrosewn welded portion.
  • ⁇ Hv which is the value obtained by subtracting the Vickers hardness of the inner surface layer of the electric sewing welded portion from the Vickers hardness of the above, is 0 to 25 Hv.
  • the base metal portion refers to a portion of the electric resistance steel pipe other than the electric resistance welded portion and the heat-affected zone.
  • the heat-affected zone (sometimes referred to as "HAZ") refers to a portion in the vicinity of the electric sewing welded zone, which is affected by heat due to electric sewing welding and seam heat treatment. Point.
  • the electrosewn steel pipe of the present disclosure has excellent SSC resistance and SOHIC resistance. Hereinafter, this effect will be described in detail.
  • the present inventors satisfy all the requirements other than the requirements of ⁇ YS and ⁇ Hv (that is, the requirement that ⁇ YS is 0 to 80 MPa and ⁇ Hv is 0 to 25 Hv) in the electric resistance welded steel pipe of the present disclosure (that is, the electric resistance welded steel pipe that satisfies all the requirements.
  • the SSC resistance and SOHIC resistance of (hereinafter referred to as "electric pipe X") were investigated. As a result, it was found that the SSC resistance and / or the SOHIC resistance of the electric resistance welded portion of the electric resistance steel pipe X may be lowered. Therefore, the present inventors first considered the reason why the SSC resistance is lowered as follows.
  • the strength of the electric sewn welded part of the electric sewn steel pipe is generally higher than the strength of the base metal part (that is,). , ⁇ YS is a negative value). If the strength of the electric-sewn welded portion of the electric-sewn steel pipe is too high, SSC is likely to occur in the electric-sewn welded portion of the electric-sewn steel pipe. As a method of suppressing the generation of SSC, it is conceivable to apply a heat treatment (hereinafter, also referred to as "seam heat treatment”) to the electric stitch welded portion to reduce the strength of the electric stitch welded portion.
  • a heat treatment hereinafter, also referred to as "seam heat treatment
  • the electric resistance pipe X that is, the electric resistance pipe satisfying the requirements other than the requirements of ⁇ YS and ⁇ Hv in the present disclosure
  • the electric resistance welded portion It was found that SSC may occur in.
  • the yield strength of the electric resistance welded portion which is considered to be higher than the yield strength of the base metal portion, tends to be lower than the yield strength of the base metal portion (that is, ⁇ YS is high). It also tends to be a positive value). Therefore, the present inventors have examined in more detail the relationship between the SSC in the electric resistance welded portion of the electric resistance pipe X and the ⁇ YS in the electric resistance pipe X.
  • SSC Sulfide Stress Cracking
  • the internal pressure of the electric resistance welded steel pipe increased during use causes plastic strain (that is, strain in the plastic region) to be applied to the electric resistance welded portion.
  • plastic strain that is, strain in the plastic region
  • the plastic strain applied to is increased. As a result, hydrogen is occluded in the plastic strain of the electric stitch welded portion, and SSC is likely to be generated in the electric stitch welded portion. It is considered that SSC having the above mechanism is likely to occur in the electric resistance welded steel pipe X in which ⁇ YS tends to be a positive value.
  • the present inventors do not reduce the yield strength of the electric stitch welded portion too much, and bring the yield strength of the electric stitch welded portion close to the yield strength of the base metal portion, specifically, ⁇ YS is 0. It has been found that the SSC in the electric sewing welded portion can be suppressed (that is, the SSC resistance in the electric sewing welded portion can be improved) by adjusting the value to about 80 MPa.
  • the present inventors investigated the Vickers hardness of the electric resistance welded portion of the electric resistance steel pipe X in which ⁇ YS was 0 to 80 MPa. As a result, when ⁇ Hv, which is the value obtained by subtracting the Vickers hardness of the inner surface layer of the electric stitch welded portion from the Vickers hardness of the outer surface layer of the electric stitch welded portion, exceeds 25 Hv, SOHIC is generated in the electric stitch welded portion. It was found that
  • the present inventors in the case where ⁇ YS is 0 to 80 MPa and ⁇ Hv is 0 to 25 Hv in the welded steel pipe X (that is, when it corresponds to the welded steel pipe of the present disclosure), the electric pipe is electric. It has been found that the SSC resistance and the SOHIC resistance of the sewn welded portion can be improved. That is, the present inventors have found that the above-described electrosewn steel pipe of the present disclosure has excellent SSC resistance and SOHIC resistance.
  • C 0.030-0.090%
  • C (carbon) is an element that enhances the strength of steel materials. If the C content is too low, the above effect may not be obtained. On the other hand, if the C content is too high, C may form carbides with alloying elements in the steel material, which may reduce the SSC resistance and SOHIC resistance of the steel material. Further, if the C content is too high, the strength of the steel material becomes too high, and ⁇ YS and ⁇ Hv become too large, and as a result, the SSC resistance and the SOHIC resistance of the steel material may decrease. Therefore, the C content is 0.030 to 0.090%.
  • the lower limit of the C content is preferably 0.035%, more preferably 0.040%.
  • the upper limit of the C content is preferably 0.080%, more preferably 0.070%.
  • Si 0.01-0.50% Si is an element that deoxidizes steel. If the Si content is too low, the above effect may not be obtained. On the other hand, if the Si content is too high, the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Si content is 0.01 to 0.50%.
  • the lower limit of the Si content is preferably 0.02%, more preferably 0.05%.
  • the upper limit of the Si content is preferably 0.40%, more preferably 0.35%.
  • Mn 0.50 to 1.50%
  • Mn is an element that deoxidizes steel. Mn is also an element that enhances the strength of steel materials. If the Mn content is too low, the above effect may not be obtained. On the other hand, if the Mn content is too high, the strength of the steel material may become too high. In this case, ⁇ YS may be further increased, and ⁇ Hv may be further increased. In these cases, the SSC resistance and SOHIC resistance of the steel material are lowered. Therefore, the Mn content is 0.50 to 1.50%.
  • the lower limit of the Mn content is preferably 0.60%, more preferably 0.80%, and even more preferably 1.00%.
  • the upper limit of the Mn content is preferably 1.40%, more preferably 1.35%.
  • P 0 to 0.020%
  • P (phosphorus) is an impurity.
  • the P content may be 0% or more than 0%.
  • P may segregate at the grain boundaries and reduce the SSC resistance and / or the SOHIC resistance of the steel material. Therefore, the P content is 0 to 0.020%.
  • the upper limit of the P content is preferably 0.015%, more preferably 0.013%.
  • the P content is preferably as low as possible. However, an extreme reduction in P content may significantly increase the manufacturing cost of steel materials. Therefore, when considering industrial production, the lower limit of the P content is preferably 0.001%, more preferably 0.005%.
  • S is an impurity.
  • the S content may be 0% or more than 0%.
