Abstract: The coatings are glass compositions which consist essentially of from 18 to 45 mol % of the alkaline oxides CaO and one or both of Na.sub.2 O and K.sub.2 O and from 5 to 22 mol % of Al.sub.2 O.sub.3, the balance being B.sub.2 O.sub.3 and SiO.sub.2 in such amounts that the molar ratio of B.sub.2 O.sub.3 : (B.sub.2 O.sub.3 +SiO.sub.2) lies in the range from 0.575:1 to 0.85:1. The molar ratio of K.sub.2 O: (K.sub.2 O+Na.sub.2 O) is from 0.4:1 to 0.6:1 and CaO is 48 to 52 mole % of the alkaline oxides.These compositions are particularly suitable for use during the heat-treatment and hot-working of titanium and its alloys.

Abstract: An aqueous magnesia slurry for forming an insulative glass coating on silicon steel, wherein a substantial portion of the magnesia is inactive (a citric acid activity greater than 200 seconds), a decomposable phosphate compound is present within the range of 2% to 25% by weight calculated as P.sub.2 O.sub.5, based on the dry weight of magnesia, and the magnesia concentration is at least 0.24 grams per cubic centimeter of slurry. The slurry is stable against settling for up to 10 hours and has a desirable viscosity for coating application by conventional means. From 10% to 100% inactive magnesia may be used with the remainder an active magnesia (citric acid activity of 20 to 40 seconds). Preferred phosphate compounds include monocalcium phosphate monohydrate, water soluble ammonium polyphosphate and dicalcium phosphate dihydrate.

Abstract: A method of hardening the surface of steel work pieces is disclosed wherein the work piece is first treated with a solution to cause the blackening thereof and subsequently subjected to a laser beam for a time sufficient to raise the surface temperature thereof into the austenitic phase.

Abstract: An annealing separator useful for producing a grain oriented silicon steel strip having an excellent magnetic property, comprises non-hydrating magnesium oxide which has been calcined at a temperature of 1300.degree. C. or more, preferably, from 1300.degree. to 2100.degree. C., and which is in the form of fine particles, 70% by weight of which have a size of 5 microns or less, and optionally, magnesium hydroxide in an amount of 1 to 100% based on the weight of the magnesium oxide and/or an aluminium compound in an amount of 0.05 to 10% based on the weight of the magnesium oxide.

Abstract: A high adhesion uniform forsterite insulating film can be formed on the surface of a grain-oriented silicon steel sheet by the application of an annealing separator consisting mainly of magnesia having a narrow activity distribution defined by the citric acid activity of the magnesia which varies depending upon the variation of final reaction ratio of the magnesia as determined by the method for measuring the citric acid activity of magnesia, where the final reaction ratio of the magnesia is the ratio of that amount of the magnesia which finally reacts with citric acid to the total amount of magnesia mixed with the citric acid.

Abstract: The present invention is a method of generating Class 302 type carrier gas for use in carburizing processes. The gas has a composition of approximately 40% nitrogen, 40% hydrogen and 20% carbon monoxide. The nitrogen is mixed with the methanol in a vaporizer where the methanol is vaporized. The vaporized methanol and nitrogen mixture is heated in a catalyst filled retort where methanol reacts to yield hydrogen and carbon monoxide. The relative volume percents of the nitrogen, hydrogen, and carbon monoxide is substantially the same as in the Class 302 type carrier gas.

Abstract: A highly adhesive and uniform insulating film can be formed on a grain-oriented silicon steel sheet without deteriorating the iron loss of the steel sheet by the use of a magnesia series annealing separator containing a strontium compound.

Abstract: Improved core losses at high operating inductions are obtained in (110) [001] oriented silicon iron through the application of a new coating to the finish gauge material and thereafter heat treating to effect transformation of the underlying steel to the (110) [001] orientation, desulfurizing the underlying steel as well as decarburizing the same. The coating, as fused, is characterized by excellent adherence and a high interlaminar resistance value.

Abstract: A pretreatment of cold-rolled steel sheet for annealing so as to suppress graphite formation on the surface thereof and nitrogenization during the annealing for recrystallization, by causing an effective amount of sulfur, aluminum, tin, arsenic, lead, antimony, bismuth, selenium, and/or tellurium to exist on the steel sheet surface.

