EP0067098B1 - Verfahren zur Ionisierung eines Werkstückes aus Stahl, das zuvor plastisch verformt wurde - Google Patents

Verfahren zur Ionisierung eines Werkstückes aus Stahl, das zuvor plastisch verformt wurde Download PDF

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Publication number
EP0067098B1
EP0067098B1 EP82400928A EP82400928A EP0067098B1 EP 0067098 B1 EP0067098 B1 EP 0067098B1 EP 82400928 A EP82400928 A EP 82400928A EP 82400928 A EP82400928 A EP 82400928A EP 0067098 B1 EP0067098 B1 EP 0067098B1
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EP
European Patent Office
Prior art keywords
nitrogen
pascal
sequence
nitriding
temperature
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
EP82400928A
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English (en)
French (fr)
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EP0067098A1 (de
Inventor
Robert Leveque
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.)
Creusot Loire SA
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Creusot Loire SA
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Publication date
Application filed by Creusot Loire SA filed Critical Creusot Loire SA
Priority to AT82400928T priority Critical patent/ATE16293T1/de
Publication of EP0067098A1 publication Critical patent/EP0067098A1/de
Application granted granted Critical
Publication of EP0067098B1 publication Critical patent/EP0067098B1/de
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    • 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
    • C23C8/02—Pretreatment of the material to be coated
    • 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
    • C23C8/06—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 gases
    • C23C8/36—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 gases using ionised gases, e.g. ionitriding
    • C23C8/38—Treatment of ferrous surfaces

