WO2017150251A1 - 鋼材及び油井用鋼管 - Google Patents
鋼材及び油井用鋼管 Download PDFInfo
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- WO2017150251A1 WO2017150251A1 PCT/JP2017/006151 JP2017006151W WO2017150251A1 WO 2017150251 A1 WO2017150251 A1 WO 2017150251A1 JP 2017006151 W JP2017006151 W JP 2017006151W WO 2017150251 A1 WO2017150251 A1 WO 2017150251A1
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
- F16L9/00—Rigid pipes
- F16L9/02—Rigid pipes of metal
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B1/00—Layered products having a general shape other than plane
- B32B1/08—Tubular products
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- B—PERFORMING OPERATIONS; TRANSPORTING
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- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
- B32B15/011—Layered products comprising a layer of metal all layers being exclusively metallic all layers being formed of iron alloys or steels
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
- B32B15/013—Layered products comprising a layer of metal all layers being exclusively metallic one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium
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- Y10T428/12972—Containing 0.01-1.7% carbon [i.e., steel]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12861—Group VIII or IB metal-base component
- Y10T428/12951—Fe-base component
- Y10T428/12972—Containing 0.01-1.7% carbon [i.e., steel]
- Y10T428/12979—Containing more than 10% nonferrous elements [e.g., high alloy, stainless]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/13—Hollow or container type article [e.g., tube, vase, etc.]
Definitions
- the present invention relates to a steel material and an oil well steel pipe, and more particularly to a steel material and an oil well steel pipe suitable for use in a sour environment.
- oil wells and gas wells By making deep wells in oil wells and gas wells (hereinafter, oil wells and gas wells are simply referred to as “oil wells”), it is required to increase the strength of steel pipes for oil wells.
- steel pipes for oil wells of 80 ksi class yield stress is 80 to 95 ksi, that is, 551 to 654 MPa
- 95 ksi class yield stress is 95 to 110 ksi, that is, 654 to 758 MPa
- SSC resistance resistance to sulfide stress cracking
- Patent Document 1 Steels having high strength and enhanced hydrogen embrittlement resistance (SSC resistance, delayed fracture resistance) are disclosed in JP-A-56-5949 (Patent Document 1) and JP-A-57-35622. It is proposed in the publication (Patent Document 2). The steel disclosed in these documents enhances the hydrogen embrittlement resistance (SSC resistance, delayed fracture resistance) by containing Co.
- the high-tensile steel disclosed in Patent Document 1 is C: 0.05 to 0.50%, Si: 0.10 to 0.28%, Mn: 0.10 to 2.0%, Co: 0.05 to 1.50%, Al: 0.01 to 0.10%, with the balance being quenched and tempered steel having a chemical composition consisting of Fe and inevitable impurities, 60 kg / mm 2 or more Has proof stress.
- the high-strength oil well steel disclosed in Patent Document 2 is C: 0.27 to 0.50%, Si: 0.08 to 0.30%, Mn: 0.90 to 1.30%, Cr: 0 0.5 to 0.9%, Ni: 0.03% or less, V: 0.04 to 0.11%, Nb: 0.01 to 0.10%, Mo: 0.60 to 0.80%, Al : Steel containing 0.1% or less and Co: 3% or less, the balance being Fe and unavoidable impurities, P having a chemical composition of P: 0.005% or less, S: 0.003% or less Is quenched at 880 to 980 ° C. and then tempered at 650 to 700 ° C.
- the evaluation of SSC resistance of conventional steel materials is mainly based on a tensile test or a bending test such as a Method A test or a Method B test defined in NACE (National Association of Corrosion Engineers) TM0177. .
- Patent Document 1 and Patent Document 2 do not evaluate the SSC resistance in a high pressure H 2 S environment where the H 2 S partial pressure is 5 to 15 atm, and the fracture toughness value K ISSC in a high pressure H 2 S environment. May be low.
- An object of the present invention is to provide a steel material having excellent SSC resistance even in a high-pressure H 2 S environment.
- the steel material according to the present invention is, in mass%, C: 0.15 to 0.45%, Si: 0.10 to 1.0%, Mn: 0.10 to less than 0.90%, P: 0.05%
- B 0 to 0.003%
- Ca: 0 to 0.004%, Mg: 0 to 0.004%, Zr: 0 to 0.004%, and rare earth elements: 0 to 0.004% is contained, the balance consists of Fe and impurities, has a chemical composition satisfying the formulas (1) and (2), and the microstructure contains tempered martensite with a volume ratio of 90% or more.
- the steel material according to the present invention has excellent SSC resistance even in a high-pressure H 2 S environment.
- FIG. 1 is a diagram showing the relationship between the Co content (% by mass) and the fracture toughness value K ISSC (unit: MPa ⁇ m).
- FIG. 3A is a side view and a cross-sectional view of a DCB test piece used in the DCB test of the example. The numerical value in FIG. 3A shows the dimension (a unit is mm) of a corresponding site
- FIG. 3B is a perspective view of a wedge used in the DCB test of the example. The numerical value in FIG. 3B shows the dimension (a unit is mm) of a corresponding site
- the present inventors investigated and examined the SSC resistance under a high pressure H 2 S environment of 5 to 15 atm and obtained the following knowledge.
- Co enhances SSC resistance.
- C 0.15 to 0.45%
- Si 0.10 to 1.0%
- Mn 0.10 to less than 0.90%
- P 0.05% or less
- S 0.01% or less
- Al 0.01 to 0.1%
- N 0.010% or less
- Cr 0.1 to 2.5%
- Mo 0.35 to 3.0%
- Cu 0 -0.5%
- Ti 0-0.03%
- Nb 0-0.15%
- V 0-0.5%
- B 0-0.003%
- the Co content is 0.50% to 3.0%, excellent SSC resistance can be obtained.
- FIG. 1 is a diagram showing the relationship between the Co content (mass%) in a high-pressure H 2 S environment and the fracture toughness value K ISSC (unit: MPa ⁇ m) obtained in the DCB test of the examples described later. is there.
- the fracture toughness value K ISSC unit: MPa ⁇ m
- FIG. 1 is a diagram showing the relationship between the Co content (mass%) in a high-pressure H 2 S environment and the fracture toughness value K ISSC (unit: MPa ⁇ m) obtained in the DCB test of the examples described later. is there.
- the Co content increases from 0%, the fracture toughness value K ISSC increases rapidly, and when the Co content is 0.50% or more, it becomes 35 MPa ⁇ m or more.
- the fracture toughness value K ISSC decreases, but when the Co content exceeds 1.0%, the fracture toughness value K is reached until the Co content reaches 3.0%.
- the ISSC remains almost constant at a value higher than 35 MPa ⁇ m.
- the fracture toughness value K ISSC gradually decreases
- F1 C + Mn / 6 + (Cr + Mo + V) / 5 + (Cu + Ni) / 15 ⁇ Co / 6 + ⁇ .
- F1 is an index of hardenability.
- C, Mn, Cr, Mo, V, Cu and a predetermined amount of effective B (solid solution B) enhance the hardenability of the steel.
- B solid solution B
- Co lowers the hardenability of steel. If F1 is 0.50 or more, even if Co is contained, excellent hardenability is obtained, and the volume ratio of tempered martensite in the microstructure can be increased.
- the microstructure When the microstructure is substantially composed of tempered martensite, excellent SSC resistance can be obtained. On the other hand, when the microstructure is a non-uniform structure composed of tempered martensite and other phases (bainite, retained austenite, etc.), the SSC resistance decreases. When F1 satisfies Formula (1), the volume ratio of tempered martensite in the microstructure is 90% or more, and excellent SSC resistance is obtained.