Abstract: A process for producing electromagnetic silicon steel having a cube-on-edge orientation. The process includes the steps of: preparing a melt of silicon steel having up to 0.07% carbon, from 0.01 to 0.25% manganese, from 0.01 to 0.09% of material from the group consisting of sulfur and selenium, from 2.5 to 4.0% silicon, up to 1.0% copper, less than 0.009% aluminum and less than 0.0006% boron; casting the steel; hot rolling the steel; cold rolling the steel; normalizing the steel in a hydrogen-bearing atmosphere having a pH.sub.2 O/pH.sub.2 of from 0.015 to 0.3; applying a refractory oxide coating containing an oxide less stable than SiO.sub.2 at temperatures up to 2150.degree. F.; and final texture annealing the steel.

Abstract: Forsterite insulating films having a high adhesion on an oriented silicon steel sheet are formed by a method wherein an annealing separator consisting mainly of magnesia is applied on surfaces of the oriented silicon steel sheet and the steel sheet is wound up into a coil-form and then annealed at high temperatures to form forsterite insulating films, which is characterized by that the content of water carried into the coil together with the annealing separator is controlled depending upon the content of CaO component carried into the coil together with the annealing separator.

Abstract: A process for producing electromagnetic silicon steel having a cube-on-edge orientation and a permeability of at least 1870 (G/O.sub.e) at 10 oersteds. The process includes the steps of: preparing a melt of a silicon steel containing from 0.02 to 0.06% carbon, from 0.0006 to 0.0080% boron, up to 0.0100% nitrogen, no more than 0.008% aluminum and from 2.5 to 4.0% silicon; casting said steel; hot rolling said steel; cold rolling said steel; decarburizing said steel; applying a refractory oxide coating containing both boron and SiO.sub.2 ; and final texture annealing said steel.

Abstract: Aluminium or silicon is diffused into iron (including silicon-iron) by applying to the iron an aqueous paste containing powdered aluminium/silicon, sodium silicate, and optionally magnesium oxide and colloidal silica, and firing it.

Abstract: A process for producing silicon steel having a cube-on-edge orientation and a permeability of at least 1850 (G/O.sub.e) at 10 oersteds, which includes the steps of: preparing a melt of steel consisting essentially of, by weight, up to 0.07% carbon, from 2.6 to 4.0% silicon, from 0.03 to 0.24% manganese, from 0.01 to 0.09% of material from the group consisting of sulfur and selenium, at least one element from the group consisting of aluminum in an amount of from 0.015 to 0.04% and boron in an amount of up to 0.0035%, up to 0.02% nitrogen, up to 0.5% copper, balance iron; casting the steel, hot rolling the steel, cold rolling the steel, decarburizing the steel, coating the steel with a base coating containing a nitrogen-bearing compound from the group consisting of (NH.sub.4).sub.2 SO.sub.4, Fe(NO.sub.3).sub.3, Al(NO.sub.3).sub.3, Mg(NO.sub.3).sub.2 and Zn(NO.sub.3).sub.2, and final texture annealing the steel.

Abstract: A cyanide-free molten salt carburizing process and composition comprising an alkali metal salt bath having a cover of finely divided graphite particles in a size range of about 100 mesh to about 300 mesh. The bath is operated in the temperature range of about 1550.degree. F. to 1900.degree. F. and is provided with mechanical agitation to produce entrainment of air through the surface cover and sufficient mobility of carbon monoxide coated graphite particles to produce carbon diffusion by contact into the surface of the parts immersed in the bath. Total graphite content is between about 11/2% to about 7% of the active portion of the bath. The graphite is preferably of the synthetic type so as to produce an ash content below about 1%.

Abstract: Gas carburizing is carried out in a subsantially closed furnace in an atmosphere initially containing hydrogen with just enough methane (or other suitable hydrocarbon gas) to provide sufficient carbon for carburization at a temperature above the austenitic transformation temperature of a ferrous metal workpiece. For each volume of methane that decomposes at the surface of the workpiece in the carburization process, two volumes of hydrogen are generated. A small amount of natural gas is fed into the furnace to maintain the carbon content of the atmosphere, and a small quantity of the predominantly hydrogen carburizing mixture is bled from the furnace to maintain a desired pressure.

