Showing papers on "Carbide published in 1968"

Hardfacing compositions and gage hardfacing on rolling cutter rock bits

Abstract: The novel hardfacing compositions are sintered tungsten carbide granules in an alloy steel matrix, the granules consisting of grains of monotungsten carbide cemented together with a number of novel binders - iron, nickel, alloys of the three iron group metals and metallic alloys including at least one iron group metal and at least one metal outside such group. Also disclosed are granules comprising a mixture of monotungsten carbide and ditungsten carbide cemented together with a metallic binder, preferably iron. Such hardfacings are particularly useful when welded to the gage surfaces of rolling cutters of rock bits, particularly rolling cone cutters made of alloy steel. In such applications the granules are preferably of rounded and chunky shapes, avoiding the sharp edges and corners and the slivery shapes which are likely to go into solution with the matrix. Part of the matrix comes from the melted surface of the alloy steel cutter and part preferably comes from a hardfacing welding tube containing the granules. These rolling cutter gage hardfacings may also utilize compositions heretofore known but not previously used as gage hardfacings, e.g., monotungsten carbide granules with a cobalt binder. Success achieved by the inventors may be attributable in part to powders of ferromanganese and ferromolybdenum added with the granules as part of the filler in the welding tube, a preferred pre-application composition being about 1.0 percent manganese, 0.25 percent molybdenum, balance essentially low carbon steel.

Band Structure and the Titanium LII, III X‐Ray Emission and Absorption Spectra from Pure Metal, Oxides, Nitride, Carbide, and Boride

Abstract: The titanium LII, III x‐ray emission and absorption spectra (λ∼27.5 A) from pure metal, oxides, nitride, carbide, and boride have been investigated using a plane‐crystal vacuum spectrometer with electron‐beam excitation and flow‐proportional counter detection. Emission spectra were studied over a wide range of accelerating voltages and takeoff angles, showing that satellite emission and self‐absorption effects can significantly distort the band shapes and energy positions of intensity maxima. A replica of the LII, III absorption spectrum can be constructed solely from emission spectra affiicted with widely different amounts of self‐absorption. The LII, III emission spectra from the oxides, nitride, and carbide exhibit an important crossover transition from the 2p level of the anion to the LII and LIII levels of titanium. Results indicate formation of a 3d band in titanium compounds which is only partially filled, giving rise to metallic conduction. X‐ray data is compared to density of states calculations ...

Interphase Precipitation in Iron Alloys

Abstract: During the decomposition of austenite to ferrite in certain iron-base alloys a new form of precipitation has been observed at the ferrite/austenite interface. In appropriate alloys, V4C3, Mo2C, and Cr7C3 form very fine particles on the interface, which repeatedly moves on to provide fresh sites for further nucleation. The transformation leads to a very fine banded dispersion of carbide in ferrite having striking morphological differences from the same carbides in tempered martensite.

A Study of the Mössbauer Effect during the Tempering of Iron-Carbon Martensite

Abstract: The Mossbauer effect of 57 Fe in the iron-carbon martensite steels was measured during their tempering process, and the appearance of the e -, χ- and cementite phases and the bonding nature in them were studied. It was clarified that the χ-carbide is formed at the tempering stage III a, the formation of which had not been fully proved in previous X-ray or magnetic measurements. It was also concluded that the electronic states of the iron atoms co-ordinating the carbon atoms in the martensite and the e -carbide formed in the stage I are substantially the same, suggesting that the motive force in the stage I is mainly the relaxation of the large strain energy in tne martensite structure. The observed localized and additive nature of the iron-carbon interaction, which was concluded from the linear relation between the amount of the internal field reduction and the number of carbon co-ordination for iron atoms in the various phases, seems to indicate that the Alexander-Anderson-Moriya's idea is applicable to ...

