EP0173913A1 - Process for treating cast iron with silicon carbide - Google Patents
Process for treating cast iron with silicon carbide Download PDFInfo
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- EP0173913A1 EP0173913A1 EP85110449A EP85110449A EP0173913A1 EP 0173913 A1 EP0173913 A1 EP 0173913A1 EP 85110449 A EP85110449 A EP 85110449A EP 85110449 A EP85110449 A EP 85110449A EP 0173913 A1 EP0173913 A1 EP 0173913A1
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- silicon carbide
- cast iron
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- oxidizing
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C1/00—Refining of pig-iron; Cast iron
- C21C1/08—Manufacture of cast-iron
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
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- silicon carbide for the treatment of cast iron melts, such as for siliciding, carburizing, deoxidizing and seeding, has long been state of the art (cf. US-A-2020171, DE-C-2215266 and DE-A-2746478).
- metallurgical silicon carbide is usually used, the SiC content of which varies in the range of approximately 85-95% by weight and which, from the production point of view, still contains approximately 2-5% by weight of free carbon and approximately 2-3% by weight.
- Has silicon dioxide which is available in the form of grain sizes in the range up to 20 mm with a maximum grain size distribution of ⁇ 10 mm.
- This object is achieved in that an SiC is used which has been subjected to an oxidizing treatment before being introduced into the cast iron melt in such a way that the individual silicon carbide grains are partially surrounded by a silicon dioxide-containing shell.
- the individual SiC grains are not completely surrounded by a layer containing uniformly thick silicon dioxide, but that this layer is interrupted at individual points on the grain surface, ie either completely missing at these points or only very little is thin.
- This can be achieved, for example, by exposing a granular silicon carbide in a stationary or moving bed to an oxidizing atmosphere, such as air, oxygen or water vapor, at temperatures in the range from 900 ° C. to 1,600 ° C.
- the individual grains are oxidized on the free surfaces to form the Si0 2 layer and agglomerated at the same time.
- the agglomerates are then subjected to gentle comminution in order to expose the silicon carbide surfaces which were completely or partially removed from the oxidative attack due to the formation of the agglomerates.
- a silicon carbide with grain sizes of 0.5 mm and finer, in particular in the range from 0.1 mm to 0.5 mm, and an SiC content of at least 95% by weight in a stationary bed is used of flowing air at temperatures of 1,250 ° C - 1,300 ° C subjected to the oxidizing treatment.
- layer thicknesses of the silicon dioxide-containing shell can be produced up to approximately 15 ⁇ m, in particular in the range from 0.5 ⁇ m to 5 ⁇ m.
- the degree of oxidation can be determined from the decrease in the original SiC content.
- the subsequent comminution under mild conditions can be carried out in a mortar, for example.
- the process according to the invention is not limited to this preferred embodiment, but it is within the scope of the invention that both the parameters for the oxidizing treatment and for the silicon carbide which is subjected to this treatment can be varied within a wide range.
- the silicon carbide pretreated according to the invention can be introduced into the cast iron melt in a customary known manner, such as by addition in the melting unit, in and before the holding unit or in the forehearth or by addition to the type before melting. Furthermore, it can be used both in the form of a loose granulation and in the form of pellets or briquettes which have been compacted in the customary known manner.
- This SiC was stored as a loose bed in an electrically heated tube furnace and oxidized for 72 hours at 1,250 ° C - 1,300 ° C under a slight negative pressure (0.4 - 0.6 bar) in a flowing air atmosphere. After cooling, the agglomerated product was removed from the oven and crushed in a mortar by gentle breaking.
- the SiC content was 93.9% by weight and the Si0 2 content was 4.6% by weight.
- the degree of oxidation ie the percentage of oxidized SiC, calculated from the decrease in the SiC content and corresponding to the increase in the Si0 2 content, was thus 3%.
- the layer thickness of the Si0 2 coating was a maximum of 5 microns.
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- Engineering & Computer Science (AREA)
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- Metallurgy (AREA)
- Organic Chemistry (AREA)
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- Carbon And Carbon Compounds (AREA)
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
Description
Die Verwendung von Siliciumcarbid zur Behandlung von Gußeisenschmelzen, wie zum Aufsilizieren, Aufkohlen, Desoxidieren und Impfen ist seit langem Stand der Technik (vgl. US-A-2020171, DE-C-2215266 und DE-A-2746478).The use of silicon carbide for the treatment of cast iron melts, such as for siliciding, carburizing, deoxidizing and seeding, has long been state of the art (cf. US-A-2020171, DE-C-2215266 and DE-A-2746478).
