US20060266448A1 - Seamless steel pipe for oil wells excellent in sulfide stress cracking resistance and method for producing the same - Google Patents

Seamless steel pipe for oil wells excellent in sulfide stress cracking resistance and method for producing the same Download PDF

Info

Publication number
US20060266448A1
US20060266448A1 US11/494,608 US49460806A US2006266448A1 US 20060266448 A1 US20060266448 A1 US 20060266448A1 US 49460806 A US49460806 A US 49460806A US 2006266448 A1 US2006266448 A1 US 2006266448A1
Authority
US
United States
Prior art keywords
steel pipe
less
seamless steel
oil wells
temperature
Prior art date
Legal status (The legal status 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 status listed.)
Abandoned
Application number
US11/494,608
Other languages
English (en)
Inventor
Yuji Arai
Tomohiko Omura
Keiichi Nakamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Individual
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 Individual filed Critical Individual
Assigned to SUMITOMO METAL INDUSTRIES, LTD. reassignment SUMITOMO METAL INDUSTRIES, LTD. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: NAKAMURA, KEIICHI, OMURA, TOMOHIKO, ARAI, YUJI
Publication of US20060266448A1 publication Critical patent/US20060266448A1/en
Priority to US13/212,400 priority Critical patent/US9017494B2/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
    • C21D8/105—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • 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
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
    • C21D9/085—Cooling or quenching
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/008—Martensite