Low-temperature electrical properties of some transition metals and transition-metal carbides☆

Abstract: The specific electrical resistivities of seven transition metal carbides (zirconium carbide, hafnium carbide, niobium carbide, tantalum carbide, dimolybdenum carbide, ditungsten carbide, and tungsten carbide) and ten transition metals (scandium, yttrium, titanium, zirconium, hafnium, niobium, tantalum, chromium, molybdenum, and tungsten) were measured between 2 ° and 300 °K. The data were fitted from 2 °K, or higher for the superconducting materials, to the crossover temperature T0 by the expression g(T) = ϱ0+βTn, and from T0 to 300 °K by the Bloch-Gruneisen function plus a constant. The latter expression represented the high-temperature data well, whereas the low-temperature expression represented most of the data fairly well. The parameters derived from these two expressions are discussed and compared.

Cutting of deposit forming steel and cutting tools for such steels

Abstract: Efficient cutting of deposit forming steels, such as described in French Pat. No. 1,387,441, with tungsten carbide cutting insert having a high tungsten carbide content over an extended period of time is difficult. Efficient cutting of such deposit forming steels over a wide speed range from about 50 to about 350 m/min is made possible by embodying in the cutting edge surface stratum of the cutting tool at least 15 percent of one or more of the carbides or borides of Ti, Ta, Zr, Nb and V, or at least 50 percent aluminumoxide in the tool surface stratum may be embodied either by diffusion, or by affixing such surface layer to a known tungsten carbide insert, or by sintering stratified compacts of powder particle mixtures cohering a thick powder mixture layer containing a large proportion of tungsten carbide is covered along one or on its opposite layer surfaces with a thin powder mixture strata, each of which contains at least 15 percent of one or more of the carbides or borides of Ti, Ta, Zr, Nb and V.

Relative stability of carbide and intermetallic phases in nickel-base superalloys

Abstract: Twelve nickel-base superalloys were examined utilizing microscopy and residue analysis techniques to identify and to determine the relative stability for long times (up to 5000 hours) of gamma-prime and the minor phases in the 1400-2100°F temperature range. The materials studied included seven cast alloys, IN 100, B-1900, lnco 713C, MAR-M200, MAR-M246, TRW-NASA'IVY and TRW-NASA VIA,and five wrought alloys, U-700, Rene' 41, lnconel 718, Waspaloy and Unitemp AF2-ID. Seven minor phases were identified: MC, sigma, mu and Ni Cb.

Cvd process for producing tungsten carbide and article of manufacture

Abstract: DISCLOSED IS A PROCESS FOR DEPOSITING A METAL CARBIDE IN THE FORM X2C WHERE X IS TAKEN FROM THE GROUP CONSISTING OF TUNGSTEN, MOLYBDENUM AND CHROMIUM BY HEATING A SUBSTRATE TO A TEMPERATURE BETWEEN ABOUT 400*C. AND ABOUT 1300*C. AND PASSING A REACTANT STREAM COMPRISING A HALIDE OF THE METAL AND CARBON MONOXIDE AT ABOUT ATMOSPHERIC PRESSURE, OR GREATER, OVER THE SUBSTRATE. THE ADDITION OF HYDROGEN TO THE REACTANTS RESULTS IN A COHERENT MASS OF THE CARBIDE. A COHERENT LAYER OF THE CARBIDE MAY BE ADHERENTLY DEPOSITED ON A SUBSTRATE SUCH AS STEEL BY FIRST PASSING A REACTANT STREAM COMPRISING A HALIDE OF THE METAL X AND HYDROGEN AS A REDUCING AGENT OVER THE HEATED SUBSTRATE TO DEPOSIT A THIN LAYER OF THE METAL X, THEN ADDING THE CARBON MONOXIDE TO THE REACTANT STREAM TO PRODUCE THE METAL CARBIDE. THE HALIDE OF THE METAL X IS PREFERABLY A HEXAFLUORIDE OF THE METAL X AND THE CARBON MONOXIDE IS PREFERABLY PROVIDED BY THE CARBONYL OF THE METAL X. D R A W I N G

Formation of Silicon and Titanium Carbides by Chemical Vapor Deposition

Abstract: A major difference is demonstrated in the mechanisms whereby silicon and titanium carbides are deposited at high temperatures from gas mixtures containing the appropriate tetrachloride, hydrogen, and methane. For silicon carbide, reduction of the halide by hydrogen to elemental silicon is involved, whereas for titanium carbide the process does not involve elemental titanium. It is proposed that initial formation of pyrocarbon is required for the deposition of titanium carbide near 1200°C or that gas phase reactions involving subhalides are important.