- F2 (3C + Mo + 3Co) / (3Mn + Cr).
- F2 is an index of SSC resistance.
- FIG. 2 is a diagram showing the relationship between F2 and the fracture toughness value K ISSC (unit: MPa ⁇ m).
- FIG. 2 was obtained in a DCB test on a steel plate corresponding to API standard C110 grade in Examples described later.
- F2 when F2 is around 1.0, fracture toughness value K ISSC increases rapidly.
- the steel material according to the present invention completed based on the above knowledge is, in mass%, C: 0.15 to 0.45%, Si: 0.10 to 1.0%, Mn: 0.10 to less than 0.90. %, P: 0.05% or less, S: 0.01% or less, Al: 0.01 to 0.1%, N: 0.010% or less, Cr: 0.1 to 2.5%, Mo: 0.35 to 3.0%, Co: 0.50 to 3.0%, Cu: 0 to 0.5%, Ni: 0 to 0.5%, Ti: 0 to 0.03%, Nb: 0 ⁇ 0.15%, V: 0 ⁇ 0.5%, B: 0 ⁇ 0.003%, Ca: 0 ⁇ 0.004%, Mg: 0 ⁇ 0.004%, Zr: 0 ⁇ 0.004% And a rare earth element: 0 to 0.004%, the balance being Fe and impurities, having a chemical composition satisfying the formulas (1) and (2), and having a microstructure with a volume ratio of 90% or more Tempered Martensa Characterized in that
- Effective B B-11 (N-Ti / 3.4) / 14 (3)
- ⁇ in the formula (1) is 0.250 when the effective B (% by mass) defined by the formula (3) is 0.0003% or more, and the effective B is less than 0.0003%. Is 0. The content (mass%) of the corresponding element is substituted for each element symbol in the expressions (1) to (3).
- the chemical composition may contain one or more selected from the group consisting of Cu: 0.02 to 0.5% and Ni: 0.02 to 0.5%.
- the chemical composition is one or two selected from the group consisting of Ti: 0.003-0.03%, Nb: 0.003-0.15%, and V: 0.005-0.5%. It may contain seeds or more.
- the above chemical composition may contain B: 0.0003 to 0.003%.
- the chemical composition is Ca: 0.0003 to 0.004%, Mg: 0.0003 to 0.004%, Zr: 0.0003 to 0.004%, and rare earth elements: 0.0003 to 0.004.
- You may contain 1 type, or 2 or more types selected from the group which consists of%.
- the oil well steel pipe according to the present invention has excellent strength and SSC resistance even if it has a wall thickness of 15 mm or more as long as it has the above chemical composition.
- C 0.15-0.45% Carbon (C) increases the hardenability and increases the strength of the steel. C further promotes the spheroidization of carbides during tempering during the manufacturing process and enhances SSC resistance. C further combines with Mo or V to form carbides and increases temper softening resistance. If the carbide is dispersed, the strength of the steel is further increased. If the C content is too low, these effects cannot be obtained. On the other hand, if the C content is too high, the toughness of the steel is lowered and fire cracks are likely to occur. Therefore, the C content is 0.15 to 0.45%. The minimum with preferable C content is 0.20%, More preferably, it is 0.25%. The upper limit with preferable C content is 0.40%, More preferably, it is 0.35%.
- Si 0.10 to 1.0% 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, excessive austenite is generated and the SSC resistance is lowered. Therefore, the Si content is 0.10 to 1.0%.
- the minimum of preferable Si content is 0.15%, More preferably, it is 0.20%.
- the upper limit of the preferred Si content is 0.55%, more preferably 0.40%.
- Mn 0.10 to less than 0.90%
- Manganese (Mn) deoxidizes steel. Mn further increases the hardenability and increases the strength of the steel. If the Mn content is too low, these effects cannot be obtained. On the other hand, if the Mn content is too high, Mn segregates at grain boundaries together with impurities such as phosphorus (P) and sulfur (S). In this case, the SSC resistance of the steel decreases. Therefore, the Mn content is 0.10 to less than 0.90%.
- the minimum of preferable Mn content is 0.25%, More preferably, it is 0.28%.
- the upper limit of the preferable Mn content is 0.80%.
- P 0.05% or less Phosphorus (P) is an impurity. P segregates at the grain boundaries and lowers the SSC resistance of the steel. Therefore, the P content is 0.05% or less. A preferable P content is 0.02% or less. The P content is preferably as low as possible.
- S 0.01% or less Sulfur (S) is an impurity. S segregates at the grain boundaries and lowers the SSC resistance of the steel. Therefore, the S content is 0.01% or less. A preferable S content is 0.005% or less, and more preferably 0.003% or less. The S content is preferably as low as possible.
- Al 0.01 to 0.1%
- Aluminum (Al) deoxidizes steel. If the Al content is too low, this effect cannot be obtained and the SSC resistance of the steel decreases. On the other hand, if the Al content is too high, coarse oxide inclusions are generated and the SSC resistance of the steel is lowered. Therefore, the Al content is 0.01 to 0.1%.
- the minimum with preferable Al content is 0.015%, More preferably, it is 0.020%.
- the upper limit with preferable Al content is 0.06%, More preferably, it is 0.050%.
- Al content means “acid-soluble Al”, that is, the content of “sol. Al”.
- N 0.010% or less Nitrogen (N) is inevitably contained. N forms coarse nitrides and lowers the SSC resistance of the steel. Therefore, the N content is 0.010% or less. A preferable N content is 0.005% or less, and more preferably 0.004% or less. The N content is preferably as low as possible. However, in the case where a slight amount of Ti is contained and the aim is to refine crystal grains by precipitation of fine nitride, it is preferable to contain N in an amount of 0.002% or more.
- Chromium (Cr) increases the hardenability of the steel and increases the strength of the steel. If the Cr content is too low, the above effect cannot be obtained. On the other hand, if the Cr content is too high, the SSC resistance of the steel decreases. Therefore, the Cr content is 0.1 to 2.5%.
- the minimum with preferable Cr content is 0.25%, More preferably, it is 0.30%.
- the upper limit with preferable Cr content is 1.5%, More preferably, it is 1.3%.
- Mo 0.35 to 3.0% Molybdenum (Mo) increases the hardenability of the steel. Mo further generates fine carbides, increases the temper softening resistance of the steel, and increases the SSC resistance in a high-pressure H 2 S environment. If the Mo content is too low, this effect cannot be obtained. On the other hand, if the Mo content is too high, the above effect is saturated. Therefore, the Mo content is 0.35 to 3.0%.
- the minimum with preferable Mo content is 0.40%, More preferably, it is 0.50%, More preferably, it is more than 0.70%.
- the upper limit with preferable Mo content is 2.0%, More preferably, it is 1.75%.
- Co 0.50 to 3.0%
- Cobalt (Co) enhances the SSC resistance of steel in a high pressure H 2 S environment. The reason for this is not clear, but the following reasons can be considered. Co is concentrated on the surface of steel in a sour environment, and suppresses the penetration of hydrogen into the steel. This increases the SSC resistance of the steel. If the Co content is too low, this effect cannot be obtained. On the other hand, if the Co content is too high, the hardenability of the steel decreases and the strength of the steel decreases. Therefore, the Co content is 0.50 to 3.0%.
- the minimum with preferable Co content is more than 0.50%, More preferably, it is 0.7%, More preferably, it is 1.0%.
