WO2014192251A1 - Tube en acier sans soudure destiné à un tube de canalisation utilisé dans un environnement acide - Google Patents

Tube en acier sans soudure destiné à un tube de canalisation utilisé dans un environnement acide Download PDF

Info

Publication number
WO2014192251A1
WO2014192251A1 PCT/JP2014/002662 JP2014002662W WO2014192251A1 WO 2014192251 A1 WO2014192251 A1 WO 2014192251A1 JP 2014002662 W JP2014002662 W JP 2014002662W WO 2014192251 A1 WO2014192251 A1 WO 2014192251A1
Authority
WO
WIPO (PCT)
Prior art keywords
seamless steel
steel pipe
content
less
pipe
Prior art date
Application number
PCT/JP2014/002662
Other languages
English (en)
Japanese (ja)
Inventor
小林　憲司
勇次 荒井
Original Assignee
新日鐵住金株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 新日鐵住金株式会社 filed Critical 新日鐵住金株式会社
Priority to CN201480031110.2A priority Critical patent/CN105283572B/zh
Priority to MX2015016413A priority patent/MX2015016413A/es
Priority to EP14803329.3A priority patent/EP3006585B8/fr
Priority to JP2015519628A priority patent/JP5915818B2/ja
Publication of WO2014192251A1 publication Critical patent/WO2014192251A1/fr
Priority to SA515370210A priority patent/SA515370210B1/ar

Links

Images

Classifications

    • 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
    • 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
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—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
    • C22C38/12—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
    • 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
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/54—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
    • C21D2211/005—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