Hierfür wird üblicherweise sogenanntes metallurgisches Siliciumcarbid eingesetzt, dessen SiC-Gehalt im Bereich von etwa 85 - 95 Gew.-% variiert und das von der Herstellung her noch etwa 2 - 5 Gew.-% freien Kohlenstoff und etwa 2 - 3 Gew.-% Siliciumdioxid aufweist, das in Form von Körnungen im Bereich bis zu 20 mm mit einem Maximum der Kornverteilung von <10 mm im Handel verfügbar ist.For this purpose, so-called metallurgical silicon carbide is usually used, the SiC content of which varies in the range of approximately 85-95% by weight and which, from the production point of view, still contains approximately 2-5% by weight of free carbon and approximately 2-3% by weight. Has silicon dioxide, which is available in the form of grain sizes in the range up to 20 mm with a maximum grain size distribution of <10 mm.
Die Verwendung von metallurgischem Siliciumcarbid als Legierungsmittel hat einen positiven Einfluß auf die Qualität des Gußeisens, da während des Aufsilizierens eine Vorimpfung der Schmelze eintritt und dieser Vorimpfeffekt nur langsam abklingt. Er äußert sich in einer geringen Unterkühlung der Schmelze, einer Erhöhung der Zahl eutektischer Körner, einer günstigen Verteilung und Ausbildung des Graphits und einer verminderten Neigung zur Weiß- bzw. verstärkten Neigung zur Grauerstarrung. Die Folge ist eine Verbesserung der Festigkeitseigenschaften, der ralativen Härte und der gleichmäßigen Güte der Gußwerkstoffe (vgl. Untersuchungen von K. H. Caspers in "Gießerei", Bd. 59 (1972), S. 556-559 und zusammenfassende Darstellung von Th. Benecke in "Gießerei", Bd. 68 Uber die Ursachen der Impfwirkung des metallurgischen Siliciumcarbids und deren Langzeiteffekt ist praktisch nichts bekannt. Aus vergleichenden Untersuchungen von R. L. Doelmann und Mitarbeitern in "Gießerei-Praxis", Nr. 12 (1981), S. 205-212 scheint zwar hervorzugehen, daß mit 80 %igem Siliciumcarbid ein Gußeisen mit besseren Eigenschaften erzeugt werden kann als mit 90 %igem Siliciumcarbid, was die Autoren mit dem höheren Kohlenstoffgehalt (7,2 %) in Form von Graphit und thermisch behandeltem Petrolkoks in dem 80 %igen Siliciumcarbid in Verbindung zu bringen versuchen.The use of metallurgical silicon carbide as an alloying agent has a positive influence on the quality of the cast iron, since pre-inoculation of the melt occurs during the siliconization and this pre-inoculation effect subsides only slowly. It manifests itself in a slight hypothermia in the melt, an increase in the number of eutectic grains, a favorable distribution and formation of the graphite and a reduced tendency towards white or increased tendency towards gray solidification. The result is an improvement in the strength properties, the relative hardness and the uniform quality of the casting materials (cf. investigations by KH Caspers in "Gießerei", Vol. 59 (1972), pp. 556-559 and summary by Th. Benecke in " Foundry ", Vol. 68 Practically nothing is known about the causes of the inoculation effect of the metallurgical silicon carbide and its long-term effect. From comparative studies by R. L. Doelmann and employees in "foundry practice," N o. 12 (1981), pp. 205-212 seems to show that a cast iron with better properties can be produced with 80% silicon carbide than with 90% silicon carbide, which the authors with the higher carbon content (7.2%) in form try to combine graphite and thermally treated petroleum coke in the 80% silicon carbide.
Das ermöglicht jedoch nicht die gezielte Auswahl bestimmter metallurgischer SiC-Sorten, die reproduzierbar zu jeweils gleichen Ergebnissen unter jeweils gleichen Schmelzbedingungen führen, da die einzelnen Faktoren, die bei Einsatz von SiC für die Keimbildung in der Schmelze verantwortlich sind, nach wie vor unbekannt sind.However, this does not make it possible to select specific metallurgical SiC grades that reproducibly lead to the same results under the same melting conditions, since the individual factors that are responsible for nucleation in the melt when using SiC are still unknown.
