EP0077926B1 - Process to suppress surface deposits during salt bath nitriding of structural parts - Google Patents
Process to suppress surface deposits during salt bath nitriding of structural parts Download PDFInfo
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- EP0077926B1 EP0077926B1 EP82108892A EP82108892A EP0077926B1 EP 0077926 B1 EP0077926 B1 EP 0077926B1 EP 82108892 A EP82108892 A EP 82108892A EP 82108892 A EP82108892 A EP 82108892A EP 0077926 B1 EP0077926 B1 EP 0077926B1
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- EP
- European Patent Office
- Prior art keywords
- nitriding
- salt bath
- bath
- selenium
- iron
- 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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- 150000003839 salts Chemical class 0.000 title claims abstract description 25
- 238000005121 nitriding Methods 0.000 title claims abstract description 22
- 238000000034 method Methods 0.000 title claims description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 16
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 14
- 239000010959 steel Substances 0.000 claims abstract description 14
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims abstract description 11
- 229910052711 selenium Inorganic materials 0.000 claims abstract description 11
- 239000011669 selenium Substances 0.000 claims abstract description 11
- 229910052742 iron Inorganic materials 0.000 claims abstract description 8
- XLJMAIOERFSOGZ-UHFFFAOYSA-M cyanate Chemical compound [O-]C#N XLJMAIOERFSOGZ-UHFFFAOYSA-M 0.000 claims abstract description 6
- 238000000576 coating method Methods 0.000 claims abstract description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- 229940065287 selenium compound Drugs 0.000 claims description 4
- 150000003343 selenium compounds Chemical class 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 3
- 229910052783 alkali metal Inorganic materials 0.000 claims 2
- -1 alkali metal cyanide Chemical class 0.000 claims 2
- 229910000990 Ni alloy Inorganic materials 0.000 claims 1
- 229910000288 alkali metal carbonate Inorganic materials 0.000 claims 1
- 150000008041 alkali metal carbonates Chemical class 0.000 claims 1
- 239000003513 alkali Substances 0.000 abstract description 9
- XFXPMWWXUTWYJX-UHFFFAOYSA-N Cyanide Chemical compound N#[C-] XFXPMWWXUTWYJX-UHFFFAOYSA-N 0.000 abstract description 6
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 abstract description 3
- 229940091258 selenium supplement Drugs 0.000 description 8
- 239000011888 foil Substances 0.000 description 5
- 230000015572 biosynthetic process Effects 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 230000004580 weight loss Effects 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000003749 cleanliness Effects 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- JPJALAQPGMAKDF-UHFFFAOYSA-N selenium dioxide Chemical compound O=[Se]=O JPJALAQPGMAKDF-UHFFFAOYSA-N 0.000 description 2
- 229910052714 tellurium Inorganic materials 0.000 description 2
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 2
- 230000004584 weight gain Effects 0.000 description 2
- 235000019786 weight gain Nutrition 0.000 description 2
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000005273 aeration Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 150000001913 cyanates Chemical class 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- BVTBRVFYZUCAKH-UHFFFAOYSA-L disodium selenite Chemical compound [Na+].[Na+].[O-][Se]([O-])=O BVTBRVFYZUCAKH-UHFFFAOYSA-L 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 150000002825 nitriles Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 230000001603 reducing effect Effects 0.000 description 1
- 150000003342 selenium Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229960001471 sodium selenite Drugs 0.000 description 1
- 235000015921 sodium selenite Nutrition 0.000 description 1
- 239000011781 sodium selenite Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
Definitions
- the invention relates to a method for suppressing harmful surface coverings in the salt bath nitriding on components made of steel and iron.
- Salt bath nitriding is used today worldwide to improve the wear properties and fatigue strength of components made of steel and iron.
- the salt bath process is also used more and more to improve the corrosion resistance of component surfaces made of steel and iron, whereby the development of a special salt bath for cooling the parts after nitriding (DE-A-2 934 113) has led to the corrosion properties inherent in the nitriding compound layer can still be significantly improved.
- a special salt bath for cooling the parts after nitriding (DE-A-2 934 113) has led to the corrosion properties inherent in the nitriding compound layer can still be significantly improved.
- This means that the process of salt bath nitriding is also of great importance for areas of application where the use of the rare and expensive chromium is otherwise required.
- Baths containing high levels of cyanide were originally used for the purpose of salt bath nitriding.
