WO2024046371A1 - High-strength oil casing resistant to co2 and microbial corrosion and manufacturing method therefor - Google Patents

High-strength oil casing resistant to co2 and microbial corrosion and manufacturing method therefor Download PDF

Info

Publication number
WO2024046371A1
WO2024046371A1 PCT/CN2023/115864 CN2023115864W WO2024046371A1 WO 2024046371 A1 WO2024046371 A1 WO 2024046371A1 CN 2023115864 W CN2023115864 W CN 2023115864W WO 2024046371 A1 WO2024046371 A1 WO 2024046371A1
Authority
WO
WIPO (PCT)
Prior art keywords
oil casing
oil
present
temperature
corrosion
Prior art date
Application number
PCT/CN2023/115864
Other languages
French (fr)
Chinese (zh)
Inventor
齐亚猛
周雄
张春霞
张忠铧
高展
Original Assignee
宝山钢铁股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 宝山钢铁股份有限公司 filed Critical 宝山钢铁股份有限公司
Publication of WO2024046371A1 publication Critical patent/WO2024046371A1/en

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C21D8/105—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/16—Ferrous alloys, e.g. steel alloys containing copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—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 invention relates to the field of metallurgical technology, and specifically to a high-strength oil casing resistant to CO 2 and microbial corrosion and a manufacturing method thereof.
  • An oil casing has the following chemical element composition: C: 0.15-0.25%, Si: 0.2-1.0%, Mn: 0.20-1.0%, Cr: 12.0-14.0%, Ni: 0.5-1.5%, Mo: 0.2-1.0%, N: 0.03-0.10%, the rest is Fe and unavoidable impurities, it is possible to obtain oil casing with a strength of 110ksi steel grade that is resistant to CO 2 and chloride ion corrosion at temperatures exceeding 150°C. This oil casing has excellent resistance to CO2 corrosion, but does not have resistance to SRB corrosion.
  • the publication number is CN107619994A, and the publication date is January 23, 2018.
  • the Chinese patent document titled "A seamless pipeline pipe resistant to CO 2 /H 2 S and sulfate reducing bacteria corrosion and its manufacturing method" discloses a A pipeline pipe and its manufacturing method, its chemical element composition is: C: 0.03-0.10%, Si: 0.1-0.5%, Mn: 0.10-1.5%, Cr: 1.0-4.0%, Ni: 0.1-1.5%, Cu : 0.15-2.0%, Mo: 0.05-0.4%, Ti: 0.01-0.05%, REM: 0.05-0.1%, the rest are Fe and inevitable impurity elements.
  • the line pipe obtained by this invention has excellent CO 2 -H 2 S-SRB corrosion resistance, but the strength does not meet the 110ksi-125ksi steel grade.
  • the publication number is CA02872342, and the publication date is October 31, 2014.
  • the Canadian patent document titled "High-Strength Stainless Steel Seamless Oil Casing and Manufacturing Method” discloses a wall thickness exceeding 25.4mm and a yield strength of 110ksi or above. High strength High-strength stainless steel pipe for oil well pipes with excellent strength, toughness and corrosion resistance.
  • This invention can obtain a high-strength and high-toughness oil casing with excellent resistance to 230°C CO2 and Cl- corrosion, a yield strength of more than 110ksi, and a -10°C impact toughness of more than 40J.
  • the oil casing does not have SRB corrosion resistance.
  • the present invention provides a high-strength oil casing resistant to CO 2 and microbial corrosion.
  • the invention also provides a method for manufacturing high-strength oil casing resistant to CO 2 and microbial corrosion.
  • the present invention relates to an oil casing which, in addition to containing Fe and inevitable impurities, also contains the following chemical elements in mass percentage: C: 0.06%-0.20%, Cr: 1.5 %-7.0%, Cu: 0.3%-3.5%, P ⁇ 0.050% and S ⁇ 0.010%, preferably P ⁇ 0.015% and S ⁇ 0.007%.
  • the oil casing also contains the chemical element REM in mass percentage: 0.07%-0.75%, preferably 0.10%-0.75%, preferably 0.30%-0.75%.
  • the REM contains one or both of La and Ce, and the mass percentage of La and Ce satisfies: 0.07% ⁇ La+Ce ⁇ 0.35%, preferably 0.15% ⁇ La+Ce ⁇ 0.35%.
  • the oil casing of the present invention also contains the following chemical elements in mass percentage:
  • Si 0.1%-1.0%, Mn: 0.10%-2.5%, Ni: 0.5%-3.5%, Mo: 0.1%-3.5%, Nb: 0.02%-0.15%, V: 0.01%-0.20%, Al: 0.01%-0.08%, B: 0.0010%-0.008%.
  • the oil casing meets at least one of the following:
  • Mn 0.5-2.5%, preferably 1.0-2.5%;
  • V 0.06-0.20%.
  • the oil casing of the present invention is subjected to a corrosion test according to the standard ASTM G111-97 (2013) (at 40°C, CO 2 , sulfate reducing bacteria and saprophytic bacteria coexist in an environment, and the CO 2 partial pressure is 2.0MPa, sulfuric acid
  • the average corrosion rate measured (the concentration of salt-reducing bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h) is ⁇ 0.0250mm/a, and the local corrosion rate is ⁇ 0.0450mm/a.
  • the present invention also relates to a method for manufacturing the above-mentioned oil casing, which includes the following steps:
  • step S2 Heating, insulation, perforating, continuous rolling, tension reducing or sizing the tube blank in step S1 to obtain a raw tube; in the continuous rolling step, the rolling temperature is 900-970°C;
  • step S3 Cool the waste pipe in step S2 to room temperature to obtain an oil casing; preferably, the waste pipe in step S2 is water-cooled, the temperature of the waste pipe before cooling is ⁇ 870°C, and the cooling rate is 20-60°C/s.
  • the heating temperature is 1220-1280°C
  • the heat preservation time is 1-4 hours.
  • the temperature of the perforation is 1170-1250°C.
  • the method for manufacturing oil casing of the present invention further includes:
  • step S4 Perform tempering heat treatment on the oil casing in step S3.
  • the tempering temperature is 530-630°C and the holding time is 40-60 minutes.
  • the yield strength of the oil casing of the present invention is ⁇ 758MPa, preferably ⁇ 800MPa, and the full-scale impact energy at 0°C is ⁇ 80J, preferably ⁇ 95J.
  • the microstructure of the oil casing of the present invention is tempered sorbite.
  • the oil casing according to the present invention can be obtained through composition design and optimization of the manufacturing process, that is, by controlling the addition amounts of Cr and Cu in the steel, and controlling the content of impurity elements P and S in the steel, which has the characteristics of resistance to CO 2 and sulfate.
  • TMCP microstructure control technology
  • the yield strength is ⁇ 758MPa, preferably ⁇ 800MPa
  • the full-scale impact energy at 0°C is obtained ⁇ 80J, preferably ⁇ 95J oil casing.
  • Figure 1 is a metallographic diagram of an oil casing according to Embodiment 1 of the present invention.
  • the oil casing of the present invention also contains the following chemical elements in mass percentage: C: 0.06%-0.20%, Cr: 1.5%-7.0%, Cu: 0.3%-3.5% , P ⁇ 0.050%, S ⁇ 0.010%, preferably P ⁇ 0.015% and S ⁇ 0.007%.
  • the present invention can obtain an oil casing resistant to CO 2 -SRB-TGB corrosion.
  • the oil casing also contains REM in mass percentage: 0.07%-0.75%. That is to say, the present invention can further improve the CO 2 -SRB-TGB corrosion resistance of the oil casing by adding REM to the steel.
  • REM contains one or both of La and Ce, and the content of La and Ce in mass percentage satisfies the inequality: 0.07% ⁇ La+Ce ⁇ 0.35%. That is to say, the present invention further improves the CO 2 -SRB-TGB corrosion resistance of the oil casing by using REM containing La and/or Ce and controlling the addition amounts of La and Ce.
  • the oil casing of the present invention also contains the following chemical elements in mass percentage: Si: 0.1%-1.0%, Mn: 0.10%-2.5%, Ni: 0.5%-3.5%, Mo: 0.1%-3.5% , Nb: 0.02%-0.15%, V: 0.01%-0.20%, Al: 0.01%-0.08%, B: 0.0010%-0.008%.
  • the present invention can improve the strength and toughness of the oil casing.
  • C is a necessary component to ensure the room temperature strength and hardenability of steel pipes.
  • the carbon content is less than 0.06%, the hardenability is low, the strength is difficult to ensure, and the toughness will be reduced; when the carbon content is higher than 0.20%, the steel will crack due to the influence of deformation stress during the quenching process.
  • the mass of C in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758 MPa or more, and a full-scale impact energy of ⁇ 80 J at 0°C, the mass of C in the oil casing must be The percentage is controlled at 0.06%-0.20%.
  • Si is an important deoxidizer in the steelmaking process.
  • Si can also improve high-temperature oxidation resistance and acid resistance.
  • the Si content is less than 0.1%, the deoxidation effect of the steel cannot be guaranteed.
  • the Si content exceeds 1.0%, the toughness and plasticity of the steel will be reduced.
  • the mass percentage of Si in the oil casing is controlled at 0.1%-1.0%.
  • Mn has an expanded austenite phase area and can improve the hardenability of steel. However, Mn easily segregates during solidification, affecting the toughness of steel. When the Mn content is lower than 0.10%, the hardenability of the steel will be significantly reduced; when the Mn content is higher than 2.5%, component segregation and quenching cracks are prone to occur.
  • the mass percentage of Mn in the oil casing is controlled at 0.10%-2.5%, preferably 1.0 -2.5%.
  • P is a harmful element that reduces CO2 corrosion resistance and adversely affects hot processing properties. If the content of P exceeds 0.050%, the corrosion resistance performance will not meet the requirements of CO 2 environment.
  • the mass percentage of P in the oil casing is ⁇ 0.050%, preferably ⁇ 0.015%.
  • S is a harmful element that reduces hot workability and adversely affects impact toughness.
  • the mass of S in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758 MPa or more, and a full-scale impact energy of ⁇ 80 J at 0°C, the mass of S in the oil casing must be The percentage is ⁇ 0.010%, preferably ⁇ 0.007%.
  • Cr can significantly improve the resistance to CO 2 local corrosion and average corrosion in steel. This is because the addition of Cr element can improve the passivation film on the steel surface and form Cr(OH) 3 , which increases the protection ability of corrosion products and thus improves the corrosion resistance. CO 2 corrosion properties. When the Cr content is less than 1.5%, the excellent CO2 corrosion resistance of the steel cannot be guaranteed. However, the higher the Cr, the better, because the segregation of Cr carbides at the grain boundaries can easily lead to a decrease in the corrosion resistance of the steel.
  • the mass percentage of Cr in the oil casing is controlled at 1.5%-7.0%, preferably 3.0-7.0%. More preferably, it is 3.0-5.0%.
  • Ni can significantly improve the performance of the passivation film and enhance the corrosion resistance of steel. Ni can also improve the cracking problem of steelmaking billets. The problem is to reduce the tendency of cracks to form in the TMCP process.
  • the mass of Ni in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or more, and a full-scale impact energy of ⁇ 80J at 0°C, the mass of Ni in the oil casing must be The percentage is controlled at 0.5%-3.5%, preferably 1.0-3.5%.
