Abstract: An improved process for diffusing a substrate into a base material is described. Generally, a process is provided for introducing a base material into a salt bath having a substrate with a catalyst. A select amount of catalyst and desired salt bath temperature are provided sufficient to lower the activation energy of the base material such that the substrate is able to easily diffuse into the surface of the base material. Nevertheless, certain substances within the base material may inhibit the diffusion of the substrate into the surface of the base material. Accordingly, a select amount of catalyst and desired salt bath temperature are further provided sufficient to promote leaching of such select substances that inhibit the diffusion of such substrate into such base material. The leached substances are substantially replaced by the diffused substrate.

Abstract: The present invention provides spring use heat treated steel which is cold coiled, can achieve both sufficient atmospheric strength and coilability, has a tensile strength of 2000 MPa or more, and can improve the performance as a spring by heat treatment after spring fabrication, that is, high strength spring-use heat treated steel characterized by containing, by mass %, C: 0.45 to 0.9%, Si: 1.7 to 3.0%, and Mn: 0.1 to 2.0%, restricting N: to 0.007% or less, having a balance of Fe and unavoidable impurities, and satisfying, in terms of the analyzed value of the extracted residue after heat treatment, [amount of Fe in residue on 0.2 ?m filter/[steel electrolysis amount]×100?1.1.

Abstract: A method of activating an article of passive ferrous or non-ferrous metal by heating at least one compound containing nitrogen and carbon, wherein the article is treated with gaseous species derived from the compound. The activated article can be subsequently carburized, nitrided or nitrocarburized in shorter time at lower temperature and resulting superior mechanical properties compared with non-activated articles and even articles of stainless steel, nickel alloy, cobalt alloy or titanium based material can be carburized, nitrided or nitrocarburized.

Abstract: To provide a metal ring excellent in durability by reducing decrease in margin of strength and concentration of tensile stress at its both widthwise end portions and to efficiently realize a production method of the same, a metal ring is formed in an endless band-like body having a nitride layer on its surface portion and constituting part of a metal belt of a belt type continuously variable transmission, the nitride layer being constituted by a first nitride layer portion positioned on an outer circumferential side, a second nitride layer portion positioned on an inner circumferential side, and third nitride layer portions positioned on both widthwise end sides, and the layer thicknesses of the third nitride layer portions being smaller than either one of the layer thicknesses of the first nitride layer portion and the second nitride layer portion.

Abstract: The invention relates to a crankshaft member having high fatigue strength and good bending correctability, and its method of manufacture. The steel made crankshaft member mainly consists of a two-phase structure of ferrite and perlite. The steel includes C, Ni, Mn, and Cr as required elements and Si, Cu, Mo, Ti, V, Nb, Ca, and S as optional elements that may be included, in the amounts of C within the range of 0.20 to 0.50 wt %, Si within the range of 0 to 0.6 wt %, Mn within the range of 0.5 to 1.5 wt %, Cu within the range of 0 to 0.7 wt %, Ni within the range of 0.05 to 1.5 wt %, Cr within the range of 0.05 to 0.45 wt %, and Mo within the range of 0 to 0.5 wt % to satisfy the condition 115?70C+8Si+23Mn+11Cu+128Cr+83Mo?50. A portion of the member surface is provided at least with a hard nitride layer having an average hardness within the range of 300 to 450 HV. Lamellar spacing of the perlite is 0.3 ?m or less.

Abstract: A method of activating an article of passive ferrous or non-ferrous metal by heating at least one compound containing nitrogen and carbon, wherein the article is treated with gaseous species derived from the compound. The activated article can be subsequently carburised, nitrided or nitrocarburised in shorter time at lower temperature and resulting superior mechanical properties compared with non-activated articles and even articles of stainless steel, nickel alloy, cobalt alloy or titanium based material can be carburised, nitrided or nitrocarburised.

Abstract: A metal composite for use in electrochemical devices is disclosed. The metal composite comprises a stainless steel interior component and a deposited nitrided metal exterior layer, wherein the nitrided exterior layer has lower electric contact resistance and greater corrosion resistance than the stainless steel interior component. A bipolar plate made of such metal composite and methods of producing the metal composite and bipolar plate are also disclosed.