- the upper limit with preferable Co content is 2.5%, More preferably, it is 2.0%.
- the balance of the chemical composition of the steel material according to the present invention consists of Fe and impurities.
- the impurities are mixed from ore as a raw material, scrap, or production environment when industrially producing steel materials, and are allowed within a range that does not adversely affect the steel materials of the present invention. Means something.
- the chemical composition of the steel material described above may further include one or more selected from the group consisting of Cu and Ni instead of part of Fe. All of these elements are optional elements and increase the strength of the steel.
- Cu 0 to 0.5% Copper (Cu) is an optional element and may not be contained. When contained, Cu increases the hardenability of the steel and increases the strength of the steel. However, if the Cu content is too high, hydrogen is trapped, and the SSC resistance is lowered. Therefore, the Cu content is 0 to 0.5%.
- the minimum with preferable Cu content is 0.02%, More preferably, it is 0.05%.
- the upper limit with preferable Cu content is 0.35%, More preferably, it is 0.25%.
- Nickel (Ni) is an optional element and may not be contained. When contained, Ni increases the hardenability of the steel and increases the strength of the steel. However, if the Ni content is too high, local corrosion is promoted and the SSC resistance is lowered. Therefore, the Ni content is 0 to 0.5%.
- the minimum with preferable Ni content is 0.02%, More preferably, it is 0.05%.
- the upper limit with preferable Ni content is 0.35%, More preferably, it is 0.25%.
- the chemical composition of the steel material described above may further include one or more selected from the group consisting of Ti, Nb and V in place of part of Fe. All of these elements are optional elements, and form at least one of carbide, nitride, and carbonitride to increase the strength of the steel.
- Titanium (Ti) is an optional element and may not be contained. When contained, Ti forms a nitride and refines the crystal grains by the pinning effect. This increases the strength of the steel. However, if the Ti content is too high, the Ti nitride becomes coarse and the SSC resistance of the steel decreases. Therefore, the Ti content is 0 to 0.03%.
- the minimum with preferable Ti content is 0.003%, More preferably, it is 0.005%.
- the upper limit with preferable Ti content is 0.015%, More preferably, it is 0.012%.
- Niobium (Nb) is an optional element and may not be contained. When contained, Nb combines with C and / or N to form a carbide, nitride or carbonitride (hereinafter referred to as carbonitride or the like). These carbonitrides etc. refine crystal grains and increase the strength of steel. However, if the Nb content is too high, coarse precipitates are generated and the SSC resistance of the steel is reduced. Therefore, the Nb content is 0 to 0.15%. The minimum with preferable Nb content is 0.003%, More preferably, it is 0.007%. The upper limit with preferable Nb content is 0.050%, More preferably, it is 0.04%.
- V 0 to 0.5%
- Vanadium (V) is an optional element and may not be contained. When contained, V forms carbonitride and the like, refines the crystal grains, and increases the strength of the steel. However, if the V content is too high, the toughness of the steel decreases. Therefore, the V content is 0 to 0.5%.
- the minimum with preferable V content is 0.005%, More preferably, it is 0.015%.
- the upper limit with preferable V content is 0.15%, More preferably, it is 0.12%.
- the chemical composition of the above steel material may further contain B instead of a part of Fe.
- B 0 to 0.003%
- Boron (B) is an optional element and may not be contained. When contained, B dissolves in the steel to increase the hardenability of the steel and increase the strength. However, if the B content is too high, coarse nitrides are produced and the SSC resistance of the steel is reduced. Therefore, the B content is 0 to 0.003%.
- the minimum with preferable B content is 0.0003%, More preferably, it is 0.0007%.
- the upper limit with preferable B content is 0.0015%, More preferably, it is 0.0012%.
- the chemical composition of the steel material described above may further include one or more selected from the group consisting of Ca, Mg, Zr, and rare earth elements instead of a part of Fe. Any of these elements is an arbitrary element, and improves the SSC resistance of the steel by improving the shape of the sulfide.
- Ca 0 to 0.004%
- Calcium (Ca) is an optional element and may not be contained.
- Ca combines with S in the steel.
- the sulfide in steel refines
- the Ca content is 0 to 0.004%.
- the minimum with preferable Ca content is 0.0003%, More preferably, it is 0.0006%.
- the upper limit with preferable Ca content is 0.0025%, More preferably, it is 0.0020%.
- Mg 0 to 0.004%
- Magnesium (Mg) is an optional element and may not be contained.
- Mg refines sulfides in the steel to improve the SSC resistance of the steel.
- the Mg content is 0 to 0.004%.
- the minimum with preferable Mg content is 0.0003%, More preferably, it is 0.0006%.
- the upper limit with preferable Mg content is 0.0025%, More preferably, it is 0.0020%.
- Zr Zirconium
- Zr Zirconium
- Zr refines sulfides in the steel to improve the SSC resistance of the steel.
- the Zr content is 0 to 0.004%.
- the minimum with preferable Zr content is 0.0003%, More preferably, it is 0.0006%.
- the upper limit with preferable Zr content is 0.0025%, More preferably, it is 0.0020%.
- the rare earth element is an optional element and may not be contained.
- REM refines sulfides in the steel to increase the SSC resistance of the steel.
- REM further combines with P in the steel to suppress P segregation at the grain boundaries. For this reason, a decrease in the SSC resistance of the steel due to the segregation of P is suppressed.
- the REM content is 0 to 0.004%.
- the minimum with preferable REM content is 0.0003%, More preferably, it is 0.0006%.
- the upper limit with preferable REM content is 0.0025%, More preferably, it is 0.0020%.
- REM in the present specification contains at least one of Sc, Y, and lanthanoid (La of atomic number 57 to Lu of 71), and the REM content means the total content of these elements To do.
- F1 C + Mn / 6 + (Cr + Mo + V) / 5 + (Cu + Ni) / 15 ⁇ Co / 6 + ⁇ .
- F1 is an index of hardenability. If F1 is 0.50 or more, excellent hardenability can be obtained even if Co is contained, and the volume ratio of tempered martensite in the microstructure becomes 90% or more. As a result, excellent SSC resistance can be obtained.
- a preferred lower limit of F1 is 0.70.
- F2 (3C + Mo + 3Co) / (3Mn + Cr).
- F2 is an index of SSC resistance.
- the content of SSC resistance improving elements C, Mo and Co
- the content of Mn and Cr distributed to hardenability, but excessive content decreases SSC resistance
- the ratio to the element obtained is increased. As a result, excellent SSC resistance in a high-pressure H 2 S environment can be obtained.
- the microstructure of the steel material of the present invention is mainly composed of tempered martensite. More specifically, the microstructure is tempered martensite having a volume ratio of 90% or more. The balance of the microstructure is, for example, bainite, retained austenite or the like. If the microstructure contains tempered martensite having a volume ratio of 90% or more, the SSC resistance is enhanced. Preferably, the microstructure consists of a tempered martensite single phase.
- the volume ratio of tempered martensite in the microstructure correlates with the difference between the maximum value and the minimum value of Rockwell hardness (HRC) in the steel material after quenching and tempering.
- HRC Rockwell hardness
- the maximum value of Rockwell hardness after quenching and tempering is defined as HRCmax.
- the minimum value of Rockwell hardness after quenching and tempering is defined as HRCmin.
- the difference between HRCmax and HRCmin is defined as ⁇ HRC.
- ⁇ HRC HRCmax ⁇ HRCmin If ⁇ HRC is less than 2.0, the volume ratio of tempered martensite in the microstructure of the steel material is considered to be 90% or more.