- the cyanate required for nitriding was generated by aeration, and these baths were also operated in titanium crucibles.
- cyanides in nitriding baths have a strongly reducing effect at temperatures between 550 ° C and 650 ° C, on the other hand cyanates tend to give off oxygen, the nitriding baths containing little cyanide tend to occasionally oxidize the nitriding compound layer so strongly that even after cooling and washing the components on the surface leaves a difficult to remove, dust-like coating.
- Such coverings are often not acceptable for further use of the nitrided component, since they are e.g. B. in hydraulic units in the oil flow and at sensitive points, for. B. on bearings, can lead to abrasive wear. In order to avoid such effects, time-consuming cleaning of the parts is often necessary.
- rust-red surface deposits can form if components which have been treated in such a nitriding bath are transferred to a cooling bath.
- a nitriding bath which is in an oxidizing state which is detrimental to the surface quality of the nitrided components is characterized, inter alia, in that a steel foil made of a steel with 0.05% carbon has a weight loss of the order of magnitude after a treatment time of 90 minutes to some 100 mg / dm 2 shows that treating the same steel foil under conditions that prevent the formation of deposits leads to a weight gain of up to approx. 70 mg / dm 2 . So far, however, it has not been possible to predict when a bathroom will produce good and unacceptable results in terms of surface cleanliness.
- CH-A-359 339 describes salt baths with which the wear resistance of the surface can be improved. These baths contain 20 to 30% alkali cyanide, 15 to 50% alkali cyanate, alkali chlorides, alkali carbonates and 0.1 to 5% selenium or tellurium. Selenium and tellurium penetrate into the surface layer and have a high resistance to wear. These baths cannot prevent the formation of harmful surface layers.
- This object was achieved in that for nitriding a salt bath of 0.01 to 3% cyanide in the form of alkali cyanide, 25-45% cyanate in the form of alkali cyanate, 0.5 to 100 ppm selenium in the form of selenium compounds and / or elemental Selenium, balance alkali carbonate, is used.
- the selenium or selenium compounds can be added directly to the liquid salt bath, or salts are used to melt the bath, to which appropriate amounts of selenium have already been added during their production.
- the bath temperature is preferably between 550 and 650 ° C.
- a salt bath crucible that is as free of iron as possible.
- Crucibles made from titanium or from virtually iron-free chromium-nickel alloys have proven successful, although they can also contain up to 10% by weight of iron.
- the contents of selenium or selenium compounds according to the invention permanently prevent the formation of deposits on the surface of the nitrided components in the nitriding salt baths.
- An environmentally friendly, low-cyanide nitriding bath is operated in an electrically heated furnace in a titanium crucible with the dimensions 35/70 cm.
- the bath had the following composition: 38% CNO-, 0.5% CN-, about 15% carbonate, balance sodium and potassium.
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- 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)
- Chemical Treatment Of Metals (AREA)
- Artificial Fish Reefs (AREA)
- Cosmetics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Removal Of Specific Substances (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Electroplating And Plating Baths Therefor (AREA)
- Compounds Of Iron (AREA)
- Polysaccharides And Polysaccharide Derivatives (AREA)
- Automobile Manufacture Line, Endless Track Vehicle, Trailer (AREA)
- Catalysts (AREA)
- Fertilizers (AREA)
- Processing Of Solid Wastes (AREA)
- Detergent Compositions (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Treatment Of Steel In Its Molten State (AREA)
- Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
- Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
- Absorbent Articles And Supports Therefor (AREA)
- Polyesters Or Polycarbonates (AREA)
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- Coating With Molten Metal (AREA)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Unterdrückung von schädlichen Oberflächenbelägen beim Salzbad nitrieren auf Bauteilen aus Stahl und Eisen.The invention relates to a method for suppressing harmful surface coverings in the salt bath nitriding on components made of steel and iron.
