EP0054962B1 - Procédé non polluant de carburation de l'acier en bain de sel fondu - Google Patents

Procédé non polluant de carburation de l'acier en bain de sel fondu Download PDF

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Publication number
EP0054962B1
EP0054962B1 EP81110690A EP81110690A EP0054962B1 EP 0054962 B1 EP0054962 B1 EP 0054962B1 EP 81110690 A EP81110690 A EP 81110690A EP 81110690 A EP81110690 A EP 81110690A EP 0054962 B1 EP0054962 B1 EP 0054962B1
Authority
EP
European Patent Office
Prior art keywords
salt
carburizing
bath
alkaline earth
carburizing steel
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
Application number
EP81110690A
Other languages
German (de)
English (en)
Other versions
EP0054962A1 (fr
Inventor
Heinrich Dipl.-Ing. Michel
Alexander Pralea
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 AT81110690T priority Critical patent/ATE12951T1/de
Publication of EP0054962A1 publication Critical patent/EP0054962A1/fr
Application granted granted Critical
Publication of EP0054962B1 publication Critical patent/EP0054962B1/fr
Expired legal-status Critical Current

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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
    • C23C8/52—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 more than one element being applied in one step
    • C23C8/54—Carbo-nitriding
    • C23C8/56—Carbo-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
    • C23C8/44—Carburising
    • C23C8/46—Carburising of ferrous surfaces

Definitions

  • the present invention relates to a method for carburizing steel in a salt bath, whereby a high cyanide content in the bath is progressively avoided.
  • Carburization processes for steel in a salt bath are available in various versions in the prior art, however the processes in the prior art generally have the disadvantage of having a high cyanide content in the salt bath.
  • This high cyanide content in the baths is questionable for environmental reasons.
  • a steel crucible with a capacity of 80 l is filled with 50 kg of starting salt, which consists of 60% barium chloride, 20% sodium chloride and 20% potassium chloride.
  • This filling is brought to a temperature of 800 ° C by means of a heating system operated with natural gas, whereby a completely homogeneous melt is created.
  • the steel crucible filling is then heated to 900 ° C and then the workpieces, namely gearwheels (consisting of case hardening steel made of 20 MnCr 5 alloy) with a unit weight of 1 kg, are placed on a steel wire in the aforementioned melt and carburized within 4 hours.
  • gearwheels consisting of case hardening steel made of 20 MnCr 5 alloy
  • the case hardening depth is 0.83 mm.
  • the hardness is given in hardness HV1 and the edge distance in mm.
  • the cyanide content is checked by sampling and titration with nickel sulfate and murexide as an indicator.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Heat Treatment Of Articles (AREA)
  • Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
  • Treatment Of Steel In Its Molten State (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)

Claims (9)