- the Rockwell hardness at the steel surface is HRCmax
- the Rockwell hardness at the steel thickness central portion (hereinafter referred to as the steel central portion) is HRCmin.
- the reason for this is as follows.
- the cooling rate during quenching cooling is fast on the steel surface and slows at the center of the steel. Therefore, in the as-quenched steel material, the difference in the volume ratio of martensite may be large between the steel material surface and the steel material central part. Since the volume ratio of martensite in the microstructure correlates with the Rockwell hardness, in this case, the difference in as-quenched Rockwell hardness increases between the steel material surface and the steel material central part.
- the hardness decreases on both the steel surface and the steel center, and the difference in Rockwell hardness between the steel surface and the steel center decreases, but the steel surface and the steel center The difference in Rockwell hardness between the parts remains. Therefore, the Rockwell hardness at the steel surface is HRCmax, and the Rockwell hardness at the steel center is HRCmin. If ⁇ HRC is 2.0 or more, the hardness of the steel material center is too low. If ⁇ HRC is less than 2.0, sufficient hardness is obtained even in the central part of the steel material. In this case, the volume ratio of tempered martensite in the central part of the steel material is considered to be 90% or more.
- ⁇ HRC is measured by the following method. 2.0 mm depth position from the surface (outer surface in the case of a steel pipe) of the steel material after quenching and tempering treatment, 2.0 mm depth position from the back surface (inner surface in the case of a steel pipe) of the steel material, and the thickness direction center of the steel material At each of the positions, a Rockwell hardness test (C scale) in accordance with JIS Z2245 (2011) is performed at any three locations to determine Rockwell hardness (HRC). If the maximum value of hardness obtained is HRCmax, the minimum value is HRCmin, and ⁇ HRC is less than 2.0, it is determined that the volume ratio of tempered martensite is 90% or more. If ⁇ HRC is 2.0 or more, it is determined that the volume ratio of tempered martensite is less than 90% at the position of HRCmin.
- the shape of the steel material is not particularly limited.
- the steel material is, for example, a steel pipe or a steel plate.
- the preferred thickness is 9 to 60 mm.
- the present invention is particularly suitable for use as a thick-walled oil well steel pipe. More specifically, even if the steel material according to the present invention is a steel pipe for oil well with a thickness of 15 mm or more, and further 20 mm or more, excellent strength and SSC resistance are exhibited.
- a preferable lower limit of the yield strength of the steel material is 654 MPa.
- the upper limit of the yield strength of the steel material is 860 MPa.
- the yield strength as used in this specification means a lower yield point (MPa).
- the manufacturing method of steel pipes for oil wells includes the process of preparing the raw material (preparation process), the process of hot working the raw material to manufacture the raw pipe (hot working process), and quenching and tempering the raw pipe And a step (quenching step and tempering step) for making the oil well steel pipe.
- preparation process the process of preparing the raw material
- hot working process the process of hot working the raw material to manufacture the raw pipe
- quenching and tempering the raw pipe quenching and tempering step
- fills Formula (1) and Formula (2) is manufactured.
- the material is manufactured using molten steel.
- a slab slab, bloom, or billet
- the billet may be produced by rolling the slab, bloom or ingot into pieces.
- the material (slab, bloom, or billet) is manufactured by the above process.
- the raw material is manufactured by hot working the prepared material.
- the billet is heated in a heating furnace.
- the billet extracted from the heating furnace is hot-worked to produce a raw pipe (seamless steel pipe).
- the Mannesmann method is performed as hot working to manufacture a raw tube.
- the round billet is pierced and rolled by a piercing machine.
- the round billet that has been pierced and rolled is further hot-rolled by a mandrel mill, a reducer, a sizing mill, or the like into a blank tube.
- the blank tube may be manufactured from the billet by other hot working methods.
- the raw pipe may be manufactured by forging. Through the above steps, a blank tube having a thickness of 9 to 60 mm is manufactured.
- the raw tube manufactured by hot working may be air-cooled (As-Rolled). Steel pipes manufactured by hot working can also be directly quenched after hot pipe making without cooling to room temperature, or after being reheated after hot pipe making and quenching. Good. However, when quenching directly after quenching or after supplementary heating, it is preferable to stop cooling during quenching or to perform slow cooling for the purpose of suppressing quench cracking.
- the purpose of removing residual stress is to perform stress relief annealing after quenching and before heat treatment in the next process. It is preferable to perform processing (SR processing).
- SR processing processing
- Quenching process Quenching is performed on the blank after hot working.
- a preferable quenching temperature is 850 to 1000 ° C.
- forced cooling at a cooling rate of 5 ° C./second or more is started before the temperature at the latest cooling point becomes equal to or lower than the Ar 3 temperature. In this case, it is easy to further increase the yield strength.
- Quenching treatment may be performed multiple times.
- SR treatment can prevent the occurrence of cracks after quenching.
- a preferable processing temperature is 600 degrees C or less. In this case, coarsening of austenite can be suppressed.
- Tempeering process A tempering process is implemented after implementing the above-mentioned hardening process. The yield strength of the steel is adjusted by tempering. A preferred lower limit of the tempering temperature is 650 ° C. The upper limit with preferable tempering temperature is 730 degreeC.
- the manufacturing method described above a method for manufacturing a steel pipe has been described as an example.
- the steel material of this invention is a steel plate and another shape
- the manufacturing method of a steel plate is similarly equipped with a preparation process, a hot working process, a quenching process, and a tempering process.
- An ingot was manufactured using the above molten steel.
- the ingot was hot rolled to produce a steel plate.
- the thickness (mm) of the steel sheet was as shown in Table 2.
- Yield Strength (YS) and Tensile Strength (TS) Test A round bar tensile test piece having a diameter of 6.35 mm and a parallel part length of 35 mm was prepared from the center of the thickness of each steel plate after the quenching and tempering treatments. The axial direction of the tensile specimen was parallel to the rolling direction of the steel plate. Using each round bar test piece, a tensile test was carried out at normal temperature (25 ° C.) and in the atmosphere to obtain yield strength (YS) (MPa) and tensile strength (TS) (MPa) at each position. In this example, the yield point obtained by the tensile test was defined as the yield strength (YS) of each test number.
- DCB test Each steel plate was subjected to a DCB test in accordance with NACE TM0177-96 Method D to evaluate SSC resistance. Specifically, three DCB test pieces shown in FIG. 3A were collected from the thickness center of each steel plate. Further, the wedge shown in FIG. 3B was produced from the steel plate. The wedge thickness t was 2.92 mm. In addition, the numerical value in FIG. 3A and 3B shows the dimension (a unit is mm) of a corresponding site
- a wedge was driven between the arms of the DCB test piece. Thereafter, the DCB test piece into which the wedge was driven was sealed in an autoclave. A solution adjusted to pH 3.5 by mixing degassed 5% saline, acetic acid, and Na acetate was poured into the autoclave so that a gaseous portion remained in the autoclave. Thereafter, 10 atm hydrogen sulfide gas was pressurized and sealed in the autoclave, the liquid phase was stirred, and the high-pressure hydrogen sulfide gas was saturated with the solution.
- the solution was kept at 25 ° C. for 336 hours while stirring. Thereafter, the autoclave was decompressed and the DCB test piece was taken out.
- Equation (4) h is the height (mm) of each arm of the DCB specimen, B is the thickness (mm) of the DCB specimen, and Bn is the web thickness (mm) of the DCB specimen. is there.
