WO2018020972A1 - 高強度継目無鋼管及びライザー - Google Patents
高強度継目無鋼管及びライザー Download PDFInfo
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- C22C38/00—Ferrous alloys, e.g. steel alloys
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
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- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- 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
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- 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
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- 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
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
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- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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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
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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
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
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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
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
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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
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
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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
- C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with titanium or zirconium
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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
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
Definitions
- the present invention relates to a high-strength seamless steel pipe and a riser using the same, and more particularly to a high-strength seamless steel pipe suitable for a work over riser and a riser using the same.
- a flow line is a steel pipe for transportation laid along the terrain on the ground or at the bottom of the sea.
- a riser is a steel pipe for transportation that rises from the sea floor to an offshore platform.
- Flow lines and risers laid in the deep sea receive pressure from a high-pressure fluid with deep formation pressure.
- seawater pressure in the deep sea When operations are stopped, it is affected by seawater pressure in the deep sea.
- the riser is further affected by repeated distortion caused by waves. Therefore, high strength is required for the flow line and the riser, and a thick steel pipe having a thickness of 30 mm or more is used.
- Workover riser is used for trial operation and test production of well equipment in offshore oil field development.
- the work over riser can come into contact with the production fluid during test production. Therefore, the work over riser may be required to have sour resistance in addition to high strength.
- Japanese Patent No. 4502010 discloses a seamless steel pipe for a line pipe that can ensure high strength, stable toughness and good corrosion resistance with a seamless steel pipe having a large thickness, and a method for manufacturing the same.
- this publication describes a steel pipe for a line pipe having a wall thickness of 40 mm, a yield strength of 555 MPa or more, and excellent resistance to sulfide stress corrosion cracking (SSC resistance).
- Japanese Unexamined Patent Application Publication No. 2013-32584 discloses a thick high-strength seamless steel pipe excellent in sour resistance and a manufacturing method thereof.
- this publication describes a seamless steel pipe having a wall thickness of 30 mm, a yield strength of 600 MPa, and excellent sour resistance.
- Japanese Patent No. 5516831 has high strength and excellent hydrogen-induced cracking resistance (HIC resistance), and even in the case of circumferential welding, the HIC resistance of the heat affected zone (HAZ) is improved.
- HIC resistance hydrogen-induced cracking resistance
- HZ heat affected zone
- An excellent seamless steel pipe suitable for a line pipe is disclosed.
- this publication describes a seamless steel pipe having a wall thickness of 40 mm, a yield strength of 555 MPa or more, and excellent HIC resistance.
- ISO 15156 stipulates that the hardness of the surface layer of a carbon steel line pipe that requires SSC resistance is controlled to 250 Hv or less.
- the steel pipe for line pipe has low hardenability as described above, the hardness at the center of the thickness with a small cooling rate is difficult to increase during quenching, and the hardness of the surface layer with a high cooling rate is relatively high. This hardness distribution is inherited even after tempering. As a result, it is difficult to manage the hardness of the surface layer low, particularly in thick steel pipes.
- Japanese Patent Application Laid-Open No. 2013-32584 describes a method of grinding a high hardness portion of a surface layer after quenching, a method of decarburizing a surface before quenching, a method of quenching in a film boiling state, and the like.
- these methods are greatly different from the manufacturing process of a general seamless steel pipe, there is a concern about a decrease in manufacturing efficiency.
- Japanese Patent No. 4502010 and Japanese Patent No. 5516831 do not mention a specific method for hardness management.
- An object of the present invention is to provide a high-strength seamless steel pipe and a riser capable of ensuring both high strength and low hardness while ensuring weldability.
- the high-strength seamless steel pipe has a chemical composition of mass%, C: 0.10 to 0.18%, Si: 0.03 to 1.0%, Mn: 0.5 to 2.0%, P: 0.020% or less, S: 0.0080% or less, Cr: 0.10 to 0.60%, Mo: 0.10 to 0.40%, V: 0.02 to 0 40%, Ti: 0.004-0.020%, B: 0.0005-0.005%, Al: 0.10% or less, N: 0.008% or less, Ca: 0.0004-0. 0040%, Cu: 0.1 to 1.0%, Ni: 0.2 to 1.0%, Nb: 0 to 0.05%, balance: Fe and impurities, satisfying the following formula (1) .
- the content of the corresponding element is substituted by mass%.
- FIG. 1 is a diagram schematically showing a measurement position of HAZ hardness.
- FIG. 2 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 1.
- FIG. 3 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 2.
- FIG. 4 is a view showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 3.
- FIG. 5 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 4.
- FIG. 6 is a view showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 5.
- FIG. 7 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 6.
- FIG. 8 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 7.
- FIG. 9 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 8.
- FIG. 10 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 9.
- FIG. 11 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 10.
- the present inventors examined a high-strength seamless steel pipe capable of achieving both high strength and low hardness while ensuring weldability. As a result, the following knowledge was obtained.
- Boron (B) is considered not to be an element that is positively contained in the steel for line pipes because it significantly deteriorates the weldability.
- the hardenability of steel can be remarkably improved by containing an appropriate amount of B within a range that satisfies PCM ⁇ 0.28.
- it is effective to contain a predetermined amount of Cu and Ni that are elements that improve hardenability and have a relatively small effect on PCM. As a result, a hardened structure can be obtained up to the center of the thickness even with a thick steel pipe, and both high strength and low hardness can be achieved.