Es stellt sich somit die Aufgabe der Auswahl eines Siliciumcarbids für die Behandlung von Gußeisenschmelzen, das so beschaffen sein muß, daß es die Keimbildung in der Gußeisenschmelze gezielt zu steuern vermag, ohne daß hierzu eine aufwendige Vorsortierung handelsüblicher metallurgischer SiC-Qualitäten erforderlich ist, die von der Herstellung her jeweils unterschiedliche Mengen an Begleitstoffen enthalten.It is therefore the task of selecting a silicon carbide for the treatment of cast iron melts, which must be such that it can control the nucleation in the cast iron melt in a targeted manner, without the need for complex pre-sorting of commercially available metallurgical SiC qualities, which is required by contain different amounts of accompanying substances during manufacture.
Diese Aufgabe wird erfindungsgemäß dadurch gelöst, daß ein SiC verwendet wird, das vor dem Einbringen in die Gußeisenschmelze einer oxidierenden Behandlung unterzogen worden ist, derart, daß die einzelnen Siliciumcarbidkörner teilweise mit einer Siliciumdioxid enthaltenden Hülle umgeben sind.This object is achieved in that an SiC is used which has been subjected to an oxidizing treatment before being introduced into the cast iron melt in such a way that the individual silicon carbide grains are partially surrounded by a silicon dioxide-containing shell.
Für das erfindungsgemäß zu verwendende Siliciumcarbid ist es entscheidend, daß die einzelnen SiC-Körner nicht vollständig mit einer gleichmäßig dicken Siliciumdioxid enthaltenden Schicht umgeben sind, sondern daß diese Schicht an einzelnen Stellen der Kornoberfläche unterbrochen ist, d.h. an diesen Stellen entweder vollständig fehlt oder nur sehr dünn ist. Das kann beispielsweise dadurch erreicht werden, daß ein Siliciumcarbid in körniger Form in ruhender oder bewegter Schüttung einer oxidierenden Atmosphäre, wie Luft, Sauerstoff oder Wasserdampf, bei Temperaturen im Bereich von 900 °C - 1.600 °C ausgesetzt wird. Dabei werden die einzelnen Körner an den freien Oberflächen unter Bildung der Si02-schicht oxidiert und gleichzeitig agglomeriert. Die Agglomerate werden anschließend einer schonenden Zerkleinerung unterzogen zur Freilegung der Siliciumcarbidoberflächen, die durch die Agglomeratbildung dem oxidativen Angriff ganz oder teilweise entzogen waren.For the silicon carbide to be used according to the invention, it is crucial that the individual SiC grains are not completely surrounded by a layer containing uniformly thick silicon dioxide, but that this layer is interrupted at individual points on the grain surface, ie either completely missing at these points or only very little is thin. This can be achieved, for example, by exposing a granular silicon carbide in a stationary or moving bed to an oxidizing atmosphere, such as air, oxygen or water vapor, at temperatures in the range from 900 ° C. to 1,600 ° C. The individual grains are oxidized on the free surfaces to form the Si0 2 layer and agglomerated at the same time. The agglomerates are then subjected to gentle comminution in order to expose the silicon carbide surfaces which were completely or partially removed from the oxidative attack due to the formation of the agglomerates.
