DE1177898B - Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate - Google Patents

Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate

Info

Publication number
DE1177898B
DE1177898B DED32898A DED0032898A DE1177898B DE 1177898 B DE1177898 B DE 1177898B DE D32898 A DED32898 A DE D32898A DE D0032898 A DED0032898 A DE D0032898A DE 1177898 B DE1177898 B DE 1177898B
Authority
DE
Germany
Prior art keywords
alkali
nitriding
iron alloys
cyanate
cyanide
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.)
Pending
Application number
DED32898A
Other languages
German (de)
Inventor
Carl Albrecht
Dr Johannes Mueller
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
Original Assignee
Degussa GmbH
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Degussa GmbH filed Critical Degussa GmbH
Priority to DED32898A priority Critical patent/DE1177898B/en
Publication of DE1177898B publication Critical patent/DE1177898B/en
Pending legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/40—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions
    • C23C8/42—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions only one element being applied
    • C23C8/48—Nitriding
    • C23C8/50—Nitriding of ferrous surfaces
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C8/00—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
    • C23C8/40—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions
    • C23C8/42—Solid state diffusion of only non-metal elements into metallic material surfaces; Chemical surface treatment of metallic material by reaction of the surface with a reactive gas, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using liquids, e.g. salt baths, liquid suspensions only one element being applied
    • C23C8/48—Nitriding

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Description

Verfahren zum Nitrieren von Metallen, insbesondere Eisenlegierungen, in alkalicyanid-und alkalicyanabhadtigen Salzbädern Zusatz zur Anmeldung: D 30396 VI b / 48 b -Auslegeschrift 1149 035 Die Hauptpatentanmeldung betrifft ein Verfahren zum Nitrieren von Metallen, insbesondere Eisenlegierungen, in alkalicyanid- und alkalicyanathaltigen Salzbädern, nach dem eine wesentliche Steigerung der Nitrierwirkung dadurch erreicht werden soll, daß durch das Bad Luft oder andere oxydierend wirkende Gase in feiner Verteilung hindurchgeleitet werden.Process for nitriding metals, in particular iron alloys, in alkali cyanide and alkali cyanide-containing salt baths Addition to registration: D 30396 VI b / 48 b - Auslegeschrift 1149 035 according to which a substantial increase in the nitriding effect is to be achieved in that air or other oxidizing gases are passed through the bath in fine distribution.

Bei bekannten Nitrierverfahren werden Werkstücke bei Temperaturen zwischen etwa 500 und 600°C in ein Salzbad getaucht, welches aus Cyanid und Cyanat besteht. Durch das Hindurchleiten von Luft durch das Salzbad kann hierbei eine wesentliche Verbesserung der Nitrierwirkung erzielt werden, indem beispielsweise bei einem Ofen von 60 cm Durchmesser und 1 m Tiefe mit einem Bad von 350/, KCNO und 400/, NaCN, Rest Alkalikarbonat, der ohne Einleitung von Luft eine Verbindungszone von 2 bis 3 #t Dicke ergibt, beim Hindurchleiten von Luft Verbindungszonen von 8 bis 12 p, Dicke erzielt werden.In known nitriding processes, workpieces are immersed in a salt bath consisting of cyanide and cyanate at temperatures between about 500 and 600 ° C. By passing air through the salt bath, a significant improvement in the nitriding effect can be achieved by using, for example, a furnace with a diameter of 60 cm and a depth of 1 m with a bath of 350 /, KCNO and 400 /, NaCN, the rest of the alkali carbonate without Introduction of air results in a connection zone of 2 to 3 μm thick, when air is passed through connection zones of 8 to 12 μm thick are achieved.

In der Hauptpatentanmeldung ist vorgeschlagen, durch Dosieren der hindurchgeleiteten Luft- bzw. Gasmenge die Stärke der Nitrierwirkung zu regeln. Im allgemeinen wird man aus wirtschaftlichen Gründen die Nitrierwirkung auf das höchstmögliche Maß steigern.In the main patent application is proposed by metering the to regulate the strength of the nitriding effect. In general, for economic reasons, the nitriding effect on the Increase as much as possible.