  • S may segregate at the grain boundaries and reduce the SSC resistance and / or the SOHIC resistance of the steel material. Therefore, the S content is 0 to 0.0020%.
  • the upper limit of the S content is preferably 0.0015%, more preferably 0.0010%, and even more preferably 0.0008%.
  • the S content is preferably as low as possible. However, an extreme reduction in the S content may significantly increase the manufacturing cost of the steel material. Therefore, when considering industrial production, the lower limit of the S content is preferably 0.0001%, more preferably 0.0002%.
  • Nb 0.005 to 0.060%
  • Nb is an element that combines with C (carbon) and / or N (nitrogen) to form carbides, nitrides or carbonitrides (hereinafter referred to as "carbonitrides and the like").
  • the carbonitride and the like refine the substructure of the steel material by the pinning effect, and enhance the SSC resistance and / or the SOHIC resistance of the steel material. If the Nb content is too low, the above effect may not be obtained. On the other hand, if the Nb content is too high, the carbonitride and the like may become coarse, and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Nb content is 0.005 to 0.060%.
  • the lower limit of the Nb content is preferably 0.008%, more preferably 0.010%.
  • the upper limit of the Nb content is preferably 0.055%, more preferably 0.050%, and even more preferably 0.045%.
  • Ti 0.005 to 0.030%
  • Ti is an element that combines with N (nitrogen) to form a nitride.
  • the nitride refines the crystal grains by the pinning effect. As a result, the SSC resistance and / or the SOHIC resistance of the steel material is enhanced. If the Ti content is too low, the above effect may not be obtained. On the other hand, if the Ti content is too high, the nitride may become coarse and the SSC resistance and / or SOHIC resistance of the steel material may decrease. Therefore, the Ti content is 0.005 to 0.030%.
  • the lower limit of the Ti content is preferably 0.006%, more preferably 0.007%, and even more preferably 0.008%.
  • the upper limit of the Ti content is preferably 0.025%, more preferably 0.020%, and even more preferably 0.017%.
  • Ca 0.0001 to 0.0040%
  • Ca is an element that controls the morphology of sulfides in steel materials and enhances SSC resistance and / or SOHIC resistance of steel materials. If the Ca content is too low, the above effect may not be obtained. On the other hand, if the Ca content is too high, coarse oxide-based inclusions may be formed, and the SSC resistance and / or SOHIC resistance of the steel material may decrease. Therefore, the Ca content is 0.0001 to 0.0040%.
  • the lower limit of the Ca content is preferably 0.0005%, more preferably 0.0010%.
  • the upper limit of the Ca content is preferably 0.0035%, more preferably 0.0030%.
  • Al 0 to 0.050%
  • Al is an arbitrary element. That is, the Al content may be 0% or more than 0%. If the Al content is too high, coarse oxide-based inclusions are formed, and the SSC resistance and / or SOHIC resistance of the steel material is lowered. Therefore, the Al content is 0 to 0.050%.
  • the upper limit of the Al content is preferably 0.045%, more preferably 0.040%.
  • Al is an element that deoxidizes steel. From the viewpoint of obtaining such an effect, the lower limit of the Al content is preferably 0.0005%, more preferably 0.0010%, and further preferably 0.0015%.
  • N is an element that combines with Ti to form fine nitrides to refine the crystal grains of the steel material and enhance the SSC resistance and SOHIC resistance of the steel material. If the N content is too low, the above effect may not be obtained. On the other hand, if the N content is too high, the nitride may become coarse and the SSC resistance and / or SOHIC resistance of the steel material may decrease. Therefore, the N content is 0.0010 to 0.0080%.
  • the lower limit of the N content is preferably 0.0015%, more preferably 0.0020%.
  • the upper limit of the N content is preferably 0.0070%, more preferably 0.0060%, and even more preferably 0.0050%.
  • O is an impurity.
  • the O content may be 0% or more than 0%.
  • O is an element that forms a coarse oxide and lowers the SSC resistance and / or the SOHIC resistance of the steel material. Therefore, the O content is 0.0030% or less.
  • the upper limit of the O content is preferably 0.0028%, more preferably 0.0025%.
  • the O content is preferably as low as possible. However, an extreme reduction in O content significantly increases the manufacturing cost of steel materials. Therefore, when considering industrial production, the lower limit of the O content is preferably 0.0001%, more preferably 0.0003%, still more preferably 0.0010%, still more preferably 0. It is 0015%.
  • Cu 0 to 0.500%
  • the Cu content may be 0% or more than 0%. If the Cu content is too high, the strength of the steel material may become too high, and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Cu content is 0 to 0.500%.
  • the upper limit of the Cu content is preferably 0.450%, more preferably 0.400%.
  • Cu is an element that dissolves in a steel material to increase the strength of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Cu content is preferably more than 0%, more preferably 0.010%, further preferably 0.020%, still more preferably 0.030%. be.
  • Ni is an optional element. That is, the Ni content may be 0% or more than 0%. If the Ni content is too high, the strength of the steel material may become too high, and the SSC resistance and SOHIC resistance of the steel material may decrease, and further, the electric sewing weldability of the steel material may decrease. Therefore, the Ni content is 0 to 0.500%.
  • the upper limit of the Ni content is preferably 0.450%, more preferably 0.400%.
  • Ni is an element that dissolves in a steel material to increase the strength of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Ni content is preferably more than 0%, more preferably 0.010%, further preferably 0.050%, still more preferably 0.100%. be.
  • B 0 to 0.0020%
  • B (boron) is an optional element. That is, the B content may be 0% or more than 0%. If the B content is too high, coarse nitrides may be formed, which may reduce the SSC resistance and SOHIC resistance of the steel material. Therefore, the B content is 0 to 0.0020%.
  • the upper limit of the B content is preferably 0.0015%, more preferably 0.0012%.
  • B is an element that dissolves in the steel material to increase the strength of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the content of B is preferably more than 0%, more preferably 0.0001%, further preferably 0.0002%, still more preferably 0.0003%. Is.
  • V 0 to 0.100%
  • V vanadium
  • the V content may be 0% or more than 0%. If the V content is too high, the low temperature toughness of the steel material may decrease. Therefore, the V content is 0 to 0.100%.
  • the upper limit of the V content is preferably 0.090%, more preferably 0.080%.
  • V is an element that forms a carbonitride or the like and enhances the strength of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the V content is preferably more than 0%, more preferably 0.001%, still more preferably 0.005%, still more preferably 0.010%. be.
  • Cr 0 to 0.500%
  • Cr is an arbitrary element. That is, the Cr content may be 0% or more than 0%. If the Cr content is too high, the SSC resistance of the steel material may decrease. Therefore, the Cr content is 0 to 0.500%.
  • the upper limit of the Cr content is preferably 0.450%, more preferably 0.400%.
