EP1538232B1 - Corrosion resistant austenitic steel - Google Patents
Corrosion resistant austenitic steel Download PDFInfo
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- EP1538232B1 EP1538232B1 EP04450211A EP04450211A EP1538232B1 EP 1538232 B1 EP1538232 B1 EP 1538232B1 EP 04450211 A EP04450211 A EP 04450211A EP 04450211 A EP04450211 A EP 04450211A EP 1538232 B1 EP1538232 B1 EP 1538232B1
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- 238000005260 corrosion Methods 0.000 title description 51
- 230000007797 corrosion Effects 0.000 title description 51
- 229910000831 Steel Inorganic materials 0.000 title description 6
- 239000010959 steel Substances 0.000 title description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims abstract description 52
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 48
- 229910000851 Alloy steel Inorganic materials 0.000 claims abstract description 44
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 25
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 25
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 25
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000011733 molybdenum Substances 0.000 claims abstract description 23
- 239000011651 chromium Substances 0.000 claims abstract description 18
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 15
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 13
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 11
- 239000010703 silicon Substances 0.000 claims abstract description 11
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 11
- 239000010937 tungsten Substances 0.000 claims abstract description 11
- 239000011572 manganese Substances 0.000 claims abstract description 10
- 238000004519 manufacturing process Methods 0.000 claims abstract description 10
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 7
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000010941 cobalt Substances 0.000 claims abstract description 7
- 229910017052 cobalt Inorganic materials 0.000 claims abstract description 7
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims abstract description 7
- 239000010949 copper Substances 0.000 claims abstract description 7
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 7
- 239000011574 phosphorus Substances 0.000 claims abstract description 7
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052802 copper Inorganic materials 0.000 claims abstract description 6
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 5
- 229910052796 boron Inorganic materials 0.000 claims abstract description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 4
- 239000000463 material Substances 0.000 claims description 23
- 239000011265 semifinished product Substances 0.000 claims description 12
- 238000005516 engineering process Methods 0.000 claims description 8
- 238000003754 machining Methods 0.000 claims description 8
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims description 7
- 229910052748 manganese Inorganic materials 0.000 claims description 7
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 7
- 239000002244 precipitate Substances 0.000 claims description 7
- 238000005553 drilling Methods 0.000 claims description 5
- 239000010955 niobium Substances 0.000 claims description 5
- 239000010936 titanium Substances 0.000 claims description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 238000005266 casting Methods 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 4
- 238000001953 recrystallisation Methods 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 238000007514 turning Methods 0.000 claims description 4
- LEONUFNNVUYDNQ-UHFFFAOYSA-N vanadium atom Chemical compound [V] LEONUFNNVUYDNQ-UHFFFAOYSA-N 0.000 claims description 4
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 239000011780 sodium chloride Substances 0.000 claims description 3
- 229910052720 vanadium Inorganic materials 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 238000000137 annealing Methods 0.000 claims description 2
- 238000000265 homogenisation Methods 0.000 claims description 2
- 239000007788 liquid Substances 0.000 claims description 2
- 238000011068 loading method Methods 0.000 claims description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims 4
- 239000005864 Sulphur Substances 0.000 claims 3
- 239000004411 aluminium Substances 0.000 claims 2
- 239000012535 impurity Substances 0.000 claims 2
- 229910052742 iron Inorganic materials 0.000 claims 2
- PULIYLGUUXFTAS-UHFFFAOYSA-N [Ti].[Nb].[V] Chemical compound [Ti].[Nb].[V] PULIYLGUUXFTAS-UHFFFAOYSA-N 0.000 claims 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 abstract description 4
- 229910052717 sulfur Inorganic materials 0.000 abstract description 4
- 239000011593 sulfur Substances 0.000 abstract description 4
- 229910045601 alloy Inorganic materials 0.000 description 55
- 239000000956 alloy Substances 0.000 description 55
- 238000005336 cracking Methods 0.000 description 13
- 230000002349 favourable effect Effects 0.000 description 11
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 7
- 230000015572 biosynthetic process Effects 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 238000007711 solidification Methods 0.000 description 6
- 230000008023 solidification Effects 0.000 description 6
- 239000000203 mixture Substances 0.000 description 5
- 230000035699 permeability Effects 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 229910001566 austenite Inorganic materials 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 239000011148 porous material Substances 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 229910000859 α-Fe Inorganic materials 0.000 description 4
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 239000000523 sample Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 2
- 229910003296 Ni-Mo Inorganic materials 0.000 description 2
- 230000002411 adverse Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 239000001257 hydrogen Substances 0.000 description 2
- 150000001247 metal acetylides Chemical class 0.000 description 2
- 150000004767 nitrides Chemical class 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- UTPYTEWRMXITIN-YDWXAUTNSA-N 1-methyl-3-[(e)-[(3e)-3-(methylcarbamothioylhydrazinylidene)butan-2-ylidene]amino]thiourea Chemical compound CNC(=S)N\N=C(/C)\C(\C)=N\NC(=S)NC UTPYTEWRMXITIN-YDWXAUTNSA-N 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N ferric oxide Chemical compound O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 229910000037 hydrogen sulfide Inorganic materials 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- 229910001004 magnetic alloy Inorganic materials 0.000 description 1
- 229910000734 martensite Inorganic materials 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 238000002161 passivation Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000013535 sea water Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/58—Ferrous alloys, e.g. steel alloys containing chromium with nickel with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
- C21D8/065—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires of ferrous alloys
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/06—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of rods or wires
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D2261/00—Machining or cutting being involved
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/002—Heat treatment of ferrous alloys containing Cr
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/005—Heat treatment of ferrous alloys containing Mn
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D7/00—Modifying the physical properties of iron or steel by deformation
Definitions
- the invention relates to an austenitic, substantially ferrite-free steel alloy.
- the invention comprises the use of an austenitic, substantially ferrite-free steel alloy.
- the invention relates to a process for the production of austenitic, substantially ferrite-free components, in particular boring bars, for oil field technology.
- Austenitic alloys may be essentially ferrite-free, that is to say with a relative magnetic permeability ⁇ r smaller than 1.01. Thus, austenitic alloys can meet the above requirement and therefore be used principally for drill string components.
- a selected austenitic material reaches minimum mechanical properties, in particular 0.2% proof strength and tensile strength and has grown during drilling operation dynamically changing loads, so in addition has a high fatigue strength. Otherwise, for example, boring bars of corresponding alloys can not withstand the high tensile and compressive stresses and torsional stresses occurring during use, or only for a short service life; undesirable rapid or premature material failure is the result.
- Austenitic materials for drill string components are typically high alloyed with nitrogen to achieve high levels of yield strength and tensile strength of components such as drill rods.
- a requirement to be considered is a lack of pores of the material used, which can be influenced by alloy composition and manufacturing process.
- alloys are economically favorable alloys which lead to non-porous semi-finished product under solidification under atmospheric pressure.
- austenitic alloys are rather rare because of the high nitrogen content, and solidification under elevated pressure is required throughout to achieve freedom from pores. Melting and solidification under nitrogen pressure may also be necessary to obtain enough nitrogen in the solidified material if insufficient nitrogen solubility is otherwise present.
- austenitic alloys intended for use as components of drill strings should have good resistance to various types of corrosion.
- high resistance to pitting corrosion and stress corrosion cracking is desirable, especially in chloride containing media.
- austenitic alloys are known, each of which meets some of these requirements, namely extensive freedom from ferrite, good mechanical properties, freedom from pores and high corrosion resistance.
- An austenitic alloy which leads to objects with low magnetic permeability and good mechanical properties when melted under atmospheric pressure is described in AT 407 882 B.
- Such an alloy has in particular a high 0.2% proof stress, high tensile strength and a high permanent fatigue strength.
- Alloys according to AT 407 882 B are expediently thermoformed and at temperatures of 350 ° C. subjected to a second deformation to about 600 ° C.
- the alloys are suitable for the production of boring bars, which in the context of a drill bit in oilfield technology also satisfactorily meet the high demands with regard to static and dynamic load capacity over long periods of use.
- the invention of the invention and has set itself the task of specifying an austenitic steel alloy which can be melted at atmospheric pressure and porenrud semi-finished and which with good mechanical properties, especially at high 0.2% proof stress, high tensile strength and high fatigue strength, at the same time a high resistance has both against stress corrosion cracking and pitting corrosion.
- Another object of the invention is to provide uses for an austenitic, substantially ferrite-free alloy.
- an austenitic, substantially ferrite-free steel alloy is provided, which has good mechanical properties, in particular high values of 0.2% proof stress and tensile strength and which simultaneously has a high resistance to stress corrosion cracking and also to Pitting corrosion has.
- an at least largely pore-free block of an alloy according to the invention can thus be produced on melting and solidification under atmospheric pressure.
- a temperature below the recrystallization temperature preferably below 600 ° C, in particular in the range of 300 ° C to 550 ° C.
- Carbon (C) may be present in a steel alloy of the invention at levels up to 0.35% by weight. Carbon is an austenite former and has a favorable effect in terms of high mechanical properties. With a view to avoiding carbide precipitations, in particular for larger dimensions, it is preferable to adjust the carbon content to 0.01% by weight to 0.06% by weight.
- Silicon (Si) is provided in amounts up to 0.75% by weight and serves mainly to deoxidize the steel. Higher contents than 0.75% by weight prove to be disadvantageous in terms of formation of intermetallic phases. Moreover, silicon is a ferrite former and therefore a silicon content should be limited to a maximum of 0.75% by weight. It is favorable, and therefore preferred, to provide silicon in contents of from 0.15% by weight to 0.30% by weight, because in this content range a sufficient deoxidizing effect is given with a small contribution of silicon to ferrite formation.
- Manganese (Mn) is provided at levels of greater than 19.0% by weight to 30.0% by weight. This element contributes significantly to high nitrogen solubility. Non-porous materials from an inventive Steel alloy can therefore be produced even under solidification under atmospheric pressure. With respect to a nitrogen solubility of an alloy in the molten state and during and after solidification, it is preferred to use manganese in contents of more than 20% by weight. Manganese also stabilizes the austenite structure, especially at high degrees of deformation, against the formation of deformed martensite. With regard to a preferably good corrosion resistance, an upper limit of the manganese content has been found to be 25.5% by weight.
- Chromium (Cr) proves to be high in corrosion resistance at levels of 17.0% by weight or more.
- chromium allows Zulegieren large amounts of nitrogen.
- Higher contents than 24.0 wt .-% can adversely affect a magnetic permeability, because chromium is one of the ferrite-stabilizing elements.
- Molybdenum (Mo) is an element which contributes substantially to corrosion resistance in general and to pitting corrosion resistance in particular in a steel alloy according to the invention, wherein the effect of molybdenum in a content range of more than 1.90 wt% is enhanced by a presence of nickel ,
- An optimal and therefore preferred range of molybdenum content in terms of corrosion resistance is defined by a lower limit of 2.05% by weight, a particularly preferred range by a lower limit of 2.5% by weight.
