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EP0565763A1 - Agent and process for calcium treating of steel - Google Patents

Agent and process for calcium treating of steel Download PDF

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Publication number
EP0565763A1
EP0565763A1 EP92106619A EP92106619A EP0565763A1 EP 0565763 A1 EP0565763 A1 EP 0565763A1 EP 92106619 A EP92106619 A EP 92106619A EP 92106619 A EP92106619 A EP 92106619A EP 0565763 A1 EP0565763 A1 EP 0565763A1
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EP
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Prior art keywords
calcium
steel
calcium carbide
weight
agent
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.)
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Application number
EP92106619A
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German (de)
French (fr)
Other versions
EP0565763B1 (en
Inventor
Bernd Dr. Neuer
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Evonik Operations GmbH
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SKW Trostberg AG
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Priority to DE59207996T priority Critical patent/DE59207996D1/en
Priority to AT92106619T priority patent/ATE148504T1/en
Publication of EP0565763A1 publication Critical patent/EP0565763A1/en
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Classifications

    • 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
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/04—Removing impurities by adding a treating agent
    • C21C7/06—Deoxidising, e.g. killing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
    • 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
    • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
    • C21C7/0056—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00 using cored wires

Definitions

  • the present invention relates to means and methods for calcium treatment of liquid steel, in particular for the targeted modification of non-metallic inclusions in steel.
  • an agent for calcium treatment of steel in the form of a cored wire on a metallic sheath and a fine-grained filler material based on calcium carbide which is characterized in that the filler material additionally contains a gas-releasing or gas-developing substance at the temperature of the steel melt in an amount of 2 to 60 wt .-%, calculated on the weight of calcium carbide.
  • the filler material additionally contains a gas-releasing or gas-developing substance at the temperature of the steel melt in an amount of 2 to 60 wt .-%, calculated on the weight of calcium carbide.
  • the cored wire can have a diameter of 5 to 20 mm depending on the application and size of the pans available.
  • a cored wire with a diameter of 9 to 13 mm is preferably used.
  • a type of coal is preferably selected which, as a dried product, releases about 90% by weight of its volatile constituents at the temperature of the steel melt within less than 60 seconds, preferably less than 40 seconds.
  • the higher the volatile content of the coal the higher the effectiveness of the treatment agents.
  • Coals which contain at least 25% by weight of volatile constituents and which, after entering the molten steel, develop a gas volume of at least 150 NL / kg are particularly preferably used. Coals that meet these conditions are, in particular, brown coal, flame coal, gas flame coal, gas coal and fat coal.
  • the grain size of the coal is adjusted approximately to that of the calcium carbide.
  • the filler material preferably contains 85 to 98% by weight of calcium carbide and 15 to 2% by weight of a dried coal with a moisture content of ⁇ 0.5%.
  • the filling material contains 90 to 95% by weight calcium carbide and 10 to 5% by weight flame carbon.
  • Calcium carbide as calcium source is used in the form of technical calcium carbide with contents of 50 to 85 wt .-% CaC2.
  • High-percentage calcium carbide of 75 to 85% by weight CaC2 is preferably used, since this means that the calcium concentration is correspondingly high and the amount of slag introduced into the melt is reduced.
  • the grain size of the calcium carbide used should advantageously be ⁇ 1 mm, preferably ⁇ 0.5 mm.
  • calcium metal or calcium silicon have the advantage that they simultaneously provide calcium.
  • Commercial technical products are used here, the purity of the calcium metal being approximately 95%, the calcium silicon alloy normally containing 30% by weight calcium and 60% by weight silicon, and the rest consisting of iron and production-related impurities.
  • 5 to 60% by weight of the calcium carbide in the filling material can be replaced by calcium silicon, so that the proportion of calcium carbide is 40 to 95% by weight.
  • a composition of the filling material of 40 to 80% by weight of calcium carbide and 60 to 20% by weight of calcium silicon is preferred.
  • the grain sizes of the calcium carbide and the calcium or the calcium silicon alloy should be approximately in the same range and should be ⁇ 1 mm, preferably ⁇ 0.5 mm.
  • the treatment of the molten steel with the agent according to the invention can be carried out safely and easily with the aid of a commercially available winding device.
  • the desired calcium concentration in the steel which should generally be between 20 and 50 ppm, approximately 0.6 kg of filler material, corresponding to approximately 3.5 m of cored wire with a diameter of 13 mm per ton of steel melt to be treated, is used.
  • winding speeds 100 to 300 m / min., Preferably from 200 to 250 m / min., Are used.
  • the agent is introduced deep enough into the molten steel. The resulting turbulence ensures that the calcium component is used in the best possible way and that the molten steel is mixed and homogenized well.
  • Table 1 describe the treatment of 70 t batches of molten steel in a ladle, the temperature of the molten steel being approximately 1620 ° C.
  • the treated steel melts should contain 25 to 40 ppm calcium in order to be cast on a billet caster and to be used as a low-alloy stainless steel.
  • a cored wire with a diameter of 13 mm was used, which with a speed of 180 to 200 m / min. was wound into the molten steel.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Treatment Of Steel In Its Molten State (AREA)

