EP0279300A2 - Cast iron for the manufacture of brake drums - Google Patents
Cast iron for the manufacture of brake drums Download PDFInfo
- Publication number
- EP0279300A2 EP0279300A2 EP88101722A EP88101722A EP0279300A2 EP 0279300 A2 EP0279300 A2 EP 0279300A2 EP 88101722 A EP88101722 A EP 88101722A EP 88101722 A EP88101722 A EP 88101722A EP 0279300 A2 EP0279300 A2 EP 0279300A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- cast iron
- less
- brake
- molybdenum
- manganese
- 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.)
- Granted
Links
- 229910001018 Cast iron Inorganic materials 0.000 title claims abstract description 15
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 11
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910052750 molybdenum Inorganic materials 0.000 claims abstract description 9
- 239000011733 molybdenum Substances 0.000 claims abstract description 9
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 8
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910052802 copper Inorganic materials 0.000 claims abstract description 7
- 239000010949 copper Substances 0.000 claims abstract description 7
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 claims abstract description 6
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims abstract description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 6
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 6
- 229910052748 manganese Inorganic materials 0.000 claims abstract description 6
- 239000011572 manganese Substances 0.000 claims abstract description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims abstract description 6
- 239000011574 phosphorus Substances 0.000 claims abstract description 6
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 6
- 239000010703 silicon Substances 0.000 claims abstract description 6
- 229910000859 α-Fe Inorganic materials 0.000 claims abstract description 6
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 5
- 239000011651 chromium Substances 0.000 claims abstract description 5
- 239000000203 mixture Substances 0.000 claims abstract description 4
- 239000000126 substance Substances 0.000 claims abstract description 4
- 229910045601 alloy Inorganic materials 0.000 claims description 7
- 239000000956 alloy Substances 0.000 claims description 7
- 238000010438 heat treatment Methods 0.000 claims description 6
- 238000000137 annealing Methods 0.000 claims description 5
- 238000000034 method Methods 0.000 claims description 5
- 229910052717 sulfur Inorganic materials 0.000 claims description 5
- 239000011593 sulfur Substances 0.000 claims description 5
- 239000005864 Sulphur Substances 0.000 abstract 1
- 239000007787 solid Substances 0.000 abstract 1
- 230000035882 stress Effects 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910001060 Gray iron Inorganic materials 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 230000032683 aging Effects 0.000 description 1
- 238000005275 alloying Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000018109 developmental process Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000029142 excretion Effects 0.000 description 1
- 230000017525 heat dissipation Effects 0.000 description 1
- 238000011081 inoculation Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910001562 pearlite Inorganic materials 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- CADICXFYUNYKGD-UHFFFAOYSA-N sulfanylidenemanganese Chemical compound [Mn]=S CADICXFYUNYKGD-UHFFFAOYSA-N 0.000 description 1
- 238000002255 vaccination Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B5/00—Making pig-iron in the blast furnace
- C21B5/02—Making special pig-iron, e.g. by applying additives, e.g. oxides of other metals
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C37/00—Cast-iron alloys
- C22C37/06—Cast-iron alloys containing chromium
Definitions
- the invention relates to a cast iron for the production of brake drums, massive and ventilated brake discs and other brake bodies with an alloy of over 3.6% carbon 0.6-0.9% manganese 1.8 - 2.5% silicon less than 0.1% phosphorus less than 0.12% sulfur and with minor components of chrome, molybdenum and copper, the cast iron has a pearlitic structure.
- a cast iron with this chemical composition is described in DE-OS 33 05 184. Due to the development of new asbestos-free brake pads, it became necessary to use cast iron alloys for brake drums, brake disks and the like that can withstand higher temperatures. To this end, the general tendency among users has hitherto been to use highly heat-resistant types of iron with a higher carbon content, which, however, have disadvantages, particularly with regard to a coarse structure and strength.
- the present invention is therefore based on the object of providing a cast iron of the type mentioned at the outset, which has the lowest possible ferrite content with high tensile strength.
