EP2578704A1 - Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente - Google Patents

Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente Download PDF

Info

Publication number
EP2578704A1
EP2578704A1 EP11008118.9A EP11008118A EP2578704A1 EP 2578704 A1 EP2578704 A1 EP 2578704A1 EP 11008118 A EP11008118 A EP 11008118A EP 2578704 A1 EP2578704 A1 EP 2578704A1
Authority
EP
European Patent Office
Prior art keywords
carbon
carbonitriding
metallic component
carburizing
hydrocarbon material
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.)
Withdrawn
Application number
EP11008118.9A
Other languages
English (en)
French (fr)
Inventor
Anders ASTRÖM
Sören Wiberg
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.)
Linde GmbH
Original Assignee
Linde 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 Linde GmbH filed Critical Linde GmbH
Priority to EP11008118.9A priority Critical patent/EP2578704A1/de
Publication of EP2578704A1 publication Critical patent/EP2578704A1/de
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/18—Hardening; Quenching with or without subsequent tempering
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
    • C21D1/34—Methods of heating
    • C21D1/53—Heating in fluidised beds
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • 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

Definitions

  • the invention relates to a method and a system for carburizing or carbonitriding a metallic component and a correspondingly treated metallic component.
  • This problem can be solved by using a low carbon content steel in machining a component to its final form and dimensions and then carburizing its surface, i.e. increasing its carbon content.
  • the component comprises a hard case and a softer core.
  • the case attains a hardness corresponding to its elevated carbon content while the core maintains its low carbon concentration and corresponding lower hardness.
  • a similar effect is obtained by carbonitriding.
  • Carburizing and carbonitriding is typically performed as a heat treatment process carried out at a temperature where steel is austenitic, typically in a temperature range of 820 - 950 °C, and under a controlled furnace atmosphere at slight overpressure. Under such conditions, carbon or carbon and nitrogen is transferred from the atmosphere to the steel surface.
  • the terms carburizing and carbonitriding are typically understood to include hardening, and thus quenching, as the final step. In this step, the carburized or carbonitrided case transforms to a martensite microstructure constituent.
  • case hardening is sometimes alternatively used to more clearly describe the fact that the process includes the hardening step.
  • ready-machined parts for instance gears
  • the basket or fixture is placed in a furnace containing a defined atmosphere and typically being held at the above mentioned temperatures.
  • a transfer of carbon from the gas to the steel surface begins.
  • Carburizing is allowed to proceed until the desired depth of penetration is reached.
  • the charge is then moved from the heating chamber to a gas tight cooling chamber integrated into the furnace where it is rapidly quenched in an oil bath. After cooling, the charge undergoes washing, tempering and further treatment.
  • gas compositions for use in carburization or carbonitriding furnaces are known and details are omitted for conciseness. Briefly, the functions of the furnace atmosphere are to supply the necessary carbon (and nitrogen), to provide the correct carbon (and nitrogen) content, to buffer from disturbances, to purge, to give uniform results, to maintain a positive pressure and to permit safety purging.
  • Gas compositions typically used include carbon monoxide, methane and/or hydrogen, and typical carbon transfer reactions are e.g. given by the equations 2 CO ⁇ C + CO 2 CH 4 ⁇ C + 2H 2 and/or CO + H 2 ⁇ C + H 2 O.
  • a problem frequently observed in carburizing processes is internal oxidation. This process takes place during any heat treatment of a metal in an environment which contains oxygen or oxygen compounds if the metal has a certain solubility for oxygen, if the metal contains alloying elements with a higher affinity for oxygen than the parent metal, and if the diffusion rate of oxygen in the parent metal is higher than that of such alloying elements.
  • Commercial steels fulfill these requirements.
  • typical gas compositions used in carburization furnaces also incude, at least bound, oxygen.