- Fracture toughness values K ISSC (MPa ⁇ m) of three DCB test pieces were determined for each test number.
- the average of fracture toughness values of three DCB specimens was defined as the fracture toughness value K ISSC (MPa ⁇ m) of the steel plate.
- the obtained fracture toughness value K ISSC is shown in Table 2.
- Steel plates 1, 2, 10, 11, and 22 are judged to have good SSC resistance when the fracture toughness value K ISSC value defined above is 47 MPa ⁇ m or more. did. In other steels (corresponding to API standard C110 grade), when the above defined fracture toughness value K ISSC value was 35 MPa ⁇ m or more, it was judged that the SSC resistance was good.
- interval of the arm at the time of driving a wedge before being immersed in a test tank affects a KISSC value. Therefore, the distance between the arms was measured with a micrometer, and it was confirmed that it was within the API standard range.
- the chemical compositions of the steel plates 1 to 9 and 22 were appropriate and satisfied the formulas (1) and (2). Furthermore, since ⁇ HRC was less than 2.0, the microstructure determination was acceptable, and the microstructure was martensite with a volume ratio of 90% or more. As a result, K ISSC values of steels 1, 2 and 22 or more 47MPa ⁇ m, K ISSC value of the steel 3-9 becomes more 35MPa ⁇ m, showed excellent SSC resistance.
- the yield strength of steels 1, 2 and 22 was 654 MPa or more, and the yield strengths of steels 3 to 9 were 760 MPa or more.
- F2 was less than the lower limit of formula (2).
- the K ISSC value was less than 47 MPa ⁇ m, and the SSC resistance was low.
- the ratio of the content of the SSC resistance improving elements (C, Mo and Co) to the content of Mn and Cr is too low, and as a result, the SSC resistance is considered to be low.
- the Mo content was low.
- the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the Co content was low.
- the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the Mn content was high.
- the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the Cr content was high.
- the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the Co content was too high, and F1 was less than the lower limit of formula (1). Therefore, the hardenability decreased and ⁇ HRC was 2.0 or more, so the microstructure determination was rejected, and the martensite volume fraction in the microstructure was less than 90%. As a result, the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the C content and the Co content were too high, and F1 was less than the lower limit of formula (1). Therefore, the hardenability decreased and ⁇ HRC was 2.0 or more, so the microstructure determination was rejected, and the martensite volume fraction in the microstructure was less than 90%. As a result, the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the steel plate of Steel 18 did not contain Co, and F2 was less than the lower limit of formula (2). As a result, the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- F2 was less than the lower limit of Formula (2).
- the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the ratio of the content of the SSC resistance improving elements (C, Mo and Co) to the content of Mn and Cr is too low, and as a result, the SSC resistance is considered to be low.
- the Co content was too high. Therefore, the hardenability decreased and ⁇ HRC was 2.0 or more, so the microstructure determination was rejected, and the martensite volume fraction in the microstructure was less than 90%. As a result, the K ISSC value was less than 35 MPa ⁇ m, and the SSC resistance was low.
- the steel material according to the present invention is widely applicable to steel materials used in sour environments, preferably used as oil well steel materials used in oil well environments, and more preferably, casings, tubing, line pipes and the like. It can be used as a steel pipe for oil wells.
Abstract
Description
C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α≧0.50 (1)
(3C+Mo+3Co)/(3Mn+Cr)≧1.0 (2)
有効B=B-11(N-Ti/3.4)/14 (3)
ここで、式(1)のαは、式(3)で定義される有効B(質量%)が0.0003%以上の場合は0.250であり、有効Bが0.0003%未満の場合は0である。式(1)~式(3)中の各元素記号には、対応する元素の含有量(質量%)が代入される。