  • the present invention relates to a seamless steel pipe. More preferably, the present invention relates to a seamless steel pipe for a line pipe used in a sour environment containing hydrogen sulfide (H 2 S) which is a corrosive gas.
  • H 2 S hydrogen sulfide
  • Crude oil and natural gas contain hydrogen sulfide and moisture.
  • a wet hydrogen sulfide environment is called a sour environment.
  • Line pipes are used as pipelines for transporting crude oil and natural gas produced from oil and gas wells. Therefore, the line pipe is used in a sour environment.
  • hydrogen embrittlement due to hydrogen that has penetrated into steel becomes a problem due to corrosion in an environment containing hydrogen sulfide.
  • Hydrogen embrittlement includes sulfide stress cracking that occurs in steel under static external stress, and hydrogen-induced cracking (hereinafter referred to as HIC) that occurs inside steel without external stress.
  • HIC hydrogen-induced cracking
  • line pipes HIC is often a problem. Therefore, the steel pipe for line pipes is particularly required to have HIC resistance.
  • the welded steel pipe has a seam portion (welded portion) extending in the axial direction or spiral shape.
  • a steel plate used for a welded steel pipe has a central segregation portion generated at the time of continuous casting in the center of the plate thickness, and the central segregation portion has high HIC sensitivity. Therefore, it is preferable to use a seamless steel pipe for a steel pipe for a line pipe that particularly requires HIC resistance.
  • Patent Document 1 proposes a seamless steel pipe having high strength and excellent HIC resistance.
  • the steel for line pipe disclosed in Patent Document 1 has a composition of mass%, C: 0.03 to 0.15%, Si: 0.05 to 1.0%, Mn: 0 .5 to 1.8%, P: 0.015% or less, S: 0.04% or less, O: 0.01% or less, N: 0.007% or less, sol. Al: 0.01% to 0.1%, Ti: 0.024% or less, Ca: 0.0003% to 0.02%, with the balance being Fe and impurities. Furthermore, in the steel material for line pipes, the size of TiN in the steel is 30 ⁇ m or less. Patent Document 1 describes that excellent HIC resistance can be obtained because TiN is fine.
  • the strength of the seamless steel pipe is usually increased by performing quenching and tempering treatment after the hot working process.
  • a low-strength seamless steel pipe for line pipes that does not require high strength and has a yield strength of less than 450 MPa.
  • Such a low-strength seamless steel pipe is usually not subjected to quenching and tempering and is omitted.
  • Blister is a bulge that occurs near the surface of a steel material and extends in the axial direction of the steel material.
  • HIC resistance test NACE TM0284, etc.
  • the occurrence of blisters may be confirmed even in high-strength seamless steel pipes exhibiting excellent HIC resistance.
  • HIC blister
  • An object of the present invention is to provide a seamless steel pipe that can suppress the generation of blisters and minute internal cracks when it is used for a line pipe used in a sour environment without quenching and tempering. is there.
  • the seamless steel pipe according to this embodiment is a line pipe application used in a sour environment.
  • the above seamless steel pipe is in mass%, C: 0.08 to 0.24%, Si: 0.10 to 0.50%, Mn: 0.3 to 2.5%, P: 0.02% or less S: 0.006% or less, Nb: 0.02 to 0.12%, Al: 0.005 to 0.100%, Ca: 0.0003 to 0.0050%, N: 0.0100% or less, O: 0.0050% or less, Ti: 0-0.1%, V: 0-0.03%, Cr: 0-0.6%, Mo: 0-0.3%, Ni: 0-0.
  • the balance comprising a chemical composition composed of Fe and impurities, and a structure composed of ferrite and pearlite, It has a yield strength of less than 450 MPa.
  • the seamless steel pipe of this embodiment can suppress the occurrence of blisters and minute internal cracks even if it is low strength without quenching and tempering.
  • FIG. 1 is a diagram showing the relationship between the yield strength of a seamless steel pipe and the number of blisters generated (pieces / 20 cm 2 ).
  • FIG. 2 is a photographic image of two surfaces (corresponding to the outer and inner surfaces of a seamless steel pipe) of the coupon test piece after the blister count measurement test of the inventive example (steel A4, thickness 20 mm) in the examples.
  • FIG. 3 is a photographic image of two surfaces (corresponding to an outer surface and an inner surface of a seamless steel pipe) of a coupon test piece after a blister number measurement test of a comparative example (steel B3, thickness 20 mm) in the examples.
  • the present inventors investigated and examined the occurrence of blisters in a low-strength seamless steel pipe that was not quenched and tempered, and obtained the following knowledge.
  • Blister occurs by the following mechanism. Hydrogen accumulates around the inclusions in the steel and forms the starting point for hydrogen blisters. When the steel material yields by increasing the starting hydrogen pressure, a crack is generated. When a crack is generated, dislocations and hydrogen are further accumulated at the crack tip, and the crack progresses. This produces a blister.
  • FIG. 1 is a diagram showing the relationship between the yield strength of a seamless steel pipe and the number of blisters generated (pieces / 20 cm 2 ).
  • FIG. 1 was obtained by the following method. Seamless steel pipes with various chemical compositions were produced. At this time, the seamless steel pipe after hot working was allowed to cool or cooled at a cooling rate of less than 5 ° C./s, and quenching and tempering were not performed.
  • a yield strength test described below was performed on each manufactured seamless steel pipe to determine the yield strength. Further, a blister number measurement test described later was performed to determine the number of blisters (pieces / 20 cm 2 ) generated in each seamless steel pipe, and FIG. 1 was created.
  • the number of blisters was remarkably reduced as the yield strength increased until the yield strength reached 350 MPa.
  • the yield strength was 350 MPa or more, the number of blisters did not change so much even if the yield strength increased.
  • the curve in FIG. 1 has an inflection point where the yield strength is around 350 MPa. Therefore, if the yield strength is 350 MPa or more, the number of blisters can be kept low.
  • the strength of the seamless steel pipe can be increased by quenching and tempering.
  • the quenching and tempering are performed, the manufacturing cost is increased.
  • the C content is increased and the Nb content is further increased.
  • the C content is 0.08 to 0.24%
  • the Nb content is 0.02 to 0.12%.
  • the numerical value of the Nb content is set to be equal to or higher than the F1 value defined by the formula (1).
  • F1 0.02 + (t ⁇ 15) ⁇ 0.001 (1)