Nach einer bevorzugten Ausführungsform der Erfindung wird ein Siliciumcarbid mit Korngrößen von 0,5 mm und feiner, insbesondere im Bereich von 0,1 mm bis 0,5 mm, und einem SiC-Gehalt von mindestens 95 Gew.-% in ruhender Schüttung unter Verwendung von stömender Luft bei Temperaturen von 1.250 °C - 1.300 °C der oxidierenden Behandlung unterzogen. Unter diesen Bedingungen können in Abhängigkeit von der Zeit Schichtdicken der Siliciumdioxid enthaltenden Hülle bis etwa 15 µm, insbesondere im Bereich 0,5 um bis 5 um, erzeugt werden. Der Oxidationsgrad kann dabei aus der Abnahme des ursprünglichen SiC-Gehaltes ermittelt werden. Die anschließende Zerkleinerung unter schonenden Bedingungen kann beispielsweise in einem Mörser vorgenommen werden. Unter schonenden Bedingungen ist hierbei zu verstehen, daß nur die agglomerierten Körner getrennt, nicht aber die Körner selbst weiter zerkleinert werden, so daß die ursprünglich eingesetzten Korngrößen praktisch unverändert bleiben. Durch diese gezielte Vorbehandlung wird ein Siliciumcarbid von genau definierter Beschaffenheit erhalten, dessen Impfwirkung mit Langzeiteffekt in Guß- eisenschmelzen mit unterschiedlichem Sättigungsgrad nachgewiesen wurde, wie in den folgenden Beispielen näher erläutert. Als Gußeisenschmelzen wurden dabei solche von hoher Reinheit verwendet, die naturgemäß besonders keimarm sind.According to a preferred embodiment of the invention, a silicon carbide with grain sizes of 0.5 mm and finer, in particular in the range from 0.1 mm to 0.5 mm, and an SiC content of at least 95% by weight in a stationary bed is used of flowing air at temperatures of 1,250 ° C - 1,300 ° C subjected to the oxidizing treatment. Under these conditions, depending on the time, layer thicknesses of the silicon dioxide-containing shell can be produced up to approximately 15 μm, in particular in the range from 0.5 μm to 5 μm. The degree of oxidation can be determined from the decrease in the original SiC content. The subsequent comminution under mild conditions can be carried out in a mortar, for example. Gentle conditions mean that only the agglomerated grains are separated, but not the grains themselves are further crushed, so that the grain sizes originally used remain practically unchanged. This targeted pretreatment turns a silicon carbide into a precisely defined material was obtained, the vaccination effect iron melt with long-term effect in G USS detected with different degree of saturation, as explained in more detail in the following examples. Cast iron melts of high purity were used, which are naturally particularly low in germs.
Das erfindungsgemäße Verfahren ist jedoch nicht auf diese bevorzugte Ausführungsform beschränkt, sondern es liegt im Rahmen der Erfindung, daß sowohl die Parameter für die oxidierende Behandlung, als auch für das Siliciumcarbid, das dieser Behandlung unterzogen wird, in breitem Rahmen variiert werden können.However, the process according to the invention is not limited to this preferred embodiment, but it is within the scope of the invention that both the parameters for the oxidizing treatment and for the silicon carbide which is subjected to this treatment can be varied within a wide range.
Das Einbringen des erfindungsgemäß vorbehandelten Siliciumcarbids in die Gußeisenschmelze kann in üblicher bekannter Weise vorgenommen werden, wie durch Zugabe im Schmelzaggregat, im und vor dem Warmhalteaggregat oder im Vorherd oder durch Zugabe zu der Gattierung vor dem Aufschmelzen. Ferner kann es sowohl in Form einer losen Körnung als auch in Form von Pellets oder Briketts eingesetzt werden, die in üblicher bekannter Weise kompaktiert worden sind.The silicon carbide pretreated according to the invention can be introduced into the cast iron melt in a customary known manner, such as by addition in the melting unit, in and before the holding unit or in the forehearth or by addition to the type before melting. Furthermore, it can be used both in the form of a loose granulation and in the form of pellets or briquettes which have been compacted in the customary known manner.
Herstellung eines vorbehandelten Siliciumcarbids:
- Als Ausgangsmaterial wurde kristallines Siliciumcarbid mit einem SiC-Gehalt von 98,5 Gew.-%, einem Si02-Gehalt von 0,26 Gew.-% und einer Korngröße von 0,1 - 0,5 mm verwendet, das frisch aufgemahlen und abgesiebt worden war.
- Crystalline silicon carbide with an SiC content of 98.5% by weight, an SiO 2 content of 0.26% by weight and a grain size of 0.1-0.5 mm was used as the starting material, which was freshly ground and had been screened.
Dieses SiC wurde als lose Schüttung in einem elektrisch beheizten Rohrofen untergebracht und bei 1.250 °C - 1.300 °C unter leichtem Unterdruck (0,4 - 0,6 Bar)in strömender Luftatmosphäre 72 Stunden oxidiert. Nach dem Abkühlen wurde das agglomerierte Produkt aus dem Ofen entnommen und durch schonendes Brechen in einem Mörser zerkleinert.This SiC was stored as a loose bed in an electrically heated tube furnace and oxidized for 72 hours at 1,250 ° C - 1,300 ° C under a slight negative pressure (0.4 - 0.6 bar) in a flowing air atmosphere. After cooling, the agglomerated product was removed from the oven and crushed in a mortar by gentle breaking.