- this object is achieved by the combination of the following features, namely a pearlitic basic structure with a maximum of 5% ferrite content and a tensile strength of at least 200 N / mm2 with the following chemical composition: Carbon 3.62 - 3.68% Silicon max. 2.10% Manganese 0.70 - 0.85% Phosphorus less than 0.080% Sulfur less than 0.095% Chromium 0.18 - 0.25% Molybdenum 0.30 - 0.45% Copper 0.30 - 0.45%.
- the specified alloy components such as chromium, molybdenum, manganese and copper, determined in long tests, achieve a tensile strength of at least 200 N / mm2.
- molybdenum In combination with chrome, molybdenum also ensures a high core strength of the structure and, as an alloy component, gives good heat resistance with changing thermal loads on the brake discs.
- the carbon content up to max. 3.68% is achieved by melting in the cupola furnace at the C level of 3.4 - 3.45%.
- the remaining 0.25 - 0.30% are introduced into the ladle using electrode graphite when tapping the liquid iron using a special vaccination process.
- the resulting optimal inoculation effect gives rise to A-graphite of size 3-4. It was surprisingly found that carbide deposits in the pearlitic structure despite their alloying elements such as chromium and molybdenum do not occur.
- the high carbon content causes a lot of graphite excretion with its excellent thermal conductivity and high thermal resistance properties for brakes. This means that the heat build-up on the brake friction rings can be spread over the entire disc in a very short time, which significantly reduces thermal stresses and fire cracks.
- Sulfur is used up to a maximum of 0.095% to achieve the manganese Sulfur ratio used, but should not exceed the specified value.
- the cast iron according to the invention has a fine structure and the graphite lamellae become somewhat shorter, as a result of which the higher strength according to the invention can be achieved.
- a high proportion of carbon counteracts this, i.e. causes a reduction in strength and a coarser structure.
- a high carbon content is a cost factor.
- a low carbon content can be used, in the range of 3.62 - 3.68%, if this is done with the other alloy components combined. In this case, the desired high strength values and heat resistance are achieved.
- the parts to be treated are brought to a temperature of 650-720 degrees C. in a heating-up time of 180 minutes and then kept at this temperature for 30 minutes, after which slow cooling in the annealing furnace to 250 degrees C.
- the parts Before annealing, the parts should be pre-processed, namely roughed.
- the cast skin of the friction surface and the inside of the pot should be removed approx. 1.5 mm.
- the subsequent post-treatment method according to the invention eliminates both internal stresses generated during the cooling process and stresses caused by the machining. It is also essential that, due to the increased strength achieved by the alloy components in a certain area, higher residual stresses can arise, which can be eliminated by the heat treatment process according to the invention.
- the longer heating time specified for the heating of the parts to be treated prevents their warping.
- the cooling down after the specified holding time should in any case be carried out slowly so that no new tensions arise. This can e.g. can be achieved in a simple manner by switching off the annealing furnace, the parts remaining in the slowly cooling annealing furnace for a relatively long time.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Braking Arrangements (AREA)
- Heat Treatment Of Articles (AREA)
Abstract
Description
Die Erfindung betrifft ein Gußeisen zur Fertigung von Bremstrommeln, von massiven und belüfteten Bremsscheiben und sonstigen Bremsenkörpern mit einer Legierung von
über 3,6 % Kohlenstoff
0,6 - 0,9 % Mangan
1,8 - 2,5 % Silizium
weniger als 0,1 % Phosphor
weniger als 0,12 % Schwefel
und mit geringen Bestandteilen von Chrom, Molybdän und Kupfer,
wobei das Gußeisen ein perlitisches Grundgefüge aufweist.The invention relates to a cast iron for the production of brake drums, massive and ventilated brake discs and other brake bodies with an alloy of
over 3.6% carbon
0.6-0.9% manganese
1.8 - 2.5% silicon
less than 0.1% phosphorus
less than 0.12% sulfur
and with minor components of chrome, molybdenum and copper,
the cast iron has a pearlitic structure.