  • Cu is a key alloy element in the present invention and is a necessary condition to ensure resistance to microbial corrosion. This is because Cu is biotoxic to microorganisms and can improve the microbial corrosion resistance of steel. Cu is evenly dispersed in the matrix as a copper-rich phase. Under microbial-rich service conditions, the copper-rich phase in the matrix can continue to dissolve and adsorb on the steel surface in the form of Cu ions and Cu-rich phases, preventing SRB and TGB. Microorganisms adsorb and grow on the surface of steel, thus playing a sterilizing role and ensuring the long-lasting resistance to microbial corrosion of steel. However, excessive Cu will cause the precipitation of coarse copper-rich phases, affecting the impact toughness and hot workability of steel.
  • the mass of Cu in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or above, and a full-scale impact energy of ⁇ 80J at 0°C, the mass of Cu in the oil casing must be The percentage is controlled at 0.3%-3.5%, preferably 1.5%-3.5%.
  • Mo can improve the strength of steel through carbides and solid solution strengthening, and will also effectively increase the pitting corrosion resistance of steel. When the Mo content is less than 0.1%, the strengthening effect and pitting corrosion resistance are relatively weak; when the Mo content exceeds 3.5%, quenching cracks are easily generated in the TMCP process.
  • the mass percentage of Mo in the oil casing is controlled at 0.1%-3.5%, preferably 1.0 -3.5%.
  • Nb is a relatively strong strengthening element that can improve the strength of steel through precipitation strengthening.
  • the Nb precipitated phase will form more nucleation particles, thereby refining the austenite grains and improving the toughness of the steel.
  • the strengthening effect is not obvious; when the Nb content exceeds 0.15%, the precipitates are more numerous and coarse, affecting the toughness and corrosion resistance of the steel.
  • the mass percentage of Nb in the oil casing is controlled at 0.02%-0.15%.
  • V is a typical precipitation strengthening element that can improve the strength of steel.
  • V content is less than 0.01%, the strengthening effect is not obvious; when the V content exceeds 0.20%, the precipitates are more numerous and coarse, affecting the toughness and corrosion resistance of the steel.
  • the mass percentage of V in the oil casing is controlled at 0.01%-0.20%, preferably 0.06 -0.20%.
  • Al is a better deoxidizing element.
  • the mass of Al in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or above, and a full-scale impact energy of ⁇ 80J at 0°C, the mass of Al in the oil casing must be The percentage is controlled at 0.01%-0.08%.
  • B is an element that significantly improves the hardenability of steel. When the B content is less than 0.0010%, the effect of improving hardenability is not obvious; when the B content exceeds 0.008%, a BN brittle phase is easily formed.
  • the mass percentage of B in the oil casing is controlled at 0.0010%-0.008%.
  • REM can effectively improve the toughness and CO2 corrosion resistance of steel; however, too much REM content will produce more coarse inclusions, affecting the toughness and corrosion resistance of steel.
  • the quality of the REM in the oil casing in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or more, and a full-scale impact energy of ⁇ 80J at 0°C, the quality of the REM in the oil casing must be The percentage is controlled at 0.07%-0.75%, preferably 0.30-0.75%.
  • the rare earth metal REM can use one or both of La and Ce.
  • La and Ce have a poisoning effect on microorganisms such as SRB and TGB.
  • REM can also improve the CO 2 corrosion resistance of steel; however, the content of La and Ce Too much will produce more coarse inclusions, affecting the toughness of the steel.
  • La and Ce in the oil casing must be The content should satisfy: 0.07% ⁇ La+Ce ⁇ 0.35%, preferably 0.15% ⁇ La+Ce ⁇ 0.35%.
  • the oil casing of the present invention is subjected to a corrosion test according to the standard ASTM G111-97 (2013) (at 40°C, CO 2 , sulfate reducing bacteria (SRB) and saprophytic bacteria (TGB) coexist in an environment, and CO 2 minutes (The pressure is 2.0MPa, the concentration of sulfate-reducing bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h) the average corrosion rate measured is ⁇ 0.0250mm/a, and the local corrosion rate is ⁇ 0.0450mm/a.
  • ASTM G111-97 (2013) at 40°C, CO 2 , sulfate reducing bacteria (SRB) and saprophytic bacteria (TGB) coexist in an environment, and CO 2 minutes (The pressure is 2.0MPa, the concentration of sulfate-reducing bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h) the average corrosion rate measured is ⁇ 0.0250mm/
  • the present invention also relates to a method for manufacturing the above-mentioned oil casing, comprising the following steps:
  • step S2 Heating, insulation, perforating, continuous rolling, tension reducing or sizing the tube blank in step S1 to obtain a raw tube; in the continuous rolling step, the rolling temperature is 900-970°C;
  • step S3 Cool the waste pipe in step S2 to room temperature to obtain a prefabricated oil casing; preferably, water-cool the waste pipe in step S2, the temperature of the waste pipe before cooling is ⁇ 870°C, and the cooling rate is 20-60°C/s.
  • the present invention controls the rolling temperature during the rolling process as well as the temperature and cooling rate during the cooling process, and can obtain a yield strength of ⁇ 758MPa, preferably ⁇ 800MPa and a 0°C full-scale impact power of ⁇ 80J, preferably ⁇ 95J oil casing, ultimately achieving energy saving, consumption reduction, green manufacturing, and good economic benefits.
  • the TMCP manufacturing process of the present invention uses the waste heat after hot rolling to directly quench, and achieves further strengthening through the deformation-induced phase change effect, which can not only further improve the comprehensive mechanical properties of oil and casing, but also save production processes. ,reduce manufacturing cost.
  • the heating temperature is 1220-1280°C
  • the heat preservation time is 1-4 hours.
  • the heating temperature is controlled at 1220-1280°C
  • the holding time is controlled at 1-4h to fully diffuse carbon and alloy elements at the composite interface to achieve metallurgical bonding. It is also beneficial to homogenize carbon and alloy elements.
  • the perforation temperature is 1170-1250°C. This is considering that for the oil casing composed of the above chemical elements, when the piercing temperature is lower than 1170°C, the deformation resistance of the obtained oil casing will be large and it will be difficult to bite in. When the piercing temperature is higher than 1250°C °C, it will lead to the generation of thermal deformation defects.
  • the manufacturing method of the oil casing of the present invention may also include S4: performing tempering heat treatment on the oil casing in step S3.
  • the tempering temperature is 530-630°C and the holding time is 40-60 minutes.
  • the tissue refinement and strengthening effects can be further improved, and an oil casing with high strength and high toughness can be obtained.
  • the yield strength of the oil casing of the present invention is ⁇ 758MPa, preferably ⁇ 800MPa, and the full-scale impact energy at 0°C is ⁇ 80J, preferably ⁇ 95J.
  • the above composition design controlling and optimizing the content of chemical elements in the steel, oil casing with excellent comprehensive mechanical properties can be obtained.
  • step S3 Control the cooling process of the waste pipe in step S2 to room temperature to obtain the oil casing
  • step S4 Perform heat treatment on the oil casing in step S3 with a tempering time of 60 minutes to obtain the oil casing of Examples 1-5.
  • the oil casing of Comparative Example 1-4 was produced using a manufacturing process similar to that of Example 1-5. However, more than one of the chemical element compositions and/or process parameters of the oil casings of Comparative Examples 1-4 does not fall within the scope of the present invention.
  • Table 1 lists the chemical element compositions of the oil casings of Examples 1-5 and Comparative Examples 1-4.
  • Table 1 Chemical element composition of the oil casings of Examples 1-5 and Comparative Examples 1-4 (wt%, the balance is Fe and unavoidable impurities other than P and S)
  • Table 2 lists the main process parameters of the hot piercing step, rolling step, controlled cooling step and heat treatment step of Examples 1-5 and Comparative Examples 1-4.
  • Figure 1 shows the metallographic diagram of the oil casing in Embodiment 1 of the present invention. It can be seen from the figure that through the above-mentioned component design and optimization of the manufacturing process parameters, the tempered sorbite microstructure can be obtained. The tempered sorbite microstructure can be obtained. The solid structure can ensure the high strength and excellent impact performance of oil casing.
  • the oil casings of the embodiments of the present invention can be used for oil and gas field exploitation.
  • the obtained oil casings of Examples 1-5 and Comparative Examples 1-4 were sampled respectively.
  • the yield strength data is obtained by processing the oil casings of Examples 1-5 and Comparative Examples 1-4 into API arc-shaped specimens, and averaging them after testing according to API standards;
  • the impact test was conducted in accordance with GB/T 229-2020. Specifically, full-size V-shaped impact specimens with a cross-sectional size of 10mm*10mm*55mm were taken from the oil casings of Examples 1-5 and Comparative Examples 1-4. Conduct impact test at 0°C temperature, and obtain the average value after the test;
  • the corrosion test was carried out in accordance with ASTM G111-97 (2013).
  • the specific conditions are that the corrosion test is carried out at 40°C, in an environment where CO 2 , sulfate-reducing bacteria and saprophytic bacteria coexist, and the CO 2 partial pressure is 2.0MPa, and the concentration of sulfate-reducing bacteria is The concentration of saprophytic bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h.
  • the average corrosion rate was obtained; cross-sectional analysis was performed on the pitting corrosion pits of the oil casings of Examples 1-5 and the steel pipes of Comparative Examples 1-4, and the local corrosion rate was obtained after conversion.
  • oil casing in Examples 1-5 has the mass percentage of chemical elements specified by the present invention, and is processed and produced according to the manufacturing process parameters provided by the present invention, an average Oil casing with corrosion rate ⁇ 0.0250mm/a, local corrosion rate ⁇ 0.0450mm/a, yield strength ⁇ 800MPa and full-size impact energy at 0°C ⁇ 95J, that is to say, oil casing in Examples 1-5 of the present invention It has excellent resistance to CO 2 -SRB-TGB corrosion and also has good mechanical strength and toughness.
  • the oil casing in the embodiment of the present invention controls the addition amount of Cr and Cu, the content of impurity elements P and S and optimizes the alloy.
  • the proportion of elements, combined with the TMCP manufacturing process, controlling the rolling temperature, pre-cooling temperature and cooling speed, can obtain CO 2 -SRB-TGB corrosion resistance, yield strength ⁇ 800MPa and 0°C full-scale impact energy ⁇ 95J oil casing.