1. Procédé de carburation d'acier en bain de sel, caractérisé par les étapes suivantes :
a) on remplit le récipient de traitement d'un sel de complément qui est formé d'un mélange d'halogénure alcalin et d'halogénure alcalino-terreux ;
b) on provoque la fusion du sel de complément ;
c) on ajoute du sel additionnel qui est formé d'un mélange d'halogénure alcalino-terreux, de ferrocyanure alcalin et de cyanate alcalin, l'halogénure alcalino-terreux du sel additionnel concordant avec l'halogénure alcalino-terreux du sel de complément ;
d) on chauffe le contenu du récipient de traitement à la température d'application ;
e) on plonge la pièce à traiter dans le contenu du récipient de traitement, c'est-à-dire dans le bain de carburation et on l'y laisse jusqu'à ce que la profondeur de carburation désirée soit atteinte ;
f) on retire la pièce du bain de carburation et, selon la nature du matériau, on la trempe dans le milieu de trempe approprié.
2. Procédé de carburation d'acier en bain de sel, caractérisé en ce qu'à l'étape a), à la température normale, on remplit le récipient de traitement de sel de complément, à raison de 80 % en poids de la quantité totale de remplissage désirée.
3. Procédé de carburation d'acier en bain de sel selon la revendication 1, caractérisé en ce qu'à l'étape b), on chauffe le sel complémentaire à une température d'environ 800 °C à laquelle se produit la fusion complète.
4. Procédé de carburation d'acier en bain de sel selon la revendication 1, caractérisé en ce qu'à l'étape c), on ajoute 20 % en poids de sel additionnel qui est formé d'halogénure alcalino-terreux, de ferrocyanure de potassium ou de ferrocyanure de sodium ainsi que de cyanate de potassium ou de cyanate de sodium.
5. Procédé de carburation d'acier en bain de sel selon la revendication 1, caractérisé en ce que l'on chauffe le bain à une température d'application d'environ 800 à 1 020 °C.
6. Procédé de carburation d'acier en bain de sel selon la revendication 1, caractérisé en ce que l'on plonge la pièce à traiter dans le bain de carburation et qu'on l'y laisse selon la profondeur de carburation désirée.
7. Procédé de carburation d'acier en bain de sel selon l'une quelconque des revendications 1 à 6, caractérisé en ce que l'on commande et/ou règle la température de carburation.
8. Procédé de carburation d'acier en bain de sel selon la revendication 1, caractérisé en ce qu'à l'étape f), on trempe la pièce, retirée du bain, dans l'eau, dans l'huile ou dans le bain de sel de trempe.
9. Procédé de carburation d'acier en bain de sel selon l'une quelconque des revendications 1 à 8, caractérisé en ce que l'on effectue le réglage de la faible teneur en cyanure du bain en introduisant le sel additionnel.
EP81110690A 1980-12-23 1981-12-22 Procédé non polluant de carburation de l'acier en bain de sel fondu Expired EP0054962B1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT81110690T ATE12951T1 (de) 1980-12-23 1981-12-22 Umweltfreundliches verfahren zum aufkohlen von stahl im salzbad.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3048607 1980-12-23
DE3048607A DE3048607C2 (de) 1980-12-23 1980-12-23 Cyanidfreies Verfahren zum Aufkohlen von Stahl und Zugabesalz zur Durchführung des Verfahrens

Publications (2)

Publication Number Publication Date
EP0054962A1 EP0054962A1 (fr) 1982-06-30
EP0054962B1 true EP0054962B1 (fr) 1985-04-24

Family

ID=6120037

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81110690A Expired EP0054962B1 (fr) 1980-12-23 1981-12-22 Procédé non polluant de carburation de l'acier en bain de sel fondu

Country Status (4)

Country Link
EP (1) EP0054962B1 (fr)
AT (1) ATE12951T1 (fr)
CH (1) CH647002A5 (fr)
DE (2) DE3048607C2 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6093303A (en) * 1998-08-12 2000-07-25 Swagelok Company Low temperature case hardening processes
US6165597A (en) * 1998-08-12 2000-12-26 Swagelok Company Selective case hardening processes at low temperature

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6547888B1 (en) 2000-01-28 2003-04-15 Swagelok Company Modified low temperature case hardening processes
DE102006026883B8 (de) 2006-06-09 2007-10-04 Durferrit Gmbh Verfahren zum Härten von Edelstahl und Salzschmelze zur Durchführung des Verfahrens
DE102007051949B3 (de) * 2007-10-31 2009-03-12 Durferrit Gmbh Verfahren zum Härten von Oberflächen von Werkstücken aus Edelstahl und Verwendung einer Salzschmelze zur Durchführung des Verfahrens

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1053243A (fr) * 1900-01-01
US1952090A (en) * 1931-07-11 1934-03-27 American Cyanamid Co Case-hardening metals

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6093303A (en) * 1998-08-12 2000-07-25 Swagelok Company Low temperature case hardening processes
US6165597A (en) * 1998-08-12 2000-12-26 Swagelok Company Selective case hardening processes at low temperature

Also Published As

Publication number Publication date
DE3048607C2 (de) 1983-07-07
CH647002A5 (de) 1984-12-28
ATE12951T1 (de) 1985-05-15
DE3048607A1 (de) 1982-07-01
DE3170212D1 (en) 1985-05-30
EP0054962A1 (fr) 1982-06-30

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