EP0432434B1 - Process for manufacturing joining structural parts from a fully austenitic Cr-Mn steel. - Google Patents
Process for manufacturing joining structural parts from a fully austenitic Cr-Mn steel. Download PDFInfo
- Publication number
- EP0432434B1 EP0432434B1 EP90120990A EP90120990A EP0432434B1 EP 0432434 B1 EP0432434 B1 EP 0432434B1 EP 90120990 A EP90120990 A EP 90120990A EP 90120990 A EP90120990 A EP 90120990A EP 0432434 B1 EP0432434 B1 EP 0432434B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- max
- steel
- diameter
- preliminary
- product
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- 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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
Definitions
- the invention relates to a method for producing connecting elements, in particular bolts, screws, nails or wire ropes with a yield strength of at least 1800 N / mm2.
- AT-PS 337 235 relates to an austenitic stainless steel consisting of 10 to 30% chromium 15 to 45% manganese 0.85 to 3% nitrogen 0.015 to 1% carbon 0.19 to 2% silicon Balance iron and manufacturing-related impurities.
- This steel is particularly suitable for highly stressed brackets, in motor-generator construction, for submarine cables and for the manufacture of pump housings. In the fully austenitic state, the steel can reach yield strength values of up to 1600 N / mm2 if it is cold-reduced by up to 50%.
- the steel has a chromium content of 15 to 27% and a manganese content of 21 to 30% according to a formula specified in the AT-PS. Since the steel is melted at atmospheric pressure, the high levels of chromium and manganese are necessary in order to increase the solubility limit of nitrogen in the steel when nitrogen carriers are added.
- the austenitic nitrogen-containing steel melted according to the AT-PS is characterized by a low porosity.
- the material breaks at higher degrees of cold reduction, for example when drawing starting material into thin wire cross sections. Porosity in the micro range was also observed. Apart from these metallurgical difficulties, such a steel is very expensive for large-scale use due to its high chromium and manganese content.
- the production can include the production of blocks after the electro-slag remelting under increased pressure with the addition of nitrogen carriers or the introduction of nitrogen gas, as well as forging and solution annealing. This is followed by quenching in water and uniaxial cold processing. Stress relief annealing at 350 ° C for 2 hours completes the production process of the starting material for the production of the rings.
- the object of the invention is to produce high-strength, corrosion-resistant connecting elements.
- the steels of the type according to the invention should be able to be cold worked almost indefinitely. For this purpose, they should be able to be machined from relatively high initial cross sections to the thinnest dimensions without the risk of breakage.
- the required yield strength values of greater than 1800 N / mm2 can be achieved with certainty, in particular by the outsourcing of the end product preformed with the highest cross-sectional decreases at temperatures of 300 to 500 ° C for a time of 20 times adapted to the cross section Minutes to 5 hours.
- This aging treatment results in a rearrangement of the dislocations within the steel formed during the previous cold-forming processes, and without changing the so-called dislocation density, which is ultimately responsible for the high strength of these steels.
- An independent variant for solving the problem according to the invention consists in the use of powder instead of a cast product as the starting material according to claim 2.
- the metal powder is shaped by hot isostatic pressing into a billet, which is then forged and / or rolled out to a billet of 5 to 150 mm in diameter is, the preliminary product is then cold-formed with a cross-sectional decrease of at least 60% to an end product with a diameter of 0.5 to 90 mm and then the end product is aged at temperatures of 300 to 500 ° C for a period of 20 minutes to 5 hours.
- Bolts, screws, nails and wire ropes are preferably produced by the method according to the invention.
- an electrode of the following composition in mass%) carbon 0.06% silicon 0.41% manganese 19.43% phosphorus 0.012% sulfur 0.008% chrome 18.25% molybdenum 0.81% nickel 0.37% Remainder iron, melted and at the same time adjusted to a nitrogen content of 0.88% by adding nitrogenous materials.
- the steel block solidified in the pressure electro-slag remelting furnace with the above overall analysis was then brought to a cross-section of 7 mm in diameter by forging and rolling.
- the diameter was cold drawn from 7 mm to 3 mm in 8 passes. This corresponds to a total deformation of 82% (approx. 10% cold deformation per train).
- the wire was further cold drawn from a diameter of 3 mm to 1.8 mm.
- the total deformation was 64% in 6 moves (approx. 10% deformation per move).
- the wire drawn to 1.8 mm in diameter was then aged at a temperature of 400 ° C. for 4 hours.