Das Salzbadnitrieren wird heute weltweit angewandt, um die Verschleißeigenschaft und die Dauerfestigkeit von Bauteilen aus Stahl und Eisen zu verbessern. Auch zur Verbesserung der Korrosionsbeständigkeit von Bauteiloberflächen aus Stahl und Eisen findet das Salzbadverfahren mehr und mehr Anwendungen, wobei die Entwicklung eines speziellen Salzbades zum Abkühlen derTeile nach dem Nitrieren (DE-A-2 934 113) dazu geführt hat, daß die der Nitrierverbindungsschicht eigenen Korrosionseigenschaften noch deutlich verbessert werden können. Damit gewinnt das Verfahren der Salzbadnitrierung große Bedeutung auch für Anwendungsgebiete, wo ansonsten die Verwendung des selten und teuren Chroms erforderlich ist.Salt bath nitriding is used today worldwide to improve the wear properties and fatigue strength of components made of steel and iron. The salt bath process is also used more and more to improve the corrosion resistance of component surfaces made of steel and iron, whereby the development of a special salt bath for cooling the parts after nitriding (DE-A-2 934 113) has led to the corrosion properties inherent in the nitriding compound layer can still be significantly improved. This means that the process of salt bath nitriding is also of great importance for areas of application where the use of the rare and expensive chromium is otherwise required.
Ursprünglich wurden zum Zwecke des Salzbadnitrierens Bäder verwendet, die hohe Anteile an Cyanid enthielten. Das zum Nitrieren notwendige Cyanat wurde durch Belüftung erzeugt, außerdem wurden diese Bäder in Titantiegeln betrieben.Baths containing high levels of cyanide were originally used for the purpose of salt bath nitriding. The cyanate required for nitriding was generated by aeration, and these baths were also operated in titanium crucibles.
Die steigenden Anforderungen an möglichst niedrige Umweltbelastung haben dazu geführt, daß die hochcyanidhaltigen Salzbäder durch praktisch cyanidfreie Bäder ersetzt worden sind, bei denen zudem das Regenerieren der Bäder mit Hilfe eines organischen Stoffes erfolgt, womit die Bildung von giftigen Altsalzen vermieden werden kann (DE-A-2 310 815).The increasing demands for the lowest possible environmental impact have led to the fact that the high-cyanide salt baths have been replaced by practically cyanide-free baths, in which the baths are also regenerated with the help of an organic substance, with which the formation of toxic old salts can be avoided (DE-A -2 310 815).
Da Cyanide in Nitrierbädern bei Temperaturen zwischen 550° C und 650° C stark reduzierend wirken, Cyanate andererseits eher dazu tendieren, Sauerstoff abzugeben, zeigen die nur wenig Cyanid enthaltenden Nitrierbäder die Tendenz, gelegentlich die Nitrierverbindungsschicht derart stark zu oxidieren, daß auch nach dem Abkühlen und Waschen der Bauteile auf der Oberfläche ein schwer zu entfernender, staubförmiger Belag zurückbleibt. Oft sind solche Beläge für die Weiterverwendung des nitrierten Bauteiles nicht akteptabel, da sie z. B. bei Hydraulikaggregaten in den Ölstrom gelangen und an empfindlichen Stellen, z. B. an Lagern, zu abrasivem Verschleiß führen können. Um derartige Effekte zu vermeiden, ist oft ein zeitaufwendiges Reinigen der Teile notwendig.Since cyanides in nitriding baths have a strongly reducing effect at temperatures between 550 ° C and 650 ° C, on the other hand cyanates tend to give off oxygen, the nitriding baths containing little cyanide tend to occasionally oxidize the nitriding compound layer so strongly that even after cooling and washing the components on the surface leaves a difficult to remove, dust-like coating. Such coverings are often not acceptable for further use of the nitrided component, since they are e.g. B. in hydraulic units in the oil flow and at sensitive points, for. B. on bearings, can lead to abrasive wear. In order to avoid such effects, time-consuming cleaning of the parts is often necessary.
Außerdem kann es zur Bildung von rostroten Oberflächenbelägen kommen, wenn Bauteile, die in einem derartigen Nitrierbad behandelt wurden, in ein Abkühlbad übergeführt werden.In addition, rust-red surface deposits can form if components which have been treated in such a nitriding bath are transferred to a cooling bath.
