公开(公告)号：EP2447386A4

公开(公告)日：2016-06-15

申请号：EP10792232

申请日：2010-06-23

Applicant: JFE STEEL CORP

Inventor： EGUCHI KENICHIRO ,  TANAKA YUJI ,  KIMURA MITSUO ,  ISHIGURO YASUHIDE ,  YAMADA KATSUMI ,  NAKAMICHI HARUO

IPC: C22C38/00 ,  C21D9/08 ,  C21D9/14 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: C21D9/14 ,  C21D2211/004 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

Abstract: Provided is a high-strength seamless steel tube, having excellent resistance to sulfide stress cracking (SSC resistance), for oil wells. In particular, the seamless steel tube contains 0.15% to 0.50% C, 0.1% to 1.0% Si, 0.3% to 1.0% Mn, 0.015% or less P, 0.005% or less S, 0.01% to 0.1% Al, 0.01% or less N, 0.1% to 1.7% Cr, 0.4% to 1.1% Mo, 0.01% to 0.12% V, 0.01% to 0.08% Nb, and 0.0005% to 0.003% B or further contains 0.03% to 1.0% Cu on a mass basis and has a microstructure which has a composition containing 0.40% or more solute Mo and a tempered martensite phase that is a main phase and which contains prior-austenite grains with a grain size number of 8.5 or more and 0.06% by mass or more of a dispersed M 2 C-type precipitate with substantially a particulate shape.

公开(公告)号：EP2918697A4

公开(公告)日：2016-03-09

申请号：EP13864497

申请日：2013-12-19

Applicant: JFE STEEL CORP

Inventor： EGUCHI KENICHIRO ,  ISHIGURO YASUHIDE

IPC: C22C38/00 ,  C21D1/18 ,  C21D6/00 ,  C21D8/10 ,  C21D9/08 ,  C21D11/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: C21D9/08 ,  C21D1/18 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/105 ,  C21D9/085 ,  C21D11/00 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

Abstract: [Solution to Problem] On a percent by mass basis, C: 0.05% or less, Si: 0.5% or less, Mn: 0.15% to 1.0%, P: 0.030% or less, S: 0.005% or less, Cr: 15.5% to 17.5%, Ni: 3.0% to 6.0%, Mo: 1.5% to 5.0%, Cu: 4.0% or less, W: 0.1% to 2.5%, and N: 0.15% or less are contained in such a way that -5.9 x (7.82 + 27C - 0.91Si + 0.21Mn - 0.9Cr + Ni - 1.1Mo + 0.2Cu + 11N) ‰¥ 13.0 is satisfied. Consequently, a high-strength stainless steel seamless tube or pipe having excellent corrosion resistance can be produced, where excellent carbon dioxide gas corrosion resistance at high-temperature environments containing CO 2 and Cl - at high temperatures up to 200°C and excellent sulfide stress cracking resistance and excellent sulfide stress corrosion cracking resistance at corrosive environments further containing H 2 S are ensured in combination. In this regard, V, and/or Al, and/or at least one selected from the group consisting of Nb, Ti, Zr, and B, and/or at least one selected from the group consisting of REM, Ca, and Sn may be further contained.

公开(公告)号：EP2857530A4

公开(公告)日：2015-11-04

申请号：EP13796392

申请日：2013-05-30

Applicant: JFE STEEL CORP

Inventor： MIYATA YUKIO ,  ISHIGURO YASUHIDE ,  ISHIKAWA KAZUTOSHI ,  NAKAHASHI TETSU

IPC: C21D8/10 ,  C21D9/08 ,  C22C38/00 ,  C22C38/58

CPC classification number: C22C38/54 ,  C21D8/10 ,  C21D8/105 ,  C21D9/08 ,  C21D9/085 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50