- the corresponding values before the aging treatment were 2100 N / mm2 for the yield strength, 2220 N / mm2 for the tensile strength, 6% for the elongation and 46% for the fracture constriction.
- the aging treatment according to the invention is of high importance. With this aging treatment it is possible to set yield strengths and tensile strength values that were previously unknown. It is particularly surprising that the values for the toughness, expressed here by the elongation and the fracture constriction, remain constant.
- the steels remain non-magnetic even at the highest degrees of deformation. It also reduces susceptibility to stress corrosion cracking in dilute aqueous solutions up to 80 ° C.
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Herstellung von Verbindungselementen, insbesondere Bolzen, Schrauben, Nägel oder von Drahtseilen mit einer Streckgrenze von mindestens 1800 N/mm².The invention relates to a method for producing connecting elements, in particular bolts, screws, nails or wire ropes with a yield strength of at least 1800 N / mm².
Die AT-PS 337 235 betrifft einen austenitischen rostfreien Stahl, bestehend aus
10 bis 30 % Chrom
15 bis 45 % Mangan
0,85 bis 3 % Stickstoff
0,015 bis 1 % Kohlenstoff
0,19 bis 2 % Silizium
Rest Eisen und herstellungsbedingte Verunreinigungen.AT-PS 337 235 relates to an austenitic stainless steel consisting of
10 to 30% chromium
15 to 45% manganese
0.85 to 3% nitrogen
0.015 to 1% carbon
0.19 to 2% silicon
Balance iron and manufacturing-related impurities.
Dieser Stahl eignet sich besonders vorteilhaft für hochbeanspruchte Halterungen, im Motor-Generatorbau, für Unterseekabel und zur Herstellung von Pumpengehäusen. Der Stahl kann im vollaustenitischen Zustand Streckgrenzenwerte bis 1600 N/mm² erreichen, wenn er bis 50 % kaltreduziert wird.This steel is particularly suitable for highly stressed brackets, in motor-generator construction, for submarine cables and for the manufacture of pump housings. In the fully austenitic state, the steel can reach yield strength values of up to 1600 N / mm² if it is cold-reduced by up to 50%.
Voraussetzung für das Erreichen solch hoher Streckgrenzenwerte ist jedoch, daß der Stahl nach einer in der AT-PS festgelegten Formel Chromgehalte von 15 bis 27 % sowie Mangangehalte von 21 bis 30 % aufweist. Da der Stahl bei Atmosphärendruck erschmolzen wird, sind die hohen Gehalte an Chrom und Mangan erforderlich, um die Löslichkeitsgrenze des Stickstoffs im Stahl bei Zugabe von Stickstoffträgern entsprechend zu erhöhen. Der nach der AT-PS erschmolzene austenitische stickstoffhaltige Stahl zeichnet sich zwar durch eine geringe Porosität aus. Es hat sich jedoch gezeigt, daß ein solcher Stahl nicht durch Kaltreduzieren mit Verformungsgraden oberhalb 50 % auf über 1600 N/mm² liegende Streckgrenzenwerte gebracht werden kann. Versuche haben ergeben, daß bei höheren Kaltreduktionsgraden, beispielsweise beim Ziehen von Vormaterial zu dünnen Drahtquerschnitten, das Material bricht. Außerdem wurde Porosität im Mikrobereich beobachtet. Abgesehen von diesen metallurgischen Schwierigkeiten ist ein solcher Stahl für den großtechnischen Einsatz infolge seiner hohen Chrom- und Mangangehalte sehr teuer.Prerequisite for reaching such high Yield strength values, however, are that the steel has a chromium content of 15 to 27% and a manganese content of 21 to 30% according to a formula specified in the AT-PS. Since the steel is melted at atmospheric pressure, the high levels of chromium and manganese are necessary in order to increase the solubility limit of nitrogen in the steel when nitrogen carriers are added. The austenitic nitrogen-containing steel melted according to the AT-PS is characterized by a low porosity. However, it has been shown that such a steel cannot be reduced to yield strength values above 1600 N / mm² by cold reduction with degrees of deformation above 50%. Experiments have shown that the material breaks at higher degrees of cold reduction, for example when drawing starting material into thin wire cross sections. Porosity in the micro range was also observed. Apart from these metallurgical difficulties, such a steel is very expensive for large-scale use due to its high chromium and manganese content.