  • a numerical value excluding the unit of the thickness (unit: mm) of the seamless steel pipe is substituted for t.
  • the wall thickness of seamless steel pipes used in sour environments for line pipes is, for example, 10 to 50 mm. As the wall thickness increases, the cooling conditions of the seamless steel pipe after hot working also change. That is, the cooling rate becomes slow and the strength of the steel tends to decrease. If the Nb content is equal to or greater than the F1 value of the formula (1), the strength of the steel becomes 350 MPa or more, and the generation of blisters can be suppressed.
  • the seamless steel pipe of the present embodiment completed based on the above knowledge is as follows.
  • the seamless steel pipe according to this embodiment is a line pipe application used in a sour environment.
  • the above seamless steel pipe is in mass%, C: 0.08 to 0.24%, Si: 0.10 to 0.50%, Mn: 0.3 to 2.5%, P: 0.02% or less S: 0.006% or less, Nb: 0.02 to 0.12%, Al: 0.005 to 0.100%, Ca: 0.0003 to 0.0050%, N: 0.0100% or less, O: 0.0050% or less, Ti: 0-0.1%, V: 0-0.03%, Cr: 0-0.6%, Mo: 0-0.3%, Ni: 0-0.
  • the balance comprising a chemical composition composed of Fe and impurities, and a structure composed of ferrite and pearlite, It has a yield strength of less than 450 MPa.
  • the content (% by mass) of Nb is not less than the F1 value defined by the formula (1).
  • F1 0.02 + (t ⁇ 15) ⁇ 0.001 (1)
  • a numerical value excluding the unit of the thickness (unit: mm) of the seamless steel pipe is substituted for t.
  • the seamless steel pipe according to this embodiment has the following chemical composition.
  • Carbon (C) increases the hardenability and increases the strength of the steel.
  • heat treatment such as quenching and tempering is not performed after pipe making as in the seamless steel pipe of this embodiment
  • the strength of the steel becomes too low.
  • the C content is too low, it is difficult to obtain excellent HIC resistance.
  • the C content is 0.08% or more, high-strength pearlite is dispersed and precipitated in the steel. Therefore, the yield of ferrite is suppressed. Therefore, excellent HIC resistance is obtained, and the generation of blisters is suppressed.
  • the seamless steel pipe of this embodiment is circumferentially welded as a line pipe on site.
  • the C content is 0.08 to 0.24%.
  • the minimum with preferable C content is higher than 0.08%, More preferably, it is 0.10%.
  • the upper limit with preferable C content is less than 0.24%, More preferably, it is 0.15%.
  • Si 0.10 to 0.50% Silicon (Si) deoxidizes steel. If the Si content is too low, this effect cannot be obtained. On the other hand, if the Si content is too high, the toughness of the weld heat affected zone decreases. If the Si content is too high, the precipitation of ferrite, which is a softening phase, is further promoted. For this reason, the HIC resistance is lowered, and blisters are easily generated. Therefore, the Si content is 0.10 to 0.50%.
  • the minimum with preferable Si content is higher than 0.10%, More preferably, it is 0.15%, More preferably, it is 0.20%.
  • the upper limit with preferable Si content is less than 0.50%, More preferably, it is 0.35%, More preferably, it is 0.30%.
  • Mn 0.3 to 2.5%
  • Manganese (Mn) increases the hardenability of the steel and increases the strength of the steel. Mn further increases the toughness of the steel. If the Mn content is too low, this effect cannot be obtained. On the other hand, if the Mn content is too high, HIC tends to occur due to hardening of the steel by Mn segregation and formation of MnS. Therefore, the Mn content is 0.3 to 2.5%.
  • the minimum with preferable Mn content is higher than 0.3%, More preferably, it is 0.5%, More preferably, it is 0.8%.
  • the upper limit with preferable Mn content is less than 2.5%, More preferably, it is 2.0%, More preferably, it is 1.8%.
  • P 0.02% or less Phosphorus (P) is an impurity. P decreases the toughness of the steel. Therefore, the P content is 0.02% or less.
  • the preferable P content is less than 0.02%, more preferably 0.01% or less.
  • the P content is preferably as low as possible.
  • S 0.006% or less Sulfur (S) is an impurity. S forms MnS. MnS becomes the starting point of the blister. Accordingly, a lower S content is preferable. However, reducing the S content is costly. In the seamless steel pipe of the present embodiment, the S content may be 0.006% or less in order to reduce the manufacturing cost. In the seamless steel pipe of this embodiment, even if the S content is 0.005% or more, if the C content and the Nb content are appropriate, excellent HIC resistance is exhibited, and blistering is suppressed. Is done. However, a lower S content is preferred. A preferable S content is 0.003% or less.
  • Nb 0.02 to 0.12% Niobium (Nb) is dissolved in ferrite to increase the strength of the steel. Nb further combines with C and N to form carbonitrides and refines the steel by pinning hardening. Refinement improves the HIC resistance of the steel. Refinement further increases the toughness of the steel.
  • a steel material containing C in the above range and Mn in the above range and containing no Nb is made into a seamless steel pipe and then heat treatment is not performed (that is, an as-roll in which quenching and tempering are omitted) When the material is manufactured), the yield strength of the manufactured seamless steel pipe is about 250 MPa.
  • the Nb content is in the above range, the yield strength of the seamless steel pipe increases to 350 MPa or more. Therefore, the generation of blisters is suppressed. If the Nb content is too low, the above effect cannot be obtained. On the other hand, if the Nb content is too high, coarse Nb carbonitride is formed. Coarse Nb carbonitride serves as a starting point for blisters and further reduces HIC resistance. Therefore, the Nb content is 0.02 to 0.12%.
  • the thickness of a seamless steel pipe for use in a line pipe in a sour environment is 10 to 50 mm.
  • F1 0.02 + (t ⁇ 15) ⁇ 0.001 (1)
  • a numerical value excluding the unit of the thickness (mm) of the seamless steel pipe is substituted for t in the formula (1).
  • the preferable lower limit of the Nb content is higher than 0.02%, more preferably 0.03%, and further preferably 0.04%.
  • the upper limit with preferable Nb content is less than 0.12%, More preferably, it is 0.10%, More preferably, it is 0.08%.
  • Al 0.005 to 0.100%
  • Aluminum (Al) deoxidizes steel. If the Al content is too low, this effect cannot be obtained. On the other hand, if the Al content is too high, coarse cluster-like alumina inclusion particles are formed during circumferential welding, and the toughness at the weld heat affected zone (HAZ) decreases. Therefore, the Al content is 0.005 to 0.100%.