- molybdenum on the one hand is an expensive element and on the other hand increases the tendency to form intermetallic phases at higher levels, a molybdenum content of 5.5 wt .-%, in preferred variants of the invention with 5.0 wt .-%, in particular 4.5 wt. %, limited.
- Nickel (Ni) has been found to contribute actively and positively to corrosion resistance in a content range greater than 2.50% to 15.0% by weight and in cooperation with the other alloying elements. In particular, and this is considered to be completely surprising from a professional point of view, in the presence of more than 2.50 wt .-% nickel is given a high stress corrosion cracking resistance. Contrary to the opinion outlined in relevant textbooks, with increasing nickel levels, stress corrosion cracking resistance of chromium-containing austenites in chloride-containing media decreases dramatically and is at a minimum at about 20 wt% (see, eg: AJ Sedriks, Corrosion of Stainless Steels, 2 ed. , John Wiley & Sons Inc., 1996, page 276), a high stress crack corrosion resistance can be achieved in a steel alloy according to the invention even with nickel contents of more than 2.50% to 15.0% by weight in chloride-containing media.
- Nickel contents of at least 2.65% by weight, preferably at least 3.6% by weight, in particular 3.8% by weight to 9.8% by weight, of nickel are particularly preferred in this connection.
- Co Co
- Co may be present at levels up to 5.0% by weight for substitution of nickel. Preferably, however, it is because of the high cost of this element due to keep a cobalt content below 0.2 wt .-%.
- Nickel as stated above, makes a high contribution to corrosion resistance and is a strong austenite former.
- molybdenum also makes a significant contribution to corrosion resistance, but is a ferrite former. Therefore, it is favorable if the nickel content is equal to or greater than the molybdenum content. In this context, it is particularly favorable if a nickel content is more than 1.3 times, preferably more than 1.5 times, a molybdenum content.
- Nitrogen (N) is required in amounts of at least 0.35 wt% to 1.05 wt% to ensure high strength. Further, nitrogen contributes to the corrosion resistance and is a strong austenite former, therefore, higher contents than 0.40 wt .-%, especially higher than 0.60 wt .-%, are favorable. On the other hand, as nitrogen content increases, nitrogen-containing precipitate formation tends to increase, for example, Cr 2 N. In advantageous variants of the invention, nitrogen content is therefore limited to 0.95% by weight, preferably 0.90% by weight.
- Boron (B) can be provided in amounts of up to 0.005% by weight and, in particular in a range from 0.0005% by weight to 0.004% by weight, promotes hot workability of the material composed according to the invention.
- Copper (Cu) is tolerable in a steel alloy according to the invention in a content of less than 0.5 wt .-%. At levels of 0.04 wt.% To 0.35 wt.%, Copper proves to be quite advantageous in special drill bit applications, for example when boring bars come in contact with media such as hydrogen sulfide, especially H 2 S. Contents higher than 0.5% by weight promote precipitation formation and are disadvantageous for corrosion resistance.
- Aluminum (Al) contributes to deoxidation of the steel besides silicon, but is a strong nitride former, which limits this element to less than 0.05% by weight.
- S Sulfur
- S is provided at levels up to 0.30% by weight. Greater contents than 0.1% by weight have a very favorable effect on the processing of a steel alloy according to the invention, because machining is facilitated. However, if one considers the highest corrosion resistance of the material, a sulfur content of 0.015 wt .-% is limited.
- the content of phosphorus (P) is less than 0.035% by weight.
- a phosphorus content is limited to a maximum of 0.02 wt .-%.
- Vanadium (V), niobium (Nb), titanium (Ti) act in a complementary manner in the steel and can be present for this purpose individually or in any desired combination, with a maximum concentration of the elements present being at most 0.85% by weight. In view of a grain-refining effect and avoidance of coarse precipitations of these strong carbide formers, it is beneficial if a sum concentration of the elements present is more than 0.08% by weight and less than 0.45% by weight.
- the elements tungsten, molybdenum, manganese, chromium, vanadium, niobium and titanium contribute positively to the solubility of nitrogen.
- the further object of the invention to provide uses for an austenitic, substantially ferrite-free alloy is achieved by using a steel alloy according to the invention as a material for components for oil field technology.
- a steel alloy according to the invention as a material for components for oil field technology.
- the component is a Bohrstrangteil.
- the further object of the invention is also achieved by using an alloy according to the invention for tensile and compression stressed components, which come into contact with corrosive media, in particular a corrosive liquid such as saline water.
- the method of the invention is achieved by a method according to claim 26.
- the semifinished product is expediently a bar which is deformed in the second deformation step with a degree of deformation of 10% to 20%.
- Such degrees of deformation provide sufficient strength for use and permit turning or peeling machining with reduced tool wear.
- Rapid and cost effective component manufacturing is enabled when the machining involves turning and / or peeling.
- blocks were prepared whose chemical compositions correspond to alloys 1 to 5 and 7 in Table 1.
- An alloy 6 cast in Table 1 was remelted under nitrogen atmosphere at 16 bar pressure and stitched.
- the semifinished blocks were quenched with water to ambient temperature and finally subjected to a second deformation step at a temperature of 380 ° C to 420 ° C, with a degree of deformation of 13% to 17%.
- the objects created in this way were examined or further processed into boring bars.
- Alloys A, B, C, D and E represent products available on the market.
- the alloys listed in Table 1 were examined for pitting corrosion resistance and stress corrosion cracking.
- the determination of the pitting corrosion resistance was carried out by measuring the pitting potential against a standard hydrogen electrode according to ASTM G 61.
- the stress corrosion cracking (SCC) was determined by determining the value of the SCC limit stress according to ATSM G 36.
- the value of the SCC cut-off voltage represents the externally applied maximum test voltage which a test sample can withstand for more than 720 hours in 155% boiling 45% MgCl 2 solution.
- Pitting potential E pit or SCC limit stress can even reach values corresponding to those of high alloyed Cr-Ni-Mo steels and nickel base alloys, with better strength properties as shown in Tables 4 and 5 at the same time. It is particularly favorable with respect to an SCC limit voltage, if a sum of molybdenum and nickel 4.7 wt .-% or more, in particular more than 6 wt .-%, is.
- articles made of the alloys 1 to 7 according to the invention have a relative magnetic permeability of ⁇ r ⁇ 1,005 and at room temperature permanent fatigue strengths of at least 400 MPa at 10 7 load changes.
- indexable inserts could be used 12% longer when machining Alloys 3 and 4 than when machining Alloy C rods Boring bars, which have high mechanical characteristics and improved corrosion resistance, are produced with less tool wear.
- an alloy according to the invention is also optimally suitable as a material for fastening or connecting elements, such as Screws, nails, bolts or similar components, if they are exposed to high mechanical loads and aggressive environmental conditions.
- alloys according to the invention find advantageous use is in the field of corrosion and wear parts such as baffles or parts that are exposed to high loading speeds.
- components of alloys of the invention due to their combination of properties lowest material wear and thus achieve maximum life.
Abstract
Description
Die Erfindung betrifft eine austenitische, im Wesentlichen ferritfreie Stahllegierung.The invention relates to an austenitic, substantially ferrite-free steel alloy.
Weiter umfasst die Erfindung die Verwendung einer austenitischen, im Wesentlichen ferritfreien Stahllegierung.Furthermore, the invention comprises the use of an austenitic, substantially ferrite-free steel alloy.
Schließlich bezieht sich die Erfindung auf ein Verfahren zur Herstellung von austenitischen, im Wesentlichen ferritfreien Komponenten, insbesondere Bohrstangen, für die Ölfeldtechnik.Finally, the invention relates to a process for the production of austenitic, substantially ferrite-free components, in particular boring bars, for oil field technology.
Beim Niederbringen von Bohrungen, beispielsweise in der Ölfeldtechnik, ist es notwendig, einen Bohrlochverlauf möglichst exakt festzustellen. Dies erfolgt üblicherweise durch Bestimmung der Lage des Bohrkopfes mit Hilfe von Magnetfeldsonden, bei welchen das magnetische Feld der Erde zur Messung genutzt wird. Teile von Bohrgeräten, insbesondere Bohrstangen, sind deswegen aus nicht-magnetischen Legierungen gefertigt. In diesem Zusammenhang wird heute zumindest für die in unmittelbarer Nähe von Magnetfeldsonden befindlichen Teile von Bohrsträngen eine relative magnetische Permeabilität µr kleiner als 1.01 gefordert.When drilling holes, for example in oil field technology, it is necessary to determine a course of the bore hole as accurately as possible. This is usually done by determining the position of the drill head by means of magnetic field probes, in which the magnetic field of the earth is used for the measurement. Parts of drills, especially boring bars, are therefore made of non-magnetic alloys. In this context, a relative magnetic permeability μ r less than 1.01 is required today at least for the parts of drill strings located in the immediate vicinity of magnetic field probes.
Austenitische Legierungen können im Wesentlichen ferritfrei, das heißt mit einer relativen magnetischen Permeabilität µr kleiner als 1.01, ausgebildet sein. Somit können austenitische Legierungen die vorstehende Forderung erfüllen und daher grundsätzlich für Bohrstrangkomponenten eingesetzt werden.Austenitic alloys may be essentially ferrite-free, that is to say with a relative magnetic permeability μ r smaller than 1.01. Thus, austenitic alloys can meet the above requirement and therefore be used principally for drill string components.
Um für einen Einsatz in der Form von Bohrstrangkomponenten insbesondere für Tieflochbohrungen geeignet zu sein, ist es weiter erforderlich, dass ein gewählter austenitischer Werkstoff Mindestwerte der mechanischen Eigenschaften, insbesondere der 0.2 %-Dehngrenze und Zugfestigkeit, erreicht und den beim Bohrbetrieb auftretenden dynamisch wechselnden Belastungen gewachsen ist, also zusätzlich eine hohe Dauerwechselfestigkeit aufweist. Andernfalls können beispielsweise Bohrstangen aus entsprechenden Legierungen den beim Gebrauch auftretenden hohen Zug- und Druckbeanspruchungen sowie Torsionsbeanspruchungen nicht oder nur für eine kurze Einsatzzeit standhalten; unerwünscht rasches bzw. vorzeitiges Materialversagen ist die Folge.In order to be suitable for use in the form of drill string components, in particular for deep hole drilling, it is further required that a selected austenitic material reaches minimum mechanical properties, in particular 0.2% proof strength and tensile strength and has grown during drilling operation dynamically changing loads, so in addition has a high fatigue strength. Otherwise, for example, boring bars of corresponding alloys can not withstand the high tensile and compressive stresses and torsional stresses occurring during use, or only for a short service life; undesirable rapid or premature material failure is the result.
Austenitische Werkstoffe für Bohrstrangkomponenten werden in der Regel hoch mit Stickstoff legiert, um hohe Werte der Streckgrenze und der Zugfestigkeit von Komponenten wie Bohrstangen zu erreichen. Eine zu berücksichtigende Anforderung ist jedoch eine Porenfreiheit des eingesetzten Werkstoffes, welche durch Legierungszusammensetzung und Herstellverfahren beeinflussbar ist.Austenitic materials for drill string components are typically high alloyed with nitrogen to achieve high levels of yield strength and tensile strength of components such as drill rods. However, a requirement to be considered is a lack of pores of the material used, which can be influenced by alloy composition and manufacturing process.
