GB1586348A - Process for the production of a protective gas - Google Patents
Process for the production of a protective gas Download PDFInfo
- Publication number
- GB1586348A GB1586348A GB22439/78A GB2243978A GB1586348A GB 1586348 A GB1586348 A GB 1586348A GB 22439/78 A GB22439/78 A GB 22439/78A GB 2243978 A GB2243978 A GB 2243978A GB 1586348 A GB1586348 A GB 1586348A
- Authority
- GB
- United Kingdom
- Prior art keywords
- liquid
- protective gas
- gas mixture
- production
- hydrocarbon
- 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
Links
- 230000001681 protective effect Effects 0.000 title claims description 29
- 238000000034 method Methods 0.000 title claims description 26
- 238000004519 manufacturing process Methods 0.000 title claims description 19
- 239000007789 gas Substances 0.000 claims description 57
- 239000000203 mixture Substances 0.000 claims description 48
- 239000007788 liquid Substances 0.000 claims description 32
- 229930195733 hydrocarbon Natural products 0.000 claims description 22
- 150000002430 hydrocarbons Chemical class 0.000 claims description 22
- 239000004215 Carbon black (E152) Substances 0.000 claims description 20
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 19
- 239000001301 oxygen Substances 0.000 claims description 19
- 229910052760 oxygen Inorganic materials 0.000 claims description 19
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 18
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims description 16
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 16
- 238000010438 heat treatment Methods 0.000 claims description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 10
- 229910052799 carbon Inorganic materials 0.000 claims description 10
- 229910052751 metal Inorganic materials 0.000 claims description 10
- 239000002184 metal Substances 0.000 claims description 10
- 229910052757 nitrogen Inorganic materials 0.000 claims description 9
- 229910052786 argon Inorganic materials 0.000 claims description 8
- -1 ferrous metals Chemical class 0.000 claims description 8
- 238000001704 evaporation Methods 0.000 claims description 6
- 239000012159 carrier gas Substances 0.000 claims description 5
- 230000008020 evaporation Effects 0.000 claims description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 claims description 4
- CWYNVVGOOAEACU-UHFFFAOYSA-N Fe2+ Chemical compound [Fe+2] CWYNVVGOOAEACU-UHFFFAOYSA-N 0.000 claims description 2
- 239000003570 air Substances 0.000 claims description 2
- 238000012544 monitoring process Methods 0.000 claims description 2
- 239000001294 propane Substances 0.000 claims description 2
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000002485 combustion reaction Methods 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 238000007792 addition Methods 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 239000008246 gaseous mixture Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
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
- C21D1/76—Adjusting the composition of the atmosphere
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Furnace Details (AREA)
- Solid-Phase Diffusion Into Metallic Material Surfaces (AREA)
- Hydrogen, Water And Hydrids (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
- Solid-Sorbent Or Filter-Aiding Compositions (AREA)
- Gas Separation By Absorption (AREA)
Description
(54) PROCESS FOR THE PRODUCTION OF A PROTECTIVE GAS
(71) We, MESSER GRIESHEIM GmbH., of Hanauer Landstrasse, 330, 6000 Frankfurt/
Main, Federal Republic of Germany, a
Joint-Stock Company organised under the laws of the Federal Republic of Germany, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The present invention is concerned with a process for the production of a protective gas for the heat treatment of ferrous metals in a furnace.
Protective gas with a definite carbonising action for the heat treatment of ferrous metals consists essentially of a carrier gas, the
so-called endogas, and a hydrocarbon for the adjustment of the carbon potential. Such an endogas consists, for example, of nitrogen, hydrogen, carbon monoxide and carbon
dioxide. It can be produced by partial combustion in a protective gas producer (endothermal gas generator). The partial combustion is maintained by the external supply of heat. With the help of these protective gases, the surface of ferrous metals is hardened by
the incorporation of carbon.
The production of these protective gas mixtures in endogas generators is comparatively laborious. The generators themselves
are expensive and require space and, in addi
tion, the amount of protective gas produced in an endogas generator can only be slightly
varied.
In order to avoid these disadvantages,
according to German Patent Specification
No. 2,450,879, the individual components of the protective gas mixtures are mixed to
gether and subjected to an increased temperature, a chemical reaction hereby taking
place between the components of the mixture,
this chemical reaction at an elevated tem
perature taking place in the furnace.