  • the minimum with preferable Al content is higher than 0.005%, More preferably, it is 0.010%, More preferably, it is 0.020%.
  • the upper limit with preferable Al content is less than 0.100%, More preferably, it is 0.060%, More preferably, it is 0.040%.
  • Al content means content of acid-soluble Al (sol.Al).
  • Ca 0.0003 to 0.0050%
  • Calcium (Ca) suppresses clogging of the tundish nozzle during casting. Further, Ca suppresses the generation of HIC, blisters, and MnS that are the starting points of fine internal cracks. Therefore, Ca suppresses the generation of blisters and fine internal cracks. If the Ca content is too low, this effect will be insufficient. On the other hand, if the Ca content is too high, inclusions form clusters, and the toughness and HIC resistance of the steel decrease. Therefore, the Ca content is 0.0003 to 0.0050%.
  • the minimum with preferable Ca content is higher than 0.0003%, More preferably, it is 0.0010%, More preferably, it is 0.0015%.
  • the upper limit with preferable Ca content is less than 0.0050%, More preferably, it is 0.0040%, More preferably, it is 0.0030%.
  • N 0.0100% or less Nitrogen (N) is an impurity. N forms coarse nitrides and lowers the toughness and SSC resistance of the steel. Therefore, a lower N content is preferable. Therefore, the N content is 0.0100% or less. The preferable N content is 0.0080% or less, and more preferably 0.0060% or less.
  • Oxygen (O) is an impurity. O forms coarse oxides or oxide clusters to lower the toughness and HIC resistance of the steel. Therefore, it is preferable that the O content is as low as possible. Therefore, the O content is 0.0050% or less.
  • the O content is preferably 0.0040% or less, and more preferably 0.0030% or less.
  • the balance of the chemical composition of the seamless steel pipe of this embodiment is composed of Fe and impurities.
  • Impurities here refer to ores and scraps used as raw materials for steel, or elements mixed from the environment of the manufacturing process.
  • the seamless steel pipe of this embodiment may further contain one or more selected from the group consisting of Ti, V, Cr, Mo, Ni, Cu and B. All of these elements increase the strength of the steel.
  • Titanium (Ti) is a selective element. Ti, like Nb, combines with C and N to form carbonitrides and refines the steel by pinning hardening. On the other hand, if the Ti content is too high, the effect is saturated. Therefore, the Ti content is 0 to 0.1%.
  • the minimum with preferable Ti content is 0.002%, More preferably, it is 0.005%.
  • the upper limit with preferable Ti content is less than 0.1%, More preferably, it is 0.05%.
  • V 0 to 0.03%
  • Vanadium (V) is a selective element. V forms carbides and strengthens the steel. On the other hand, if the V content is too high, coarse carbides are formed and SSC tends to occur. Therefore, the V content is 0 to 0.03%.
  • the minimum with preferable V content is 0.01%, More preferably, it is 0.015%.
  • the upper limit with preferable V content is less than 0.03%, More preferably, it is 0.025%.
  • Cr 0 to 0.6% Mo: 0 to 0.3% Ni: 0 to 0.4%
  • Cu 0 to 0.3%
  • Chromium (Cr), molybdenum (Mo), nickel (Ni), and copper (Cu) are all selective elements. All of these elements enhance the hardenability of the steel and strengthen the steel, and increase the HIC resistance in low-strength steel. On the other hand, if the content of these elements is too high, a hardened structure is generated locally, or uneven corrosion of the steel surface may be caused. Therefore, the Cr content is 0 to 0.6%, the Mo content is 0 to 0.3%, the Ni content is 0 to 0.4%, and the Cu content is 0 to 0.3%. %.
  • the minimum with preferable Cr content is 0.01%, More preferably, it is 0.05%.
  • the minimum with preferable Mo content is 0.01%, More preferably, it is 0.05%.
  • the minimum with preferable Ni content is 0.01%, More preferably, it is 0.05%.
  • the minimum with preferable Cu content is 0.01%, More preferably, it is 0.05%.
  • the upper limit with preferable Cr content is less than 0.6%, More preferably, it is 0.5%.
  • the upper limit with preferable Mo content is less than 0.3%, More preferably, it is 0.25%.
  • the upper limit with preferable Ni content is less than 0.4%, More preferably, it is 0.3%, More preferably, it is 0.25%.
  • the upper limit with preferable Cu content is less than 0.3%, More preferably, it is 0.25%.
  • the total content of Cr, Mo, Ni, and Cu satisfies the following formula (2).
  • the content (mass%) of the corresponding element is substituted for each element symbol in the formula (2). If Cr, Mo, Ni, and Cu satisfy Expression (2), the yield strength is less than 450 MPa even for a thick-walled seamless steel pipe.
  • B 0 to 0.005%
  • Boron (B) is a selective element. B enhances the hardenability of steel in a low-strength seamless steel pipe, and enhances HIC resistance in a low-strength steel. On the other hand, if the B content is too high, the SSC resistance of the steel decreases. Therefore, the B content is 0 to 0.005%.
  • the minimum with preferable B content is 0.0001% or more, More preferably, it is 0.0003%.
  • the upper limit with preferable B content is less than 0.005%, More preferably, it is 0.003%.
  • the seamless steel pipe of this embodiment is not quenched and tempered after pipe making. That is, the seamless steel pipe of this embodiment is a so-called as-roll material in which quenching and tempering are omitted. As will be described later, the seamless steel pipe after pipe making is allowed to cool or cooled at a cooling rate of less than 2 ° C./s. Therefore, the structure of the seamless steel pipe of this embodiment is composed of ferrite and pearlite. Most of the structure is ferrite and the rest is pearlite. The structure here means a matrix structure that does not contain inclusions and precipitates.
  • the seamless steel pipe of this embodiment has a yield strength of 350 MPa or more.
  • the yield strength means 0.2% proof stress.
  • the preferred yield strength of the seamless steel pipe is 400 MPa or more. In the seamless steel pipe of this embodiment, the yield strength is less than 450 MPa.
  • ⁇ Steel with the above chemical composition is melted and refined by a well-known method. Subsequently, the molten steel is made into a continuous cast material by a continuous casting method.
  • the continuous cast material is, for example, a slab, bloom or billet. Moreover, you may make molten steel into an ingot by an ingot-making method.
  • S Billets are manufactured by hot working slabs, blooms and ingots of continuous cast materials.
  • billets are manufactured by rolling a slab, a bloom, or an ingot.