  • Cr is an element that forms carbides to increase the strength of steel materials. From the viewpoint of obtaining such an effect, the lower limit of the Cr content is preferably more than 0%, more preferably 0.010%, further preferably 0.050%, still more preferably 0.100%. be.
  • Mo 0 to 0.500%
  • Mo is an arbitrary element. That is, the Mo content may be 0% or more than 0%. When Mo content is too high, M 2 C type carbides are excessively generated, it may decrease the SSC resistance of the steel. Therefore, the Mo content is 0 to 0.500%.
  • the upper limit of the Mo content is preferably 0.450%, more preferably 0.400%.
  • Mo is an element that forms carbides to increase the strength of steel materials. From the viewpoint of obtaining such an effect, the lower limit of the Mo content is preferably more than 0%, more preferably 0.010%, further preferably 0.050%, still more preferably 0.100%. be.
  • W 0 to 0.500%
  • W is an optional element. That is, the W content may be 0% or more than 0%. If the W content is too high, coarse carbides may be formed in the steel material, which may reduce the SSC resistance of the steel material. Therefore, the W content is 0 to 0.500%.
  • the upper limit of the W content is preferably 0.450%, more preferably 0.400%.
  • W is an element that increases the strength of the steel material. W is also an element that forms a protective corrosive film in a hydrogen sulfide environment, suppresses hydrogen intrusion, and as a result, enhances SSC resistance and SOHIC resistance of steel materials. From the viewpoint of obtaining these effects, the lower limit of the W content is preferably more than 0%, more preferably 0.001%, still more preferably 0.050%, still more preferably 0.100%. Is.
  • Zr 0-0.0500%
  • Zr is an arbitrary element. That is, the Zr content may be 0% or more than 0%. If the Zr content is too high, the oxide in the steel material may become coarse and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Zr content is 0-0.0500%.
  • the upper limit of the Zr content is preferably 0.0400%, more preferably 0.0300%.
  • Zr is an element that refines sulfide in the steel material and enhances the SSC resistance and SOHIC resistance of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Zr content is preferably more than 0%, more preferably 0.0001%, further preferably 0.0003%, still more preferably 0.0005%. be.
  • Ta 0-0.0500%
  • the Ta content may be 0% or more than 0%. If the Ta content is too high, the oxide in the steel material may become coarse and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Ta content is 0 to 0.0500%.
  • the upper limit of the Ta content is preferably 0.0400%, more preferably 0.0300%.
  • Ta is an element that refines sulfide in the steel material and enhances the SSC resistance and SOHIC resistance of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Ta content is preferably more than 0%, more preferably 0.0001%, further preferably 0.0003%, still more preferably 0.0005%. be.
  • Mg 0 to 0.0050%
  • Mg is an optional element. That is, the Mg content may be 0% or more than 0%. If the Mg content is too high, the oxide in the steel material may become coarse and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Mg content is 0 to 0.0050%.
  • the upper limit of the Mg content is preferably 0.0045%, more preferably 0.0040%.
  • Mg is an element that detoxifies S in the steel material as a sulfide and enhances the SSC resistance and SOHIC resistance of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Mg content is preferably more than 0%, more preferably 0.0001%, further preferably 0.0003%, still more preferably 0.0005%. be.
  • REM 0-0.0050% REM is an optional element. That is, the REM content may be 0% or more than 0%.
  • REM is selected from the group consisting of rare earth elements, that is, Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. It means at least one element to be produced.
  • the REM content means the total content of rare earth elements. If the REM content is too high, the oxide becomes coarse and the SSC resistance and SOHIC resistance of the steel material deteriorate. Therefore, the REM content is 0 to 0.0050%.
  • REM is an element that controls the morphology of sulfide in the steel material to enhance the SSC resistance and SOHIC resistance of the steel material.
  • REM is also an element that binds to P in the steel material and suppresses segregation of P at the grain boundaries, thereby suppressing a decrease in low temperature toughness of the steel material due to segregation of P.
  • the lower limit of the REM content is preferably more than 0%, more preferably 0.0001%, still more preferably 0.0003%, still more preferably 0.0005%. Is.
  • Hf 0 to 0.0050%
  • Hf is an arbitrary element. That is, the Hf content may be 0% or more than 0%. If the Hf content is too high, the oxide in the steel material may become coarse and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Hf content is 0 to 0.0050%.
  • the upper limit of the Hf content is preferably 0.0045%, more preferably 0.0040%.
  • Hf is an element that controls the morphology of sulfide in the steel material to enhance the SSC resistance and SOHIC resistance of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Hf content is preferably more than 0%, more preferably 0.0001%, further preferably 0.0003%, still more preferably 0.0005%. be.
  • Re 0-0.0050%
  • the Re content may be 0% or more than 0%. If the Re content is too high, the oxide in the steel material may become coarse and the SSC resistance and SOHIC resistance of the steel material may decrease. Therefore, the Re content is 0 to 0.0050%.
  • the upper limit of the Re content is preferably 0.0045%, more preferably 0.0040%.
  • Re is an element that controls the morphology of sulfide in the steel material and enhances the SSC resistance and SOHIC resistance of the steel material. From the viewpoint of obtaining such an effect, the lower limit of the Re content is preferably more than 0%, more preferably 0.0001%, further preferably 0.0003%, still more preferably 0.0005%. be.
  • Remaining part Fe and impurities
  • the balance excluding each element described above is Fe and impurities.
  • the impurity refers to a component contained in a raw material (for example, ore, scrap, etc.) or a component mixed in a manufacturing process and not intentionally contained in steel.
  • Impurities include any element other than the elements described above.
  • the element as an impurity may be only one kind or two or more kinds. Examples of impurities include Sb, Sn, Co, As, Pb, Bi, H (hydrogen) and the like.
  • Sb, Sn, Co, and As are mixed with a content of 0.1% or less
  • Pb and Bi are mixed with a content of 0.005% or less
  • H is mixed with a content of, for example, 0.005% or less.
  • contamination is 0.0004% or less. It is not necessary to control the content of other elements as long as it is within the normal range.
  • the chemical composition of the base metal is Cu: more than 0% and 0.500% or less, Ni: more than 0% and 0.500% or less, and B: more than 0% and 0.0020 from the viewpoint of obtaining the effect of each of the above-mentioned arbitrary elements.
  • V more than 0% and less than 0.100%
  • Cr more than 0% and less than 0.500%
  • Mo more than 0% and less than 0.500%
  • W more than 0% and less than 0.500%
  • Zr 0 % More than 0.0500% or less
  • Ta More than 0% and less than 0.0500%
  • Mg More than 0% and less than 0.0050%
  • REM More than 0% and less than 0.0050%
  • Hf More than 0% and 0.0050% It may contain one or more selected from the group consisting of the following and Re: more than 0% and 0.0050% or less.
  • the preferable ranges of the contents of these arbitrary elements are as described above.