This process admittedly avoids the use of
expensive endogas generators but necessitates
a high expenditure for the gas mixing
apparatus. Since the inert carrier gas forms,
in any case, the main amount of the gas
mixture and the oxygen carrier and the hydrocarbon gas must, in some cases, only be present in amounts of a few tens of percentage in the mixture, this requires a high expense for the exactitude of regulation of the mixing apparatus.
Disturbances of the mixing apparatus cannot be excluded. Such disturbances can, in addition, be very expensive since, inter alia, the total charge of a furnace can be ruined by a heat treatment with a protective gas which has not got the correct composition. Furthermore, three different storage devices are necessary for the three components.
Therefore, it is an object of the present invention to provide a process for the production of a protective gas for the heat treatment of ferrous metals in a furnace, consisting of nitrogen and/or argon, oxygen and/or air and a hydrocarbon which needs neither expensive endogas generators not a laborious and disturbance-prone gas mixing device and, furthermore, does not require any great expense for the storage means for the gases.
According to the present invention, this is achieved in that a liquid gas mixture is produced by mixing and dissolving a hydrocarbon and oxygen and/or air in liquid argon and/or nitrogen and temporarily stored, whereafter it is evaporated and passed into the furnace.
The main component of the gas mixture is the inert carrier gas, i.e. nitrogen or argon.
Preferred liquid gas mixtures contain 0-1 to 25% by weight of methane and 0 1 to 10% by weight of oxygen. The hydrocarbon is preferably methane since the vapour pressure curve of methane does not differ very much from the vapour pressure curves of nitrogen, argon and oxygen. For this reason, when evaporating a liquid gas mixture in which the hydrocarbon is methane, only a slight demixing takes place. Therefore, a greater part of the liquid gas mixture can be evaporated without the composition of the gaseous mixture obtained by evaporation changing substantially.
Consequently, depending upon the composition of the liquid gas mixture, there is obtained a gas mixture of quite definite composition.
The liquid mixture can be produced without difficulties and with a high degree of exactitude, for example, by simply weighting out the liquid components in the manner described in German Patent Specification No.
2,435,026. In contradistinction to the process described in this German Patent Specification for the production of a protective gas with a definite carbonising action, the protective gas according to the present invention contains oxygen or air as additional component in the liquid mixture. The presence of oxygen makes possible a simpler regulation of the carbon potential.
In some cases, the protective gas obtained by the evaporation of the liquid mixture will not correspond to the composition required for the heat treatment of a particular ferrous metal. This is especially the case when the carbon potential is to be changed during the heat treatment. This can take place in a simple manner by admixing gaseous oxygen, air or hydrocarbon. The gaseous admixed hydrocarbon need not be the same as the hydrocarbon present in the liquid gas mixtures. When, for example, methane is present on the liquid gas mixture, the gaseous hydrocarbon admixed therewith can be propane.
This admixing does not give rise to any problems whatsoever with regard to the degree of exactitude which is to be maintained: for this purpose, there are available known atmosphere regulators for the regulation of the carbon potential.
In most cases of use, it is, therefore, possible, by means of the process according to the present invention, to regard the protective gas produced as a synthetic endogas which can be employed as carrier gas for hardening process in the case of the simultaneous supplying of hydrocarbons.
In comparison with the previously known processes for the production of a protective gas comprised of these components for the heat treatment of ferrous metals, the process according to the present invention offers considerable advantages with regard to production, storage and transport. The device for the storage of the liquid mixture and for the evaporation thereof needs very little space. In contradistinction to the known processes, the user is no longer burdened with the production of the gas mixture and with the monitoring of the exactitude of the mixing. Consequently, skilled personnel can be saved. In comparison with the production in endogas generators, the amount of gaseous protective gas produced can be adapted very flexibly to the actual requirements.
WHAT WE CLAIM IS:
1. Process for the production of a protective gas mixture for the heat treatment of ferrous metals in a furnace, consisting of nitrogen and/or argon, oxygen and/or air and a hydrocarbon, wherein a liquid gas mixture is produced by premixing and dissolving the hydrocarbon and the oxygen and/or the air in liquid argon and/or nitrogen and temporarily stored, whereafter it is evaporated and passed into the furnace.
2. Process according to claim 1, wherein, for the regulation of the carbon potential, oxygen, air or a hydrocarbon is additionally passed in a gaseous state into the furnace.