Wie in der AT-PS weiterhin ausgeführt, ist es zwar möglich, die nachteilige Porosität durch ein Erschmelzen der hier in Rede stehenden Chrom-Mangan-Stickstoff-Stähle unter erhöhtem Druck weitgehend zu verhindern. Bei diesen bekannten Verfahren können jedoch nur Maximalstickstoffgehalte von 0,8 Gew.-% erzielt werden. Diese Stickstoffgehalte reichen jedoch nicht aus, um Festigkeitswerte größer 1600 N/mm² zu erzielen.As further stated in the AT-PS, it is possible to largely prevent the disadvantageous porosity by melting the chrome-manganese-nitrogen steels in question here under increased pressure. With these known methods, however, only a maximum nitrogen content of 0.8% by weight can be achieved. However, these nitrogen contents are not sufficient to achieve strength values greater than 1600 N / mm².
Weiterhin ist es aus der AT-PS 266 900 bekannt, austenitische Stähle mit 0,02 bis 0,55 % C, bis 2 % Si, bis 20 % Mn, 0 bis 30 % Cr, 0 bis 25 % Ni, 0 bis 5 % Mo und/oder V und mehr als 0,5 %, vorzugsweise mindestens 1,4 % Stickstoff, die in Stickstoffatmosphäre unter Druck erschmolzen wurden, zur Herstellung von bewegten, insbesondere schwingend beanspruchten Maschinenteilen zu verwenden.It is also known from AT-PS 266 900, austenitic steels with 0.02 to 0.55% C, up to 2% Si, up to 20% Mn, 0 to 30% Cr, 0 to 25% Ni, 0 to 5 % Mo and / or V and more than 0.5%, preferably at least 1.4% nitrogen, which were melted under pressure in a nitrogen atmosphere, for the production of agitated, in particular to use machine parts subject to vibrations.
Diese bekannten Stähle sollen im abgeschreckten Zustand Dauerfestigkeiten bis 100 kp/mm² erreichen.These known steels are said to achieve fatigue strengths of up to 100 kp / mm² in the quenched state.
Nach dem aus der EP-A-0 249 117 bekannten Verfahren zur Herstellung von korrosionsbeständigem austenitischen Stahl aus 0.4 % C, 12-20 % Cr, 13-25 % Mn, 0.3-1 % N, 2 % Si, Rest Eisen und Verunreinigungen werden vornehmlich Halteringe für einen Generator erzeugt. Unter anderem kann die Erzeugung das Herstellen von Blöcken nach dem Elektro-Schlacke-Umschmelzen unter erhöhtem Druck mit Zugabe von Stickstoffträgern oder Einleiten von Stickstoffgas umfassen, ferner das Schmieden und Lösungsglühen. Danach schließt sich ein Abschrecken in Wasser und eine einachsige Kaltverarbeitung an. Ein Spannungsfreiglühen bei 350 °C für 2 Stunden schließt das Erzeugungsverfahren des Ausgangsmaterials für die Erzeugung der Ringe ab. Die genannte Schrift offenbart, daß hochchrom-, mangan- und stickstoffhaltige Stähle ausgezeichnete Spaltkorrosionsbeständigkeit aufweisen. Über die erzielbaren Festigkeitswerte ist dieser Schrift allerdings nichts zu entnehmen. Generell weiß der Fachmann, z.B. aus der FR-A-2 493 344, daß z.B. bei nicht-magnetischen Kappenringen auch hohe Anforderungen an die mechanischen Eigenschaften gestellt werden. Allerdings wird hier nicht gesagt, wie man dieses Ziel erreicht.According to the process known from EP-A-0 249 117 for the production of corrosion-resistant austenitic steel from 0.4% C, 12-20% Cr, 13-25% Mn, 0.3-1% N, 2% Si, remainder iron and impurities retaining rings for a generator are primarily produced. Among other things, the production can include the production of blocks after the electro-slag remelting under increased pressure with the addition of nitrogen carriers or the introduction of nitrogen gas, as well as forging and solution annealing. This is followed by quenching in water and uniaxial cold processing. Stress relief annealing at 350 ° C for 2 hours completes the production process of the starting material for the production of the rings. The cited document discloses that high-chromium, manganese and nitrogen-containing steels have excellent crevice corrosion resistance. This document, however, does not reveal anything about the achievable strength values. In general, the expert knows, e.g. from FR-A-2 493 344 that e.g. With non-magnetic cap rings, high demands are also placed on the mechanical properties. However, it does not say how to achieve this goal.