C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α≧0.50 (1)
(3C+Mo+3Co)/(3Mn+Cr)≧1.0 (2)
有効B=B-11(N-Ti/3.4)/14 (3)
ここで、式(1)のαは、式(3)で定義される有効B(質量%)が0.0003%以上の場合は0.250であり、有効Bが0.0003%未満の場合は0である。式(1)~式(3)中の各元素記号には、対応する元素の含有量(質量%)が代入される。
F1=C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+αと定義する。F1は焼入れ性の指標である。C、Mn、Cr、Mo、V、Cu、及び、所定量の有効B(固溶しているB)は、鋼の焼入れ性を高める。一方、上述のとおり、Coは、鋼の焼入れ性を低くする。F1が0.50以上であれば、Coを含有していても、優れた焼入れ性が得られ、ミクロ組織中の焼戻しマルテンサイトの体積率を高めることができる。
F1が式(1)を満たせば、ミクロ組織が実質的に焼戻しマルテンサイトとなる。しかしながら、合金元素が過剰に含有されれば、鋼材中に水素をトラップする(溜め込む)ため、耐SSC性がかえって低下する。焼入れ性を高める元素のうち、特にMn及びCrは、焼入れ性を高めるものの、耐SSC性を低下しうる。一方、上述のCoとともに、C及びMoは、鋼の耐SSC性を高める元素である。
C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α≧0.50 (1)
(3C+Mo+3Co)/(3Mn+Cr)≧1.0 (2)
有効B=B-11(N-Ti/3.4)/14 (3)
ここで、式(1)のαは、式(3)で定義される有効B(質量%)が0.0003%以上の場合は0.250であり、有効Bが0.0003%未満の場合は0である。式(1)~式(3)中の各元素記号には、対応する元素の含有量(質量%)が代入される。
本発明による鋼材の化学組成は、次の元素を含有する。
炭素(C)は、焼入れ性を高め、鋼の強度を高める。Cはさらに、製造工程中の焼戻し時において、炭化物の球状化を促進し、耐SSC性を高める。Cはさらに、Mo又はVと結合して炭化物を形成し、焼戻し軟化抵抗を高める。炭化物が分散されればさらに、鋼の強度が高まる。C含有量が低すぎれば、これらの効果が得られない。一方、C含有量が高すぎれば、鋼の靭性が低下し、焼割れが発生しやすくなる。したがって、C含有量は0.15~0.45%である。C含有量の好ましい下限は0.20%であり、さらに好ましくは0.25%である。C含有量の好ましい上限は0.40%であり、さらに好ましくは0.35%である。
シリコン(Si)は、鋼を脱酸する。Si含有量が低すぎれば、この効果が得られない。一方、Si含有量が高すぎれば、残留オーステナイトが過剰に生成して耐SSC性が低下する。したがって、Si含有量は、0.10~1.0%である。好ましいSi含有量の下限は、0.15%であり、さらに好ましくは0.20%である。好ましいSi含有量の上限は、0.55%であり、さらに好ましくは0.40%である。
マンガン(Mn)は、鋼を脱酸する。Mnはさらに、焼入れ性を高め、鋼の強度を高める。Mn含有量が低すぎれば、これらの効果が得られない。一方、Mn含量が高すぎれば、Mnは、燐(P)及び硫黄(S)等の不純物とともに、粒界に偏析する。この場合、鋼の耐SSC性が低下する。したがって、Mn含有量は、0.10~0.90未満%である。好ましいMn含有量の下限は、0.25%であり、さらに好ましくは0.28%である。好ましいMn含有量の上限は、0.80%である。
燐(P)は不純物である。Pは、粒界に偏析して鋼の耐SSC性を低下する。したがって、P含有量は、0.05%以下である。好ましいP含有量は0.02%以下である。P含有量はなるべく低い方が好ましい。
硫黄(S)は不純物である。Sは、粒界に偏析して鋼の耐SSC性を低下する。したがって、S含有量は0.01%以下である。好ましいS含有量は0.005%以下であり、さらに好ましくは0.003%以下である。S含有量はなるべく低い方が好ましい。
アルミニウム(Al)は、鋼を脱酸する。Al含有量が低すぎれば、この効果が得られず、鋼の耐SSC性が低下する。一方、Al含有量が高すぎれば、粗大な酸化物系介在物が生成して鋼の耐SSC性が低下する。したがって、Al含有量は0.01~0.1%である。Al含有量の好ましい下限は0.015%であり、さらに好ましくは0.020%である。Al含有量の好ましい上限は0.06%であり、さらに好ましくは0.050%である。本明細書にいう「Al」含有量は「酸可溶Al」、つまり、「sol.Al」の含有量を意味する。
窒素(N)は不可避に含有される。Nは粗大な窒化物を形成して、鋼の耐SSC性を低下する。したがって、N含有量は、0.010%以下である。好ましいN含有量は0.005%以下であり、さらに好ましくは0.004%以下である。N含有量はなるべく低い方が好ましい。ただし、若干量のTiを含有させて、微細窒化物の析出による結晶粒の微細化を狙う場合は、Nを0.002%以上含有させることが好ましい。
クロム(Cr)は、鋼の焼入れ性を高め、鋼の強度を高める。Cr含有量が低すぎれば、上記効果が得られない。一方、Cr含有量が高すぎれば、鋼の耐SSC性が低下する。したがって、Cr含有量は0.1~2.5%である。Cr含有量の好ましい下限は0.25%であり、さらに好ましくは0.30%である。Cr含有量の好ましい上限は1.5%であり、さらに好ましくは1.3%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、微細な炭化物を生成し、鋼の焼戻し軟化抵抗を高め、高圧H2S環境における耐SSC性を高める。Mo含有量が低すぎれば、この効果が得られない。一方、Mo含有量が高すぎれば、上記効果が飽和する。したがって、Mo含有量は0.35~3.0%である。Mo含有量の好ましい下限は0.40%であり、さらに好ましくは0.50%であり、さらに好ましくは0.70超%である。Mo含有量の好ましい上限は2.0%であり、さらに好ましくは1.75%である。
コバルト(Co)は、高圧H2S環境において、鋼の耐SSC性を高める。その理由はさだかではないが、次の理由が考えられる。Coはサワー環境において、鋼の表面に濃化して、鋼中への水素の侵入を抑制する。これにより、鋼の耐SSC性が高まる。Co含有量が低すぎれば、この効果が得られない。一方、Co含有量が高すぎれば、鋼の焼入れ性が低下して、鋼の強度が低くなる。したがって、Co含有量は0.50~3.0%である。Co含有量の好ましい下限は0.50超%であり、さらに好ましくは0.7%であり、さらに好ましくは1.0%である。Co含有量の好ましい上限は2.5%であり、さらに好ましくは2.0%である。
上述の鋼材の化学組成はさらに、Feの一部に代えて、Cu及びNiからなる群から選択される1種以上を含有してもよい。これらの元素はいずれも任意元素であり、鋼の強度を高める。
銅(Cu)は任意元素であり、含有されなくてもよい。含有される場合、Cuは鋼の焼入れ性を高め、鋼の強度を高める。しかしながら、Cu含有量が高すぎれば、水素をトラップするようになり、耐SSC性が低下する。したがって、Cu含有量は0~0.5%である。Cu含有量の好ましい下限は0.02%であり、さらに好ましくは0.05%である。Cu含有量の好ましい上限は0.35%であり、さらに好ましくは0.25%である。
ニッケル(Ni)は任意元素であり、含有されなくてもよい。含有される場合、Niは鋼の焼入れ性を高め、鋼の強度を高める。しかしながら、Ni含有量が高すぎれば、局部的な腐食を促進させ、耐SSC性が低下する。したがって、Ni含有量は0~0.5%である。Ni含有量の好ましい下限は0.02%であり、さらに好ましくは0.05%である。Ni含有量の好ましい上限は0.35%であり、さらに好ましくは0.25%である。
チタン(Ti)は任意元素であり、含有されなくてもよい。含有される場合、Tiは窒化物を形成し、ピンニング効果により、結晶粒を微細化する。これにより、鋼の強度が高まる。しかしながら、Ti含有量が高すぎれば、Ti窒化物が粗大化して鋼の耐SSC性が低下する。したがって、Ti含有量は0~0.03%である。Ti含有量の好ましい下限は0.003%であり、さらに好ましくは0.005%である。Ti含有量の好ましい上限は0.015%であり、さらに好ましくは0.012%である。
ニオブ(Nb)は任意元素であり、含有されなくてもよい。含有される場合、Nbは、C及び/又はNと結合して炭化物、窒化物又は炭窒化物(以下、炭窒化物等という)を形成する。これらの炭窒化物等は結晶粒を微細化して鋼の強度を高める。しかしながら、Nb含有量が高すぎれば、粗大な析出物が生成して鋼の耐SSC性が低下する。したがって、Nb含有量は0~0.15%である。Nb含有量の好ましい下限は0.003%であり、さらに好ましくは0.007%である。Nb含有量の好ましい上限は0.050%であり、さらに好ましくは0.04%である。
バナジウム(V)は任意元素であり、含有されなくてもよい。含有される場合、Vは炭窒化物等を形成し、結晶粒を微細化して鋼の強度を高める。しかしながら、V含有量が高すぎれば、鋼の靭性が低下する。したがって、V含有量は0~0.5%である。V含有量の好ましい下限は0.005%であり、さらに好ましくは0.015%である。V含有量の好ましい上限は0.15%であり、さらに好ましくは0.12%である。