Ein Nitrierbad, das sich in einem für die Oberflächenqualität der nitrierten Bauteile schädlichen, oxidierenden Zustand befindet, ist u. a., dadurch charakterisiert, daß eine Stahlfolie aus einem Stahl mit 0,05% Kohlenstoff nach einer Behandlungsdauer von 90 Minuten einen Gewichtsverlust in der Größenordnung von bis zu einigen 100 mg/dm2 zeigt, die Behandlung der gleichen Stahlfolie unter Bedingungen, die die Bildung von Belägen verhindert, zu einer Gewichtszunahme bis zu ca. 70 mg/dm2 führt. Es ist bisher jedoch nicht möglich vorauszubestimmen, wann ein Bad gute und wann es nicht akzeptable Ergebnisse im Hinblick auf Oberflächensauberkeit hervorruft.A nitriding bath which is in an oxidizing state which is detrimental to the surface quality of the nitrided components is characterized, inter alia, in that a steel foil made of a steel with 0.05% carbon has a weight loss of the order of magnitude after a treatment time of 90 minutes to some 100 mg / dm 2 shows that treating the same steel foil under conditions that prevent the formation of deposits leads to a weight gain of up to approx. 70 mg / dm 2 . So far, however, it has not been possible to predict when a bathroom will produce good and unacceptable results in terms of surface cleanliness.
Solche Salzbäder mußten bisher auf umständlicher und kostenintensiver Weise durch Hochheizen und Entschlammen soweit regeneriert werden, daß sie wieder gute Ergebnisse in bezug auf die Oberflächensauberkeit der nitrierten Bauteile aufwiesen. Diese günstigen Eigenschaften zeigten die so regenerierten Salzbäder jedoch nur relativ kurze Zeit und mußten dann entweder erneut regeneriert oder neu angesetzt werden.Until now, such salt baths had to be regenerated in a cumbersome and cost-intensive manner by heating and desludging to such an extent that they again had good results with regard to the surface cleanliness of the nitrided components. However, the salt baths regenerated in this way showed these favorable properties only for a relatively short time and then either had to be regenerated again or prepared again.
Die CH-A-359 339 beschreibt Salzbäder, mit denen sich die Verschleißfestigkeit der Oberfläche verbessern läßt. Diese Bäder enthalten 20 bis 30% Alkalicyanid, 15 bis 50% Alkalicyanat, Alkalichloride, Alkalicarbonate und 0,1 bis 5% Selen oder Tellur. Selen und Tellur dringen dabei in die Oberflächenschicht ein und bewirken eine hohe Widerstandsfähigkeit gegen Verschleiß. Die Bildung von schädlichen Oberflächenschichten können diese Bäder aber nicht verhindern.CH-A-359 339 describes salt baths with which the wear resistance of the surface can be improved. These baths contain 20 to 30% alkali cyanide, 15 to 50% alkali cyanate, alkali chlorides, alkali carbonates and 0.1 to 5% selenium or tellurium. Selenium and tellurium penetrate into the surface layer and have a high resistance to wear. These baths cannot prevent the formation of harmful surface layers.
Es war daher Aufgabe der vorliegenden Erfindung, ein Verfahren zur Unterdrückung von schädlichen Oberflächenschichten beim Salzbadnitrieren von Bauteilen aus Stahl und Eisen zu schaffen.It was therefore an object of the present invention to provide a method for suppressing harmful surface layers during salt bath nitriding of components made of steel and iron.
Diese Aufgabe wurde erfindungsgemäß dadurch gelöst, daß zum Nitrieren ein Salzbad aus 0,01 bis 3% Cyanid in Form von Alkalicyanid, 25-45% Cyanat in Form von Alkalicyanat, 0,5 bis 100 ppm Selen in Form von Selenverbindungen und/oder elementarem Selen, Rest Alkalicarbonat, verwendet wird.This object was achieved in that for nitriding a salt bath of 0.01 to 3% cyanide in the form of alkali cyanide, 25-45% cyanate in the form of alkali cyanate, 0.5 to 100 ppm selenium in the form of selenium compounds and / or elemental Selenium, balance alkali carbonate, is used.
Das Selen bzw. die Selenverbindungen können dabei dem flüssigen Salzbad direkt zugesetzt werden, oder man verwendet beim Einschmelzen des Bades Salze, denen bereits während ihrer Herstellung entsprechende Mengen Selen beigegeben wurden.The selenium or selenium compounds can be added directly to the liquid salt bath, or salts are used to melt the bath, to which appropriate amounts of selenium have already been added during their production.
Vorzugsweise liegt die Badtemperatur zwischen 550 und 650° C.The bath temperature is preferably between 550 and 650 ° C.
Außerdem verwendet man vorteilhafterweise einen Salzbadtiegel, der möglichst eisenfrei ist. Bewährt haben sich dabei Tiegel aus Titan oder aus nahezu eisenfreien Chrom-Nickel-Legierungen, die allerdings auch bis zu 10 Gew.-% Eisen enthalten können.In addition, it is advantageous to use a salt bath crucible that is as free of iron as possible. Crucibles made from titanium or from virtually iron-free chromium-nickel alloys have proven successful, although they can also contain up to 10% by weight of iron.