  • the electrosewn steel pipe of the present disclosure has a polygonal ferrite fraction (hereinafter, also referred to as “F fraction”) of 80% or more and less than 100% in the metal structure of the inner surface layer of the base metal portion, and the balance is pseudo pearlite and Contains cementite.
  • the metallographic structure of the inner surface layer of the base metal portion has ⁇ YS and the above-mentioned chemical composition A, and the tensile strength of the base metal portion is in the range of 515 to 650 MPa. It is a metal structure that is a prerequisite for obtaining the effect of sour resistance (specifically, SSC resistance and SOHIC resistance) according to the requirement of ⁇ Hv.
  • the F fraction in the metal structure of the inner surface layer of the base metal portion is less than 80%, the strength of the base metal portion becomes too high and ⁇ YS and ⁇ Hv become too large, and as a result, the SSC resistance and SOHIC resistance of the steel material become too large. Sex may be reduced. Therefore, the F fraction in the metal structure of the inner surface layer of the base metal portion is 80% or more, preferably 83% or more, more preferably 85% or more, and further preferably 90% or more. If the F fraction in the metal structure of the inner surface layer of the base metal portion is 100%, the tensile strength and yield strength of the base metal portion may become too low. Therefore, the F fraction in the metal structure of the inner surface layer of the base metal portion is less than 100%, preferably 98% or less, and more preferably 95% or less.
  • the rest of the metal structure of the inner surface layer of the base metal portion excluding the polygonal ferrite contains pseudo pearlite and cementite.
  • the balance is preferably composed of pseudo-pearlite and cementite.
  • the measurement of the F fraction and the confirmation of the type of the remaining portion in the metal structure of the inner surface layer of the base metal portion are performed as follows.
  • L cross section that is, a cross section parallel to the pipe axial direction and the wall thickness direction of the power sewn steel pipe) at the 180 ° position of the base material in the power sewn steel pipe (that is, the position shifted by 180 ° in the pipe circumferential direction from the power sewn welded portion).
  • a metallographic photograph at a depth of 1 mm from the inner surface of the electrosewn steel pipe in the L cross section after the tital etching is taken with a scanning electron microscope (SEM) at a magnification of 200 times.
  • SEM scanning electron microscope
  • the electrosewn steel pipe of the present disclosure has a tensile strength (TS) of a base material portion of 515 to 650 MPa.
  • TS of the base material portion means the tensile strength in the pipe axis direction.
  • the TS of the base material portion is preferably 520 MPa or more, more preferably 530 MPa or more.
  • the SSC resistance and the SOHIC resistance of the base material portion are improved.
  • the TS of the base metal portion is preferably 640 MPa or less, more preferably 630 MPa or less.
  • the yield strength (YS) of the base metal portion of the electrosewn steel pipe of the present disclosure is 410 MPa or more.
  • YS of the base metal portion means the yield strength in the pipe axis direction.
  • the YS of the base material portion is preferably 430 MPa or more, more preferably 450 MPa or more.
  • the YS of the base material portion is preferably 630 MPa or less.
  • the YS of the base material portion is 630 MPa or less, it is advantageous in terms of SSC resistance and SOHIC resistance of the base material portion. Further, when the YS of the base material portion is 630 MPa or less, it is advantageous in terms of bending deformability or buckling suppression when laying a pipeline formed by using an electrosewn steel pipe for a line pipe.
  • the YS of the base material portion is more preferably 620 MPa or less, further preferably 610 MPa or less, and further preferably 600 MPa or less.
  • the TS of the base material and the YS of the base material are measured by the following method in accordance with ASTM E8 (2013).
  • a round bar test piece having a diameter of 6 mm and a parallel part length of 35 mm is obtained from the center of the wall thickness at the 180 ° position of the base metal of the electric resistance pipe. Collect in the direction parallel to the pipe axis direction.
  • a tensile test (that is, a tube axial tensile test) is carried out in the air at room temperature (25 ° C.) in accordance with ASTM E8 (2013).
  • the maximum stress during uniform elongation in the above tensile test is defined as TS (MPa) of the base metal portion.
  • the 0.2% proof stress in the above tensile test is defined as YS (MPa) of the base material portion.
  • the yield elongation is substantially not observed when the pipe axial tensile test (for example, the above-mentioned tensile test) is performed.
  • the fact that the yield elongation is substantially not observed means that the yield elongation is less than 1%.
  • the fact that the yield elongation is not substantially observed in the pipe axial tensile test of the base metal portion means that the electric pipe is an as-rolled electric pipe.
  • the azurol electric resistance pipe means an electric pipe that has not been subjected to a heat treatment other than the seam heat treatment after the pipe is made.
  • an electrosewn steel pipe that has been subjected to a heat treatment (for example, tempering) other than the seam heat treatment after the pipe is made has a substantial yield elongation (yield elongation of 1% or more) when a tensile test in the pipe axial direction is performed. Is observed.
  • the YR of the base metal portion means the yield ratio in the pipe axis direction.
  • the YR of the base metal portion is preferably 0.97 or less, more preferably 0.97 or less. It is 0.96 or less. Examples of the lower limit of YR of the base material portion include 0.85 and 0.86.
  • ⁇ YS (that is, a value obtained by subtracting the yield strength of the electric resistance welded portion from the yield strength of the base metal portion) is 0 to 80 MPa.
  • ⁇ YS is 0 to 80 MPa, the generation of SSC in the electric sewing welded portion is suppressed (that is, the SSC resistance in the electric sewing welded portion is improved).
  • ⁇ YS is 80 MPa or less, preferably 70 MPa or less.
  • the fact that ⁇ YS is 0 MPa or more contributes to the manufacturing suitability of the electrosewn steel pipe of the present disclosure.
  • the yield strength of the electric stitch welded portion is higher than the yield strength of the base metal portion.
  • the yield strength of the electric resistance welded portion is equal to or lower than the yield strength of the base metal portion (specifically, ⁇ YS is 0 MPa or more). Is).
  • the method for measuring the yield strength (YS) of the base metal portion for calculating ⁇ YS is as described above.
  • the yield strength (YS) of the electric stitch welded portion for calculating ⁇ YS is measured by the following method in accordance with ASTM E8 (2013).
  • a round bar test piece having a diameter of 6 mm and a parallel portion length of 35 mm is obtained from a region including an electrosewn welded portion on the inner surface side of the electrosewn steel pipe. Collect so that it is parallel to the circumferential direction of the pipe. More specifically, the round bar test piece is collected so that the center of the parallel portion in the round bar test piece in the longitudinal direction and the electric stitch welding abuttal line of the electric resistance pipe are substantially aligned with each other.
  • substantially the same means that the center of the parallel portion in the longitudinal direction and the electric resistance welding abuttal line of the electric resistance pipe are completely coincident with each other, or the deviation between the two is within 1 mm. ..