- the hardness variation in the cross section perpendicular to the pipe axis direction can be reduced. This also contributes to an improvement in the toughness of the steel pipe. Excellent toughness can be obtained by suppressing hardness variation and appropriately limiting impurities such as P and S.
- the high-strength seamless steel pipe according to this embodiment has a chemical composition described below.
- “%” of the element content means mass%.
- C 0.10 to 0.18% Carbon (C) increases the hardenability of the steel. If the C content is less than 0.10%, the above effects cannot be obtained sufficiently. On the other hand, if the C content exceeds 0.18%, the weldability of the steel decreases. Therefore, the C content is 0.10 to 0.18%.
- the lower limit of the C content is preferably 0.12%.
- the upper limit of the C content is preferably 0.15%.
- Si 0.03-1.0% Silicon (Si) deoxidizes steel. If the Si content is 0.03% or more, the above effect is remarkably obtained. However, if the Si content exceeds 1.0%, the toughness of the steel decreases. Therefore, the Si content is 0.03 to 1.0%.
- the lower limit of the Si content is preferably 0.05%, more preferably 0.10%.
- the upper limit of the Si content is preferably 0.8%, and more preferably 0.5%.
- Mn 0.5 to 2.0%
- Manganese (Mn) increases the hardenability of the steel. If the Mn content is less than 0.5%, the above effect cannot be obtained sufficiently. On the other hand, if the Mn content exceeds 2.0%, Mn is segregated in the steel and the toughness of the steel is lowered. Therefore, the Mn content is 0.5 to 2.0%.
- the lower limit of the Mn content is preferably 0.6%.
- the upper limit of the Mn content is preferably 1.5%, more preferably 1.0%.
- Phosphorus (P) is an impurity. P decreases the toughness of the steel. Therefore, the P content is preferably as low as possible. Therefore, the P content is 0.020% or less. The P content is preferably 0.015% or less, more preferably 0.013% or less.
- S 0.0080% or less Sulfur (S) is an impurity. S combines with Mn to form coarse MnS and lowers the toughness and HIC resistance of the steel. Accordingly, the S content is preferably as low as possible. Therefore, the S content is 0.0080% or less.
- the S content is preferably 0.0060% or less, and more preferably 0.0040% or less.
- Chromium (Cr) increases the hardenability of the steel. Cr further increases the temper softening resistance of the steel. If the Cr content is less than 0.10%, the above effect cannot be obtained sufficiently. On the other hand, when the Cr content exceeds 0.60%, weldability and HAZ toughness are lowered. Therefore, the Cr content is 0.10 to 0.60%.
- the lower limit of the Cr content is preferably 0.20%, more preferably 0.25%, and further preferably 0.30%.
- the upper limit of the Cr content is preferably 0.55%, more preferably 0.50%.
- Mo 0.10 to 0.40% Molybdenum (Mo) increases the hardenability of the steel. Mo further combines with C and V in the steel to increase the strength of the steel. If the Mo content is less than 0.10%, the above effects cannot be obtained sufficiently. On the other hand, if the Mo content exceeds 0.40%, the weldability and the HAZ toughness of the steel decrease. Therefore, the Mo content is 0.10 to 0.40%.
- the lower limit of the Mo content is preferably 0.20%, and more preferably 0.25%.
- the upper limit of the Mo content is preferably 0.35%.
- V 0.02 to 0.40% Vanadium (V) combines with C in the steel to form a V carbide and increases the strength of the steel. If the V content is less than 0.02%, the above effects cannot be obtained sufficiently. On the other hand, if the V content is higher than 0.40%, the carbides become coarse and the toughness of the steel decreases. Therefore, the V content is 0.02 to 0.40%.
- the lower limit of the V content is preferably 0.03%.
- the upper limit of the V content is preferably 0.30%, more preferably 0.20%, and even more preferably 0.10%.
- Ti 0.004 to 0.020% Titanium (Ti) combines with N in the steel to form TiN, and suppresses a decrease in the toughness of the steel due to the solid solution N. Furthermore, finely dispersed TiN increases the toughness of the steel. When the Ti content is less than 0.004%, the above effects cannot be obtained sufficiently. On the other hand, if the Ti content is higher than 0.020%, TiN coarsens or coarse TiC is generated, so that the toughness of the steel decreases. Therefore, the Ti content is 0.004 to 0.020%. The lower limit of the Ti content is preferably 0.010%.
- B 0.0005 to 0.005% Boron (B) drastically improves hardenability when contained in a small amount. This makes it possible to obtain a quenched structure up to the center of the wall thickness even for a thick steel pipe, and to achieve both high strength and low hardness. Moreover, by containing B, the range of the tempering conditions which can satisfy
- the B content is 0.0005 to 0.005%.
- the lower limit of the B content is preferably 0.0008%, and more preferably 0.0010%.
- the upper limit of the B content is preferably 0.0030%, more preferably 0.0020%, and further preferably 0.0015%.
- Al 0.10% or less
- Aluminum (Al) combines with N to form fine nitrides and enhances the toughness of the steel. If Al is contained even a little, the above effect can be obtained. On the other hand, if the Al content is higher than 0.10%, the Al nitride becomes coarse and the toughness of the steel decreases. Therefore, the Al content is 0.10% or less.