In diesem Bezug stellen sich wirtschaftlich günstig selbstredend Legierungen dar, welche bei Erstarrung unter Atmosphärendruck zu porenfreiem Halbzeug führen. In der Praxis sind solche austenitische Legierungen allerdings des hohen Stickstoffgehaltes wegen eher selten, und es ist durchwegs ein Erstarren unter erhöhtem Druck erforderlich, um eine Porenfreiheit zu erreichen. Ein Erschmelzen und Erstarren unter Stickstoffdruck kann auch notwendig sein, um genügend Stickstoff im erstarrten Material zu erhalten, wenn andernfalls eine unzureichende Stickstofflöslichkeit gegeben ist.Of course, in this regard, alloys are economically favorable alloys which lead to non-porous semi-finished product under solidification under atmospheric pressure. In practice, however, such austenitic alloys are rather rare because of the high nitrogen content, and solidification under elevated pressure is required throughout to achieve freedom from pores. Melting and solidification under nitrogen pressure may also be necessary to obtain enough nitrogen in the solidified material if insufficient nitrogen solubility is otherwise present.
Schließlich sollten austenitische Legierungen, welche für einen Einsatz als Komponenten von Bohrsträngen vorgesehen sind, eine gute Beständigkeit gegen verschiedene Arten von Korrosion aufweisen. Insbesondere ist ein hoher Widerstand gegen Lochfraßkorrosion und Spannungsrisskorrosion vor allem in chloridhältigen Medien erwünscht.Finally, austenitic alloys intended for use as components of drill strings should have good resistance to various types of corrosion. In particular, high resistance to pitting corrosion and stress corrosion cracking is desirable, especially in chloride containing media.
Gemäß dem Stand der Technik sind austenitische Legierungen bekannt, welche jeweils einige dieser Anforderungen, nämlich weitgehende Ferritfreiheit, gute mechanische Eigenschaften, Porenfreiheit und hohe Korrosionsbeständigkeit, erfüllen.According to the prior art, austenitic alloys are known, each of which meets some of these requirements, namely extensive freedom from ferrite, good mechanical properties, freedom from pores and high corrosion resistance.
Aus der DE 39 40 438 C1 sind Gegenstände aus einem warm- und kaltverformten und nachfolgend bei Temperaturen von über 300 °C ausgelagerten, austenitischen Werkstoff mit (in Gewichtsprozent) max. 0.12 % Kohlenstoff, 0.20 % bis 1.00 % Silicium, 17.5 % bis 20.0 % Mangan, maximal 0.05 % Phosphor, maximal 0.015 % Schwefel, 17.0 % bis 20.0 % Chrom, maximal 5 % Molybdän, maximal 3.0 % Nickel, 0.8 % bis 1.2 % Stickstoff, bekannt. Diese Gegenstände weisen allerdings, wie in der DE 196 07 828 A1 von einigen derselben Erfinder bemerkt wird, bescheidene Dauerwechselfestigkeiten von bestenfalls 375 MPa auf, welche in aggressiver Umgebung, z.B. in Salzlösung noch deutlich tiefer liegen.From DE 39 40 438 C1 are articles of a hot and cold-formed and subsequently outsourced at temperatures of about 300 ° C, austenitic material with (in weight percent) max. 0.12% carbon, 0.20% to 1.00% silicon, 17.5% to 20.0% manganese, maximum 0.05% phosphorus, maximum 0.015% sulfur, 17.0% to 20.0% chromium, maximum 5% molybdenum, maximum 3.0% nickel, 0.8% to 1.2% Nitrogen, known. However, these objects, as noted in DE 196 07 828 A1 by some of the same inventors, have modest fatigue strengths of at best 375 MPa, which in an aggressive environment, e.g. in saline even lower.
Eine andere austenitische Legierung ist aus der nebenbei schon erwähnten DE 196 07 828 A1 bekannt. Gemäß dieser Schrift werden Gegenstände für die offshore-Industrie vorgeschlagen, die aus einer austenitischen Legierung mit (in Gewichtsprozent) 0.1 % Kohlenstoff, 8 % bis 15 % Mangan, 13 % bis 18 % Chrom, 2.5 % bis 6 % Molybdän, 0 % bis 5 % Nickel und 0.55 % bis 1.1 % Stickstoff bestehen. Derartige Gegenstände sollen hohe mechanische Kennwerte und eine höhere Dauerwechselwechselfestigkeit als Gegenstände nach der DE 39 40 438 C1 aufweisen. Nachteilig ist jedoch eine auf die Legierungszusammensetzung zurückführbare geringe Stickstofflöslichkeit, weshalb unter Druck geschmolzen und erstarren gelassen werden muss oder noch aufwändigere pulvermetallurgische Herstellverfahren anzuwenden sind.Another austenitic alloy is known from the incidentally already mentioned DE 196 07 828 A1. According to this document, articles are proposed for the offshore industry consisting of an austenitic alloy containing (in weight percent) 0.1% carbon, 8% to 15% manganese, 13% to 18% chromium, 2.5% to 6% molybdenum, 0% to 5% nickel and 0.55% to 1.1% nitrogen. Such articles should have high mechanical properties and a higher permanent alternating fatigue strength than articles according to DE 39 40 438 C1. A disadvantage, however, is a low nitrogen solubility attributable to the alloy composition, which is why it is necessary to melt and solidify under pressure or to use more complex powder metallurgical production processes.
Eine bei Erschmelzen unter Atmosphärendruck zu Gegenständen mit geringer magnetischer Permeabilität und guten mechanischen Eigenschaften führende austenitische Legierung ist in der AT 407 882 B beschrieben. Eine solche Legierung weist insbesondere eine hohe 0.2 % Dehngrenze, hohe Zugfestigkeit und eine hohe Dauerwechselfestigkeit auf. Legierungen gemäß der AT 407 882 B werden zweckmäßigerweise warmverformt und bei Temperaturen von 350°C bis etwa 600°C einer zweiten Verformung unterworfen. Die Legierungen eigenen sich für eine Herstellung von Bohrstangen, welche im Rahmen eines Bohreinsatzes in der Ölfeldtechnik auch den hohen Anforderungen hinsichtlich statischer und dynamischer Belastbarkeit über lange Einsatzzeiten in zufriedenstellender Weise Rechnung tragen.An austenitic alloy which leads to objects with low magnetic permeability and good mechanical properties when melted under atmospheric pressure is described in AT 407 882 B. Such an alloy has in particular a high 0.2% proof stress, high tensile strength and a high permanent fatigue strength. Alloys according to AT 407 882 B are expediently thermoformed and at temperatures of 350 ° C. subjected to a second deformation to about 600 ° C. The alloys are suitable for the production of boring bars, which in the context of a drill bit in oilfield technology also satisfactorily meet the high demands with regard to static and dynamic load capacity over long periods of use.
Dennoch, so wurde festgestellt, kann es zu Materialversagen kommen, weil Bohrstrangkomponenten wie Bohrstangen bei einem Einsatz neben hohen mechanischen Beanspruchungen auch hochkorrosiven Medien bei erhöhten Temperaturen ausgesetzt sind. In der Folge kann es zu Spannungsrisskorrosion kommen. Da Bohrstangen und andere Teile von Bohreinrichtungen auch während Stehzeiten mit korrosiven Medien in Kontakt stehen können, kann Lochfraßkorrosion ebenfalls entscheidend zum Materialversagen beitragen. Beide Korrosionsarten bewirken in der Praxis eine Verkürzung der maximalen theoretischen Gebrauchsdauer bzw. der Einsatzzeit von Bohrstangen, wie sie auf Grund der mechanischen Eigenschaften bzw. Kennwerte zu erwarten wäre.Nevertheless, it has been found that material failure can occur because drill string components such as boring bars are subject to high corrosive media at elevated temperatures when used in addition to high mechanical stresses. As a result, stress corrosion cracking can occur. Since boring bars and other parts of drilling equipment can also be in contact with corrosive media during downtime, pitting corrosion can also contribute significantly to material failure. Both types of corrosion cause in practice a reduction of the maximum theoretical service life or the service life of drill rods, as would be expected on the basis of mechanical properties or characteristic values.
Gemäß dem dargelegten Stand der Technik zeigt sich, dass bei hochstickstoffhältigen austenitischen Legierungen, welche unter Atmosphärendruck zu zumindest weitgehend porenfreien Blöcken erschmelzbar sind, die Anforderungen hinsichtlich guter mechanischer Eigenschaften und gleichzeitig hoher Beständigkeit gegen Korrosion bei Zug- und Druckbelastung als auch gegen Lochfraßkorrosion nicht zufriedenstellend erfüllt sind.According to the prior art set out, it is found that high nitrogen-containing austenitic alloys that can be melted under atmospheric pressure to at least largely non-porous blocks satisfies the requirements for good mechanical properties and at the same time high resistance to corrosion under tensile and compressive stress as well as pitting corrosion are.
Hier knüpft die Erfindung an und stellt sich zur Aufgabe, eine austenitische Stahllegierung anzugeben, welche bei Atmosphärendruck erschmelzbar und zu porenfreiem Halbzeug verarbeitbar ist und welche bei guten mechanischen Eigenschaften, insbesondere bei hoher 0.2 % Dehngrenze, hoher Zugfestigkeit und hoher Dauerwechselfestigkeit, gleichzeitig eine hohe Beständigkeit sowohl gegen Spannungsrisskorrosion als auch gegen Lochfraßkorrosion aufweist.Here, the invention of the invention and has set itself the task of specifying an austenitic steel alloy which can be melted at atmospheric pressure and porenfreien semi-finished and which with good mechanical properties, especially at high 0.2% proof stress, high tensile strength and high fatigue strength, at the same time a high resistance has both against stress corrosion cracking and pitting corrosion.
Ein weiteres Ziel der Erfindung ist es, Verwendungen für eine austenitische, im Wesentlichen ferritfreie Legierung anzugeben.Another object of the invention is to provide uses for an austenitic, substantially ferrite-free alloy.
Die genannte Aufgabe löst eine Stahllegierung nach Anspruch 1. Vorteilhafte Weiterbildungen einer erfindungsgemäßen Stahllegierung sind Gegenstand der Ansprüche 2 bis 21.The object mentioned solves a steel alloy according to claim 1. Advantageous developments of a steel alloy according to the invention are the subject matter of claims 2 to 21.
Die mit der Erfindung erzielten Vorteile sind insbesondere darin zu sehen, dass eine austenitische, im Wesentlichen ferritfreie Stahllegierung bereitgestellt wird, welche gute mechanische Eigenschaften, insbesondere hohe Werte der 0.2 % Dehngrenze und der Zugfestigkeit aufweist und welche gleichzeitig eine hohe Beständigkeit gegen Spannungsrisskorrosion und auch gegen Lochfraßkorrosion aufweist.The advantages achieved by the invention are in particular to be seen in that an austenitic, substantially ferrite-free steel alloy is provided, which has good mechanical properties, in particular high values of 0.2% proof stress and tensile strength and which simultaneously has a high resistance to stress corrosion cracking and also to Pitting corrosion has.
