US3201290A - Process for automatically controlled carburizing of the surface layer of steel articles - Google Patents

Process for automatically controlled carburizing of the surface layer of steel articles Download PDF

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Publication number
US3201290A
US3201290A US311134A US31113463A US3201290A US 3201290 A US3201290 A US 3201290A US 311134 A US311134 A US 311134A US 31113463 A US31113463 A US 31113463A US 3201290 A US3201290 A US 3201290A
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gas
carburizing
furnace
substance
carbon
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US311134A
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English (en)
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Wyss Urs
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Maag Gear Wheel and Machine Co Ltd
Maag Zahnrader und Maschinen AG
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Maag Zahnrader und Maschinen AG
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    • 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
    • C21D1/76—Adjusting the composition of the atmosphere
    • 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
    • C23C8/08—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 only one element being applied
    • C23C8/20—Carburising
    • C23C8/22—Carburising of ferrous surfaces

Definitions

  • the carburizing gases are produced in an appropriate gas generator, then either supplied to the carburizing furnace with the required composition or supplied to the furnace as a carrier gas having a very reduced carburizing action. In the latter case, gas which has a stronger carburizing action is supplied to the furnace additionally.
  • the carburizing gases are produced in the carburizing furnace by cracking of continuously supplied appropriate and, normally preferably, liquid substances.
  • This group of processes will be referred to hereinafter as drip feed processes, even in cases Where the liquids are gasified before they enter the furnace.
  • Group (a) processes have the great disadvantage that the operation of a generator may be uneconomical. It is known to use for gas carburizing one gas, having the approximate composition /sCO
  • Sampling of carburizing gas from the furnace chamber can only be done if enough gas is developed by feeding the carburizing liquid. Feeding this liquid is of course also dependent on the carbon demand of the steel surface to be car'ourized. If the surface is small, only a small feeding rate of the carburizing mixture is necessary and hence a too small amount of gas is developed to allow extraction. In this case, by pumping sample gas from the furnace chamber, air would be sucked through the joints into the furnace, spoiling the atmosphere and rendering impossible an effective control of the carbon potential in this way. It isfurther a usual practice to set a high carbon potential (1.2 to 1.3%) during the first period and a lower one (0.8%) for the second period of the carburizing cycle (see the accompanying FIG. 5).
  • the feeding rate of the liquid carburizing mixture has to be reduced to very low values or has to be shut off completely during the second period, with the effect that although the surface to be carburized is large, only a small quantity of gas is developed inside the carburizing furnace. This quantity is mostly much smaller than the necessary amount for sampling gas and to compensate leakage.
  • a process for controlling automatically the carburizing of the surface layer of steel articles by gas carburizing in a gas atmosphere formed in a furnace chamber by thermal decomposition is characterised in that a combination of separately fed substances of which one yields a carrier gas, that is, a gas merely producing a positive pressure, and :another yields a carburizing gas, is used, the combination being such that during the cracking and carburizing reactions, the resulting two gases provide substantially the same and a substantially constant gas composition, and the supply of the gas-providing substances, preferably of the substance yielding the carburizing gas, is controlled by continuously determining the content of one constituent of the furnace gases. Such determinations may be preformed by instrumentation.