- the lower limit of the Al content is preferably 0.001%, and more preferably 0.01%.
- the upper limit of the Al content is preferably 0.08%, more preferably 0.06%.
- the Al content in this specification means the content of acid-soluble Al (so-called Sol-Al).
- N 0.008% or less Nitrogen (N) combines with Al to form fine Al nitride and enhances the toughness of the steel. If N is contained even a little, the above effect can be obtained. On the other hand, if the N content is higher than 0.008%, the solid solution N reduces the toughness of the steel. If the N content is too high, the carbonitrides are further coarsened and the toughness of the steel is reduced. Therefore, the N content is 0.008% or less.
- the lower limit of the N content is preferably 0.001%.
- the upper limit of the N content is preferably 0.006%, and more preferably 0.005%.
- Ca 0.0004 to 0.0040%
- Calcium (Ca) combines with S in steel to form CaS.
- the formation of MnS is suppressed by the formation of CaS. Therefore, Ca improves the toughness and HIC resistance of steel. It also has the function of suppressing toughening of alumina inclusions and improving toughness and HIC resistance.
- the Ca content is less than 0.0004%, the above effect cannot be obtained sufficiently.
- the Ca content is higher than 0.0040%, the cleanliness of the steel decreases, and the toughness and HIC resistance of the steel decrease. Therefore, the Ca content is 0.0004 to 0.0040%.
- the lower limit of the Ca content is preferably 0.0005%, more preferably 0.0008%.
- the upper limit of the Ca content is preferably 0.0035%, more preferably 0.0030%.
- Cu 0.1 to 1.0% Copper (Cu) increases the hardenability of the steel and increases the strength of the steel. If the Cu content is less than 0.1%, this effect cannot be sufficiently obtained. On the other hand, if the Cu content is higher than 1.0%, the weldability of steel decreases. If the Cu content is too high, the grain boundary strength of the steel at a high temperature is further lowered, and the hot workability of the steel is lowered. Therefore, the Cu content is 0.1 to 1.0%.
- the lower limit of the Cu content is preferably 0.12%, more preferably 0.15%.
- the upper limit of the Cu content is preferably 0.5%, more preferably 0.3%, and further preferably 0.2%.
- Ni 0.2 to 1.0%
- Nickel (Ni) increases the hardenability of the steel and increases the strength of the steel.
- Ni is also an element that enhances hardenability, but has little adverse effect on weldability.
- Ni further improves the toughness of the steel. If Ni is less than 0.2%, these effects cannot be obtained sufficiently.
- the Ni content is higher than 1.0%, the SSC resistance decreases. Therefore, the Ni content is 0.2 to 1.0%.
- the lower limit of the Ni content is preferably 0.3%, more preferably 0.35%, and further preferably 0.4%.
- the upper limit of the Ni content is preferably 0.9%, more preferably 0.8%.
- the balance of the chemical composition of the high-strength seamless steel pipe according to this embodiment is Fe and impurities.
- the impurity here refers to an element mixed from ore and scrap used as a raw material of steel, or an element mixed from the environment of the manufacturing process.
- the chemical composition of the high-strength seamless steel pipe according to this embodiment may contain Nb instead of a part of Fe.
- Nb is a selective element. That is, the chemical composition of the high-strength seamless steel pipe according to the present embodiment may not contain Nb.
- Niobium (Nb) combines with C and / or N in the steel to form fine Nb carbide, and increases the strength and toughness of the steel. Nb further dissolves in Mo carbide and suppresses coarsening of Mo carbide. If Nb is contained even a little, the above effect can be obtained. On the other hand, if the Nb content is higher than 0.05%, the carbides become coarse and the toughness of the steel decreases. Therefore, the Nb content is 0 to 0.05%.
- the lower limit of the Nb content is preferably 0.005%.
- the upper limit of the Nb content is preferably 0.04%, more preferably 0.03%.
- the chemical composition of the high-strength seamless steel pipe for the riser satisfies the following formula (1).
- the content of the corresponding element is substituted by mass%.
- PCM The value on the left side of Equation (1) is called PCM.
- the PCM is set to 0.28 or less.
- PCM is preferably 0.27 or less, more preferably 0.26 or less.
- the chemical composition of the high-strength seamless steel pipe for riser preferably has a carbon equivalent Ceq defined by the following formula (2) of 0.40 or more.
- Ceq C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15 Formula (2)
- the content of the corresponding element is substituted by mass%.
- Carbon equivalent Ceq is used as an index of hardenability. If the carbon equivalent Ceq is too small, sufficient hardenability cannot be obtained, and particularly in a thick steel pipe, the difference between the hardness of the surface layer and the hardness in the meat becomes large. Therefore, it becomes difficult to achieve both high strength and low hardness.
- the lower limit of the carbon equivalent Ceq is preferably 0.42, and more preferably 0.45. On the other hand, if the carbon equivalent Ceq is too large, it becomes difficult to ensure weldability.
- the upper limit of the carbon equivalent Ceq is preferably 0.55, and more preferably 0.50.
- the high-strength seamless steel pipe according to the present embodiment preferably has a yield strength of 555 MPa or more and a tensile strength of 625 MPa or more.
- the high-strength seamless steel pipe according to this embodiment more preferably has a yield strength of 600 MPa or more and a tensile strength of 670 MPa or more.