Ein Gußeisen mit dieser chemischen Zusammensetzung ist in der DE-OS 33 05 184 beschrieben. Aufgrund der Entwicklung von neuen asbestfreien Bremsbelägen wurde es notwendig auch Gußeisenlegierungen bei Bremstrommeln, Bremsscheiben und dgl. zu verwenden, die höhere Temperaturen ertragen. Hierzu ging die allgemeine Tendenz bei den Anwendern bisher dahin, hoch warmfeste Eisensorten mit höherem Kohlenstoffgehalt zu verwenden, die jedoch Nachteile aufweisen, insbesondere bezüglich einem groben Gefüge und der Festigkeit.A cast iron with this chemical composition is described in DE-OS 33 05 184. Due to the development of new asbestos-free brake pads, it became necessary to use cast iron alloys for brake drums, brake disks and the like that can withstand higher temperatures. To this end, the general tendency among users has hitherto been to use highly heat-resistant types of iron with a higher carbon content, which, however, have disadvantages, particularly with regard to a coarse structure and strength.
Gemäß der DE-OS 33 05 184 wird ein Werkstoff für Bremsenkörper vorgeschlagen, der einerseits eine ausreichende Festigkeit aufweisen soll, andererseits jedoch auch eine gute Wärmeableitung und eine hohe Dämpfungseigenschaft. In dieser Druckschrift wurde angegeben, daß auch bei niederen Festigkeitswerten die Warmzugfestigkeit bei extrem hohen Temperaturen von GG 30 nur geringfügig höher bzw. fast gleich derjenigen von GG 15 ist. Der Grauguß mit der relativ niedrigen Festigkeit soll ferner geringere Eigenspannungen besitzen, sich wegen des hohen C-Gehaltes bei der Bearbeitung weniger aufheizen und geringere Verzugserscheinigungen bei thermischer Belastung aufweisen als der bisher verwandte Grauguß mit hoher Festigkeit.According to DE-OS 33 05 184, a material for brake bodies is proposed which, on the one hand, should have sufficient strength, but, on the other hand, also has good heat dissipation and high damping properties. In this publication it was stated that, even at low strength values, the hot tensile strength at extremely high temperatures of GG 30 is only slightly higher or almost the same as that of GG 15. The gray cast iron with the relatively low strength is also said to have lower residual stresses, to heat up less during processing due to the high C content and to show less distortion under thermal stress than the previously used gray cast iron with high strength.
In der Praxis hat sich nun jedoch gezeigt, daß dieser Grau guß in nicht unerheblichen Mengen Ferritanteile aufweist. Ferritanteile in der Bremstrommel haben jedoch den Nachteil, daß die Reibpaarung, d.h. der Reibungskoeffizient zwischen den Bremsbelägen und der Bremstrommel bzw. Bremsscheibe sich verändert. Dies bedeutet, daß die Verzögerung beim Bremsen geringer wird. Optimal wäre somit ein möglichst 100%iges perlitisches Gefüge.In practice, however, it has now been shown that this gray casting has not insignificant amounts of ferrite. However, ferrite components in the brake drum have the disadvantage that the friction pairing, ie the coefficient of friction between the brake pads and the brake drum or brake disc, changes. This means that the braking deceleration becomes smaller. A 100% pearlitic structure would be optimal.
Außerdem wurde festgestellt, daß in vielen Fällen die Zugfestigkeit dieses Gußeisens nicht ausreicht.It was also found that in many cases the tensile strength of this cast iron was insufficient.
Der vorliegenden Erfindung liegt daher die Aufgabe zugrunde ein Gußeisen der eingangs erwähnten Art zu schaffen, das möglichst geringe Ferritanteile bei hoher Zugfestigkeit besitzt.The present invention is therefore based on the object of providing a cast iron of the type mentioned at the outset, which has the lowest possible ferrite content with high tensile strength.