Abstract

An agent for the calcium treatment of steel in the form of a filler wire has a metallic shell and a fine-grained filling material based on calcium carbide, whose filling material additionally contains a substance, which releases or evolves gas at the temperature of the molten steel, in a quantity of 2 to 60 % by weight, calculated on the weight of the calcium carbide.

Description

Die vorliegende Erfindung betrifft Mittel und Verfahren zur Calciumbehandlung von flüssigem Stahl insbesondere zur gezielten Modifikation nichtmetallischer Einschlüsse im Stahl.The present invention relates to means and methods for calcium treatment of liquid steel, in particular for the targeted modification of non-metallic inclusions in steel.

Zum Einbringen von Calcium in den flüssigen Stahl haben sich weltweit Injektionstechniken durchgesetzt. Beim sogenannten TN-Verfahren wird feinkörniges Calciumsilicium mit Hilfe eines inerten Fördergases durch eine Lanze möglichst tief in die Stahlschmelze eingeblasen. Da bei diesem Verfahren die Calciumkomponente im Überschuß zugegeben werden muß, entstehen erhebliche Calciumverluste durch Verdampfung (Stahl und Eisen 109 (1989) Nr. 16, Seite 40, H.K. Tönshoff u.a.).Injection techniques have become established worldwide for introducing calcium into the liquid steel. In the so-called TN process, fine-grained calcium silicon is blown through a lance as deeply as possible into the molten steel using an inert gas. Since the calcium component must be added in excess in this process, considerable calcium losses occur due to evaporation (Stahl und Eisen 109 (1989) No. 16, page 40, H.K. Tönshoff et al.).

Beim Verfahren der Stahlbehandlung mit Fülldrähten werden mit feinkörnigem Calcium gefüllte Hohldrähte mit hoher Geschwindigkeit in das Stahlbad eingeführt (DE-OS 37 39 155). Auf diese Weise kann man gezielt die je nach Charge benötigten unterschiedlichen Calciummengen in das Stahlbad einbringen. Man erreicht so gegenüber dem Blasverfahren bereits eine Verbesserung aufgrund der niedrigeren Aufwandmengen an Calcium.In the process of steel treatment with cored wires, hollow wires filled with fine-grained calcium are introduced into the steel bath at high speed (DE-OS 37 39 155). In this way, the different amounts of calcium required for each batch can be specifically introduced into the steel bath. Compared to the blowing process, an improvement is already achieved due to the lower calcium application rates.