Die erfindungsgemäßen Gehalte an Selen oder Selenverbindungen verhindern in den Nitriersalzbädern nachhaltig die Bildung von Belägen auf der Oberfläche der nitrierten Bauteile.The contents of selenium or selenium compounds according to the invention permanently prevent the formation of deposits on the surface of the nitrided components in the nitriding salt baths.
Folgende Beispiele sollen das erfindungsgemäße Verfahren näher erläutern:The following examples are intended to explain the process according to the invention in more detail:
Ein umweltfreundliches, cyanidarmes Nitrierbad wird in einem elektrisch beheizten Ofen in einem Titantiegel mit den Abmessungen 35/ 70 cm betrieben. Das Bad hatte folgende Zusammensetzung: 38% CNO-, 0,5% CN-, etwa 15% Carbonat, Rest Natrium und Kalium.An environmentally friendly, low-cyanide nitriding bath is operated in an electrically heated furnace in a titanium crucible with the dimensions 35/70 cm. The bath had the following composition: 38% CNO-, 0.5% CN-, about 15% carbonate, balance sodium and potassium.
Eine Stahlfolie mit einem Kohlenstoffgehalt von 0,05%, 90 Minuten in diesem Bad behandelt und in Wasser abgekühlt, zeigte einen Gewichtsverlust von 185 mg/dm2. Zu gleicher Zeit behandelte Bauteile aus Stahl wiesen an der Oberfläche einen schwarzen abwischbaren Belag auf.A steel foil with a carbon content of 0.05%, treated in this bath for 90 minutes and cooled in water, showed a weight loss of 185 mg / dm 2. Steel components treated at the same time had a black wipeable coating on the surface.
Dem Bad wurden dann mit Hilfe eines Löffels ca. 1,44 g SeOz zugesetzt (d. H. bei 85 kg Salzinhalt entsprechend 12 ppm).About 1.44 g of SeOz was then added to the bath using a spoon (i.e. with 85 kg salt content corresponding to 12 ppm).
Eine nach dem Selenzusatz wie oben durchgeführte Probe ergab bei der Folie eine Gewichtszunahme um 51 mg/dm2. Gleichzeitig mitbehandelte Bauteile aus Stahl hatten eine hellgraue, völlig belagfreie Oberfläche. Die günstige Wirkung dieses Selenzusatzes hält für viele Wochen an.A sample carried out after the selenium addition as above resulted in a weight gain of 51 mg / dm 2 for the film . At the same time, components made of steel had a light gray, completely deposit-free surface. The beneficial effects of this selenium additive last for many weeks.
Einem Nitriersalzbad gemäß Beispiel 1, welches sich in einem Zustand befindet, der durch einen Gewichtsverlust der Stahlfolie gekennzeichnet ist, werden 1,86 g Natriumselenit zugesetzt. Die daraufhin behandelten Folien zeigen eine Gewichtszunahme, die behandelten Bauteile weisen ebenfalls eine saubere Oberfläche auf.1.86 g of sodium selenite are added to a nitriding salt bath according to Example 1, which is in a state which is characterized by a loss in weight of the steel foil. The films subsequently treated show an increase in weight, and the treated components also have a clean surface.
Einer Produktionscharge von 1 t des obengenannten Salzes werden 14,4 g Selendioxid zugesetzt. Bei der Verwendung eines solchen Salzes im praktischen Betrieb kommt es in keinem Falle mehr zum Auftreten von Badzuständen, die durch Gewichtsverluste an einer Stahlfolie gekennzeichnet sind.14.4 g of selenium dioxide are added to a production batch of 1 t of the salt mentioned above. When such a salt is used in practical operation, bath conditions characterized by weight losses on a steel foil no longer occur.