- the high-strength seamless steel pipe according to the present embodiment preferably has a surface layer hardness of 250 Hv or less. More specifically, it is preferable that the hardness at a position of 1 mm from the inner surface of the steel pipe and the hardness at a position of 1 mm from the outer surface of the steel pipe are both 250 Hv or less. The hardness is measured according to JIS Z 2244. More preferably, the high-strength seamless steel pipe according to the present embodiment has a surface layer hardness of 240 Hv or less.
- the high-strength seamless steel pipe according to the present embodiment preferably has a hardness variation in a cross section perpendicular to the tube axis direction (hereinafter referred to as “hardness variation in the same cross section”) of 15 Hv or less.
- the difference between the larger hardness value measured at a position 1 mm from the inner surface and 1 mm from the outer surface of the steel pipe and the average value of the hardness at the center of the wall thickness is preferably 15 Hv or less.
- the average value of the hardness of the thickness center be an average value measured at four points at the thickness center position (1/2 thickness position).
- the high-strength seamless steel pipe according to the present embodiment more preferably has a hardness variation of 13 Hv or less in the same cross section.
- the high-strength seamless steel pipe according to this embodiment preferably has a wall thickness of 30 mm or more.
- the high-strength seamless steel pipe according to the present embodiment preferably has a thickness of 35 mm or more, and more preferably has a thickness of 40 mm or more.
- the high-strength seamless steel pipe according to this embodiment is suitable for a riser.
- the high-strength seamless steel pipe according to this embodiment is particularly suitable for a work over riser.
- billets are produced from the molten steel by a continuous casting method.
- a slab or bloom may be produced from molten steel, and the billet may be produced by hot working the slab or bloom.
- the billet is hot-worked to produce a blank tube. Specifically, piercing rolling, stretching rolling, and constant diameter rolling are performed to manufacture a raw pipe.
- Quenching is a heat treatment in which the base tube is rapidly cooled from the austenite region. Quenching may be so-called direct quenching in which a hot raw tube after hot working is rapidly cooled as it is from a temperature of 3 or more points of Ar. So-called in-line quenching in which the temperature is soaked at three or more points and then rapidly cooled may be used. Alternatively, so-called reheating and quenching may be used, in which the elementary tube once cooled is reheated to a temperature of Ac 3 point or higher and then rapidly cooled.
- Temper the quenched pipe. Tempering is usually carried out at a temperature of Ac 1 point or less. The tempering conditions are adjusted according to the yield strength and hardness. Tempering conditions can be managed using the following tempering parameter TP.
- TP (T + 273) ⁇ (20 + log (t))
- T is a tempering temperature expressed in ° C
- t is a tempering time expressed in time
- log (t) is a common logarithm of t.
- the high-strength seamless steel pipe preferably has a high yield strength and a low surface hardness.
- the tempering parameter TP is adjusted so that necessary characteristics can be obtained.
- the high-strength seamless steel pipe and the riser using the same according to the present embodiment can achieve both high strength and low hardness while ensuring weldability.
- Steel type 1, steel type 2, and steel type 10 are steels that satisfy the preferred conditions of this embodiment.
- Steel type 3 is a comparative example in which a carbon equivalent Ceq is about the same as steel type 1 from the chemical composition of a general steel product for line pipes with a low C content.
- Steel type 4 is a comparative example in which a carbon equivalent Ceq is about the same as that of steel type 1 from the chemical composition of a general steel product for line pipes containing Nb.
- Steel type 5 is a comparative example in which the C content and carbon equivalent Ceq are set to the same level as steel type 1 and the B content is lowered.
- Steel type 6 is a comparative example simulating a high carbon equivalent steel material used for oil well steel pipes and the like.
- Steel type 7 is a comparative example in which the Ca content is low.
- Steel type 8 is a comparative example in which the Cu and Ni contents are low.
- Steel type 9 is a comparative example in which the Mo content is low.
- the manufactured round billet was heated to 1100-1300 ° C. in a heating furnace and pierced and rolled by a piercing machine. Further, the steel pipe was drawn and rolled by a mandrel mill and fixed diameter rolled by a sizer to produce a seamless steel pipe having an outer diameter (OD) and a wall thickness (WT) shown in Table 2. Each seamless steel pipe was quenched and tempered under the conditions shown in Table 2 to produce Item A to L seamless steel pipes.
- test piece including the inner surface From each seamless steel pipe after tempering, a test piece including the inner surface, a test piece including the wall thickness center, and a test piece including the outer surface were collected. Each test piece had a thickness of 30 mm, a width (circumferential direction) of 20 mm, and a length of 100 mm. According to NACE TM0284-2003, the HIC resistance of each test piece was evaluated.
- the test bath was a room temperature 5% salt + 0.5% acetic acid aqueous solution saturated with 1 atm hydrogen sulfide gas. After 96 hours from the immersion, each test piece was cut into three equal parts in the longitudinal direction, and the presence or absence of cracks was visually confirmed. Furthermore, the presence or absence of a crack was confirmed with respect to the test piece including the inner surface of the steel pipe by ultrasonic flaw detection.
- Results are shown in the “HIC” column of Table 2. “No HIC” in the “HIC” column indicates that no crack was confirmed. “HIC” indicates that a crack was confirmed.
