DE858423C - Annealing of malleable cast iron in liquid baths - Google Patents
Annealing of malleable cast iron in liquid bathsInfo
- Publication number
- DE858423C DE858423C DE1948P0027216 DEP0027216D DE858423C DE 858423 C DE858423 C DE 858423C DE 1948P0027216 DE1948P0027216 DE 1948P0027216 DE P0027216 D DEP0027216 D DE P0027216D DE 858423 C DE858423 C DE 858423C
- Authority
- DE
- Germany
- Prior art keywords
- annealing
- cast iron
- malleable cast
- glass
- liquid baths
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D5/00—Heat treatments of cast-iron
- C21D5/04—Heat treatments of cast-iron of white cast-iron
- C21D5/06—Malleabilising
- C21D5/08—Malleabilising with oxidation of carbon
- C21D5/10—Malleabilising with oxidation of carbon in gaseous agents
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/34—Methods of heating
- C21D1/44—Methods of heating in heat-treatment baths
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Glass Compositions (AREA)
Description
Glühfrischen von Temperrohguß in flüssigen Bädern Das Tempern von Temperrohguß mit dem Ziel der Herstellung von schwarzem Temperguß in Salzbädern ist bekannt. Bekannt ist auch, daß beim Anlassen oder Glühen von Stählen in Salzbädern eine Oxydation auftritt, die durch Zusatz kohlenstoffabgebender Mittel zum Salzbad verhindert werden kann. Man kann aber auch umgekehrt derartigen Salzschmelzen oder auch Glasflüssen sauerstoffabgebende Mittel zusetzen, um eine Entkohlungsgeschwindigkeit zu erhalten, welche bei technischen Temperprozessen auswertbar ist. Unter Salzen versteht man bekanntlich eine Klasse von Stoffen, zu denen gewöhnliches Salz oder Natriumchlorid, Kaliumnitrat, Natriumsulfat, Kaliumchlorid usw. gehören. Unter dem Wort Glasflüssen werden Verbindungen von Kieselsäure, Phosphorsäure und Borsäure mit Metallradikalen verstanden. Vorliegende Erfindung bezieht sich auf die Erhöhung der Oxydation von Salzschmelzen oderGlasflüssen und ist dadurch gekennzeichnet, daß Salzschmelzen sauerstoffabgebende Salze, z. B. Nitrate, oder aber Superoxyde, Glasflüssen dagegen Schwermetalloxyde zugesetzt werden in einer Menge, welche die Verwertung dieser Mischungen für das europäische Glühfrischen von Temperrohguß ermöglicht.Annealing refining of malleable cast iron in liquid baths Malleable cast iron with the aim of producing black malleable cast iron in salt baths is known. It is also known that when tempering or annealing steels in salt baths an oxidation occurs due to the addition of carbon-emitting agents to the salt bath can be prevented. But you can also vice versa such molten salts or also add oxygen-releasing agents to glass fluxes to reduce the rate of decarburization to obtain, which can be evaluated in technical tempering processes. Under salts is known to mean a class of substances to which ordinary salt or Include sodium chloride, potassium nitrate, sodium sulfate, potassium chloride, etc. Under the Word glass rivers are compounds of silica, phosphoric and boric acid understood with metal radicals. The present invention relates to elevation the oxidation of molten salts or glass fluxes and is characterized by that molten salts are oxygen-releasing salts, e.g. B. nitrates, or super oxides, In contrast, heavy metal oxides are added to glass rivers in an amount which corresponds to the Utilization of these mixtures for the European annealing refining of malleable cast iron made possible.
Als Zusatz für Salzschmelzen, z. B. den für die Wärmebehandlung von Stählen u. a. üblichen Chlorid- oder Fluoridgemischen (Natrium-Kalium-Barium-Chloriden bzw. -Fluo-riden), eignen sich erfindungsgemäß sauerstoffabgebende Salze, wie Nitrate, z. B. Kaliumnitrat, oder aber Superoxyde, z. B. Bariumsuperoxyd. Als Zusätze für Glasflüsse (Silicate allein oder im Gemisch mit Boraten) eignensich als Oxyde der Schwermetalle z. B. solche des Eisens, -Mangans oder des Kupfers. Die Borate haben dabei die Aufgabe, notwendigenfalls den Schmelzpunkt der Glasflüsse so zu erniedrigen, daß das Tempern im Existenzgebiet des Austenits vor sich gehen kann (d. h. oberhalb etwa iooo° C).As an additive for molten salts, e.g. B. for the heat treatment of Steels, etc. common chloride or fluoride mixtures (sodium-potassium-barium-chlorides or fluorides), according to the invention, oxygen-releasing salts such as nitrates, z. B. potassium nitrate, or super oxides, z. B. barium peroxide. As accessories for Glass fluxes (silicates alone or in a mixture with borates) are suitable as Oxides of heavy metals z. B. those of iron, manganese or copper. the Borates have the task of, if necessary, the melting point of the glass flows to be lowered in such a way that the tempering takes place in the area of existence of the austenite can (i.e. above about 10,000 ° C).
Die Arbeitsweise gemäß vorliegender Erfindung wird wesentlich .wirtschaftlicher (kürzere Glühfrischzeiten), wenn man den Siliciumgehalt des Temperrohgusses unter etwa o,5 %, vorzugsweise zwischen o,2 bis o,3 % Si, hält.The procedure according to the present invention is much more economical (shorter annealing refining times), if you take the silicon content of the malleable cast iron below about 0.5%, preferably between 0.2 to 0.3% Si, holds.
Man kann derartige Salzschmelzen oder Glasflüsse immer wieder dadurch regenerieren, daß man nach Beendigung des Glühfrischens Luft, sauerstoffabgebende Gase oder Abgase durch die Salzschmelzen bzw. die Glasflüsse leitet. Man kann dieses Durchleiten von Luft, sauerstoffabgebenden Gasen oder Abgasen aber auch während des Glühfrischvorganges vornehmen.You can use this kind of molten salt or glass flow again and again regenerate that, after annealing-freshening, air, which releases oxygen Directs gases or exhaust gases through the molten salts or the glass flows. One can do this Passing air, oxygen-releasing gases or exhaust gases through, but also during of the annealing process.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1948P0027216 DE858423C (en) | 1948-12-28 | 1948-12-28 | Annealing of malleable cast iron in liquid baths |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1948P0027216 DE858423C (en) | 1948-12-28 | 1948-12-28 | Annealing of malleable cast iron in liquid baths |
Publications (1)
Publication Number | Publication Date |
---|---|
DE858423C true DE858423C (en) | 1952-12-08 |
Family
ID=580251
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE1948P0027216 Expired DE858423C (en) | 1948-12-28 | 1948-12-28 | Annealing of malleable cast iron in liquid baths |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE858423C (en) |
-
1948
- 1948-12-28 DE DE1948P0027216 patent/DE858423C/en not_active Expired
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