  • a tensile test that is, a tensile test in the circumferential direction of the tube
  • the 0.2% proof stress in the above tensile test is defined as YS (MPa) of the electric stitch welded portion.
  • ⁇ Hv (that is, the value obtained by subtracting the Vickers hardness of the inner surface layer of the electric sewing welded portion from the Vickers hardness of the outer surface layer of the electric sewing welded portion) is 0 to 25 Hv.
  • ⁇ Hv is 0 to 25 Hv, the generation of SOHIC in the electric stitch welded portion is suppressed (that is, the SOHIC resistance in the electric stitch welded portion is improved).
  • ⁇ YS is 0 to 80 MPa
  • ⁇ Hv is more than 25 Hv, SOHIC may occur in the electric stitch welded portion. Therefore, ⁇ Hv is 25 Hv or less, preferably 20 Hv, more preferably 18 Hv, and even more preferably 15 Hv.
  • ⁇ Hv is 0 Hv or more contributes to the manufacturing suitability of the electrosewn steel pipe of the present disclosure.
  • the Vickers hardness of the outer surface layer of the electrosewn welded portion is determined as follows. In the C cross section of the electric resistance pipe (that is, the cross section perpendicular to the pipe axis direction), it is on a line corresponding to a depth of 1 mm from the outer surface of the electric resistance pipe, and is centered on the electric resistance welding abutment line. Five points with a 0.5 mm pitch within a range of 2 mm in the circumferential direction of the pipe are specified as measurement points. At each of the five measurement points, the Vickers hardness is measured in accordance with JIS Z 2244 (2009) under the condition of a load of 100 gf. The arithmetic mean value of the measured values at the five measurement points is defined as "Vickers hardness of the outer surface layer of the electric stitch welded portion".
  • the Vickers hardness of the inner surface layer of the electrosewn welded portion is determined as follows.
  • the pitch is 0.5 mm on the line corresponding to the position of 1 mm in depth from the inner surface of the electric resistance welded steel pipe and within the range of 2 mm in the circumferential direction of the electric pipe centered on the electric resistance welding abuttal line. 5 points are specified as measurement points.
  • the Vickers hardness is measured in accordance with JIS Z 2244 (2009) under the condition of a load of 100 gf.
  • the arithmetic mean value of the measured values at the five measurement points is defined as "Vickers hardness of the inner surface layer of the electric stitch welded portion".
  • ⁇ Hv is the “Vickers hardness of the inner surface layer of the electric sewing welded portion” obtained as described above from the “Vickers hardness of the outer surface layer of the electric sewing welded portion” obtained as described above. Is calculated by subtracting.
  • ⁇ Thickness of electric resistance pipe> when the wall thickness of the electric pipe X (that is, the electric pipe satisfying the requirements other than the requirements of ⁇ YS and ⁇ Hv in the electric pipe of the present disclosure) is thick (specifically). It was found that when ⁇ YS is 13 mm or more, there is a strong tendency for ⁇ YS to take a large positive value, and there is a strong tendency for SSC to occur in the electric resistance welded portion.
  • the wall thickness of the electrosewn steel pipe of the present disclosure is preferably 13 mm or more, more preferably 14 mm or more, in that the effect of improving the sour resistance due to the requirements of ⁇ YS and ⁇ Hv is large.
  • the wall thickness of the electrosewn steel pipe of the present disclosure is preferably 25 mm or less, more preferably 23 mm or less, and further, from the viewpoint of further suppressing the occurrence of SSC in the electrosewn welded portion due to the thick wall thickness. It is preferably 20 mm or less.
  • the outer diameter of the electrosewn steel pipe of the present disclosure is not particularly limited, but is preferably 300 to 650 mm.
  • the outer diameter is more preferably 330 mm or more, still more preferably 350 mm or more.
  • the outer diameter is 650 mm or less, the manufacturing suitability of the electrosewn steel pipe is excellent.
  • the outer diameter is preferably 630 mm or less, more preferably 610 mm or less.
  • SSC resistance and SOHIC resistance of electrosewn steel pipe can be evaluated by a 4-point bending test. The details will be described below.
  • a mixed aqueous solution NACE solution A
  • a rectangular parallelepiped test piece having a length of 120 mm, a width of 10 mm, and a thickness of 2 mm is collected from a region including an electric stitch welded portion on the inner surface side of the electric resistance pipe.
  • the length direction of the test piece is the pipe circumferential direction of the electric resistance pipe
  • the width direction of the test piece is the pipe axial direction of the electric resistance pipe
  • the thickness direction of the test piece is the electric resistance steel pipe. Collect in the direction of the wall thickness.
  • the center of the rectangular parallelepiped test piece in the longitudinal direction and the electric resistance welding abuttal line of the electric resistance pipe are collected so as to be substantially coincident with each other.
  • substantially coincident means that the center in the longitudinal direction of the rectangular parallelepiped test piece and the electric resistance welding abuttal line of the electric resistance pipe are completely coincident with each other, or the deviation between the two is within 1 mm. Means.
  • a 4-point bending stress is applied to the collected rectangular parallelepiped test piece using a 4-point bending test jig in accordance with ASTM G39-99 (2011).
  • the load of the four-point bending stress is performed with the distance between the support points (that is, the distance between the outer support points) being 100 mm and the distance between the load points (that is, the distance between the inner support points) being 40 mm.
  • the four-point bending stress applied to the test piece is a stress corresponding to 90% of YS in the tube axial direction of the base metal portion.
  • the test piece with the 4-point bending stress applied is sealed in the test container together with the 4-point bending test jig.
  • test bath is injected into this test container leaving the gas phase portion, and the test piece is immersed in the test bath. Subsequently, after degassing the test bath, by stirring the test bath while continuously bubbling H 2 S gas 1 atm, to saturate the H 2 S gas in a test bath. Next, after sealing the test container, the test bath in which the test piece is immersed is held at 24 ° C. for 720 hours, and then the test piece is taken out. The test piece taken out is observed, and the presence or absence of SSC and SOHIC is determined. When neither SSC nor SOHIC is generated, it can be judged that the SSC resistance and the SOHIC resistance are excellent.
  • SSC and SOHIC are distinguished by the shape of the crack. Specifically, a crack extending in both the pipe axis direction and the wall thickness direction is referred to as SOHIC, and a crack extending in the wall thickness direction but not extending in the pipe axis direction is referred to as SSC.
  • manufacturing method A ⁇ Example of manufacturing method of electric resistance steel pipe (manufacturing method A)>
  • manufacturing method A an example of a manufacturing method for manufacturing the electric resistance welded steel pipe of the present disclosure (hereinafter, referred to as “manufacturing method A”) will be described.
  • the following manufacturing method A is a manufacturing method of an electrosewn steel pipe according to an embodiment described later.