- test piece including the inner surface From each seamless steel pipe after tempering, a test piece including the inner surface, a test piece including the wall thickness center, and a test piece including the outer surface were collected. Each test piece had a thickness of 2 mm, a width (circumferential direction) of 20 mm, and a length of 100 mm. These test pieces were immersed in the same NACE test bath as the HIC test described above for 720 hours in a state where a stress of 90% of the yield strength was applied. The presence or absence of the crack of the test piece after immersion was investigated.
- a circumferential welded joint was prepared using each seamless steel pipe after tempering, and a HAZ hardness test was performed.
- the groove shape is 5 ° narrow groove
- the welding process is GMAW (gas metal arc welding)
- the welding conditions are heat input at welding 1.0 kJ / mm
- FIG. 1 is a diagram schematically showing the measurement position of the HAZ hardness.
- the circumferential weld joint was cut in parallel with the pipe axis direction.
- 7 points of hardness were measured at intervals of 1.0 mm from the position of 1.5 mm from the inner surface of the steel pipe toward the outer surface in the thickness direction.
- the highest hardness in the measurement point was the highest HAZ hardness.
- the results are shown in the column of “maximum HAZ hardness” in Table 2.
- Item A, Item B, and Item L manufactured from Steel Type 1, Steel Type 2, and Steel Type 10 that satisfy the preferred conditions of this embodiment have a yield strength of 555 MPa or more and a tensile strength of 625 MPa or more.
- the hardness of the surface layer was 250 Hv or less.
- the variation in hardness in the same cross section was 15 Hv or less.
- the maximum HAZ hardness was 250 Hv or less.
- the absorbed energy exceeded 100 J and the toughness was high.
- Item C manufactured from steel type 3 did not satisfy the requirements of the X80 grade in yield strength and tensile strength.
- Item D manufactured by changing the tempering conditions from the same steel type 3 satisfied the specification of the X80 grade, but the hardness of the surface layer exceeded 250 Hv. Therefore, Item D confirmed cracks in the SSC test.
- Item E produced from steel type 4 had a yield strength and a tensile strength satisfying the rules of the X80 grade, and the hardness of the surface layer was 250 Hv or less. However, the variation in hardness of the same cross section was greater than 15 Hv.
- the yield strength and tensile strength of Item E are close to the lower limit of the X80 grade, and the hardness of the surface layer is close to the upper limit specified in ISO 15156. Therefore, these regulations may not be met due to fluctuations in operating conditions.
- Item F manufactured by changing the tempering conditions from the same steel type 4 has a surface hardness exceeding 250 Hv. Therefore, in Item F, cracks were confirmed in the SSC test.
- Item G manufactured from steel type 5 did not satisfy the X80 grade.
- Item H produced from steel type 6 had a yield strength and a tensile strength satisfying the rules of the X80 grade, and the hardness of the surface layer was 250 Hv or less. However, the maximum HAZ hardness showed a high value exceeding 260 Hv. Further, the absorbed energy was less than 100 J in the Charpy impact test.
- Item I manufactured from steel type 7 had a yield strength and a tensile strength satisfying the rules of the X80 grade, and the height of the surface layer was 250 Hv or less. However, cracks occurred in the HIC test, and the absorbed energy was less than 100 J in the Charpy impact test.
- ItemJ manufactured from steel type 8 had a surface hardness exceeding 250 Hv. Therefore, ItemJ confirmed cracks in the SSC test.
- ItemK manufactured from steel type 9 did not satisfy the X80 grade of yield strength.
- the allowable TP width is defined as the minimum TP at which the hardness of the surface layer is 250 Hv or less as TP MIN , the maximum TP at which the yield strength is 555 MPa or more, and the maximum TP at which the tensile strength is 625 MPa or more.
- the allowable TP width is preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more.
- FIG. 2 is a diagram showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel type 1.
- FIGS. 3 to 11 are diagrams showing the relationship between the tempering parameter TP, the yield strength, the tensile strength, and the hardness of the surface layer in the steel types 2 to 10, respectively.
- Steel Type 1, Steel Type 2, and Steel Type 10 that satisfy the preferred conditions defined in this embodiment have a wider allowable TP width than Steel Types 3 to 9. It was. Therefore, even if the operating conditions fluctuate somewhat, it is possible to achieve both the strength of the X80 grade and the hardness of 250 Hv or less. Therefore, steel type 1, steel type 2, and steel type 10 can industrially stably produce a high-strength seamless steel pipe having the above performance.