  • carburizing gas that is, a gas which causes a considerable carbur-izing effect of the articles in contrast to the carrier gas which has little, if any, carburizing action, a substance such as provides the same gas composition by the carburizing reaction as the carrier gas, so that throughout the carbu'rizing treatment, the atmosphere in the furnace is constant regardless of the proportion of carrier-gas-forming substance to carburizing substance.
  • the substances which provide the carrier gas and the car-burizing gas are preferably introduced as two organic liquids, either together or separately, into the hot heat carburizing furnace at temperatures higher than 800, usually between 850 to 1000 (1., and they may be evaporated before entering the furnace.
  • the substances are dissociated in the furnace and yield the required gas atmosphere.
  • FIG. 1 is a diagrammatic sectional elevation of an apparatus for carrying out the process according to the invention
  • FIG. 2 is a graph showing the consumption of carbon or equivalent amounts of isopropanol or ethyl acetate needed to secure the indicated growth of the case depth, depending on time and surface area for temperatures of 850 (3., 900 C., and 950
  • FIG. 3 is a graph showing the feeding rate of carbon or the equivalent feeding rates of isopropanol or ethyl acetate connected with the necessary consumption shown in FIG. 2 to secure the indicated growth of the carburized case;
  • FIG. 4 is a graph showing the CO-contents of the furnace atmosphere relative to varying ratios of various liquids providing the said atmosphere;
  • FIG. 5 is a graph showing the carbon penetration in the carburized case after different carburizing times at 950 C. for a nickel-chrome-carburizing steel.
  • FIG. 6 is a graph showing the relation between dew point (water content) of the furnace gas, carbon potential and furnace temperature in the process according to the present invention.
  • the gas is caused to flow in the direction indicated by arrows by the arrangement comprising the fan 8, a .top battle 9 and a lateral bafi'le It
  • a pipe 11 extends through the top baffle 9 and the cover t and conveys gas, from inside the baffles 9, 10, which burns with a flame 12 to give a check on the positive pressure in the furnace.
  • the positive pressure in the furnace is satisfactory, provided that the gas remains alight at the flame 12.
  • the cover 4 is provided with at least one pipe 13 for the supply into the retort 3 of liquid substances for producing the gas atmosphere.
  • Connected to the pipe 11 is another waste gas pipe 14 through which gas can be pumped from the furnace for sampling and for supply to an analyser J15.
  • the analyser can be any appropriate apparatus which will de termine the CO content of the sample gas sufficiently accurately. If the H 0 content of the gas is to be controlled, the gas analyser must take the form of an apparatus for determining the Water content, preferably for determining the dewpoint of the sample gas.
  • the measurement results of the analyser 15 (sensitive element) are supplied to an automatic control device 16 of the kind conventional in the control and regulation art. Depending upon the gas atmosphere in the furnace and upon the programme set up for the carbon potential, that is, the re quired carbon consumption, the device 16 operates a valve 17 disposed in a pipe from a tank 18 for the supply of a liquid yielding a carburizing gas.
  • a liquid which provides the carrier or positive pressure gas is disposed in a vessel 19 and flows through a valve 20 to the common supply pipe 13 where the two liquids are mixed with one another, although they can be supplied separately.
  • the two tanks 18, 19 are so disposed that, when the valves 17 and 20 are open, the liquids can drip into the supply pipe 13 by their hydrostatic pressure and without or with the use of an injection pump.
  • the liquids or the mixtures thereof evaporate and are cracked thermally between the baffles 9, ltl and the wall of the retort 3.
  • the gas mixture is circulated by the fan 8, as indicated by the arrows, the gas stream passing uniformly over all workpieces 7. N0 soot is deposited on the workpieces 7.
  • aliphatic hydrocarbons, or monovalent or polyvalent alcohols, aldehydes or ketones having from 1 to 5 carbon atoms can be used provided that they are injected in a mixture with such a quantity of water that the atomic-ratio of (3:0 in the mixture 'is substantially as hereinbefore specified.