Obwohl mit diesen bekannten Verfahren bereits deutliche Fortschritte in der Stahltechnologie erzielt wurden und insbesondere eine Verbesserung der mechanischen Eigenschaften des Stahls erreicht und eine günstige Beeinflussung der Vergießbarkeit von Stahlschmelzen, insbesondere beim Strangguß, erzielt wurden, sind die Kosten der Stahlbehandlung mit Calcium oder einer Calciumsilicium-Legierung nicht unbedeutend. Abgesehen davon können Calciumsilicium-Legierungen infolge der Siliciumaufnahme durch den Stahl nur bei siliciumhaltigen Stählen eingesetzt werden. Bei einer ganzen Reihe von Stahlsorten wie z.B. Kaltstauch- oder Tiefziehqualitäten, die keine oder nur eine sehr geringe Siliciumkonzentration enthalten, können nur siliciumarme bzw. siliciumfreie Calciumlegierungen oder -Verbindungen zur Stahlbehandlung verwendet werden. Normalerweise wird hierzu auf das recht teure metallische Calcium als Behandlungsmittel zurückgegriffen.Although significant progress has already been made in steel technology with these known processes, and in particular an improvement in the mechanical properties of the steel and a favorable influence on the castability of steel melts, in particular in continuous casting, have been achieved, the costs of steel treatment with calcium or a calcium silicon Alloy not insignificant. Apart from this, calcium-silicon alloys can only be used for steels containing silicon due to the absorption of silicon by the steel. With a whole range of steel types such as cold upsetting or deep drawing qualities, which contain no or only a very low silicon concentration, only low-silicon or silicon-free calcium alloys or compounds can be used for steel treatment. Normally, the rather expensive metallic calcium is used as a treatment agent.

Es wurde deshalb bereits versucht, mit Calciumcarbid, einem besonders kostengünstigen Calciumträger, gefüllte Drähte in Stahlschmelzen einzubringen. Da die Stahlschmelzen durch dieses Verfahren nie mehr als 10 ppm Calcium aufnahmen, wurden Anstrengungen in dieser Richtung eingestellt.For this reason, attempts have already been made to introduce wires filled with calcium carbide, a particularly inexpensive calcium carrier, into molten steel. Since the steel melts never absorbed more than 10 ppm calcium by this process, efforts in this direction were stopped.

Es bestand daher die Aufgabe, ein Mittel und Verfahren zur Calciumbehandlung von Stahl zur Verfügung zu stellen, das die Nachteile der bisher verwendeten Mittel nicht besitzt und das es ermöglicht, ausreichend hohe Konzentrationen an Calcium in der Stahlschmelze reproduzierbar einzustellen, so daß eine gezielte Verbesserung der mechanischen Eigenschaften des Stahls und eine günstige Beeinflussung seiner Vergießbarkeit erreicht werden.It was therefore an object to provide a means and process for calcium treatment of steel which does not have the disadvantages of the agents used hitherto and which makes it possible to reproducibly set sufficiently high concentrations of calcium in the steel melt, so that a targeted improvement in mechanical properties of the steel and a favorable influence on its castability can be achieved.

Gelöst wird diese Aufgabe erfindungsgemäß durch ein Mittel zur Calciumbehandlung von Stahl in Form eines Fülldrahtes auf einen metallischen Mantel und ein feinkörniges Füllmaterial auf Basis von Calciumcarbid aufweist, das dadurch gekennzeichnet ist, daß das Füllmaterial zusätzlich einen bei der Temperatur der Stahlschmelze gasabspaltenden bzw. gasentwickelnden Stoff in einer Menge von 2 bis 60 Gew.-%, berechnet auf das Gewicht des Calciumcarbids, enthält. Auf diese Weise lassen sich Gehalte von 20 bis 50 ppm Calcium im Stahl gezielt und mit wirtschaftlich interessanten Kosten einstellen.This object is achieved according to the invention by an agent for calcium treatment of steel in the form of a cored wire on a metallic sheath and a fine-grained filler material based on calcium carbide, which is characterized in that the filler material additionally contains a gas-releasing or gas-developing substance at the temperature of the steel melt in an amount of 2 to 60 wt .-%, calculated on the weight of calcium carbide. In this way, contents of 20 to 50 ppm calcium in the steel can be adjusted in a targeted manner and at economically interesting costs.

Der Fülldraht kann je nach Anwendungszweck und Größe der zur Verfügung stehenden Pfannen einen Durchmesser von 5 bis 20 mm aufweisen. Vorzugsweise wird ein Fülldraht mit einem Durchmesser von 9 bis 13 mm verwendet.The cored wire can have a diameter of 5 to 20 mm depending on the application and size of the pans available. A cored wire with a diameter of 9 to 13 mm is preferably used.