  • Manufacturing method A is A slab preparation step for preparing a slab having a chemical composition A (that is, the chemical composition of the base metal portion in the present disclosure), A hot-rolling process in which the prepared slab is hot-rolled under the conditions described below to obtain a hot-rolled steel sheet, A hot-rolled steel sheet water-cooling process in which the hot-rolled steel sheet is water-cooled until the temperature of the outer surface of the hot-rolled steel sheet reaches a winding temperature of 450 to 625 ° C. A winding process for obtaining a hot coil made of a hot-rolled steel sheet by winding the cooled hot-rolled steel sheet at the above-mentioned winding temperature.
  • a hot-rolling process in which the prepared slab is hot-rolled under the conditions described below to obtain a hot-rolled steel sheet
  • a hot-rolled steel sheet water-cooling process in which the hot-rolled steel sheet is water-cooled until the temperature of the outer surface of the hot-rolled steel sheet reaches a winding temperature of 450 to 625 ° C.
  • a hot-rolled steel sheet is unwound from a hot coil, and the unwound hot-rolled steel sheet is roll-formed to form an open pipe, and the abutting portion of the obtained open pipe is electrosewn to form an electrosewn welded portion.
  • the pipe making process to obtain the raw pipe by The electric-sewn welded part of the raw pipe is heated to a heating temperature of 900 to 1000 ° C., soaked at the above heating temperature for 1 second or longer, and then to a cooling stop temperature of 300 to 580 ° C., 5 to 20 ° C./sec.
  • Seam heat treatment process that performs seam heat treatment to cool with water at the cooling rate of including.
  • the raw pipe means an electro-sewn steel pipe before the seam heat treatment is applied to the electro-sewn welded portion.
  • the electrosewn steel pipe of the present disclosure can be manufactured.
  • each step in the manufacturing method A will be described.
  • the slab preparation step in the production method A is a step of preparing a slab having the above-mentioned chemical composition.
  • the step of preparing the slab may be a step of manufacturing the slab, or may be a step of simply preparing the slab that has been manufactured in advance.
  • a molten steel having the above-mentioned chemical composition is produced, and the produced molten steel is used to produce a slab.
  • a slab may be produced by a continuous casting method, or an ingot may be produced using molten steel, and the ingot may be lump-rolled to produce a slab.
  • the hot-rolling step in the manufacturing method A is a step of heating the slab prepared above and hot-rolling the heated slab to obtain a hot-rolled steel sheet.
  • the slab heating temperature when heating the slab is 1100 to 1250 ° C.
  • the heating temperature is 1100 ° C. or higher, the refinement of crystal grains during hot rolling and the precipitation strengthening after hot rolling are more likely to proceed, and as a result, the strength of steel is more likely to be improved.
  • the heating temperature is 1250 ° C. or lower, the coarsening of the austenite grains can be further suppressed, so that the crystal grains can be easily refined, and as a result, the strength of the steel can be further improved.
  • the slab is heated by, for example, a heating furnace.
  • the slab heating temperature means the temperature of the outer surface of the slab.
  • the slab heated above is hot-rolled to obtain a hot-rolled steel sheet.
  • the hot rolling is preferably performed under the condition that the finish rolling end temperature (hereinafter, also referred to as “finish rolling temperature”) is 780 to 930 ° C.
  • Hot rolling is generally performed using a rough rolling mill and a finishing rolling mill. Both the rough rolling mill and the finishing rolling mill generally have a plurality of rolling stands arranged in a row, and each rolling stand has a roll pair.
  • the finish rolling temperature (that is, the finish rolling end temperature) is the surface temperature of the hot-rolled steel sheet on the outlet side of the final stand of the finish rolling machine.
  • the finish rolling temperature is 780 ° C. or higher, the rolling resistance of the steel sheet can be reduced, so that the productivity is improved. Further, when the finish rolling temperature is 780 ° C. or higher, the phenomenon of rolling in the two-phase region of ferrite and austenite is suppressed, and the formation of a layered structure and the deterioration of mechanical properties due to this phenomenon can be suppressed. On the other hand, when the finish rolling temperature is 930 ° C. or lower, the phenomenon that the hot-rolled steel sheet becomes too hard is suppressed, so that the phenomenon that the TS of the base material portion of the obtained electro-sewn steel pipe becomes too high is suppressed.
  • the hot-rolled steel sheet water-cooling step is a step of water-cooling the hot-rolled steel sheet until the temperature of the outer surface of the hot-rolled steel sheet reaches a winding temperature of 450 to 625 ° C.
  • the winding temperature (that is, the cooling end temperature of the outer surface of the hot-rolled steel sheet) is 450 ° C. or higher.
  • the winding temperature is preferably 500 ° C. or higher.
  • the winding temperature is preferably 600 ° C. or lower.
  • a hot-rolled steel sheet is unwound from a hot coil, and the unwound hot-rolled steel sheet is roll-formed to form an open pipe.
  • This is a step of obtaining a raw pipe (that is, an electro-sewn steel pipe before the seam heat treatment is applied to the electro-sewn welded portion) by forming the portion.
  • the seam heat treatment step in the manufacturing method A is a step of performing a seam heat treatment on the electric resistance welded portion of the raw pipe (that is, the electric resistance welded steel pipe before the seam heat treatment is applied to the electric resistance welded portion).
  • the electric sewing welded portion in the raw pipe is heated to a heating temperature of 900 to 1000 ° C., soaked at the above heating temperature for 1 second or more, and then to a cooling stop temperature of 300 to 580 ° C. It is a process of water cooling at a cooling rate of 5 to 20 ° C./sec. After water cooling, air cool until the temperature of the electrosewn weld reaches room temperature.
  • the seam heat treatment in the manufacturing method A is performed by heating and cooling the electric sewing welded portion before the seam heat treatment from the outer surface side of the electric sewing welded portion in this order. More specifically, the seam heat treatment in the production method A is performed as follows. First, the electrosewn welded portion before the seam heat treatment is heated from the outer surface side by induction heating until the temperature of the outer surface reaches a heating temperature in the range of 900 to 1000 ° C., and the temperature of the outer surface is heated in the above range. The heat is equalized by holding the temperature in the state of the temperature for an equalizing time in the range of 1 second or more (preferably 1 second to 5 seconds).
  • the electrosewn welded portion after heat equalization is water-cooled from the outer surface side at a cooling rate in the range of 5 to 20 ° C./sec to a cooling shutdown temperature in the range of 300 to 580 ° C.
  • a cooling rate in the range of 5 to 20 ° C./sec the water-cooled shower is made into a mist, the flow rate of the water-cooled shower is adjusted, and the angle of the water-cooled shower is adjusted. And so on.
  • the heating temperature is the temperature of the outer surface of the electric sewing welded portion
  • the cooling rate is the cooling rate on the outer surface of the electric sewing welded portion.
