US3802928A - Method for surface hardening steel and cemented carbides - Google Patents
Method for surface hardening steel and cemented carbides Download PDFInfo
- Publication number
- US3802928A US3802928A US00199310A US19931071A US3802928A US 3802928 A US3802928 A US 3802928A US 00199310 A US00199310 A US 00199310A US 19931071 A US19931071 A US 19931071A US 3802928 A US3802928 A US 3802928A
- Authority
- US
- United States
- Prior art keywords
- parts
- weight
- surface hardening
- cemented carbides
- trace amounts
- 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 - Lifetime
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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
-
- 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
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
- C23C30/005—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process on hard metal substrates
-
- 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
-
- 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 employed temperature can be of course increased until reaching the stability limit or boundary, depending upon the type of steel which is to be hardened. In this connection temperatures up to 620 C and l,l50 C respectively can be utilized. Further, the inventive treatment can be carried out with or without the-addition of carbon monoxide or carbon dioxide additives.
- borium carbide brought into contact with a mixture containing approximately 5 70 parts by weight borium carbide, 1 60 parts by weights anhydrous aluminum oxide, trace amounts up to 6 parts by weight NaBF and trace amounts up to 10 parts by weight sodium floride.
- the present invention improves upon the surface hardening technique disclosed in my aforementioned copending United States application. More specifically,
- High temperature hardeners such as for instance high-speed'steels' require for an additional boundary or rim hardening suitable carrier structures, such as for instance austenitic core structures.
- suitable boundary hardening techniques must therefore be sufficiently effective at relatively low temperatures in the order of approximately 580 C 620 C in order to be ableto carry out tempering treatments without core hardness damage.
- the more recent techniques for steel boriding are to a certain extent superior to the known techniques for nitride hardening, yet requireoperatingtemperatures between approximately 700 C and 900 C.
- the inventive method brings about a multiple time reduction in the furnace throughput. There is also simultaneously brought about a pronounced increase in the infusion depth.
- the resulting hard film or coating A preferred mixture possesses for instance the j following composition:
- a COMO-310-high speed steel with a performance hardness of 950 HV is heat treated for 5 minutes at a temperature in a range between 400 C and 440 C with the above composition of hardening agent while introducing ammonia gas. Even with this intentionally brief selected treatment-time the external steelhardness climbed to a value exceeding 3,700 HV.
- the infusion depth after 5 minutes was 500 microns. After 10 minutes there was' obtained approximately 1,000 microns infusion depth.
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)
Abstract
A method of surface hardening materials, especially steel and cemented carbides, wherein the material to be treated while extensively excluding oxygen is brought into contact with a mixture containing approximately 5 - 70 parts by weight borium carbide, 1 - 60 parts by weight anhydrous aluminum oxide, trace amounts up to 6 parts by weight NaBF4 and trace amounts up to 10 parts by weight sodium floride. According to the invention ammonia gas is introduced during treatment temperatures exceeding approximately 400* C.
Description
United States Patent 1191 Bopp, deceased I METHOD FOR SURFACE HARDENING STEEL AND CEMENTED CARBIDES Anton Bopp, deceased, late of Dorfstrasse 198, Meilen,
1 Switzerland by Martha Bopp, sole heir Inventor:
Filed: Nov. 16, 1971 Appl. No: 199,310 1 Foreign Application Priority Data Nov. 20, 1970 Switzerland 17283/70 US. Cl. 148/6, 148/635 Int. Cl...; C23c 11/16 Field of Search 148/63, 6.35, 16.6, 6;
117/106 C, 106 R, 107.2 R, 107.2 P, 107
References Cited UNITED STATES PATENTS 9/1958 Low l48/l6.6
ll/l971 Pike 1 ll7/107.2P 4/1962 Samuel et al. 148/63 Kunst....
[ 51 Apr. 9, 1974 3,090,702 5/1963 Commanday @1211. 117/1072 P 3,286,684 1l/1966 Aves 117/1072 P FOREIGN PATENTS OR APPLICATIONS 743,643 1/1956 Great Britain 148/63 Primary Examiner-Alfred L. Leavitt Assistant E.\'aminerCa1eb Weston Attorney, Agent, or FirmMolinare, Allegretti, Newitt and Witcoff [57 ABSTRACT 2 Claims, No Drawings METHOD FOR SURFACE HARDENING STEEL AND CEMENTED CARBIDES BACKGROUND OF THE INVENTION there is taught a technique wherein the material undergoing treatment, at a temperature above approximately hard metals or cemented carbides. The steels can be treated while in a'finished shaped condition without distortion and without embrittlement, the external appearance remaining practically unchanged.
The employed temperature can be of course increased until reaching the stability limit or boundary, depending upon the type of steel which is to be hardened. In this connection temperatures up to 620 C and l,l50 C respectively can be utilized. Further, the inventive treatment can be carried out with or without the-addition of carbon monoxide or carbon dioxide additives.
- Regarding the mixture with which the material to be treated is brought into contact such has been disclosed in my previously mentioned, copending United States application, Ser, No. 165,948, and the considerations explained therein are'also here applicable. Although 570 C, and while extensively excluding oxygen,,is
brought into contact with a mixture containing approximately 5 70 parts by weight borium carbide, 1 60 parts by weights anhydrous aluminum oxide, trace amounts up to 6 parts by weight NaBF and trace amounts up to 10 parts by weight sodium floride.