Definitions

  • the present invention relates to a high strength seamless steel pipe which is excellent in sulfide stress cracking resistance and a method for producing the same. More specifically, the present invention relates to a seamless steel pipe for oil wells having a high yield ratio and also excellent sulfide stress cracking resistance, which is produced by the method of quenching and tempering for a specified component-based steel.
  • An oil well in the present specification includes “a gas well”, and so, the meaning of “for oil wells” is “for oil and/or gas wells”.
  • a seamless steel pipe which is more reliable than a welded pipe, is frequently used in a sever oil well environment or high-temperature environment, and the enhancement of strength, improvement in toughness and improvement in sour resistance are therefore consistently required.
  • the enhancement in strength of the steel pipe is needed more than ever before because a high-depth well will become the mainstream, and a seamless steel pipe for oil wells also having stress corrosion cracking resistance is increasingly required because the pipe is used in a severe corrosive environment.
  • the hardness, namely the dislocation density, of steel product is raised as the strength is enhanced, and the amount of hydrogen to be penetrated into the steel product increases to make the steel product fragile to stress because of the high dislocation density. Accordingly, the sulfide stress cracking resistance is generally deteriorated against the enhancement in strength of the steel product used in a hydrogen sulfide-rich environment. Particularly, when a member having a desired yield strength is produced by use of a steel product with a low ratio of “yield strength/tensile strength” (hereinafter referred to as yield ratio), the tensile strength and hardness are apt to increase, and the sulfide stress cracking resistance is remarkably deteriorated. Therefore, when the strength of the steel product is raised, it is important to increase the yield ratio for keeping the hardness low.
  • the steel product into a uniform tempered martensitic microstructure for increasing the yield ratio of the steel, that alone is insufficient.
  • refinement of prior-austenite grains is given.
  • the refinement of austenite grains needs quenching in an off-line heat treatment, which deteriorates the production efficiency and increases the energy used. Therefore, this method is disadvantageous in these days where rationalization of cost, improvement in production efficiency and energy saving are indispensable to manufacturers.
  • Patent Document 1 Japanese Laid-Open Patent Publication No. 2001-73086,
  • Patent Document 2 Japanese Laid-Open Patent Publication No. 2000-17389,
  • Patent Document 3 Japanese Laid-Open Patent Publication No. 9-111343.
  • the present invention has an object to provide a high strength seamless steel pipe for oil wells having a high yield ratio and an excellent sulfide stress cracking resistance, which can be produced by an efficient means capable of realizing an energy saving.
  • the gists of the present invention are a seamless steel pipe for oil wells described in the following (1), and a method for producing a seamless steel pipe for oil wells described in the following (2).
  • the percentage for a component content means % based on mass in the following descriptions.
  • a seamless steel pipe for oil wells which comprises C: 0.1 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.0%, Cr: 0.05 to 1.5%, Mo: 0.05 to 1.0%, Al: 0.1% or less, Ti: 0.002 to 0.05%, B: 0.0003 to 0.005%, further, one or more elements selected from one or both of the following first group and second group as occasion demands, with a value of A determined by the following equation (1) of 0.43 or more, with the balance being Fe and impurities, and in the impurities P: 0.025% or less, S: 0.010% or less and N: 0.007% or less.
  • V 0.03 to 0.2% and Nb: 0.002 to 0.04%
  • the tensile strength is not more than 931 MPa (135 ksi).
  • a method for producing a seamless steel pipe for oil wells which comprises the steps of making a pipe by hot-piercing a steel billet having a chemical composition described in the above (1) and a value of A determined by the above equation (1) of 0.43 or more followed by elongating and rolling, and finally rolling at a final rolling temperature adjusted to 800 to 1100 degrees centigrade, assistantly heating the resulting steel pipe in a temperature range from the Ar 3 transformation point to 1000 degrees centigrade in-line, and then quenching it from a temperature of the Ar 3 transformation point or higher followed by tempering at a temperature lower than the Ac 1 transformation point.
  • the temperature of the assist heating of the steel pipe in-line is between the AC 3 transformation point and 1000 degrees centigrade.
  • FIG. 1 is a graphic representation of the influence of the content of C on the relationship between yield strength (YS) and yield ratio (YR) in a quenched and tempered steel plate.
  • the present invention has been accomplished on the basis of the following findings.
  • the yield ratio of a steel product having a quenched and tempered microstructure is most significantly influenced by the content of C.
  • the yield ratio generally increases when the C content is reduced.
  • a uniform quenched microstructure cannot be obtained since the hardenability is deteriorated, and the yield ratio cannot be sufficiently raised. Therefore, it is important for the hardenability deteriorated by reducing the C content to be improved by adding Mn, Cr and Mo.
  • the A-value of the above-mentioned equation (1) is set to 0.43 or more, a uniform quenched microstructure can be obtained in a general steel pipe quenching facility.
  • the present inventors confirmed that when the A-value of the equation (1) is 0.43 or more, the hardness in a position 10 mm from a quenched end (hereinafter referred to as “Jominy end”) in a Jominy test exceeds the hardness corresponding to a martensite ratio of 90% and satisfactory hardenability can be ensured.
  • the A-value is preferably set to 0.45 or more, and more preferably 0.47 or more.
  • the present inventors further examined the influence of alloy elements on the yield ratio and sulfide stress cracking resistance of a steel product having a quenched and tempered microstructure.
  • the examination results are as follows:
  • Each of steels having chemical components shown in Table 1 was melted by use of a 150 kg vacuum melting furnace.
  • the obtained steel ingot was hot forged to form a block with 50 mm thickness, 80 mm width and 160 mm length.
  • a Jominy test piece was taken from the remaining ingot austenitized at 1100 degrees centigrade, and submitted to a Jominy test to examine the hardenability of each steel.
  • the prior-austenite grain size of each steel A to G of Table 1 was about No. 5 and relatively coarse.
  • the Rockwell C hardness in the position 10 mm from the Jominy end in the Jominy test (JHRC 10 ) of each steel A to G and the Rockwell C hardness predicted value at 90%-martensite ratio corresponding to the C content of each steel A to G are shown in Table 1.
  • the position 10 mm from the Jominy end in the Jominy test corresponds to a cooling rate of 20 degrees centigrade/second.
  • the predicted value of the Rockwell C hardness at 90%-martensite ratio based on the content C is given by “58C%+27” as shown in the following Non-Patent Document 1.