  • oxide arms of considerable extent are formed by alloying elements such as chromium, manganese and silicon. These oxide arms impair the steel matrix by alloy depletion, resulting in so-called High Temperature Transformation Products (HTTP) and leading to decreased hardenability, and/or by inducing a brittle behavior due to the oxide arms acting as crack initiation sites. Internal oxidation is therefore detrimental as to fatigue strength, especially on dynamically loaded components. Historically, oxide layers were removed by heat treatment, machining or grinding. Post treatment steps, however, are costly and time consuming and should thus be avoided.
  • HTTP High Temperature Transformation Products
  • carburizing While the following description primarily refers to “carburizing”, it should be understood that the inventive concepts are advantageous in both carburizing and carbonitriding processes. Furthermore, special types of carburizing and carbonitriding processes, e.g. vacuum, plasma, pack and liquid drip feed carburizing, have been developed over the years and the invention may equally be advantageous in such special processes.
  • special types of carburizing and carbonitriding processes e.g. vacuum, plasma, pack and liquid drip feed carburizing
  • a carbon rich layer is formed on at least a part of a metallic component prior to exposing the metallic component to the carburizing or carbonitriding conditions in a carburizing or carbonitriding furnace.
  • the carbon rich layer is formed from carbon or from a suitable material as described below.
  • the invention suggests performing a pretreatment step before carburizing or carbonitriding.
  • the pretreatment step involves forming a carbon rich layer on the metallic component which acts as an oxygen interceptor or scavenger and locally reduces oxygen content.
  • the carbon rich layer forms a layer of locally higher reducing capacity in solid and/or gaseous form when exposed to the carburization or carbonitriding conditions as compared to the surrounding atmosphere, involving reactions such as C + O 2 ⁇ CO + 1/2 O 2 , C + H 2 O ⁇ CO + H 2 and/or C + CO 2 ⁇ 2 CO .Therefore, internal oxidation is reduced. Consequently, oxides are formed to a lesser extent and with reduced depth.
  • a first general concept is to combust an understoichiometric mixture of the carbon or of the hydrocarbon material with air and/or oxygen and to deposit and/or apply the combustion products on the component to be carburized or carbonitrided.
  • This ignition is advantageously performed in an ignition chamber.
  • the carburizing or carbonitriding furnace or chamber may be used. Pretreatment, i.e. the formation of the carbon rich layer, carburizing or carbonitriding, and possible further treatment may thus be performed in a single chamber without the need for additional system components.
  • An alternative, yet advantageous method for depositing the carbon rich layer that involves combustion is performed by using a burner supplied with at least the carbon or the hydrocarbon material and air or oxygen.
  • a burner supplied with at least the carbon or the hydrocarbon material and air or oxygen.
  • a targeted application of the carbon rich layer may be performed in specific parts or selected regions of the metallic components to be treated.
  • metallic components e.g. via a conveyer
  • application of the carbon rich layer can be performed using a hand held burner or a programmed robot.
  • a second general concept to apply a carbon or a carbon rich layer on a metallic component involves using a sprayer which is adapted for spraying the carbon or the hydrocarbon material onto at least a part of the component.
  • Spraying may involve spraying e.g. waxes, graphite, water/oil or water/oil/alcohol suspensions or gels as the carbon or the hydrocarbon material.
  • Special care needs to be taken to avoid evaporation of the carbon or the hydrocarbon material before the carburizing or carbonitriding temperatures are reached.
  • a reducing gaseous amosphere is obtained locally.
  • the carbon rich layer can be it via a burner or a sprayer, can be performed via a fixed burner installation, e.g. including a conveyor, by a robot, or manually.
  • the carbon rich layer may be applied to individual metallic components or, with significant savings in time and material, to several components stacked or mounted to a support as previously mentioned.
  • a carbon or hydrocarbon material to be used according to the invention advantageously includes at least one component selected from the group consisting of acetylene, methane, ethane, propane, C4 to C14 linear and cyclic alkanes, alkenes, alcohols and aromatic hydrocarbons, natural gas, graphite powder, waxes, mineral oils, kerosene, and mixtures thereof.