3. Process according to claim 1 for the production of a protective gas mixture substantially as hereinbefore described.
4. A protection gas mixture whenever produced by the process according to claim 1.
5. A protective gas mixture according to claim 4, whenever in liquid form.
6. A liquid gas mixture according to claim 5, which contains 01 to 25% by weight of methane.
7. A liquid gas mixture according to claim 5 or 6, which contains 0-1 to 10% by weight of oxygen.
8. A liquid gas mixture according to any of claims 5 to 7, substantially as herein before described.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (8)
1. Process for the production of a protective gas mixture for the heat treatment of ferrous metals in a furnace, consisting of nitrogen and/or argon, oxygen and/or air and a hydrocarbon, wherein a liquid gas mixture is produced by premixing and dissolving the hydrocarbon and the oxygen and/or the air in liquid argon and/or nitrogen and temporarily stored, whereafter it is evaporated and passed into the furnace.
2. Process according to claim 1, wherein, for the regulation of the carbon potential, oxygen, air or a hydrocarbon is additionally passed in a gaseous state into the furnace.
3. Process according to claim 1 for the production of a protective gas mixture substantially as hereinbefore described.
4. A protection gas mixture whenever produced by the process according to claim 1.
5. A protective gas mixture according to claim 4, whenever in liquid form.
6. A liquid gas mixture according to claim 5, which contains 01 to 25% by weight of methane.
7. A liquid gas mixture according to claim 5 or 6, which contains 0-1 to 10% by weight of oxygen.
8. A liquid gas mixture according to any of claims 5 to 7, substantially as herein before described.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2737610A DE2737610C2 (en) | 1977-08-20 | 1977-08-20 | Process for the production of a protective gas for the heat treatment of ferrous metals |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1586348A true GB1586348A (en) | 1981-03-18 |
Family
ID=6016891
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB22439/78A Expired GB1586348A (en) | 1977-08-20 | 1978-05-25 | Process for the production of a protective gas |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS5443110A (en) |
| AT (1) | AT364884B (en) |
| BE (1) | BE869412A (en) |
| DE (1) | DE2737610C2 (en) |
| ES (1) | ES472283A1 (en) |
| FR (1) | FR2400560A1 (en) |
| GB (1) | GB1586348A (en) |
| IT (1) | IT1098016B (en) |
| NL (1) | NL7808414A (en) |
| ZA (1) | ZA784695B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2507898Y2 (en) * | 1989-11-22 | 1996-08-21 | 株式会社東洋精機製作所 | Temperature controller for constant temperature bath |
| JP7407495B2 (en) * | 2021-10-29 | 2024-01-04 | 関東冶金工業株式会社 | Heat treatment furnace and heat treatment method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2435026A1 (en) * | 1974-07-20 | 1976-02-05 | Messer Griesheim Gmbh | PROCESS FOR PRODUCING A PROTECTIVE GAS WITH DEFINED CARBON EFFECT |
-
1977
- 1977-08-20 DE DE2737610A patent/DE2737610C2/en not_active Expired
-
1978
- 1978-05-25 GB GB22439/78A patent/GB1586348A/en not_active Expired
- 1978-07-24 AT AT0537678A patent/AT364884B/en not_active IP Right Cessation
- 1978-07-31 BE BE189621A patent/BE869412A/en not_active IP Right Cessation
- 1978-08-01 FR FR7822694A patent/FR2400560A1/en active Granted
- 1978-08-02 ES ES472283A patent/ES472283A1/en not_active Expired
- 1978-08-08 IT IT26575/78A patent/IT1098016B/en active
- 1978-08-11 NL NL7808414A patent/NL7808414A/en not_active Application Discontinuation
- 1978-08-15 JP JP9944078A patent/JPS5443110A/en active Pending
- 1978-08-18 ZA ZA00784695A patent/ZA784695B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ZA784695B (en) | 1979-08-29 |
| JPS5443110A (en) | 1979-04-05 |
| DE2737610C2 (en) | 1983-10-27 |
| BE869412A (en) | 1978-11-16 |
| DE2737610A1 (en) | 1979-03-01 |
| IT1098016B (en) | 1985-08-31 |
| NL7808414A (en) | 1979-02-22 |
| ES472283A1 (en) | 1979-02-16 |
| FR2400560A1 (en) | 1979-03-16 |
| ATA537678A (en) | 1981-04-15 |
| FR2400560B3 (en) | 1981-03-06 |
| AT364884B (en) | 1981-11-25 |
| IT7826575A0 (en) | 1978-08-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| PCNP | Patent ceased through non-payment of renewal fee |