MXPA98000770A - Process for heat treatment of metal parts based on iron in an active atmosphere with high potential of carb - Google Patents
Process for heat treatment of metal parts based on iron in an active atmosphere with high potential of carbInfo
- Publication number
- MXPA98000770A MXPA98000770A MXPA/A/1998/000770A MX9800770A MXPA98000770A MX PA98000770 A MXPA98000770 A MX PA98000770A MX 9800770 A MX9800770 A MX 9800770A MX PA98000770 A MXPA98000770 A MX PA98000770A
- Authority
- MX
- Mexico
- Prior art keywords
- oxidant
- volume
- atmosphere
- oxygen
- reaction
- Prior art date
Links
- 238000000034 method Methods 0.000 title claims abstract description 25
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 title claims abstract description 12
- 238000010438 heat treatment Methods 0.000 title claims abstract description 10
- 229910052742 iron Inorganic materials 0.000 title claims abstract description 6
- 229910052751 metal Inorganic materials 0.000 title claims description 5
- 239000002184 metal Substances 0.000 title claims description 5
- 239000007800 oxidant agent Substances 0.000 claims abstract description 22
- 230000001590 oxidative Effects 0.000 claims abstract description 21
- 239000001301 oxygen Substances 0.000 claims abstract description 18
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 18
- MYMOFIZGZYHOMD-UHFFFAOYSA-N oxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims abstract description 18
- OKTJSMMVPCPJKN-UHFFFAOYSA-N carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 10
- 239000000446 fuel Substances 0.000 claims abstract description 7
- 239000003638 reducing agent Substances 0.000 claims abstract description 5
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract 5
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract 5
- 238000006555 catalytic reaction Methods 0.000 claims abstract 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 14
- 239000003054 catalyst Substances 0.000 claims description 10
- 239000003345 natural gas Substances 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 8
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 8
- 238000003860 storage Methods 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 7
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Chemical compound [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N AI2O3 Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 4
- 229910052697 platinum Inorganic materials 0.000 claims description 4
- 239000005092 Ruthenium Substances 0.000 claims description 3
- MCMNRKCIXSYSNV-UHFFFAOYSA-N ZrO2 Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 3
- 239000000919 ceramic Substances 0.000 claims description 3
- 238000011065 in-situ storage Methods 0.000 claims description 3
- 238000001764 infiltration Methods 0.000 claims description 3
- 239000000395 magnesium oxide Substances 0.000 claims description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 3
- 229910052762 osmium Inorganic materials 0.000 claims description 3
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 claims description 3
- 229910052763 palladium Inorganic materials 0.000 claims description 3
- 239000010970 precious metal Substances 0.000 claims description 3
- 238000010992 reflux Methods 0.000 claims description 3
- KJTLSVCANCCWHF-UHFFFAOYSA-N ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims description 3
- 229910052707 ruthenium Inorganic materials 0.000 claims description 3
- 238000000926 separation method Methods 0.000 claims description 3
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- JPJZHBHNQJPGSG-UHFFFAOYSA-N titanium;zirconium;tetrahydrate Chemical compound O.O.O.O.[Ti].[Zr] JPJZHBHNQJPGSG-UHFFFAOYSA-N 0.000 claims description 3
- 229910001928 zirconium oxide Inorganic materials 0.000 claims description 3
- 229910000480 nickel oxide Inorganic materials 0.000 claims 2
- GNRSAWUEBMWBQH-UHFFFAOYSA-N oxonickel Chemical group [Ni]=O GNRSAWUEBMWBQH-UHFFFAOYSA-N 0.000 claims 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 8
- 229910002091 carbon monoxide Inorganic materials 0.000 description 8
- 229910000831 Steel Inorganic materials 0.000 description 7
- 239000010959 steel Substances 0.000 description 7
- 238000011068 load Methods 0.000 description 6
- 238000005256 carbonitriding Methods 0.000 description 5
- 238000005255 carburizing Methods 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 241000894007 species Species 0.000 description 5
- 238000002485 combustion reaction Methods 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000001569 carbon dioxide Substances 0.000 description 3
- 238000010494 dissociation reaction Methods 0.000 description 3
- 230000005593 dissociations Effects 0.000 description 3
- 239000001257 hydrogen Substances 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- 229910052739 hydrogen Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000005755 formation reaction Methods 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000005121 nitriding Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 125000003158 alcohol group Chemical group 0.000 description 1
- 150000001298 alcohols Chemical class 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- 238000007084 catalytic combustion reaction Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000003247 decreasing Effects 0.000 description 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- -1 methanol Chemical compound 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 230000001737 promoting Effects 0.000 description 1
Abstract
A process for the heat treatment of metallic parts based on iron in an active atmosphere with a high carbon potential, characterized in that this atmosphere is obtained by the catalytic reaction between a hydrocarbon fuel and an oxidant having a content of oxygen greater than 21% by volume, and that said atmosphere contains at least 60% by volume of cementitious and / or reducing agents. Preferably, the oxidant has an oxygen content between 21% and 35% by volume
Description
PROCESS FOR HEAT TREATMENT OF METAL PARTS BASED ON IRON IN AN ACTIVE ATMOSPHERE WITH
HIGH CARBON POTENTIAL
FIELD OF THE INVENTION
This invention relates to a process for the heat treatment of metal parts based on iron in an active atmosphere with a high carbon potential, which makes it possible to increase the carbon content of the metal parts. Treatments for this type of problem include cementation and carbonitriding.