Landscapes

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

Abstract

Provided in the present invention are a high-strength oil casing resistant to CO2 and microbial corrosion and a manufacturing method therefor. In addition to Fe and inevitable impurities, the oil casing further comprises the following chemical elements in percentages by mass: C: 0.06-0.20%, Cr: 1.5-7.0%, Cu: 0.3-3.5%, P≤0.015, and S≤0.007. In the present invention, an oil casing having CO2-SRB-TGB corrosion resistance, a yield strength of ≥758 MPa, preferably ≥800 MPa, and a full-size impact energy at 0ºC of ≥80 J, preferably ≥95 J can be obtained by controlling the addition amounts of Cr and Cu and the contents of the impurity elements of P and S, optimizing the proportions of the chemical elements, using a TMCP production and manufacturing process in combination, and controlling the rolling temperature, the temperature before cooling, and the cooling speed.

Description

一种抗CO2和微生物腐蚀的高强度油套管及其制造方法A high-strength oil casing resistant to CO2 and microbial corrosion and its manufacturing method 技术领域Technical field
本发明涉及冶金技术领域，具体涉及一种抗CO2和微生物腐蚀的高强度油套管及其制造方法。The invention relates to the field of metallurgical technology, and specifically to a high-strength oil casing resistant to CO 2 and microbial corrosion and a manufacturing method thereof.
背景技术Background technique
在油气田生产过程中，注水作业是一种比较常用且高效的工艺，因河水、湖泊水的便捷和低成本的优点，通常采用油田附近的河水、湖泊水作为注水作业用水，但是在油气田开采过程中，水中的微生物如硫酸盐还原菌(SRB)、腐生菌(TGB)等容易附着在油套管上，直接或间接地加速金属材料的腐蚀或破坏。此外，注水作业的油气田伴生气中还含有CO2腐蚀性气体，CO2会造成油套管的局部腐蚀穿孔，且CO2与微生物的耦合作用会加速油套管的腐蚀，增加油套管破漏事故的发生率。随着油气开采不断发展，注水工艺的油气井深度的增加、地层压力的增大，对油套管钢级要求越来越高。因此，油气田行业迫切希望能获得一种具备高钢级的抗CO2和微生物腐蚀的油套管产品。In the production process of oil and gas fields, water injection is a relatively common and efficient process. Due to the convenience and low cost of river water and lake water, river water and lake water near the oil field are usually used as water for water injection operations. However, in the oil and gas field production process Microorganisms in the water, such as sulfate reducing bacteria (SRB) and saprophytic bacteria (TGB), easily adhere to the oil casing, directly or indirectly accelerating the corrosion or damage of metal materials. In addition, the associated gas in oil and gas fields during water injection operations also contains corrosive gas CO2 . CO2 will cause local corrosion and perforation of oil casings, and the coupling effect of CO2 and microorganisms will accelerate the corrosion of oil casings and increase the risk of oil casing breakage. The incidence of leakage accidents. With the continuous development of oil and gas exploitation, the depth of oil and gas wells and formation pressure in the water injection process have increased, and the requirements for the steel grade of oil and casing have become higher and higher. Therefore, the oil and gas field industry is eager to obtain an oil casing product with high steel grade that is resistant to CO 2 and microbial corrosion.
公开号为CN101289730B，公开日为2011年5月11日，名称为“110ksi高钢级、高抗CO2腐蚀油套管的制法及使用该制法制得的油套管”的中国专利文献公开了一种油套管，其化学元素组成为：C：0.15-0.25％，Si：0.2-1.0％，Mn：0.20-1.0％，Cr：12.0-14.0％，Ni：0.5-1.5％，Mo：0.2-1.0％，N：0.03-0.10％，其余为Fe和不可避免的杂质，可获得在温度超过150℃的条件下耐CO2和氯离子腐蚀的强度达到110ksi钢级的油套管。该油套管抗CO2腐蚀性能优异，但不具备抗SRB腐蚀性能。The publication number is CN101289730B, the publication date is May 11, 2011, and the Chinese patent document titled "Preparation method of 110ksi high steel grade, high CO 2 corrosion-resistant oil casing and oil casing produced using the production method" is disclosed An oil casing has the following chemical element composition: C: 0.15-0.25%, Si: 0.2-1.0%, Mn: 0.20-1.0%, Cr: 12.0-14.0%, Ni: 0.5-1.5%, Mo: 0.2-1.0%, N: 0.03-0.10%, the rest is Fe and unavoidable impurities, it is possible to obtain oil casing with a strength of 110ksi steel grade that is resistant to CO 2 and chloride ion corrosion at temperatures exceeding 150°C. This oil casing has excellent resistance to CO2 corrosion, but does not have resistance to SRB corrosion.
公开号为CN107619994A，公开日为2018年1月23日，名称为“一种抗CO2/H2S及硫酸盐还原菌腐蚀的无缝管线管及其制造方法”的中国专利文献公开了一种管线管及其制造方法，其化学元素组成为：C：0.03-0.10％，Si：0.1-0.5％，Mn：0.10-1.5％，Cr：1.0-4.0％，Ni：0.1-1.5％，Cu：0.15-2.0％，Mo：0.05-0.4％，Ti：0.01-0.05％，REM：0.05-0.1％，其余为Fe和不可避免的杂质元素。该发明获得的管线管具有优异的耐CO2-H2S-SRB腐蚀性能，但强度未满足110ksi-125ksi钢级。The publication number is CN107619994A, and the publication date is January 23, 2018. The Chinese patent document titled "A seamless pipeline pipe resistant to CO 2 /H 2 S and sulfate reducing bacteria corrosion and its manufacturing method" discloses a A pipeline pipe and its manufacturing method, its chemical element composition is: C: 0.03-0.10%, Si: 0.1-0.5%, Mn: 0.10-1.5%, Cr: 1.0-4.0%, Ni: 0.1-1.5%, Cu : 0.15-2.0%, Mo: 0.05-0.4%, Ti: 0.01-0.05%, REM: 0.05-0.1%, the rest are Fe and inevitable impurity elements. The line pipe obtained by this invention has excellent CO 2 -H 2 S-SRB corrosion resistance, but the strength does not meet the 110ksi-125ksi steel grade.
公开号为CA02872342，公开日为2014年10月31日，名称为“高强度不锈钢无缝油套管及制造方法”的加拿大专利文献公开了一种壁厚超过25.4mm、屈服强度110ksi级以上的高强 度、韧性和耐腐蚀性优异的油井管用高强度不锈钢管，其化学元素组成为：C：0.005-0.06％，Si：0.05-0.50％，Mn：0.20-1.8％，Cr：15.5-18.0％，Ni：1.5-5.0％，V：0.02-0.2％，Al：0.002-0.05％，N：0.01-0.15％，Mo：1.0-3.5％，W>3.0％，Cu<3.5％，且满足关系式(％Cr)+0.65(％Ni)+0.60(％Mo)+0.30(％W)+0.55(％Cu)-20(％C)≥19.5，(％Cr)+(％Mo)+0.50(％W)+0.30(％Si)-43.5(％C)-0.4(％Mn)-(％Ni)-0.3(％Cu)-9(％N)≥11.5。该发明可获得抗230℃CO2和Cl—腐蚀性能优异、屈服强度110ksi以上、-10℃冲击韧性40J以上的高强度高韧性油套管，但该油套管不具备抗SRB腐蚀性能。The publication number is CA02872342, and the publication date is October 31, 2014. The Canadian patent document titled "High-Strength Stainless Steel Seamless Oil Casing and Manufacturing Method" discloses a wall thickness exceeding 25.4mm and a yield strength of 110ksi or above. High strength High-strength stainless steel pipe for oil well pipes with excellent strength, toughness and corrosion resistance. Its chemical element composition is: C: 0.005-0.06%, Si: 0.05-0.50%, Mn: 0.20-1.8%, Cr: 15.5-18.0%, Ni: 1.5-5.0%, V: 0.02-0.2%, Al: 0.002-0.05%, N: 0.01-0.15%, Mo: 1.0-3.5%, W>3.0%, Cu<3.5%, and satisfy the relationship ( %Cr)+0.65(%Ni)+0.60(%Mo)+0.30(%W)+0.55(%Cu)-20(%C)≥19.5, (%Cr)+(%Mo)+0.50(%W) )+0.30(%Si)-43.5(%C)-0.4(%Mn)-(%Ni)-0.3(%Cu)-9(%N)≥11.5. This invention can obtain a high-strength and high-toughness oil casing with excellent resistance to 230°C CO2 and Cl- corrosion, a yield strength of more than 110ksi, and a -10°C impact toughness of more than 40J. However, the oil casing does not have SRB corrosion resistance.
基于专利检索发现，目前还未有抗CO2-SRB-TGB腐蚀性能的110ksi-125ksi钢级油套管专利。Based on the patent search, it was found that there is currently no patent for 110ksi-125ksi steel grade oil casing with corrosion resistance of CO 2 -SRB-TGB.
发明内容Contents of the invention
对此，本发明提供一种抗CO2和微生物腐蚀的高强度油套管。In this regard, the present invention provides a high-strength oil casing resistant to CO 2 and microbial corrosion.
本发明还提供一种抗CO2和微生物腐蚀的高强度油套管的制造方法。The invention also provides a method for manufacturing high-strength oil casing resistant to CO 2 and microbial corrosion.
为了实现上述目的，本发明涉及一种油套管，所述油套管除含有Fe和不可避免的杂质外，还以质量百分比计含有如下化学元素：C：0.06％-0.20％，Cr：1.5％-7.0％，Cu：0.3％-3.5％，P≤0.050％和S≤0.010％，优选P≤0.015％和S≤0.007％。In order to achieve the above object, the present invention relates to an oil casing which, in addition to containing Fe and inevitable impurities, also contains the following chemical elements in mass percentage: C: 0.06%-0.20%, Cr: 1.5 %-7.0%, Cu: 0.3%-3.5%, P≤0.050% and S≤0.010%, preferably P≤0.015% and S≤0.007%.
优选地，所述油套管还含有以质量百分比计的化学元素REM：0.07％-0.75％，优选0.10％-0.75％，优选0.30％-0.75％。Preferably, the oil casing also contains the chemical element REM in mass percentage: 0.07%-0.75%, preferably 0.10%-0.75%, preferably 0.30%-0.75%.
优选地，所述REM包含La和Ce中的一种或两种，所述La和Ce的质量百分比满足：0.07％≤La+Ce≤0.35％，优选0.15％≤La+Ce≤0.35％。Preferably, the REM contains one or both of La and Ce, and the mass percentage of La and Ce satisfies: 0.07%≤La+Ce≤0.35%, preferably 0.15%≤La+Ce≤0.35%.
优选地，本发明的油套管还以质量百分比计含有如下化学元素：Preferably, the oil casing of the present invention also contains the following chemical elements in mass percentage:
Si：0.1％-1.0％，Mn：0.10％-2.5％，Ni：0.5％-3.5％，Mo：0.1％-3.5％，Nb：0.02％-0.15％，V：0.01％-0.20％，Al：0.01％-0.08％，B：0.0010％-0.008％。Si: 0.1%-1.0%, Mn: 0.10%-2.5%, Ni: 0.5%-3.5%, Mo: 0.1%-3.5%, Nb: 0.02%-0.15%, V: 0.01%-0.20%, Al: 0.01%-0.08%, B: 0.0010%-0.008%.
优选地，所述油套管满足如下中的一个以上：Preferably, the oil casing meets at least one of the following:
Mn：0.5-2.5％、优选1.0-2.5％；Mn: 0.5-2.5%, preferably 1.0-2.5%;
Ni：1.0-3.5％；Ni: 1.0-3.5%;
Mo：1.0-3.5％；和Mo: 1.0-3.5%; and
V：0.06-0.20％。 V: 0.06-0.20%.
优选地，本发明的油套管根据标准ASTM G111-97(2013)(在40℃，CO2、硫酸盐还原菌和腐生菌共存环境下进行腐蚀试验，且CO2分压为2.0MPa，硫酸盐还原菌浓度为50000个/mL，腐生菌浓度20000个/mL，试验时间为300h)测得的平均腐蚀速率<0.0250mm/a，局部腐蚀速率<0.0450mm/a。Preferably, the oil casing of the present invention is subjected to a corrosion test according to the standard ASTM G111-97 (2013) (at 40°C, CO 2 , sulfate reducing bacteria and saprophytic bacteria coexist in an environment, and the CO 2 partial pressure is 2.0MPa, sulfuric acid The average corrosion rate measured (the concentration of salt-reducing bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h) is <0.0250mm/a, and the local corrosion rate is <0.0450mm/a.
本发明还涉及用于制造上述油套管的方法，包括如下步骤：The present invention also relates to a method for manufacturing the above-mentioned oil casing, which includes the following steps:
S1：对钢水进行冶炼并浇铸成铸锭，接着锻造或轧制，获得管坯；S1: Smelt molten steel and cast it into ingots, then forge or roll to obtain tube blanks;
S2：对步骤S1的管坯加热、保温、穿孔、连轧、张力减径或定径，得到荒管；所述连轧步骤中，轧制温度为900-970℃；S2: Heating, insulation, perforating, continuous rolling, tension reducing or sizing the tube blank in step S1 to obtain a raw tube; in the continuous rolling step, the rolling temperature is 900-970°C;