  • Non-Patent Document 1 “Relationship between hardenability and percentage martensite in some low alloy steels” by J. M. Hodge and M. A. Orehoski, Trans. AIME, 167, 1946, pp. 627-642.
  • JHRC 10 exceeds the Rockwell C hardness corresponding to 90%-martensite ratio, and satisfactory hardenability can be ensured.
  • the steel F with an A-value smaller than 0.43 of the equation (1) and the steel G containing no B (boron) are short of hardenability, since JHRC 10 is below the Rockwell C hardness corresponding to the 90%-martensite ratio.
  • each block was subjected to a heating treatment of soaking at 1250 degrees centigrade for 2 hours, immediately carried to a hot rolling machine, and hot-rolled to a thickness of 16 mm at a finish rolling temperature of 950 degrees centigrade or higher.
  • Each hot-rolled material was then carried to a heating furnace before the surface temperature becomes lower than the Ar 3 transformation point, allowed to stand therein at 950 degrees centigrade for 10 minutes, and then inserted and water-quenched in an agitating water tank.
  • Each water-quenched plate was divided to a proper length, and a tempering treatment of soaking for 30 minutes was carried out at various temperatures to obtain quenched and tempered plates. Round bar tensile test pieces were cut off from the longitudinal direction of the thus-obtained hot-rolled and heat-treated plates, and a tensile test was carried out.
  • FIG. 1 is a graphic representation of the relationship between yield strength (YS) and yield ratio (YR, the unit is represented by %) of plates changed in strength by variously changing the tempering temperature of the steels A to E.
  • the concrete data of tempering temperature and tensile properties are shown in Table 2.
  • C is an element effective for inexpensively enhancing the strength of steel.
  • the C content of less than 0.1%, a low-temperature tempering must be performed to obtain a desired strength, which causes a deterioration in sulfide stress cracking resistance, or the necessity of addition of a large amount of expensive elements to ensure the hardenability.
  • the C content exceed 0.20%, the yield ratio is reduced, and when a desired yield strength is obtained, a rise of hardness is caused to deteriorate the sulfide stress cracking resistance.
  • the C content is set to 0.1 to 0.20%.
  • the preferable range of the C content is 0.12 to 0.18%, and the more preferable range is 0.14 to 0.18%.
  • Si is an element, which enhances the hardenability of steel to improve the strength in addition to deoxidation effect, and a content of 0.05% or more is required. However, when the Si content exceeds 1.0%, the sulfide stress cracking resistance is deteriorated. Accordingly, the proper content of Si is 0.05 to 1.0%. The preferable range of the Si content is 0.1 to 0.6%.
  • Mn is an element, which enhances the hardenability of steel to improve the strength in addition to deoxidation effect, and a content of 0.05% or more is required. However, when the Mn content exceeds 1.0%, the sulfide stress cracking resistance is deteriorated. Accordingly, the content of Mn is set to 0.05 to 1.0%
  • P is an impurity of steel, which causes a deterioration in toughness resulted from grain boundary segregation. Particularly when the P content exceeds 0.025%, the sulfide stress cracking resistance is remarkably deteriorated. Accordingly, it is necessary to control the content of P to 0.025% or less.
  • the P content is preferably set to 0.020% or less and, more preferably, to 0.015% or less.
  • S is also an impurity of steel, and when the S content exceeds 0.010%, the sulfide stress cracking resistance is seriously deteriorated. Accordingly, the content of S is set to 0.010% or less.
  • the S content is preferably 0.005% or less.
  • Cr is an element effective for enhancing the hardenability of steel, and a content of 0.05% or more is required in order to exhibit this effect.
  • the content of Cr is set to 0.05 to 1.5%.
  • the preferable range of the Cr content is 0.2 to 1.0%, and the more preferable range is 0.4 to 0.8%.
  • Mo is an element effective for enhancing the hardenability of steel to ensure a high strength and for enhancing the sulfide stress cracking resistance. In order to obtain these effects, it is necessary to control the content of Mo to 0.05% or more. However, when the Mo content exceeds 1.0%, coarse carbides are formed in the prior-austenite grain boundaries to deteriorate the sulfide stress cracking resistance. Therefore, the content of Mo is set to 0.05 to 1.0%. The preferable range of the Mo content is 0.1 to 0.8%.
  • Al is an element having a deoxidation effect and effective for enhancing the toughness and workability of steel.
  • the content of Al is set to 0.10% or less.
  • the lower limit of the Al content is not particularly set because the content may be in an impurity level, the Al content is preferably set to 0.005% or more.
  • the preferable range of the Al content is 0.005 to 0.05%.
  • the Al content referred herein means the content of acid-soluble Al (what we called the “sol.Al”).
  • the B content is preferably set to 0.0003% or more in order to obtain the effect more remarkably.
  • the content of B is set to 0.0003 to 0.005%.
  • the preferable range of the B content is 0.0003 to 0.003%.
  • Ti fixes N in steel as a nitride and makes B present in a dissolved state in the matrix at the time of quenching to make it exhibit the hardenability improving effect.
  • the content of Ti is preferably set to 0.002% or more.
  • the content of Ti is set to 0.002 to 0.05%.
  • the preferable range of Ti content is 0.005 to 0.025%.
  • N is unavoidably present in steel, and binds to Al, Ti or Nb to form a nitride.
  • the presence of a large amount of N not only leads to the coarsening of AlN or TiN but also remarkably deteriorates the hardenability by also forming a nitride with B.
  • the content of N as an impurity element is set to 0.007% or less.
  • the preferable range of N is less than 0.005%.
  • the A-value is defined by the following equation (1) as described above, wherein C, Mn, Cr, and Mo in the equation (1) mean the percentage of the mass of the respective elements.
  • A C+ ( Mn/ 6)+( Cr/ 5)+( Mo/ 3) (1).
  • the present invention is intended to raise the yield ratio by limiting C to improve the sulfide stress cracking resistance. Accordingly, if the contents of Mn, Cr, and Mo are not adjusted according to the adjustment of the C content, the hardenability is impaired to rather deteriorate the sulfide stress cracking resistance. Therefore, in order to ensure the hardenability, the contents of C, Mn, Cr and Mo must be set so that the said A-value of the equation (1) is 0.43 or more.
  • the said A-value is preferably set to 0.45 or more, and more preferably to 0.47 or more.
  • the first group consists of V and Nb.
  • V precipitates as a fine carbide at the time of tempering, and so it has an effect to enhance the strength. Although such effect is exhibited by including 0.03% or more of V, the toughness is deteriorated with the content exceeding 0.2%. Accordingly, the content of added V is preferably set to 0.03 to 0.2%. The more preferable range of the V content is 0.05 to 0.15%.
  • Nb forms a carbonitride in a high temperature range to prevent the coarsening of grains to effectively improve the sulfide stress cracking resistance.
  • the content of Nb is 0.002% or more, this effect can be exhibited.
  • the content of Nb exceeds 0.04%, the carbonitride is excessively coarsened to rather deteriorate the sulfide stress cracking resistance.
