Claims
- 1. A process of making well casing characterized by improved hydrogen sulfide stress cracking resistance at high yield strengths ranging from about 90 to 145 ksi comprising the steps of providing an aluminum-killed steel consisting essentially in amounts by weight of from 0.10 to 0.40% carbon, 0.25 to 0.75% manganese, 0.05 to 0.50% silicon, 1.0 to 5.0% chromium, 0.30 to 1.0% molybdenum, 0.05 to 0.55% vanadium, 0.02 to 0.10% aluminum, and the balance iron except normal steel making impurities; rolling and forming the steel into tubular form; austenitizing the casing at a temperature of from 1550.degree. to 1700.degree. F., quenching the casing to obtain a microstructure which is essentially martensite, and tempering the casing at a temperature of from 1200.degree. to 1400.degree. F. to a maximum hardness of 35 R.sub.C and a microstructure which is essentially tempered martensite.
- 2. A process of making well casing characterized by improved hydrogen sulfide stress cracking resistance at high yield strengths ranging from about 90 to 145 ksi comprising the steps of providing an aluminum-killed steel consisting essentially in amounts by weight of from 0.15 to 0.35% carbon, 0.35 to 0.65% manganese, 0.10 to 0.35% silicon, 1.5 to 3.0% chromium, 0.40 to 0.80% molybdenum, 0.10 to 0.30% vanadium, about 0.02 to 0.08% aluminum, and the balance iron except normal steel making impurities; rolling and forming the steel into tubular form; austenitizing the casing at a temperature of from 1550.degree. to 1700.degree. F.; quenching the casing to obtain a microstructure which is essentially martensite, and tempering the casing at a temperature of from 1200.degree. to 1400.degree. F. to a maximum hardness of 35 R.sub.C and a microstructure which is essentially tempered martensite.
- 3. A process according to claim 1 or claim 2 wherein the steel includes 0.01 to 0.05% by weight columbium.
- 4. A process according to claim 1 or claim 2 wherein the steel includes one or more of the following elements in amounts by weight: 0 to 1.0% nickel, 0 to 0.25% titanium, 0 to 1.0% copper, 0 to 3.0% cobalt, 0 to 0.25% tungsten, 0 to 0.50% tantalum, and 0 to 0.10% columbium.
- 5. Quenched and tempered well casing characterized by improved hydrogen sulfide stress cracking resistance at high yield strengths ranging from about 90 to 145 ksi comprising an aluminum-killed steel consisting essentially in amounts by weight of from 0.10 to 0.40% carbon, 0.25 to 0.75% manganese, 0.05 to 0.50% silicon, 1.0 to 5.0% chromium, 0.30 to 1.0% molybdenum, 0.05 to 0.55% vanadium, 0.02 to 0.10% aluminum, and the balance iron except normal steel making impurities, the steel having a maximum hardness of 35 R.sub.C and a microstructure which is essentially tempered martensite.
- 6. Quenched and tempered well casing characterized by improved hydrogen sulfide stress cracking resistance at high yield strengths ranging from about 90 to 145 ksi comprised of an aluminum-killed steel consisting essentially in amounts by weight of from 0.15 to 0.35% carbon, 0.35 to 0.65% manganese, 0.10 to 0.35% silicon, 1.5 to 3.0% chromium, 0.40 to 0.80% molybdenum, 0.10 to 0.30% vanadium, about 0.02 to 0.08% aluminum, and the balance iron except normal steel making impurities, the steel having a maximum hardness of 35 R.sub.C and a microstructure which is essentially tempered martensite.
- 7. Well casing according to claim 5 or claim 6 wherein the steel includes 0.01 to 0.05% by weight columbium.
- 8. Well casing according to claim 5 or claim 6 wherein the steel includes one or more of the following elements in amounts by weight: 0 to 1.0% copper, 0 to 3.0% cobalt, 0 to 0.25% tungsten, 0 to 0.50% tantalum, and 0 to 0.10% columbium.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 866,754 entitled Well Casing Steel, filed Jan. 3, 1978 and now abandoned, which was a continuation-in-part of application Ser. No. 752,441 filed Dec. 20, 1976 for Well Casing Steel and now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
3992231 |
Timmons |
Nov 1976 |
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
866754 |
Jan 1978 |
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Parent |
752441 |
Dec 1976 |
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