Aufgabe der Erfindung ist die Erzeugung hochfester korrosionsbeständiger Verbindungselemente. Dabei sollen sich die Stähle der erfindungsgemäßen Art nahezu unbegrenzt kaltverformen lassen. Sie sollen dazu von relativ hohen Ausgangsquerschnitten bis zu dünnsten Abmessungen ohne Bruchgefahr heruntergearbeitet werden können.The object of the invention is to produce high-strength, corrosion-resistant connecting elements. The steels of the type according to the invention should be able to be cold worked almost indefinitely. For this purpose, they should be able to be machined from relatively high initial cross sections to the thinnest dimensions without the risk of breakage.
Es hat sich gezeigt, daß die Analyseneinstellung im beanspruchten Bereich in Verbindung mit dem an sich bekannten Druckelektroschlackeumschmelzverfahren und der nach dem Kaltumformen erfolgenden Auslagerung zu höchsten Streckgrenzenwerten über 1800 N/mm² führt. Dabei ist der Stahl gleichzeitig auch porenfrei. Verformungsgrade (=Ausgangsquerschnitt-Endquerschnitt:Ausgangsquerschnittx100 %) bis 90 % sind möglich, weil die hohen Streckgrenzenwerte erst nach dem abschließenden Auslagern erzielt werden.It has been shown that the analysis setting in the claimed range in connection with the known pressure electro-slag remelting process and the aging after cold forming leads to the highest yield strength values over 1800 N / mm². The steel is also non-porous at the same time. Degrees of deformation (= final cross-sectional area: final cross-section x100%) up to 90% are possible because the high yield strength values are only achieved after the final outsourcing.
Mit dem erfindungsgemäßen Verfahren gemaß Anspruch 1 lassen sich die geforderten Streckgrenzenwerte von größer 1800 N/mm² mit Sicherheit erreichen, insbesondere durch das erfindungsgemäß vorgesehene Auslagern des mit höchsten Querschnittsabnahmen vorverformten Endprodukts bei Temperaturen von 300 bis 500 °C für eine dem Querschnitt angepaßte Zeit von 20 Minuten bis 5 Stunden. Diese Auslagerungsbehandlung bedingt eine Umordnung der bei den vorherigen Kaltverformungsvorgängen gebildeten Versetzungen innerhalb des Stahls, und zwar ohne Änderung der sog. Versetzungsdichte, die letztendlich für die hohe Festigkeit dieser Stähle verantwortlich ist. Beim späteren Einsatz der erfindungsgemäß hergestellten Stähle als Verbindungselemente, wie Bolzen, Schrauben, Nägel oder als Drahtseile, bedingt die so geschaffene innere Struktur der Stähle, daß zur weiteren Verformung sehr hohe innere Spannungen aufgewendet werden müssen. Das bedeutet aber, daß die Stähle bei ihrem späteren Einsatz höchsten Belastungen gewachsen sind.With the method according to the invention according to claim 1, the required yield strength values of greater than 1800 N / mm² can be achieved with certainty, in particular by the outsourcing of the end product preformed with the highest cross-sectional decreases at temperatures of 300 to 500 ° C for a time of 20 times adapted to the cross section Minutes to 5 hours. This aging treatment results in a rearrangement of the dislocations within the steel formed during the previous cold-forming processes, and without changing the so-called dislocation density, which is ultimately responsible for the high strength of these steels. Later use The steels produced according to the invention as connecting elements, such as bolts, screws, nails or as wire ropes, result in the inner structure of the steels thus created that very high internal stresses have to be used for further deformation. However, this means that the steels can withstand the highest loads when they are used later.
Eine eigenständige Variante zur Lösung des erfindungsgemäßen Problems besteht in dem Einsatz von Pulver anstelle eines Gußprodukts als Ausgangsmaterial gemäß Anspruch 2. Das Metallpulver wird durch heißisostatisches Verpressen zu einem Vorblock geformt, der dann zu einem Vorprodukt von 5 bis 150 mm Durchmesser umgeschmiedet und/oder ausgewalzt wird, das Vorprodukt dann mit einer Querschnittsabnahme von mindestens 60 % zu einem Endprodukt mit 0,5 bis 90 mm Durchmesser kaltverformt wird und anschließend das Endprodukt bei Temperaturen von 300 bis 500 °C für eine Zeit von 20 Minuten bis 5 Stunden ausgelagert wird.An independent variant for solving the problem according to the invention consists in the use of powder instead of a cast product as the starting material according to claim 2. The metal powder is shaped by hot isostatic pressing into a billet, which is then forged and / or rolled out to a billet of 5 to 150 mm in diameter is, the preliminary product is then cold-formed with a cross-sectional decrease of at least 60% to an end product with a diameter of 0.5 to 90 mm and then the end product is aged at temperatures of 300 to 500 ° C for a period of 20 minutes to 5 hours.