  • the manufactured billet is hot-made to produce a seamless steel pipe. Specifically, the billet is heated in a heating furnace. If hot pipe making is performed with coarse Nb inclusions remaining in the heated billet, Nb strengthening cannot be sufficiently obtained during cooling after hot pipe making. Therefore, in this embodiment, it heats even higher temperature compared with the time of manufacture of a normal seamless steel pipe. Specifically, the billet is heated to 1250 ° C. or higher during the heating.
  • Seamless steel pipes are manufactured by hot working the billet extracted from the heating furnace. Specifically, piercing and rolling based on the Mannesmann method is performed to manufacture a raw pipe. Further, the produced raw pipe is further subjected to stretching rolling and constant diameter rolling by a mandrel mill, a reducer, a sizing mill or the like to produce a seamless steel pipe.
  • the seamless steel pipe is cooled at a cooling rate of 0.5 to 5 ° C./s until the temperature of the seamless steel pipe reaches 500 ° C., and thereafter cooled at a cooling rate of less than 2 ° C.
  • the cooling rate of less than 2 ° C./s includes cooling.
  • the cooling rate can be adjusted, for example, by adjusting the interval between adjacent seamless steel pipes during cooling. For example, until the seamless steel pipe reaches 500 ° C., the distance between the adjacent seamless steel pipes is set as the distance D1, and at 500 ° C. or less, the distance is adjusted to the distance D2 shorter than the distance D1. Thereby, a gentle two-stage cooling rate can be realized.
  • the seamless steel pipe after hot working is not quenched and tempered.
  • a 25 ° C. test bath is prepared in which 5% NaCl + 0.5% CH 3 COOH aqueous solution is saturated with 100% H 2 S gas at atmospheric pressure.
  • the coupon specimen is immersed in the test bath for 96 hours. After immersing for 96 hours, the surface of the coupon test piece (20 mm width ⁇ 100 mm length corresponding to the inner and outer surfaces of the seamless steel pipe) is visually observed. Then, the total number of blisters generated on the surface is counted to obtain the number of blisters (pieces / 20 cm 2 ).
  • blistering can be suppressed by increasing the yield strength to 350 MPa or more with C and Nb. Therefore, it is excellent in HIC resistance, and SOHIC hardly occurs when a tensile stress is applied.
  • the chemical compositions of Steel A1 to Steel A15 were within the range of the chemical composition of the seamless steel pipe of this embodiment.
  • steel B1 and steel B3 did not contain Nb, and the Nb content of steel B2 was less than the lower limit of the Nb content of this embodiment.
  • the C content of steel B4 and steel B5 was less than the lower limit of the C content of the seamless steel pipe of this embodiment.
  • F2 of steel type B6 did not satisfy the formula (2).
  • Each steel ingot was hot forged to produce a plurality of billets for each steel.
  • the billet was heated at the heating temperature shown in Table 2, and then the billet was pierced and rolled using a piercing machine (piercer) to produce a seamless steel pipe.
  • piercer a piercing machine
  • the manufactured seamless steel pipe was cooled at the first cooling rate shown in Table 2 until the temperature of the seamless steel pipe reached 500 ° C., and thereafter cooled at the second cooling rate.
  • Microstructure observation test A microstructure observation test was carried out on three types of thick seamless steel pipes manufactured for each steel. In the cross section of each seamless steel pipe (surface perpendicular to the axial direction of the seamless steel pipe), the central thickness portion was etched with nital or the like. One arbitrary visual field (visual field area 40000 ⁇ m 2 ) of the etched thickness central portion was observed. A 500 ⁇ optical microscope was used for observation.
  • each seamless steel pipe had a structure composed of ferrite and pearlite.
  • yield strength test A round bar tensile test piece having a parallel portion with an outer diameter of 6 mm and a length of 40 mm was collected from each of the three types of seamless steel pipes of each steel. The parallel part was parallel to the axial direction of the seamless steel pipe. Using the collected round bar tensile test pieces, a tensile test was performed at room temperature (25 ° C.) to obtain a yield strength YS (0.2% proof stress) (MPa).
  • Table 2 shows the test results. Further, FIG. 2 is a photographic image of two surfaces (corresponding to the outer and inner surfaces of a seamless steel pipe) of a coupon test piece after a blister count measurement test of steel A4 (thickness 20 mm), and FIG. It is a photograph image of two surfaces of a coupon test piece after a blister number measurement test of a wall thickness of 20 mm). 2 and 3, the upper surface corresponds to the outer surface of the seamless steel pipe, and the lower surface corresponds to the inner surface of the seamless steel pipe.
  • the chemical compositions of steels A1 to A11, A14 and A15 were appropriate. Therefore, in a 12.7 mm seamless steel pipe having a wall thickness of 15 mm or less, the yield strength YS was 350 to less than 450 MPa. Therefore, as shown in FIG. 2, the generation of blisters on the surface was suppressed, and the number of blisters was less than 10/20 cm 2 .
  • the Nb contents of the steels A1 to A9 and A11, A14 and A15 were not less than the F1 value defined by the formula (1) in the seamless steel pipe having a thickness of 25.4 mm. Therefore, even in a seamless steel pipe having a wall thickness exceeding 15 mm, a yield strength of 350 to less than 450 MPa was obtained, and the number of blisters was less than 10 pieces / 20 cm 2 .
  • the Nb contents of the steels A2 to A9, A14 and A15 were F1 values or more in the seamless steel pipe having a wall thickness of 38.1 mm. Therefore, even in a seamless steel pipe having a wall thickness exceeding 35 mm, a yield strength of 350 to less than 450 MPa was obtained, and the number of blisters was less than 10 pieces / 20 cm 2 .
  • the heating temperature was too low for steel A12, and the first cooling rate was too slow for steel A13. Therefore, the yield strength YS was less than 350 MPa, and the number of blisters was 10/20 cm 2 or more in any thickness seamless steel pipe.
  • the Nb content of steels B1 to B3 was too low. Therefore, even in a seamless steel pipe having a wall thickness of less than 20 mm, the yield strength was less than 350 MPa. As a result, as shown in FIG. 3, a large number of blisters were generated on the surface, and the number of blisters was 10/20 cm 2 or more.
  • C content of steel B4 and B5 was too low. Therefore, even in a seamless steel pipe having a wall thickness of less than 20 mm, the yield strength was less than 350 MPa, and the number of blisters was 10/20 cm 2 or more.
  • the F2 value of steel B6 did not satisfy the formula (2). Therefore, the yield strength of steel B6 exceeded 450 MPa.