Auf Grund einer synergetisch abgestimmten Legierungszusammensetzung ist eine hohe Stickstofflöslichkeit gegeben. In vorteilhafter Weise kann somit ein zumindest weitgehend porenfreier Block aus einer erfindungsgemäßen Legierung bei Schmelzen und Erstarren unter Atmosphärendruck erstellt werden.Due to a synergically matched alloy composition, a high nitrogen solubility is given. In an advantageous manner, an at least largely pore-free block of an alloy according to the invention can thus be produced on melting and solidification under atmospheric pressure.
Nach einer Warmverformung eines Gussstückes in einem oder mehreren Schritten, einem wahlweise darauffolgenden Lösungsglühen des Halbzeuges und einer danach folgenden weiteren Verformung bei einer Temperatur unterhalb der Rekristallisationstemperatur, vorzugsweise unterhalb von 600 °C, insbesondere im Bereich von 300 °C bis 550 °C, liegt ein erfindungsgemäß zusammengesetzter Werkstoff im Wesentlichen frei von stickstoffhältigen und/oder karbidischen Ausscheidungen vor. Dies bewirkt eine hohe Dauerwechselfestigkeit desselben, weil der gesamte Stickstoff in Lösung vorliegt und beispielsweise Karbide, welche als Mikrokerben wirken, stark reduziert sind. Dementsprechend weist ein Gegenstand aus der erfindungsgemäßen Legierung bei Raumtemperatur eine Dauerwechselfestigkeit von mehr als 400 MPa bei 107 Lastwechsel auf.After a hot deformation of a casting in one or more steps, an optional subsequent solution heat treatment of the semifinished product and subsequent further deformation at a temperature below the recrystallization temperature, preferably below 600 ° C, in particular in the range of 300 ° C to 550 ° C. an inventively composed material substantially free of nitrogen-containing and / or carbide precipitates before. This causes a high permanent fatigue strength of the same, because the entire nitrogen is in solution and, for example, carbides, which act as micro-scores are greatly reduced. Accordingly, an article of the alloy according to the invention at room temperature has a permanent fatigue strength of more than 400 MPa at 10 7 load changes.
Andererseits bewirkt eine Freiheit von stickstoffhältigen und/oder karbidischen Ausscheidungen allgemein eine hohe Korrosionsbeständigkeit des Stahls, weil vor allem Chrom und Molybdän nicht als Karbide bzw. Nitride gebunden sind und daher in Bezug auf Korrosionsbeständigkeit ihre passivierende Wirkung vollflächig entfalten. So können Teile aus erfindungsgemäßen Stahllegierungen bei besseren mechanischen Eigenschaften Beständigkeiten gegen Spannungsrisskorrosion und Lochfraßkorrosion aufweisen, die jene von hochlegierten Cr-Ni-Mo-Austeniten übertreffen.On the other hand, a freedom of nitrogen-containing and / or carbide precipitates generally high corrosion resistance of the steel, because especially chromium and molybdenum are not bound as carbides or nitrides and therefore develop their passivation effect over the entire surface in terms of corrosion resistance. Thus, parts of steel alloys according to the invention, with better mechanical properties, can have resistance to stress corrosion cracking and pitting corrosion, which exceed those of high-alloy Cr-Ni-Mo austenites.
Im Folgenden sind die Wirkungen der jeweiligen Elemente einzeln und im Zusammenwirken mit den übrigen Legierungsbestandteilen näher beschrieben.In the following, the effects of the respective elements are described individually and in conjunction with the other alloy constituents.
Kohlenstoff (C) kann in einer erfindungsgemäßen Stahllegierung in Gehalten bis zu 0.35 Gew.-% vorhanden sein. Kohlenstoff ist ein Austenitbildner und wirkt sich in Bezug auf hohe mechanische Kennwerte günstig aus. Im Hinblick auf eine Vermeidung von karbidischen Ausscheidungen, insbesondere bei größeren Dimensionen, ist es bevorzugt, den Kohlenstoffgehalt auf 0.01 Gew.-% bis 0.06 Gew.-% einzustellen.Carbon (C) may be present in a steel alloy of the invention at levels up to 0.35% by weight. Carbon is an austenite former and has a favorable effect in terms of high mechanical properties. With a view to avoiding carbide precipitations, in particular for larger dimensions, it is preferable to adjust the carbon content to 0.01% by weight to 0.06% by weight.
Silicium (Si) ist in Gehalten bis 0.75 Gew.-% vorgesehen und dient in der Hauptsache einer Desoxidation des Stahls. Höhere Gehalte als 0.75 Gew.-% erweisen sich im Hinblick auf eine Ausbildung intermetallischer Phasen als nachteilig. Silicium ist überdies ein Ferritbildner und auch deswegen sollte ein Siliciumgehalt auf maximal 0.75 Gew.-% begrenzt sein. Günstig und daher bevorzugt ist es, Silicium in Gehalten von 0.15 Gew.-% bis 0.30 Gew.-% vorzusehen, weil in diesem Gehaltsbereich eine ausreichend desoxidierende Wirkung bei geringem Beitrag von Silicium zur Ferritbildung gegeben ist.Silicon (Si) is provided in amounts up to 0.75% by weight and serves mainly to deoxidize the steel. Higher contents than 0.75% by weight prove to be disadvantageous in terms of formation of intermetallic phases. Moreover, silicon is a ferrite former and therefore a silicon content should be limited to a maximum of 0.75% by weight. It is favorable, and therefore preferred, to provide silicon in contents of from 0.15% by weight to 0.30% by weight, because in this content range a sufficient deoxidizing effect is given with a small contribution of silicon to ferrite formation.
Mangan (Mn) ist in Gehalten von mehr als 19.0 Gew.-% bis zu 30.0 Gew.-% vorgesehen. Dieses Element trägt wesentlich zu einer hohen Stickstofflöslichkeit bei. Porenfreie Werkstoffe aus einer erfindungsgemäßen Stahllegierung sind deshalb auch bei Erstarren unter Atmosphärendruck herstellbar. Hinsichtlich einer Stickstofflöslichkeit einer Legierung im schmelzflüssigen Zustand sowie während und nach der Erstarrung ist es bevorzugt, Mangan in Gehalten von mehr als 20 Gew.-% einzusetzen. Mangan stabilisiert überdies das Austenitgefüge speziell bei hohen Verformungsgraden gegen die Bildung von Umformmartensit. Mit Bezug auf eine bevorzugt gute Korrosionsbeständigkeit hat sich eine obere Grenze des Mangangehaltes mit 25.5 Gew.-% ergeben.Manganese (Mn) is provided at levels of greater than 19.0% by weight to 30.0% by weight. This element contributes significantly to high nitrogen solubility. Non-porous materials from an inventive Steel alloy can therefore be produced even under solidification under atmospheric pressure. With respect to a nitrogen solubility of an alloy in the molten state and during and after solidification, it is preferred to use manganese in contents of more than 20% by weight. Manganese also stabilizes the austenite structure, especially at high degrees of deformation, against the formation of deformed martensite. With regard to a preferably good corrosion resistance, an upper limit of the manganese content has been found to be 25.5% by weight.
Chrom (Cr) erweist sich in Gehalten von 17.0 Gew.-% oder mehr als notwendig für eine hohe Korrosionsbeständigkeit. Außerdem ermöglicht Chrom ein Zulegieren großer Stickstoffmengen. Höhere Gehalte als 24.0 Gew.-% können sich nachteilig auf eine magnetische Permeabilität auswirken, weil Chrom zu den ferritstabilisierenden Elementen zählt. Besonders vorteilhaft sind Chrom-Gehalte von 19.0 % bis 23.5 %, vorzugsweise 20.0 % bis 23.0 %. Bei diesen Gehalten zeigt eine gemeinsame Betrachtung der Neigung zur Bildung von chromhältigen Ausscheidungen und Beständigkeit gegen Lochfraß- und Spannungsrisskorrosion ein Optimum.Chromium (Cr) proves to be high in corrosion resistance at levels of 17.0% by weight or more. In addition, chromium allows Zulegieren large amounts of nitrogen. Higher contents than 24.0 wt .-% can adversely affect a magnetic permeability, because chromium is one of the ferrite-stabilizing elements. Chromium contents of 19.0% to 23.5%, preferably 20.0% to 23.0%, are particularly advantageous. At these levels, a joint consideration of the tendency to form chromium-containing precipitates and resistance to pitting and stress corrosion cracking shows an optimum.
Molybdän (Mo) ist ein Element, welches in einer Stahllegierung gemäß der Erfindung wesentlich zur Korrosionsbeständigkeit im allgemeinen und zur Lochfraßkorrosionsbeständigkeit im besonderen beiträgt, wobei die Wirkung von Molybdän in einem Gehaltsbereich von mehr als 1.90 Gew.-% durch eine Anwesenheit von Nickel verstärkt wird. Ein optimaler und daher bevorzugter Bereich des Molybdängehaltes in Bezug auf eine Korrosionsbeständigkeit ist durch eine untere Grenze von 2.05 Gew.-%, ein besonders bevorzugter Bereich durch eine untere Grenze von 2.5 Gew.-%, festgelegt. Da Molybdän zum einen ein teures Element ist und zum anderen bei größeren Gehalten die Tendenz zur Bildung intermetallischer Phasen steigt, ist ein Molybdängehalt mit 5.5 Gew.-%, in bevorzugten Varianten der Erfindung mit 5.0 Gew.-%, insbesondere mit 4.5 Gew.-%, begrenzt.Molybdenum (Mo) is an element which contributes substantially to corrosion resistance in general and to pitting corrosion resistance in particular in a steel alloy according to the invention, wherein the effect of molybdenum in a content range of more than 1.90 wt% is enhanced by a presence of nickel , An optimal and therefore preferred range of molybdenum content in terms of corrosion resistance is defined by a lower limit of 2.05% by weight, a particularly preferred range by a lower limit of 2.5% by weight. Since molybdenum on the one hand is an expensive element and on the other hand increases the tendency to form intermetallic phases at higher levels, a molybdenum content of 5.5 wt .-%, in preferred variants of the invention with 5.0 wt .-%, in particular 4.5 wt. %, limited.
Wolfram (W) kann in Konzentrationen von bis zu 2.0 Gew.-% anwesend sein und zur Steigerung der Korrosionsbeständigkeit beitragen. Wenn eine im Wesentlichen ausscheidungsfreie Legierung gefordert ist, ist es zweckmäßig einen Wolframgehalt zwischen 0.05 Gew.-% und 0.2 Gew.-% zu halten. Um intermetallische bzw. stickstoffhältige und/oder karbidische Ausscheidungen von Wolfram bzw. Wolfram und Molybdän hintan zuhalten, ist es günstig, wenn ein Summengehalt X (in Gew.-%) dieser Elemente, berechnet nach X = (%Molybdän) + 0.5*(% Wolfram), größer als 2 und kleiner als 5.5 ist.Tungsten (W) may be present in concentrations up to 2.0% by weight and contribute to increasing corrosion resistance. When a substantially precipitation-free alloy is required, it is desirable to maintain a tungsten content of between 0.05% and 0.2% by weight. In order to prevent intermetallic or nitrogen-containing and / or carbidic precipitations of tungsten or tungsten and molybdenum, it is favorable if a sum content X (in% by weight) of these elements, calculated according to X = (% molybdenum) + 0.5 * ( % Tungsten), greater than 2 and less than 5.5.