S3：将步骤S2的荒管冷却至室温得到油套管；优选地，对步骤S2的荒管进行水冷，冷却前荒管的温度≥870℃，冷却速度为20-60℃/s。S3: Cool the waste pipe in step S2 to room temperature to obtain an oil casing; preferably, the waste pipe in step S2 is water-cooled, the temperature of the waste pipe before cooling is ≥870°C, and the cooling rate is 20-60°C/s.
优选地，在步骤S2中，所述加热的温度为1220-1280℃，所述保温的时间为1-4h。Preferably, in step S2, the heating temperature is 1220-1280°C, and the heat preservation time is 1-4 hours.
优选地，在步骤S2中，所述穿孔的温度为1170-1250℃。Preferably, in step S2, the temperature of the perforation is 1170-1250°C.
优选地，本发明的制造油套管的方法还包括：Preferably, the method for manufacturing oil casing of the present invention further includes:
S4：对步骤S3的油套管进行回火热处理，所述回火热处理步骤中，回火温度530-630℃，保温时间40-60min。S4: Perform tempering heat treatment on the oil casing in step S3. In the tempering heat treatment step, the tempering temperature is 530-630°C and the holding time is 40-60 minutes.
优选地，本发明的油套管的屈服强度≥758MPa，优选≥800MPa，0℃全尺寸冲击功≥80J，优选≥95J。Preferably, the yield strength of the oil casing of the present invention is ≥758MPa, preferably ≥800MPa, and the full-scale impact energy at 0°C is ≥80J, preferably ≥95J.
优选地，本发明的油套管的微观组织为回火索氏体。Preferably, the microstructure of the oil casing of the present invention is tempered sorbite.
本发明的上述技术方案至少具有如下有益效果之一：The above technical solution of the present invention has at least one of the following beneficial effects:
根据本发明的油套管通过成分设计并配合优化制造工艺，亦即通过控制钢中Cr、Cu的添加量，且控制钢中杂质元素P和S的含量，可以得到具有抗CO2、硫酸盐还原菌、腐生菌(CO2-SRB-TGB)腐蚀的油套管。在此基础上还通过配合添加特定含量的其他化学元素，并结合控制轧制和冷却的微结构控制技术(TMCP)生产制造工艺，得到屈服强度≥758MPa，优选≥800MPa，0℃全尺寸冲击功≥80J，优选≥95J的油套管。The oil casing according to the present invention can be obtained through composition design and optimization of the manufacturing process, that is, by controlling the addition amounts of Cr and Cu in the steel, and controlling the content of impurity elements P and S in the steel, which has the characteristics of resistance to CO 2 and sulfate. Oil casing corroded by reducing bacteria and saprophytic bacteria (CO 2 -SRB-TGB). On this basis, by adding specific contents of other chemical elements, combined with the microstructure control technology (TMCP) manufacturing process that controls rolling and cooling, the yield strength is ≥758MPa, preferably ≥800MPa, and the full-scale impact energy at 0°C is obtained ≥80J, preferably ≥95J oil casing.
附图说明Description of drawings
图1为根据本发明实施例1的油套管的金相图。 Figure 1 is a metallographic diagram of an oil casing according to Embodiment 1 of the present invention.
具体实施方式Detailed ways
为使本发明的目的、技术方案和优点更加清楚，下面将对本发明实施例的技术方案进行清楚、完整地描述。显然，所描述的实施例是本发明的一部分实施例，而不是全部的实施例。基于所描述的本发明的实施例，本领域普通技术人员所获得的所有其他实施例，都属于本发明保护的范围。In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the scope of protection of the present invention.
除非另作定义，本发明中使用的技术术语或者科学术语应当为本发明所属领域内具有一般技能的人士所理解的通常意义。本发明中使用的“第一”、“第二”以及类似的词语并不表示任何顺序、数量或者重要性，而只是用来区分不同的组成部分。同样，“一个”或者“一”等类似词语也不表示数量限制，而是表示存在至少一个。“连接”或者“相连”等类似的词语并非限定于物理的或者机械的连接，而是可以包括电性的连接，不管是直接的还是间接的。“上”、“下”、“左”、“右”等仅用于表示相对位置关系，当被描述对象的绝对位置改变后，则该相对位置关系也相应地改变。Unless otherwise defined, technical terms or scientific terms used in the present invention shall have the usual meaning understood by a person with ordinary skill in the field to which the present invention belongs. "First", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Likewise, "a" or "one" and similar words do not indicate a quantitative limit, but rather indicate the presence of at least one. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to express relative positional relationships. When the absolute position of the described object changes, the relative positional relationship also changes accordingly.
下面具体描述根据本发明的第一方面的油套管。The oil casing according to the first aspect of the present invention is described in detail below.
本发明的油套管除含有Fe和不可避免的杂质之外，还以质量百分比计含有如下化学元素：C：0.06％-0.20％，Cr：1.5％-7.0％，Cu：0.3％-3.5％，P≤0.050％，S≤0.010％，优选P≤0.015％和S≤0.007％。In addition to Fe and inevitable impurities, the oil casing of the present invention also contains the following chemical elements in mass percentage: C: 0.06%-0.20%, Cr: 1.5%-7.0%, Cu: 0.3%-3.5% , P≤0.050%, S≤0.010%, preferably P≤0.015% and S≤0.007%.
本发明通过控制钢中Cr、Cu的添加量，且控制杂质元素P和S的含量，可以得到具有抗CO2-SRB-TGB腐蚀的油套管。By controlling the addition amounts of Cr and Cu in the steel and controlling the contents of impurity elements P and S, the present invention can obtain an oil casing resistant to CO 2 -SRB-TGB corrosion.
优选地，油套管还含有以质量百分比计的REM：0.07％-0.75％。也就是说，本发明通过在钢中加入REM，可进一步提高油套管的抗CO2-SRB-TGB腐蚀性能。Preferably, the oil casing also contains REM in mass percentage: 0.07%-0.75%. That is to say, the present invention can further improve the CO 2 -SRB-TGB corrosion resistance of the oil casing by adding REM to the steel.
优选地，REM包含La和Ce中的一种或两种，La和Ce以质量百分比计的含量满足不等式：0.07％≤La+Ce≤0.35％。也就是说，本发明通过使用含有La和/或Ce的REM，并控制La和Ce的添加量，进一步提高油套管的抗CO2-SRB-TGB腐蚀性能。Preferably, REM contains one or both of La and Ce, and the content of La and Ce in mass percentage satisfies the inequality: 0.07%≤La+Ce≤0.35%. That is to say, the present invention further improves the CO 2 -SRB-TGB corrosion resistance of the oil casing by using REM containing La and/or Ce and controlling the addition amounts of La and Ce.
优选地，本发明的油套管还以质量百分比计含有如下化学元素：Si：0.1％-1.0％，Mn：0.10％-2.5％，Ni：0.5％-3.5％，Mo：0.1％-3.5％，Nb：0.02％-0.15％，V：0.01％-0.20％，Al：0.01％-0.08％，B：0.0010％-0.008％。本发明通过进一步添加上述特定含量的化学元素，可提高油套管的强度和韧性。Preferably, the oil casing of the present invention also contains the following chemical elements in mass percentage: Si: 0.1%-1.0%, Mn: 0.10%-2.5%, Ni: 0.5%-3.5%, Mo: 0.1%-3.5% , Nb: 0.02%-0.15%, V: 0.01%-0.20%, Al: 0.01%-0.08%, B: 0.0010%-0.008%. By further adding the above-mentioned specific content of chemical elements, the present invention can improve the strength and toughness of the oil casing.
具体的，本发明的油套管中各化学元素的设计原理如下： Specifically, the design principles of each chemical element in the oil casing of the present invention are as follows:
C：C是保证钢管室温强度和淬透性所必需的成分。碳含量低于0.06％时，则淬透性较低，强度难以保证，韧性也会降低；碳含量高于0.20％时，在淬火工艺中，会使钢因变形应力的影响而产生裂纹。C: C is a necessary component to ensure the room temperature strength and hardenability of steel pipes. When the carbon content is less than 0.06%, the hardenability is low, the strength is difficult to ensure, and the toughness will be reduced; when the carbon content is higher than 0.20%, the steel will crack due to the influence of deformation stress during the quenching process.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中C的质量百分比控制在0.06％-0.20％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758 MPa or more, and a full-scale impact energy of ≥80 J at 0°C, the mass of C in the oil casing must be The percentage is controlled at 0.06%-0.20%.
Si：Si是炼钢过程中重要的脱氧剂。此外Si还可以提高高温抗氧化和耐酸性能。Si含量低于0.1％时，无法保证钢的脱氧效果，Si含量超过1.0％时，会降低钢的韧性和塑性。Si: Si is an important deoxidizer in the steelmaking process. In addition, Si can also improve high-temperature oxidation resistance and acid resistance. When the Si content is less than 0.1%, the deoxidation effect of the steel cannot be guaranteed. When the Si content exceeds 1.0%, the toughness and plasticity of the steel will be reduced.
因此，在本发明中，对于要获得屈服强度为≥758MPa，0℃全尺寸冲击功≥80J的油套管而言，油套管中Si的质量百分比控制在0.1％-1.0％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of ≥758MPa and a full-scale impact energy of ≥80J at 0°C, the mass percentage of Si in the oil casing is controlled at 0.1%-1.0%.
Mn：Mn具有扩大奥氏体相区，可提高钢的淬透性。但Mn在凝固时容易产生偏析，影响钢的韧性。当Mn含量低于0.10％时，钢淬透性会显著降低；当Mn含量高于2.5％时，易发生成分偏析、产生淬火裂纹。Mn: Mn has an expanded austenite phase area and can improve the hardenability of steel. However, Mn easily segregates during solidification, affecting the toughness of steel. When the Mn content is lower than 0.10%, the hardenability of the steel will be significantly reduced; when the Mn content is higher than 2.5%, component segregation and quenching cracks are prone to occur.
因此，在本发明中，对于要获得屈服强度为≥758MPa，0℃全尺寸冲击功≥80J的油套管而言，油套管中Mn的质量百分比控制在0.10％-2.5％，优选为1.0-2.5％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of ≥758MPa and a full-scale impact energy of ≥80J at 0°C, the mass percentage of Mn in the oil casing is controlled at 0.10%-2.5%, preferably 1.0 -2.5%.
P：P是抗CO2腐蚀性能下降的有害元素，且对热加工性能产生不利影响。若P的含量超过0.050％，则使抗腐蚀的性能无法满足CO2环境要求。P: P is a harmful element that reduces CO2 corrosion resistance and adversely affects hot processing properties. If the content of P exceeds 0.050%, the corrosion resistance performance will not meet the requirements of CO 2 environment.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能的油套管而言，油套管中P的质量百分比≤0.050％、优选≤0.015％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, the mass percentage of P in the oil casing is ≤0.050%, preferably ≤0.015%.
S：S是使得热加工性能降低同时对冲击韧性产生不良影响的有害元素。S: S is a harmful element that reduces hot workability and adversely affects impact toughness.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中S的质量百分比≤0.010％、优选≤0.007％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758 MPa or more, and a full-scale impact energy of ≥80 J at 0°C, the mass of S in the oil casing must be The percentage is ≤0.010%, preferably ≤0.007%.