Die abhängigen Ansprüche 3 bis 6 betreffen bevorzugte Ausführungsformen des Verfahrens nach Anspruch 1 oder 2.The dependent claims 3 to 6 relate to preferred embodiments of the method according to claim 1 or 2.
Die Herstellung des Stahls auf pulvermetallurgischem Wege bietet eine ausgezeichnete Garantie für einen hervorragenden Reinheitsgrad und das Nichtvorliegen von Porosität.The production of the steel by powder metallurgy offers an excellent guarantee for an excellent degree of purity and the absence of porosity.
Bevorzugt werden nach dem erfindungsgemäßen Verfahren Bolzen, Schrauben, Nägel, sowie Drahtseile, erzeugt.Bolts, screws, nails and wire ropes are preferably produced by the method according to the invention.
Anhand der folgenden Beispiele wird die Erfindung erläutert.The invention is illustrated by the following examples.
In einem Druckelektroschlackeumschmelzofen wurde eine Elektrode der folgenden Zusammensetzung (in Masse-%)
Der im Druckelektroschlackeumschmelzofen erstarrte Stahlblock mit der obigen Gesamtanalyse wurde dann durch Schmieden und Walzen auf einen Querschnitt von 7 mm Durchmesser gebracht. In 8 Zügen wurde der Durchmesser von 7 mm auf 3 mm kaltgezogen. Dies entspricht einer Gesamtverformung von 82 % (ca. 10 % Kaltverformung pro Zug).The steel block solidified in the pressure electro-slag remelting furnace with the above overall analysis was then brought to a cross-section of 7 mm in diameter by forging and rolling. The diameter was cold drawn from 7 mm to 3 mm in 8 passes. This corresponds to a total deformation of 82% (approx. 10% cold deformation per train).
Nach einer Zwischenglühung bei 1080 °C wurde der Draht weiter kaltgezogen vom Durchmesser 3 mm auf 1,8 mm. Die Gesamtumformung betrug dabei 64 % in 6 Zügen (ca. 10 % Verformung pro Zug). Anschließend wurde der auf 1,8 mm Durchmesser gezogene Draht bei einer Temperatur von 400 °C für 4 Stunden ausgelagert.After intermediate annealing at 1080 ° C, the wire was further cold drawn from a diameter of 3 mm to 1.8 mm. The total deformation was 64% in 6 moves (approx. 10% deformation per move). The wire drawn to 1.8 mm in diameter was then aged at a temperature of 400 ° C. for 4 hours.
Danach wurde eine Streckgrenze von Rp = 2400 N/mm², eine Zugfestigkeit Rm von 2550 N/mm², ein Dehnung A = 6,1 % und eine Brucheinschnürung Z von 48,3 % im Rahmen des üblichen Zugversuches ermittelt.Then a yield strength of Rp = 2400 N / mm², a tensile strength Rm of 2550 N / mm², an elongation A = 6.1% and a fracture necking Z of 48.3% were determined in the course of the usual tensile test.
Die entsprechenden Werte vor der Auslagerungsbehandlung betrugen für die Streckgrenze 2100 N/mm² , für die Zugfestigkeit 2220 N/mm² , für die Dehnung 6 % und für die Brucheinschnürung 46 %.The corresponding values before the aging treatment were 2100 N / mm² for the yield strength, 2220 N / mm² for the tensile strength, 6% for the elongation and 46% for the fracture constriction.
Daraus erhellt, daß in bezug auf die gewünschte Steigerung der Festigkeitswerte der erfindungsgemäßen Auslagerungsbehandlung ein hoher Stellenwert beizumessen ist. Gelingt es doch mit dieser Auslagerungsbehandlung, Streckgrenzen- und Zugfestigkeitswerte einzustellen, wie sie bisher noch nicht bekannt waren. Dabei ist insbesondere überraschend, daß die Werte für die Zähigkeit, hier ausgedrückt durch die Dehnung und die Brucheinschnürung, konstant bleiben.It is evident from this that, in relation to the desired increase in the strength values, the aging treatment according to the invention is of high importance. With this aging treatment it is possible to set yield strengths and tensile strength values that were previously unknown. It is particularly surprising that the values for the toughness, expressed here by the elongation and the fracture constriction, remain constant.
