Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C32/00—Non-ferrous alloys containing at least 5% by weight but less than 50% by weight of oxides, carbides, borides, nitrides, silicides or other metal compounds, e.g. oxynitrides, sulfides, whether added as such or formed in situ
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/90—Carbides
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
  • C01B32/00—Carbon; Compounds thereof
  • C01B32/90—Carbides
  • C01B32/914—Carbides of single elements
• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
  • C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
  • C21C7/04—Removing impurities by adding a treating agent
  • C21C7/076—Use of slags or fluxes as treating agents
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/20—Obtaining niobium, tantalum or vanadium
  • C22B34/22—Obtaining vanadium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
  • C22B34/00—Obtaining refractory metals
  • C22B34/30—Obtaining chromium, molybdenum or tungsten
  • C22B34/34—Obtaining molybdenum
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C33/00—Making ferrous alloys
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/10—Solid density
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/80—Compositional purity
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P10/00—Technologies related to metal processing
  • Y02P10/20—Recycling

Definitions

• the present invention relates to a vanadium containing addition agent for use in the treating of steel. More particularly, the present invention relates to a vanadium and carbon containing addition agent in which the predominant proportion of combined vanadium is in the form of V C. That is, more vanadium is combined as V C than as VC.
• vanadium In the manufacture of tool steels and other steels such as the high strength, low alloy structural steels, and the normal constructional steels, significant amounts of vanadium are utilized as an alloying constituent in order to provide improvement in the properties of the steel.
• vanadium additions are widely used to provide toughness and strength, and also to aid in stabilizing steels.
• the amount of vanadium used for this purpose is significantly increasing.
• ferrovanadium for use as an alloy addition
• ferrovanadium which generally contains about 50 to 75% V, 0.2 to 3.0% C, 1.5% to 8.00% Si, remainder iron.
• the present commercial production of ferrovanadium generally involves the aluminothermic reduction of vanadium oxides and this type of processing generally results in a relatively high price for the resulting product.
• vanadium carbide In place of ferrovanadium, vanadium carbide, VC, has been proposed as an addition agent for treating steel.
• vanadium carbide, VC has a comparatively slow solubility in molten steel and this feature, together with the relatively low proportion of contained vanadium and the relatively low strength of the material have precluded the commercial utilization of vanadium carbide as an addition agent in spite of its reduced cost.
• a vanadium-containing addition agent in accordance with the present invention is the solid state reaction product of a pressed mixture of carbon and vanadium oxide in which reaction product the predominant proportion of combined vanadium is in the form of V C and in which the oxygen content is less than 2% by weight.
• the vanadium and carbon constituents of the addition agent "ice ' by processing ammonium metavanadate, is blended with carbon, e.g. Thermatomic carbon and the mixture is briquetted under a pressure of about 100 to 10,000 p.s.i. while using about 1.5 to 2% Mogul 2 with about 15% to 20% water as a binder.
• V 0 in the practice of the present invention is suitably 65 mesh by down and suitable sizing for the carbon is 200 mesh by down.
• the proportion of carbon used in the mixture is preferably the stoichiometric amount indicated by the following equation:
• the resulting agglomerates are preferably dried at a temperature from about 200 to 250 F. to remove at least about of the moisture. Higher drying temperatures are to be avoided in order to prevent oxidation of the mixture.
• the briquets are charged to a vacuum furnace and preferably arranged therein on graphite slabs to avoid possible reaction with fur-nace refractories.
• the afore-described reaction tends to go to the right at atmospheric pressure and at temperatures of 1500- 1700 C. it has been found that the reaction is incomplete and the material obtained has an oxygen content of 2% or more and a carbon content of more than about 13%.
• the present invention is practiced under vacuum conditions and at a much lower temperature range of l200 C.1400 C. so that a product is produced in which the predominant proportions of combined vanadium is in the form of V C and in which the oxygen, free carbon and nitrogen contents of the product can be controlled at very low levels.
• the furnace is initially evacuated to a pressure below about 300 microns and the temperature is increased to 1200-l400 C. at a convenient rate so that the reaction proceeds and is completed at 1200-1400 C. and at a pressure of less than 300 microns.