Landscapes

  • 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)
  • Manufacturing & Machinery (AREA)
  • Heat Treatment Of Articles (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

La présente invention concerne un tube en acier sans soudure qui est destiné à être utilisé dans un tube de canalisation utilisé dans un environnement acide, qui ne nécessite pas de durcissement ou de trempage, et qui permet de minimiser l'apparition de cloques. Un tube en acier sans soudure selon un mode de réalisation de la présente invention est caractérisé par : une composition chimique qui comprend, en % en poids, 0,08 à 0,24 % de C, 0,10 à 0,50 % de Si, 0,3 à 2,5 % de Mn, 0,02 % ou moins de P, 0,006 % ou moins de S, 0,02 à 0,12 % de Nb, 0,005 à 0,100 % d'Al, 0,0003 à 0,0050 % de Ca, 0,0100 % ou moins de N, 0,0050 % ou moins d'O, 0 à 0,1 % de Ti, 0 à 0,03 % de V, 0 à 0,6 % de Cr, 0 à 0,3 % de Mo, 0 à 0,4 % de Ni, 0 à 0,3 % de Cu, 0 à 0,005 % de B, le reste étant du Fe et des impuretés inévitables ; et une structure qui comprend de la ferrite et de la pyrite. Le tube en acier sans soudure présente une limite d'élasticité égale ou supérieure à 350 et inférieure à 450 MPa.
PCT/JP2014/002662 2013-05-31 2014-05-21 Tube en acier sans soudure destiné à un tube de canalisation utilisé dans un environnement acide WO2014192251A1 (fr)

Priority Applications (5)

Application Number Priority Date Filing Date Title
CN201480031110.2A CN105283572B (zh) 2013-05-31 2014-05-21 酸环境下使用的管线管用无缝钢管
MX2015016413A MX2015016413A (es) 2013-05-31 2014-05-21 Tubo sin soldadura para una linea de tuberia utilizada en ambientes acidos.
EP14803329.3A EP3006585B8 (fr) 2013-05-31 2014-05-21 Tube en acier sans soudure destiné à un tube de canalisation utilisé dans un environnement acide
JP2015519628A JP5915818B2 (ja) 2013-05-31 2014-05-21 サワー環境で使用されるラインパイプ用継目無鋼管
SA515370210A SA515370210B1 (ar) 2013-05-31 2015-11-29 أنبوب فولاذي غير ملحوم لخط الأنابيب المستخدم في الأوساط الحامضية

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2013-115135 2013-05-31
JP2013115135 2013-05-31

Publications (1)