Es hat sich weiterhin bei den Versuchen gezeigt, daß auch bei sehr hohen Kaltverformungsgraden das austenitische Gefüge durch den hohen Stickstoffgehalt und den hohen Reinheitsgrad so stabilisiert ist, daß ein Umklappen des Austenits in Martensit nicht auftrat. Damit können die bisher bei austenitischen Stählen beobachteten schädlichen Wirkungen des sog. Verformungs-Martensits vermieden werden, insbesondere ein Abfall der Zähigkeit, was ein Ende der Kaltziehfähigkeit bedeutet.It has also been shown in the tests that, even at very high degrees of cold deformation, the austenitic structure is so stabilized by the high nitrogen content and the high degree of purity that the austenite did not fold over into martensite. The harmful effects of the so-called deformation martensite previously observed in austenitic steels can thus be avoided, in particular a drop in toughness, which means an end to the cold drawing ability.
Ferner bleiben die Stähle auch bei höchsten Verformungsgraden unmagnetisch. Außerdem wird die Anfälligkeit gegen Spannungsrißkorrosion in verdünnten wässrigen Lösungen bis 80 °C verringert.Furthermore, the steels remain non-magnetic even at the highest degrees of deformation. It also reduces susceptibility to stress corrosion cracking in dilute aqueous solutions up to 80 ° C.
Claims (6)
- A process for the production of connecting elements, more particularly pins, screws, nails or wire ropes having a minimum yield point of 1800 N/mm² from a fully austenitic chromium-manganese steel having (in % by weight):
max 0.12 % C
0.20 to 1.00 % Si
17.5 to 20.0 % Mn
max 0.05 % P
max 0.015% S
17.5 to 20.0 % Cr
max 5.0 % Mo
max 3.0 % Ni
0.8 to 1.2 % N
residue iron and the usual impurities due to melting, wherein an electrode is produced for electroslag remelting, in a pressure electroslag remelting process during the melting of said electrode the nitrogen content of the steel is adjusted by the addition of nitrogen-containing materials, the steel block, solidified under pressure, is then forged and/or rolled out into a preliminary product 5 to 150 mm in diameter, said preliminary product is then cold worked with a total cross-sectional reduction of at least 60% to a final product having a diameter of 0.5 to 90 mm, whereafter the final product is aged for 20 minutes to 5 hours at temperatures of 300 to 500°C. - A process for the production of connecting elements, more particularly pins, screws, nails or wire ropes having a minimum yield point of 1800 N/mm² from a fully austenitic chromium-manganese steel having (in % by weight):
max 0.12 % C
0.20 to 1.00 % Si
17.5 to 20.0 % Mn
max 0.05 % P
max 0.015% S
17.5 to 20.0 % Cr
max 5.0 % Mo
max 3.0 % Ni
0.8 to 1.2 % N
residue iron and the usual impurities due to melting, wherein a metal powder produced, the nitrogen content is adjusted by increasing the nitrogen content in the solid phase, the metal powder is shaped by hot isostatic pressing into a preliminary block, said preliminary block is then forged and/or rolled out into a preliminary product 5 to 150 mm in diameter, said preliminary product is then cold worked with a total cross-sectional reduction of at least 60% to a final product having a diameter of 0.5 to 90 mm, whereafter the final product is aged for 20 minutes to 5 hours at temperatures of 300 to 500°C. - A process according to claims 1 or 2, characterized in that the preliminary product is cold worked by stretching.
- A process according to claims 1 or 2, characterized in that the preliminary product is cold worked by drawing.
- A process according to claim 4, characterized in that the drawing is performed in a number of component steps.