Nach der Oxidation betrug der SiC-Gehalt 93,9 Gew.-% und der Si02-Gehalt 4,6 Gew.-%. Der Oxidationsgrad, d.h. der Prozentsatz an oxidiertem SiC, errechnet aus der Abnahme des SiC-Gehalts und entsprechend der Zunahme des Si02-Gehaltes, betrug somit 3 %. Die Schichtdicke der Si02-Umhüllung betrug maximal 5 µm.After the oxidation, the SiC content was 93.9% by weight and the Si0 2 content was 4.6% by weight. The degree of oxidation, ie the percentage of oxidized SiC, calculated from the decrease in the SiC content and corresponding to the increase in the Si0 2 content, was thus 3%. The layer thickness of the Si0 2 coating was a maximum of 5 microns.
Die Erzeugung der teilweisen SiO2-Umhüllung der SiC-Körner ist in Figur 1a - c schematisch dargestellt.
- Figur 1a zeigt die SiC-Körner vor der Oxidation: 1 sind die Berührungsstellen der Körner;
- Figur 1b zeigt die SiC-Körner nach der Oxidation: 2 ist die erzeugte SiO2-Schicht;
- Figur 1c zeigt die SiC-Körner nach dem schonenden Brechen: 2 ist die erzeugte SiO2-Schicht, die durch freigelegte Oberflächen an den
Stellen 3 unterbrochen ist.
- Figure 1a shows the SiC grains before oxidation: 1 are the contact points of the grains;
- FIG. 1b shows the SiC grains after the oxidation: 2 is the SiO 2 layer produced;
- Figure 1c shows the SiC grains after gentle breaking: 2 is the SiO 2 layer produced, which is interrupted by exposed surfaces at
points 3.
Einsatz des nach Beispiel 1 vorbehandelten Siliciumcarbids zum Vorimpfen von Gußeisenschmelzen im Vergleich zu unbehandeltem SiC:
- Die Schmelze enthielt jeweils 2 Gew.-% Si.
- The melt contained 2% by weight of Si.
Zugabe des Si-Trägers entweder im Kalteinsatz oder durch Einrühren bei 1.350 °C.Add the Si carrier either in cold use or by stirring in at 1,350 ° C.
Sofern nicht anders angegeben, Sättigungsgrad (Sc) der Schmelze = 0,91 %, = C-Gehalt der Schmelze 3,3 Gew.-%.Unless stated otherwise, degree of saturation (Sc) of the melt = 0.91%, = C content of the melt 3.3% by weight.
S-Gehalt der Schmelze = 0,035 Gew.-%.S content of the melt = 0.035% by weight.
Korngröße des SiC: unbehandelt 0 - 1 mm vorbehandelt 0,1 - 0,5 mm.Grain size of the SiC: untreated 0 - 1 mm pretreated 0.1 - 0.5 mm.
Einsatz im kalten Tiegel: Reinsteisen (99,9 Gew.-% Fe), Graphit (99,99 Gew.-% C), Eisensulfid (> 99 Gew.-% FeS).Use in cold crucibles: pure iron (99.9% by weight Fe), graphite (99.99% by weight C), iron sulfide (> 99% by weight FeS).
Aufheizen, Schmelzen, Halten in einem elektrisch beheizten Tiegelofen unter CO-Gasschleier:
- 1. Aufheizen mit 70 - 80 °C/min bis
- 2. 1.350 °C: 2 min Rühren bzw. Einrühren der Si-Träger und je nach Beispiel Halten oder
- 3. Weiteraufheizen mit 50 - 60 °C/min bis 1.500 °C: Halten;
- 4. Abkühlen der Schmelze im Tiegel mit 25 - 30 °C/min.
- 1. Heating at 70 - 80 ° C / min to
- 2. 1,350 ° C: 2 min stirring or stirring in the Si carrier and, depending on the example, hold or
- 3. Continue heating at 50 - 60 ° C / min to 1,500 ° C: hold;
- 4. Cool the melt in the crucible at 25-30 ° C / min.