Es wurde nun gefunden, daß es besonders zweckmäßig ist, die Bemessung der Gasmenge mehr in Abhängigkeit von dem Durchmesser des Badbehälters als von der Tiefe desselben vorzunehmen.It has now been found that it is particularly useful to measure the amount of gas more depending on the diameter of the bath container than on the Depth of the same to make.

Eine optimale Nitrierwirkung wird insbesondere dann erreicht, wenn die Luftmenge L nach folgender Formel bemessen wird: In dieser Formel bedeutet r den Radius, d die Tiefe des Bades in Zentimetern und 1/h = Liter pro Stunde.An optimal nitriding effect is achieved in particular when the air volume L is measured according to the following formula: In this formula, r means the radius, d the depth of the bath in centimeters and 1 / h = liters per hour.

Nach dieser Formel ergibt sich beispielsweise bei einem Badbehälter von 60 cm Durchmesser und 1 m Tiefe eine stündliche Luftmenge von 600 bis 8001. Mit einer derartigen Bemessung läßt sich eine optimale Nitrierwirkung in bezug auf die Nitriertiefe und die Behandlungszeit im Salzbad erreichen. Ein Nachfüllen des Bades ist nur mit Cyanid notwendig, da dieses während des Betriebes des Bades zu Cyanat oxydiert wird.This formula results in a bath tank, for example 60 cm in diameter and 1 m deep an hourly air volume of 600 to 8001. With such a dimensioning, an optimal nitriding effect can be achieved with respect to reach the nitriding depth and the treatment time in the salt bath. Refilling the Bath is only necessary with cyanide, as this increases during operation of the bath Cyanate is oxidized.

Claims (2)

Patentansprüche: 1. Verfahren zum Nitrieren von Metallen, insbesondere Eisenlegierungen, in alkalicyanid- und alkalicyanathaltigen Salzbädern, bei dem durch das Bad Luft oder andere oxydierend wirkende Gase in feiner Verteilung hindurchgeleitet werden, gemäß Patentanmeldung D 30396 VIb/48b (deutsche Auslegeschrift 1 149 035), d a d u r c h g e k e n n z e i c h n e t, daß die Gasmenge stärker in Abhängigkeit vom Durchmesser des Badbehälters als in Abhängigkeit von der Tiefe desselben bemessen wird. Claims: 1. Process for nitriding metals, in particular Iron alloys, in salt baths containing alkali cyanide and alkali cyanate, in which air or other oxidizing gases passed through the bath in fine distribution according to patent application D 30396 VIb / 48b (German Auslegeschrift 1 149 035), d a d u r c h e k e n n n z e i c h n e t that the amount of gas is more dependent measured by the diameter of the bath container as a function of the depth of the same will. 2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß die Luftmenge nach der Formel bemessen wird, wobei r den Radius in Zentimetern, d die Tiefe und 1/h = Liter pro Stunde bedeutet. In Betracht gezogene Druckschriften: B u 11 e n s, »Steel and its Heattreatmentu, Bd. II, 1948, S. 50, Abs. 4.2. The method according to claim 1, characterized in that the amount of air according to the formula is measured, where r is the radius in centimeters, d is the depth and 1 / h = liters per hour. Considered publications: B u 11 ens, »Steel and its Heattreatmentu, Vol. II, 1948, p. 50, para. 4.
DED32898A 1960-03-19 1960-03-19 Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate Pending DE1177898B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DED32898A DE1177898B (en) 1960-03-19 1960-03-19 Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DED32898A DE1177898B (en) 1960-03-19 1960-03-19 Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate

Publications (1)

Publication Number Publication Date
DE1177898B true DE1177898B (en) 1964-09-10

Family

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Family Applications (1)

Application Number Title Priority Date Filing Date
DED32898A Pending DE1177898B (en) 1960-03-19 1960-03-19 Process for nitriding metals, in particular iron alloys, in salt baths containing alkali cyanide and alkali cyanate

Country Status (1)

Country Link
DE (1) DE1177898B (en)

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
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