Als bei der Temperatur der Stahlschmelze gasabspaltende bzw. gasentwickelnde Stoffe, die dem Calciumcarbid beigemischt werden, haben sich z.B. bewährt: Kalkstein, ungebrannter Magnesit, gasabspaltende Kohlesorten wie Flammkohle, Polyethylen, Polypropylen. Als bei der Temperatur der Stahlschmelze gasentwickelnde Stoffe haben sich Magnesiummetall, Calciummetall und Calciumsilicium (CaSi) bewährt.As substances which release or develop gas at the temperature of the molten steel and which are admixed with the calcium carbide, e.g. proven: limestone, unfired magnesite, gas-releasing types of coal such as flame coal, polyethylene, polypropylene. Magnesium metal, calcium metal and calcium silicon (CaSi) have proven themselves as gas-developing substances at the temperature of the molten steel.

Bevorzugt wird eine Kohlesorte gewählt, die als getrocknetes Produkt bei der Temperatur der Stahlschmelze etwa 90 Gew.-% ihrer flüchtigen Bestandteile innerhalb von weniger als 60 Sekunden, bevorzugt weniger als 40 Sekunden, freisetzt. Je höher der Anteil an flüchtigen Bestandteilen der Kohle ist, umso höher ist im allgemeinen die Wirksamkeit der Behandlungsmittel. Besonders bevorzugt werden daher solche Kohlen verwendet, die wenigstens 25 Gew.-% flüchtige Bestandteile enthalten und nach Eintritt in die Stahlschmelze ein Gasvolumen von mindestens 150 NL/kg entwickeln. Kohlen, die diese Bedingungen erfüllen sind insbesondere Braunkohlen, Flammkohle, Gasflammkohle, Gaskohle und Fettkohle.A type of coal is preferably selected which, as a dried product, releases about 90% by weight of its volatile constituents at the temperature of the steel melt within less than 60 seconds, preferably less than 40 seconds. In general, the higher the volatile content of the coal, the higher the effectiveness of the treatment agents. Coals which contain at least 25% by weight of volatile constituents and which, after entering the molten steel, develop a gas volume of at least 150 NL / kg are particularly preferably used. Coals that meet these conditions are, in particular, brown coal, flame coal, gas flame coal, gas coal and fat coal.

Die Korngröße der Kohle wird etwa auf die des Calciumcarbids eingestellt. Vorzugsweise enthält das Füllmaterial 85 bis 98 Gew.-% Calciumcarbid und 15 bis 2 Gew.-% einer getrockneten Kohle mit einem Feuchtigkeitsgehalt < 0,5 %. In einer zweckmäßigen Ausführungsform enthält das Füllmaterial 90 bis 95 Gew.-% Calciumcarbid und 10 bis 5 Gew.-% Flammkohle. Calciumcarbid als Calciumquelle wird in Form des technischen Calciumcarbids mit Gehalten von 50 bis 85 Gew.-% CaC₂ verwendet. Bevorzugt wird hochprozentiges Calciumcarbid von 75 bis 85 Gew.-% CaC₂ eingesetzt, da hierdurch die Calciumkonzentration entsprechend hoch ist und der in die Schmelze eingebrachte Schlackenanteil sich verringert. Die Korngröße des verwendeten Calciumcarbids sollte zweckmäßig < 1 mm, bevorzugt < 0,5 mm, sein.The grain size of the coal is adjusted approximately to that of the calcium carbide. The filler material preferably contains 85 to 98% by weight of calcium carbide and 15 to 2% by weight of a dried coal with a moisture content of <0.5%. In an expedient embodiment, the filling material contains 90 to 95% by weight calcium carbide and 10 to 5% by weight flame carbon. Calcium carbide as calcium source is used in the form of technical calcium carbide with contents of 50 to 85 wt .-% CaC₂. High-percentage calcium carbide of 75 to 85% by weight CaC₂ is preferably used, since this means that the calcium concentration is correspondingly high and the amount of slag introduced into the melt is reduced. The grain size of the calcium carbide used should advantageously be <1 mm, preferably <0.5 mm.