The present invention improves upon the surface hardening technique disclosed in my aforementioned copending United States application. More specifically,
it has been found that the treatment temperatures can be further reduced if during the thermal treatment there is simultaneously introduced ammonia.
The hardening of steels by treatment in an ammonia gas stream is known in the art, however the previously known procedures are only applicable to particular alloy or special steels capable of undergoing nitration. However, hardness values exceeding 900 are generally never reached, usually only 600 800 HV (Vickers hardness test), which are considerably below those attainable when practicing the teachings of the present invention.
During a roughly carried out comparative test a steel sample was gas-nitrided according to conventional techniques for hours, whereas'whe n working with the treatment can be carried 'out as described in my previously mentioned application, it is considerably more advantageous in this instance if the material to be hardened is arranged in a gas chamber, that is to say, there is utilized for instance a conventional gas nitrid-' ing furnace while employing standard operating conditions and there is introduced into such without contact with the steel the necessary hardening powder. Therequirements per square meter of steel surface for obtaining a 100 micron infusion layer or film is in the order of 3.5 to 15 grams powder. With multiple use of the powder the process uses an excess amount thereof and simultaneously there is prevented deficiencies in the infusion hard material or layer by flushing with ammothe inventive method in approximately one-tenththe' time there was obtained a considerably greater infusion depth and more than twice the hardness.
High temperature hardeners, such as for instance high-speed'steels' require for an additional boundary or rim hardening suitable carrier structures, such as for instance austenitic core structures. Suitable boundary hardening techniques must therefore be sufficiently effective at relatively low temperatures in the order of approximately 580 C 620 C in order to be ableto carry out tempering treatments without core hardness damage. I The more recent techniques for steel boriding are to a certain extent superior to the known techniques for nitride hardening, yet requireoperatingtemperatures between approximately 700 C and 900 C.
Therefore, it should be recognized that aconsiderable advance in the art is realized if it is possible to nia and b'y resorption in the furnace.
The inventive method brings about a multiple time reduction in the furnace throughput. There is also simultaneously brought about a pronounced increase in the infusion depth. The resulting hard film or coating A preferred mixture possesses for instance the j following composition:
B C 50 parts by weight Aluminum oxide. 43 parts by weight Carbon black- ,2 parts by weight NaBF 2 parts by weight NaF 3 parts by weight EXEMPYLAIRY EMBODIMENT .01 THE INVENTION;
A COMO-310-high speed steel with a performance hardness of 950 HV is heat treated for 5 minutes at a temperature in a range between 400 C and 440 C with the above composition of hardening agent while introducing ammonia gas. Even with this intentionally brief selected treatment-time the external steelhardness climbed to a value exceeding 3,700 HV. The infusion depth after 5 minutes was 500 microns. After 10 minutes there was' obtained approximately 1,000 microns infusion depth. t
From the above it will be recognized that the inventive technique, both with regard to the hardening effect as well as also with regard to the employed operating temperature, is considerably superior to the heretofore known prior art techniques. Furthermore, the inventive What is claimed is:
l. A method of surface hardening materials by a boriding and nitriding process, especially steel and cemented carbides, wherein the material to be treated while extensively excluding oxygen is brought into contact with a mixture containing approximately 5-70 parts by weight borium carbide, 1-60 parts by weight anhydrous aluminum oxide, trace amounts up to 6 parts by Weight NaBF and trace amounts up to 10 parts by weight sodium floride, the improvement com-- prising introducing ammonia gas during a treatment temperature in a range exceeding approximately 400 C up to approximately 620 C. i
2. The methodas defined in claim 1, including the step of furtherintroducing an additive selected from carbon monoxide and carbon dioxide and mixtures thereof.
Claims (1)
- 2. The method as defined in claim 1, including the step of further introducing an additive selected from carbon monoxide and carbon dioxide and mixtures thereof.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CH1728370 | 1970-11-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3802928A true US3802928A (en) | 1974-04-09 |
Family
ID=4424195
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US00199310A Expired - Lifetime US3802928A (en) | 1970-11-20 | 1971-11-16 | Method for surface hardening steel and cemented carbides |
Country Status (4)
Country | Link |
---|---|
US (1) | US3802928A (en) |
DE (1) | DE2155797A1 (en) |
FR (1) | FR2115288A6 (en) |
GB (1) | GB1377098A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1983000106A1 (en) * | 1981-07-02 | 1983-01-20 | Turbine Metal Technology Inc | Erosion resistant tubular apparatus for handling slurries |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1555802A (en) * | 1976-01-28 | 1979-11-14 | Atomic Energy Authority Uk | Metalworking tool elements |
-
1971
- 1971-11-10 DE DE19712155797 patent/DE2155797A1/en active Pending
- 1971-11-12 GB GB5258671A patent/GB1377098A/en not_active Expired
- 1971-11-16 US US00199310A patent/US3802928A/en not_active Expired - Lifetime
- 1971-11-19 FR FR7141529A patent/FR2115288A6/fr not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1983000106A1 (en) * | 1981-07-02 | 1983-01-20 | Turbine Metal Technology Inc | Erosion resistant tubular apparatus for handling slurries |
US4389439A (en) * | 1981-07-02 | 1983-06-21 | Turbine Metal Technology, Inc. | Erosion resistant tubular apparatus for handling slurries |
Also Published As
Publication number | Publication date |
---|---|
GB1377098A (en) | 1974-12-11 |
DE2155797A1 (en) | 1972-05-25 |
FR2115288A6 (en) | 1972-07-07 |
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