Cr：Cr能够明显提高钢中抗CO2局部腐蚀和平均腐蚀能力，这是因为加入Cr元素能改善钢表面的钝化膜，并形成Cr(OH)3，增加腐蚀产物保护能力，进而提高耐CO2腐蚀性能。当Cr含量低于1.5％时，不能保证钢优异的耐CO2腐蚀性能。然而Cr不是越高越好，因为Cr的碳化物在晶界的偏析容易导致钢中抗腐蚀性能下降。Cr: Cr can significantly improve the resistance to CO 2 local corrosion and average corrosion in steel. This is because the addition of Cr element can improve the passivation film on the steel surface and form Cr(OH) 3 , which increases the protection ability of corrosion products and thus improves the corrosion resistance. CO 2 corrosion properties. When the Cr content is less than 1.5%, the excellent CO2 corrosion resistance of the steel cannot be guaranteed. However, the higher the Cr, the better, because the segregation of Cr carbides at the grain boundaries can easily lead to a decrease in the corrosion resistance of the steel.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能的油套管而言，油套管中Cr的质量百分比控制在1.5％-7.0％，优选为3.0-7.0％，更优选为3.0-5.0％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, the mass percentage of Cr in the oil casing is controlled at 1.5%-7.0%, preferably 3.0-7.0%. More preferably, it is 3.0-5.0%.
Ni：Ni可以明显改善钝化膜性能，提升钢的耐腐蚀作用。Ni还可以改善炼钢钢坯开裂问 题，减少在TMCP工艺中易于形成裂纹的现象。Ni: Ni can significantly improve the performance of the passivation film and enhance the corrosion resistance of steel. Ni can also improve the cracking problem of steelmaking billets. The problem is to reduce the tendency of cracks to form in the TMCP process.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中Ni的质量百分比控制在0.5％-3.5％，优选为1.0-3.5％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or more, and a full-scale impact energy of ≥80J at 0°C, the mass of Ni in the oil casing must be The percentage is controlled at 0.5%-3.5%, preferably 1.0-3.5%.
Cu：Cu是本发明关键性合金元素，是保证耐微生物腐蚀性能的必要条件。这是因为Cu对微生物具有生物毒性，能提升钢的耐微生物腐蚀性能。Cu以富铜相平均弥散分布在基体中，在富有微生物的服役工况环境下，基体中的富铜相可以以Cu离子和富Cu相的形式持续溶出并吸附在钢表面，阻止SRB、TGB等微生物在钢表面吸附生长，从而起到杀菌的作用，保证钢材持久的耐微生物腐蚀性能。但过量Cu会导致粗大富铜相析出，影响钢的冲击韧性和热加工性能。Cu: Cu is a key alloy element in the present invention and is a necessary condition to ensure resistance to microbial corrosion. This is because Cu is biotoxic to microorganisms and can improve the microbial corrosion resistance of steel. Cu is evenly dispersed in the matrix as a copper-rich phase. Under microbial-rich service conditions, the copper-rich phase in the matrix can continue to dissolve and adsorb on the steel surface in the form of Cu ions and Cu-rich phases, preventing SRB and TGB. Microorganisms adsorb and grow on the surface of steel, thus playing a sterilizing role and ensuring the long-lasting resistance to microbial corrosion of steel. However, excessive Cu will cause the precipitation of coarse copper-rich phases, affecting the impact toughness and hot workability of steel.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中Cu的质量百分比控制在0.3％-3.5％，优选为1.5％-3.5％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or above, and a full-scale impact energy of ≥80J at 0°C, the mass of Cu in the oil casing must be The percentage is controlled at 0.3%-3.5%, preferably 1.5%-3.5%.
Mo：Mo可通过碳化物及固溶强化来提高钢强度，并且还会有效增加钢的耐点蚀能力。当Mo含量低于0.1％时，强化作用和耐点蚀性能比较弱；当Mo含量超过3.5％时，容易在TMCP工艺中产生淬火裂纹。Mo: Mo can improve the strength of steel through carbides and solid solution strengthening, and will also effectively increase the pitting corrosion resistance of steel. When the Mo content is less than 0.1%, the strengthening effect and pitting corrosion resistance are relatively weak; when the Mo content exceeds 3.5%, quenching cracks are easily generated in the TMCP process.
因此，在本发明中，对于要获得屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中Mo的质量百分比控制在0.1％-3.5％，优选为1.0-3.5％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of 758 MPa or more and a full-scale impact energy of ≥80 J at 0°C, the mass percentage of Mo in the oil casing is controlled at 0.1%-3.5%, preferably 1.0 -3.5%.
Nb：Nb是比较强的强化元素，可通过析出强化提高钢的强度。此外，Nb析出相会形成较多形核质点，从而细化奥氏体晶粒，提高钢的韧性。当Nb含量低于0.02％时，强化效果不明显；当Nb含量超过0.15％时，析出相较多且粗大，影响钢的韧性和耐腐蚀性能。Nb: Nb is a relatively strong strengthening element that can improve the strength of steel through precipitation strengthening. In addition, the Nb precipitated phase will form more nucleation particles, thereby refining the austenite grains and improving the toughness of the steel. When the Nb content is less than 0.02%, the strengthening effect is not obvious; when the Nb content exceeds 0.15%, the precipitates are more numerous and coarse, affecting the toughness and corrosion resistance of the steel.
因此，在本发明中，对于要获得屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中Nb的质量百分比控制在0.02％-0.15％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of 758 MPa or more and a full-scale impact energy of ≥80 J at 0°C, the mass percentage of Nb in the oil casing is controlled at 0.02%-0.15%.
V：V是典型析出强化元素，可提高钢的强度。当V含量低于0.01％时，强化效果不明显；当V含量超过0.20％时，析出相较多且粗大，影响钢的韧性和耐腐蚀性能。V: V is a typical precipitation strengthening element that can improve the strength of steel. When the V content is less than 0.01%, the strengthening effect is not obvious; when the V content exceeds 0.20%, the precipitates are more numerous and coarse, affecting the toughness and corrosion resistance of the steel.
因此，在本发明中，对于要获得屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中V的质量百分比控制在0.01％-0.20％，优选为0.06-0.20％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of 758 MPa or more and a full-scale impact energy of ≥80 J at 0°C, the mass percentage of V in the oil casing is controlled at 0.01%-0.20%, preferably 0.06 -0.20%.
Al：Al是比较好的脱氧元素。 Al: Al is a better deoxidizing element.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中Al的质量百分比控制在0.01％-0.08％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or above, and a full-scale impact energy of ≥80J at 0°C, the mass of Al in the oil casing must be The percentage is controlled at 0.01%-0.08%.
B：B是显著提高钢淬透性的元素。当B含量低于0.0010％时，提高淬透性效果不明显；当B含量超过0.008％时，易于形成BN脆性相。B: B is an element that significantly improves the hardenability of steel. When the B content is less than 0.0010%, the effect of improving hardenability is not obvious; when the B content exceeds 0.008%, a BN brittle phase is easily formed.
因此，在本发明中，对于要获得屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中B的质量百分比控制在0.0010％-0.008％。Therefore, in the present invention, in order to obtain an oil casing with a yield strength of 758 MPa or more and a full-scale impact energy of ≥80 J at 0°C, the mass percentage of B in the oil casing is controlled at 0.0010%-0.008%.
REM：REM可以有效提高钢的韧性和耐CO2腐蚀性能；但REM含量过多会产生较多粗大夹杂物，影响钢的韧性和耐腐蚀性能。REM: REM can effectively improve the toughness and CO2 corrosion resistance of steel; however, too much REM content will produce more coarse inclusions, affecting the toughness and corrosion resistance of steel.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中REM的质量百分比控制在0.07％-0.75％，优选为0.30-0.75％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or more, and a full-scale impact energy of ≥80J at 0°C, the quality of the REM in the oil casing must be The percentage is controlled at 0.07%-0.75%, preferably 0.30-0.75%.
优选地，稀土金属REM可以选用La和Ce中的一种或两种，La和Ce对SRB、TGB等微生物具有毒杀作用，REM还可以提升钢的抗CO2腐蚀性能；但La和Ce含量过多会产生较多粗大夹杂物，影响钢的韧性。Preferably, the rare earth metal REM can use one or both of La and Ce. La and Ce have a poisoning effect on microorganisms such as SRB and TGB. REM can also improve the CO 2 corrosion resistance of steel; however, the content of La and Ce Too much will produce more coarse inclusions, affecting the toughness of the steel.
因此，在本发明中，对于要获得具有抗CO2-SRB-TGB腐蚀性能，且屈服强度为758MPa以上，0℃全尺寸冲击功≥80J的油套管而言，油套管中La和Ce的含量应满足：0.07％≤La+Ce≤0.35％，优选0.15％≤La+Ce≤0.35％。Therefore, in the present invention, in order to obtain an oil casing with corrosion resistance of CO 2 -SRB-TGB, a yield strength of 758MPa or more, and a full-scale impact energy of ≥80J at 0°C, La and Ce in the oil casing must be The content should satisfy: 0.07%≤La+Ce≤0.35%, preferably 0.15%≤La+Ce≤0.35%.
优选地，本发明的油套管根据标准ASTM G111-97(2013)(在40℃，CO2、硫酸盐还原菌(SRB)和腐生菌(TGB)共存环境下进行腐蚀试验，且CO2分压为2.0MPa，硫酸盐还原菌浓度为50000个/mL，腐生菌浓度20000个/mL，试验时间为300h)测得的平均腐蚀速率<0.0250mm/a，局部腐蚀速率<0.0450mm/a。本发明通过上述成分设计，得到了具有优异抗CO2-SRB-TGB腐蚀性能的油套管。Preferably, the oil casing of the present invention is subjected to a corrosion test according to the standard ASTM G111-97 (2013) (at 40°C, CO 2 , sulfate reducing bacteria (SRB) and saprophytic bacteria (TGB) coexist in an environment, and CO 2 minutes (The pressure is 2.0MPa, the concentration of sulfate-reducing bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h) the average corrosion rate measured is <0.0250mm/a, and the local corrosion rate is <0.0450mm/a. Through the above component design, the present invention obtains an oil casing with excellent CO 2 -SRB-TGB corrosion resistance.
本发明还涉及用于制造上述油套管的方法，包括以下步骤：The present invention also relates to a method for manufacturing the above-mentioned oil casing, comprising the following steps:
S1：对钢水进行冶炼并浇铸成铸锭，接着锻造或轧制，获得管坯；S1: Smelt molten steel and cast it into ingots, then forge or roll to obtain tube blanks;
S2：对步骤S1的管坯加热、保温、穿孔、连轧、张力减径或定径，得到荒管；所述连轧步骤中，轧制温度为900-970℃；S2: Heating, insulation, perforating, continuous rolling, tension reducing or sizing the tube blank in step S1 to obtain a raw tube; in the continuous rolling step, the rolling temperature is 900-970°C;
S3：将步骤S2的荒管冷却至室温，得到预制油套管；优选地，对步骤S2的荒管进行水冷，冷却前荒管的温度≥870℃，冷却速度为20-60℃/s。 S3: Cool the waste pipe in step S2 to room temperature to obtain a prefabricated oil casing; preferably, water-cool the waste pipe in step S2, the temperature of the waste pipe before cooling is ≥870°C, and the cooling rate is 20-60°C/s.
在本发明中，如果冷却速度低于20℃/s，则难以获得完全马氏体组织；如果冷却速度高于60℃/s，则容易产生淬火裂纹。本发明通过上述成分设计并结合TMCP生产制造工艺，控制轧制过程中的轧制温度以及冷却过程中的温度和冷却速度，可获得屈服强度≥758MPa、优选≥800MPa和0℃全尺寸冲击功≥80J、优选≥95J的油套管，最终实现节能降耗、绿色制造，并具有良好的经济效益。In the present invention, if the cooling rate is lower than 20°C/s, it is difficult to obtain a complete martensite structure; if the cooling rate is higher than 60°C/s, quenching cracks are likely to occur. Through the above-mentioned component design and combined with the TMCP production and manufacturing process, the present invention controls the rolling temperature during the rolling process as well as the temperature and cooling rate during the cooling process, and can obtain a yield strength of ≥758MPa, preferably ≥800MPa and a 0°C full-scale impact power of ≥ 80J, preferably ≥95J oil casing, ultimately achieving energy saving, consumption reduction, green manufacturing, and good economic benefits.