Als bei der Temperatur der Stahlschmelze gasentwickelnde Stoffe haben Calciummetall oder Calciumsilicium den Vorteil, daß sie gleichzeitig Calcium liefern. Hierbei werden handelsübliche, technische Produkte eingesetzt, wobei die Reinheit des Calciummetalls etwa 95 % beträgt, die Calciumsilicium-Legierung normalerweise 30 Gew.-% Calcium und 60 Gew.-% Silicium enthält und der Rest aus Eisen und herstellungsbedingten Verunreinigungen besteht. Im erfindungsgemäßen Mittel können so 5 bis 60 Gew.-% des Calciumcarbids im Füllmaterial durch Calciumsilicium ersetzt werden, so daß der Anteil an Calciumcarbid 40 bis 95 Gew.-% beträgt. Bevorzugt wird eine Zusammensetzung des Füllmaterials aus 40 bis 80 Gew.-% Calciumcarbid und 60 bis 20 Gew.-% Calciumsilicium. Hiermit wird das Einbringen von Silicium in den Stahl weitgehend reduziert, Turbulenz und Verdampfungsverluste beim Einspulen des Fülldrahtes werden durch den Verdünnungseffekt des Calciumcarbids geregelt. Die Korngrößen des Calciumcarbids und des Calciums bzw. der Calciumsilicium-Legierung sollen etwa im gleichen Bereich liegen und < 1 mm, bevorzugt < 0,5 mm, betragen.As gas-evolving substances at the temperature of the molten steel, calcium metal or calcium silicon have the advantage that they simultaneously provide calcium. Commercial technical products are used here, the purity of the calcium metal being approximately 95%, the calcium silicon alloy normally containing 30% by weight calcium and 60% by weight silicon, and the rest consisting of iron and production-related impurities. In the agent according to the invention, 5 to 60% by weight of the calcium carbide in the filling material can be replaced by calcium silicon, so that the proportion of calcium carbide is 40 to 95% by weight. A composition of the filling material of 40 to 80% by weight of calcium carbide and 60 to 20% by weight of calcium silicon is preferred. This largely reduces the introduction of silicon into the steel; turbulence and evaporation losses when winding in the cored wire are regulated by the dilution effect of the calcium carbide. The grain sizes of the calcium carbide and the calcium or the calcium silicon alloy should be approximately in the same range and should be <1 mm, preferably <0.5 mm.

Die Behandlung der Stahlschmelze mit dem erfindungsgemäßen Mittel kann unter Zuhilfenahme einer handelsüblichen Einspulvorrichtung sicher und problemlos durchgeführt werden. Entsprechend der gewünschten Calciumkonzentration im Stahl, die im allgemeinen zwischen 20 bis 50 ppm betragen soll, werden etwa 0,6 kg Füllmaterial, entsprechend etwa 3,5 m Fülldraht eines Durchmessers von 13 mm pro Tonne zu behandelnder Stahlschmelze eingesetzt. Hierbei werden Einspulgeschwindigkeiten von 100 bis 300 m/Min., vorzugsweise von 200 bis 250 m/Min., angewendet. Unter diesen Bedingungen wird das Mittel tief genug in die Stahlschmelze eingebracht. Die entstehende Turbulenz sorgt dafür, daß die Calciumkomponente bestmöglich genutzt und die Stahlschmelze gut durchmischt und homogenisiert wird.The treatment of the molten steel with the agent according to the invention can be carried out safely and easily with the aid of a commercially available winding device. Corresponding to the desired calcium concentration in the steel, which should generally be between 20 and 50 ppm, approximately 0.6 kg of filler material, corresponding to approximately 3.5 m of cored wire with a diameter of 13 mm per ton of steel melt to be treated, is used. Here, winding speeds of 100 to 300 m / min., Preferably from 200 to 250 m / min., Are used. Under these conditions, the agent is introduced deep enough into the molten steel. The resulting turbulence ensures that the calcium component is used in the best possible way and that the molten steel is mixed and homogenized well.

Die nachfolgenden Beispiele sollen die Erfindung näher erläutern.The following examples are intended to explain the invention in more detail.

BeispieleExamples

In den nachfolgenden Beispielen (Tabelle 1) wird die Behandlung von 70 t-Chargen von Stahlschmelzen in einer Gießpfanne beschrieben, wobei die Temperatur der Stahlschmelze etwa 1620°C betrug.The following examples (Table 1) describe the treatment of 70 t batches of molten steel in a ladle, the temperature of the molten steel being approximately 1620 ° C.