  • Cheap methanol has given satisfactory results in all circumstances. 7
  • the liquid for forming the carrier gas that is, producing the positive pressure
  • a compound or a mixture of compounds in which the C10 ratio is greater than unity for instance, a mixture of 1 mol of isopropanol and 1 'mol of methanol.
  • the quantities of such substances or the C:O ratio is apmixtures which sufiice to provide a pressure slightly above atmosphere are small enough for their carburizing effect to be only very slight on large workpiece areas.
  • an organic compound is used of a kind which yields a strongly carburizing gas in cracking.
  • intermediate products may be formed, such as methane which, of course, is a very strong carburizing agent, but the automatic control of the CO or H O contents keeps the methane contents below 2%.
  • More particularly suitable are substances in which the C:O ratio is greater than 115:1, preferably between 221 and 3:1 or even greater than 3:1.
  • aliphatic-hydrocarbons having from 1 to 20 carbon atoms, preferably 1 to 4 carbon atoms, and their monovalent and polyvalent alcohols, aldehyde-s, ketones, ethers, esters and the like, mixed, it required, with appropriate quantities of water, and preferably isopropyl alcohol, acetone or methyl acetate and ethyl acetate.
  • the gas composition must be maintained substantially constant throughout the carburizing treatment if Methanol cracks at furnace temperatures above 800 C. into a mixture consisting mainly of /3 CO and /3 of H according to the idealized reaction equation:
  • the evolution of carbon in the furnace is to be controlled automatically by controlling a constituent of the waste gas.
  • a constituent of the waste gas one is chosen which, after yielding carbon to the surface of workpieces by the cracking and carburizing reactions, leads to the same composition of the furnace atmosphere as is provided by the substance producing the carrier gas, that is the positive pressure.
  • FIG. 2 shows the time dependence of the consumption of equivalent amounts of carbon, isopropanol or ethylacetate for surface areas of workpieces from 1 to 75 m. and for temperatures of 850 C., 900 C. and 950 C. each for a growth of the effective case depth of the carburized layer as indicated by the dashed lines De.
  • the corresponding feeding rate of the carburizers necessary to maintain the indicated growing rate of the case is shown in FIG. 3.
  • the FIGS. 2 and 3 are valid for all types of the usual carburizing steel on condition that carbon potentials of 1.05% at a temperature of 850 C., 1.15% at 900 C. and 1.30% at 950 C. are maintained.
  • the necessary feeding rate for methanol to compensate sampling gas and leakage and to maintain the desired positive pressure inside the furnace corresponds to 300 to 600 g. (approx. /3 to 1 /3 pounds) per hour.
  • the feeding rate for the carburizing liquid follows from FIG. 3, but is automatically adapted to the instantaneous demand through continuously controlling the dew point or the CO content of the furnace gas as described.
  • reaction gas is exactly the same for methanol, ethyl acetate and a mixture of acetone and methyl acetate in a molar ratio of 1:1.
  • methanol as a liquid providing a carrier gas, is associated with ethyl acetate providing the carburizing gas.
  • the same ratio of CO to H is formed as is already shown by the cracking reaction of methanol.
  • FIG. -4 shows clearly why the difiiculties arise when endeavours are made to control such a system by controlling one particular gas constituent, for example, C0
  • acetone makes an excellent carburizing agent, for instance, in combination with a carrier-gasiorming or positive-pressure-maintaining mixture of methanol and isopropanol in the molar ratio of 1:1; the supply of acetone is controlled automatically and sothere is no change in gas composition throughout the carburizing process.
  • the constant CO contents are 25%, compared with a combination of methanol and ethyl acetate where the CO contents are 33%. If, therefore, a particular carbon level is to be maintained in either combination, the CO or H O contents of the furnace gas must be controlled appropriately.
  • a small constant quantity of ethyl acetate (instead of methanol) can be supplied continuously just to maintain a slight positive pressure to compensate leakage and sampling gas.