  • Selection of the specific carbon or hydrocarbon material may depend on the mode of application, i.e. whether spraying or combustion is to be performed.
  • Especially advantageous hydrocarbon materials for combustion are acetylene, propane or natural gas.
  • advantageous hydrocarbon materials for spraying include waxes, graphite, water/oil, water/oil/alcohol suspensions or gels or kerosene.
  • An inventive carburization or carbonitriding method advantageously includes exposing the pretreated metallic components to carburizing or carbonitriding conditions including a temperature range of 820°C to 1080°C and a gas atmosphere containing at least carbon monoxide, methane and/or hydrogen.
  • this ignition chamber can be used as a carburizing or carbonitriding furnace for providing these conditions.
  • a metallic component according to the invention is obtained or obtainable by a method or in a system as described above.
  • Such a metallic component will typically comprise significantly lower oxygen contents and a significantly lower oxidation layer thickness.
  • oxide arms in internal oxidation grow with about 1 micrometers per hour under conventional carburization or carbonitriding conditions, reaching, e.g in automotive components, 7 to 14 micrometers depending on the specific process and furnace.
  • a metallic component according to the invention will show significantly shorther oxide arms.
  • Figure 1 shows an arrangement 10 for applying a carbon rich layer on a metallic component usable in a method for carburizing or carbonitriding metallic component.
  • the arrangement 10 includes an ignition and/or combustion chamber 2 which is adapted to be supplied with a combustible carbon or hydrocarbon material via a feed 21.
  • the ignition and/or combustion chamber 2 comprises an interior space 35 which is dimensioned to accommodate a stack or pile of metallic components 1 to be treated according to the invention.
  • the ignition and/or combustion chamber 2 is provided with a gas supply 36 comprising, besides the mentioned feed 21 for the combustible carbon or hydrocarbon material, gas tubes or feeds 22 and 23. Via feeds 22 and 23 air, oxygen or a combustible gas for providing a pilot or ignition flame can be supplied to the interior space 35 of the ignition and/or combustion chamber 2.
  • Typical gas atmospheres provided within the ignition and/or combustion chamber 2 comprise, as mentioned, hydrocarbon materials, air and/or oxygen.
  • an ignition device 34 may be provided.
  • FIG. 2 shows a further arrangement 20 for applying a carbon rich layer on metallic components 1 according to the invention.
  • the arrangement 20 comprises a burner 3 with corresponding gas feeds 31 - 33.
  • the gas feeds 31 - 33 may be supplied via corresponding gas tubing with gases like those mentioned in relation to Figure 1 .
  • gas feeds 31 - 33 are provided to supply streams of a hydrocarbon material (feed 31), air and/or oxygen (feed 32) and combustible gases to provide a pilot flame (feed 33).
  • feed 31 hydrocarbon material
  • feed 32 air and/or oxygen
  • feed 33 combustible gases
  • pilot flame feed 33
  • understochimetric gas mixtures are provided.
  • the burner 3 comprises a burner head 34 for providing a burner flame 35. Stacked and/or piled metallic components 1 may be moved below the burner 35 via a corresponding conveyer (not shown).
  • the burner 3 is fixed to a burner mount 36 which may be attached to a holding structure and/or a robot. Alternatively, burner 3 may be embodied as a hand held burner 3.
  • FIG. 3 schematically shows a method 100 according to the invention.
  • Method 100 involves, at step 110, forming or applying a carbon rich layer on one or more metallic component(s), and, after application of the carbon rich layer, exposing 120 the metallic component(s) to carburization or carbonitriding conditions. After the exposition step 120, the metallic component(s) may be quenched and/or hardened 130.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
EP11008118.9A 2011-10-07 2011-10-07 Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente Withdrawn EP2578704A1 (de)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP11008118.9A EP2578704A1 (de) 2011-10-07 2011-10-07 Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP11008118.9A EP2578704A1 (de) 2011-10-07 2011-10-07 Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente

Publications (1)

Publication Number Publication Date
EP2578704A1 true EP2578704A1 (de) 2013-04-10

Family

ID=44860203

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11008118.9A Withdrawn EP2578704A1 (de) 2011-10-07 2011-10-07 Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente

Country Status (1)

Country Link
EP (1) EP2578704A1 (de)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1189046A (en) * 1967-03-23 1970-04-22 Gold Und Silberscheidean Stalt An Annealing Furnace for the Bright Annealing of Workpieces
GB1438550A (en) * 1973-08-09 1976-06-09 Fluidfire Dev Heat treatment furnace
GB1489106A (en) * 1974-03-18 1977-10-19 Hawera Probst Kg Hartmetall Hardening of steel workpieces
GB1505727A (en) * 1974-07-20 1978-03-30 Messer Griesheim Gmbh Method of producing a heat-treatment gas
EP0024106A1 (de) * 1979-07-09 1981-02-25 Ford Motor Company Limited Verfahren zur Wärmebehandlung von Werkstücken aus Eisen

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1189046A (en) * 1967-03-23 1970-04-22 Gold Und Silberscheidean Stalt An Annealing Furnace for the Bright Annealing of Workpieces
GB1438550A (en) * 1973-08-09 1976-06-09 Fluidfire Dev Heat treatment furnace
GB1489106A (en) * 1974-03-18 1977-10-19 Hawera Probst Kg Hartmetall Hardening of steel workpieces
GB1505727A (en) * 1974-07-20 1978-03-30 Messer Griesheim Gmbh Method of producing a heat-treatment gas
EP0024106A1 (de) * 1979-07-09 1981-02-25 Ford Motor Company Limited Verfahren zur Wärmebehandlung von Werkstücken aus Eisen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
"Linde Gas", 2007, article "Furnace Atmospheres No. 1 - Gas Carburizing and Carbonitriding"

Similar Documents

Publication Publication Date Title
US20150159259A1 (en) Low Alloy Steel Carburization and Surface Microalloying Process
CN1263887C (zh) 真空碳氮共渗方法
US4049472A (en) Atmosphere compositions and methods of using same for surface treating ferrous metals
Kulka et al. An alternative method of gas boriding applied to the formation of borocarburized layer
Edenhofer et al. Carburizing of steels
US20080120843A1 (en) Method for manufacturing low distortion carburized gears
Maldzinski et al. ZeroFlow gas nitriding of steels
US8425691B2 (en) Stainless steel carburization process
EP2653569B1 (de) Chromhaltiger stahl für lager mit hohem kohlenstoffanteil und herstellungsverfahren dafür
US20220042158A1 (en) Nitriding process for carburizing ferrium steels
US3519257A (en) Process for the treatment of surfaces of workpieces in an annealing furnace
US4776901A (en) Nitrocarburizing and nitriding process for hardening ferrous surfaces
EP2578704A1 (de) Verfahren und System zum Aufkohlen oder Karbonitrieren einer Komponente und entsprechend behandelte Komponente
Rokicki et al. Acetylene flow rate as a crucial parameter of vacuum carburizing process of modern tool steels
Konno et al. Characterization of carburized layer on low-alloy steel fabricated by hydrogen-free carburizing process using carbon ions
JP2010222636A (ja) 鋼材の表面処理方法
EP3168314A1 (de) Verfahren zur wärmebehandlung metallischer werkstücke
Herring A case for acetylene based low pressure carburizing of gears
WO2008083033A3 (en) Method for oxygen free carburization in atmospheric pressure furnaces
JP6542381B2 (ja) 物品を処理するための方法および装置
JP4858071B2 (ja) 鋼材の表面処理方法及び表面処理された鋼材
CA1036912A (en) Heat treatment of ferrous metals in controlled gas atmospheres
Belotserkovskii et al. Structural-Phase Condition and Wear Resistance of Gasothermal Coatings from High-Chromium Steels Modified with Nitrogen Ions and Sprayed with the use of High-Enthalpy Combustible Gas
Loeser et al. Low pressure carburizing of large transmission parts
Gundel A Novel Oxygen Free Ferritic Nitro Carburizing Process

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20131011