Die Ergebnisse sind in den Tabellen 1 - 3 zusammengestellt. Wie hieraus ersichtlich, ist der verbesserte Vorimpfeffekt des erfindungsgemäß vorbehandelten SiC im Vergleich zu unbehandeltem SiC deutlich nachweisbar. Er äußert sich in einer geringeren eutektischen Unterkühlung, Vergrößerung der Zahl der eutektischen Körner, Verbesserung der Graphitausscheidung in Form von A-Graphit und insbesondere in einer beträchtlichen Verbesserung der Neigung zur Grauerstarrung.The results are summarized in Tables 1-3. As can be seen from this, the improved pre-vaccination effect of the SiC pretreated according to the invention compared to untreated SiC can be clearly demonstrated. It expresses itself in one less eutectic hypothermia, increase in the number of eutectic grains, improvement of graphite excretion in the form of A-graphite and in particular in a considerable improvement in the tendency to gray solidification.
Zum weiteren Vergleich wurde ein handelsübliches FeSi 75 Ca herangezogen.
Claims (3)
dadurch gekennzeichnet,
daß ein Siliciumcarbid verwendet wird, das vor dem Einbringen in die Gußeisenschmelze einer oxidierenden Behandlung unterzogen worden ist, derart, daß die einzelnen Siliciumcarbidkörner teilweise mit einer Siliciumdioxid enthaltenden Hülle umgeben sind.1. Process for treating cast iron melts with silicon carbide,
characterized,
that a silicon carbide is used which has been subjected to an oxidizing treatment before being introduced into the cast iron melt, in such a way that the individual silicon carbide grains are partially surrounded by a casing containing silicon dioxide.
dadurch gekennzeichnet,
daß ein Siliciumcarbid in körniger Form in ruhender oder bewegter Schüttung einer oxidierenden Atmosphäre bei Temperaturen im Bereich von 900 °C bis 1.600 °C ausgesetzt wird, die gebildeten Agglomerate anschließend einer schonenden Zerkleinerung unterzogen werden zur Freilegung der Siliciumcarbidoberflächen, die durch die Agglomeratbildung dem oxidativen Angriff ganz oder teilweise entzogen waren und das so vorbehandelte Siliciumcarbid in die Gußeisenschmelze eingebracht wird.2. The method according to claim 1,
characterized,
that a granular form of silicon carbide in static or moving bed is exposed to an oxidizing atmosphere at temperatures in the range from 900 ° C to 1,600 ° C, the agglomerates formed are then subjected to gentle comminution to expose the silicon carbide surfaces which are exposed to oxidative attack due to the formation of agglomerates were wholly or partially withdrawn and the silicon carbide pretreated in this way is introduced into the cast iron melt.
dadurch gekennzeichnet ,
daß ein Siliciumcarbid mit Korngrößen von 0,5 mm und feiner und einem SiC-Gehalt von mindestens 95 Gew.-% in ruhender Schüttung einer strömenden Luftatmosphäre bei Temperaturen von 1.250 °C bis 1.300 °C bis zur Bildung einer Schichtdicke der Siliciumdioxid enthaltenden Hülle von bis zu 15 µm ausgesetzt wird, die agglomerierten Körner anschließend unter schonenden Bedingungen getrennt und dann in die Gußeisenschmelze eingebracht werden.3. The method according to claim 1 and 2,
characterized ,
that a silicon carbide with grain sizes of 0.5 mm and finer and an SiC content of at least 95 wt .-% in still bed of a flowing air atmosphere at temperatures from 1,250 ° C to 1,300 ° C until the formation of a layer thickness of the silicon dioxide-containing shell exposed to up to 15 µm, the agglomerated grains are then separated under gentle conditions and then introduced into the cast iron melt.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AT85110449T ATE41176T1 (en) | 1984-08-24 | 1985-08-20 | METHOD OF TREATMENT OF CAST IRON MELT WITH SILICON CARBIDE. |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE3431263 | 1984-08-24 | ||
| DE19843431263 DE3431263A1 (en) | 1984-08-24 | 1984-08-24 | METHOD FOR TREATING CAST IRON MELT WITH SILICON CARBIDE |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0173913A1 true EP0173913A1 (en) | 1986-03-12 |