Abstract: An annealing separator for use on grain-oriented silicon steel strip comprises a magnesium oxide base composition containing rare earth metal oxides. The rare earth metal oxides are present in an amount of 0.8 to 30% by weight of the composition; but in the lower range of 0.8 to 5% by weight, and preferably up to 7% by weight, the oxides have a particle size of less than 325 mesh, and a fraction of 35-55% by weight smaller than 500 mesh. Alkali metal silicate may be present in an amount 5 to 45% by weight. Strip coated with annealing separator of the invention is characterized in that the coating is almost totally free of surface cavities, in that the denitriding and desulfuring rates are greatly accelerated, in that the surface resistivity of the coating is substantially increased, and in that the coating adheres more strongly to the strip.

Abstract: Refractory metals, especially niobium and tantalum, are deoxidized by heating at 600.degree. to 1300.degree. C. under a protective gas in an alkali or alkaline earth halide salt melt containing at least 10% fluoride.

Abstract: A method of nitriding metal parts is disclosed. A preferred mode requires burying the metal part to be treated in a body of vermiculite or other porous media containing urea or other suitable nitriding agent. Prior to burying, a controlled amount of an aqueous solution of the nitriding agent is absorbed into dry vermiculite; the water of the solution is removed by evaporation leaving a pasty substance coating or impregnating the grains of the vermiculite. The pasty substance coating each vermiculite grain physically forms a thin film on the external particle surface and on the surfaces of its internal porosity; the average film thickness is less than 0.001 inch. The vermiculite bearing the nitriding agent and buried part are heated in a closed container to a temperature at which the agent decomposes at a predetermined slow rate and releases gases bearing nitrogen. Heating is continued for about 4-8 hours at 700.degree.-1300.degree. F (preferably 925.degree.-1050.degree.

Abstract: A uniform and high adhesive heat-resistant insulating film can be formed on a silicon steel sheet by applying an annealing separator consisting mainly of magnesia and containing 1-10% of titanium oxide having such a particle size that at least 99.5% of the agglomerated particles passes through 325-mesh sieve and having a dispersion degree in water of at least 85%.

Abstract: A process for producing an extremely hard, non-brittle, strongly-adhering mixed carbide layer consisting of vanadium and chromium on carboniferous ferrous materials by means of annealing to improve their specific properties such as wear resistance and corrosion resistance.

Abstract: An annealing separator for silicon steel sheets comprising not less than 90.00% by weight of an MgO and 0.01 to 2.0% by weight of B.sub.2 O.sub.3 in the form of nMgO.B.sub.2 O.sub.3 with the balance being unavoidable impurities.

Abstract: A slurry of ferrosilicon powder is applied to both sides of a low carbon steel strip. The particle size of the ferrosilicon powder is controlled so that, after the slurry coatings are dried, there exists on each side of the steel strip at least a single layer of closely packed particles. The coated strip is then compacted. It is next heated in a protective environment to cause uniform diffusion of silicon throughout the strip.

Abstract: Cold-rolled steel strip is heated to a temperature higher than its recrystallization temperature, preferably faster than 4.degree. C/s. The strip is then held for more than 30 seconds. The strip is then cooled by immersion in an aqueous bath maintained at substantially its boiling temperature within a temperature range of 80.degree.-150.degree. C.

Abstract: Portions of the surface area of metal workpieces are insulated in thermochemical treatment by covering the areas with a self-adhering textile tape having metal powder embedded in its adhesive layer.

Abstract: Iron and steel construction parts which have been treated in a high cyanate, low cyanide or cyanide free nitriding salt bath or in other cyanide containing salt baths are tempered in a bath comprising an alkali metal hydroxide. There also can be present in the cooling bath 2 to 20 weight % of an alkali nitrate.

Abstract: Atmosphere compositions and processes utilizing the compositions for heat treating ferrous metal articles under a controlled furnace atmosphere to either maintain or change the surface chemistry of the article being treated are disclosed in the following specification.The invention features atmosphere compositions or mixtures which are blended from normally gaseous components outside the furnace and the mixture or blend is injected into the furnace to provide a carburizing, decarburizing, carbonitriding or neutral hardening atmosphere inside the furnace.

Abstract: A process for controlling the nitriding effect of a nitriding bath of a salt melt containing alkali cyanate for the nitridation of iron and iron alloys wherein the nitriding effect of the bath is maintained in a specific range by determining the voltage occurring at an electrode of a solid electrolyte which conducts oxygen ions immersed in the nitriding bath.