Erfindungsgemäß wird diese Aufgabe durch die Kombination folgender Merkmale gelöst, nämlich einem perlitischen Grundgefüge mit maximal 5% Ferritanteil und einer Zugfestigkeit von mind. 200 N/mm² mit folgender chemischer Zusammensetzung:
Kohlenstoff 3,62 - 3,68 %
Silizium max. 2,10 %
Mangan 0,70 - 0,85 %
Phosphor weniger als 0,080 %
Schwefel weniger als 0,095 %
Chrom 0,18 - 0,25 %
Molybdän 0,30 - 0,45 %
Kupfer 0,30 - 0,45 %.
According to the invention, this object is achieved by the combination of the following features, namely a pearlitic basic structure with a maximum of 5% ferrite content and a tensile strength of at least 200 N / mm² with the following chemical composition:
Carbon 3.62 - 3.68%
Silicon max. 2.10%
Manganese 0.70 - 0.85%
Phosphorus less than 0.080%
Sulfur less than 0.095%
Chromium 0.18 - 0.25%
Molybdenum 0.30 - 0.45%
Copper 0.30 - 0.45%.
Durch die angegebene und in langen Versuchen ermittelten Legierungsbestandteile, wie Chrom, Molybdän, Mangan und Kupfer wird eine Zugfestigkeit von mind. 200 N/mm² erreicht.The specified alloy components, such as chromium, molybdenum, manganese and copper, determined in long tests, achieve a tensile strength of at least 200 N / mm².
Zusätzlich wurde in überraschender Weise festgestellt, daß Kupfer und auch Molybdän stabilisierend auf den Perlit wirken und zwar ohne zu Carbidausscheidungen zu führen. Es wurde festgestellt, daß sich mit dem erfindungsgemäßen Gußeisen ein 100%iges perlitisches Grundgefüge erreichen läßt.In addition, it was surprisingly found that copper and also molybdenum have a stabilizing effect on the pearlite, and indeed without leading to carbide deposits. It was found that a 100% pearlitic basic structure can be achieved with the cast iron according to the invention.
Molybdän bewirkt weiterhin in Verbindung mit Chrom eine hohe Kernfestigkeit des Gefüges und gibt als Legierungsbestandteil gute Warmfestigkeiten bei wechselnder thermischer Belastung der Bremsscheiben. Der Kohlenstoffgehalt bis max. 3,68 % wird durch Erschmelzen im Kupolofen im C-Level von 3,4 - 3,45 % erreicht. Die restlichen 0,25 - 0,30 % werden durch ein Spezialimpfverfahren beim Abstich des Flüssigeisens in die Gießpfanne mittels Elektrodengraphit eingebracht. Der entstehende optimale Impfeffekt läßt durchweg A-Graphit der Größe 3-4 entstehen. Dabei wurde überraschenderweise festgestellt, daß Carbidausscheidungen im perlitischen Grundgefüge trotz deren Legierungselemente wie Chrom und Molybdän nicht vorkommen.In combination with chrome, molybdenum also ensures a high core strength of the structure and, as an alloy component, gives good heat resistance with changing thermal loads on the brake discs. The carbon content up to max. 3.68% is achieved by melting in the cupola furnace at the C level of 3.4 - 3.45%. The remaining 0.25 - 0.30% are introduced into the ladle using electrode graphite when tapping the liquid iron using a special vaccination process. The resulting optimal inoculation effect gives rise to A-graphite of size 3-4. It was surprisingly found that carbide deposits in the pearlitic structure despite their alloying elements such as chromium and molybdenum do not occur.
Der hohe Kohlenstoffgehalt bewirkt viel Graphitausscheidung mit seinen für Bremsen hervorragenden Eigenschaften der Wärmeleitfähigkeit und der hohen thermischen Beständigkeit. Dies bedeutet, daß der Hitzestau auf den Bremsreibringen in kürzester Zeit auf die gesamte Scheibe verteilt werden kann, wodurch thermische Spannungen und Brandrisse deutlich vermindert werden.The high carbon content causes a lot of graphite excretion with its excellent thermal conductivity and high thermal resistance properties for brakes. This means that the heat build-up on the brake friction rings can be spread over the entire disc in a very short time, which significantly reduces thermal stresses and fire cracks.