• the reaction proceeds, starting at a threshold temperature of about 1200 C., pressure may increase in the furnace up to about 20 mm. due to evolution of CO, however, as the reaction goes to completion the CO pressure drops and when the CO pressure goes below about 300 microns the reaction is considered complete. That is, the reduction reactionis completed at a temperature of 1200-l400 C. and 300 microns pressure or less.
• the product obtained in this manner is in the form of strong, dense briquets containing less than 2% oxygen, and less than 0.15% nitrogen and in which the predominant proportion of combined vanadium is in the form of V C.
• the product addition agent of the present invention is also characterized by being strong, non-pyrophoric and by having good solubility in molten steel.
• finely divided iron powder suitably sized from mesh by down is blended 'with V 0 and carbon prior to briquetting.
• the proportion of iron powder used is that which provides ranges from 2 to 10%, preferably 5% by Weight 1 Trademark of R. T. Vanderbilt C0. "Trademark of Corn Products Co.
• the product briquets in the amount of 3.7 lbs., analyzed 12.7% combined carbon and contained 0.33% oxygen.
• Example II A mix was prepared as in Example I and briquets sized 2" x 2" x 1 /2" were prepared from the mix by pressing and drying under the same conditions. The resulting briquets in the amount of 10.3 lbs. were charged to the same vacuum furnace as in Example I.
• Example 111 A mix was prepared having the following proportions: 400 lbs. of V 0 sized 65 mesh by down, 136 lbs. of carbon 200 mesh by down, 9 lbs. of Mogul and 20% water.
• Briquets sized 2" x 2" x 1 /2" were prepared from the mix by pressing at 3000 p.s.i. and drying at 250 F. The resulting briquets in the amount of 1030 lbs. were charged to a vacuum furnace having interior working dimensions of 110" x 66" x 27".
• Briquets sized 2" x 2" x 1 /2" were prepared from the mix by pressing at 3000 p.s.i. and drying at 250 F.
• the resulting briquets in the amount of 64 lbs. were charged to a vacuum furnace having interior dimensions
• the pressure in the furnace was reduced to 150 microns and the temperature was raised to 1385 C.
• the pressure rose to 5000 microns and after about 60 hours at 1385 C. the pressure dropped to 175 microns and the furnace and contents were cooled to room temperature under a positive pressure of argon.
• the product briquets in the amount of 31.6 lbs., analyzed 85.45% vanadium, 11.4% combined carbon, 2.16% iron, 0.28% oxygen, and 0.09% nitrogen.
• Briquets sized 2" x 2" x 1 /2" were prepared from the mix by pressing at 3000 p.s.i. and drying at 250 F. The resulting briquets in the amount of 4164 lbs. were charged to a vacuum furnace having interior working dimensions of x 66" 'x 27".
• the pressure in the furnace was reduced to microns and the temperature was raised to 1385" C.
• the pressure rose to 12 mm. at this temperature and after about 48 hours at 1385 C. the pressure dropped to 150 microns and the furnace and contents were cooled to room temperature under positive pressure of argon.
• Briquets sized 2" x 2 x 1 /2" were prepared from the mix by pressing and drying at 250 F.
• the resulting briquets, in the amount of 29.1 lbs. were charged to a vacuum furnace having interior dimensions of 40" x 12" x 7".
• the pressure in the furnace was reduced to 200 microns and the furnace was heated to 1385 C. Due to evolution of CO the pressure rose to 500 microns. After about 24 hours the pressure dropped to 100 microns and the furnace and contents were cooled to room temperature under vacuum.
• the product briquets in the amount of 16.8 lbs., containing approximately 2% iron analyzed 12.48% combined carbon and 0.19% oxygen.
• Example VII Quantities of briquets in accordance with the present invention were made from the following basic mix order with various iron contents. In all cases, the iron addition was iron powder sized 100 mesh by down.
• the average re- 111 a further embodiment of he Present ihvellholi'l, a n are Shown i T bl 11 nitrified vanadium-containing addltl-on agent is provided in which the vanadium, carbon and nitrogen content con- TABLE II forms to the empirical formula V CN Fe content: Loadmg to fallure
• This addition agent is produced by contacting the previ- 0% 360 ously described as-pr'oduced material of the present in- 2% 460 vention with nitrogen at a temperature of 1000 C. or 5% 745 above and, before cooling, in an amount at least sufiicient 10% 693 3 to convert the V 0 in the material to V CN.
• the result- 15% 610 ing material satisfies the empirical formula Table II shows that iron contents from 2% to 10% 1.49 2.42 0.a5 1.20 'f Particularly 5 to e Provide Substantially and the predominant proportion of combined vanadium Increased trength W1th% bemg the strongest is in the form of V CN.