Abstract: Provided is a high-strength stainless steel tube for oil country tubular goods having a wall thickness of more than 25.4 mm and a high strength of a 110 ksi (758 MPa) grade yield stress or more with excellent toughness and excellent corrosion resistance. A steel material having a chemical composition containing, by mass%, C: 0.005% or more and 0.06% or less, Si: 0.05% or more and 0.5% or less, Mn: 0.2% or more and 1.8% or less, Cr: 15.5% or more and 18.0% or less, Ni: 1.5% or more and 5.0% or less, V: 0.02% or more and 0.2% or less, Al: 0.002% or more and 0.05% or less, N: 0.01% or more and 0.15% or less, O: 0.006% or less, and further containing one or more of Mo: 1.0% or more and 3.5% or less, W: 3.0% or less and Cu: 3.5% or less, in which the relational expressions Cr+0.65Ni+0.60Mo+0.30W+0.55Cu-20C‰¥19.5 and Cr+Mo+0.50W+0.30Si-43.5C-0.4Mn-Ni-0.3Cu-9N‰¥11.5 are satisfied, is made into a seamless steel tube by performing heating and hot rolling. The hot rolling is performed under conditions such that the total rolling reduction in a temperature range of 1100°C to 900°C is 30% or more. After the hot rolling has been performed, cooling is performed at a cooling rate equal to or more than an air-cooling rate, and, further, quenching-tempering is performed. With this method, a high-strength and high-toughness seamless steel tube having a strength of 110 ksi (758 MPa) or more and a toughness of 40 J or more in terms of vE- 10 despite having a thick wall and excellent corrosion resistance even in a high-temperature corrosion environment having a temperature of 230°C and containing CO 2 and Cl - can be stably manufactured.

公开(公告)号：EP3321389A4

公开(公告)日：2018-05-16

申请号：EP16824022

申请日：2016-06-13

Applicant: JFE STEEL CORP

Inventor： EGUCHI KENICHIRO ,  ISHIGURO YASUHIDE ,  SUZUKI TAKESHI ,  FUJIMURA KAZUKI ,  OTA HIROKI

IPC: C22C38/00 ,  C21D1/18 ,  C21D6/00 ,  C21D8/10 ,  C21D9/08 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

CPC classification number: C21D9/08 ,  C21D1/18 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/105 ,  C21D9/085 ,  C21D2211/001 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

Abstract: Provided is a high-strength seamless stainless steel pipe which can acquire high strength and high toughness together with excellent corrosion resistance while preventing frequent occurrence of rolling flaws. A steel pipe raw material having a composition comprising, by mass%, 0.05% or less C, 1.0% or less Si, 0.1 to 0.5% Mn, 0.05% or less P, 0.005% or less S, more than 16.0% to 18.0% or less Cr, more than 2.0% to 3.0% or less Mo, 0.5 to 3.5% Cu, 3.0% or more and less than 5.0% Ni, 0.01 to 3.0% W, 0.01 to 0.5% Nb, 0.001 to 0.3% Ti, 0.001 to 0.1% Al, less than 0.07% N, and 0.01% or less O is heated at a heating temperature which falls within a range of 1210 to 1350°C and at which an average grain size A (µm) of precipitates of Ti and Nb at the heating temperature and a sum of amounts B (mass%) of precipitated Ti and Nb satisfy A /B 2/3 ‰¤14.0. A seamless steel pipe is formed by applying hot pipe forming to the heated steel pipe raw material. The seamless steel pipe is cooled and, thereafter, quenching treatment is performed at a heating temperature of 850 to 1050°C. Then, tempering treatment is performed. Thus, it is possible to provide a high-strength seamless stainless steel pipe which has high strength having yield strength YS of 758MPa or more, high toughness having an absorbing energy value vE -10 of 40J or more, and excellent corrosion resistance.

公开(公告)号：EP3173764A4

公开(公告)日：2017-07-26

申请号：EP15824727

申请日：2015-07-17

Applicant: JFE STEEL CORP

Inventor： YUGA MASAO ,  ISHIGURO YASUHIDE ,  FUJIMURA KAZUKI ,  OKATSU MITSUHIRO ,  SUGANO YOSHIYUKI

IPC: G01N3/08 ,  C22C38/00 ,  C22C38/50 ,  G01N17/00

CPC classification number: G01N17/006 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  G01N3/08 ,  G01N17/00

Abstract: When the resistance to sulfide stress corrosion cracking is evaluated by applying a constant load stress à (MPa) to a round bar tensile test specimen immersed in a test solution and checking whether failure occurs before a particular time passes, the round bar tensile test specimen including a parallel section, a shoulder section, and a grip section is used. In the round bar tensile test specimen, the shoulder section is formed by a curve having two or more radii of curvature, a radius of curvature R1 (mm) of a portion adjacent to the parallel section is 15 mm or more and satisfies (0.22à - 119) ‰¤ R1 ‰¤ 100, a length X1 (mm) of a portion of the curve having the radius of curvature R1 in a longitudinal direction of the test specimen satisfies X1 ‰¥ ˆš{(r/8) × (R1 - r 2 /4)} (r: radius (mm) of the round bar tensile test specimen in the parallel section), and the radius of curvature R1 is larger than other radii of curvature. Thus, even when the steel is a high-strength steel having a yield strength of 758 MPa or higher, the occurrence of the failure in the shoulder section is suppressed, and the resistance to sulfide stress corrosion cracking can be properly evaluated.

Abstract translation: 当通过对浸入试验溶液中的圆棒拉伸试验样品施加恒定负荷应力（MPa）并且在特定时间过后检查是否发生破坏来评价耐硫化物应力腐蚀开裂性能时，圆棒拉伸试验样品包括 平行部分，肩部部分和把手部分。 在圆棒拉伸试验片中，肩部由具有两个以上曲率半径的曲线形成，与平行部相邻的部分的曲率半径R1（mm）为15mm以上，满足（0.22× -119）≤R1≤100，曲率半径R1在试验片长度方向上的曲率部分的长度X1（mm）满足下式：（R1）×（R1 - r 2/4）}（r：平行截面中的圆棒拉伸试验片的半径（mm）），曲率半径R1大于其他曲率半径。 因此，即使在钢为屈服强度为758MPa以上的高强度钢的情况下，也能够抑制肩部的失效发生，能够适当地评价耐硫化物应力腐蚀开裂性。

公开(公告)号：EP2952592A4

公开(公告)日：2016-04-27

申请号：EP14746700

申请日：2014-01-22

Applicant: JFE STEEL CORP

Inventor： SUZUKI TAKESHI ,  EGUCHI KENICHIRO ,  ISHIGURO YASUHIDE

IPC: C21D9/08 ,  C22C38/00 ,  C22C38/58

CPC classification number: C21D9/08 ,  C21D1/18 ,  C21D11/005 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/58

Abstract: It is difficult in the related art to realize not only a decrease in material variability due to non-uniform microstructure distribution in the wall thickness direction of a pipe body but also the maintenance of satisfactory productivity of the whole heat treatment line at the same time. A method includes determining in advance whether or not the pipe body is made of a steel grade having an Ms point lower than 200°C; leaving the pipe body of a steel grade having an Ms point lower than 200°C additionally at room temperature (it is preferable to be transported to a holding bed 6 and left) until the temperature difference between the portion having the highest temperature and the portion having the lowest temperature in a cross section in a direction at a right angle to the pipe axis becomes less than 2.0°C after the quenching treatment has been performed, and then performing the tempering treatment; and, on the other hand, performing a tempering treatment on the pipe body of a steel grade not having an Ms point lower than 200°C without leaving the pipe body at room temperature after a quenching treatment has been performed.

公开(公告)号：EP3202943A4

公开(公告)日：2018-01-10

申请号：EP15872121

申请日：2015-09-10

Applicant: JFE STEEL CORP

Inventor： YUGA MASAO ,  ISHIGURO YASUHIDE ,  NABESHIMA SEIJI ,  OKATSU MITSUHIRO ,  OTA HIROKI

IPC: C22C38/00 ,  C21D8/10 ,  C21D9/08 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/54

CPC classification number: C21D9/085 ,  C21D1/18 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/10 ,  C21D8/105 ,  C21D9/08 ,  C21D9/46 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/18 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/32 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54

Abstract: Provided is a high-strength seamless steel pipe for oil country tubular goods having superior sulfide stress cracking resistance. The seamless steel pipe contains, by mass%, C: 0.20% to 0.50%, Si: 0.05% to 0.40%, Mn: more than 0.6% and 1.5% or less, P: 0.015% or less, S: 0.005% or less, Al: 0.005% to 0.1%, N: 0.006% or less, Mo: more than 1.0% and 3.0% or less, V: 0.05% to 0.3%, Nb: 0.001% to 0. 020%, B: 0.0003% to 0. 0030%, O: 0.0030% or less, and Ti: 0.003% to 0.025%, in which Ti/N: 2.0 to 5.0 is satisfied, a volume fraction of a tempered martensitic is 95% or more, prior austenite grains have a grain size number of 8.5 or more, and in a cross-section perpendicular to a rolling direction, the number of nitride-based inclusions having a grain size of 4 µm or more is 100 or less per 100 mm 2 , the number of nitride-based inclusions having a grain size of less than 4 µm is 1000 or less per 100 mm 2 , the number of oxide-based inclusions having a grain size of 4 µm or more is 40 or less per 100 mm 2 , and the number of oxide-based inclusions having a grain size of less than 4 µm is 400 or less per 100 mm 2 .

公开(公告)号：EP3246418A4

公开(公告)日：2017-11-22

申请号：EP15877751

申请日：2015-12-03

Applicant: JFE STEEL CORP

Inventor： FUJIMURA KAZUKI ,  ISHIGURO YASUHIDE ,  GOTO SEIGO

IPC: C21D8/10 ,  C21D6/00 ,  C21D9/08 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/40 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

CPC classification number: C21D9/085 ,  C21D1/25 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/10 ,  C21D8/105 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/40 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

Abstract: Provided are a method of manufacturing a seamless stainless steel pipe for Oil Country Tubular Goods with excellent hot workability, by which a seamless stainless steel pipe for Oil Country Tubular Goods having high strength of 110ksi (=758MPa) or more in terms of yield strength, high toughness of 40J or more in terms of absorption energy vE -10 in a Charpy impact test at a test temperature of -10°C and excellent corrosion resistance can be acquired, and a seamless stainless steel pipe for Oil Country Tubular Goods acquired by the method. A billet which has the composition containing predetermined components and in which the contents of C, Si, Mn, Cr, Mo, Ni, N, W, Cu satisfy the predetermined relationship is heated, hot working is applied to the billet thus forming a seamless steel pipe, the seamless steel pipe is cooled to a room temperature at a cooling rate of air cooling or more, thereafter, quenching is performed by heating the seamless steel pipe to a temperature of 850°C or above and, subsequently, by cooling the seamless steel pipe to a temperature of 100 °C or below at a cooling rate of air cooling or more and, subsequently, tempering is applied to the seamless steel pipe at a temperature of 700°C or below for a predetermined holding time.

公开(公告)号：EP2947167A4

公开(公告)日：2016-01-13

申请号：EP14740356

申请日：2014-01-14

Applicant: JFE STEEL CORP

Inventor： EGUCHI KENICHIRO ,  ISHIGURO YASUHIDE

IPC: C21D1/22 ,  C21D8/10 ,  C21D9/08 ,  C21D9/14 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58

CPC classification number: C21D9/14 ,  C21D1/22 ,  C21D6/004 ,  C21D6/005 ,  C21D6/008 ,  C21D8/105 ,  C21D9/08 ,  C21D2211/001 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/42 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/54 ,  C22C38/58 ,  E21B17/00

公开(公告)号：EP2728030A4

公开(公告)日：2015-09-02

申请号：EP12805050

申请日：2012-06-29

Applicant: JFE STEEL CORP

Inventor： ISHIGURO YASUHIDE ,  KIMURA MITSUO ,  EGUCHI KENICHIRO ,  YOKOGAWA HIROSHI ,  KATAGIRI TADAO ,  TANAKA MASAHITO

IPC: C22C38/00 ,  C21D1/18 ,  C21D3/04 ,  C21D9/08 ,  C22C38/14 ,  C22C38/58

CPC classification number: C21D9/085 ,  C21D1/25 ,  C21D1/63 ,  C21D8/105 ,  C21D2261/00 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/28 ,  C22C38/38 ,  C22C38/40 ,  C22C38/44 ,  C22C38/46 ,  C22C38/48 ,  C22C38/50 ,  C22C38/58 ,  F16L9/02

Abstract: A heavy wall and high strength seamless steel pipe having high sour resistance is provided. In particular, a quenching and tempering treatment is conducted to adjust the yield strength to be higher than 450 MPa and adjust the wickers hardness HV5 that can be measured at an outermost side or an innermost side of the pipe under a 5 kgf load (test load: 49 N) to be 250 HV5 or less. In order to achieve this, surface layers are ground from surfaces by a depth of 0.3 mm or more in a wall thickness direction after the quenching treatment, or the quenching treatment is designed to include holding a heating temperature equal to or higher than the Ac3 transformation point for 120 seconds or more in an air atmosphere and then performing water-cooling in a nucleate boiling region or performing water-cooling in a film boiling region and then in a nucleate boiling region. As a result of this quenching treatment, the hardness of the surface layers decreases to 250 HV5 or less and a steel pipe that has an M-shape hardness distribution in which the maximum hardness appears at some point in the profile other than the center of the wall or a U-shape hardness distribution in which the hardness of the surface layers is the highest but not more than 250 HV5 or a flat shape hardness distribution can be obtained. As a result, the sour resistance is significantly improved.