Abstract: Iron and steel are nitrided in a salt bath in a process favorable to the environment. The salt bath consists essentially of potassium cyanate, sodium cyanate, potassium carbonate, and sodium carbonate. Preferably, air flows through the bath. The bath preferably contains 25-57 weight % of cyanate calculated as cyanate ion, 0 to 30% alkali metal chloride and the balance carbonate and alkali metal ions. Preferably cyanide is omitted, but it can be present in an amount up to 5%. Without removing the waste salt, the bath is regenerated by adding melon, melam, or melem.

Abstract: A process for producing electromagnetic silicon steel having a cube-on-edge orientation and a permeability of at least 1850 (G/O.sub.e) at 10 oersteds. The process includes the steps of: preparing an aluminum-bearing melt of silicon steel; casting the steel; hot rolling the steel; cold rolling the steel; decarburizing the steel; coating the steel with a base coating containing an amide and/or imide of an organic and/or inorganic acid; and final texture annealing the steel.

Abstract: The invention relates to a method of maintaining at very low values the portions of cyanides in molten-salt baths of the kind in which the main active principle is the cyanate anion CNO.sup.-, the method comprising essentially the steps of conjointly providing in the salt bath at least one sulphurized element in a quantity such that the proportion of the sulphur element in the bath is between 0.001 and 0.1 % of the weight of said bath, and introducing periodically or continuously into the bath at least one substance comprising at least one carbonyl group = C = O in its chemical formula, in a quantity such that it corresponds to a weight of between 1 and 25 grams of CO per kg. of bath and per 24 hours maintenance at the bath working temperature of between 480.degree. and 650.degree. C. The substance introducing the carbonyl group may also constitute a regenerating agent for the cyanate anion and can advantageously be obtained by baking carbamide for 3 to 10 hours at a temperature of between 150.degree.

Abstract: A process for quench hardening metal is provided. The process comprises heating the metal to a quench hardening temperature and thereafter immersing the metal in a quenching medium which is an aqueous solution containing 0.4 to 10% by weight of polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, or a salt thereof. The process provides a perfect and uniformly hardened quenched structure and allows the production of a quenched structure having a desired degree of hardness.

Abstract: A protective gas for annealing steel and other metals is characterized by a mixture of nitrogen and 0.2% by volume to 50% by volume of carbon monoxide.

Abstract: Disclosed is a method for heat treating nonferrous metal parts. These parts are suspended in a settable ceramic slurry. The combination is formed into a solid mass by setting of a gelling binder contained therein. The set mass is then aged in an enveloping stabilizing or hardening atmosphere in which the volatile constituents of the binder are miscible. The formed mass of ceramic and metal parts is heat treated, the parts being held in suspension by the ceramic highly refractory material. Upon cooling, the differing thermal coefficients result in a disintegration of the ceramic from the heat treated parts.

Abstract: Process for producing grain-oriented electric steel sheets having a remarkably improved magnetic flux density, comprising hot rolling silicon steel material containing 0.025 to 0.085% C, 2.0 to 4.0% Si, 0.010 to 0.065% acid soluble Al, continuously annealing the steel at a high temperature between 950.degree. and 1200.degree.C before a final strong cold rolling, rapidly cooling the steel to precipitate AlN, cold rolling the steel by a one-step or two-step cold rolling including a final strong cold rolling with a reduction rate range of 81 to 95% into the final thickness, coating a separating agent on the sheet after a decarburization annealing, and subjecting the sheet to a final annealing to obtain a grain-oriented electric steel sheet having excellent excitation characteristics and B.sub.8 characteristics of at least more than 1.90 Wb/m.sup.2, said separating agent containing 0.1 to 15% of antimony or an antimony-containing compound.

Abstract: An improved technique is described for effecting decarbonization protection for the surfaces of ferrous metals during heat treatment in an oxidation atmosphere. The surface to be protected is coated, prior to the heat treating step, with a paste-like substance preferably formed from a mixture of boron carbide, potassium boron fluoride, borax and an aqueous binder. The resulting protective coating, which may be sprayed on the relevant surface, has a maximum thickness of .1 mm. Such relatively thin coating having the described composition, which in larger thicknesses is useful for boron-hardening of metallic surfaces, is effective to provide the required decarbonization protection without the accompanying disadvantages of excessive boron atom diffusion.