Von Vorteil ist auch, daß aufgrund fehlender Carbidausscheidungen in dem perlitischem Grundgefüge Brandflecken, Risse durch Ausdehnungsfehler an den Reibringoberflächen, sowie das Auftreten von Hotspots nicht entstehen. Das nachteilige Rubbeln der Scheiben bei den bisher verwendeten Materialien wird, soweit dies materialbedingt ist, durch das erfindungsgemäße Gußeisen ausgeschlossen.It is also advantageous that burn marks, cracks due to expansion errors on the friction ring surfaces and the occurrence of hot spots do not occur due to the lack of carbide precipitates in the pearlitic basic structure. The disadvantageous rubbing of the disks in the materials previously used is, as far as this is material-related, excluded by the cast iron according to the invention.
Da Silizium die Wärmeleitfähigkeit erheblich reduziert, darf ein Bestandteil von 2,1 % nicht überschritten werden, da diese Eigenschaft der gewünschten schnellen Wärmeverteilung in der Scheibe entgegenwirkt. Der angegebene Wert von 0,08 % für Phosphor darf nicht überschritten werden, um Steadit und damit harte Bestandteile im Grundgefüge zu verhindern.Since silicon significantly reduces the thermal conductivity, a component of 2.1% must not be exceeded, since this property counteracts the desired rapid heat distribution in the pane. The specified value of 0.08% for phosphorus must not be exceeded in order to prevent steadite and thus hard constituents in the basic structure.
Schwefel wird bis maximal 0,095 % zur Erreichung des Mangan- Schwefel-Verhältnisses gebraucht, sollte jedoch den angegebenen Wert nicht überschreiten.Sulfur is used up to a maximum of 0.095% to achieve the manganese Sulfur ratio used, but should not exceed the specified value.
Bei dem erfindungsgemäßen Gußeisen ergibt sich ein feines Gefüge und die Graphitlamellen werden etwas kürzer, wodurch die erfindungsgemäße höhere Festigkeit erreicht werden kann. Ein hoher Kohlenstoffanteil wirkt diesem an sich entgegen, d.h. bewirkt eine Festigkeitsverminderung und ein groberes Gefüge. Außerdem stellt ein hoher Kohlenstoffanteil einen Kostenfaktor dar. In langwierigen Versuchen wurde nun festgestellt, daß man entgegen der allgemeinen Meinung mit einem geringen Kohlenstoffgehalt auskommt und zwar in dem ermittelten Bereich von 3,62 - 3,68 %, wenn man dies mit den übrigen Legierungsbestandteilen kombiniert. In diesem Falle kommt man zu den gewünschten hohen Festigkeitswerten und der Wärmebeständigkeit.The cast iron according to the invention has a fine structure and the graphite lamellae become somewhat shorter, as a result of which the higher strength according to the invention can be achieved. A high proportion of carbon counteracts this, i.e. causes a reduction in strength and a coarser structure. In addition, a high carbon content is a cost factor. In lengthy tests, it has now been found that, contrary to popular belief, a low carbon content can be used, in the range of 3.62 - 3.68%, if this is done with the other alloy components combined. In this case, the desired high strength values and heat resistance are achieved.
Zur Entspannung der Gußteile (künstliches Altern) nach Ihrer Herstellung wird erfindungsgemäß eine an sich bekannte Wärmenachbehandlung vorgeschlagen, die in erfinderischer Weise an das erfindungsgemäße Gußeisen angepaßt worden ist.To relax the castings (artificial aging) after their manufacture, a heat treatment known per se is proposed according to the invention, which has been adapted in an inventive manner to the cast iron according to the invention.