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Abstract
Description
C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5×B≦0.28 式(1)
式(1)の元素記号には、質量%で、対応する元素の含有量が代入される。
PCM=C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5×B
上式の元素記号には、質量%で、対応する元素の含有量が代入される。
本実施形態による高強度継目無鋼管は、以下に説明する化学組成を有する。以下の説明において、元素の含有量の「%」は、質量%を意味する。
炭素(C)は、鋼の焼入れ性を高める。C含有量が0.10%未満であれば、上記効果が十分に得られない。一方、C含有量が0.18%を超えると、鋼の溶接性が低下する。したがって、C含有量は0.10~0.18%である。C含有量の下限は、好ましくは0.12%である。C含有量の上限は、好ましくは0.15%である。
シリコン(Si)は、鋼を脱酸する。Si含有量が0.03%以上であれば、上記効果が顕著に得られる。しかしながら、Si含有量が1.0%を超えると、鋼の靱性が低下する。したがって、Si含有量は0.03~1.0%である。Si含有量の下限は、好ましくは0.05%であり、さらに好ましくは0.10%である。Si含有量の上限は、好ましくは0.8%であり、さらに好ましくは0.5%である。
マンガン(Mn)は、鋼の焼入れ性を高める。Mn含有量が0.5%未満であれば、上記効果が十分に得られない。一方、Mn含有量が2.0%を超えると、Mnが鋼中で偏析し、鋼の靱性が低下する。したがって、Mn含有量は0.5~2.0%である。Mn含有量の下限は、好ましくは0.6%である。Mn含有量の上限は、好ましくは1.5%であり、さらに好ましくは1.0%である。
燐(P)は不純物である。Pは鋼の靱性を低下させる。したがって、P含有量はなるべく低い方が好ましい。そのため、P含有量は0.020%以下である。P含有量は、好ましくは0.015%以下であり、さらに好ましくは0.013%以下である。
硫黄(S)は不純物である。Sは、Mnと結合して粗大なMnSを形成し、鋼の靱性及び耐HIC性を低下させる。したがって、S含有量はなるべく低い方が好ましい。そのため、S含有量は0.0080%以下である。S含有量は、好ましくは0.0060%以下であり、さらに好ましくは、0.0040%以下である。
クロム(Cr)は鋼の焼入れ性を高める。Crはさらに、鋼の焼戻し軟化抵抗を高める。Cr含有量が0.10%未満では、上記効果が十分に得られない。一方、Cr含有量が0.60%を超えると、溶接性及びHAZ靱性が低下する。したがって、Cr含有量は0.10~0.60%である。Cr含有量の下限は、好ましくは0.20%であり、さらに好ましくは0.25%であり、さらに好ましくは0.30%である。Cr含有量の上限は、好ましくは0.55%であり、さらに好ましくは0.50%である。
モリブデン(Mo)は、鋼の焼入れ性を高める。Moはさらに、鋼中のC、Vと結合して鋼の強度を高める。Mo含有量が0.10%未満では、上記効果が十分に得られない。一方、Mo含有量が0.40%を超えると、鋼の溶接性及びHAZ靱性が低下する。したがって、Mo含有量は0.10~0.40%である。Mo含有量の下限は、好ましくは0.20%であり、さらに好ましくは0.25%である。Mo含有量の上限は、好ましくは0.35%である。
バナジウム(V)は、鋼中のCと結合してV炭化物を形成し、鋼の強度を高める。V含有量が0.02%未満では、上記効果が十分に得られない。一方、V含有量が0.40%よりも高ければ、炭化物が粗大化し、鋼の靱性が低下する。したがって、V含有量は0.02~0.40%である。V含有量の下限は、好ましくは0.03%である。V含有量の上限は、好ましくは0.30%であり、さらに好ましくは0.20%であり、さらに好ましくは0.10%である。
チタン(Ti)は、鋼中のNと結合してTiNを形成し、固溶したNによる鋼の靱性の低下を抑制する。さらに、分散析出した微細なTiNは鋼の靱性を高める。Ti含有量が0.004%未満では、上記効果が十分に得られない。一方、Ti含有量が0.020%よりも高ければ、TiNが粗大化したり、粗大なTiCが発生したりすることで、鋼の靱性が低下する。したがって、Ti含有量は0.004~0.020%である。Ti含有量の下限は、好ましくは0.010%である。
ボロン(B)は、微量の含有で焼入れ性を飛躍的に向上させる。これによって厚肉の鋼管であっても、肉厚中央まで焼入れ組織が得られ、高強度と低硬度との両立が可能になる。また、Bを含有することによって、所定の範囲の強度と硬度とを同時に満たすことができる焼戻し条件の範囲を広くすることができる。これによって、所定の範囲の強度と硬度とを同時に満たす継目無鋼管を工業的に安定的に生産することができる。B含有量が0.0005%未満では、上記効果が十分に得られない。一方、Bを過度に含有すると溶接性が急激に低下する。したがって、B含有量は0.0005~0.005%である。B含有量の下限は、好ましくは0.0008%であり、さらに好ましくは0.0010%である。B含有量の上限は、好ましくは0.0030%であり、さらに好ましくは0.0020%であり、さらに好ましくは0.0015%である。
アルミニウム(Al)は、Nと結合して微細な窒化物を形成し、鋼の靱性を高める。Alが少しでも含有されていれば、上記の効果が得られる。一方、Al含有量が0.10%よりも高ければ、Al窒化物が粗大化し、鋼の靱性が低下する。したがって、Al含有量は0.10%以下である。Al含有量の下限は、好ましくは0.001%であり、さらに好ましくは0.01%である。Al含有量の上限は、好ましくは0.08%であり、さらに好ましくは0.06%である。本明細書におけるAl含有量は、酸可溶Al(いわゆるSol-Al)の含有量を意味する。