Abstract: A body of iron, steel or other such ferrous material is protected from thermochemical erosion by a layer of an iron nitride having a relatively low nitrogen content. The atomic percentage of nitrogen in the iron nitride layer is no greater than 20%, and in specific embodiments is in the range of 10-15%. The nitride layer may have a layer of a refractory material deposited thereatop. Some refractory materials include metals such as chromium. The invention has specific utility for protecting gun barrels, turbines, internal combustion engines, drilling equipment, machine tools, aerospace systems and chemical reactors which are exposed to extreme conditions of temperature and pressure. Specifically disclosed is a gun barrel which incorporates the invention.

Abstract: A process for heat treating metal workpieces contains with respect to an efficient process control the following successive operations following directly one after the other: a heating phase; an enrichment phase; a first cooling phase; a bonding phase; a second cooling phase; and a concluding quenching phase. Workpieces processed by a method of this type are distinguished by a comparatively great fatigue limit and fatigue strength with simultaneous high resistance to wear and tear.

Abstract: A method for diffusing titanium and nitride into a base material having a coating thereon using conventional surface treatments or coatings. The method generally includes the steps of providing a base material having a coating thereon; providing a salt bath which includes sodium dioxide and a salt selected from the group consisting of sodium cyanate and potassium cyanate; dispersing metallic titanium formed by electrolysis of a titanium compound in the bath; heating the salt bath to a temperature ranging from about 430° C. to about 670° C.; and soaking the base material in the salt bath for a time of from about 10 minutes to about 24 hours. In accordance with another aspect of the present invention, titanium and nitride may be diffused into a base material without a coating. The treated base material may further be treated with conventional surface treatments or coatings.

Abstract: A roller bearing that provides ball and roller bearing elements comprised of M50 steel and M50NiL steel having surface hardnesses above 60 HRC, and in the range of 65-72 HRC. The hardness in the surface region is achieved by nitriding the surface to achieve a high hardness and extended life. This improvement is brought about by controlling the microstructure of the alloy by minimizing the formation of retained austenite. The material is tempered as required. The surface is then nitrided, but the nitriding operation is carefully controlled to avoid the formation of intergranular nitrides. Because of the method used to prevent the formation of intergranular nitrides, some carbon may be present to prevent the surface of the steel from becoming depleted of carbon. The hardening element in this nitro-carburizing operation is nitrogen, which forms iron nitride as Fe3N or Fe4N intragranularly.

Abstract: A high strength gear is provided which comprises a base metal of an iron-base alloy, the base metal being carburized or carbonitrided and having a tooth surface, and a coating containing Fe nitride and/or Fe carbonitride, formed on the tooth surface. A method of forming a high strength gear is also provided.

Abstract: A new nitriding process by using a salt bath to produce iron and steel parts having excellent abrasion resistance and corrosion resistance are explained. A iron lithium complex oxide layer are formed at the outermost surface of the iron part by immersing the iron and steel parts in a salt bath containing cationic component of Li, Na and K and anionic components of CNO−and CO32−, where hydroxide compound selected from lithium hydroxide, sodium hydroxide and potassium hydroxide are added to the salt bath. Materials being in a hydrated state or in a free water containing state can be used for preparation or replenishing of the salt bath. An moistend air of (1×10−2 kg·H2O)/(1 kg dry air) can be used for mixing the salt bath. Containing ratio of Li, Na, K is preferable where a solidifying temperature of the mixture of carbonates of Li, Na, K in that ratio is lower than 500° C.

Abstract: A laminated ring for use as a belt in transmitting power in a continuously variable transmission is produced by welding opposite ends of a sheet of maraging steel to produce a plurality of rings, and rolling said rings to a predetermined length. The rings are nitrided in a salt-bath nitriding process by dipping the rings in a molten salt containing 38-46% of CNO− and 1-2% of CN− and heated to a temperature in the range from 480 to 530° C., for a period of time ranging from 10 to 25 minutes. The nitrided rings are finally stacked into a laminated ring.

Abstract: A laminated ring for use as a belt in transmitting power in a continuously variable transmission is produced by welding opposite ends of a sheet of maraging steel to produce a plurality of rings, and rolling said rings to a predetermined length. The rings are nitrided in a salt-bath nitriding process by dipping the rings in a molten salt containing 38-46% of CNO31 and 1-2% of CN− and heated to a temperature in the range from 480 to 530° C., for a period of time ranging from 10 to 25 minutes. The nitrided rings are finally stacked into a laminated ring.

Abstract: In the production of grain-oriented electrical steel strip, the grain growth inhibition is controlled by balancing the copper, aluminum and carbonium content in order to control the type and quantity of precipitated second phases and obtain optimum grain dimensions during the decarburization annealing. This is done by using a continuous high-temperature thermal treatment in which nitrogen is diffused into the steel strip and aluminum is directly precipitated as aluminum nitride which controls the grain orientation of the final product.