Claims (3)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19813142318 DE3142318A1 (en) | 1981-10-24 | 1981-10-24 | SALT BATH FOR NITRATING IRON MATERIALS |
| DE3142318 | 1981-10-24 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0077926A1 EP0077926A1 (en) | 1983-05-04 |
| EP0077926B1 true EP0077926B1 (en) | 1985-12-04 |
Family
ID=6144805
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP82108892A Expired EP0077926B1 (en) | 1981-10-24 | 1982-09-25 | Process to suppress surface deposits during salt bath nitriding of structural parts |
Country Status (19)
| Country | Link |
|---|---|
| US (1) | US4492604A (en) |
| EP (1) | EP0077926B1 (en) |
| JP (1) | JPS5877567A (en) |
| AT (1) | ATE16821T1 (en) |
| AU (1) | AU555316B2 (en) |
| BR (1) | BR8206180A (en) |
| CA (1) | CA1208527A (en) |
| DE (2) | DE3142318A1 (en) |
| DK (1) | DK156491C (en) |
| EG (1) | EG15636A (en) |
| ES (1) | ES8401531A1 (en) |
| FI (1) | FI70053C (en) |
| HU (1) | HU188217B (en) |
| IN (1) | IN155704B (en) |
| PT (1) | PT75706B (en) |
| RO (1) | RO85594B (en) |
| TR (1) | TR21943A (en) |
| YU (1) | YU43102B (en) |
| ZA (1) | ZA826635B (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3403463A1 (en) * | 1984-02-01 | 1985-08-08 | Kraftwerk Union AG, 4330 Mülheim | MATERIAL MATERIALS FOR HIGH-LOADED MACHINE ELEMENTS |
| US5707460A (en) * | 1995-07-11 | 1998-01-13 | Porter-Cable Corporation | Method of producing parts having improved wear, fatigue and corrosion resistance from medium alloy, low carbon steel and parts obtained therefrom |
| DE60042630D1 (en) * | 1999-05-28 | 2009-09-10 | Honda Motor Co Ltd | Process for producing laminated rings and molten salt composition for use in this process |
| US6645566B2 (en) * | 1999-06-01 | 2003-11-11 | Jong Ho Ko | Process for heat treatment nitriding in the presence of titanium and products produced thereby |
| JP2003502085A (en) * | 1999-06-14 | 2003-01-21 | コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ | MRI apparatus having anti-jamming supply leads for electrically connected equipment |
| US6746546B2 (en) * | 2001-11-02 | 2004-06-08 | Kolene Corporation | Low temperature nitriding salt and method of use |
| KR100513563B1 (en) * | 2002-05-21 | 2005-09-09 | 고종호 | A process for Heat treatment by Nitriding of base metals in the presence of Titanium |
| US20070013279A1 (en) * | 2004-03-23 | 2007-01-18 | Macmillan Michael | Bathroom cabinet and method of installation |
| JP4943018B2 (en) * | 2006-02-23 | 2012-05-30 | ヤマハリビングテック株式会社 | Bathroom mirror and bathroom mirror mounting structure |
| US7438769B2 (en) * | 2006-04-18 | 2008-10-21 | Philos Jongho Ko | Process for diffusing titanium and nitride into a material having a coating thereon |
| US7732014B2 (en) | 2006-04-18 | 2010-06-08 | Philos Jongho Ko | Process for diffusing titanium and nitride into a material having a generally compact, granular microstructure |
| FR2972459B1 (en) | 2011-03-11 | 2013-04-12 | Hydromecanique & Frottement | FOUNDED SALT BATHS FOR NITRIDING STEEL MECHANICAL PARTS, AND METHOD FOR IMPLEMENTING THE SAME |
| CN103122446A (en) * | 2013-02-02 | 2013-05-29 | 大连经济技术开发区圣洁真空技术开发有限公司 | Quantitative titanium nitriding carbonitriding technique |
| CN103882370A (en) * | 2014-03-24 | 2014-06-25 | 合肥美桥汽车传动及底盘系统有限公司 | 42CrMo or 40Cr steering knuckle nitrocarburizing treatment process |
Family Cites Families (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR359339A (en) * | 1904-11-15 | 1906-03-21 | Siemens Et Halske Aktien Ges | Method of manufacturing an incandescent body for electric light by forming a metal deposit on a metal core |