Production of inorganic fibrous materials

Abstract: 1,224,435. Inorganic fibres. CELANESE CORP. 27 Feb., 1969 [28 Feb., 1968], No. 10576/69. Headings C1A and C1N. An inorganic filamentary material is produced by forming an acidic spinning solution of an organic filament-forming polymer containing an inorganic compound dissolved or suspended therein, spinning the solution, initially oxidizing the precursor filamentary material by heating it in a free oxygen-containing atmosphere to obtain an infusible charred product retaining a filamentary configuration and incapable of sustaining combustion when exposed to a match flame and, finally, sintering the charred product at 1200‹ to 2800‹ C. The polymer may be a polyamide, preferably polyhexamethylene terephthalamide. The inorganic compound is preferably titanium dioxide, boric oxide or aluminium oxide. The product fibre may be a carbide, the sintering being carried out in a nitrogen or argon atmosphere, or an oxide, the sintering being carried out in a free oxygen-containing atmosphere. Examples describe the preparation of filamentary titanium dioxide, aluminium oxide, titanium carbide, aluminium carbide and boron carbide.

Process for the deposition of refractory metal and metalloid carbides on a base material

Abstract: A PROCESS FOR THE DEPOSITION OF REFRACTORY METAL OR METALLOID CARBIDES ON FERROUS AND NON-FERROUS BASE MATERIALS BY HEAT REACTING A HYDROCARBON AND HALIDE VAPORS OF THE METAL OR METALLOID TO BE DEPOSITED IN A HYDROGEN ATMOSPHERE, THE HYDROCARBON CONCENTRATION BEING AT LEAST .5% PER VOLUME AND THE TEMPERATURE OF REACTION BEING AT LEAST 1050*C.

Preparation of iron carbide (fe3c)

Abstract: Essentially pure iron carbide in high yield is prepared by reducing iron oxide in the presence of carbon monoxide at temperatures in the range of 500°-550°C.

Composite product and method of making same

Abstract: A composite product and method of producing same having a substrate or matrix comprising carbonized fibers in which a metallic salt solution consisting of a soluble metal salt selected from a group consisting of Hf, Zr, Ta, Cb, W, Mo, Ti, V, Cr, Si, B, P and Pb, which form either carbides which are refractory or oxides which melt and are capable of forming a liquid surface (which will slow the diffusion of oxygen to the graphite surface causing either C + 1/202 -> CO or C + O2 -> CO2, depending upon the pressure and temperatures used in the end use). Said metallic salt when dissolved in a solvent of water or a solvent containing acetone, alcohol, ether or the like, is introduced into the interstices of the substrate and which after drying is left in fine particles. The composite is then heated to a temperature in the range of 1,500* to 2,500* F. with or without hydrogen atmosphere to effect partial reduction of the metallic salt. Almost simultaneously, carbon is infiltrated into the substrate to enclose the fibers and the metal particles. Subsequently the substrate is raised to a temperature of between approximately 1,400* C. and approximately 2,800* C. to anneal the pyrocarbon and convert the reduced metallic salt into carbide, thus producing a composition product having the substrate fibers surrounded by dead soft annealed graphite intimately mixed with hard carbide particles of very high melting point. The metal salt impregnated matrix, the reduced and/or not pyrocarbon coated metal salt in the matrix and the reduced, pyrocarbon coated, carbide converted metal salt or oxidized variations thereof are all referred to hereafter as alloys of the matrix.