Die behandelten Stahlschmelzen sollen 25 bis 40 ppm Calcium enthalten, um auf einer Knüppelstranggußanlage vergossen werden und als niedrig legierter Edelbaustahl Verwendung finden zu können.The treated steel melts should contain 25 to 40 ppm calcium in order to be cast on a billet caster and to be used as a low-alloy stainless steel.

Für die als Beispiel herangezogenen 70 t-Chargen wurde jeweils ein Fülldraht von 13 mm Durchmesser verwendet, der mit einer Geschwindigkeit von 180 bis 200 m/Min. in die Stahlschmelze eingespult wurde.

Figure imgb0001
For the 70 t batches used as an example, a cored wire with a diameter of 13 mm was used, which with a speed of 180 to 200 m / min. was wound into the molten steel.
Figure imgb0001

Claims (11)

Mittel zur Calciumbehandlung von Stahl in Form eines Fülldrahtes, der einen metallischen Mantel und ein feinkörniges Füllmaterial auf Basis von Calciumcarbid aufweist,
dadurch gekennzeichnet,
daß das Füllmaterial zusätzlich einen bei der Temperatur der Stahlschmelze gasabspaltenden bzw. gasentwickelnden Stoff in einer Menge von 2 bis 60 Gew.-%, berechnet auf das Gewicht des Calciumcarbids, enthält.Agent for calcium treatment of steel in the form of a cored wire, which has a metallic sheath and a fine-grained filler material based on calcium carbide,
characterized,
that the filler material additionally contains a substance which splits off or develops gas at the temperature of the molten steel in an amount of 2 to 60% by weight, calculated on the weight of the calcium carbide. Mittel nach Anspruch 1,
dadurch gekennzeichnet,
daß der Fülldraht einen Durchmesser von 5 bis 20 mm, vorzugsweise von 9 bis 13 mm, aufweist.Means according to claim 1,
characterized,
that the cored wire has a diameter of 5 to 20 mm, preferably 9 to 13 mm. Mittel nach den Ansprüchen 1 oder 2,
dadurch gekennzeichnet,
daß das Füllmaterial 85 bis 98 Gew.-% Calciumcarbid und 15 bis 2 Gew.-% einer getrockneten Kohle mit einem Feuchtigkeitsgehalt < 0,5 % enthält.Agent according to claims 1 or 2,
characterized,
that the filler contains 85 to 98 wt .-% calcium carbide and 15 to 2 wt .-% of a dried coal with a moisture content <0.5%. Mittel nach Anspruch 3,
dadurch gekennzeichnet,
daß das Füllmaterial 90 bis 95 Gew.-% Calciumcarbid und 10 bis 5 Gew.-% Flammkohle enthält.Means according to claim 3,
characterized,
that the filler contains 90 to 95 wt .-% calcium carbide and 10 to 5 wt .-% flame carbon. Mittel nach einem der Ansprüche 1 bis 4,
dadurch gekennzeichnet,
daß das Füllmaterial eine Kohle enthält, die bei der Temperatur der Stahlschmelze etwa 90 Gew.-% der flüchtigen Bestandteile innerhalb von weniger als 60 Sekunden, bevorzugt weniger als 40 Sekunden, freisetzt.Agent according to one of claims 1 to 4,
characterized,
that the filling material contains a carbon which releases about 90% by weight of the volatile constituents at the temperature of the molten steel within less than 60 seconds, preferably less than 40 seconds. Mittel nach den Ansprüchen 1 und 2,
dadurch gekennzeichnet,
daß das Füllmaterial aus 95 bis 99,5 Gew.-% Calciumcarbid und 0,5 bis 5 Gew.-% Polyethylen besteht.Agent according to claims 1 and 2,
characterized,
that the filler consists of 95 to 99.5 wt .-% calcium carbide and 0.5 to 5 wt .-% polyethylene. Mittel nach den Ansprüchen 1 und 2,
dadurch gekennzeichnet,
daß das Füllmaterial aus 40 bis 95 Gew.-% Calciumcarbid, aus 5 bis 60 Gew.-% Calciumsilicium besteht.Agent according to claims 1 and 2,
characterized,
that the filler consists of 40 to 95 wt .-% calcium carbide, from 5 to 60 wt .-% calcium silicon. Mittel nach Anspruch 7,
dadurch gekennzeichnet,
daß das Füllmaterial aus 40 bis 70 Gew.-% Calciumcarbid und 30 bis 60 Gew.-% Calciumsilicium besteht.Means according to claim 7,
characterized,
that the filler consists of 40 to 70 wt .-% calcium carbide and 30 to 60 wt .-% calcium silicon. Mittel nach einem der Ansprüche 1 bis 8,
dadurch gekennzeichnet,
daß die Korngröße des Bestandteile des Füllmaterials kleiner 1 mm, vorzugsweise kleiner 0,5 mm, ist.Agent according to one of claims 1 to 8,
characterized,
that the grain size of the components of the filling material is less than 1 mm, preferably less than 0.5 mm. Verfahren zur Behandlung von Stahlschmelzen, dadurch gekennzeichnet, daß man das Mittel nach einem der Ansprüche 1 bis 9 in die Schmelze einführt.Process for the treatment of steel melts, characterized in that the agent according to one of Claims 1 to 9 is introduced into the melt. Verfahren nach Anspruch 10,
dadurch gekennzeichnet,
daß man den Fülldraht mit einer Geschwindigkeit von 100 bis 300 m/Min. in die Stahlschmelze einspult.A method according to claim 10,
characterized,
that the cored wire at a speed of 100 to 300 m / min. wound into the molten steel.
EP19920106619 1990-10-19 1992-04-16 Agent and process for calcium treating of steel Expired - Lifetime EP0565763B1 (en)