值得说明的是，本发明的TMCP生产制造工艺是利用热轧后余热直接进行淬火，通过形变诱导相变效应实现进一步强化，不仅可以进一步地提高油套管的综合力学性能，还可以节约生产工序，降低生产成本。It is worth mentioning that the TMCP manufacturing process of the present invention uses the waste heat after hot rolling to directly quench, and achieves further strengthening through the deformation-induced phase change effect, which can not only further improve the comprehensive mechanical properties of oil and casing, but also save production processes. ,reduce manufacturing cost.
更具体而言，步骤S2中，加热的温度为1220-1280℃，保温的时间为1-4h。在本发明中，对于上述的化学元素组成的油套管而言，加热温度控制在1220-1280℃，保温时间控制在1-4h可以使碳和合金元素在复合界面充分扩散，实现冶金结合，还有利于碳和合金元素均质化。More specifically, in step S2, the heating temperature is 1220-1280°C, and the heat preservation time is 1-4 hours. In the present invention, for the oil casing composed of the above chemical elements, the heating temperature is controlled at 1220-1280°C, and the holding time is controlled at 1-4h to fully diffuse carbon and alloy elements at the composite interface to achieve metallurgical bonding. It is also beneficial to homogenize carbon and alloy elements.
优选地，步骤S2中，穿孔的温度为1170-1250℃。这是考虑到，对于上述的化学元素组成的油套管而言，当穿孔温度低于1170℃时，会导致所获得的油套管的变形抗力大，咬入困难，当穿孔温度高于1250℃时，则会导致热变形缺陷的产生。Preferably, in step S2, the perforation temperature is 1170-1250°C. This is considering that for the oil casing composed of the above chemical elements, when the piercing temperature is lower than 1170°C, the deformation resistance of the obtained oil casing will be large and it will be difficult to bite in. When the piercing temperature is higher than 1250°C ℃, it will lead to the generation of thermal deformation defects.
优选地，本发明的油套管的制造方法还可以包括S4：对步骤S3的油套管进行回火热处理，回火热处理步骤中，回火温度530-630℃，保温时间40-60min。也就是说，通过回火热处理并控制回火温度为530-630℃，保温时间为40-60min，可进一步提高组织细化和强化效果，得到高强度和高韧性的油套管。Preferably, the manufacturing method of the oil casing of the present invention may also include S4: performing tempering heat treatment on the oil casing in step S3. In the tempering heat treatment step, the tempering temperature is 530-630°C and the holding time is 40-60 minutes. In other words, through tempering heat treatment and controlling the tempering temperature to 530-630°C and the holding time to 40-60 minutes, the tissue refinement and strengthening effects can be further improved, and an oil casing with high strength and high toughness can be obtained.
优选地，本发明的油套管的屈服强度≥758MPa，优选≥800MPa，0℃全尺寸冲击功≥80J，优选≥95J。也就是说，通过上述的成分设计，控制并优化钢中化学元素的含量，可以得到综合力学性能优异的油套管。Preferably, the yield strength of the oil casing of the present invention is ≥758MPa, preferably ≥800MPa, and the full-scale impact energy at 0°C is ≥80J, preferably ≥95J. In other words, through the above composition design, controlling and optimizing the content of chemical elements in the steel, oil casing with excellent comprehensive mechanical properties can be obtained.
为使本发明的目的、技术方案和优点更加清楚，下面将对本发明的实施方式作进一步地详细描述。In order to make the purpose, technical solutions and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below.
实施例1-5和比较例1-4Examples 1-5 and Comparative Examples 1-4
本发明的实施例1-5的油套管通过如下步骤制得：The oil casings of Examples 1-5 of the present invention are produced through the following steps:
S1：根据表1所示的配方，对钢水进行冶炼、浇铸、锻造，得到管坯；S1: According to the formula shown in Table 1, smelt, cast, and forge the molten steel to obtain the tube blank;
S2：将管坯加热3h，依次对管坯进行穿孔、轧制，最终通过张力减径得到荒管；S2: Heat the tube blank for 3 hours, pierce and roll the tube blank in sequence, and finally obtain the raw tube through tension reduction;
S3：对步骤S2的荒管进行控制冷却处理至室温，得到油套管； S3: Control the cooling process of the waste pipe in step S2 to room temperature to obtain the oil casing;
S4：对步骤S3的油套管进行热处理，回火时间为60min，得到实施例1-5的油套管。S4: Perform heat treatment on the oil casing in step S3 with a tempering time of 60 minutes to obtain the oil casing of Examples 1-5.
比较例1-4的油套管采用与实施例1-5类似的制造工艺制得。然而，比较例1-4的油套管的化学元素组成和/或工艺参数中的一个以上没有落入本发明范围内。The oil casing of Comparative Example 1-4 was produced using a manufacturing process similar to that of Example 1-5. However, more than one of the chemical element compositions and/or process parameters of the oil casings of Comparative Examples 1-4 does not fall within the scope of the present invention.
表1列出了实施例1-5和比较例1-4的油套管的化学元素组成。Table 1 lists the chemical element compositions of the oil casings of Examples 1-5 and Comparative Examples 1-4.
表1：实施例1-5和比较例1-4的油套管的化学元素组成(wt％，余量为Fe和P、S以外的不可避免的杂质)
Table 1: Chemical element composition of the oil casings of Examples 1-5 and Comparative Examples 1-4 (wt%, the balance is Fe and unavoidable impurities other than P and S)
表2列出了实施例1-5和比较例1-4的热穿孔步骤、轧制步骤、控制冷却步骤和热处理步骤的主要工艺参数。Table 2 lists the main process parameters of the hot piercing step, rolling step, controlled cooling step and heat treatment step of Examples 1-5 and Comparative Examples 1-4.
表2
Table 2
图1示出了本发明实施例1的油套管的金相图，从图中可以看出通过上述成分设计和制造工艺参数的优化，可以得到回火索氏体微观组织，回火索氏体组织可以保证油套管高强度和优异冲击性能。 Figure 1 shows the metallographic diagram of the oil casing in Embodiment 1 of the present invention. It can be seen from the figure that through the above-mentioned component design and optimization of the manufacturing process parameters, the tempered sorbite microstructure can be obtained. The tempered sorbite microstructure can be obtained. The solid structure can ensure the high strength and excellent impact performance of oil casing.
本发明实施例的油套管可用于油气田开采使用，为进一步验证其力学性能，分别对得到的实施例1-5和比较例1-4的油套管进行取样。The oil casings of the embodiments of the present invention can be used for oil and gas field exploitation. In order to further verify their mechanical properties, the obtained oil casings of Examples 1-5 and Comparative Examples 1-4 were sampled respectively.
屈服强度数据是分别将实施例1-5和比较例1-4的油套管加工成API弧形试样，按API标准检验后取平均数得出；The yield strength data is obtained by processing the oil casings of Examples 1-5 and Comparative Examples 1-4 into API arc-shaped specimens, and averaging them after testing according to API standards;
冲击试验按照GB/T 229-2020进行，具体为分别在实施例1-5和比较例1-4的油套管上截取截面尺寸为10mm*10mm*55mm的全尺寸V型冲击试样，在0℃温度下进行冲击试验，试验后取平均数得出；The impact test was conducted in accordance with GB/T 229-2020. Specifically, full-size V-shaped impact specimens with a cross-sectional size of 10mm*10mm*55mm were taken from the oil casings of Examples 1-5 and Comparative Examples 1-4. Conduct impact test at 0℃ temperature, and obtain the average value after the test;
腐蚀试验按照ASTM G111-97(2013)进行，具体条件为在40℃，CO2、硫酸盐还原菌和腐生菌共存环境下进行腐蚀试验，且CO2分压为2.0MPa，硫酸盐还原菌浓度为50000个/mL，腐生菌浓度20000个/mL，试验时间为300h，分别对实施例1-5和比较例1-4的油套管试验前、后的重量进行称重，经换算后得到出平均腐蚀速率；分别对实施例1-5的油套管和比较例1-4的钢管的点蚀坑进行截面分析，经换算后得到局部腐蚀速率。The corrosion test was carried out in accordance with ASTM G111-97 (2013). The specific conditions are that the corrosion test is carried out at 40°C, in an environment where CO 2 , sulfate-reducing bacteria and saprophytic bacteria coexist, and the CO 2 partial pressure is 2.0MPa, and the concentration of sulfate-reducing bacteria is The concentration of saprophytic bacteria is 50,000/mL, the concentration of saprophytic bacteria is 20,000/mL, and the test time is 300h. Weigh the weight of the oil casing of Examples 1-5 and Comparative Examples 1-4 before and after the test, and obtain after conversion. The average corrosion rate was obtained; cross-sectional analysis was performed on the pitting corrosion pits of the oil casings of Examples 1-5 and the steel pipes of Comparative Examples 1-4, and the local corrosion rate was obtained after conversion.
实施例1-5和比较例1-4的油套管的屈服强度、0℃全尺寸冲击功、平均腐蚀速率和局部腐蚀速率结果如表3所示。The yield strength, 0°C full-scale impact energy, average corrosion rate and local corrosion rate results of the oil casings of Examples 1-5 and Comparative Examples 1-4 are shown in Table 3.
表3：性能测试结果
Table 3: Performance test results
结合表1-3可以看出，由于实施例1-5中的油套管具有本发明所规定的化学元素质量百分配比，并且其按照本发明提供的制造工艺参数进行加工生产，从而获得平均腐蚀速率<0.0250mm/a、局部腐蚀速率<0.0450mm/a、屈服强度≥800MPa且0℃全尺寸冲击功≥95J的油套管，也就是说，本发明实施例1-5的油套管具有优异的抗CO2-SRB-TGB腐蚀性能，并且还具有良好的机械强度和韧性。It can be seen from Tables 1-3 that since the oil casing in Examples 1-5 has the mass percentage of chemical elements specified by the present invention, and is processed and produced according to the manufacturing process parameters provided by the present invention, an average Oil casing with corrosion rate <0.0250mm/a, local corrosion rate <0.0450mm/a, yield strength ≥800MPa and full-size impact energy at 0°C ≥95J, that is to say, oil casing in Examples 1-5 of the present invention It has excellent resistance to CO 2 -SRB-TGB corrosion and also has good mechanical strength and toughness.
本发明实施例的油套管通过控制Cr、Cu的添加量、杂质元素P和S的含量并优化合金 元素的配比，同时结合TMCP生产制造工艺，控制轧制温度和冷却前温度以及冷却速度，可以得到具有抗CO2-SRB-TGB腐蚀性能、屈服强度≥800MPa且0℃全尺寸冲击功≥95J的油套管。The oil casing in the embodiment of the present invention controls the addition amount of Cr and Cu, the content of impurity elements P and S and optimizes the alloy. The proportion of elements, combined with the TMCP manufacturing process, controlling the rolling temperature, pre-cooling temperature and cooling speed, can obtain CO 2 -SRB-TGB corrosion resistance, yield strength ≥800MPa and 0℃ full-scale impact energy ≥95J oil casing.
以上所述是本发明的优选实施方式，应当指出，对于本技术领域的普通技术人员来说，在不脱离本发明所述原理的前提下，还可以做出若干改进和修改，这些改进和修改也应视为本发明的保护范围。 The above is the preferred embodiment of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (12)