  • the content of added Nb is preferably set to 0.002 to 0.04%.
  • the more preferable range of the Nb content is 0002 to 0.02%.
  • the second group consists of Ca, Mg and REM. These elements are not necessarily added. However, since they react with S in steel when added, to form sulfides to thereby improve the form of an inclusion, the sulfide stress cracking resistance of the steel can be improved as an effect. This effect can be obtained, when one or two or more selected from the group of Ca, Mg and REM (rare earth elements, namely Ce, Ra, Y and so on) is added. When the content of each element is less than 0.0003%, the effect cannot be obtained. When the content of every element exceeds 0.005%, the amount of inclusions in steel is increased, and the cleanliness of the steel is deteriorated to reduce the sulfide stress cracking resistance. Accordingly, the content of added each element is preferably set to 0.0003 to 0.005%. In the present invention, the content of REM means the sum of the contents of rare earth elements.
  • the seamless steel pipe for oil wells comprising the chemical compositions described above retains the good sulfide stress cracking resistance if the tensile strength is not more than 931 MPa. Therefore the tensile strength of the seamless steel pipe for oil well is preferably not more than 931 MPa (135 ksi). More preferably the upper limit of the tensile strength is 897 MPa (130 ksi).
  • the seamless steel pipe for oil wells of the present invention is excellent in sulfide stress cracking resistance with a high yield ratio even if it has a relatively coarse microstructure such that the microstructure is mainly composed of tempered martensite with an prior-austenite grain of No. 7 or less by a grain size number regulated in JIS G 0551 (1998). Accordingly, when a steel ingot having the above-mentioned chemical composition is used as a material, the freedom of selection for the method for producing a steel pipe can be increased.
  • the said seamless steel pipe can be produced by supplying a steel pipe formed by piercing and elongating by the Mannesmann-mandrel mill tube-making method to a heat treatment facility provided in the latter stage of a finish rolling machine while keeping it at a temperature of the Ar 3 transformation point or higher to quench it followed by tempering at 600 to 750 degrees centigrade. Even if an energy-saving type in-line tube making and heat treatment process such as the above-mentioned process is selected, a steel pipe with a high yield ratio can be produced, and a seamless steel pipe for oil wells having a desired high strength and high sulfide stress cracking resistance can be obtained.
  • the said seamless steel pipe can be also produced by cooling a hot-finish formed steel pipe once down to room temperature, reheating it in a quenching furnace to soak in a temperature range of 900 to 1000 degrees centigrade followed by quenching in water, and then tempering at 600 to 750 degrees centigrade. If an off-line tube making and heat treatment process such as the above-mentioned process is selected, a steel pipe having a higher yield ratio can be produced by the refinement effect of prior-austenite grain, and a seamless steel pipe for oil wells with higher strength and higher sulfide stress cracking resistance can be obtained.
  • the method for producing a seamless steel pipe for oil wells of the present invention is characterized in the final rolling temperature of elongating and rolling, and the heat treatment after the end of rolling. Each will be described below.
  • This temperature is set to 800 to 1100 degrees centigrade.
  • the deformation resistance of the steel pipe is excessively increased to cause a problem of tool abrasion.
  • the grains are excessively coarsened to deteriorate the sulfide stress cracking resistance.
  • the piercing process before the elongating and rolling may be carried out by a general method, such as Mannesmann piercing method.
  • the elongated and rolled steel pipe is charged in line, namely in a assistant heating furnace provided within a series of steel pipe production lines, and assistantly heated in a temperature range from the Ar 3 transformation point to 1000 degrees centigrade.
  • assistant heating is to eliminate the dispersion in the longitudinal temperature of the steel pipe to make the microstructure uniform.
  • the time of the assistant heating is set to a time necessary for making the temperature of the whole thickness of the pipe to a uniform temperature, that is about 5 to 10 minutes.
  • the assistant heating process may be omitted when the final rolling temperature of elongating and rolling is within a temperature range from the Ar 3 transformation point to 1000 degrees centigrade, the assistant heating is desirably carried out in order to minimize the longitudinal and thickness-directional dispersion in temperature of the pipe.
  • the temperature of the assist heating of a steel pipe in-line is between the Ac 3 transformation point and 1000 degrees centigrade. Therefore, the temperature of the assist heating of a steel pipe in-line is preferably between the Ac 3 transformation point and 1000 degrees centigrade.
  • the steel pipe laid in a temperature range from the Ar 3 transformation point to 1000 degrees centigrade through the above processes is quenched.
  • the quenching is carried out at a cooling rate sufficient for making the whole thickness of the pipe into a martensitic microstructure.
  • Water cooling can be generally adapted.
  • the tempering is carried out at a temperature lower than the Ac 1 transformation point, desirably, at 600 to 700 degrees centigrade.
  • the tempering time may be about 20 to 60 minutes although it depends on the thickness of the pipe.
  • Billets with an outer diameter of 225 mm formed of 28 kinds of steels shown in Table 3 were produced. These billets were heated to 1250 degrees centigrade, and formed into seamless steel pipes with 244.5 mm outer diameter and 13.8 mm thickness by the Mannesmann-mandrel tube-making method.
  • Each formed seamless steel pipe was charged in a assistant heating furnace of a furnace temperature of 950 degrees centigrade constituting a heat treatment facility provided in the latter stage of a finish rolling machine (namely elongating and rolling machine), allowed to stand therein to uniformly and assistantly heated for 5 minutes, and then quenched in water.
  • a finish rolling machine namely elongating and rolling machine
  • the water-quenched seamless steel pipe was charged in a tempering furnace, and subjected to a tempering treatment of uniformly soaking at a temperature between 650 and 720 degrees centigrade for 30 minutes, and the strength was adjusted to about 110 ksi (758 MPa) in terms of yield strength to produce a product steel pipe, namely a seamless steel pipe for oil wells.
  • the grain size of the said water-quenched steel pipe was No. 7 or less by the grain size number regulated in JIS G 0551 (1998) in all the steels Nos. 1 to 28.
  • a Jominy test piece was taken from each billet before tube-making rolling, austenitized at 1100 degrees centigrade, and subjected to a Jominy test.
  • the hardenability was evaluated by comparing the Rockwell C hardness in a position 10 mm from a Jominy end (JHRC 10 ) with the value of 58C%+27, which is a predicted value of the Rockwell C hardness corresponding to 90%-martensite ratio of each steel, and determining one having a JHRC 10 higher than the value of 58C%+27 to have “excellent hardenability”, and one having a JHRC 10 not higher than the value of 58C%+27 to have “inferior hardenability”.