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DE59207996T DE59207996D1 (en) 1992-04-16 1992-04-16 Means and methods for the calcium treatment of steel
AT92106619T ATE148504T1 (en) 1992-04-16 1992-04-16 MEANS AND METHOD FOR CALCIUM TREATMENT OF STEEL

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DE4033183A1 (en) * 1990-10-19 1992-04-23 Sueddeutsche Kalkstickstoff MEANS AND METHOD FOR CALCIUM TREATMENT OF STEEL
DE4236727C2 (en) * 1992-10-30 1997-02-06 Sueddeutsche Kalkstickstoff Melting agent and its use
DE19728771C2 (en) * 1997-07-05 2000-11-02 Daimler Chrysler Ag Process for producing a high-carbon, niobium-alloyed gray cast iron alloy using an alloying aid
GB202219049D0 (en) * 2022-12-16 2023-02-01 Injection Alloys Ltd Wire for refining molten metal

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US4094666A (en) * 1977-05-24 1978-06-13 Metal Research Corporation Method for refining molten iron and steels
US4159906A (en) * 1972-10-27 1979-07-03 Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft Method and composition for the desulfurization of molten metals
DE3042489A1 (en) * 1980-11-11 1982-06-16 Dr.-Ing. Edward Jerome Wescosville Pa. Dunn jun. Refining steel with lightweight volatile scavenging agents - in form of compressed body having controlled dissolution rate to reduce smoking
DE3739155A1 (en) * 1987-11-19 1989-06-01 Sueddeutsche Kalkstickstoff Calcium-containing addition for steel melts
DE4033183A1 (en) * 1990-10-19 1992-04-23 Sueddeutsche Kalkstickstoff MEANS AND METHOD FOR CALCIUM TREATMENT OF STEEL

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US4159906A (en) * 1972-10-27 1979-07-03 Suddeutsche Kalkstickstoff-Werke Aktiengesellschaft Method and composition for the desulfurization of molten metals
US4094666A (en) * 1977-05-24 1978-06-13 Metal Research Corporation Method for refining molten iron and steels
DE3042489A1 (en) * 1980-11-11 1982-06-16 Dr.-Ing. Edward Jerome Wescosville Pa. Dunn jun. Refining steel with lightweight volatile scavenging agents - in form of compressed body having controlled dissolution rate to reduce smoking
DE3739155A1 (en) * 1987-11-19 1989-06-01 Sueddeutsche Kalkstickstoff Calcium-containing addition for steel melts
DE4033183A1 (en) * 1990-10-19 1992-04-23 Sueddeutsche Kalkstickstoff MEANS AND METHOD FOR CALCIUM TREATMENT OF STEEL

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DE4033183A1 (en) 1992-04-23

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