BACKGROUND OF THE INVENTION
It is already known how to produce atmospheres with a high carbon potential by means of thermal dissociation of alcohols, particularly methanol. This dissociation determines the formation of a reducing species, such as hydrogen and, of a species that is cementing as well as reducing, such as carbon monoxide. If it is necessary to obtain certain concentration values, these species can eventually be diluted with nitrogen from a cryogenic storage tank. However, this known process for the production of a heat treatment atmosphere with a high carbon content involves certain disadvantages.
On the one hand, in fact, the amounts of carbon monoxide obtained are in a fixed ratio that is determined by the atomic composition of the alcohol used, and therefore this may be unsuitable for certain types of treatment. On the other hand the use of the raw material as an alcohol, particularly methanol, involves intrinsic problems of high cost and safety considerations.
BRIEF DESCRIPTION OF THE INVENTION
The raw materials used to generate a treatment atmosphere in accordance with the invention are readily available at a reasonable cost and do not present a particular security risk. In fact and in particular, it is possible to use natural gas or methane as fuel. In addition, by properly adjusting the ratio between the fuel and the oxidant, and the oxygen content of the oxidant, it is possible to obtain a wide range of treatment atmosphere compositions usable for most of the various requirements. In particular, by increasing the oxygen content of the oxidant to 100% and correspondingly reducing the content of inert materials, especially nitrogen, it is possible to obtain 100% cementing and / or reducing agents, such as hydrogen and carbon monoxide in the atmosphere of treatment.
Furthermore, by reducing the content of the inert materials it is possible to reach a higher temperature during the combustion reaction. This provides the additional advantage of promoting the formation of desired materials, such as hydrogen and carbon monoxide, with respect to completely oxidized undesirable materials such as water and carbon dioxide. The catalytic combustion reaction can be conducted without distinction either in a reactor separated from the chamber in which the heat treatment is carried out or in a reactor contained therein. Preferably, the oxygen content of the oxidizer is included between 21% and 35% by volume. This oxidant can, for example, be obtained from the reflux of in situ plants that serve for the separation of air by means of infiltration and absorption or, by mixing natural air with oxygen entering from pressurized or cryogenic storage tanks, or by mixing Nitrogen and oxygen entering from pressure or cryogenic storage. The reaction is carried out at a temperature preferably included between 400 ° C and 1100 ° C and, especially between 750 ° C and 1050 ° C. As a catalyst for the combustion reaction, use can be made of all types of catalysts known in the art for this type of reaction. For example, a catalyst supported on a refractory support based on oxide of
nickel or precious metals such as platinum, osmium, palladium and ruthenium or their oxides. This refractory support can be of the ceramic type and preferably based on alumina, silica, zirconium oxide, titanium oxide or magnesium oxide. This invention is now described in greater detail based on the following examples given without limitation.
EXAMPLE 1- Carbocementation A combustion reactor is placed outside a pit-type furnace in which the heat treatment of carburizing takes place. The reactor uses a catalyst system consisting of 1% platinum as a catalyst on an alumina support. The reactor is fed with a mixture of natural gas and oxidant that comes from a pressurized bottle and with an oxygen content equivalent to 33% by volume of nitrogen. The oxidant / natural gas ratio is equal to 1.5. the reaction carried out at a temperature of 930 ° C produces an atmosphere containing 73% reducing agents (hydrogen and carbon monoxide), 24.5% cementing species (carbon monoxide) and 0.16% carbon dioxide and a point of -3 ° C condensation. This atmosphere is injected into the pit-type furnace in which a fixation temperature of 920 ° C is maintained to carry out the carburizing of a steel load. In this way, a carbon potential equivalent to 1% is obtained. If necessary, this
Potential can be increased or decreased during the cementing treatment by injecting natural gas or air respectively directly into the furnace. The time required to carry out the carburizing of a steel load (16MnCr5), which requires an effective depth (hardness 525 HV) of 0.5 - 0.6 mm, is approximately 1 hour and 30 minutes. The time required to carry out the carburizing of a steel load (18NiCrMo5), which requires an effective depth of 1 mm, is approximately 3 hours. The time required to carry out the carburizing of a steel load (20MnCr5), which requires an effective depth of 1.4 mm, is approximately 4 hours and 15 minutes.