Nickel (Ni) trägt, wie gefunden wurde, in einem Gehaltsbereich von mehr als 2.50 Gew.-% bis 15.0 Gew.-% und im Zusammenwirken mit den übrigen Legierungselementen aktiv und positiv zur Korrosionsbeständigkeit bei. Insbesondere, und dies ist aus fachmännischer Sicht als völlig überraschend zu werten, ist bei Anwesenheit von mehr als 2.50 Gew.-% Nickel eine hohe Spannungsrisskorrosionsbeständigkeit gegeben. Entgegen der in einschlägigen Lehr- und Fachbüchem dargelegten Meinung, dass mit steigenden Nickelgehalten die Spannungsrisskorrosionsbeständigkeit von chromhältigen Austeniten in chloridhältigen Medien dramatisch abnimmt und bei etwa 20 Gew.-% ein Minimum einnimmt (siehe, z.B.: A.J. Sedriks, Corrosion of Stainless Steels, 2nd Edition, John Wiley & Sons Inc., 1996, Seite 276), kann in einer erfindungsgemäßen Stahllegierung auch bei Nickelgehalten von mehr als 2.50 Gew.-% bis 15.0 Gew.-% in chloridhältigen Medien eine hohe Spannungsrisskorrosionsbeständigkeit erreicht werden.Nickel (Ni) has been found to contribute actively and positively to corrosion resistance in a content range greater than 2.50% to 15.0% by weight and in cooperation with the other alloying elements. In particular, and this is considered to be completely surprising from a professional point of view, in the presence of more than 2.50 wt .-% nickel is given a high stress corrosion cracking resistance. Contrary to the opinion outlined in relevant textbooks, with increasing nickel levels, stress corrosion cracking resistance of chromium-containing austenites in chloride-containing media decreases dramatically and is at a minimum at about 20 wt% (see, eg: AJ Sedriks, Corrosion of Stainless Steels, 2 ed. , John Wiley & Sons Inc., 1996, page 276), a high stress crack corrosion resistance can be achieved in a steel alloy according to the invention even with nickel contents of more than 2.50% to 15.0% by weight in chloride-containing media.
Eine abgesicherte wissenschaftliche Erklärung dieses Effekts liegt noch nicht vor. Vermutet wird Folgendes: Für eine Entstehung transkristalliner Spannungsrisskorrosion durch Gleitvorgänge ist eine planare Versetzungsanordnung notwendig, welche durch eine niedrige Stapelfehlerenergie begünstigt wird. In einer erfindungsgemäßen Legierung erhöht Nickel die Stapelfehlerenergie. Dies führt bei mehr als 2.50 Gew.-% Nickel zu hohen Stapelfehlerenergien und zu Versetzungsknäuel, wodurch eine Anfälligkeit gegen Spannungsrisskorrosion verringert ist.A reliable scientific explanation of this effect is not yet available. It is believed that the formation of transcrystalline stress corrosion cracking requires a planar dislocation arrangement favored by low stacking fault energy. In an alloy according to the invention, nickel increases the stacking fault energy. This results in high stacking fault energies and dislocation balls at more than 2.50 wt.% Nickel, which reduces susceptibility to stress corrosion cracking.
Besonders bevorzugt sind in diesem Zusammenhang Nickelgehalte von zumindest 2.65 Gew.-%, vorzugsweise zumindest 3.6 Gew.-%, insbesondere 3.8 Gew.-% bis 9.8 Gew.-%, Nickel.Nickel contents of at least 2.65% by weight, preferably at least 3.6% by weight, in particular 3.8% by weight to 9.8% by weight, of nickel are particularly preferred in this connection.
Cobalt (Co) kann in Gehalten bis zu 5.0 Gew.-% zur Substitution von Nickel vorgesehen sein. Bevorzugt ist es jedoch schon der hohen Kosten dieses Elementes wegen, einen Cobaltgehalt unter 0.2 Gew.-% zu halten.Cobalt (Co) may be present at levels up to 5.0% by weight for substitution of nickel. Preferably, however, it is because of the high cost of this element due to keep a cobalt content below 0.2 wt .-%.
Nickel leistet, wie oben dargelegt, einen hohen Beitrag zur Korrosionsbeständigkeit und ist ein starker Austenitbildner. Demgegenüber leistet Molybdän zwar auch einen wesentlichen Beitrag zur Korrosionsbeständigkeit, ist aber ein Ferritbildner. Daher ist es günstig, wenn der Nickelgehalt gleich oder größer ist, als der Molybdängehalt. Besonders günstig ist in diesem Zusammenhang, wenn ein Nickelgehalt mehr als das 1.3-fache, vorzugsweise mehr als das 1.5-fache, eines Molybdängehaltes beträgt.Nickel, as stated above, makes a high contribution to corrosion resistance and is a strong austenite former. In contrast, molybdenum also makes a significant contribution to corrosion resistance, but is a ferrite former. Therefore, it is favorable if the nickel content is equal to or greater than the molybdenum content. In this context, it is particularly favorable if a nickel content is more than 1.3 times, preferably more than 1.5 times, a molybdenum content.
Stickstoff (N) ist in Gehalten von zumindest 0.35 Gew.-% bis 1.05 Gew.-% erforderlich, um eine hohe Festigkeit sicherzustellen. Weiter trägt Stickstoff zur Korrosionsbeständigkeit bei und ist ein starker Austenitbildner, weswegen höhere Gehalte als 0.40 Gew.-%, insbesondere höher als 0.60 Gew.-%, günstig sind. Auf der anderen Seite steigt mit zunehmendem Stickstoffgehalt die Neigung zu einer Bildung von stickstoffhältigen Ausscheidungen, beispielsweise Cr2N. In vorteilhaften Varianten der Erfindung ist ein Stickstoffgehalt daher mit 0.95 Gew.-%, vorzugsweise 0.90 Gew.-%, begrenzt.Nitrogen (N) is required in amounts of at least 0.35 wt% to 1.05 wt% to ensure high strength. Further, nitrogen contributes to the corrosion resistance and is a strong austenite former, therefore, higher contents than 0.40 wt .-%, especially higher than 0.60 wt .-%, are favorable. On the other hand, as nitrogen content increases, nitrogen-containing precipitate formation tends to increase, for example, Cr 2 N. In advantageous variants of the invention, nitrogen content is therefore limited to 0.95% by weight, preferably 0.90% by weight.
Als vorteilhaft hat sich erwiesen, wenn das Verhältnis der Gewichtsanteile von Stickstoff zu Kohlenstoff größer als 15 ist, weil dann eine Bildung von rein karbidhältigen Ausscheidungen, welche sich äußerst nachteilig auf eine Korrosionsbeständigkeit des Werkstoffes auswirken, zumindest weitgehend ausgeschlossen ist.It has proven to be advantageous if the ratio of the weight proportions of nitrogen to carbon is greater than 15, because then a formation of pure carbide-containing precipitates, which have an extremely adverse effect on corrosion resistance of the material, at least largely excluded.
Bor (B) kann in Gehalten bis zu 0.005 Gew.-% vorgesehen sein und begünstigt insbesondere in einem Bereich von 0.0005 Gew.-% bis 0.004 Gew.-% eine Warmverformbarkeit des erfindungsgemäß zusammensetzten Werkstoffes.Boron (B) can be provided in amounts of up to 0.005% by weight and, in particular in a range from 0.0005% by weight to 0.004% by weight, promotes hot workability of the material composed according to the invention.
Kupfer (Cu) ist in einer erfindungsgemäßen Stahllegierung in einem Gehalt von weniger als 0.5 Gew.-% tolerierbar. In Gehalten von 0.04 Gew.-% bis 0.35 Gew.-% erweist sich Kupfer als durchaus vorteilhaft bei speziellen Einsatzzwecken von Bohrstangen, beispielsweise wenn Bohrstangen bei Bohrungen mit Medien wie Schwefelwasserstoffen, insbesondere H2S, in Kontakt kommen. Gehalte höher als 0.5 Gew.-% fördern eine Ausscheidungsbildung und erweisen sich als nachteilig für die Korrosionsbeständigkeit.Copper (Cu) is tolerable in a steel alloy according to the invention in a content of less than 0.5 wt .-%. At levels of 0.04 wt.% To 0.35 wt.%, Copper proves to be quite advantageous in special drill bit applications, for example when boring bars come in contact with media such as hydrogen sulfide, especially H 2 S. Contents higher than 0.5% by weight promote precipitation formation and are disadvantageous for corrosion resistance.
Aluminium (Al) trägt neben Silicium zu einer Desoxidation des Stahles bei, ist jedoch ein starker Nitridbildner, weshalb dieses Element gewichtsmäßig auf weniger als 0.05 Gew.-% eingeschränkt wird.Aluminum (Al) contributes to deoxidation of the steel besides silicon, but is a strong nitride former, which limits this element to less than 0.05% by weight.
Schwefel (S) ist in Gehalten bis zu 0.30 Gew.-% vorgesehen. Größere Gehalte als 0.1 Gew.-% wirken sich sehr günstig auf eine Verarbeitung einer erfindungsgemäßen Stahllegierung aus, weil eine spanabhebende Bearbeitung erleichtert ist. Wenn jedoch ein Augenmerk höchster Korrosionsbeständigkeit des Werkstoffes gilt, ist ein Schwefelgehalt mit 0.015 Gew.-% begrenzt.Sulfur (S) is provided at levels up to 0.30% by weight. Greater contents than 0.1% by weight have a very favorable effect on the processing of a steel alloy according to the invention, because machining is facilitated. However, if one considers the highest corrosion resistance of the material, a sulfur content of 0.015 wt .-% is limited.
In einer Stahllegierung gemäß der Erfindung ist der Gehalt an Phosphor (P) geringer als 0.035 Gew.-%. Vorzugsweise ist ein Phosphorgehalt mit maximal 0.02 Gew.-% begrenzt.In a steel alloy according to the invention, the content of phosphorus (P) is less than 0.035% by weight. Preferably, a phosphorus content is limited to a maximum of 0.02 wt .-%.
Vanadium (V), Niob (Nb), Titan (Ti) wirken komfeinend im Stahl und können zu diesem Zweck einzeln oder in beliebiger Kombination vorhanden sein, wobei eine Summenkonzentration der vorhandenen Elemente maximal 0.85 Gew.-% beträgt. Im Hinblick auf eine kornfeinende Wirkung und eine Vermeidung von groben Ausscheidungen dieser starken Karbidbildner, ist es von Vorteil, wenn eine Summenkonzentration der vorhandenen Elemente mehr als 0.08 Gew.-% und weniger als 0.45 Gew.-% beträgt.Vanadium (V), niobium (Nb), titanium (Ti) act in a complementary manner in the steel and can be present for this purpose individually or in any desired combination, with a maximum concentration of the elements present being at most 0.85% by weight. In view of a grain-refining effect and avoidance of coarse precipitations of these strong carbide formers, it is beneficial if a sum concentration of the elements present is more than 0.08% by weight and less than 0.45% by weight.