| EP0173913B1 EP0173913B1 (en) | 1989-03-08 |
Family
ID=6243848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP85110449A Expired EP0173913B1 (en) | 1984-08-24 | 1985-08-20 | Process for treating cast iron with silicon carbide |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4642135A (en) |
| EP (1) | EP0173913B1 (en) |
| JP (1) | JPS6164809A (en) |
| AT (1) | ATE41176T1 (en) |
| DE (2) | DE3431263A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0324832A1 (en) * | 1987-07-09 | 1989-07-26 | Alcan International Limited | Preparation of composite materials |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH03503399A (en) * | 1988-03-11 | 1991-08-01 | ディーア・アンド・カンパニー | Manufacture of SiC, MnC and ferroalloys |
| US20040103755A1 (en) * | 2002-08-12 | 2004-06-03 | Beyerstedt Ronald Jay | Method of producing cast iron |
| FR3003577B1 (en) * | 2013-03-19 | 2016-05-06 | Ferropem | INOCULANT WITH SURFACE PARTICLES |
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| US2527829A (en) * | 1948-11-12 | 1950-10-31 | Electro Refractories & Alloys | Foundry additives |
| GB937104A (en) * | 1959-04-17 | 1963-09-18 | Ct Technique Des Ind Fonderie | Method of making additions to molten metal |
| DE2034806A1 (en) * | 1969-09-02 | 1971-04-08 | Meehanite Metal Corp , White Plains, NY (VStA) | Process for melting cast iron |
| DE2215266C3 (en) * | 1972-03-29 | 1978-04-20 | Elektroschmelzwerk Kempten Gmbh, 8000 Muenchen | Process for accelerating the rate of dissolution of silicon carbide in iron melts |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2569146A (en) * | 1949-11-30 | 1951-09-25 | American Metaliurgical Product | Metallurgical addition agent |
| US2771356A (en) * | 1953-09-25 | 1956-11-20 | United States Steel Corp | Method of deoxidizing semi-killed steel |
| US3051564A (en) * | 1959-08-12 | 1962-08-28 | Carborundum Co | Composition for metallurgical use and process of using the same |
| US3158465A (en) * | 1961-09-07 | 1964-11-24 | Kerchner Marshall & Company | Metallurgical material and process for treating iron therewith |
-
1984
- 1984-08-24 DE DE19843431263 patent/DE3431263A1/en not_active Withdrawn
-
1985
- 1985-08-16 US US06/766,635 patent/US4642135A/en not_active Expired - Fee Related
- 1985-08-20 AT AT85110449T patent/ATE41176T1/en active
- 1985-08-20 EP EP85110449A patent/EP0173913B1/en not_active Expired
- 1985-08-20 DE DE8585110449T patent/DE3568592D1/en not_active Expired
- 1985-08-23 JP JP60184341A patent/JPS6164809A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2527829A (en) * | 1948-11-12 | 1950-10-31 | Electro Refractories & Alloys | Foundry additives |
| GB937104A (en) * | 1959-04-17 | 1963-09-18 | Ct Technique Des Ind Fonderie | Method of making additions to molten metal |
| DE2034806A1 (en) * | 1969-09-02 | 1971-04-08 | Meehanite Metal Corp , White Plains, NY (VStA) | Process for melting cast iron |
| DE2215266C3 (en) * | 1972-03-29 | 1978-04-20 | Elektroschmelzwerk Kempten Gmbh, 8000 Muenchen | Process for accelerating the rate of dissolution of silicon carbide in iron melts |
Non-Patent Citations (1)
| Title |
|---|
| GIESSEREI, Band 68, Nr. 12, 8. Juni 1981, Seiten 344-347, Düsseldorf, DE; Th. BENECKE: "Metallurgisches Siliciumcarbid im Elektro- und Kupolofen" * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0324832A1 (en) * | 1987-07-09 | 1989-07-26 | Alcan International Limited | Preparation of composite materials |
| EP0324832A4 (en) * | 1987-07-09 | 1989-11-23 | Dural Aluminum Composites Corp | Preparation of composite materials. |
Also Published As
| Publication number | Publication date |
|---|---|
| US4642135A (en) | 1987-02-10 |
| DE3568592D1 (en) | 1989-04-13 |
| JPS6310203B2 (en) | 1988-03-04 |
| JPS6164809A (en) | 1986-04-03 |
| ATE41176T1 (en) | 1989-03-15 |
| EP0173913B1 (en) | 1989-03-08 |
| DE3431263A1 (en) | 1986-03-06 |
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