  • the cooling stop temperature is the reheat temperature after stopping the water cooling, which is measured on the outer surface of the electric sewing welded portion, and is the maximum temperature measured within 1 minute after the water cooling is stopped.
  • the heating temperature in the seam heat treatment step of the production method A is 900 ° C. or higher.
  • the heating temperature in the seam heat treatment step in the production method A is 1000 ° C. or lower.
  • the cooling shutdown temperature in the seam heat treatment step of the production method A is 300 ° C. or higher.
  • the cooling shutdown temperature in the seam heat treatment step when the cooling shutdown temperature is more than 580 ° C., the YS of the electric stitch welded portion tends to be too low, and the ⁇ YS tends to be more than 80 MPa.
  • the cooling shutdown temperature in the seam heat treatment step of the production method A is 580 ° C. or lower.
  • the cooling rate in the seam heat treatment step of the production method A is 5 ° C./sec or more.
  • the cooling rate in the seam heat treatment step of the production method A is 20 ° C./sec or less.
  • the production method A may include other steps other than the above-mentioned steps.
  • Other steps include a step of adjusting the shape of the electrosewn steel pipe with a sizing roll after the seam heat treatment step.
  • Each step in manufacturing method A does not affect the chemical composition of steel. Therefore, by using a molten steel or a slab having a chemical composition A, an electrosewn steel pipe having a chemical composition of the base material portion A is manufactured.
  • the underline in Tables 1 to 3 means that the pipe is out of the range of the electric resistance welded steel pipe of the present disclosure or is out of the range of the manufacturing method A.
  • Test numbers 1 to 22 are examples, and test numbers 23 to 43 are comparative examples.
  • the above slab is heated in a heating furnace, and the heated slab is hot-rolled using a plurality of hot-rolled mills to obtain a hot-rolled steel sheet, and the obtained hot-rolled steel sheet is water-cooled to obtain a water-cooled hot-rolled steel sheet.
  • a hot coil made of hot-rolled steel sheet was obtained.
  • the heating temperature when heating the slab is set to 1200 ° C.
  • the finish rolling temperature in hot rolling is 790 ° C to 930 ° C.
  • the winding temperature was 500 ° C. to 600 ° C.
  • the soaking time in the seam heat treatment was adjusted to be 1 second to 5 seconds.
  • the soaking time was controlled by adjusting the timing of starting the shower from the end of heating.
  • the cooling rate in the seam heat treatment was controlled by making the water-cooled shower mist and adjusting the flow rate and / or the angle of the water-cooled shower.
  • the cooling shutdown temperature in the seam heat treatment was controlled by adjusting the timing at which the shower was stopped.
  • the chemical composition of the base material portion of the obtained electrosewn steel pipe can be regarded as the same as the chemical composition of the molten steel which is the raw material.
  • the chemical composition of the base metal portion is the above-mentioned chemical composition A, and the chemical composition is the above-mentioned chemical composition A.
  • the F fraction is 80% or more and less than 100%, and the balance contains pseudo pearlite and cementite.
  • the YS of the base material is 410 MPa or more, and the TS of the base material is 515 to 650 MPa.
  • ⁇ YS which is the value obtained by subtracting the YS of the electric sewing welded portion from the YS of the base metal portion, is 0 to 80 MPa.
  • ⁇ Hv which is the value obtained by subtracting the Vickers hardness of the inner surface layer of the electric stitch welded portion from the Vickers hardness of the outer surface layer of the electric stitch welded portion, is 0 to 25 Hv.
  • the electric resistance pipes of Examples were excellent in SSC resistance and SOHIC resistance in the electric resistance welded portion.
  • the electric resistance pipe of test number 23 had an appropriate chemical composition of the base material (that is, the above-mentioned chemical composition A), the heating temperature in the seam heat treatment step was too high. As a result, the YS of the electric stitch welded portion became too high, and the ⁇ YS became less than 0 MPa. Further, the Vickers hardness of the outer surface layer of the electric stitch welded portion became too hard, and ⁇ Hv became more than 25 Hv. As a result, SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the chemical composition of the base metal portion was appropriate (that is, the chemical composition A described above)
  • the heating temperature in the seam heat treatment step was too low.
  • the YS of the electric stitch welded portion became too low, and the ⁇ YS became more than 80 MPa.
  • the Vickers hardness of the inner surface layer of the electric stitch welded portion was insufficient, and ⁇ Hv became more than 25 Hv.
  • SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the electric resistance welded steel pipe of test number 29 had a C content that was too low in the chemical composition of the base material.
  • the YS of the base material portion was less than 410 MPa, and the TS of the base material portion was less than 515 MPa.
  • the electric resistance welded steel pipe of test number 30 had an excessively high C content in the chemical composition of the base material.
  • the F fraction in the metal structure of the inner surface layer of the base material portion was less than 80%, and the TS of the base material portion exceeded 650 MPa.
  • the YS of the base metal portion became too high, and the ⁇ YS became more than 80 MPa.
  • the Vickers hardness of the outer surface layer of the electric stitch welded portion became too hard, and ⁇ Hv became more than 25 Hv.
  • SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the Mn content of the electrosewn steel pipe of test number 31 was too low in the chemical composition of the base metal part.
  • the YS of the base material portion was less than 410 MPa, and the TS of the base material portion was less than 515 MPa.
  • the electric resistance welded steel pipe of test number 32 had an excessively high Mn content in the chemical composition of the base material.
  • the base material TS was more than 650 MPa.
  • the YS of the base metal portion became too high, and the ⁇ YS became more than 80 MPa.
  • the Vickers hardness of the outer surface layer of the electric stitch welded portion became too hard, and ⁇ Hv became more than 25 Hv.
  • SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the electric resistance pipe of test number 33 had an excessively high P content in the chemical composition of the base material. As a result, SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the electric resistance welded steel pipe of test number 34 had an S content that was too high in the chemical composition of the base metal part. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electrolytically sewn steel pipe of test number 35 had an excessively high Si content in the chemical composition of the base material. As a result, SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the Nb content of the electrosewn steel pipe of test number 36 was too low in the chemical composition of the base metal part. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electric resistance welded steel pipe of test number 37 had an excessively high Nb content in the chemical composition of the base material. As a result, SSC and SOHIC were confirmed in the 4-point bending test. That is, excellent SSC resistance and SOHIC resistance could not be obtained.
  • the electric resistance steel pipe of test number 38 had a Ti content that was too low in the chemical composition of the base material. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electric resistance pipe of test number 39 had an excessively high Ti content in the chemical composition of the base material. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electric resistance steel pipe of test number 40 had an excessively high Ca content in the chemical composition of the base material. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electro-sewn steel pipe of test number 41 had an Al content that was too high in the chemical composition of the base material. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electric resistance welded steel pipe of test number 42 had an N content too high in the chemical composition of the base metal part. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.