ボロン(B)は任意元素であり、含有されなくてもよい。含有される場合、Bは鋼に固溶して鋼の焼入れ性を高め、強度を高める。しかしながら、B含有量が高すぎれば、粗大な窒化物が生成して鋼の耐SSC性が低下する。したがって、B含有量は0~0.003%である。B含有量の好ましい下限は0.0003%であり、さらに好ましくは0.0007%である。B含有量の好ましい上限は0.0015%であり、さらに好ましくは0.0012%である。
カルシウム(Ca)は任意元素であり、含有されなくてもよい。含有される場合、Caは、鋼中のSと結合する。これにより、鋼中の硫化物が微細化して鋼の耐SSC性を高める。しかしながら、Ca含有量が高すぎれば、鋼中の酸化物が粗大化して、鋼の耐SSC性が低下する。したがって、Ca含有量は0~0.004%である。Ca含有量の好ましい下限は0.0003%であり、さらに好ましくは0.0006%である。Ca含有量の好ましい上限は0.0025%であり、さらに好ましくは0.0020%である。
マグネシウム(Mg)は任意元素であり、含有されなくてもよい。含有される場合、Mgは、鋼中の硫化物を微細化して鋼の耐SSC性を高める。しかしながら、Mg含有量が高すぎれば、鋼中の酸化物が粗大化して鋼の耐SSC性が低下する。したがって、Mg含有量は0~0.004%である。Mg含有量の好ましい下限は0.0003%であり、さらに好ましくは0.0006%である。Mg含有量の好ましい上限は0.0025%であり、さらに好ましくは0.0020%である。
ジルコニウム(Zr)は任意元素であり、含有されなくてもよい。含有される場合、Zrは、鋼中の硫化物を微細化して鋼の耐SSC性を高める。しかしながら、Zr含有量が高すぎれば、酸化物が粗大化して鋼の耐SSC性が低下する。したがって、Zr含有量は0~0.004%である。Zr含有量の好ましい下限は0.0003%であり、さらに好ましくは0.0006%である。Zr含有量の好ましい上限は0.0025%であり、さらに好ましくは0.0020%である。
希土類元素(REM)は任意元素であり、含有されなくてもよい。含有される場合、REMは、鋼中の硫化物を微細化して鋼の耐SSC性を高める。REMはさらに、鋼中のPと結合して、結晶粒界におけるPの偏析を抑制する。そのため、Pの偏析に起因した鋼の耐SSC性の低下が抑制される。しかしながら、REM含有量が高すぎれば、酸化物が粗大化して鋼の耐SSC性が低下する。したがって、REM含有量は0~0.004%である。REM含有量の好ましい下限は0.0003%であり、さらに好ましくは0.0006%である。REM含有量の好ましい上限は0.0025%であり、さらに好ましくは0.0020%である。
上記化学組成はさらに、式(1)及び式(2)を満たす。
C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α≧0.50 (1)
(3C+Mo+3Co)/(3Mn+Cr)≧1.0 (2)
有効B=B-11(N-Ti/3.4)/14 (3)
ここで、式(1)のαは、式(3)で定義される有効B(質量%)が0.0003%以上の場合は0.250であり、有効Bが0.0003%未満の場合は0である。式(1)~式(3)中の各元素記号には、対応する元素の含有量(質量%)が代入される。
F1=C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+αと定義する。F1は焼入れ性の指標である。F1が0.50以上であれば、Coを含有していても、優れた焼入れ性が得られ、ミクロ組織中の焼戻しマルテンサイトの体積率が90%以上となる。その結果、優れた耐SSC性が得られる。F1の好ましい下限は0.70である。
F2=(3C+Mo+3Co)/(3Mn+Cr)と定義する。F2は、耐SSC性の指標である。F2が1.0以上である場合、耐SSC性向上元素(C、Mo及びCo)の含有量の、Mn及びCr含有量(焼入れ性に寄与するものの、過剰な含有が耐SSC性を低下し得る元素)に対する比が大きくなる。その結果、高圧H2S環境での優れた耐SSC性が得られる。
本発明の鋼材のミクロ組織は、主として焼戻しマルテンサイトからなる。より具体的には、ミクロ組織は体積率で90%以上の焼戻しマルテンサイトからなる。ミクロ組織の残部はたとえば、ベイナイト、残留オーステナイト等である。ミクロ組織が体積率で90%以上の焼戻しマルテンサイトを含有すれば、耐SSC性が高まる。好ましくは、ミクロ組織は焼戻しマルテンサイト単相からなる。
ΔHRC=HRCmax-HRCmin
ΔHRCが2.0未満であれば、鋼材のミクロ組織中の焼戻しマルテンサイトの体積率が90%以上であるとみなす。
鋼材の形状は特に限定されない。鋼材はたとえば鋼管、鋼板である。鋼材が油井用の鋼管の場合、好ましい肉厚は9~60mmである。本発明は特に、厚肉の油井用鋼管としての使用に適する。より具体的には、本発明による鋼材が15mm以上、さらに、20mm以上の厚肉の油井用鋼管であっても、優れた強度及び耐SSC性を示す。
鋼材の降伏強度の好ましい下限は654MPaである。鋼材の降伏強度の上限は860MPaである。本明細書でいう降伏強度は、下降伏点(MPa)を意味する。
上述の鋼材の製造方法の一例として、油井用鋼管の製造方法を説明する。油井用鋼管の製造方法は、素材を準備する工程(準備工程)と、素材を熱間加工して素管を製造する工程(熱間加工工程)と、素管に対して焼入れ及び焼戻しを実施して、油井用鋼管にする工程(焼入れ工程及び焼戻し工程)とを備える。以下、各工程について詳述する。
上述の化学組成を有し、式(1)及び式(2)を満たす溶鋼を製造する。溶鋼を用いて素材を製造する。具体的には、溶鋼を用いて連続鋳造法により鋳片(スラブ、ブルーム、又は、ビレット)を製造する。溶鋼を用いて造塊法によりインゴットを製造してもよい。必要に応じて、スラブ、ブルーム又はインゴットを分塊圧延して、ビレットを製造してもよい。以上の工程により素材(スラブ、ブルーム、又は、ビレット)を製造する。
準備された素材を熱間加工して素管を製造する。始めに、ビレットを加熱炉で加熱する。加熱炉から抽出されたビレットに対して熱間加工を実施して、素管(継目無鋼管)を製造する。たとえば、熱間加工としてマンネスマン法を実施し、素管を製造する。この場合、穿孔機により丸ビレットを穿孔圧延する。穿孔圧延された丸ビレットをさらに、マンドレルミル、レデューサ、サイジングミル等により熱間圧延して素管にする。
熱間加工後の素管に対して、焼入れを実施する。好ましい焼入れ温度は850~1000℃である。
上述の焼入れ処理を実施した後、焼戻し処理を実施する。焼戻し処理により、鋼材の降伏強度を調整する。焼戻し温度の好ましい下限は650℃である。焼戻し温度の好ましい上限は730℃である。
表1に示す化学組成を有する、180kgの溶鋼を製造した。
上記の焼入れ及び焼戻し処理後の各鋼板の板厚中央から、直径6.35mm、平行部長さ35mmの丸棒引張試験片を作製した。引張試験片の軸方向は、鋼板の圧延方向と平行であった。各丸棒試験片を用いて、常温(25℃)、大気中にて引張試験を実施して、各位置における降伏強度(YS)(MPa)及び引張強度(TS)(MPa)を得た。なお、本実施例では、引張試験により得られた下降伏点を、各試験番号の降伏強度(YS)と定義した。
[ミクロ組織判定試験]
上記の焼入れ及び焼戻し処理後の各鋼板に対して、JIS Z2245(2011)に準拠したロックウェル硬さ(HRC)試験を実施した。具体的には、鋼材の表面から2.0mm深さ位置、鋼材の裏面(鋼管の場合は内面)から2.0mm深さ位置、及び、鋼材の厚さ方向中央位置の各々において、任意の3箇所のロックウェル硬さ(HRC)を求めた。9点のロックウェル硬さの最大値と最小値の差ΔHRCが2.0未満の場合、HRCminの位置でも焼戻しマルテンサイトの体積率が90%以上であるとみなし、合格と判定した。ΔHRCが2.0以上の場合、HRCminの位置で焼戻しマルテンサイトの体積率が90%未満であるとみなし、不合格と判定した。その合否判定を表2に示す。
各鋼板を用いて、NACE TM0177-96 Method Dに準拠したDCB試験を実施し、耐SSC性を評価した。具体的には、各鋼板の厚さ中央部から、図3Aに示すDCB試験片を3本ずつ採取した。鋼板からさらに、図3Bに示すクサビを作製した。クサビの厚さtは2.92mmであった。なお、図3A及び図3B中の数値は、対応する部位の寸法(単位はmm)を示す。
表2に試験結果を示す。
Claims (6)
- 質量%で、
C:0.15~0.45%、
Si:0.10~1.0%、
Mn:0.10~0.90未満%、
P:0.05%以下、
S:0.01%以下、
Al:0.01~0.1%、
N:0.010%以下、
Cr:0.1~2.5%、
Mo:0.35~3.0%、
Co:0.50~3.0%、
Cu:0~0.5%、
Ni:0~0.5%、
Ti:0~0.03%、
Nb:0~0.15%、
V:0~0.5%、
B:0~0.003%、
Ca:0~0.004%、
Mg:0~0.004%、
Zr:0~0.004%、及び、
希土類元素:0~0.004%を含有し、
残部がFe及び不純物からなり、式(1)及び(2)を満たす化学組成を有し、
ミクロ組織が体積率で90%以上の焼戻しマルテンサイトを含有することを特徴とする、鋼材。
C+Mn/6+(Cr+Mo+V)/5+(Cu+Ni)/15-Co/6+α≧0.50 (1)
(3C+Mo+3Co)/(3Mn+Cr)≧1.0 (2)
有効B=B-11(N-Ti/3.4)/14 (3)
ここで、式(1)のαは、式(3)で定義される有効B(質量%)が0.0003%以上の場合は0.250であり、前記有効Bが0.0003%未満の場合は0である。式(1)~式(3)中の各元素記号には、対応する元素の含有量(質量%)が代入される。 - 請求項1に記載の鋼材であって、