  • An extra quantity of ethyl acetate is supplied automatically through the agency of apparatus con trolled in accordance with the CO or H O contents. This step is another method of providing a constant carburizing atmosphere.
  • Carburizing steels to which this process has been applied contain 0.06 to 0.27% carbon, 0.10 to 0.60% silicon, 0.3 to 0.9% manganese, to 2.5% chromium, 0 to 4.5% nickel, 0 to 0.8% molybdenum.
  • FIG. 5 shows typical carbon penetration curves after 1 /3, 4, 12, 25 and 36 hours carburizing time .at 950 C. for a steel containing 0.12% carbon, 0.31% silicon,
  • FIG. 6 represents the relation between dew point and carbon potential for different furnace temperatures.
  • the dew point can be set with the control instrument No. 16 of FIG. 1, according to this graph.
  • This graph is valid for methanol as carrier gas forming liquid associated with .carburizing liquids like ethyl acetate, acetone plus methyl acetate (molar ratio 1:1), acetone alone, isopropanol (10 parts) plus water (3 parts) or for relatively small surfaces also for isopropanol alone.
  • the process according to the invention has considerable advantages over the prior .art systems, namely, exact maintenance of the required carbon potential and of the required penetration depth, independence from the size of the surface area to :be carburised and therefore from the required amount of carburizing substance, no deposits of soot or other residues on the workpiece surfaces and therefore no cleaning, very reduced gas consumption, no complicated and expensive fittings for producing, conveying, measuring and controlling large volumes of gas, lowcost and readily available substances for the gas atmosphere, no extra apparatus for gas generation such as sep arate gas generators, the gas being generated merely by the liquids specified dropping into the furnace chamber, possibility of controlling either of the liquid supplies, and continuance of furnace charge Without disturbances in operation and losses even though the supply or dispensing of the controlled liquid or the heating fails temporarily because of an interruption in electricity supply.
  • Process characterised in that the supply of the carburizing gas-providing substances is controlled by controlling the CO content of the furnace atmosphere.
  • Process according to claim 1 characterised in that methanol is used as the substance providing the pressure producing gas, and the substance providing the car'ourizing gas is a mixture of isopropanol with water.
  • Process according to claim 1 characterised in that methanol is used as the substance providing the pressure producing gas, and the substance providing the carburizing gas is acetone.
  • the method of automatically effecting the desired degree of carburization which comprises feeding into a furnace chamber a combination of hydrocarbon substances, one or" which yields a gas producing a positive pressure in said chamber, and another of which yields a carburizing gas, the combination of said substances being such that, after the cracking and the carburization reactions resulting therefrom, the gases providing the gas atmosphere in the furnace chamher have substantially the same composition as each other and maintaining said gas mixture substantially constant by controlling the feeding rate of the carburizing gas producing substance to compensate for breakdown thereof during carburizing treatment of the articles, in consonance with continuously determining the content of one constituent of the furnace gases throughout the carburizing treatment.
  • control of the feeding rate of the substance yielding the carburizing gas during the carburizing treatment is controlled by the water content of the furnace atmosphere.
  • control of the feeding rate of the substance yielding the carburiz ing gas during the carburizing treatment is controlled by the CO content of the furnace atmosphere.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Physics & Mathematics (AREA)
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  • Crystallography & Structural Chemistry (AREA)
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US311134A 1960-06-17 1963-09-24 Process for automatically controlled carburizing of the surface layer of steel articles Expired - Lifetime US3201290A (en)