- A process according to claims 4 or 5, characterized in that following the first drawing step an intermediate annealing is performed at temperatures of 1000 to 1150°C.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3940438 | 1989-12-07 | ||
| DE3940438A DE3940438C1 (en) | 1989-12-07 | 1989-12-07 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0432434A1 EP0432434A1 (en) | 1991-06-19 |
| EP0432434B1 true EP0432434B1 (en) | 1994-09-21 |
Family
ID=6394974
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP90120990A Expired - Lifetime EP0432434B1 (en) | 1989-12-07 | 1990-11-02 | Process for manufacturing joining structural parts from a fully austenitic Cr-Mn steel. |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0432434B1 (en) |
| JP (1) | JPH0688160A (en) |
| AT (1) | ATE111968T1 (en) |
| DE (2) | DE3940438C1 (en) |
Families Citing this family (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19607828C2 (en) * | 1995-04-15 | 2003-06-18 | Vsg En Und Schmiedetechnik Gmb | Process for producing an austenitic Cv-Mn steel |
| DE19648335C2 (en) | 1996-11-22 | 2000-05-25 | Daimler Chrysler Ag | Arrangement for position measurement |
| DE19758613C2 (en) * | 1997-04-22 | 2000-12-07 | Krupp Vdm Gmbh | High-strength and corrosion-resistant iron-manganese-chrome alloy |
| EP0918099A1 (en) * | 1997-10-27 | 1999-05-26 | Stahlwerk Ergste Westig GmbH | Chrome-manganese steel alloy |
| SE508814C2 (en) | 1997-12-17 | 1998-11-09 | Haldex Garphyttan Ab | Ways to make cold drawn wire of ESR remelted stainless steel and cold drawn wire |
| CH694401A5 (en) | 1999-05-26 | 2004-12-31 | Basf Ag | Low-nickel, low-molybdenum, biocompatible, non-allergenic, corrosion-resistant austenitic steel. |
| CN1495281A (en) | 1999-06-24 | 2004-05-12 | Basf | Application of low-nickel austenite steel |
| 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 |
| AT8763U1 (en) * | 2005-12-06 | 2006-12-15 | Teufelberger Seil Ges M B H | LINEAR POWER TRANSMISSION ELEMENT, ESPECIALLY WIRE BZW. COMBINATION OF WIRES |
| 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 |
| JP5858424B2 (en) * | 2011-12-01 | 2016-02-10 | 株式会社日本製鋼所 | Stainless steel for polymer electrolyte fuel cell separator and method for producing the same |
| CN102719682B (en) * | 2012-02-14 | 2014-05-21 | 攀钢集团江油长城特殊钢有限公司 | Smelting method of GH901 alloy |
| CN106834951A (en) * | 2014-06-11 | 2017-06-13 | 丹阳市凯鑫合金材料有限公司 | A kind of resonant rod of RF device invar cold-heading silk |
| JP6640654B2 (en) * | 2016-05-30 | 2020-02-05 | 株式会社東芝 | Manufacturing method of high Cr steel parts |
| DE102017116615B3 (en) | 2017-07-24 | 2018-08-30 | Benteler Steel/Tube Gmbh | Piston cylinder system with at least one pipe element |
| CN111500942B (en) * | 2020-05-11 | 2021-08-10 | 湖南恒基粉末科技有限责任公司 | High-nitrogen-content non-magnetic stainless steel powder and preparation method thereof |
| CN112719794B (en) * | 2020-12-16 | 2022-03-11 | 浙江福尔加机械股份有限公司 | Machining method of automobile hub bolt |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2745740A (en) * | 1954-09-02 | 1956-05-15 | Ford Motor Co | Process of preparing an iron base melt |
| US2783169A (en) * | 1955-02-15 | 1957-02-26 | Ford Motor Co | Process of producing nitrogen rich wrought austenitic alloys |
| AT266900B (en) * | 1963-05-24 | 1968-12-10 | Boehler & Co Ag Geb | Austenitic non-magnetizable steels for the production of moving machine parts, especially machine parts subject to vibrations |
| US3820980A (en) * | 1972-05-08 | 1974-06-28 | Allegheny Ludlum Ind Inc | Austenitic stainless steel |
| US3936297A (en) * | 1972-05-08 | 1976-02-03 | Allegheny Ludlum Industries, Inc. | Method of producing austenitic stainless steel |
| US3912503A (en) * | 1973-05-14 | 1975-10-14 | Armco Steel Corp | Galling resistant austenitic stainless steel |
| DE2528588C2 (en) * | 1974-06-27 | 1990-05-10 | Inteco Internationale Technische Beratung GmbH, Bruck an der Mur | Process for the large-scale production of austenitic steels or alloys with nitrogen contents above the maximum solubility at atmospheric pressure |
| 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 |
-
1989
- 1989-12-07 DE DE3940438A patent/DE3940438C1/de not_active Expired - Lifetime
-
1990
- 1990-11-02 DE DE59007249T patent/DE59007249D1/en not_active Expired - Lifetime
- 1990-11-02 EP EP90120990A patent/EP0432434B1/en not_active Expired - Lifetime
- 1990-11-02 AT AT90120990T patent/ATE111968T1/en not_active IP Right Cessation
- 1990-12-07 JP JP2414160A patent/JPH0688160A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| EP0432434A1 (en) | 1991-06-19 |
| JPH0688160A (en) | 1994-03-29 |
| DE59007249D1 (en) | 1994-10-27 |
| DE3940438C1 (en) | 1991-05-23 |
| ATE111968T1 (en) | 1994-10-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP0432434B1 (en) | Process for manufacturing joining structural parts from a fully austenitic Cr-Mn steel. | |