Abstract: To improve recovery of nitrate-nitrite compounds from effluent of nitriding processes, a melt of the nitrate-nitrite salts is prepared and maintained at a temperature above about 400.degree. C; the effluent liquid is introduced into the melt, to evaporate the water and melt the salts contained therein to merge immediately into the melt, the melt being drawn off by an overflow. The evaporated water is filtered to recover any remaining salts, together with condensation water. Preferably, the apparatus includes a dispersion device close to the introduction duct of the effluent liquid into the melt, to prevent introduction of the effluent liquid in a solid stream; this dispersion may be an open pot with a perforated bottom located beneath the surface of the melt, a cartridge with steel wool, or the like.

Abstract: Electrical products formed of silicon steel are provided with a heat resistant electrical insulating coating by suspending particles of an oxide and/or of an hydroxide of earth alkali metal in an aqueous suspension, and adding to the suspension a substance capable of liberating hydroxyl ions which is volatile at a temperature below that at which silicate is formed. Examples of such a substance are ammonia and organic amines. There may also be added to the suspension silicon dioxide particles which are capable of oxidizing silicon to silicon dioxide at temperatures below 1300.degree.C.

Abstract: A coating composition containing 75-95% MgO, 2-10% B.sub.2 O.sub.3 and 0-15% C, which is effective in retarding oxidation of ferrous metal articles, especially at temperatures in excess of 2150.degree.F. Additional protection is achieved when about 11-17% TiO.sub.2 is substituted for about the same amount of MgO. The composition is admixed with a suitable vehicle and is applied to the metal surface in the form of a dispersion, suspension or as a slurry.

Abstract: Annealing separator for heat treatment of a silicon steel sheet comprising not more than 0.2% SO.sub.3, not more than 0.04% Cl with the balance being MgO and unavoidable impurities, and having a bulk density between 0.18 and 0.30 g/cm.sup.3, and a particle size distribution of 40 to 70% of particles not larger than 3.mu.m, 10 to 25% of particles not smaller than 10.mu.m, not more than 15% of coarse particles larger than 15.mu.m with the balance being intermediate particles between 3.mu.m and 10.mu.m.

Abstract: Coatings for silicon steel comprised of MgO, an amorphous magnesia-silica complex and a boron bearing compound.

Abstract: Coatings for silicon steel comprised of MgO, an amorphous magnesia-silica complex and a boron bearing compound.

Abstract: Novel amorphous magnesia-silica complexes containing from about 0.001 to 2.0 percent by weight of an alkali metal oxide, wherein the mole ratio of MgO:SiO.sub.2 of said complexes is from about 1:25 to 14:1.

Abstract: Method for producing a grain-oriented electrical steel sheet or strip having uniform magnetic and film properties said method comprising applying an annealing separator containing one or more metal nitrides, such as, chromium nitride, titanium nitride and vanadium nitride to the steel sheet and annealing the steel sheet at a temperature not lower than 1,100.degree.C.

Abstract: Coatings for silicon steel comprised of MgO, an amorphous magnesia-silica complex and a lithium bearing compound.

Abstract: Insulative coatings for electrical steels having improved resistance to deterioration during stress relief anneals or other heat treatments carried on in reducing atmospheres. They may be produced by coating electrical steel with an aqueous solution of phosphoric acid, magnesium oxide and one or more additional mineral acids present in an amount sufficient to adjust the pH level of the solution to from about 0.5 to about 3.0. The mole ratio Mg/PO.sub.4 should be from about 0.6 to about 1.5.

Abstract: A novel quenching medium for steel is provided. The quenching medium is a 0.5-10 wt. % aqueous solution of polyacrylic acid, polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, or a salt thereof. Intrinsic viscosity [.eta.] of the polymer is from 0.010 to 0.050 l/g. The quenching medium is superior in various quenching characteristics to conventional quenching media.

Abstract: The present invention relates to powdered boriding compositions for the production of single-phase boride layers on metal articles being substantially free from cracks in the case of mechanical stress, which comprise an activator and a mixture of a boron-releasing agent and an unreactive refractory material, such as silicon carbide.

Abstract: Magnesium oxide coating compositions, process for their preparation and process for applying said compositions as adherent dried coatings which when annealed form relatively non-porous insulations providing improved electrical insulating properties. The coating compositions comprise a major proportion of magnesium oxide and a minor proportion of zinc permanganate and magnesium sulfate, wherein the concentration of zinc permanganate is from about 4 to about 16 parts per 100 parts of magnesium oxide and the concentration of magnesium sulfate is at least about 50 parts per 100 parts of zinc permanganate.