Granted Patent B2

US 12,365,960 · App. 17/297,388 · Granted Jul 22, 2025

Inventors: Rainer Fluch (St. Lorenzen im Mürztal, AT); Andreas Keplinger (Leoben, AT); Martin Wöls (Aflenz, AT); Bernd Holper (Pinkafeld, AT); Walter Spruzina (Aue, AT)

Assignees: Voestalpine BOHLER Edelstahl GmbH & Co.; Schoeller-Bleckmann Oilfiend Technology

C21D9/44C21D6/004C21D6/005C21D6/008C21D8/065C22C38/001C22C38/02C22C38/42C22C38/44C22C38/46C22C38/58E21B17/00C21D2211/001

Abstract

Claims (134)

1. A drill string component, comprising an alloy including the following elements in percent by weight:

Elements

Carbon (C)

0.01-0.10

Silicon (Si)

<0.5

Manganese (Mn)

5.0-6.0

Phosphorus (P)

<0.05

Sulfur (S)

<0.005

Chromium (Cr)

26.0-28.0

Molybdenum (Mo)

2.5-3.5

Nickel (Ni)

13.0-15.0

Vanadium (V)

below detection level

Tungsten (W)

below detection level

Copper (Cu)

<0.1

Cobalt (Co)

below detection level

Titanium (Ti)

below detection level

Aluminum (Al)

<0.1

Niobium (Nb)

below detection level

Boron (B)

<0.01

Nitrogen (N)

0.54-0.80

Iron (Fe) and

inevitable impurities residual.

2. The drill string component according to claim 1 , wherein the alloy comprises the copper in an amount of greater than zero.

3. The drill string component according to claim 1 , wherein the drill string component is produced by a method that includes secondary metallurgical processing of the alloy, casting the alloy into blocks immediately followed by hot forging, cold forming the alloy, and optionally subjecting the alloy to further mechanical processing.

4. The drill string component according to claim 3 , wherein after the cold forming, the alloy has a magnetic permeability μr of less than about 1.01.

5. The drill string component according to claim 3 , wherein the method further comprises strain hardening the alloy, wherein after the strain hardening, the alloy has a yield strength R p0.2 of greater than about 1000 MPA.

6. The drill string component according to claim 5 , wherein after the strain hardening, the alloy has a notched bar impact work at 20° C. of greater than about 80 J.

7. The drill string component according to claim 3 , wherein after the cold forming, the alloy is fully austenitic.

8. A method for producing a drill string component, comprising the steps of: providing an alloy including the following elements in percent by weight:

Elements

Carbon (C)

0.01-0.10

Silicon (Si)

<0.5

Manganese (Mn)

5.0-6.0

Phosphorus (P)

<0.05

Sulfur (S)

<0.005

Chromium (Cr)

26.0-28.0

Molybdenum (Mo)

2.5-3.5

Nickel (Ni)

13.0-15.0

Vanadium (V)

below detection level

Tungsten (W)

below detection level

Copper (Cu)

<0.1

Cobalt (Co)

below detection level

Titanium (Ti)

below detection level

Aluminum (Al)

<0.1

Niobium (Nb)

below detection level

Boron (B)

<0.005

Nitrogen (N)

0.54-0.80

Iron (Fe) and

inevitable impurities residual;

melting the alloy:

subjecting the alloy to secondary metallurgical processing:

casting the alloy into blocks;

solidifying the alloy:

heating and immediately hot forming the alloy;

cold forming the alloy.

9. The method according to claim 8 , wherein the hot forming comprises a plurality of sub-steps.

10. The method according to claim 9 , further comprising reheating the alloy in between the hot forming sub-steps and after a last of the hot forming sub-steps and solution annealing the alloy after the last hot forming sub-step.

11. A steel alloy useful in forming a drill string component, comprising the following elements in percent by weight:

Elements

Carbon (C)

0.01-0.10

Silicon (Si)

<0.5

Manganese (Mn)

5.0-6.0

Phosphorus (P)

<0.05

Sulfur (S)

<0.005

Chromium (Cr)

26.0-28.0

Molybdenum (Mo)

2.5-3.5

Nickel (Ni)

13.0-15.0

Vanadium (V)

below detection level

Tungsten (W)

below detection level

Copper (Cu)

<0.1

Cobalt (Co)

below detection level

Titanium (Ti)

below detection level

Aluminum (Al)

<0.1

Niobium (Nb)

below detection level

Boron (B)

<0.01

Nitrogen (N)

0.54-0.80

Iron (Fe) and

inevitable impurities residual.

12. The steel alloy of claim 11 , wherein the alloy comprises a superaustenite having a PREN 16 of α>42, where PREN=% Cr+3.3×% Mo+16×% N.

13. The steel alloy of claim 11 , wherein the alloy has a magnetic permeability μr of less than about 1.01.

14. The steel alloy of claim 13 , wherein the magnetic permeability μr is less than about 1.005.

15. The steel alloy of claim 11 , wherein the steel alloy has a yield strength R p0.2 greater than about 500 MPa.

16. The steel alloy of claim 15 , wherein the yield strength R p0.2 is greater than about 1000 MPa.

17. The steel alloy of claim 11 , wherein the steel alloy has a tensile strength Rm of at least about 1100 MPa.

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (40)