窒素(N)は、Alと結合して微細なAl窒化物を形成し、鋼の靱性を高める。Nが少しでも含有されていれば、上記の効果が得られる。一方、N含有量が0.008%よりも高ければ、固溶したNが鋼の靱性を低下させる。N含有量が高すぎればさらに、炭窒化物が粗大化し、鋼の靱性が低下する。したがって、N含有量は0.008%以下である。N含有量の下限は、好ましくは0.001%である。N含有量の上限は、好ましくは0.006%であり、さらに好ましくは0.005%である。
カルシウム(Ca)は、鋼中のSと結合してCaSを形成する。CaSの形成により、MnSの形成が抑制される。そのため、Caは、鋼の靱性及び耐HIC性を高める。またアルミナ系介在物の粗大化も抑制し靱性及び耐HIC性を改善する働きもある。Ca含有量が0.0004%未満では、上記効果が十分に得られない。一方、Ca含有量が0.0040%よりも高ければ、鋼の清浄度が低下し、鋼の靱性及び耐HIC性が低下する。したがって、Ca含有量は0.0004~0.0040%である。Ca含有量の下限は、好ましくは0.0005%であり、さらに好ましくは0.0008%である。Ca含有量の上限は、好ましくは0.0035%であり、さらに好ましくは0.0030%である。
銅(Cu)は、鋼の焼入れ性を高め、鋼の強度を高める。Cu含有量が0.1%未満では、この効果が十分に得られない。一方、Cu含有量が1.0%よりも高ければ、鋼の溶接性が低下する。Cu含有量が高すぎればさらに、高温における鋼の粒界強度が低下し、鋼の熱間加工性が低下する。したがって、Cu含有量は0.1~1.0%である。Cu含有量の下限は、好ましくは0.12%であり、さらに好ましくは0.15%である。Cu含有量の上限は、好ましくは0.5%であり、さらに好ましくは0.3%であり、さらに好ましくは0.2%である。
ニッケル(Ni)は、鋼の焼入れ性を高め、鋼の強度を高める。Niはまた、焼入れ性を高める元素であるにもかかわらず、溶接性への悪影響が小さい。Niはさらに、鋼の靱性も向上する。Niが0.2%未満では、これらの効果が十分に得られない。一方、Ni含有量が1.0%よりも高ければ、耐SSC性が低下する。したがって、Ni含有量は0.2~1.0%である。Ni含有量の下限は、好ましくは0.3%であり、さらに好ましくは0.35%であり、さらに好ましくは0.4%である。Ni含有量の上限は、好ましくは0.9%であり、さらに好ましくは0.8%である。
ニオブ(Nb)は、鋼中のC及び/又はNと結合して微細なNb炭化物を形成し、鋼の強度及び靱性を高める。Nbはさらに、Mo炭化物中に固溶し、Mo炭化物の粗大化を抑制する。Nbが少しでも含有されていれば、上記の効果が得られる。一方、Nb含有量が0.05%よりも高ければ、炭化物が粗大化し、鋼の靱性が低下する。したがって、Nb含有量は0~0.05%である。Nb含有量の下限は、好ましくは0.005%である。Nb含有量の上限は、好ましくは0.04%であり、さらに好ましくは0.03%である。
C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5×B≦0.28 式(1)
式(1)の元素記号には、質量%で、対応する元素の含有量が代入される。
Ceq=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15 式(2)
式(2)の元素記号には、質量%で、対応する元素の含有量が代入される。
本実施形態による高強度継目無鋼管は、好ましくは555MPa以上の降伏強度と、625MPa以上の引張強度とを有する。本実施形態による高強度継目無鋼管は、より好ましくは600MPa以上の降伏強度と、670MPa以上の引張強度とを有する。
以下、本実施形態による高強度継目無鋼管の製造方法の一例を説明する。ただし、本実施形態による高強度継目無鋼管の製造方法は、これに限定されない。
TP=(T+273)×(20+log(t))
式中、Tは℃で表した焼戻し温度であり、tは時間で表した焼戻し時間であり、log(t)はtの常用対数である。
焼戻し後の各継目無鋼管から硬度測定用試験片を採取し、JIS Z 2244に準拠して硬度を測定した。鋼管の内面から1mmの位置の硬度、及び鋼管の外面から1mmの位置の硬度の高い方を、表2の「表層」の欄に示す。また、肉厚中央で測定した4点の平均硬度を、表2の「肉中」の欄に示す。「表層」の値と「肉中」の値の差を、表2の「差」の欄に示す。
焼戻し後の各継目無鋼管から、ASTM E8/E8Mに規定された弧状試験片(幅38.1mm、標点距離50.8mm)を、試験片の長辺が鋼管の長手方向(L方向)に平行になるように採取した。採取した試験片を用いて、引張試験を常温(25℃)の大気中で実施し、降伏応力及び引張強度を求めた。降伏応力は、0.5%全伸び法によって求めた。降伏応力を表2の「YS」の欄に、引張強度を「TS」の欄に、それぞれ示す。
焼戻し後の各継目無鋼管から、内面を含む試験片、肉厚中央を含む試験片、及び外面を含む試験片を採取した。各試験片は、厚さ30mm、幅(円周方向)20mm、長さ100mmであった。NACE TM0284-2003にしたがって、各試験片の耐HIC性を評価した。試験浴は、1atmの硫化水素ガスを飽和させた常温の5%食塩+0.5%酢酸水溶液であった。浸漬してから96時間経過後、各試験片を長手方向に3等分に切断し、割れの有無を目視で確認した。さらに、鋼管の内面を含む試験片に対し、超音波探傷によって割れの有無を確認した。
焼戻し後の各継目無鋼管から、内面を含む試験片、肉厚中央を含む試験片、及び外面を含む試験片を採取した。各試験片は、厚さ2mm、幅(円周方向)20mm、長さ100mmであった。これらの試験片を、上述したHIC試験と同じNACE試験浴に、降伏強度の90%の応力を負荷した状態で720時間浸漬した。浸漬後の試験片の割れの有無を調査した。