Publication Number Publication Date
WO2014192251A1 true WO2014192251A1 (fr) 2014-12-04

Family

ID=51988303

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/002662 WO2014192251A1 (fr) 2013-05-31 2014-05-21 Tube en acier sans soudure destiné à un tube de canalisation utilisé dans un environnement acide

Country Status (7)

Country Link
EP (1) EP3006585B8 (fr)
JP (1) JP5915818B2 (fr)
CN (1) CN105283572B (fr)
AR (1) AR096272A1 (fr)
MX (1) MX2015016413A (fr)
SA (1) SA515370210B1 (fr)
WO (1) WO2014192251A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018534417A (ja) * 2015-09-24 2018-11-22 バオシャン アイアン アンド スティール カンパニー リミテッド 効果的に結晶粒を微細化する継目無鋼管のオンライン制御冷却方法および製造方法
CN114438406A (zh) * 2021-12-27 2022-05-06 天津钢管制造有限公司 酸性环境用机械复合管无缝母管

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106011626B (zh) * 2016-07-04 2017-10-17 湖南华菱湘潭钢铁有限公司 一种临氢中厚钢板的生产方法
CN106191671B (zh) * 2016-07-12 2017-11-14 达力普石油专用管有限公司 高强度抗硫化氢腐蚀无缝管线管及其制备方法
CN108359893B (zh) * 2018-02-23 2020-06-23 鞍钢股份有限公司 一种高硅低锰管线钢热轧卷板及其生产方法
ES2906376T3 (es) * 2018-09-20 2022-04-18 Vallourec Tubes France Tubo sin costura de acero microaleado de alta resistencia para servicio en entornos ácidos y aplicaciones de alta tenacidad
WO2022120337A1 (fr) * 2020-12-04 2022-06-09 ExxonMobil Technology and Engineering Company Acier de tube de canalisation à compositions d'acier ordinaire différentes pour une résistance améliorée à la fissuration sous contrainte induite par sulfure

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59150066A (ja) * 1983-02-14 1984-08-28 Sumitomo Metal Ind Ltd 高靭性継目無鋼管
JPS63250418A (ja) * 1987-04-07 1988-10-18 Nippon Steel Corp 高強度低降伏比ラインパイプの製造方法
JPH01234521A (ja) * 1988-03-14 1989-09-19 Nippon Steel Corp 耐硫化物応力腐食割れ性の優れた高靭性低降伏比鋼材の製造法
JP2002060893A (ja) 2000-08-18 2002-02-28 Sumitomo Metal Ind Ltd 耐硫化物応力腐食割れ性に優れた油井用鋼とその製造方法
WO2005075694A1 (fr) 2004-02-04 2005-08-18 Sumitomo Metal Industries,Ltd. Produit d’acier pour tuyau d’oleoduc d’excellente resistance hic et tuyau d’oleoduc fabrique a l’aide du produit d’acier
WO2011152240A1 (fr) 2010-06-02 2011-12-08 住友金属工業株式会社 Tube en acier sans soudure pour une canalisation et son procédé de production
JP2012509398A (ja) * 2008-11-20 2012-04-19 フェストアルピーネ チューブラーズ ゲゼルシャフト ミット ベシュレンクテル ハフツング ウント コンパニー コマンディートゲゼルシャフト 特殊な特性を有する鋼管を製造する方法及び装置

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5831031A (ja) * 1981-08-17 1983-02-23 Nippon Steel Corp 強度と靭性のすぐれた鋼管の製造法
JP2578598B2 (ja) * 1987-04-08 1997-02-05 新日本製鐵株式会社 耐硫化物応力腐食割れ性の優れた低降伏比鋼材の製造法
WO1996036742A1 (fr) * 1995-05-15 1996-11-21 Sumitomo Metal Industries, Ltd. Procede de production de tubes d'acier sans soudure a haute resistance, non susceptibles de fissuration par les composes soufres
JP3965708B2 (ja) * 1996-04-19 2007-08-29 住友金属工業株式会社 靱性に優れた高強度継目無鋼管の製造方法
JPH10237583A (ja) * 1997-02-27 1998-09-08 Sumitomo Metal Ind Ltd 高張力鋼およびその製造方法
JP2003119543A (ja) * 2001-10-15 2003-04-23 Nippon Steel Corp 塑性歪による靭性劣化の少ない溶接構造用鋼材およびその製造方法
CN101285153B (zh) * 2008-05-09 2010-06-09 攀钢集团成都钢铁有限责任公司 一种耐火钢、耐火无缝钢管及其生产方法
WO2011052095A1 (fr) * 2009-10-28 2011-05-05 新日本製鐵株式会社 Tôle d'acier pour des tubes de canalisation présentant une excellente résistance et une excellente ductilité et procédé de fabrication de cette dernière
CN102392185B (zh) * 2011-10-28 2013-05-22 首钢总公司 一种正火态抗酸性热轧钢板及其制备方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS59150066A (ja) * 1983-02-14 1984-08-28 Sumitomo Metal Ind Ltd 高靭性継目無鋼管
JPS63250418A (ja) * 1987-04-07 1988-10-18 Nippon Steel Corp 高強度低降伏比ラインパイプの製造方法
JPH01234521A (ja) * 1988-03-14 1989-09-19 Nippon Steel Corp 耐硫化物応力腐食割れ性の優れた高靭性低降伏比鋼材の製造法
JP2002060893A (ja) 2000-08-18 2002-02-28 Sumitomo Metal Ind Ltd 耐硫化物応力腐食割れ性に優れた油井用鋼とその製造方法
WO2005075694A1 (fr) 2004-02-04 2005-08-18 Sumitomo Metal Industries,Ltd. Produit d’acier pour tuyau d’oleoduc d’excellente resistance hic et tuyau d’oleoduc fabrique a l’aide du produit d’acier
JP2012509398A (ja) * 2008-11-20 2012-04-19 フェストアルピーネ チューブラーズ ゲゼルシャフト ミット ベシュレンクテル ハフツング ウント コンパニー コマンディートゲゼルシャフト 特殊な特性を有する鋼管を製造する方法及び装置
WO2011152240A1 (fr) 2010-06-02 2011-12-08 住友金属工業株式会社 Tube en acier sans soudure pour une canalisation et son procédé de production