前記化学組成は、
Cu:0.02~0.5%、及び、
Ni:0.02~0.5%からなる群から選択される1種以上を含有することを特徴とする、鋼材。 - 請求項1又は請求項2に記載の鋼材であって、
前記化学組成は、
Ti:0.003~0.03%、
Nb:0.003~0.15%、及び、
V:0.005~0.5%からなる群から選択される1種又は2種以上を含有することを特徴とする、鋼材。 - 請求項1~請求項3のいずれか1項に記載の鋼材であって、
前記化学組成は、
B:0.0003~0.003%を含有することを特徴とする、鋼材。 - 請求項1~請求項4のいずれか1項に記載の鋼材であって、
前記化学組成は、
Ca:0.0003~0.004%、
Mg:0.0003~0.004%、
Zr:0.0003~0.004%、及び、
希土類元素:0.0003~0.004%からなる群から選択される1種又は2種以上を含有することを特徴とする、鋼材。 - 請求項1~請求項5のいずれか1項に記載の化学組成と、
15mm以上の肉厚とを有する、油井用鋼管。
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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WO2018043570A1 (ja) * | 2016-09-01 | 2018-03-08 | 新日鐵住金株式会社 | 鋼材及び油井用鋼管 |
WO2019198459A1 (ja) * | 2018-04-09 | 2019-10-17 | 日本製鉄株式会社 | 鋼管、及び、鋼管の製造方法 |
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WO2017200033A1 (ja) * | 2016-05-20 | 2017-11-23 | 新日鐵住金株式会社 | 継目無鋼管及びその製造方法 |
AR114712A1 (es) * | 2018-03-27 | 2020-10-07 | Nippon Steel & Sumitomo Metal Corp | Material de acero adecuado para uso en entorno agrio |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4226645A (en) * | 1979-01-08 | 1980-10-07 | Republic Steel Corp. | Steel well casing and method of production |
JPS5735622A (en) * | 1980-08-11 | 1982-02-26 | Sumitomo Metal Ind Ltd | Manufacture of high strength steel for oil well with superior delayed fracture resistance |
JP2000119798A (ja) * | 1998-10-13 | 2000-04-25 | Nippon Steel Corp | 硫化物応力割れ抵抗性に優れた高強度鋼及び油井用鋼管 |
CN101845939A (zh) * | 2009-03-25 | 2010-09-29 | 宝山钢铁股份有限公司 | 一种石油套管及其制造方法 |
Family Cites Families (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS609582B2 (ja) * | 1979-06-29 | 1985-03-11 | 新日本製鐵株式会社 | 耐硫化物腐食割れ性と耐腐食性の優れた高張力鋼 |
DE3070501D1 (en) * | 1979-06-29 | 1985-05-23 | Nippon Steel Corp | High tensile steel and process for producing the same |
JPS59177350A (ja) * | 1983-03-29 | 1984-10-08 | Nippon Steel Corp | 耐硫化物腐食割れ性の優れた鋼 |
JP3358135B2 (ja) * | 1993-02-26 | 2002-12-16 | 新日本製鐵株式会社 | 耐硫化物応力割れ抵抗性に優れた高強度鋼およびその製造方法 |
FR2823226B1 (fr) * | 2001-04-04 | 2004-02-20 | V & M France | Acier et tube en acier pour usage a haute temperature |
AU2003224591C1 (en) * | 2002-06-13 | 2009-08-13 | Uddeholms Ab | Steel and mould tool for plastic materials made of the steel |
CN100451153C (zh) * | 2003-08-19 | 2009-01-14 | 杰富意钢铁株式会社 | 耐腐蚀性优良的油井用高强度不锈钢管及其制造方法 |
JP4542361B2 (ja) * | 2004-04-05 | 2010-09-15 | 新日本製鐵株式会社 | 耐溶接部再熱割れ性に優れたフェライト系電縫ボイラ鋼管および製造法 |
JP4609138B2 (ja) * | 2005-03-24 | 2011-01-12 | 住友金属工業株式会社 | 耐硫化物応力割れ性に優れた油井管用鋼および油井用継目無鋼管の製造方法 |
CN100453685C (zh) * | 2006-07-11 | 2009-01-21 | 无锡西姆莱斯石油专用管制造有限公司 | 高Cr系不锈钢无缝油井管及其生产方法 |
CN100566922C (zh) * | 2008-11-25 | 2009-12-09 | 西安摩尔石油工程实验室 | Co2和h2s共存环境中的耐腐蚀低铬油套管的制备工艺 |
JP5728836B2 (ja) * | 2009-06-24 | 2015-06-03 | Jfeスチール株式会社 | 耐硫化物応力割れ性に優れた油井用高強度継目無鋼管の製造方法 |
MX363648B (es) * | 2012-06-20 | 2019-03-28 | Nippon Steel & Sumitomo Metal Corp | Acero para articulos tubulares de paises petroleros y metodo para la produccion de los mismos. |
JP6677310B2 (ja) * | 2016-09-01 | 2020-04-08 | 日本製鉄株式会社 | 鋼材及び油井用鋼管 |
-
2017
- 2017-02-20 EP EP17759717.6A patent/EP3425078B1/en active Active
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- 2017-02-20 CA CA3016288A patent/CA3016288A1/en not_active Abandoned
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Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4226645A (en) * | 1979-01-08 | 1980-10-07 | Republic Steel Corp. | Steel well casing and method of production |
JPS5735622A (en) * | 1980-08-11 | 1982-02-26 | Sumitomo Metal Ind Ltd | Manufacture of high strength steel for oil well with superior delayed fracture resistance |
JP2000119798A (ja) * | 1998-10-13 | 2000-04-25 | Nippon Steel Corp | 硫化物応力割れ抵抗性に優れた高強度鋼及び油井用鋼管 |
CN101845939A (zh) * | 2009-03-25 | 2010-09-29 | 宝山钢铁股份有限公司 | 一种石油套管及其制造方法 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3425078A4 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018043570A1 (ja) * | 2016-09-01 | 2018-03-08 | 新日鐵住金株式会社 | 鋼材及び油井用鋼管 |
WO2019198459A1 (ja) * | 2018-04-09 | 2019-10-17 | 日本製鉄株式会社 | 鋼管、及び、鋼管の製造方法 |
JPWO2019198459A1 (ja) * | 2018-04-09 | 2021-01-14 | 日本製鉄株式会社 | 鋼管、及び、鋼管の製造方法 |
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