In einer erfindungsgemäßen Stahllegierung tragen die Elemente Wolfram, Molybdän, Mangan, Chrom, Vanadium, Niob und Titan positiv zur Löslichkeit von Stickstoff bei.In a steel alloy according to the invention, the elements tungsten, molybdenum, manganese, chromium, vanadium, niobium and titanium contribute positively to the solubility of nitrogen.
Es ist besonders günstig, wenn Halbzeug aus einer erfindungsgemäßen Legierung bei einer Temperatur von mehr als 750 °C warmverformt, wahlweise lösungsgeglüht und abgeschreckt, und anschließend bei einer Temperatur unterhalb der Rekristallisationstemperatur, vorzugsweise unterhalb von 600°C, insbesondere im Temperaturbereich von 300 °C bis 500 °C, verformt ist. In diesem Zustand des Werkstoffes liegt ein Gefüge frei von stickstoffhältigen und/oder karbidischen Ausscheidungen vor. Bei Anwendung der genannten Verfahrensschritte kann ein homogenes, feines austenitisches Gefüge ohne Umformmartensit erreicht werden. Derart behandelte Werkstoffe weisen bei Raumtemperatur eine Dauerwechselfestigkeit von mehr als 400 MPa bei 107 Lastwechseln auf.It is particularly favorable when semifinished products of an alloy according to the invention are thermoformed at a temperature of more than 750.degree. C., optionally solution-annealed and quenched, and subsequently at a temperature below the recrystallization temperature, preferably below 600.degree. C., in particular in the temperature range of 300.degree up to 500 ° C, is deformed. In this state of the material, there is a structure free of nitrogen-containing and / or carbidic precipitates. When using the mentioned process steps, a homogeneous, fine austenitic microstructure without Umformmartensit can be achieved. At room temperature, materials treated in this way have a permanent fatigue strength of more than 400 MPa with 10 7 load changes.
Das weitere Ziel der Erfindung, Verwendungen für eine austenitische, im Wesentlichen ferritfreie Legierung anzugeben, wird durch Verwendung einer erfindungsgemäßen Stahllegierung als Werkstoff für Komponenten für die Ölfeldtechnik erreicht. Insbesondere als günstig erweist es sich, wenn die Komponente ein Bohrstrangteil ist.The further object of the invention to provide uses for an austenitic, substantially ferrite-free alloy is achieved by using a steel alloy according to the invention as a material for components for oil field technology. In particular, it proves to be advantageous if the component is a Bohrstrangteil.
Das weitere Ziel der Erfindung wird auch durch Verwendung einer Legierung gemäß der Erfindung für auf Zug und Druck beanspruchte Bauteile, welche mit korrosiven Medien, insbesondere einer korrosiven Flüssigkeit wie salzhältiges Wasser, in Kontakt kommen, erreicht.The further object of the invention is also achieved by using an alloy according to the invention for tensile and compression stressed components, which come into contact with corrosive media, in particular a corrosive liquid such as saline water.
Die Vorteile einer erfindungsgemäßen Verwendung sind insbesondere darin zu sehen, dass bei Einsatz der genannten Legierungen korrosionschemischer Verschleiß verzögert ist und die Komponenten bzw. Bauteile eine erhöhte Gebrauchsdauer aufweisen.The advantages of a use according to the invention can be seen in particular in the fact that when using the alloys mentioned corrosion-chemical Wear is delayed and the components or components have an increased service life.
Im Rahmen einer Weiterverarbeitung von stangenförmigem Material aus einer erfindungsgemäßen Legierung zu Bohrstangen durch Drehen und Schälen hat sich überraschenderweise gezeigt, dass ein Verschleiß von Dreh- bzw. Schälwerkzeugen bei Vergleich mit Material gemäß dem Stand der Technik erheblich verringert ist.As part of a further processing of rod-shaped material from an alloy according to the invention to drill rods by turning and peeling, it has surprisingly been found that wear of rotary or peeling tools is significantly reduced in comparison with the material according to the prior art.
Zufolge diesem Aspekt stellt es ein verfahrensmäßiges Ziel der Erfindung dar, ein Verfahren zur Herstellung von austenitischen, im Wesentlichen ferritfreien Komponenten für die Ölfeldtechnik anzugeben, mit welchem insbesondere Bohrstangen hoher Korrosionsbeständigkeit mit geringerem Werkzeugverschleiß kostengünstig herstellbar sind.In this aspect, it is a procedural object of the invention to provide a process for the production of austenitic, substantially ferrite-free components for the oilfield technique, with which in particular boring bars of high corrosion resistance with less tool wear can be produced cost-effectively.
Das verfahrensgemäße Ziel der Erfindung wird durch ein Verfahren nach Anspruch 26 erreicht.The method of the invention is achieved by a method according to claim 26.
Die mit einem derartigen Verfahren erreichten Vorteile sind insbesondere darin zu sehen, dass Komponenten für die Ölfeldtechnik, welche bei für Einsatzzwecke ausreichenden mechanischen Eigenschaften verbesserte Korrosionsbeständigkeit aufweisen, bei einem um bis zu 12 % verringertem Werkzeugverschleiß herstellbar sind. Ein Homogenisieren kann dabei sowohl vor einem ersten Warmverformungsschritt als auch nach einem ersten Warmverformungsschritt, jedoch vor einem zweiten Warmverformungsschritt, vorgenommen werden.The advantages achieved with such a method can be seen, in particular, in the fact that components for oil field technology, which have improved corrosion resistance for mechanical properties sufficient for purposes of use, can be produced with tool wear reduced by up to 12%. Homogenization can be carried out both before a first hot-forming step and after a first hot-forming step, but before a second hot-forming step.
Höhere Temperaturen erleichtern eine Verformung im Verformungsschritt nach einer verstärkten Abkühlung und es ist daher günstig, wenn dieser bei einer Temperatur des Halbzeuges von über 350°C durchgeführt wird.Higher temperatures facilitate deformation in the deformation step after increased cooling and it is therefore favorable if this is carried out at a temperature of the semi-finished product of about 350 ° C.
Wenn die zu erstellende Komponente eine Bohrstange ist, ist das Halbzeug zweckmäßigerweise eine Stange, welche im zweiten Verformungsschritt mit einem Verformungsgrad von 10 % bis 20 % verformt wird. Derartige Verformungsgrade erbringen eine ausreichende Festigkeit für Einsatzzwecke und erlauben eine Dreh- bzw. Schälbearbeitung bei verringertem Werkzeugverschleiß.If the component to be created is a boring bar, the semifinished product is expediently a bar which is deformed in the second deformation step with a degree of deformation of 10% to 20%. Such degrees of deformation provide sufficient strength for use and permit turning or peeling machining with reduced tool wear.
In Bezug auf eine Güte von erstellten Komponenten hat es sich als günstig erwiesen, wenn ein Block mittels Elektroschlacke-Umschmelz-Verfahren hergestellt wird.In terms of quality of manufactured components, it has been found to be beneficial to produce a block by electroslag remelting.
Eine rasche und kostengünstige Fertigung von Komponenten wird ermöglicht, wenn die spanabhebende Bearbeitung ein Drehen und/oder Schälen umfasst.Rapid and cost effective component manufacturing is enabled when the machining involves turning and / or peeling.
Im Folgenden ist die Erfindung anhand von Beispielen noch weiter erläutert.In the following, the invention is explained in more detail by way of examples.
Durch Schmelzen unter Atmosphärendruck wurden Blöcke erstellt, deren chemische Zusammensetzungen den Legierungen 1 bis 5 sowie 7 in Tabelle 1 entsprechen. Ein Gusstück aus Legierung 6 in Tabelle 1 wurde unter Stickstoffatmosphäre bei 16 bar Druck umgeschmolzen und aufgestickt. Die porenfreien Blöcke wurden anschließend bei 1200 °C homogenisiert und bei 910 °C mit einem Verformungsgrad von 75 % warmverformt [Verformungsgrad = ((Ausgangsquerschnitt - Endquerschnitt) / Ausgangsquerschnitt)* 100]. Danach folgte eine Lösungsglühbehandlung zwischen 1000 °C und 1100 °C. Anschließend wurden die zu Halbzeug verformten Blöcke mit Wasser auf Umgebungstemperatur abgeschreckt und schließlich bei Temperatur von 380 °C bis 420°C einem zweiten Verformungsschritt unterworfen, wobei ein Verformungsgrad 13 % bis 17 % betrug. Die so erstellten Gegenstände wurden untersucht bzw. zu Bohrstangen weiterverarbeitet.By melting under atmospheric pressure, blocks were prepared whose chemical compositions correspond to alloys 1 to 5 and 7 in Table 1. An alloy 6 cast in Table 1 was remelted under nitrogen atmosphere at 16 bar pressure and stitched. The pore-free blocks were then homogenized at 1200 ° C and thermoformed at 910 ° C with a degree of deformation of 75% [degree of deformation = ((initial cross section - final cross-section) / output cross-section) * 100]. Thereafter, a solution annealing treatment between 1000 ° C and 1100 ° C followed. Subsequently, the semifinished blocks were quenched with water to ambient temperature and finally subjected to a second deformation step at a temperature of 380 ° C to 420 ° C, with a degree of deformation of 13% to 17%. The objects created in this way were examined or further processed into boring bars.
Legierungen A, B, C, D und E, deren Zusammensetzungen ebenfalls aus Tabelle 1 ersichtlich sind, stellen am Markt erhältliche Produkte dar.Alloys A, B, C, D and E, the compositions of which are also shown in Table 1, represent products available on the market.
Gegenstände aus diesen Legierungen wurden zu Vergleichszwecken ebenfalls untersucht bzw. bearbeitet.
Die in Tabelle 1 angeführten Legierungen wurden hinsichtlich Lochfraßkorrosionsbeständigkeit und Spannungsrisskorrosion untersucht. Die Bestimmung der Lochfraßkorrosionsbeständigkeit erfolgte durch Messung des Lochkorrosionspotentials gegenüber einer Standard-Wasserstoffelektrode nach ASTM G 61. Die Spannungsrisskorrosion (SCC) wurde durch Ermittlung des Wertes der SCC-Grenzspannung nach ATSM G 36 bestimmt. Der Wert der SCC-Grenzspannung steht für jene außen angelegte maximale Prüfspannung, welche eine Prüfprobe mehr als 720 Stunden in bei 155 °C siedender 45%-MgCl2-Lösung erträgt.The alloys listed in Table 1 were examined for pitting corrosion resistance and stress corrosion cracking. The determination of the pitting corrosion resistance was carried out by measuring the pitting potential against a standard hydrogen electrode according to ASTM G 61. The stress corrosion cracking (SCC) was determined by determining the value of the SCC limit stress according to ATSM G 36. The value of the SCC cut-off voltage represents the externally applied maximum test voltage which a test sample can withstand for more than 720 hours in 155% boiling 45% MgCl 2 solution.
