WO2001014611A1 - Method for nitro-carburization of metal workpieces - Google Patents
Method for nitro-carburization of metal workpieces Download PDFInfo
- Publication number
- WO2001014611A1 WO2001014611A1 PCT/EP2000/007576 EP0007576W WO0114611A1 WO 2001014611 A1 WO2001014611 A1 WO 2001014611A1 EP 0007576 W EP0007576 W EP 0007576W WO 0114611 A1 WO0114611 A1 WO 0114611A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- treatment
- gas
- carbon
- temperature
- carbon dioxide
- Prior art date
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
- C23C8/06—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
- C23C8/28—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 more than one element being applied in one step
- C23C8/30—Carbo-nitriding
Definitions
- the invention relates to a method for nitrocarburizing metallic workpieces by treating the workpieces in a treatment atmosphere containing nitrogen, carbon monoxide and hydrogen at a treatment temperature in a treatment room, carbon dioxide being used as the carbon donor to generate the treatment atmosphere.
- the nitrogen donor is basically ammonia (NH 3 ), while various gas mixtures such as air-hydrocarbon mixtures (endogas and exogas) and carbon dioxide are used as carbon donors. In the nitriding furnace, these gases react with the hydrogen present, with stationary carbon, nitrogen and oxygen activity depending on the thermal and chemical conditions.
- the atomic nitrogen produced during ammonia splitting reacts particularly easily with the metal to form nitrides when it comes into contact with metal surfaces (hereinafter referred to as (N) a d).
- Different nitride phases can form in connection with iron.
- nitride phases in the form of so-called ⁇ -nitride (F ⁇ 2-3N) and ⁇ '-nitride (F ⁇ 4N) or mixtures of these nitrides, for example, are preferred with regard to high hardness and wear resistance.
- the reactions taking place during the nitride formation of Fe-containing metals can be described schematically using the following chemical equations:
- the carbon dissolved in the nitride affects morphology, compactness, pore hem and adhesion of the connection layer and its corrosion and Wear resistance.
- the type and extent of nitride formation is significantly influenced by the carbon activity in the nitriding atmosphere. The carbon activity in turn depends on the one used
- Carbon donor It drops in the order of propane, endogas, exogas and carbon dioxide. Since the composition of the gas phase in the nitriding furnace thus has a significant influence on the result of the nitrocarburization, it is advantageous if it can be set within as wide a range as possible.
- the carbon dioxide contents are usually between 4 and 10% by volume.
- the carbon dioxide is metered directly into the furnace chamber of the nitriding furnace, where it partially reacts with hydrogen according to the following reaction equation:
- a carbon activity (a c, B ), which is adapted to the prevailing conditions, settles down and can be defined according to the Boudouard reaction:
- K B denotes the constant of the Boudouard equilibrium.
- the maximum carbon activity is 1, which corresponds to the activity of pure graphite.
- K N nitriding index
- the known method is characterized in that the NH 3 gas throughput is kept constant and only the operating point of the pre-splitter in which the NH 3 split gas is generated is regulated.
- a high nitriding index requires a high ammonia content in the nitriding furnace, which in turn results in a high residual ammonia content in the furnace exhaust gas, which leaves the furnace unused.
- Substance such as methanol is fed into the furnace space.
- the CO-forming components such as methanol or CO 2 are thus fed directly into the treatment room.
- carburizing or carbonitriding this is effective due to the high temperatures involved, but not at the usual, relatively low nitriding temperatures of max. 580 ° C.
- methanol does not cleave stoichiometrically, but undesirable cleavage products such as CH 4 and other higher hydrocarbons, CO 2 , aldehydes, ketones, etc. are formed, some of which are toxic and corrosive when condensed.
- the cleavage of the methanol strongly depends on the conditions in the boiler room and on the surface of the batch, so that the desired furnace gas composition cannot be reproduced. This also has the consequence that soot deposits on the batch material and the boiler room surface due to uncontrolled cracking reactions or undesired carbides are formed.
- the invention is therefore based on the object of modifying the known method for nitrocarburizing metallic workpieces using carbon dioxide as a carbon donor so that the type and extent of nitride formation can be adjusted within a wide range.
- a carbon dioxide-containing gas stream is introduced into a reactor upstream of the treatment room and is modified therein by reaction with a hydrogen donor at a reaction temperature above the treatment temperature to give a carbonization gas which has a higher carbon activity than the carbon dioxide-containing gas stream at the treatment temperature.
- the gas stream containing carbon dioxide is fed to a reactor, modified therein in the direction of a higher carbon activity and then introduced into the treatment room as carbonizing gas.