| US2875095A (en) * | 1956-10-06 | 1959-02-24 | Gold Und Silber Scheldeanstalt | Method of producing surface layers resistant to wear |
| DE1052424B (en) * | 1957-06-26 | 1959-03-12 | Degussa | Process for carburizing and carbonitriding of iron and steel |
| DE1237872B (en) * | 1961-12-07 | 1967-03-30 | Degussa | Metal lining for containers for salt bath nitriding of ferrous metals |
| FR86012E (en) * | 1963-12-11 | 1965-11-26 | Berliet Automobiles | friction elements particularly resistant to abrasion wear |
| US3507757A (en) * | 1966-04-04 | 1970-04-21 | Jacques Jean Caubet | Treatment of metal surfaces |
| US4019928A (en) * | 1973-03-05 | 1977-04-26 | Duetsche Gold- Und Silber-Scheideanstalt Vormals Roessler | Process for nitriding iron and steel in salt baths regenerated with triazine polymers |
| DE2514398C2 (en) * | 1975-04-02 | 1984-04-05 | Degussa Ag, 6000 Frankfurt | Salt bath to quench bath nitrided components |
| DE2934113C2 (en) * | 1979-08-23 | 1985-05-09 | Degussa Ag, 6000 Frankfurt | Process for increasing the corrosion resistance of nitrided components made of ferrous materials |
-
1981
- 1981-10-24 DE DE19813142318 patent/DE3142318A1/en not_active Withdrawn
-
1982
- 1982-09-08 FI FI823106A patent/FI70053C/en not_active IP Right Cessation
- 1982-09-09 ZA ZA826635A patent/ZA826635B/en unknown
- 1982-09-15 AU AU88411/82A patent/AU555316B2/en not_active Ceased
- 1982-09-25 DE DE8282108892T patent/DE3267827D1/en not_active Expired
- 1982-09-25 EP EP82108892A patent/EP0077926B1/en not_active Expired
- 1982-09-25 AT AT82108892T patent/ATE16821T1/en not_active IP Right Cessation
- 1982-10-06 TR TR21943A patent/TR21943A/en unknown
- 1982-10-11 ES ES516409A patent/ES8401531A1/en not_active Expired
- 1982-10-18 JP JP57181494A patent/JPS5877567A/en active Granted
- 1982-10-20 PT PT75706A patent/PT75706B/en not_active IP Right Cessation
- 1982-10-20 US US06/435,401 patent/US4492604A/en not_active Expired - Fee Related
- 1982-10-21 YU YU2374/82A patent/YU43102B/en unknown
- 1982-10-22 DK DK470282A patent/DK156491C/en active
- 1982-10-22 IN IN1258/CAL/82A patent/IN155704B/en unknown
- 1982-10-22 HU HU823385A patent/HU188217B/en not_active IP Right Cessation
- 1982-10-22 CA CA000414031A patent/CA1208527A/en not_active Expired
- 1982-10-22 BR BR8206180A patent/BR8206180A/en not_active IP Right Cessation
- 1982-10-22 RO RO108854A patent/RO85594B/en unknown
- 1982-10-23 EG EG627/82A patent/EG15636A/en active
Also Published As
| Publication number | Publication date |
|---|---|
| YU237482A (en) | 1985-03-20 |
| YU43102B (en) | 1989-02-28 |
| JPH0217622B2 (en) | 1990-04-23 |
| FI823106A0 (en) | 1982-09-08 |
| DE3267827D1 (en) | 1986-01-16 |
| ZA826635B (en) | 1983-07-27 |
| RO85594B (en) | 1985-03-30 |
| DK470282A (en) | 1983-04-25 |
| HU188217B (en) | 1986-03-28 |
| IN155704B (en) | 1985-02-23 |
| RO85594A (en) | 1985-03-15 |
| CA1208527A (en) | 1986-07-29 |
| FI823106L (en) | 1983-04-25 |
| TR21943A (en) | 1985-11-28 |
| BR8206180A (en) | 1983-09-20 |
| DK156491B (en) | 1989-08-28 |
| PT75706B (en) | 1985-06-28 |
| US4492604A (en) | 1985-01-08 |
| JPS5877567A (en) | 1983-05-10 |
| DE3142318A1 (en) | 1983-05-05 |
| ATE16821T1 (en) | 1985-12-15 |
| EG15636A (en) | 1989-01-30 |
| DK156491C (en) | 1990-02-12 |
| EP0077926A1 (en) | 1983-05-04 |
| ES516409A0 (en) | 1983-12-01 |
| AU555316B2 (en) | 1986-09-18 |
| PT75706A (en) | 1982-11-01 |
| AU8841182A (en) | 1983-04-28 |
| FI70053B (en) | 1986-01-31 |
| FI70053C (en) | 1986-09-12 |
| ES8401531A1 (en) | 1983-12-01 |
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