  1. 一种油套管，其中，所述油套管除含有Fe和不可避免的杂质之外，还以质量百分比计含有如下化学元素：C：0.06％-0.20％，Cr：1.5％-7.0％，Cu：0.3％-3.5％，P≤0.050％和S≤0.010％，优选P≤0.015％和S≤0.007％。An oil casing, wherein in addition to Fe and inevitable impurities, the oil casing also contains the following chemical elements in mass percentage: C: 0.06%-0.20%, Cr: 1.5%-7.0%, Cu: 0.3%-3.5%, P≤0.050% and S≤0.010%, preferably P≤0.015% and S≤0.007%.
  2. 根据权利要求1所述的油套管，其中，所述油套管还以质量百分比计含有REM：0.07％-0.75％，优选0.10％-0.75％。The oil casing according to claim 1, wherein the oil casing also contains REM in mass percentage: 0.07%-0.75%, preferably 0.10%-0.75%.
  3. 根据权利要求2所述的油套管，其中，所述REM包含La和Ce中的一种或两种，并且La和Ce以质量百分比计的含量满足如下不等式：0.07％≤La+Ce≤0.35％，优选0.15％≤La+Ce≤0.35％。The oil casing according to claim 2, wherein the REM contains one or both of La and Ce, and the contents of La and Ce in mass percentage satisfy the following inequality: 0.07%≤La+Ce≤0.35 %, preferably 0.15%≤La+Ce≤0.35%.
  4. 根据权利要求1所述的油套管，其中，Cr含量为3.0-7.0％，优选3.0-5.0％；和/或Cu含量为1.5％-3.5％。The oil casing according to claim 1, wherein the Cr content is 3.0-7.0%, preferably 3.0-5.0%; and/or the Cu content is 1.5%-3.5%.
  5. 根据权利要求1所述的油套管，其中，所述油套管还含有以质量百分比计的如下化学元素：Si：0.1％-1.0％，Mn：0.10％-2.5％，Ni：0.5％-3.5％，Mo：0.1％-3.5％，Nb：0.02％-0.15％，V：0.01％-0.20％，Al：0.01％-0.08％，B：0.0010％-0.008％。The oil casing according to claim 1, wherein the oil casing also contains the following chemical elements in mass percentage: Si: 0.1%-1.0%, Mn: 0.10%-2.5%, Ni: 0.5%- 3.5%, Mo: 0.1%-3.5%, Nb: 0.02%-0.15%, V: 0.01%-0.20%, Al: 0.01%-0.08%, B: 0.0010%-0.008%.
  6. 根据权利要求5所述的油套管，其中，所述油套管满足如下中的一个以上：The oil casing according to claim 5, wherein the oil casing satisfies more than one of the following:
    Mn：0.5-2.5％；Mn: 0.5-2.5%;
    Ni：1.0-3.5％；Ni: 1.0-3.5%;
    Mo：1.0-3.5％；和Mo: 1.0-3.5%; and
    V：0.06-0.20％。V: 0.06-0.20%.
  7. 根据权利要求1所述的油套管，其中，所述油套管根据标准ASTM G111-97(2013)测得的平均腐蚀速率<0.0250mm/a，局部腐蚀速率<0.0450mm/a。The oil casing according to claim 1, wherein the average corrosion rate of the oil casing measured according to standard ASTM G111-97 (2013) is <0.0250mm/a, and the local corrosion rate is <0.0450mm/a.
  8. 根据权利要求1所述的油套管，其中，所述油套管的屈服强度≥758MPa、优选≥800MPa，0℃全尺寸冲击功≥80J、优选≥95J；和/或，所述油套管的微观组织为回火索氏体。The oil casing according to claim 1, wherein the yield strength of the oil casing is ≥758MPa, preferably ≥800MPa, and the full-scale impact energy at 0°C is ≥80J, preferably ≥95J; and/or, the oil casing The microstructure is tempered sorbite.
  9. 一种制造权利要求1至8中任一项所述的油套管的方法，其中，所述方法包括如下步骤：A method of manufacturing the oil casing according to any one of claims 1 to 8, wherein the method includes the following steps:
    S1：对钢水进行冶炼和浇铸，锻造或轧制，得到管坯；S1: Smelting and casting, forging or rolling molten steel to obtain tube blanks;
    S2：对步骤S1的管坯加热、保温、穿孔、连轧、张力减径或定径，得到荒管；其中，在连轧步骤中，轧制温度为900-970℃；S2: Heating, insulation, perforating, continuous rolling, tension reducing or sizing the tube blank in step S1 to obtain a raw tube; wherein, in the continuous rolling step, the rolling temperature is 900-970°C;
    S3：将步骤S2的荒管冷却至室温，得到油套管；优选地，对步骤S2的荒管进行水冷，冷却前荒管的温度≥870℃，冷却速度为20-60℃/s。S3: Cool the waste pipe in step S2 to room temperature to obtain an oil casing; preferably, the waste pipe in step S2 is water-cooled, the temperature of the waste pipe before cooling is ≥870°C, and the cooling rate is 20-60°C/s.
  10. 根据权利要求9所述的方法，其中，在步骤S2中，所述加热的温度为1220-1280℃， 所述保温的时间为1-4h。The method according to claim 9, wherein in step S2, the heating temperature is 1220-1280°C, The heat preservation time is 1-4h.
  11. 根据权利要求9所述的方法，其中，在步骤S2中，所述穿孔的温度为1170-1250℃。The method according to claim 9, wherein in step S2, the temperature of the perforation is 1170-1250°C.
  12. 根据权利要求9所述的方法，其中，所述方法还包括如下步骤：The method according to claim 9, wherein the method further includes the following steps:
    S4：对步骤S3的油套管进行回火热处理，其中，回火温度530-630℃，保温时间40-60min。 S4: Perform tempering heat treatment on the oil casing in step S3, wherein the tempering temperature is 530-630°C and the holding time is 40-60 minutes.
PCT/CN2023/115864 2022-08-30 2023-08-30 High-strength oil casing resistant to co2 and microbial corrosion and manufacturing method therefor WO2024046371A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN202211060207.9 2022-08-30
CN202211060207.9A CN117660848A (en) 2022-08-30 2022-08-30 CO-resistant 2 High-strength oil casing pipe with microbial corrosion and manufacturing method thereof