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CH693460A CH404338A (de) 1960-06-17 1960-06-17 Verfahren zum regelbaren Aufkohlen der Oberflächenschicht von Werkstücken aus Stahl

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BE (1) BE605100A (de)
CH (1) CH404338A (de)
DE (1) DE1192486B (de)
FR (1) FR1292199A (de)
GB (1) GB911479A (de)
IT (1) IT649978A (de)
NL (2) NL266000A (de)

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3397875A (en) * 1966-05-20 1968-08-20 Leeds & Northrup Co Apparatus for maintaining a carburizing atmosphere during heat treatment
US3876410A (en) * 1969-12-24 1975-04-08 Ball Brothers Co Inc Method of applying durable lubricous coatings on glass containers
US3970037A (en) * 1972-12-15 1976-07-20 Ppg Industries, Inc. Coating composition vaporizer
US3989004A (en) * 1974-08-15 1976-11-02 Ball Corporation Apparatus for applying durable lubricous coatings to newly formed vitreous surfaces
US4016011A (en) * 1975-04-02 1977-04-05 Kabushiki Kaisha Fujikoshi Method for heat treatment of high alloy steel in a nonexplosive atmosphere
US4145232A (en) * 1977-06-03 1979-03-20 Union Carbide Corporation Process for carburizing steel
US4154629A (en) * 1975-12-23 1979-05-15 Kabushiki-Kaisha Fujikoshi Process of case hardening martensitic stainless steels
US4183982A (en) * 1977-05-09 1980-01-15 Balzers Aktiengesellschaft Fur Hochvakuumtechnik Und Dunne Schichten Fluid protective wall cover in a vapor deposition chamber
US4249965A (en) * 1978-09-19 1981-02-10 Midland-Ross Corporation Method of generating carrier gas
DE2943585A1 (de) * 1979-10-29 1981-04-30 Hollingsworth Gmbh, 7265 Neubulach Verfahren zum erhoehen der haerte und verschleissfestigkeit der oberflaeche eines staehlernen werkstuecks
US4306918A (en) * 1980-04-22 1981-12-22 Air Products And Chemicals, Inc. Process for carburizing ferrous metals
US4317687A (en) * 1980-05-12 1982-03-02 Air Products And Chemicals, Inc. Carburizing process utilizing atmospheres generated from nitrogen-ethanol based mixtures
EP0063655A1 (de) * 1981-04-27 1982-11-03 Air Products And Chemicals, Inc. Verfahren zum Aufkohlen von Eisenmetallen
US4386973A (en) * 1981-05-08 1983-06-07 General Signal Corporation Vacuum carburizing steel
EP0096104A1 (de) * 1982-06-14 1983-12-21 Linde Aktiengesellschaft Verfahren zum Herstellen einer Stickstoff und Wasserstoff enthaltenden Gasatmosphäre
US4632707A (en) * 1985-04-09 1986-12-30 Air Products And Chemicals, Inc. Protective atmosphere process for annealing and/or hardening ferrous metals
FR2623209A1 (fr) * 1987-11-17 1989-05-19 Air Liquide Procede de traitement thermique sous atmosphere gazeuse a base d'azote et d'hydrocarbure
US5186764A (en) * 1990-02-13 1993-02-16 Viscodrive Gmbh Method and apparatus for treating plates with gas
US20120325372A1 (en) * 2010-12-17 2012-12-27 Raghavan B Method for reduction of time in a gas carburizing process and cooling apparatus utilizing a high speed quenching oil flow rate
CN103276343A (zh) * 2013-06-17 2013-09-04 上海汇森益发工业炉有限公司 多用炉可控气氛渗碳方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4359351A (en) 1979-10-23 1982-11-16 Air Products And Chemicals, Inc. Protective atmosphere process for annealing and or spheroidizing ferrous metals
CH643597A5 (de) * 1979-12-20 1984-06-15 Maag Zahnraeder & Maschinen Ag Verfahren zum regelbaren aufkohlen oder erwaermen in schutzgas von werkstuecken aus stahl.
DE3038081A1 (de) * 1980-10-08 1982-05-06 Linde Ag, 6200 Wiesbaden Verfahren zum aufkohlen und kohlungsneutralen gluehen von werkstuecken
DE3139462A1 (de) * 1981-10-03 1983-04-21 Brown, Boveri & Cie Ag, 6800 Mannheim Verfahren zur herstellung von fe(pfeil abwaerts)2(pfeil abwaerts)b-schichten auf werkstcken aus eisenbasislegierungen

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2161162A (en) * 1938-01-06 1939-06-06 Leeds & Northrup Co Method of carburizing
US2329896A (en) * 1941-01-28 1943-09-21 Leeds & Northrup Co Method of and compound for carburizing
GB629879A (en) * 1947-12-30 1949-09-29 Gen Electric Co Ltd Improvements in or relating to the carburization of iron and iron alloys
US2541857A (en) * 1945-05-30 1951-02-13 Leeds & Northrup Co Control of constituent potentials
US2673821A (en) * 1950-11-18 1954-03-30 Midwest Research Inst Heat treatment of steel in a protective atmosphere

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1000215A (fr) * 1949-11-16 1952-02-11 Renault Préparation de gaz pour la cémentation de l'acier

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2161162A (en) * 1938-01-06 1939-06-06 Leeds & Northrup Co Method of carburizing
US2329896A (en) * 1941-01-28 1943-09-21 Leeds & Northrup Co Method of and compound for carburizing
US2541857A (en) * 1945-05-30 1951-02-13 Leeds & Northrup Co Control of constituent potentials
GB629879A (en) * 1947-12-30 1949-09-29 Gen Electric Co Ltd Improvements in or relating to the carburization of iron and iron alloys
US2673821A (en) * 1950-11-18 1954-03-30 Midwest Research Inst Heat treatment of steel in a protective atmosphere