  • the electric resistance pipe of test number 43 had an O content too high in the chemical composition of the base material. As a result, SOHIC was confirmed in the 4-point bending test. That is, excellent SOHIC resistance could not be obtained.

Abstract

Tube en acier soudé par résistance électrique à usage de tube de canalisation comprenant une partie de matériau parent et une partie soudée par résistance électrique, la partie de matériau parent ayant une composition chimique comprenant, en pourcentage en masse, de 0,030 à 0,090 % de C, de 0,01 à 0,50 % de Si, de 0,50 à 1,50 % de Mn, de 0,005 à 0,060 % de Nb, de 0,005 à 0 030 % de Ti, de 0,0001 à 0,0040 % de Ca et de 0,0010 à 0,0080 % de N, le reste comprenant du Fe et des impuretés. Le tube en acier soudé par résistance électrique à usage de tube de canalisation a un ΔYS de 0 à 80 MPa, cette valeur étant obtenue en soustrayant la limite d'élasticité de la partie soudée par résistance électrique de la limite d'élasticité de la partie de matériau parent, et une ΔHv de 0 à 25 Hv, cette valeur étant obtenue en soustrayant la dureté Vickers de la couche de surface interne dans la partie soudée par résistance électrique de la dureté Vickers de la couche de surface externe dans la partie soudée par résistance électrique.
PCT/JP2020/005072 2020-02-10 2020-02-10 Tube en acier soudé par résistance électrique à usage de tube de canalisation WO2021161366A1 (fr)

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EP20919182.4A EP4066954A4 (fr) 2020-02-10 2020-02-10 Tube en acier soudé par résistance électrique à usage de tube de canalisation
KR1020227021826A KR20220105166A (ko) 2020-02-10 2020-02-10 라인파이프용 전봉 강관
JP2021577721A JP7226595B2 (ja) 2020-02-10 2020-02-10 ラインパイプ用電縫鋼管
PCT/JP2020/005072 WO2021161366A1 (fr) 2020-02-10 2020-02-10 Tube en acier soudé par résistance électrique à usage de tube de canalisation

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Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0641684A (ja) 1992-07-27 1994-02-15 Nippon Steel Corp 耐硫化物応力腐食割れ性に優れた電縫鋼管
JPH06235045A (ja) 1993-02-10 1994-08-23 Nippon Steel Corp 耐硫化物応力腐食割れ性に優れた電縫鋼管
CN107988547A (zh) * 2016-10-27 2018-05-04 鞍钢股份有限公司 一种高频电阻焊管用x52ms热轧卷板及其制造方法
WO2018179169A1 (fr) * 2017-03-29 2018-10-04 新日鐵住金株式会社 Tuyau en acier soudé par résistance électrique de type brut de laminage pour tuyaux de canalisation
WO2018181564A1 (fr) * 2017-03-30 2018-10-04 Ｊｆｅスチール株式会社 Tôle d'acier haute résistance pour tuyau de canalisation résistant à l'acidité, son procédé de fabrication, et tuyau en acier haute résistance utilisant une tôle d'acier haute résistance pour tuyau de canalisation résistant à l'acidité
JP2018168441A (ja) * 2017-03-30 2018-11-01 Ｊｆｅスチール株式会社 耐サワーラインパイプ用高強度鋼板およびその製造方法並びに耐サワーラインパイプ用高強度鋼板を用いた高強度鋼管
WO2019132179A1 (fr) * 2017-12-26 2019-07-04 주식회사 포스코 Feuille d'acier laminée à chaud à haute résistance et haute robustesse et son procédé de fabrication
JP6575734B1 (ja) * 2019-03-04 2019-09-18 日本製鉄株式会社 ラインパイプ用電縫鋼管
JP6587041B1 (ja) * 2019-02-19 2019-10-09 日本製鉄株式会社 ラインパイプ用電縫鋼管

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2832021C (fr) * 2011-08-23 2014-11-18 Nippon Steel & Sumitomo Metal Corporation Tube d'acier soude par resistance electrique a paroi epaisse et procede de fabrication de ce dernier
JP5516659B2 (ja) * 2012-06-28 2014-06-11 Ｊｆｅスチール株式会社 中温域の長期耐軟化性に優れた高強度電縫鋼管及びその製造方法
JP2015190026A (ja) * 2014-03-28 2015-11-02 Ｊｆｅスチール株式会社 ラインパイプ用厚肉高強度電縫鋼管およびその製造方法
CA2962370C (fr) * 2014-09-25 2019-07-02 Jfe Steel Corporation Bande d'acier pour tuyau d'acier soude par resistance electrique, tuyau d'acier soude par resistance electrique, et procede de production de bande d'acier pour tuyau d'acier soudepar resistance electrique
CN108368582A (zh) * 2016-03-22 2018-08-03 新日铁住金株式会社 线管用电焊钢管
JP6260757B1 (ja) * 2017-06-22 2018-01-17 新日鐵住金株式会社 ラインパイプ用アズロール電縫鋼管及び熱延鋼板

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0641684A (ja) 1992-07-27 1994-02-15 Nippon Steel Corp 耐硫化物応力腐食割れ性に優れた電縫鋼管
JPH06235045A (ja) 1993-02-10 1994-08-23 Nippon Steel Corp 耐硫化物応力腐食割れ性に優れた電縫鋼管
CN107988547A (zh) * 2016-10-27 2018-05-04 鞍钢股份有限公司 一种高频电阻焊管用x52ms热轧卷板及其制造方法
WO2018179169A1 (fr) * 2017-03-29 2018-10-04 新日鐵住金株式会社 Tuyau en acier soudé par résistance électrique de type brut de laminage pour tuyaux de canalisation
WO2018181564A1 (fr) * 2017-03-30 2018-10-04 Ｊｆｅスチール株式会社 Tôle d'acier haute résistance pour tuyau de canalisation résistant à l'acidité, son procédé de fabrication, et tuyau en acier haute résistance utilisant une tôle d'acier haute résistance pour tuyau de canalisation résistant à l'acidité
JP2018168441A (ja) * 2017-03-30 2018-11-01 Ｊｆｅスチール株式会社 耐サワーラインパイプ用高強度鋼板およびその製造方法並びに耐サワーラインパイプ用高強度鋼板を用いた高強度鋼管
WO2019132179A1 (fr) * 2017-12-26 2019-07-04 주식회사 포스코 Feuille d'acier laminée à chaud à haute résistance et haute robustesse et son procédé de fabrication
JP6587041B1 (ja) * 2019-02-19 2019-10-09 日本製鉄株式会社 ラインパイプ用電縫鋼管
JP6575734B1 (ja) * 2019-03-04 2019-09-18 日本製鉄株式会社 ラインパイプ用電縫鋼管

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP4066954A4

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EP4066954A4 (fr) 2023-07-05

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