Component for use in oil field technology made of a material which comprises a corrosion-resistant austenitic steel alloy
AssigneesBoehler Edelstahl GmbH & Co. KG, Schoeller-Bleckmann Oilfield Technology GmbH
InventorsGabriele Saller, Herbert Aigner, Josef Bernauer, Raimund Huber
Life of this patent
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Abstract
An austenitic, substantially ferrite-free steel alloy and a process for producing components therefrom. This Abstract is not intended to define the invention disclosed in the specification, nor intended to limit the scope of the invention in any way.
Claims59
A component for use in oil field technology, wherein the component comprises a drilling string part and is made of a material which comprises an austenitic, substantially ferrite-free steel alloy comprising, in % by weight:
- from about 0% to about 0.35% of carbon
- from about 0% to about 0.75% of silicon
- from more than about 20.0% to about 30.0% of manganese
- from more than about 17.0% to about 24.0% of chromium
- from more than 1.90% to about 5.5% of molybdenum
- from about 0% to about 2.0% of tungsten
- from 3.6% to about 15.0% of nickel
- from about 0% to about 5.0% of cobalt
- from 0.60% to about 1.05% of nitrogen
- from about 0% to about 0.005% of boron
- from about 0% to about 0.30% of sulfur
- from about 0% to less than about 0.5% of copper
- from about 0% to less than about 0.05% of aluminum
- from about 0% to less than about 0.035% of phosphorus,
- and optionally one or more elements selected from vanadium, niobium and titanium in a total concentration of not more than about 0.85%, balance iron and production-related impurities, and wherein the drilling string part has a fatigue strength under reversed stresses at room temperature of greater than about 400 MPa at 107 load alternation.
A component for use in oilfield technology, wherein the component has a fatigue strength under reversed stresses at room temperature of greater than about 400 MPa at 107 load alternation and has been obtained by a process which comprises:
- (a) forming a cast piece of an alloy into a semi-finished product in two or more hot working partial operations at a temperature of above about 750° C., the alloy comprising, in % by weight:
- from about 0% to about 0.35% of carbon
- from about 0% to about 0.75% of silicon
- from more than about 20.0% to about 30.0% of manganese
- from more than about 17.0% to about 24.0% of chromium
- from more than 1.90% to about 5.5% of molybdenum
- from about 0% to about 2.0% of tungsten
- from 3.6% to about 15.0% of nickel
- from about 0% to about 5.0% of cobalt
- from about 0.60% to about 1.05% of nitrogen
- from about 0% to about 0.005% of boron
- from about 0% to about 0.30% of sulfur
- from about 0% to less than about 0.5% of copper
- from about 0% to less than about 0.05% of aluminum
- from about 0% to less than about 0.035% of phosphorus,
- and optionally one or more elements selected from vanadium, niobium and titanium in a total concentration of not more than about 0.85%, balance iron and production-related impurities,
- (b) subjecting the semi-finished product to intensified cooling, and
- (c) working the cooled semi-finished product at a temperature below a recrystallization temperature.
A component for use in oilfield technology, wherein the component has a fatigue strength under reversed stresses at room temperature of greater than about 400 MPa at 107 load alternation and has been obtained by a process which comprises:
- (a) forming a cast piece of an alloy into a semi-finished product in two or more hot working partial operations at a temperature of above about 750° C., the alloy comprising, in % by weight:
- from about 0% to about 0.35% of carbon
- from about 0% to about 0.75% of silicon
- from more than about 20.0% to about 30.0% of manganese
- from more than about 17.0% to about 24.0% of chromium
- from more than 1.90% to about 5.5% of molybdenum
- from about 0% to about 2.0% of tungsten
- from about 3.8% to about 15.0% of nickel
- from about 0% to about 5.0% of cobalt
- from about 0.60% to about 1.05% of nitrogen
- from about 0% to about 0.005% of boron
- from about 0% to about 0.30% of sulfur
- from about 0% to less than about 0.5% of copper
- from about 0% to less than about 0.05% of aluminum
- from about 0% to less than about 0.035% of phosphorus,
- and optionally one or more elements selected from vanadium, niobium and titanium in a total concentration of not more than about 0.85%, balance iron and production-related impurities,
- (b) subjecting the semi-finished product to intensified cooling,
- (c) working the cooled semi-finished product at a temperature of below about 600° C. with a deformation degree of from about 10% to about 20%;
- and
- (d) subjecting the semi-finished product of (c) to a process which comprises machining.
A component for use in oil field technology, wherein the component comprises a drilling string part and is made of a material which comprises an austenitic, substantially ferrite-free steel alloy comprising, in % by weight:
- from about 0% to about 0.35% of carbon
- from about 0% to about 0.75% of silicon
- from more than about 20.0% to about 30.0% of manganese
- from more than about 17.0% to about 24.0% of chromium
- from more than 1.90% to about 5.5% of molybdenum
- from about 0% to about 2.0% of tungsten
- from 3.6% to about 15.0% of nickel
- from about 0% to about 5.0% of cobalt
- from 0.60% to about 1.05% of nitrogen
- from about 0% to about 0.005% of boron
- from about 0% to about 0.30% of sulfur
- from about 0% to less than about 0.5% of copper
- from about 0% to less than about 0.05% of aluminum
- from about 0% to less than about 0.035% of phosphorus,
- and optionally one or more elements selected from vanadium, niobium and titanium in a total concentration of not more than about 0.85%, balance iron and production-related impurities, and wherein the alloy has been hot worked at a temperature of higher than about 750° C., solution-annealed and subsequently worked at a temperature below a recrystallization temperature.
Dependencies are inferred from the claim text.