Definitions

  • the present invention relates to ion nitriding of steels.
  • the combination layer because of the appearance of cracks at the limit of the two categories of nitrides, and the rapid spalling of the most superficial compounds
  • the diffusion layer because of carbonitride precipitation, poorly resistant to the mechanical and thermal stresses to which the two nitrided layers are subjected.
  • the nature and size of the diffusion zone have effects on the greater or lesser increase in the set of resistance properties of the part, in particular on its dynamic resistance to alternating forces, and, in. a smaller measurement, on its wear resistance and on its sliding properties.
  • this base material under the diffusion zone is the base material, not reached by the diffusion of nitrogen, and therefore which must remain unchanged by the nitriding treatment.
  • this base material must of itself have as high a resistance as possible, which is not likely to be compromised by the thermal conditions of nitriding.
  • this base material is then capable of providing sufficient mechanical support to all of the two relatively thin nitriding layers, so that the total resistance of the part is satisfactory.
  • Ion nitriding of steel parts uses an electrical discharge created by a potential difference between 400 and 700 volts between the part to be treated, constituting the cathode, and the wall of the reactor. constituting the anode, in an enclosure placed under reduced pressure, generally between 100 and 1000 Pascal, of a gas constituted by a mixture of nitrogen and hydrogen, which may contain between 1% and 35% of nitrogen in volume depending on the case, possibly with a little gaseous hydrocarbons, at temperatures between 430 ° and 600 ° C.
  • the parts thus treated by ionic nitriding are characterized in that they have an outer combination layer free of pores and of single-phase composition, with a thickness of 10 micrometers at most, and a diffusion zone free to a large extent of networks. and nitride lines.
  • One of the essential advantages of ionic nitriding is to achieve independence between the treatment temperature, which is a function of the parameters of the electrical discharge (voltage, intensity, gas pressure), and the activity of the reaction medium, which depends on the mixture. gas used.
  • the aim of the present invention is to take advantage of the beneficial effect of prior work hardening on the growth kinetics of the nitrided layers, while avoiding any risk of excessive brittleness, and yet without practicing any special stress relieving treatment.
  • the duration of the first sequence of ionic nitriding and the duration of the second sequence are all the longer as the steel to be treated is no longer loaded with alloying elements. This is due to the fact that, in p1 steels more loaded with alloying elements, such as stainless steels or refractory steels, the restoration of the structure after work hardening is slower.
  • the part having first undergone a final work hardening rate of between 10% and 40%, for example close to 30% by cold hammering, is then subjected to a first sequence of ionic nitriding for a period of between 2 and 4 hours, at a temperature between 490 ° and 510 ° C, in a gaseous mixture of nitrogen and hydrogen such that the partial pressure of nitrogen is between 10 and 15 Pascal, the total gas pressure being included between 200 and 650 Pascal.
  • the part is subjected to a second sequence of ionic nitriding for a period of between 25 and 40 hours, at a temperature between 510 ° and 560 ° C, in a gaseous mixture of nitrogen and hydrogen such as pressure partial nitrogen is of the order of 60 Pascal, the total gas pressure remaining between 200 and 650 Pascal.
  • a gaseous mixture of nitrogen and hydrogen such as pressure partial nitrogen is of the order of 60 Pascal, the total gas pressure remaining between 200 and 650 Pascal.
  • the part, having undergone the same work hardening as previously, is then subjected to a first nitriding sequence for a period of between 6 and 10 hours, at a temperature between 500 ° and 520 ° C, in a gaseous mixture of nitrogen and hydrogen such as the partial pressure of nitrogen is between 30 and 35 Pascal, the total gas pressure being between 200 and 650 Pascal.
  • the part is subjected to a second sequence of ionic nitriding, for a period of between 40 and 70 hours, at a temperature of between 500 and 580 ° C., in a mixture of nitrogen and hydrogen such as partial pressure nitrogen is between 60 and 80 Pascal, and preferably close to 70 Pascal, the total gas pressure remaining between 200 and 650 Pascal.
  • a second sequence of ionic nitriding for a period of between 40 and 70 hours, at a temperature of between 500 and 580 ° C., in a mixture of nitrogen and hydrogen such as partial pressure nitrogen is between 60 and 80 Pascal, and preferably close to 70 Pascal, the total gas pressure remaining between 200 and 650 Pascal.
  • the gaseous mixture used always consists of nitrogen and hydrogen
  • the relative proportions of these two gases, at least in the first sequence of ionic nitriding must be regulated according to the composition of the steel, and more particularly to its contents in elements of alloys avid of nitrogen, such as: chromium, vanadium, titanium and aluminum.
  • elements of alloys avid of nitrogen such as: chromium, vanadium, titanium and aluminum.
  • the length of the first sequence is very important.
  • the surface decarburization which is caused by this phase of the treatment can lead, if it is continued for too long, to modifications in the mechanical properties of the nitrided layers.
  • the penetration of nitrogen into the steel is facilitated by the reduction in the quantity of carbides, and this can result in a significant reduction in the surface hardness, with, as a consequence, a reduction in the following properties: resistance to 'sinking, wear, and mechanical or thermal fatigue.
  • This first sequence is then followed by a second sequence, in which the activity of the reaction medium is modified as a function of the thickness of the combination layer which it is desired to obtain at the surface.
  • the temperature and the holding time must be adjusted taking into account the beneficial influence of the preliminary work hardening on the growth kinetics of the nitrided layers.
  • This phenomenon controlled by the diffusion of nitrogen in the treated part, can be visualized by a graph representing the evolution of the e / VE ratio (e being the thickness of the layers in micrometers and t being the holding time in hours ) as a function of the inverse of the absolute temperature.
  • This representation makes it possible to determine in the second sequence of the treatment, the holding time necessary to produce a nitrided layer of given thickness at a given temperature, which characterizes the growth kinetics.
  • the gain on the total treatment time of the second part (according to the invention) compared to the first is significant, and that it is understood between 10% and 50% depending on the case.
  • the first tube then undergoes stress relieving at 500 ° C for three hours in a conventional oven with controlled atmosphere.
  • the constraints are then lowered to the following values:
  • This first tube then undergoes conventional ionic nitriding, under the conditions indicated above.
  • the second tube undergoes ionic nitriding in two successive sequences according to the invention, under the conditions indicated above.
  • the kinetics of growth of the layers by this ionic nitriding according to the invention is represented by curve 2 of FIG. 1.
  • FIG. 2 Another way of considering the previous comparison is shown in FIG. 2, on which we have plotted on the abscissa, on a linear scale, the ion nitriding temperatures (that of the second sequence in the case of the invention) and on the ordinate , on a logarithmic scale, the nitriding times, by representing by two bundles of lines the nitriding depths reached on the one hand for the first tube (straight lines in solid lines) and on the other hand for the second tube, according to the invention (straight dashed lines, for respective values of 200, 300, 400, 500 and 600 micrometers.
  • a second sequence lasting between 20 and 40 hours, depending on the nature of the steel to be treated, carried out at a temperature t2 between 530 ° and 550 ° C, in a gaseous mixture of nitrogen and hydrogen such as the partial pressure of nitrogen p2 is between 20 and 60 Pascal and is greater than p1.

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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)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
  • Physical Vapour Deposition (AREA)
  • Catalysts (AREA)
  • Laminated Bodies (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Heat Treatment Of Steel (AREA)
  • Preparation Of Compounds By Using Micro-Organisms (AREA)
  • Forging (AREA)
  • Materials For Medical Uses (AREA)
  • Investigating And Analyzing Materials By Characteristic Methods (AREA)

Claims (3)