Untersuchungen an Gegenständen aus den in Tabelle 1 angeführten Legierungen belegen bei hohen mechanischen Kennwerten eine überragende Korrosionsbeständigkeit von erfindungsgemäßen Werkstoffen. Vor allem im Vergleich mit den aus dem Stand der Technik bekannten Cr-Mn-Austeniten (Legierungen A, B und C) zeigt sich gemäß Tabelle 2 und Tabelle 3, dass erfindungsgemäße Legierungen bei guten mechanischen Eigenschaften deutlich korrosionsbeständiger sind. Dabei zeigt sich eine erhöhte Beständigkeit erfindungsgemäßer Legierungen sowohl gegen Lochfraßkorrosion als auch gegen Spannungsrisskorrosion.Investigations on objects from the alloys listed in Table 1 prove at high mechanical properties superior corrosion resistance of materials of the invention. Especially in comparison with the known from the prior art Cr-Mn austenites (alloys A, B and C) is shown in Table 2 and Table 3, that Alloys of the invention are significantly more corrosion resistant with good mechanical properties. This shows an increased resistance of alloys according to the invention both against pitting corrosion and against stress corrosion cracking.
Ein Lochkorrosionspotential Epit bzw. eine SCC-Grenzspannung kann sogar Werte entsprechend jenen von hochlegierten Cr-Ni-Mo-Stählen und Nickelbasislegierungen erreichen, wobei gleichzeitig, wie die Tabellen 4 und 5 belegen, bessere Festigkeitseigenschaften gegeben sind. Besonders günstig ist dabei mit Bezug auf eine SCC-Grenzspannung, wenn ein Summengehalt von Molybdän und Nickel 4.7 Gew.-% oder mehr, insbesondere mehr als 6 Gew.-%, beträgt.
(25 °C, 80000 ppm Cl -)
(60°C, synthetisches Meerwasser)
(PREN = Gew.-%Cr + 3,3* Gew.-%Mo + 16* Gew.-%N)
[Gew: %]
[Gew.%]
[Gew.%]
[MPa]
(25 ° C, 80000 ppm Cl - )
(60 ° C, synthetic seawater)
(PREN = wt% Cr + 3.3 * wt% Mo + 16 * wt% N)
[Weight:%]
[Wt.%]
[Wt.%]
[MPa]
Weitere Erprobungen zeigten, dass Gegenstände aus den erfindungsgemäßen Legierungen 1 bis 7 eine relative magnetische Permeabilität von µr < 1.005 und bei Raumtemperatur Dauerwechselfestigkeiten von zumindest 400 MPa bei 107 Lastwechsel aufweisen.Further tests have shown that articles made of the alloys 1 to 7 according to the invention have a relative magnetic permeability of μ r <1,005 and at room temperature permanent fatigue strengths of at least 400 MPa at 10 7 load changes.
Bei einer spanabhebenden Bearbeitung von stangenförmigem Material aus Legierung C sowie Material aus der Legierungen 3 und 4 im Rahmen einer Herstellung von Bohrstangen konnten Wendeschneidplatten bei Bearbeitung der Legierungen 3 und 4 um 12 % länger eingesetzt werden als bei Bearbeitung von Stangen aus Legierung C. Somit können Bohrstangen, welche hohe mechanische Kennwerte und eine verbesserte Korrosionsbeständigkeit aufweisen, mit geringerem Werkzeugverschleiß erzeugt werden.In machining of Alloy C rod-shaped material and Alloy 3 and 4 material in the production of boring bars, indexable inserts could be used 12% longer when machining Alloys 3 and 4 than when machining Alloy C rods Boring bars, which have high mechanical characteristics and improved corrosion resistance, are produced with less tool wear.
Durch die Kombination aus höchster Festigkeit mit guter Zähigkeit und besten Korrosionseigenschaften eignet sich eine erfindungsgemäße Legierung optimal auch als Werkstoff für Befestigungs- oder Verbindungselemente, wie Schrauben, Nägel, Bolzen oder dergleichen Komponenten, wenn diese hohen mechanischen Belastungen sowie aggressiven Umgebungsbedingungen ausgesetzt sind.Due to the combination of highest strength with good toughness and best corrosion properties, an alloy according to the invention is also optimally suitable as a material for fastening or connecting elements, such as Screws, nails, bolts or similar components, if they are exposed to high mechanical loads and aggressive environmental conditions.
Ein weiteres Anwendungsfeld, in dem Legierungen gemäß der Erfindung mit Vorteil Verwendung finden, liegt im Bereich korrosions- und verschleißbeanspruchter Teile wie Prallbleche oder Teilen, die hohen Belastungsgeschwindigkeiten ausgesetzt sind. In diesen Einsatzgebieten können Komponenten aus erfindungsgemäßen Legierungen auf Grund ihrer Eigenschaftskombination geringsten Materialverschleiß und damit eine maximale Lebensdauer erzielen.Another field of application in which alloys according to the invention find advantageous use is in the field of corrosion and wear parts such as baffles or parts that are exposed to high loading speeds. In these applications, components of alloys of the invention due to their combination of properties lowest material wear and thus achieve maximum life.
Claims (30)
- Austenitic, substantially ferrite-free steel alloy comprising (in % by weight)
up to 0.15% of carbon
up to 0.75% of silicon
more than 19.0% to 30.0% of manganese
more than 17.0% to 24.0% of chromium
more than 1.90% to 5.5% of molybdenum
up to 2.0% of tungsten
2.50% to 15.0% of nickel
up to 5.0% of cobalt
0.60% to 1.05% of nitrogen
up to 0.005% of boron
up to 0.30% of sulphur
less than 0.5% of copper
less than about 0.05% of aluminium
less than 0.035% of phosphorus,
and optionally one or more element(s) selected from the group consisting of vanadium, niobium and titanium, the total concentration of the selected elements being not more than 0.85% by weight,
remainder iron and production-related impurities. - Steel alloy according to Claim 1, comprising (in % by weight) at least 2.65%, preferably at least 3.6%, in particular 3.8% to 9.8%, of nickel.
- Steel alloy according to Claim 1 or 2, comprising (in % by weight) less than 0.2% of cobalt.
- Steel alloy according to one of Claims 1 to 3, comprising (in % by weight) 2.05% to 5.0%, preferably 2.5% to 4.5%, of molybdenum.
- Steel alloy according to one of Claims 1 to 4, comprising (in % by weight) more than 20.0% to 25.5% of manganese.
- Steel alloy according to one of Claims 1 to 5, comprising (in % by weight) 19.0% to 23.5%, preferably 20.0% to 23.0%, of chromium.
- Steel alloy according to one of Claims 1 to 6, comprising (in % by weight) 0.15% to 0.30% of silicon.
- Steel alloy according to one of Claims 1 to 7, comprising (in % by weight) 0.01% to 0.06% of carbon.
- Steel alloy according to one of Claims 1 to 8, comprising (in % by weight) up to 0.95%, preferably up to 0.90%, of nitrogen.
- Steel alloy according to one of Claims 1 to 9, where the ratio of the proportions by weight of nitrogen to carbon is greater than 15.
- Steel alloy according to one of Claims 1 to 10, comprising (in % by weight) 0.04% to 0.35% of copper.
- Steel alloy according to one of Claims 1 to 11, comprising (in % by weight) 0.0005% to 0.004% of boron.
- Steel alloy according to one of Claims 1 to 12, with the proviso that the nickel content is equal to or greater than the molybdenum content.
- Steel alloy according to one of Claims 1 to 13, where the nickel content is more than 1.3 times, preferably more than 1.5 times, the molybdenum content.
- Steel alloy according to one of Claims 1 to 14, comprising at least two elements selected from the group consisting of
vanadium
niobium
titanium,
where the total proportion by weight of these elements is more than 0.08% by weight and less than 0.45% by weight. - Steel alloy according to one of Claims 1 to 15, comprising (in % by weight) not more than 0.015% of sulphur.
- Steel alloy according to one of Claims 1 to 16, comprising (in % by weight) not more than 0.02% of phosphorus.
- Steel alloy according to one of Claims 1 to 17, comprising molybdenum and tungsten, where the total content X (in % by weight) calculated according to
X = (% molybdenum) + 0.5*(% tungsten) is greater than 2 and less than 5.5. - Steel alloy according to one of Claims 1 to 18, having a fatigue limit under reversed stresses at room temperature of greater than 400 MPa at 107 loadings.
- Steel alloy according to one of Claims 1 to 19, which is substantially free of nitrogen-containing and/or carbide precipitates.
- Steel alloy according to one of Claims 1 to 20, which is hot-formed at a temperature of more than 750°C, thereafter optionally solution-annealed and subsequently formed at a temperature below the recrystallisation temperature, preferably below 600°C, in particular in the temperature range from 300°C to 5,50°C.
- Steel alloy according to one of Claims 1 to 21, which is in the form of a component for oilfield technology, in particular in the form of a drilling string part.
- Use of a steel alloy according to one of Claims 1 to 21 as a material for components for oilfield technology.
- Use of a steel alloy according to Claim 23, where the component is a drill string part.
- Use of a steel alloy according to one of Claims 1 to 21 for components subjected to tensile and compressive stress which come into contact with corrosive media, in particular a corrosive liquid, such as saline water.
- Process for producing austenitic, substantially ferrite-free components, in particular drill rods, for oilfield technology, where first of all
a casting comprising (in % by weight)
up to 0.15% of carbon
up to 0.75% of silicon
more than 19.0% to 30.0% of manganese
more than 17.0% to 24.0% of chromium
more than 1.90% to 5.5% of molybdenum
up to 2.0% of tungsten
2.50% to 15.0% of nickel
up to 5.0% of cobalt
0.60% to 1.05% of nitrogen
up to 0.005% of boron
up to 0.30% of sulphur
less than 0.5% of copper
less than 0.05% of aluminium
less than 0.035% of phosphorus,
and optionally one or more element(s) selected from the group consisting of vanadium, niobium and titanium, the total concentration of the selected elements being not more than 0.85% by weight,
remainder iron and production-related impurities,
is produced,
whereupon the casting is formed at a temperature of more than 750°C into a semi-finished product in two or more hot-forming partial steps, in which optionally before the first partial step or between the partial steps a homogenisation of the semi-finished product is carried out at a temperature of more than 1150°C, whereupon after the last hot-forming partial step and a solution-annealing, optionally carried out thereafter, of the semi-finished product at a temperature of more than 900°C the semi-finished product is subjected to intensified cooling and in a further forming step formed at a temperature below the recrystallisation temperature, in particular below 600°C, after which a component is produced from the semi-finished product by machining. - Process according to Claim 26, where the forming step is carried out after intensified cooling at a temperature of the semi-finished product of over 350°C.
- Process according to Claim 26 or 27, where the semi-finished product is a rod and the latter is formed in the second forming step with a degree of deformation of 10% to 20%.
