Abstract: A method for treating a brass fixture having a fluid-contacting surface with lead dispersoids exposed thereon to reduce lead leaching into a fluid supply by contacting the brass fixture with a liquid metal solution selected from the group consisting of a liquid sodium solution, a liquid potassium solution and a liquid metal alloy solution to dissolve lead dispersoids from the fixture, wherein the metal alloy comprises a metal selected from the group consisting of sodium and potassium.

Abstract: The inner surface of ethylene furnace tubes is diffusion coated with a sufficient amount of chromium or chromium and silicon to form a first coating having a thickness of at least two mils. This coating is then cleaned, neutralized, and grit blasted. Then a second coating of a sufficient amount of aluminum or aluminum and silicon is diffused onto the first coating to form a total coating thickness of at least five mils. The surface of the second coating is cleaned and polished to remove the nickel and iron-rich overlay which is present as a result of the coating process and to provide a smooth uniform surface. When ethelyene is produced using furnace tubes which are coated in this manner less coking occurs.

Abstract: In order to produce a carbon solid solution or carbide-containing surface layer on a substrate, the substrate is immersed into a cold bath of liquid active medium, and heated inside the liquid active medium by heating means immersed in the liquid active medium as well.

Abstract: A method for fabricating an electrically insulating coating on a surface is disclosed comprising coating the surface with a metal, and reacting the metal coated surface with a nonmetal so as to create a film on the metal-coated surface. Alternatively, the invention provides for a method for producing a noncorrosive, electrically insulating coating on a surface saturated with a nonmetal comprising supplying a molten fluid, dissolving a metal in the molten fluid to create a mixture, and contacting the mixture with the saturated surface.

Abstract: In a method of increasing the wear resistance and the corrosion resistance f opposed bearing surfaces of parts subjected to reciprocal friction, in particular when the product of the pressure distributed over the bearing surfaces by the relative speed of the latter exceeds 0.4 MPa.m/s, thermochemical diffusion of nitrogen is effected by nitriding or nitrocarburizing in a molten salt bath at a temperature of 570.degree. C..+-.15.degree. C. followed by an oxidizing or phosphating surface chemical reaction providing resistance to wet corrosion. The nitriding or nitrocarburizing molten salt bath is made up of alkaline carbonates and cyanates and further contains sulfur-containing substances in the following percentages by weight:30%<CNO.sup.- <45%15%<CO.sub.3.sup.2- <25%15%<Na.sup.+ <25%20%<K.sup.+ <30%1%<Li.sup.+ <6%1 ppm<S.sup.2- <100 ppmThe time for which parts are immersed in the bath is between 15 minutes and 45 minutes.

Abstract: Flawless nitrating layers are obtained during the nitro-carburizing of components made from steels which form passive layers in salt baths if these components are first pre-treated in an oxidizing salt melt at 300.degree. to 500.degree. C. prior to the nitro-carburizing process.

Abstract: The invention relates to a surgical needle with a suture material or thread fixed to the end opposite to the perforation tip, characterized in that the puncturing tip and the area of the needle following onto the latter is made up to approximately 50% of its length from bare or surface-untreated metal, whereas the surface of the remaining part of the needle and up to the thread shoulder is chemically or electrolytically of a coating dulled or coloured in a continuous manner or with minor interruptions.

Abstract: A phosphate bath control system and method is provided that tracks the set points of one or more of the major process variables of the phosphate bath independently of variations in the production conditions. A detector determines the current values of Zinc, Manganese and Total Acid provides data to a controller which exponentially filters the data and processes the filtered data in accordance with fuzzy logic rules. The controller periodically updates the flow rate of one or more pumps that control the flow of liquid concentrates to the bath in order to maintain a desired concentration of the various constituents of the bath. Control of an accelerator is provided by incorporating in the controller an additional algorithm for indirect estimation of the accelerator concentration based on a math model which represents the material balance of the accelerator in the bath.

Abstract: An alloying-treated iron-zinc alloy dip-plated steel sheet excellent in press-formability, having, on the surface thereof, numerous fine concavities which satisfy the following conditions: (1) that the number of fine concavities having a depth of at least 2 .mu.m is within a range of from 200 to 8,200 per mm.sup.2 of the plating layer, and (2) that the total opening area per unit area of the fine concavities in the plating layer is within a range of from 10 to 70% of the unit area. The above-mentioned plated steel sheet is manufactured by subjecting a cold-rolled steel sheet to a zinc dip-plating treatment in a zinc dip-plating bath having an aluminum content of from 0.05 to 0.30 wt. %, in which the temperature region causing an initial reaction for forming an iron-aluminum layer is limited within a range of from 500.degree. to 600.degree. C., an alloying treatment in which an alloying treatment temperature is limited within a range of from 480.degree. to 600.degree. C., and a temper-rolling treatment.