Hierzu wird erfindungsgemäß vorgeschlagen, daß die zu behandelnden Teile in einer Aufheizzeit von 180 Minuten auf eine Temperatur von 650 - 720 Grad C gebracht und anschließend für 30 Minuten bei dieser Temperatur gehalten werden, wonach eine langsame Abkühlung im Glühofen auf 250 Grad C erfolgt.For this purpose, it is proposed according to the invention that the parts to be treated are brought to a temperature of 650-720 degrees C. in a heating-up time of 180 minutes and then kept at this temperature for 30 minutes, after which slow cooling in the annealing furnace to 250 degrees C.
Vor dem Glühen sollen die Teile vorbearbeitet, nämlich geschruppt, werden. Die Gußhaut der Reibfläche, sowie des Topfinnenbodens, sollte ca. 1,5 mm entfernt werden. Durch das anschließende erfindungsgemäße Wärmenachbehandlungsverfahren werden sowohl während der Abkühlung entstandene Eigenspannungen als auch Spannungen, die durch das Bearbeiten entstanden sind, eliminiert. Wesentlich dabei ist auch, daß aufgrund der durch die Legierungsbestandteile in einem bestimmten Bereich erzielte angehobene Festigkeit höhere Eigenspannungen entstehen können, welche durch das erfindungsgemäße Wärmenachbehandlungsverfahren beseitigt werden können.Before annealing, the parts should be pre-processed, namely roughed. The cast skin of the friction surface and the inside of the pot should be removed approx. 1.5 mm. The subsequent post-treatment method according to the invention eliminates both internal stresses generated during the cooling process and stresses caused by the machining. It is also essential that, due to the increased strength achieved by the alloy components in a certain area, higher residual stresses can arise, which can be eliminated by the heat treatment process according to the invention.
Auf diese Weise sind nach der Wärmebehandlung nur noch geringe Bearbeitungen notwendig, wodurch ein erneutes Auftreten von Spannungen vermieden werden kann.In this way, only minor machining operations are necessary after the heat treatment, as a result of which a renewed occurrence of stresses can be avoided.
Es wurde festgestellt, daß durch die angegebene längere Aufheizzeit für die Erwärmung der zu behandelnden Teile deren Verziehen vermieden wird. Die Abkühlung nach der angegebenen Haltezeit soll auf jeden Fall langsam vorgenommen werden, damit keine neuen Spannungen entstehen. Dies kann z.B. auf einfache Weise durch ein Abschalten des Glühofens erreicht werden, wobei die Teile noch längere Zeit in dem sich langsam abkühlenden Glühofen verbleiben.It was found that the longer heating time specified for the heating of the parts to be treated prevents their warping. The cooling down after the specified holding time should in any case be carried out slowly so that no new tensions arise. This can e.g. can be achieved in a simple manner by switching off the annealing furnace, the parts remaining in the slowly cooling annealing furnace for a relatively long time.
Claims (2)
über 3,6% Kohlenstoff
0,6 - 0,9% Mangan
1,8 - 2,5% Silizium
weniger als 0,1% Phosphor
weniger als 0,12 % Schwefel
und mit geringen Bestandteilen von Chrom, Molybdän und Kupfer,
wobei das Gußeisen ein perlitisches Grundgefüge aufweist,
gekennzeichnet durch
die Kombination folgender Merkmale:
einem perlitischen Grundgefüge mit maximal 5% Ferritanteil und einer Zugfestigkeit von mind. 200 N/mm² mit folgender chemischer Zusammensetzung:
Kohlenstoff 3,62 - 3,68 %
Silizium max. 2,10 %
Mangan 0,70 - 0,85 %