Abstract: The production of grain-oriented electrical steel sheets is disclosed wherein grain growth in the steel is inhibited by a method comprising the regulation of the content of sulfur and manganese in the steel strp and the cold rolled strip is continuously nitrided at high temperature.

Abstract: A method for nitriding a metallic base material at low temperatures in a salt bath containing electrolyzed titanium metal. A nitride coating of exceptional depth and hardness is obtained in a very short operating time due to the rapid nitriding process. The method is applicable to steel, titanium, aluminum and alloys thereof.

Abstract: A process for the production of grain oriented silicon steel sheet which provides an optimization of the production of conventional, grain oriented silicon steel strips, by the use of an appropriate synergistic combination of the composition levels of some elements and appropriate treatments which result in the control of the presence and type of inhibitors, and by so doing, controlling the primary-recrystallization grain size.

Abstract: A member used in contact with a hot dip galvanizing bath, such as a sinker roll, a support roll or a bearing, is produced by nitriding stainless steel to form a nitride layer and a nitrogen-diffused layer on the surface thereof. The member used in contact with a hot dip galvanizing bath is formed on its surface with the nitride layer by nitriding it in a salt bath containing a cyanide, a cyanate, a carbonate and the like or by heat-treating it in an atmosphere containing ammonium or nitrogen.

Abstract: A motor rotary shaft according to the present invention is constructed only at the surface layer of a journal portion with a hard nitride layer, so that the resultant motor rotary shaft is available at a low cost, not so heavy and excellent in durability in comparison with a case employing a hard material for the whole motor rotary shaft. Also, a method of manufacturing a motor rotary shaft according to the present invention employs fluorinating process prior to nitriding process to change a passive coat layer such as oxide layer on the surface of the journal portion to a fluoride layer, which protects the same surface. Therefore, even when there is space of time between formation of fluoride on the surface of the journal portion and nitriding process, the fluoride layer protects and keeps the surface of the journal portion in a favorable condition, resulting in that re-formation of oxide layer on that surface is prevented.

Abstract: The invention relates to a method for aluminum nitride coating of cylinder contact surfaces (ZL) of a crankcase (KG) made of an aluminum basic alloy where the aluminum nitride coating is performed by surface nitriding of the aluminum basic alloy, and the activated nitrogen is generated by a high-pressure plasma process.

Abstract: The object of the present invention is to provide a simple, inexpensive method of surface treatment capable of improving the strength and smoothness of fishing tackle parts made of alloy steel containing chrome. The method of surface treatment for a fishing tackle part made of alloy steel containing chrome according to the present invention is characterized in that the surface of the fishing tackle part made of alloy steel containing chrome is nitrided to form a diffused layer of chromium nitride from the surface of said part inwards, and then said surface is covered with a layer of titanium nitride.

Abstract: Process for the preparation of a heat treatment atmosphere by a catalytic reaction in a catalytic reactor including an inlet and an outlet between a first gas mixture comprising oxygen and a second gas mixture comprising a hydrocarbon for the purpose of supplying said atmosphere to a user site comprising at least one user location, comprising the steps of:a) feeding said first and second gas mixture at a given flowrate into the inlet of said catalytic reactor;b) continuously measuring the pressure of the heat treatment atmosphere obtained at the reactor outlet;c) comparing the pressure measured during step b) with a setpoint pressure level P.sub.

Abstract: The process and system according to the present invention are used for the production of an atmosphere. The process involves feeding an impure nitrogen stream, combined with a hydrocarbon to a catalytic reactor having a non-noble metal catalyst to produce a gas which is suitable for use as an atmosphere in furnaces for thermal treatment of metals. The impure nitrogen stream, contains less than 21% oxygen and is preferably produced by a gas membrane system. The system for producing the atmosphere preferably includes a membrane separator, one or more heat exchangers and a catalytic reactor preferably having a nickel catalyst on an alumina support.

Abstract: A method of nitriding steel which comprises reacting the steel surface with nitrogen so as to form a hard nitrided layer, and, prior to nitriding, holding steel under a gas atmosphere containing fluorine compound gas or fluorine gas and also containing air of 0.5 to 20 volume % of the total or oxygen gas of 0.1 to 4 volume % of the total with heating, whereby occurrence of uneven nitriding is prevented and at the same time savings in consumption of expensive fluorine- or fluoride-containing gas can be realized.