  • a circular tensile test piece regulated in 5CT of the API standard was cut off from the longitudinal direction of each steel pipe, and a tensile test was carried out to measure the yield strength YS (ksi), tensile strength TS (ksi) and yield ratio YR (%).
  • An A-method test piece regulated in NACE TM0177-96 was cut off from the longitudinal direction of each steel pipe, and an NACE A-method test was carried out in the circumstance of 0.5% acetic acid and 5% sodium chloride aqueous solution saturated with hydrogen sulfide of the partial pressure of 101325 Pa (1 atm) to measure a limit applied stress (that is maximum stress causing no rupture in a test time of 720 hours, shown by the ratio to the actual yield strength of each steel pipe).
  • the sulfide stress cracking resistance was determined to be excellent when the limit applied stress was 90% or more of YS.
  • Table 4 The examination results are shown in Table 4.
  • the column of hardenability of Table 4 is shown by “excellent” or “inferior” by comparison between JHRC 10 and the value of 58C%+27.
  • the steels Nos. 1 to 23 having chemical compositions regulated in the present invention, have excellent hardenability, high yield ratio, and excellent sulfide stress cracking resistance.
  • the steel No. 24 is too short of hardenability to obtain the uniform quenched and tempered microstructure, namely the uniform tempered martensitic microstructure, and also poor in sulfide stress cracking resistance with a low yield ratio, since the content of Mo is out of the range regulated in the present invention.
  • the steel No. 25 is too short of hardenability to obtain the uniform quenched and tempered microstructure, namely the uniform tempered martensitic microstructure, and also poor in sulfide stress cracking resistance with a low yield ratio, since the conditions regulated in the present invention are not satisfied with an A-value of the said equation (1) lower than 0.43 although the independent contents of C, Mn, Cr and Mo are within the ranges regulated in the present invention.
  • the steel No. 26 is excellent in hardenability and has a high yield ratio, but it is poor in sulfide stress cracking resistance since the content of Cr is higher than the regulation in the present invention.
  • the steel No. 27 is short of hardenability, and also poor in sulfide stress cracking resistance with a low yield ratio, since the content of Mo is lower than the lower limit value regulated in the present invention although the A-value of the said equation (1) satisfies the condition regulated in the present invention.
  • the steel No. 28 is excellent in hardenability, but it is inferior in sulfide stress cracking resistance with a low yield ratio, since the content of C is higher than the regulation of the present invention.
  • Billets with an outer diameter of 225 mm formed of 3 kinds of steels shown in Table 5 were produced. These billets were heated to 1250 degrees centigrade, and formed into seamless steel pipes with 244.5 mm outer diameter and 13.8 mm thickness by the Mannesmann-mandrel tube-making method. The steels Nos. 29 to 31 in Table 5 satisfied the chemical composition defined by the present invention.
  • Each formed seamless steel pipe was charged in a assistant heating furnace of a furnace temperature of 950 degrees centigrade constituting a heat treatment facility provided in the latter stage of a finish rolling machine (namely elongating and rolling machine), allowed to stand therein to uniformly and assistantly heated for 5 minutes, and then quenched in water.
  • a finish rolling machine namely elongating and rolling machine
  • the water-quenched seamless steel pipe was divided in two pieces and charged in a tempering furnace, and subjected to a tempering treatment of uniformly soaking for each piece at a temperature between 650 and 720 degrees centigrade for 30 minutes, and the strength was adjusted to about 125 ksi (862 MPa) to 135 ksi (931 MPa) in terms of tensile strength to produce a product steel pipe, namely a seamless steel pipe for oil wells.
  • the grain size of the said water-quenched steel pipe was No. 7 or less by the grain size number regulated in JIS G 0551 (1998) in all the steels Nos. 29 to 31.
  • a Jominy test piece was taken from each billet before tube-making rolling, austenitized at 1100 degrees centigrade, and subjected to a Jominy test.
  • the hardenability was evaluated by comparing the Rockwell C hardness in a position 10 mm from a Jominy end (JHRC 10 ) with the value of 58C%+27, which is a predicted value of the Rockwell C hardness corresponding to 90%-martensite ratio of each steel, and determining one having a JHRC 10 higher than the value of 58C%+27 to have “excellent hardenability”, and one having a JHRC 10 not higher than the value of 58C%+27 to have “inferior hardenability”.
  • a circular tensile test piece regulated in 5CT of the API standard was cut off from the longitudinal direction of each steel pipe, and a tensile test was carried out to measure the yield strength YS (ksi), tensile strength TS (ksi) and yield ratio YR (%).
  • An A-method test piece regulated in NACE TM0177-96 was cut off from the longitudinal direction of each steel pipe, and an NACE A-method test was carried out in the circumstance of 0.5% acetic acid and 5% sodium chloride aqueous solution saturated with hydrogen sulfide of the partial pressure of 101325 Pa (1 atm) to measure a limit applied stress (that is maximum stress causing no rupture in a test time of 720 hours, shown by the ratio to the actual yield strength of each steel pipe).
  • the sulfide stress cracking resistance was determined to be excellent when the limit applied stress was 90% or more of YS.
  • Table 6 The examination results are shown in Table 6.
  • the column of hardenability of Table 6 is shown by “excellent” or “inferior” by comparison between JHRC 10 and the value of 58C%+27.
  • the steels Nos. 29 to 31, having chemical compositions regulated in the present invention have excellent hardenability, high yield ratio, and excellent sulfide stress cracking resistance.
  • the marks 29-2, 30-2, 31-1 and 31-2 whose tensile strengths are not more than 130 ksi (897 MPa), have better sulfide stress cracking resistance.
  • the seamless steel pipe for oil wells of the present invention is highly strong and excellent in sulfide stress cracking resistance because it has a high yield ratio even with a quenched and tempered microstructure, namely a tempered martensitic microstructure, in which the prior-austenite grains are relatively coarse gains of No. 7 or less by the grain size number regulated in JIS G 0551 (1998).
  • the seamless steel pipe for oil wells of the present invention can be produced at a low cost by adapting an in-line tube making and heat treatment process having a high production efficiency since a reheating treatment for refinement of grains is not required.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Manufacturing & Machinery (AREA)
  • Heat Treatment Of Articles (AREA)
  • Heat Treatment Of Steel (AREA)
  • Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
US11/494,608 2004-01-30 2006-07-28 Seamless steel pipe for oil wells excellent in sulfide stress cracking resistance and method for producing the same Abandoned US20060266448A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US13/212,400 US9017494B2 (en) 2004-01-30 2011-08-18 Method for producing seamless steel pipe for oil wells excellent in sulfide stress cracking resistance