Phase equilibria in the systems vanadium-chromium-carbon, niobium-chromium-carbon, and tantalum-chromium-carbon

Abstract: The systems V-Cr-C, Nb-Cr-C, and Ta-Cr-C were investigated by x-ray diffraction and metallographic techniques. The phase equilibria in the system V-Cr-C at 1000°C and the existence of a compound of the approximate composition VCr2C2 were established. The solid solubility of chromium in VC is 30 at.% and in V2C 32–33 at.%. The phase equilibria in the systems Nb-Cr-C and Ta-Cr-C at 1050 and 1000°C were also determined. The ternary carbide Nb3Cr3C was not detected.

Method of growing silicon carbide whiskers

Abstract: A method of growing silicon carbide whiskers of high quality and in high yield involves reacting a gas mixture of about 80-95 percent by volume hydrogen, 0.4-4 percent by volume hydrocarbon gas, 0.3-15 percent by volume carbon monoxide and 3-10 percent by volume inert carrier gas in a vapor atmosphere of silicon monoxide at an elevated temperature. The product is principally long-length, hairlike silicon carbide whiskers of high quality, and in high yield.

Electrolysis of brine using coated carbon anodes

Abstract: NOVEL ELECTRODES ARE DESCIRBED HAVING AN ELECTROCONDUCTIVE BASE AND A COATING APPLIED TO THE BASE. THE COATING CONSISTS OF THE SULFIDES, NITRIDES, BORIDES AND CARBIDES OF THE ELEMENTS ALUMINUM, TANTALUM, TITANIUM, BISMUTH, TUNGSTEN, ZIRCONIUM AND HAFNIUM MIXED WITH THE METALS, OXIDES, SULFIDES, NITRIDES, BORIDES AND CARBIDES OF THE ELEMENTS, GOLD SILVER, PLATINUM, PALLADIUM, RUTHENIUM, RHODIUM, IRIDIUM, OSMIUM, NICKEL, CHROMIUM, LEAD, COPPER AND MANGANESE. THE USE OF THE NOVEL ELECTRODES IN ALKALI METAL CHLORINE CELLS, BOTH DIAPHRAGM AND MERCURY TYPE, ALKALI METAL CHLORATE CELLS AND OTHER SIMILAR ELECTROLYTIC APPLICATIONS IS DISCLOSED.

An Investigation of Carbide Precipitation in Iron

Abstract: A study has been made of the carbides precipitated by quench-ageing in iron-carbon alloys containing various amounts of nitrogen in solution, or 1% nickel, by eletron microscopy of carbon replicas after ageing at 150–300°C for up to 600 h. The precipitation processes were followed by means of internal-friction measurements; the precipitates consisted of e-carbide and cementite, and the conditions of time and temperature for the occurrence of each type were determined. It has been established that the precipitation of carbon is a two-stage process; furthermore, carbon and nitrogen appear to precipitate independently. The extra internal-friction peaks observed in a 1.5% Al-containing alloy are regarded as being due to interaction between carbon atoms and single Al atoms or Al pairs. In a 0.37% Mn-containing alloy the presence of extra internal-friction peaks caused by N/Mn interaction has been confirmed. No extra damping peaks were displayed by a 1% Ni-containing alloy. The rate-determining process...

Field ion microscopy of refractory metal carbides

Abstract: Certain refractory metal carbides are shown to produce satisfactory feld ion microscope images. In the case of tantalum carbide it is shown that even extensive non-stoichiometry does not significantly degrade image quality. The influence of bond character on field evaporation behaviour is qualitatively explored in an attempt to explain the marked difference in behaviour between TaC and TiC.

Fast-Neutron Effects on the Carbides of Titanium, Zirconium, Tantalum, Niobium, and Tungsten

Abstract: Solid cylindrical specimens (½- × ½-in.) of the monocarbides of Ti, Zr, Ta, Nb, and W, made by 1) hot pressing, 2) slip casting and sintering, and 3) explosion-pressing and sintering, were irradiat...