Abstract: A substrate material to be coated with either a nitride, carbide, or oxide contains a small percent of a specific reactive element, like titanium, which forms very stable nitrides, carbides, or oxides. The material also contains larger percentages of elements, such as chromium, which form less-stable nitrides, carbides, or oxides. When the substrate material is immersed in a process medium which contains reactants, such as nitrogen, carbon, or oxygen, at a chosen elevated temperature and concentration, the less-stable nitrides, carbides, or oxides are reduced and cannot form a coating on the material surface. Thus, only a very stable nitride, carbide, or oxide can form a strong, adherent coating.

Abstract: A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a predetermined amount of a hydrocarbon gas, feeding the gaseous mixture through a nonconventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as a mixture of moisture and carbon dioxide, a mixture of moisture, hydrogen, carbon monoxide, and carbon dioxide, or a mixture of carbon monoxide, moisture, and hydrogen, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals, sintering metal and ceramic powders, and sealing glass to metals.

Abstract: An austenitic stainless steel screw having a nitride hard layer on its surface to prevent corrosion on parts of the screw such as a screw head which is in contact with the environment by removing a portion of the nitride hard layer to expose austenitic stainless steel base. By contrast, in the thread part and the like of the screw, the nitride hard layer is retained to improve the hardness and the tapping functions of the screw. In the method for manufacturing, the austenitic stainless steel screw is exposed to a fluorine-or fluoride-containing gas atmosphere prior to nitriding to form a fluoride film on its surface and then is nitrided in that state. Accordingly, the so formed nitride hard layer becomes uniform and deep to obtain an austenitic stainless steel screw having excellent surface properties.

Abstract: A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a predetermined amount of a hydrocarbon gas, feeding the gaseous mixture through a nonconventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as a mixture of moisture and carbon dioxide, a mixture of moisture, hydrogen, carbon monoxide, and carbon dioxide, or a mixture of carbon monoxide, moisture, and hydrogen, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals, sintering metal and ceramic powders, and sealing glass to metals.

Abstract: This invention relates to a method for forming a uniform, deep nitride layer on and in steel works at low cost, wherein a steel work is fluorided in heated condition in an atmosphere of a mixed gas composed of fluorine gas and inert gas and, then, nitrided in heated condition in an atmosphere of nitriding gas.

Abstract: A method of nitriding nickel alloy comprising steps of holding nickel alloy in an atmosphere of fluorine- or fluoride-containing gas in a heated condition and holding the fluorinated nickel alloy in a nitriding atmosphere in a heated condition to provide the nickel alloy with improved surface hardness by forming a deep uniform nitrided layer on the surface of the nickel alloy.

Abstract: The thermal treatment atmosphere is obtained by catalytic reaction of an impure mixture of nitrogen, advantageously obtained by permeation or adsorption, and hydrocarbon, the catalytic reaction being carried out at a temperature between 400.degree. and 900.degree. C., typically between 500.degree. and 800.degree. C., with a noble metal base catalyst, typically platinum or palladium on alumina support. The reaction may be carried out in a reactor placed inside or outside the furnace.

Abstract: A method of forming a wear-resistant coating for internal combustion engine component parts which allows the part to remain dimensionally stable under severe engine operating conditions is provided. The coating is formed by a two step method. First, the engine part is coated with chromium to form a chromium base layer. Second, the chromium coated part is subjected to a reactive gas plasma in a reaction chamber at an elevated temperature and under an applied electrical potential. The gas of the plasma reacts with the chromium to form the wear-resistant layer. Preferably, the reactive gas is nitrogen which reacts with the chromium to form a chromium nitride surface layer on the chromium base layer.

Abstract: A process for generating in-situ low-cost atmospheres suitable for annealing and heat treating ferrous and non-ferrous metals and alloys, brazing metals and ceramics, sealing glass to metals, and sintering metal and ceramic powders in a continuous furnace from non-cryogenically produced nitrogen containing up to 5% residual oxygen is presented. The disclosed process involves mixing nitrogen gas containing residual oxygen with a pre-determined amount of a reducing gas such as hydrogen, a hydrocarbon, or a mixture thereof, feeding the gaseous mixture through a non-conventional device into the hot zone of a continuous heat treating furnace, converting residual oxygen to an acceptable form such as moisture, a mixture of moisture and carbon dioxide, or a mixture of moisture, hydrogen, carbon monoxide and carbon dioxide, and using the resultant gaseous mixture for annealing and heat treating metals and alloys, brazing metals and ceramics, sintering metal and ceramic powders, and sealing glass to metals.