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2004-023470 2004-01-30
JP2004023470 2004-01-30
PCT/JP2005/001186 WO2005073421A1 (fr) 2004-01-30 2005-01-28 Canalisation en acier sans soudure pour puits de petrole excellente en termes de resistance a la corrosion fissurante provoquee par les sulfures et procede de production de celle-ci

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2005/001186 Continuation WO2005073421A1 (fr) 2004-01-30 2005-01-28 Canalisation en acier sans soudure pour puits de petrole excellente en termes de resistance a la corrosion fissurante provoquee par les sulfures et procede de production de celle-ci

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US13/212,400 Division US9017494B2 (en) 2004-01-30 2011-08-18 Method for producing seamless steel pipe for oil wells excellent in sulfide stress cracking resistance

Publications (1)

Publication Number Publication Date
US20060266448A1 true US20060266448A1 (en) 2006-11-30

Family

ID=34823873

Family Applications (2)

Application Number Title Priority Date Filing Date
US11/494,608 Abandoned US20060266448A1 (en) 2004-01-30 2006-07-28 Seamless steel pipe for oil wells excellent in sulfide stress cracking resistance and method for producing the same
US13/212,400 Expired - Fee Related US9017494B2 (en) 2004-01-30 2011-08-18 Method for producing seamless steel pipe for oil wells excellent in sulfide stress cracking resistance

Family Applications After (1)

Application Number Title Priority Date Filing Date
US13/212,400 Expired - Fee Related US9017494B2 (en) 2004-01-30 2011-08-18 Method for producing seamless steel pipe for oil wells excellent in sulfide stress cracking resistance

Country Status (13)

Country Link
US (2) US20060266448A1 (fr)
EP (1) EP1712651B1 (fr)
JP (1) JP4390081B2 (fr)
CN (1) CN100523256C (fr)
AR (1) AR047467A1 (fr)
AU (1) AU2005209562B2 (fr)
BR (1) BRPI0507314A (fr)
CA (1) CA2553586C (fr)
EA (1) EA010037B1 (fr)
MX (1) MXPA06008514A (fr)
NO (1) NO337651B1 (fr)
UA (1) UA82007C2 (fr)
WO (1) WO2005073421A1 (fr)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20150118837A1 (en) * 2013-10-30 2015-04-30 Taiwan Semiconductor Manufacturing Company, Ltd. Method Of Semiconductor Integrated Circuit Fabrication
US20160203895A1 (en) * 2013-08-20 2016-07-14 Jfe Steel Corporation Non-oriented electrical steel sheet and hot rolled steel sheet thereof
US20180355451A1 (en) * 2016-02-16 2018-12-13 Nippon Steel & Sumitomo Metal Corporation Seamless steel pipe and method of manufacturing the same
US10295456B2 (en) * 2014-10-01 2019-05-21 The Chugoku Electric Power Co., Inc. Remaining life estimation method for estimating remaining life of high-chromium steel pipe
US10597759B2 (en) 2013-08-20 2020-03-24 Jfe Steel Corporation Non-oriented electrical steel sheet having high magnetic flux density and motor
US10822678B2 (en) 2015-01-07 2020-11-03 Jfe Steel Corporation Non-oriented electrical steel sheet and method for producing the same
US11078558B2 (en) * 2016-10-06 2021-08-03 Nippon Steel Corporation Steel material, oil-well steel pipe, and method for producing steel material
US11155893B2 (en) * 2018-03-26 2021-10-26 Nippon Steel Corporation Steel material suitable for use in sour environment