| DE60016369T2 (en) | COLD WORKABLE STEEL WIRE OR STEEL STICK AND METHOD | |
| DE1508416C3 (en) | Process for the production of steel parts such as bolts, screws, pins and the like. | |
| DE102005052069B4 (en) | Process for the production of semi-finished steel by hot working | |
| DE1558668C3 (en) | Use of creep-resistant, stainless austenitic steels for the production of sheet metal | |
| EP2111475A1 (en) | Components made of steels with an ultrahigh carbon content and with a reduced density and high scaling resistance | |
| EP1420077B1 (en) | Inert material with high hardness for elements used at high temperature | |
| DE1483218B2 (en) | Process for producing a heat-resistant, ferritic Cr-Mo-V steel with high creep strength and improved creep elongation | |
| DE102008040689B4 (en) | Ball studs and sleeves made of high manganese steel | |
| EP0315576B1 (en) | Procedure for the fabrication of cladstell plates | |
| DE19546204C1 (en) | High strength steel object prodn.,esp. leaf spring | |
| EP2183396B1 (en) | Steel for producing machine components formed from solid stock | |
| DE1558687A1 (en) | Process for improving the strength and elongation of steel | |
| DE3730379C2 (en) | ||
| DE1290727B (en) | Process for the production of high strength niobium alloys | |
| EP0367360B1 (en) | Process for manufacturing seamless pressure vessels | |
| DE1458359B2 (en) | USING A STEEL ALLOY AS HIGH-STRENGTH TURNING RUST-RESISTANT STRUCTURAL STEEL | |
| EP3458623B1 (en) | Method for producing a steel material, and steel material | |
| DE3136722C2 (en) | Process for the production of valves for internal combustion engines | |
| DE3507124A1 (en) | Oil-drilling pipe welded by electric resistance welding, and method for the manufacture thereof | |
| DE19921286A1 (en) | Heat treatment process for the production of surface-hardened long and flat products from unalloyed or low-alloy steels | |
| EP3122910A2 (en) | Components made of a steel alloy and method for producing high-strength components | |
| DE2225517B2 (en) | METHOD FOR MANUFACTURING A BEARING ELEMENT | |
| DE1807992B2 (en) | Heat treatment process to achieve a bainitic structure in a high-strength steel | |
| EP2628807A1 (en) | Tempered pin-shaped connection element and method for producing same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE |
|
| 17P | Request for examination filed |
Effective date: 19910523 |
|
| 17Q | First examination report despatched |
Effective date: 19930729 |
|
| GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
| AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH DE DK ES FR GB IT LI LU NL SE |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Effective date: 19940921 Ref country code: ES Free format text: THE PATENT HAS BEEN ANNULLED BY A DECISION OF A NATIONAL AUTHORITY Effective date: 19940921 Ref country code: BE Effective date: 19940921 Ref country code: DK Effective date: 19940921 |
|
| REF | Corresponds to: |
Ref document number: 111968 Country of ref document: AT Date of ref document: 19941015 Kind code of ref document: T |
|
| GBT | Gb: translation of ep patent filed (gb section 77(6)(a)/1977) |
Effective date: 19940928 |
|
| REF | Corresponds to: |
Ref document number: 59007249 Country of ref document: DE Date of ref document: 19941027 |
|
| ITF | It: translation for a ep patent filed |
Owner name: SOCIETA' ITALIANA BREVETTI S.P.A. |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19941130 |
|
| EAL | Se: european patent in force in sweden |
Ref document number: 90120990.8 |
|
| ET | Fr: translation filed | ||
| NLV1 | Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act | ||
| PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
| 26N | No opposition filed | ||
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20011030 Year of fee payment: 12 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 20011107 Year of fee payment: 12 |
|
| REG | Reference to a national code |
Ref country code: GB Ref legal event code: IF02 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20021102 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 20021111 Year of fee payment: 13 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20021130 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20021130 |
|
| GBPC | Gb: european patent ceased through non-payment of renewal fee | ||
| REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20031103 |
|
| EUG | Se: european patent has lapsed | ||
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: AT Payment date: 20091130 Year of fee payment: 20 Ref country code: DE Payment date: 20091124 Year of fee payment: 20 |
|
| PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20091126 Year of fee payment: 20 Ref country code: FR Payment date: 20091203 Year of fee payment: 20 |
|
| PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF EXPIRATION OF PROTECTION Effective date: 20101102 |