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of EP3006585A4 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2018534417A (ja) * 2015-09-24 2018-11-22 バオシャン アイアン アンド スティール カンパニー リミテッド 効果的に結晶粒を微細化する継目無鋼管のオンライン制御冷却方法および製造方法
CN114438406A (zh) * 2021-12-27 2022-05-06 天津钢管制造有限公司 酸性环境用机械复合管无缝母管

Also Published As

Publication number Publication date
MX2015016413A (es) 2016-03-03
EP3006585A4 (fr) 2017-03-01
EP3006585A1 (fr) 2016-04-13
AR096272A1 (es) 2015-12-16
CN105283572A (zh) 2016-01-27
JP5915818B2 (ja) 2016-05-11
SA515370210B1 (ar) 2018-08-26
JPWO2014192251A1 (ja) 2017-02-23
EP3006585B1 (fr) 2019-05-01
EP3006585B8 (fr) 2019-08-21
CN105283572B (zh) 2017-12-15

Similar Documents

Publication Publication Date Title
JP6677310B2 (ja) 鋼材及び油井用鋼管
EP3042976B1 (fr) Tôle d'acier pour tube de canalisation à paroi épaisse et à haute résistance mécanique ayant d'excellentes caracteristiques de résistance à la corrosion et à l'affaissement, et une ductilité aux basses températures, ainsi que tube de canalisation
JP5915818B2 (ja) サワー環境で使用されるラインパイプ用継目無鋼管
US9841124B2 (en) High-strength thick-walled electric resistance welded steel pipe having excellent low-temperature toughness and method of manufacturing the same
JP4475440B1 (ja) 継目無鋼管およびその製造方法
JP5880787B2 (ja) 低合金油井用鋼管及びその製造方法
JP6048626B1 (ja) 厚肉高靭性高強度鋼板およびその製造方法
JPWO2013133076A1 (ja) 耐硫化物応力割れ性に優れた高強度鋼材の製造方法
US10081042B2 (en) Electric resistance welded steel pipe excellent in weld zone and method of production of same
CN108699644B (zh) 无缝钢管及其制造方法
WO2016035316A1 (fr) Tuyau en acier à paroi épaisse pour puits de pétrole et son procédé de fabrication
JP5408389B1 (ja) 継目無鋼管及びその製造方法
JP6028863B2 (ja) サワー環境で使用されるラインパイプ用継目無鋼管
US20190040480A1 (en) Seamless steel pipe and method for producing same
JP2017031493A (ja) ステンレス鋼管の製造方法
JP6805639B2 (ja) ステンレス鋼管の製造方法
CN107849658B (zh) 不锈钢管及其制造方法
JP2023022159A (ja) 耐水素誘起割れ（ｈｉｃ）性が強化されたｘ－６５グレードのａｐｉ ５ｌ ｐｓｌ－２仕様に適合する鋼組成物及びその鋼の製造方法
WO2013114519A1 (fr) Tuyau en acier uoe pour tube de canalisation
EP3330398B1 (fr) Tuyau en acier pour un tuyau de canalisation et procédé permettant de produire ce dernier
JP5246280B2 (ja) 高強度鋼管用鋼板及び高強度鋼管
JP2013129870A (ja) 高強度ラインパイプ用継目無鋼管の製造方法
JP6152929B1 (ja) 油井用低合金高強度継目無鋼管
JP7226595B2 (ja) ラインパイプ用電縫鋼管
JP2017008362A (ja) ラインパイプ用継目無鋼管及びその製造方法

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201480031110.2

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14803329

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 2015519628

Country of ref document: JP

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: MX/A/2015/016413

Country of ref document: MX

NENP Non-entry into the national phase

Ref country code: DE

WWE Wipo information: entry into national phase

Ref document number: 2014803329

Country of ref document: EP