EXAMPLE 2 - Carbonitriding The combustion reactor is placed outside a chamber furnace in which the heat treatment is carried out by carbonitriding. A catalyst system similar to that of Example 1 is used in the reactor. The reactor is fed with a mixture of natural gas and oxidant with an oxygen content equivalent to 31% by volume in nitrogen. The oxidant is obtained by enriching the compressed air of the plant with oxygen from a cryogenic storage tank. The oxidant / natural gas ratio is equivalent to 1.6. The reaction, conducted at a temperature of 930 ° C, produces an atmosphere containing 70%
of reducing materials (hydrogen and carbon monoxide), 23.5% of cementing species (carbon monoxide) and 0.15% of carbon dioxide, with a dew point of -4 ° C. This atmosphere is injected into the chamber furnace which is set for an operating temperature of 860 ° C for the purpose of cementing a steel charge in a first phase. A carbon potential equivalent to 0.9% is thus obtained. if necessary, this potential can be increased or reduced during cementing treatment by means of direct injection into the furnace, either natural gas or air. Subsequently, a nitriding phase is carried out by injecting within the furnace, by a method known in the art, ammonia in various degrees of dissociation to control the nitriding potential. The time required to carry out the carbonitriding of a C10 steel load, for which an effective depth (hardness 525 HV) is 0.2 mm, is approximately 1 hour. The time required to carry out the carbonitriding of a C10 steel load, for which an effective depth is 0.5 mm, is about 2 hours. It goes without saying that, considering the principle of the invention, the details of execution and the modality can vary widely from what has been described above without departing from the scope of this invention.
Claims (18)
1. A process for the heat treatment of metal parts based on iron in an active atmosphere that has a high carbon potential, the process involves obtaining said atmosphere through the catalytic reaction between a hydrocarbon fuel and an oxidant having an oxygen content greater than 21% by volume, and containing at least 60% by volume of cementitious and / or reducing agents.
2. The process of claim 1, wherein the oxidant has an oxygen content between 21% and 35% by volume.
3. The process of claim 1, wherein the oxidant is obtained from the reflux of the air separation systems in situ through infiltration and adsorption.
4. The process of claim 1, wherein the oxidant is obtained by mixing natural air with oxygen entering from pressurized or cryogenic storage tanks.
The process of claim 1, wherein the oxidant is obtained by mixing nitrogen and the oxygen that enters from the pressurized or cryogenic storage tanks.
6. The process of claim 1, wherein the hydrocarbon fuel is natural gas or methane.
The process of claim 1, wherein the reaction is carried out at a temperature included between 400 ° C and 1100 ° C and, preferably between 750 ° C and 1050 ° C.
8. The process of claim 1, wherein the reaction is carried out in the presence of a supported catalyst on a refractory support 9.
The process of claim 8, wherein the catalyst is a nickel oxide or a precious metal selected from the group which consists of platinum, osmium, palladium and ruthenium or their oxides.
The process of claim 8, wherein the refractory support is of the ceramic type selected from the group consisting of alumina, silica, zirconium oxide, titanium oxide and magnesium oxide.
The process of claim 2, wherein the oxidant is obtained from the reflux of the air separation systems in situ through infiltration and adsorption.
The process of claim 2, wherein the oxidant is obtained by mixing natural air with oxygen entering from pressurized or cryogenic storage tanks.
The process of claim 2, wherein the oxidant is obtained by mixing nitrogen and the oxygen entering from the pressurized or cryogenic storage tanks.
The process of claim 2, wherein the hydrocarbon fuel is natural gas or methane.
15. The process of claim 2, wherein the reaction is carried out at a temperature included between 400 ° C and 1100 ° C and, preferably between 750 ° C and 1050 ° C.
16. The process of claim 2, wherein the reaction is carried out in the presence of a supported catalyst on a refractory support
17. The process of claim 16, wherein the catalyst is a nickel oxide or a precious metal selected from the group which consists of platinum, osmium, palladium and ruthenium or their oxides. The process of claim 16, wherein the refractory support is of the ceramic type selected from the group consisting of alumina, silica, zirconium oxide, titanium oxide and magnesium oxide. SUMMARY A process for the heat treatment of metallic parts based on iron in an active atmosphere with a high carbon potential, characterized in that this atmosphere is obtained by the catalytic reaction between a hydrocarbon fuel and an oxidant having a content of oxygen greater than 21% by volume, and that said atmosphere contains at least 60% by volume of cementitious and / or reducing agents. Preferably, the oxidant has an oxygen content between 21% and 35% by volume.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| TOTO97A000065 | 1997-01-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| MXPA98000770A true MXPA98000770A (en) | 2000-01-01 |
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