焼戻し後の各継目無鋼管を用いて円周溶接継手を作製し、HAZ硬さ試験を実施した。開先形状は5°狭開先、溶接プロセスはGMAW(ガスメタルアーク溶接)とし、溶接条件として、溶接時の入熱量は1.0kJ/mm、予熱/層間温度は200~250℃、シールドガスはダイアルゴン(80体積%Ar+20体積%CO2)とした。
製造した鋼管の靱性を、シャルピー衝撃試験によって確認した。鋼管の肉厚中央部付近から、試験片の長辺が鋼管の長手方向(L方向)と平行になるように断面10×10mm(ノッチ部では10×8mm)の2mmVノッチ試験片を採取し、-40℃にて試験を実施した。結果を表2の「吸収エネルギー」の欄に示す。このシャルピー衝撃試験において、100Jを越える吸収エネルギーを示した材料は高靱性であると判定した。
表2に示すように、本実施形態の好適な条件を満たす鋼種1、鋼種2、及び鋼種10からそれぞれ製造したItemA、ItemB、及びItemLは、降伏強度が555MPa以上、引張強度が625MPa以上であり、かつ表層の硬度が250Hv以下であった。ItemA、ItemB、及びItemLではさらに、同一断面における硬度のばらつき(表層の硬度と内厚中央の硬度との差)が15Hv以下であった。さらに、ItemA、ItemB、及びItemLでは、最高HAZ硬さが250Hv以下であった。またシャルピー衝撃試験においても100Jを越える吸収エネルギーであり高靱性であった。
鋼種1~10のそれぞれについて、焼戻し条件を変えながら継目無鋼管を製造し、降伏強度、引張強度、表層の硬度を測定した。測定値から、焼戻しパラメータTPとこれらの特性との関係を回帰分析によって求めた。そして、降伏強度が555MPa以上、引張強度が625MPa以上、表層の硬度が250Hv以下という3つの条件をすべて満たすTPの範囲(許容TP幅)を求めた。
許容TP幅=TPMAX-TPMIN
Claims (5)
- 化学組成が、質量%で、
C :0.10~0.18%、
Si:0.03~1.0%、
Mn:0.5~2.0%、
P :0.020%以下、
S :0.0080%以下、
Cr:0.10~0.60%、
Mo:0.10~0.40%、
V :0.02~0.40%、
Ti:0.004~0.020%、
B :0.0005~0.005%、
Al:0.10%以下、
N :0.008%以下、
Ca:0.0004~0.0040%、
Cu:0.1~1.0%、
Ni:0.2~1.0%、
Nb:0~0.05%、
残部:Fe及び不純物であり、
下記の式(1)を満たす、高強度継目無鋼管。
C+Si/30+(Mn+Cu+Cr)/20+Ni/60+Mo/15+V/10+5×B≦0.28 式(1)
式(1)の元素記号には、質量%で、対応する元素の含有量が代入される。 - 請求項1に記載の高強度継目無鋼管であって、
前記化学組成が、質量%で、
Nb:0.005~0.05%、
を含有する、高強度継目無鋼管。 - 請求項1又は2に記載の高強度継目無鋼管であって、
30mm以上の肉厚を有し、
555MPa以上の降伏強度と、625MPa以上の引張強度とを有し、
表層の硬度が250Hv以下である、高強度継目無鋼管。 - 請求項1~3のいずれか一項に記載の高強度継目無鋼管であって、
管軸方向に垂直な断面における硬度ばらつきが15Hv以下である、高強度継目無鋼管。 - 請求項1~4のいずれか一項に記載の高強度継目無鋼管からなるライザー。
Priority Applications (4)
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EP17833981.8A EP3492612A4 (en) | 2016-07-28 | 2017-07-05 | STAINLESS STEEL PIPE AND COLUMN WITHOUT WELDING OF HIGH STRENGTH |
BR112018015533-0A BR112018015533A2 (ja) | 2016-07-28 | 2017-07-05 | High intensity seamless steel tubes and riser |
MX2018011404A MX2018011404A (es) | 2016-07-28 | 2017-07-05 | Tubo de acero sin costura de resistencia alta y tubo ascendente. |
JP2018529468A JP6642715B2 (ja) | 2016-07-28 | 2017-07-05 | 高強度継目無鋼管及びライザー |
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JP2019127620A (ja) * | 2018-01-25 | 2019-08-01 | 日本製鉄株式会社 | 高強度継目無鋼管及びジャッキアップリグのブレーシングパイプ |
CN111187982A (zh) * | 2020-02-17 | 2020-05-22 | 本钢板材股份有限公司 | 低屈强比螺旋焊管钢A139Gr.B及其制备方法 |
WO2024071422A1 (ja) * | 2022-09-30 | 2024-04-04 | 日本製鉄株式会社 | 鋼板 |
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EP3492612A4 (en) | 2019-08-07 |
BR112018015533A2 (ja) | 2018-12-26 |
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