• This nitrided material is also The bnquets In the tests of Table II were strong, and is characterized by high density and a low 1%" X 1%" x pillows and were tested uslng standard oxygen content of less than 2%. comlimssion test. equipment having a Self-aligning The following Example VIII illustrates this embodi- Presslon head' ment of the present invention.
• Vc addition was made following the Practice of the P to a vacuum furnace having interior dimensions of ent invention except that the carbon content of the re- 0" X X 2 action mixture was increased to Provide a Product
• the pressure in the furnace was reduced to 200 microns sentially in form of I and the temperature was raised to 13 85 C.
• the pressure TABLE III rose to 20 mm. at this temperature and after about 60 hours at 1385 C. the pressure dropped to 175 I111CIOI1S Composition Percentvanadium Average solution 55 and the carbide phase was completed.
• the temperature Added Time, seconds was then lowered to 1100 C.
• a process for producing vanadium-containing adtents of between about 3% and 10% are found to be dition agents which comprises compacting finely divided especially high in 2
• high Va 70 V 0 with carbon said carbon being at least the stoichiotent is of significant advantage as regards the solubility metric amount to reduce the V 0 and form V C but not of the addition agent in molten steel. exceeding about of stoichiometric; heating the com-
• Table IV except for density, was pact material to between about 1200 C. and 1400 C. obtained using X-ray difiraction and optical microscopy under vacuum conditions to cause reaction between said techniques.
• a process for producing vanadium-containing addition agents which comprises compacting finely divided V with carbon and iron, said carbon being at least the stoichiometric amount to reduce the V 0 and form V C but not exceeding about 110% of stoichiometric; heating the compacted material to between about 1200 C. and 1400 C. under vacuum conditions to cause reaction between said carbon and said V 0 and completing the reaction at a temperature of between 1200 C. and 1400 C. and at a pressure of 300 microns or less.
• reaction product is contacted with nitrogen gas before cooling below about 1000 C., said nitrogen being in an amount sufiicient to convert V C in the reaction product to VZCN.
• a process for producing vanadium-containing addition agents which comprises compacting finely divided V 0 with carbon and iron oxide, said carbon being at least the stoichiometric amount to reduce the V 0 and iron oxide to form V C and elemental iron but not exceeding about 110% of stoichiometric; heating the compacted material to between about 1200" C. and 1400 C. under vacuum conditions to cause reaction between said carbon and said V 0 and iron oxide and completing the reaction at a temperature of between 1200 C. and 1400 C. and at a pressure of 300 microns or less.
• reaction product is contacted with nitrogen gas before cooling below about 1000" C., said nitrogen being in an amount sufircient to convert V C in the reaction product to VZCN.
• An addition agent for use in the manufacture of steel consisting essentially of vanadium, carbon and about 2 to 10% iron, said addition agent being at least in the form of combined vanadium and carbon and containing less than 2% oxygen, with the predominant pro portion of combined vanadium being in the form of V C and the atomic ratio of vanadium to carbon being in the range of 1.49 to 2.42.
• An addition agent in accordance with claim 7 which contains about 5% iron.
• An addition agent for use in the manufacture of steel consisting substantially of vanadium, carbon, nitrogen and about 2 to 10% iron, said addition agent being at least 80% in the form of combined vanadium, carbon and nitrogen and containing less than 2% oxygen, with the predominant proportion of combined vanadium being in the form of V CN, the atomic ratio of vanadium to carbon being in the range of 1.49 to 2.42 and the atomic ratio of nitrogen to carbon being in the range of 0.35 to 1.20.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Mechanical Engineering (AREA)
• Inorganic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Carbon And Carbon Compounds (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Manufacture And Refinement Of Metals (AREA)
• Transformers For Measuring Instruments (AREA)

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Cited By (22)

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• 1964
  • 1964-01-27 US US340498A patent/US3334992A/en not_active Expired - Lifetime
• 1965
  • 1965-01-26 GB GB3286/65A patent/GB1096731A/en not_active Expired
  • 1965-01-26 SE SE01000/65A patent/SE326044B/xx unknown
  • 1965-01-27 AT AT67665A patent/AT264564B/de active
  • 1965-01-27 JP JP40004069A patent/JPS5012370B1/ja active Pending
  • 1965-01-27 NO NO156521A patent/NO115037B/no unknown
  • 1965-01-27 DE DE1483312A patent/DE1483312C2/de not_active Expired
• 1967
  • 1967-01-26 BE BE693228D patent/BE693228A/xx not_active IP Right Cessation
  • 1967-07-14 JP JP42045140A patent/JPS5141568B1/ja active Pending

Patent Citations (1)

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