Cited By (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3397875A (en) * 1966-05-20 1968-08-20 Leeds & Northrup Co Apparatus for maintaining a carburizing atmosphere during heat treatment
US3876410A (en) * 1969-12-24 1975-04-08 Ball Brothers Co Inc Method of applying durable lubricous coatings on glass containers
US3970037A (en) * 1972-12-15 1976-07-20 Ppg Industries, Inc. Coating composition vaporizer
US3989004A (en) * 1974-08-15 1976-11-02 Ball Corporation Apparatus for applying durable lubricous coatings to newly formed vitreous surfaces
US4016011A (en) * 1975-04-02 1977-04-05 Kabushiki Kaisha Fujikoshi Method for heat treatment of high alloy steel in a nonexplosive atmosphere
US4154629A (en) * 1975-12-23 1979-05-15 Kabushiki-Kaisha Fujikoshi Process of case hardening martensitic stainless steels
US4183982A (en) * 1977-05-09 1980-01-15 Balzers Aktiengesellschaft Fur Hochvakuumtechnik Und Dunne Schichten Fluid protective wall cover in a vapor deposition chamber
US4145232A (en) * 1977-06-03 1979-03-20 Union Carbide Corporation Process for carburizing steel
US4249965A (en) * 1978-09-19 1981-02-10 Midland-Ross Corporation Method of generating carrier gas
DE2943585A1 (de) * 1979-10-29 1981-04-30 Hollingsworth Gmbh, 7265 Neubulach Verfahren zum erhoehen der haerte und verschleissfestigkeit der oberflaeche eines staehlernen werkstuecks
US4306918A (en) * 1980-04-22 1981-12-22 Air Products And Chemicals, Inc. Process for carburizing ferrous metals
US4317687A (en) * 1980-05-12 1982-03-02 Air Products And Chemicals, Inc. Carburizing process utilizing atmospheres generated from nitrogen-ethanol based mixtures
EP0063655A1 (de) * 1981-04-27 1982-11-03 Air Products And Chemicals, Inc. Verfahren zum Aufkohlen von Eisenmetallen
US4386973A (en) * 1981-05-08 1983-06-07 General Signal Corporation Vacuum carburizing steel
EP0096104A1 (de) * 1982-06-14 1983-12-21 Linde Aktiengesellschaft Verfahren zum Herstellen einer Stickstoff und Wasserstoff enthaltenden Gasatmosphäre
US4632707A (en) * 1985-04-09 1986-12-30 Air Products And Chemicals, Inc. Protective atmosphere process for annealing and/or hardening ferrous metals
FR2623209A1 (fr) * 1987-11-17 1989-05-19 Air Liquide Procede de traitement thermique sous atmosphere gazeuse a base d'azote et d'hydrocarbure
EP0317407A1 (de) * 1987-11-17 1989-05-24 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Verfahren zur Wärmebehandlung in einer Gasatmosphäre auf der Basis von Stickstoff und Kohlenwasserstoff
US4992113A (en) * 1987-11-17 1991-02-12 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process for heat treatment under a gaseous atmosphere containing nitrogen and hydrocarbon
US5186764A (en) * 1990-02-13 1993-02-16 Viscodrive Gmbh Method and apparatus for treating plates with gas
EP0592708A1 (de) * 1991-08-12 1994-04-20 GKN Viscodrive GmbH Verfahren und Vorrichtung zum Behandeln von Platten in einem Gasstrom
US20120325372A1 (en) * 2010-12-17 2012-12-27 Raghavan B Method for reduction of time in a gas carburizing process and cooling apparatus utilizing a high speed quenching oil flow rate
US9365919B2 (en) * 2010-12-17 2016-06-14 Bhagavan Raghavan Method for reduction of time in a gas carburizing process and cooling apparatus utilizing a high speed quenching oil flow rate
CN103276343A (zh) * 2013-06-17 2013-09-04 上海汇森益发工业炉有限公司 多用炉可控气氛渗碳方法

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GB911479A (en) 1962-11-28
BE605100A (fr) 1961-10-16
NL266000A (de)
DE1192486B (de) 1965-05-06
FR1292199A (fr) 1962-04-27
IT649978A (de)
NL126085C (de)
CH404338A (de) 1965-12-15

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