Families Citing this family (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4635764B2 (ja) 2005-07-25 2011-02-23 住友金属工業株式会社 継目無鋼管の製造方法
MY144904A (en) * 2007-03-30 2011-11-30 Sumitomo Metal Ind Low alloy steel for oil country tubular goods and seamless steel pipe
AU2008221597B8 (en) * 2007-03-30 2010-04-22 Nippon Steel Corporation Low alloy steel, seamless steel oil country tubular goods, and method for producing seamless steel pipe
WO2009057390A1 (fr) * 2007-10-30 2009-05-07 Sumitomo Metal Industries, Ltd. Tube d'acier ayant d'excellentes propriétés d'agrandissement, et procédé de production de celui-ci
CN101413088B (zh) * 2008-12-02 2011-03-23 天津商业大学 耐硫化氢应力腐蚀的石油套管及其制造方法
KR101091306B1 (ko) * 2008-12-26 2011-12-07 주식회사 포스코 원자로 격납 용기용 고강도 강판 및 그 제조방법
CN101845597B (zh) * 2009-03-26 2011-12-21 宝山钢铁股份有限公司 低成本80公斤级特厚调质钢板及其制造方法
US20100319814A1 (en) * 2009-06-17 2010-12-23 Teresa Estela Perez Bainitic steels with boron
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
EP2325435B2 (fr) 2009-11-24 2020-09-30 Tenaris Connections B.V. Joint fileté étanche à des pressions internes et externes [extrêmement hautes]
US9163296B2 (en) 2011-01-25 2015-10-20 Tenaris Coiled Tubes, Llc Coiled tube with varying mechanical properties for superior performance and methods to produce the same by a continuous heat treatment
IT1403689B1 (it) 2011-02-07 2013-10-31 Dalmine Spa Tubi in acciaio ad alta resistenza con eccellente durezza a bassa temperatura e resistenza alla corrosione sotto tensioni da solfuri.
CN102690939B (zh) * 2011-03-25 2014-02-26 上海凯科管业有限公司 一种不锈钢无缝弯头的生产工艺
AR088424A1 (es) * 2011-08-22 2014-06-11 Nippon Steel & Sumitomo Metal Corp Tubo de acero para pozo de petroleo con excelente resistencia a la corrosion bajo tension por presencia de sulfuros
JP6107437B2 (ja) * 2012-06-08 2017-04-05 Ｊｆｅスチール株式会社 耐硫化物応力腐食割れ性に優れた油井用低合金高強度継目無鋼管の製造方法
KR101982014B1 (ko) * 2012-06-18 2019-05-24 제이에프이 스틸 가부시키가이샤 후육 고강도 내사우어 라인 파이프, 그의 제조 방법 및 그의 내hic성능의 판정 방법
EA025937B1 (ru) 2012-06-20 2017-02-28 Ниппон Стил Энд Сумитомо Метал Корпорейшн Сталь для трубных изделий нефтепромыслового сортамента и способ ее производства
IN2014KN02973A (fr) * 2012-07-09 2015-05-08 Jfe Steel Corp
JP6204496B2 (ja) 2013-01-11 2017-09-27 テナリス・コネクシヨンズ・ベー・ブイ 耐ゴーリング性ドリルパイプツールジョイントおよび対応するドリルパイプ
US9803256B2 (en) 2013-03-14 2017-10-31 Tenaris Coiled Tubes, Llc High performance material for coiled tubing applications and the method of producing the same
EP2789701A1 (fr) 2013-04-08 2014-10-15 DALMINE S.p.A. Tuyaux en acier sans soudure trempé et revenu à paroi moyenne haute résistance et procédé de fabrication des tuyaux d'acier
CN103194683B (zh) * 2013-04-24 2016-01-13 内蒙古包钢钢联股份有限公司 含稀土油井管接箍料用无缝钢管材料及其制备方法
KR102197204B1 (ko) 2013-06-25 2021-01-04 테나리스 커넥션즈 비.브이. 고크롬 내열철강
US10246765B2 (en) 2014-01-17 2019-04-02 Nippon Steel & Sumitomo Metal Corporation Martensitic Cr-containing steel and oil country tubular goods
WO2016013197A1 (fr) * 2014-07-22 2016-01-28 Ｊｆｅスチール株式会社 Procédé de test de fissuration à la contrainte de sulfure d'acier et tuyau en acier sans raccord ayant une excellente résistance à la fissuration à la contrainte de sulfure
CN104532132A (zh) * 2014-12-11 2015-04-22 宝山钢铁股份有限公司 一种高强度低合金抗硫化氢应力腐蚀用油井管及其制造方法
CN104513937A (zh) * 2014-12-19 2015-04-15 宝山钢铁股份有限公司 一种屈服强度800MPa级别高强钢及其生产方法
US11124852B2 (en) 2016-08-12 2021-09-21 Tenaris Coiled Tubes, Llc Method and system for manufacturing coiled tubing
CN106435373A (zh) * 2016-12-21 2017-02-22 重庆中鼎三正科技有限公司 一种低合金高强度抗硫化氢钢及其制备方法
US10434554B2 (en) 2017-01-17 2019-10-08 Forum Us, Inc. Method of manufacturing a coiled tubing string
WO2022120337A1 (fr) * 2020-12-04 2022-06-09 ExxonMobil Technology and Engineering Company Acier de tube de canalisation à compositions d'acier ordinaire différentes pour une résistance améliorée à la fissuration sous contrainte induite par sulfure
CN113025915B (zh) * 2021-03-04 2022-02-01 东北大学 一种高强韧性钒氮微合金化热轧钢管及其制造方法
CN114275735B (zh) * 2021-12-28 2023-04-07 安徽工业大学 一种含Mg室温可逆储氢高熵合金粉体材料及其制备方法

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4075041A (en) * 1976-06-14 1978-02-21 Nippon Steel Corporation Combined mechanical and thermal processing method for production of seamless steel pipe
US5938865A (en) * 1995-05-15 1999-08-17 Sumitomo Metal Industries, Ltc. Process for producing high-strength seamless steel pipe having excellent sulfide stress cracking resistance

Family Cites Families (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2567151B2 (ja) * 1990-12-28 1996-12-25 新日本製鐵株式会社 耐ｓｓｃ性の優れた油井用鋼管の製造法
JP2579094B2 (ja) 1991-12-06 1997-02-05 新日本製鐵株式会社 耐硫化物応力割れ性に優れた油井用鋼管の製造法
JPH06172859A (ja) * 1992-12-04 1994-06-21 Nkk Corp 耐硫化物応力腐食割れ性に優れた高強度鋼管の製造法
JPH06220536A (ja) * 1993-01-22 1994-08-09 Nkk Corp 耐硫化物応力腐食割れ性に優れた高強度鋼管の製造法
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
JPH07197125A (ja) * 1994-01-10 1995-08-01 Nkk Corp 耐硫化物応力腐食割れ性に優れた高強度鋼管の製造法
CN1064276C (zh) * 1994-10-20 2001-04-11 住友金属工业株式会社 无缝钢管的制造方法及其制造设备
JPH09111343A (ja) * 1995-10-18 1997-04-28 Nippon Steel Corp 高強度低降伏比シームレス鋼管の製造法
FR2744733B1 (fr) 1996-02-08 1998-04-24 Ascometal Sa Acier pour la fabrication de piece forgee et procede de fabrication d'une piece forgee
AR001655A1 (es) 1996-04-18 1997-11-26 Sumitomo Metal Ind Procedimiento para manufacturar tubos de acero sincostura y disposicion para el uso de dicho proced imiento
JP3855300B2 (ja) * 1996-04-19 2006-12-06 住友金属工業株式会社 継目無鋼管の製造方法および製造設備
FR2757877B1 (fr) 1996-12-31 1999-02-05 Ascometal Sa Acier et procede pour la fabrication d'une piece en acier mise en forme par deformation plastique a froid
JP4134377B2 (ja) * 1998-05-21 2008-08-20 住友金属工業株式会社 耐硫化物応力割れ性に優れた高強度鋼材の製造方法
JP2000017389A (ja) * 1998-06-29 2000-01-18 Sumitomo Metal Ind Ltd 靭性に優れたＣｒ−Ｍｏ系低合金鋼継目無鋼管およびその継目無鋼管用Ｃｒ−Ｍｏ系低合金鋼
JP3449311B2 (ja) * 1999-09-06 2003-09-22 住友金属工業株式会社 高靱性・高耐食性継目無鋼管