- the modification is based on a
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)
- Preventing Corrosion Or Incrustation Of Metals (AREA)
- Chemical Or Physical Treatment Of Fibers (AREA)
Abstract
Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT00962293T ATE257865T1 (en) | 1999-08-25 | 2000-08-04 | PROCESS FOR NITROCARBURIZING METALLIC WORKPIECES |
DE50005043T DE50005043D1 (en) | 1999-08-25 | 2000-08-04 | METHOD FOR NITROCARBURING METAL WORKPIECES |
EP00962293A EP1230415B1 (en) | 1999-08-25 | 2000-08-04 | Method for nitro-carburization of metal workpieces |
PL00353217A PL195105B1 (en) | 1999-08-25 | 2000-08-04 | Method for nitro-carburization of metal workpieces |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19940370A DE19940370C2 (en) | 1999-08-25 | 1999-08-25 | Process for nitrocarburizing metallic workpieces |
DE19940370.8 | 1999-08-25 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2001014611A1 true WO2001014611A1 (en) | 2001-03-01 |
Family
ID=7919599
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2000/007576 WO2001014611A1 (en) | 1999-08-25 | 2000-08-04 | Method for nitro-carburization of metal workpieces |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP1230415B1 (en) |
AT (1) | ATE257865T1 (en) |
CZ (1) | CZ298996B6 (en) |
DE (2) | DE19940370C2 (en) |
ES (1) | ES2214316T3 (en) |
PL (1) | PL195105B1 (en) |
WO (1) | WO2001014611A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6801111B2 (en) * | 2002-08-21 | 2004-10-05 | Square D Company | Latch for an electrical device |
US7621201B2 (en) * | 2008-03-05 | 2009-11-24 | Gm Global Technology Operations, Inc. | Hot forming tools for aluminum and magnesium sheets |
DE102023133600A1 (en) * | 2022-12-01 | 2024-06-06 | Gottfried Pöckl | Process for nitriding components |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0024106A1 (en) * | 1979-07-09 | 1981-02-25 | Ford Motor Company Limited | Method of heat treating ferrous workpieces |
JPH01129957A (en) * | 1987-11-13 | 1989-05-23 | Toyota Motor Corp | Surface treatment for maraging steel |
DE3937699A1 (en) * | 1989-11-13 | 1991-05-16 | Thaelmann Schwermaschbau Veb | Producing epsilon carbonitride coatings on ferrous components - by controlling gas mixt. compsn. with respect to nitriding and carburising indices required to produce predetermined coating compsn. |
DE19652125C1 (en) * | 1996-12-14 | 1998-04-30 | Volker Dipl Ing Leverkus | Nitriding or carbonitriding atmosphere regulation |
DE19719225C1 (en) * | 1997-05-07 | 1998-08-06 | Volker Dipl Ing Leverkus | Method and apparatus for controlling a nitriding or nitro-carburising atmosphere |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4229803A1 (en) * | 1992-09-11 | 1994-03-17 | Iva Industrieoefen Verfahren A | Control of nitriding and nitro:carburising atmospheres - by oxygen probe using fully dissociated gas as reference gas |
DE19514932A1 (en) * | 1995-04-22 | 1996-10-24 | Ipsen Ind Int Gmbh | Method and device for regulating the CO content of an oven atmosphere for carburizing and carbonitriding metallic workpieces |
-
1999
- 1999-08-25 DE DE19940370A patent/DE19940370C2/en not_active Expired - Fee Related
-
2000
- 2000-08-04 AT AT00962293T patent/ATE257865T1/en not_active IP Right Cessation
- 2000-08-04 PL PL00353217A patent/PL195105B1/en unknown
- 2000-08-04 DE DE50005043T patent/DE50005043D1/en not_active Expired - Lifetime
- 2000-08-04 EP EP00962293A patent/EP1230415B1/en not_active Expired - Lifetime
- 2000-08-04 ES ES00962293T patent/ES2214316T3/en not_active Expired - Lifetime
- 2000-08-04 WO PCT/EP2000/007576 patent/WO2001014611A1/en active IP Right Grant
- 2000-08-04 CZ CZ20020645A patent/CZ298996B6/en not_active IP Right Cessation
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0024106A1 (en) * | 1979-07-09 | 1981-02-25 | Ford Motor Company Limited | Method of heat treating ferrous workpieces |
JPH01129957A (en) * | 1987-11-13 | 1989-05-23 | Toyota Motor Corp | Surface treatment for maraging steel |
DE3937699A1 (en) * | 1989-11-13 | 1991-05-16 | Thaelmann Schwermaschbau Veb | Producing epsilon carbonitride coatings on ferrous components - by controlling gas mixt. compsn. with respect to nitriding and carburising indices required to produce predetermined coating compsn. |
DE19652125C1 (en) * | 1996-12-14 | 1998-04-30 | Volker Dipl Ing Leverkus | Nitriding or carbonitriding atmosphere regulation |
DE19719225C1 (en) * | 1997-05-07 | 1998-08-06 | Volker Dipl Ing Leverkus | Method and apparatus for controlling a nitriding or nitro-carburising atmosphere |
Non-Patent Citations (2)
Title |
---|
E. VYTEV: "GAS NITRIDING IN A MEDIUM OF AMMINIA AND CARBON DIOXIDE", METAL SCIENCE & HEAT TREATMENT, vol. 23, no. 1/2, January 1981 (1981-01-01) - February 1981 (1981-02-01), new york,usa, pages 29 - 32, XP002154202 * |
PATENT ABSTRACTS OF JAPAN vol. 013, no. 379 (C - 628) 22 August 1989 (1989-08-22) * |
Also Published As
Publication number | Publication date |
---|---|
EP1230415B1 (en) | 2004-01-14 |
ATE257865T1 (en) | 2004-01-15 |
CZ2002645A3 (en) | 2003-02-12 |
CZ298996B6 (en) | 2008-04-02 |
PL353217A1 (en) | 2003-11-03 |
DE19940370C2 (en) | 2001-07-12 |
PL195105B1 (en) | 2007-08-31 |
EP1230415A1 (en) | 2002-08-14 |
DE19940370A1 (en) | 2001-03-01 |
ES2214316T3 (en) | 2004-09-16 |
DE50005043D1 (en) | 2004-02-19 |
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