- Process according to one of Claims 26 to 28, where the casting produced is remelted by means of electroslag remelting.
- Process according to one of Claims 26 to 29, where the machining comprises turning and/or peeling.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT0193803A AT412727B (en) | 2003-12-03 | 2003-12-03 | CORROSION RESISTANT, AUSTENITIC STEEL ALLOY |
| AT19382003 | 2003-12-03 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP1538232A1 EP1538232A1 (en) | 2005-06-08 |
| EP1538232B1 true EP1538232B1 (en) | 2007-01-03 |
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| Application Number | Title | Priority Date | Filing Date |
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| EP04450211A Active EP1538232B1 (en) | 2003-12-03 | 2004-11-17 | Corrosion resistant austenitic steel |
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| US (3) | US7708841B2 (en) |
| EP (1) | EP1538232B1 (en) |
| AT (2) | AT412727B (en) |
| CA (1) | CA2488965C (en) |
| DE (1) | DE502004002524D1 (en) |
| ES (1) | ES2280936T3 (en) |
| NO (1) | NO340359B1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| US20040221929A1 (en) | 2003-05-09 | 2004-11-11 | Hebda John J. | Processing of titanium-aluminum-vanadium alloys and products made thereby |
| AT412727B (en) | 2003-12-03 | 2005-06-27 | Boehler Edelstahl | CORROSION RESISTANT, AUSTENITIC STEEL ALLOY |
| US7837812B2 (en) | 2004-05-21 | 2010-11-23 | Ati Properties, Inc. | Metastable beta-titanium alloys and methods of processing the same by direct aging |
| US10316616B2 (en) | 2004-05-28 | 2019-06-11 | Schlumberger Technology Corporation | Dissolvable bridge plug |
| US8770261B2 (en) | 2006-02-09 | 2014-07-08 | Schlumberger Technology Corporation | Methods of manufacturing degradable alloys and products made from degradable alloys |
| EP2035593B1 (en) * | 2006-06-23 | 2010-08-11 | Jorgensen Forge Corporation | Austenitic paramagnetic corrosion resistant material |
| US7658883B2 (en) * | 2006-12-18 | 2010-02-09 | Schlumberger Technology Corporation | Interstitially strengthened high carbon and high nitrogen austenitic alloys, oilfield apparatus comprising same, and methods of making and using same |
| US8535606B2 (en) * | 2008-07-11 | 2013-09-17 | Baker Hughes Incorporated | Pitting corrosion resistant non-magnetic stainless steel |
| JP5526809B2 (en) | 2009-04-27 | 2014-06-18 | 大同特殊鋼株式会社 | High corrosion resistance, high strength, non-magnetic stainless steel and high corrosion resistance, high strength, non magnetic stainless steel products and methods for producing the same |
| US10053758B2 (en) | 2010-01-22 | 2018-08-21 | Ati Properties Llc | Production of high strength titanium |
| US9255316B2 (en) | 2010-07-19 | 2016-02-09 | Ati Properties, Inc. | Processing of α+β titanium alloys |
| US8613818B2 (en) | 2010-09-15 | 2013-12-24 | Ati Properties, Inc. | Processing routes for titanium and titanium alloys |
| US9206497B2 (en) | 2010-09-15 | 2015-12-08 | Ati Properties, Inc. | Methods for processing titanium alloys |
| US10513755B2 (en) | 2010-09-23 | 2019-12-24 | Ati Properties Llc | High strength alpha/beta titanium alloy fasteners and fastener stock |
| US8652400B2 (en) | 2011-06-01 | 2014-02-18 | Ati Properties, Inc. | Thermo-mechanical processing of nickel-base alloys |
| US9347121B2 (en) * | 2011-12-20 | 2016-05-24 | Ati Properties, Inc. | High strength, corrosion resistant austenitic alloys |
| US9869003B2 (en) | 2013-02-26 | 2018-01-16 | Ati Properties Llc | Methods for processing alloys |
| DE102013003516A1 (en) * | 2013-03-04 | 2014-09-04 | Outokumpu Nirosta Gmbh | Process for the production of an ultra-high-strength material with high elongation |
| US9192981B2 (en) | 2013-03-11 | 2015-11-24 | Ati Properties, Inc. | Thermomechanical processing of high strength non-magnetic corrosion resistant material |
| US9777361B2 (en) | 2013-03-15 | 2017-10-03 | Ati Properties Llc | Thermomechanical processing of alpha-beta titanium alloys |
| US11111552B2 (en) | 2013-11-12 | 2021-09-07 | Ati Properties Llc | Methods for processing metal alloys |
| US10094003B2 (en) | 2015-01-12 | 2018-10-09 | Ati Properties Llc | Titanium alloy |
| US10502252B2 (en) | 2015-11-23 | 2019-12-10 | Ati Properties Llc | Processing of alpha-beta titanium alloys |
| BR102016001063B1 (en) * | 2016-01-18 | 2021-06-08 | Amsted Maxion Fundição E Equipamentos Ferroviários S/A | alloy steel for railway components, and process for obtaining a steel alloy for railway components |
| GB2546808B (en) * | 2016-02-01 | 2018-09-12 | Rolls Royce Plc | Low cobalt hard facing alloy |
| GB2546809B (en) * | 2016-02-01 | 2018-05-09 | Rolls Royce Plc | Low cobalt hard facing alloy |
| MY192988A (en) | 2018-08-03 | 2022-09-20 | Jfe Steel Corp | High-mn steel and method for producing same |
| CA3033698A1 (en) | 2018-10-10 | 2020-04-10 | Repeat Precision, Llc | Setting tools and assemblies for setting a downhole isolation device such as a frac plug |
| DE102018133251A1 (en) | 2018-12-20 | 2020-06-25 | Schoeller-Bleckmann Oilfield Technology Gmbh | Drill string component with high corrosion resistance and process for their manufacture |
| CN112251686B (en) * | 2020-09-29 | 2022-03-18 | 中国科学院金属研究所 | Ultrahigh-strength nanocrystalline 4Cr5MoWSi die steel and preparation method thereof |
Family Cites Families (23)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB432434A (en) | 1934-01-26 | 1935-07-26 | British Thomson Houston Co Ltd | Improvements in and relating to electric discharge devices |
| US3936297A (en) * | 1972-05-08 | 1976-02-03 | Allegheny Ludlum Industries, Inc. | Method of producing austenitic stainless steel |
| US3820980A (en) | 1972-05-08 | 1974-06-28 | Allegheny Ludlum Ind Inc | Austenitic stainless steel |
| US3847599A (en) * | 1973-10-04 | 1974-11-12 | Allegheny Ludlum Ind Inc | Corrosion resistant austenitic steel |
| US3880654A (en) | 1973-11-28 | 1975-04-29 | Allegheny Ludlum Ind Inc | Corrosion resistant austenitic steel |
| US3938990A (en) | 1973-11-28 | 1976-02-17 | Allegheny Ludlum Industries, Inc. | Method of making corrosion resistant austenitic steel |
| US4217136A (en) | 1974-05-01 | 1980-08-12 | Allegheny Ludlum Steel Corporation | Corrosion resistant austenitic stainless steel |
| WO1980001233A1 (en) | 1978-12-22 | 1980-06-26 | Gygli Technik Ag | Collar for garment |
| DE3143096A1 (en) * | 1980-11-05 | 1982-05-19 | General Electric Co., Schenectady, N.Y. | Iron-based alloy, process for producing it, and articles manufactured with it |
| CA1205659A (en) | 1981-03-20 | 1986-06-10 | Masao Yamamoto | Corrosion-resistant non-magnetic steel and retaining ring for a generator made of it |
| DE8132785U1 (en) | 1981-11-10 | 1982-04-15 | Vorwerk & Co Interholding Gmbh, 5600 Wuppertal | HANDLE FOR THE GUIDE OF A HAND VACUUM CLEANER |
| JPS59205451A (en) * | 1983-05-09 | 1984-11-21 | Nippon Yakin Kogyo Co Ltd | High strength non-magnetic steel |
| AT381658B (en) * | 1985-06-25 | 1986-11-10 | Ver Edelstahlwerke Ag | METHOD FOR PRODUCING AMAGNETIC DRILL STRING PARTS |
| JPS62109951A (en) * | 1985-11-07 | 1987-05-21 | Sumitomo Metal Ind Ltd | Steel for nonmagnetic drill collar |
| DE3940438C1 (en) * | 1989-12-07 | 1991-05-23 | Vereinigte Schmiedewerke Gmbh, 4630 Bochum, De | |
| US5094812A (en) * | 1990-04-12 | 1992-03-10 | Carpenter Technology Corporation | Austenitic, non-magnetic, stainless steel alloy |
| JPH06116683A (en) * | 1992-10-01 | 1994-04-26 | Kobe Steel Ltd | High mn nonmagnetic steel excellent in machinability and corrosion resistance |
| JPH0762432A (en) * | 1993-08-27 | 1995-03-07 | Kobe Steel Ltd | Manufacture of high strength non-magnetic ring chain excellent in corrosion resistance and heat resistance |
| DE19607828C2 (en) * | 1995-04-15 | 2003-06-18 | Vsg En Und Schmiedetechnik Gmb | Process for producing an austenitic Cv-Mn steel |
| DE19758613C2 (en) * | 1997-04-22 | 2000-12-07 | Krupp Vdm Gmbh | High-strength and corrosion-resistant iron-manganese-chrome alloy |
| AT407882B (en) * | 1999-07-15 | 2001-07-25 | Schoeller Bleckmann Oilfield T | METHOD FOR PRODUCING A PARAMAGNETIC, CORROSION-RESISTANT MATERIAL AND THE LIKE MATERIALS WITH A HIGH STRETCH LIMIT, STRENGTH AND TENSITY |
| AT412727B (en) | 2003-12-03 | 2005-06-27 | Boehler Edelstahl | CORROSION RESISTANT, AUSTENITIC STEEL ALLOY |
| EP2035593B1 (en) | 2006-06-23 | 2010-08-11 | Jorgensen Forge Corporation | Austenitic paramagnetic corrosion resistant material |
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- 2004-11-17 ES ES04450211T patent/ES2280936T3/en active Active
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Also Published As
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| AT412727B (en) | 2005-06-27 |
| CA2488965C (en) | 2013-04-09 |
| US7708841B2 (en) | 2010-05-04 |
| ATA19382003A (en) | 2004-11-15 |
| EP1538232A1 (en) | 2005-06-08 |
| CA2488965A1 (en) | 2005-06-03 |
| US8454765B2 (en) | 2013-06-04 |
| NO340359B1 (en) | 2017-04-10 |
| ES2280936T3 (en) | 2007-09-16 |
| US20100170596A1 (en) | 2010-07-08 |
| US20050145308A1 (en) | 2005-07-07 |
| DE502004002524D1 (en) | 2007-02-15 |
| US7947136B2 (en) | 2011-05-24 |
| ATE350505T1 (en) | 2007-01-15 |
| US20110253262A1 (en) | 2011-10-20 |
| NO20045271L (en) | 2005-06-06 |
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