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4075041A (en) * 1976-06-14 1978-02-21 Nippon Steel Corporation Combined mechanical and thermal processing method for production of seamless steel pipe
US5938865A (en) * 1995-05-15 1999-08-17 Sumitomo Metal Industries, Ltc. Process for producing high-strength seamless steel pipe having excellent sulfide stress cracking resistance

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160203895A1 (en) * 2013-08-20 2016-07-14 Jfe Steel Corporation Non-oriented electrical steel sheet and hot rolled steel sheet thereof
US10006109B2 (en) * 2013-08-20 2018-06-26 Jfe Steel Corporation Non-oriented electrical steel sheet and hot rolled steel sheet thereof
US10597759B2 (en) 2013-08-20 2020-03-24 Jfe Steel Corporation Non-oriented electrical steel sheet having high magnetic flux density and motor
US20150118837A1 (en) * 2013-10-30 2015-04-30 Taiwan Semiconductor Manufacturing Company, Ltd. Method Of Semiconductor Integrated Circuit Fabrication
US9153483B2 (en) * 2013-10-30 2015-10-06 Taiwan Semiconductor Manufacturing Company, Ltd. Method of semiconductor integrated circuit fabrication
US11735477B2 (en) 2013-10-30 2023-08-22 Taiwan Semiconductor Manufacturing Company, Ltd. Method of semiconductor integrated circuit fabrication
US10295456B2 (en) * 2014-10-01 2019-05-21 The Chugoku Electric Power Co., Inc. Remaining life estimation method for estimating remaining life of high-chromium steel pipe
US10822678B2 (en) 2015-01-07 2020-11-03 Jfe Steel Corporation Non-oriented electrical steel sheet and method for producing the same
US20180355451A1 (en) * 2016-02-16 2018-12-13 Nippon Steel & Sumitomo Metal Corporation Seamless steel pipe and method of manufacturing the same
US11078558B2 (en) * 2016-10-06 2021-08-03 Nippon Steel Corporation Steel material, oil-well steel pipe, and method for producing steel material
US11155893B2 (en) * 2018-03-26 2021-10-26 Nippon Steel Corporation Steel material suitable for use in sour environment

Also Published As

Publication number Publication date
CN100523256C (zh) 2009-08-05
MXPA06008514A (es) 2006-08-28
AU2005209562A1 (en) 2005-08-11
US20110297279A1 (en) 2011-12-08
EP1712651B1 (fr) 2013-02-27
NO337651B1 (no) 2016-05-23
JPWO2005073421A1 (ja) 2007-09-13
EP1712651A4 (fr) 2007-12-26
CN1914343A (zh) 2007-02-14
AR047467A1 (es) 2006-01-18
NO20062911L (no) 2006-08-29
CA2553586A1 (fr) 2005-08-11
AU2005209562B2 (en) 2008-09-25
BRPI0507314A (pt) 2007-06-26
JP4390081B2 (ja) 2009-12-24
CA2553586C (fr) 2013-12-17
UA82007C2 (uk) 2008-02-25
WO2005073421A1 (fr) 2005-08-11
EP1712651A1 (fr) 2006-10-18
US9017494B2 (en) 2015-04-28
EA200601254A1 (ru) 2006-10-27
EA010037B1 (ru) 2008-06-30

Similar Documents

Publication Publication Date Title
US9017494B2 (en) Method for producing seamless steel pipe for oil wells excellent in sulfide stress cracking resistance
US8361256B2 (en) Method for producing seamless steel pipe
JP4632000B2 (ja) 継目無鋼管の製造方法
JP4305681B2 (ja) 継目無鋼管の製造方法
US10287645B2 (en) Method for producing high-strength steel material excellent in sulfide stress cracking resistance
JP2001271134A (ja) 耐硫化物応力割れ性と靱性に優れた低合金鋼材
JPH1150148A (ja) 高強度高耐食継目無鋼管の製造方法
JPH11310822A (ja) 低温靭性に優れた高強度マルテンサイト系ステンレス鋼管の製造法
JPH11286720A (ja) 耐硫化物応力割れ性に優れた高強度鋼材の製造方法
JPH1136017A (ja) 継目無鋼管用高強度非調質鋼の製造方法
JP2000313941A (ja) 表面品質に優れたマルテンサイト系ステンレス鋼継目無鋼管
JPH1177116A (ja) 高疲労強度鋼管の製造方法
JP2001323339A (ja) 低温靭性に優れた高強度マルテンサイト系ステンレス鋼管及びその製造方法
BRPI0507314B1 (pt) Sewer-free steel tube for oil wells

Legal Events

Date Code Title Description
AS Assignment

Owner name: SUMITOMO METAL INDUSTRIES, LTD., JAPAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:ARAI, YUJI;OMURA, TOMOHIKO;NAKAMURA, KEIICHI;REEL/FRAME:018492/0855;SIGNING DATES FROM 20060606 TO 20060612

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION