US2002104592A1PendingUtilityA1
High strength steel material for oil well, excellent in sulfide stress cracking resistance, and production method thereof
Priority: May 6, 1999Filed: Nov 6, 2001Published: Aug 8, 2002
Est. expiryMay 6, 2019(expired)· nominal 20-yr term from priority
C22C 38/14C22C 38/12C21D 1/18C22C 38/06C22C 38/001
42
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Claims
Abstract
This invention provides a high-strength steel material for an oil well, excellent in strength and SSC resistance, and having a yield strength of at least 120 ksi. The steel material contains C: 0.10 to 0.40%, Si≦0.5%, Mn≦0.5%, P≦0.015%, S≦0.0050%, Mo: 0.5 to 2.5%, Al: 0.005 to 0.1%, Ti: 0.005 to 0.1% and at least 3.4 times N, Nb: 0.01 to 0.1%, N≦0.01% and B: 0.0005 to 0.0050%, wherein the yield strength expressed by ksi and the Mo content satisfy the following relation (1), the balance of the C, Mn and Mo contents satisfies the following relation (2), and the steel material may contain, whenever necessary, at least one of Cr≦0.2%, W≦0.5%, V: 0.01 to 0.3%, Zr: 0.001 to 0.01%, Ca: 0.001 to 0.01%, Mg: 0.001 to 0.01% and REM: 0.001 to 0.01%: α=Mo−0.15YS ≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
Claims
exact text as granted — not AI-modified1 . A high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn≦0.5%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the MO content satisfy the following relation (1) and the balance of the C, MN and MO contents satisfies the following relation (2):
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
2 . A high-strength steel material, for an oil, excellent in sulfide stress cracking resistance, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn≦0.5%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of C, Mn and Mo contents satisfies the following relation (2);
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2), and
wherein said steel material contains further at least one of the following elements:
W≦0.5%,
V: 0.01 to 0.3%,
Zr: 0.001 to 0.010%,
Ca: 0.001 to 0.01%,
Mg: 0.001 to 0.01% and
REM: 0.001 to 0.01%.
3 . A high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn<0.3%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2):
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
4 . A high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn<0.3%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2); and
Wherein said steel material contains further at least one of the following elements:
W≦0.5%,
V: 0.01 to 0.3%,
Zr: 0.001 to 0.010%,
Ca: 0.001 to 0.01%,
Mg: 0.001 to 0.01% and
REM: 0.001 to 0.01%:
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
5 . A high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance and having a yield strength of at least 120 ksi, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn<0.5%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2).
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
6 . A high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance and having a yield strength of at least 120 ksi, containing, in terms of mass %:
C: 0.10 to 0.40%,
Si≦0.5%,
Mn≦0.5%,
P≦0.015%,
S≦0.0050%,
Mo: 0.5 to 2.5%,
Al: 0.005 to 0.1%,
Ti: 0.005 to 0.1% and at least 3.4 times N%,
Nb: 0.01 to 0.1%,
N≦0.01% and
B: 0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2); and
wherein said steel material further contains at least one of the following elements:
W ≦
0.5%,
V:
0.01 to 0.3%,
Zr:
0.001 to 0.010%,
Ca:
0.001 to 0.01%,
Mg:
0.001 to 0.01% and
REM:
0.001 to 0.01%:
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
7 . A high-strength steel material for an oil well, excellent in sulfide stress cracking resistance and having a yield strength of at least 120 ksi, containing, in terms of mass %:
C:
0.10 to 0.40%,
Si ≦
0.5%,
Mn <
0.3%,
P ≦
0.015%,
S ≦
0.0050%,
Mo:
1.0 to 2.5%,
Al:
0.0050 to 0.1%,
Ti:
0.005 to 0.1% and
at least 3.4 times N%,
Nb:
0.01 to 0.1%,
N ≦
0.01% and
B:
0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2):
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
8 . A high-strength steel material for an oil well, excellent in sulfide stress cracking resistance and having a yield strength of at least 120 ksi, containing, in terms of mass %:
C:
0.10 to 0.40%,
Si ≦
0.5%,
Mn <
0.3%,
P ≦
0.015%,
S ≦
0.0050%,
Mo:
1.0 to 2.5%,
Al:
0.005 to 0.1%,
Ti:
0.0050 to 0.1% and
at least 3.4 times N%,
Nb:
0.01 to 0.1%,
N ≦
0.01% and
B:
0.0005 to 0.0050%,
wherein the yield strength YS expressed by ksi and the Mo content satisfy the following relation (1) and the balance of the C, Mn and Mo contents satisfies the following relation (2); and
wherein said steel material further contains at least one of the following elements:
W ≦
0.5%,
V:
0.01 to 0.3%,
Zr:
0.001 to 0.010%,
Ca:
0.001 to 0.01%,
Mg:
0.001 to 0.01% and
REM:
0.001 to 0.01%:
α=Mo−0.15YS≧−18.9 (1) β=2.7C+Mn+2Mo≧2.0 (2).
9 . A method of producing a high-strength steel material, for an oil well, excellent in sulfide stress cracking resistance, said method comprising the steps of:
hot processing said steel containing said components according to any of claims 1 through 8 and having the balance of the C, Mn and Mo contents satisfying the following relation (2); heating for austenitizing said steel material to a temperature within the range of [Ac 3 point+20° C.] to 1,000° C.; quenching said steel material to obtain a microstructure in which the hardness as-quenched at the remotest position of said steel material from the cooled surface thereof is at least 95% of the hardness of the cooled surface; and tempering said steel material at a temperature of 620 to 720° C.: β=2.7C+Mn+2Mo≧2.0 (2).
10 . A high-strength steel material for an oil well excellent in sulfide stress cracking, according to any of claims 1 through 9 , wherein a threshold stress for crack occurrence determined by a constant load type sulfide stress cracking test according to NACE TM0177-A is at least 80% of the yield strength.Join the waitlist — get patent alerts
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