Publications (1)

Publication Number Publication Date
WO2024046371A1 true WO2024046371A1 (en) 2024-03-07

Family

ID=90066843

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2023/115864 WO2024046371A1 (en) 2022-08-30 2023-08-30 High-strength oil casing resistant to co2 and microbial corrosion and manufacturing method therefor

Country Status (2)

Country Link
CN (1) CN117660848A (en)
WO (1) WO2024046371A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101082112A (en) * 2006-05-30 2007-12-05 宝山钢铁股份有限公司 110Ksi grade CO2 H2S rust-proof oil well-pipe and manufacturing method
CN103233180A (en) * 2013-05-17 2013-08-07 宝山钢铁股份有限公司 High-strength dual-phase stainless steel tube and preparation method thereof
JP2018031027A (en) * 2016-08-22 2018-03-01 新日鐵住金株式会社 High strength seamless oil well tube and manufacturing method therefor
US20180291475A1 (en) * 2015-06-18 2018-10-11 Baoshan Iron & Steel Co., Ltd. Ultra-high strength and ultra-high toughness casing steel, oil casing, and manufacturing method thereof
CN113802070A (en) * 2020-06-16 2021-12-17 宝山钢铁股份有限公司 Oil casing pipe resistant to corrosion of carbon dioxide and sulfate reducing bacteria and manufacturing method thereof

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101082112A (en) * 2006-05-30 2007-12-05 宝山钢铁股份有限公司 110Ksi grade CO2 H2S rust-proof oil well-pipe and manufacturing method
CN103233180A (en) * 2013-05-17 2013-08-07 宝山钢铁股份有限公司 High-strength dual-phase stainless steel tube and preparation method thereof
US20180291475A1 (en) * 2015-06-18 2018-10-11 Baoshan Iron & Steel Co., Ltd. Ultra-high strength and ultra-high toughness casing steel, oil casing, and manufacturing method thereof
JP2018031027A (en) * 2016-08-22 2018-03-01 新日鐵住金株式会社 High strength seamless oil well tube and manufacturing method therefor
CN113802070A (en) * 2020-06-16 2021-12-17 宝山钢铁股份有限公司 Oil casing pipe resistant to corrosion of carbon dioxide and sulfate reducing bacteria and manufacturing method thereof

Also Published As

Publication number Publication date
CN117660848A (en) 2024-03-08

Similar Documents

Publication Publication Date Title
WO2017162160A1 (en) Steel for hydrogen sulfide stress corrosion cracking resistant martensitic stainless steel oil casing pipe, and oil casing pipe and production method therefor
CN100500917C (en) Sulfur erosion resisting steel smelting method
WO2006109664A1 (en) Ferritic heat-resistant steel
JP5499575B2 (en) Martensitic stainless steel seamless pipe for oil well pipe and method for producing the same
JPH10280037A (en) Production of high strength and high corrosion-resistant seamless seamless steel pipe
CN108220823B (en) High temperature resistant stainless steel
JP2009030153A (en) Process for production of high alloy steel pipe
WO2021218932A1 (en) High strength, high-temperature corrosion resistant martensitic stainless steel and manufacturing method therefor
CN115612929A (en) Petroleum casing pipe for heavy oil thermal production well and preparation method thereof
CN115505849A (en) Oil casing pipe and preparation method and application thereof
JP2017166060A (en) Material for high-strength oil well steel tube and method of manufacturing high-strength oil well steel tube using the material
CN116904859B (en) Steel pipe for petroleum well and preparation method thereof
CN113106356A (en) High-strength martensite precipitation hardening stainless steel and preparation method thereof
CN104357733B (en) A kind of production method of stainless screw-thread steel
WO2024046371A1 (en) High-strength oil casing resistant to co2 and microbial corrosion and manufacturing method therefor
CN114277310B (en) anti-H 2 S-corrosion oil casing and manufacturing method thereof
CN103820714B (en) The anti-CO of high-intensity high-tenacity2the preparation method of corrosion sleeve pipe
CN106555095B (en) For containing H2The corrosion resistant alloy of S oil gas engineerings, oil well pipe and its manufacture method containing the alloy
JP2003183781A (en) Martensitic stainless steel
WO2023231981A1 (en) High-strength petroleum pipe casing and manufacturing method therefor
CN115491606B (en) CO-resistant low Cr content 2 Corrosion oil casing and preparation method thereof
CN111961973B (en) Low-alloy high-strength sulfur-resistant oil sleeve material and preparation method thereof
CN113201697B (en) High-temperature concentrated sulfuric acid corrosion resistant austenitic stainless steel with excellent hot-working performance and hot-piercing method thereof
CN108754322A (en) High-strength resistance welding sleeve and manufacturing method thereof
JP6747628B1 (en) Duplex stainless steel, seamless steel pipe, and method for producing duplex stainless steel

Legal Events

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

Ref document number: 23859400

Country of ref document: EP

Kind code of ref document: A1