Phosphor weniger als 0,080 %
Schwefel weniger als 0,095 %
Chrom 0,18 - 0,25 %
Molybdän 0,30 - 0,45 %
Kupfer 0,30 - 0,45 %1) Cast iron for the production of brake drums, in particular of massive and ventilated brake discs and other brake bodies with an alloy of
over 3.6% carbon
0.6-0.9% manganese
1.8 - 2.5% silicon
less than 0.1% phosphorus
less than 0.12% sulfur
and with minor components of chrome, molybdenum and copper,
the cast iron has a pearlitic structure,
marked by
the combination of the following features:
a pearlitic basic structure with a maximum of 5% ferrite and a tensile strength of at least 200 N / mm² with the following chemical composition:
Carbon 3.62 - 3.68%
Silicon max. 2.10%
Manganese 0.70 - 0.85%
Phosphorus less than 0.080%
Sulfur less than 0.095%
Chromium 0.18 - 0.25%
Molybdenum 0.30 - 0.45%
Copper 0.30 - 0.45%
dadurch gekennzeichnet, daß
die zu behandelnden Teile in einer Anfahrzeit von 180 Minuten auf eine Temperatur von 650 - 720 Grad C gebracht und anschließend für 30 Minuten bei dieser Temperatur gehalten werden, wonach eine langsame Abkühlung im Glühofen auf 250 Grad C erfolgt.2) Method for post-heat treatment of the cast iron according to claim 1,
characterized in that
the parts to be treated are brought to a temperature of 650 - 720 degrees C in a start-up time of 180 minutes and then held at this temperature for 30 minutes, after which they are slowly cooled to 250 degrees C in the annealing furnace.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19873704679 DE3704679A1 (en) | 1987-02-14 | 1987-02-14 | CAST IRON FOR THE PRODUCTION OF BRAKE DRUM |
| DE3704679 | 1987-02-14 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| EP0279300A2 true EP0279300A2 (en) | 1988-08-24 |
| EP0279300A3 EP0279300A3 (en) | 1988-09-14 |
| EP0279300B1 EP0279300B1 (en) | 1991-05-15 |
Family
ID=6320990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP88101722A Expired - Lifetime EP0279300B1 (en) | 1987-02-14 | 1988-02-06 | Cast iron for the manufacture of brake drums |
Country Status (5)
| Country | Link |
|---|---|
| US (2) | US4948437A (en) |
| EP (1) | EP0279300B1 (en) |
| KR (1) | KR960005599B1 (en) |
| DE (2) | DE3704679A1 (en) |
| ES (1) | ES2022479B3 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0746635A4 (en) * | 1992-09-25 | 1995-07-19 | Detroit Diesel Corp | Alloyed grey iron having high thermal fatigue resistance and good machinability |
| EP0778355A1 (en) * | 1995-12-07 | 1997-06-11 | Mercedes-Benz Ag | Optimized composition of lamellar graphite gray cast iron for brake disks of utility vehicles |
| WO2007115772A1 (en) * | 2006-04-04 | 2007-10-18 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Brake disc of a disc brake |
| DE102004028902B4 (en) * | 2004-06-15 | 2017-11-09 | Robert Bosch Gmbh | brake disc |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2079060A1 (en) * | 1991-10-16 | 1993-04-17 | K-H Corporation | Prestressed brake drum or rotor |
| US5352305A (en) * | 1991-10-16 | 1994-10-04 | Dayton Walther Corporation | Prestressed brake drum or rotor |
| SE504536C2 (en) * | 1994-09-09 | 1997-03-03 | Volvo Ab | Perlitic gray iron and brake components made of gray iron |
| DE19525863A1 (en) * | 1995-07-15 | 1997-01-16 | Ae Goetze Gmbh | Mechanical seal for the tracks of caterpillars |
| DE19747111A1 (en) | 1997-10-24 | 1999-05-12 | Knorr Bremse Systeme | Brake disc for disc brakes |
| DE19929390B4 (en) | 1999-06-28 | 2004-05-06 | Otto Sauer Achsenfabrik Keilberg | Brake disc arrangement |