1. Verfahren zur lonennitrierung von Stahlwerkstücken aller Arten; das aus der Abfolge der folgenden vier Phasen besteht :
a) ein vorheriger Kaltverformungsvorgang des Werkstücks, dessen Endverformungsgrad im Bereich von 10% bis 40 % liegt ;
b) eine erste lonennitrierungsfolge einer Dauer im Bereich von 6 bis 10 Stunden, die bei einer Temperatur t1 im Bereich zwischen 500 und 520 °C in einem solchen Gasgemisch von Stickstoff und Wasserstoff durchgeführt wird, daß der Stickstoffpartialdruck p1 im Bereich von 10 bis 35 Pascal liegt und daß der Gesamtgasdruck im Bereich von 200 bis 650 Pascal liegt ;
c) eine zweite lonennitrierungsfolge einer Dauer im Bereich von 40 bis 70 Stunden, die bei einer Temperatur t2 im Bereich zwischen 500 und 580 °C sowie mindestens 10° und höchstens 50 °C über t1 in einem solchen Gasgemisch von Stickstoff und Wasserstoff durchgeführt wird, daß der Stickstoffpartialdruck p2 im Bereich von 60 bis 80 Pascal liegt und daß der Gesamtgasdruck im Bereich von 200 bis 650 Pascal liegt ;
d) eine Schlußabkühlung im Vakuum.
2. Verfahren zur lonennitrierung nach Anspruch 1, dadurch gekennzeichnet, daß der Endgrad vorheriger Kaltverformung des zu behandelnden Werkstücks in der Größenordnung von 30 % ist.
3. Verfahren zur lonennitrierung nach irgendeinem der Ansprüche 1 und 2, dadurch gekennzeichnet, daß die Dauer der ersten lonennitrierungsfolge und die der zweiten Folge umso länger sind, je mehr der zu behandelnde Stahl mit Legierungselementen versetzt ist.
EP82400928A 1981-05-21 1982-05-19 Verfahren zur Ionisierung eines Werkstückes aus Stahl, das zuvor plastisch verformt wurde Expired EP0067098B1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AT82400928T ATE16293T1 (de) 1981-05-21 1982-05-19 Verfahren zur ionisierung eines werkstueckes aus stahl, das zuvor plastisch verformt wurde.

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8110129 1981-05-21
FR8110129A FR2506339A1 (fr) 1981-05-21 1981-05-21 Methode de nitruration ionique d'une piece en acier deformee plastiquement au prealable

Publications (2)

Publication Number Publication Date
EP0067098A1 EP0067098A1 (de) 1982-12-15
EP0067098B1 true EP0067098B1 (de) 1985-10-30

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EP82400928A Expired EP0067098B1 (de) 1981-05-21 1982-05-19 Verfahren zur Ionisierung eines Werkstückes aus Stahl, das zuvor plastisch verformt wurde

Country Status (9)

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EP (1) EP0067098B1 (de)
AT (1) ATE16293T1 (de)
DE (1) DE3267120D1 (de)
DK (1) DK157691C (de)
ES (1) ES512331A0 (de)
FR (1) FR2506339A1 (de)
GR (1) GR75839B (de)
PT (1) PT74775B (de)
ZA (1) ZA823472B (de)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8619436D0 (en) * 1986-08-08 1986-09-17 Verdict Ion Technology Ltd Tooling
DE4429943C1 (de) * 1994-08-24 1996-02-22 Dornier Gmbh Lindauer Verfahren zur Standzeiterhöhung von Webblattlamellen
DE102006025008B4 (de) 2006-05-30 2022-09-15 Schaeffler Technologies AG & Co. KG Verfahren zum Härten von Laufflächen von Wälzlagerkomponenten
DE102008060161B4 (de) * 2008-12-02 2012-07-19 Benteler Automobiltechnik Gmbh Verfahren zur Herstellung einer Fahrwerkskomponente mit erhöhter Dauerfestigkeit und Fahrwerkskomponente
LU92514B1 (fr) * 2014-08-08 2016-02-09 Plasma Metal S A Procede de traitement de surface d'une piece en acier inoxydable
CN105695922A (zh) * 2014-11-25 2016-06-22 上海新力动力设备研究所 30Cr3SiNiMoVA钢的表面辉光离子渗氮方法

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR86012E (fr) * 1963-12-11 1965-11-26 Berliet Automobiles éléments de frottement résistant particulièrement à l'usure par abrasion
JPS5458637A (en) * 1977-10-20 1979-05-11 Kawasaki Heavy Ind Ltd Ion nitriding method
JPS5458636A (en) * 1977-10-20 1979-05-11 Kawasaki Heavy Ind Ltd Ion nitriding method
JPS5514839A (en) * 1978-07-14 1980-02-01 Kawasaki Heavy Ind Ltd Treating method for ion nitriding
FR2446326A1 (fr) * 1979-01-10 1980-08-08 Creusot Loire Perfectionnement a la nitruration ionique des corps creux allonges, en aciers

Also Published As

Publication number Publication date
EP0067098A1 (de) 1982-12-15
PT74775A (fr) 1982-05-01
DK157691B (da) 1990-02-05
GR75839B (de) 1984-08-02
ATE16293T1 (de) 1985-11-15
ES8304613A1 (es) 1983-03-01
DK228982A (da) 1982-11-22
DK157691C (da) 1990-07-02
ZA823472B (en) 1983-03-30
PT74775B (fr) 1983-11-08
FR2506339A1 (fr) 1982-11-26
DE3267120D1 (en) 1985-12-05
FR2506339B1 (de) 1983-12-23
ES512331A0 (es) 1983-03-01

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