| US7163594B1 (en) * | 2003-10-10 | 2007-01-16 | Gunite Corporation | High tensile strength gray iron alloy |
| US7083685B1 (en) | 2005-07-15 | 2006-08-01 | Hino Motors, Ltd. | Gray cast iron member |
| ITBS20100196A1 (en) * | 2010-12-02 | 2012-06-03 | Freni Brembo Spa | CAST IRON, IN PARTICULAR FOR DISC BRAKE COMPONENTS |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2214652A (en) * | 1940-06-28 | 1940-09-10 | Perfect Circle Co | Iron alloy |
| DE716104C (en) * | 1939-03-14 | 1942-01-13 | Goetzewerke | Sealing ring subject to wear and tear, preferably a piston ring |
| SU329237A1 (en) * | 1970-07-28 | 1972-02-09 | ||
| DE3305184A1 (en) * | 1983-02-15 | 1984-08-23 | Buderus Ag, 6330 Wetzlar | Cast iron for the production of brake members |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53137814A (en) * | 1977-05-09 | 1978-12-01 | Hitachi Metals Ltd | Method of producing pearlite spheroidal graphite cast iron |
| JPS6024703A (en) * | 1983-07-20 | 1985-02-07 | Mitsubishi Electric Corp | Monopulse antenna |
| JPS60247036A (en) * | 1984-05-22 | 1985-12-06 | Mitsui Eng & Shipbuild Co Ltd | Cv-cast iron cylinder liner |
-
1987
- 1987-02-14 DE DE19873704679 patent/DE3704679A1/en active Granted
-
1988
- 1988-02-06 EP EP88101722A patent/EP0279300B1/en not_active Expired - Lifetime
- 1988-02-06 DE DE8888101722T patent/DE3862767D1/en not_active Expired - Lifetime
- 1988-02-06 ES ES88101722T patent/ES2022479B3/en not_active Expired - Lifetime
- 1988-02-11 US US07/155,040 patent/US4948437A/en not_active Expired - Lifetime
- 1988-02-13 KR KR1019880001423A patent/KR960005599B1/en not_active IP Right Cessation
-
1990
- 1990-05-25 US US07/529,141 patent/US5032194A/en not_active Expired - Lifetime
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE716104C (en) * | 1939-03-14 | 1942-01-13 | Goetzewerke | Sealing ring subject to wear and tear, preferably a piston ring |
| US2214652A (en) * | 1940-06-28 | 1940-09-10 | Perfect Circle Co | Iron alloy |
| SU329237A1 (en) * | 1970-07-28 | 1972-02-09 | ||
| DE3305184A1 (en) * | 1983-02-15 | 1984-08-23 | Buderus Ag, 6330 Wetzlar | Cast iron for the production of brake members |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0746635A4 (en) * | 1992-09-25 | 1995-07-19 | Detroit Diesel Corp | Alloyed grey iron having high thermal fatigue resistance and good machinability |
| EP0746635A1 (en) * | 1992-09-25 | 1996-12-11 | Detroit Diesel Corporation | Alloyed grey iron having high thermal fatigue resistance and good machinability |
| EP0778355A1 (en) * | 1995-12-07 | 1997-06-11 | Mercedes-Benz Ag | Optimized composition of lamellar graphite gray cast iron for brake disks of utility vehicles |
| US5894010A (en) * | 1995-12-07 | 1999-04-13 | Mercedes-Benz Ag | Optimized gray cast iron plate alloy for utility vehicle brake disks |
| DE102004028902B4 (en) * | 2004-06-15 | 2017-11-09 | Robert Bosch Gmbh | brake disc |
| WO2007115772A1 (en) * | 2006-04-04 | 2007-10-18 | Knorr-Bremse Systeme für Nutzfahrzeuge GmbH | Brake disc of a disc brake |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3862767D1 (en) | 1991-06-20 |
| DE3704679A1 (en) | 1988-08-25 |
| KR880010138A (en) | 1988-10-07 |
| EP0279300B1 (en) | 1991-05-15 |
| US4948437A (en) | 1990-08-14 |
| EP0279300A3 (en) | 1988-09-14 |
| DE3704679C2 (en) | 1989-11-23 |
| KR960005599B1 (en) | 1996-04-26 |
| US5032194A (en) | 1991-07-16 |
| ES2022479B3 (en) | 1991-12-01 |
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