Abstract: A process for improving the wear and corrosion resistance of ferrous metal arts consists in immersing the parts, which have previously been treated using a nitriding, diffusion technique, in a molten salt bath comprising carbonates, nitrates, hydroxides and oxygenated alkali metal salts. The relative anionic proportions by weight of carbonates, nitrates and hydroxides expressed in terms of their sodium salts and corresponding to the active phase, that is the liquid in the bath, are as follows:11<CO.sub.3.sup.2- <2319<NO.sub.3.sup.- <376<OH.sup.- <19and the proportion by weight of oxygenated alkali metal salts, expressed in equivalents of Cr.sub.2 O.sub.7.sup.2- is as follows: 0.05<oxygenated anions<0.41. This process guarantees a high degree of reproducibility of results regardless of the type of treated part.

Abstract: A salt bath composition is adapted to form a layer of magnetite Fe.sub.3 O.sub.4 on the surface of ferrous metal parts, including nitrided ferrous metal parts, to protect the underlying iron against corrosion. This layer is impermeable and of good crystalline order, as indicated by a deep black color and a corrosion potential greater than 1 000 mV. The composition includes at least nitrate anions and sodium and lithium cations, the latter in a proportion by weight relative to the bath between 0.1% and 5%, preferably between 0.5% and 1.75%. Preferred compositions contain sodium, potassium and lithium cations and nitrate, carbonate and hydroxyl anions, within the following percentage ranges:8.5 .ltoreq.CO.sub.3.sup.2- .ltoreq.2615 .ltoreq.NO.sub.3.sup.- .ltoreq.41.54.7.ltoreq.OH.sup.- .ltoreq.21.

Abstract: A method of galvanizing ferrous linear elements, e.g., tube, pipe, structural shapes, as part of a continuous manufacturing line by passing the axially travelling preheated element through transversely flowing molten zinc.

Abstract: An alloy has less stable oxides, e.g. nickel oxide, chromium oxide, and iron oxide on a surface (FIG. 1 ). The material has specific reaction elements such as titanium and aluminum in a relatively low concentration throughout the alloy. At an elevated temperature, the surface of the alloy is subject to a fluid which reduces the nickel, chromium, and iron oxides and the aluminum or titanium adjacent the surface reduces components of the fluid (FIG. 2 ). The alloy is maintained at the elevated temperature in the presence of the fluid until a barrier film of the specific reactive elements is formed. In one embodiment, the working fluid is a gaseous fluid of hydrogen or an inert gas with water vapor. The hydrogen of the water vapor reduces the less stable oxides and the oxygen oxidizes the specific reaction elements. In another embodiment, the working fluid is a liquid metal other than lithium which carries oxygen.

Abstract: A colored, corrosion resistant architectural material having improved corrosion-resistant properties wherein the material includes stainless steel which is coated with a tin and the tin coated material is post-treated with an oxidizing solution to remove the tin coating to expose a barrier which includes an alloy of chromium, iron and tin. The barrier exhibits excellent corrosion resistance especially with respect to chlorine and has a dark grey or earth tone grey color.

Abstract: After preliminary treatment of their surfaces, the parts are brought into contact within a solution containing, essentially, protons, phosphate anions and cations chosen from Ca.sup.2+, Sn.sup.2+ and Mn.sup.2+. The preliminary treatment results in the formation, on the surface, of a layer that comprises, per 1000 atoms, at least 150 atoms of free iron and from 5 to 150 atoms of sulphur, and has a porosity defined by an actual surface area to macroscopic surface area ratio of at least 20. According to an embodiment, these surface characteristics are obtained by nitriding in a bath of molten salts containing sulphur-containing species. According to a second embodiment, these surface characteristics are obtained by nitriding in a bath of molten salts followed by a conventional sulphiding operation. According to a third embodiment, these surface characteristics are obtained by depositing metal, followed by a conventional sulphiding operation.

Abstract: An improved salt and method of using such salt for conditioning scale on strip or sheet metal surfaces is provided. In more particular aspects, the invention provides an improved salt of alkali metal hydroxides and alkali metal nitrates which are used in their fused anhydrous form to condition scale on metal strip or sheet. The salt preferably contains from about 40% to about 70% potassium hydroxide, from about 20% to about 55% sodium hydroxide, and from about 2% to about 30% of an alkali metal nitrate. The salt is especially adapted to be sprayed onto a moving strip or sheet of metal as it passes a spray station, although it can also be used in conventional salt bath applications in which the salt is maintained in a fused condition in a tank, and the sheet, strip, bar, tubing or other form to be treated is immersed in the fused salt bath.

Abstract: Methods and apparatus for improving fretting resistance of zirconium alloy components formed into a shape for use in a nuclear reactor are disclosed in which at least a portion of the outer surface of a component is reacted with material selected from the group consisting of carbon, nitrogen, oxygen and combinations of the foregoing at a temperature below about 700.degree. C. to form a wear resistant layer on the surface of the component.

Abstract: A method for forming a carbide coating of Group IVA, VA and VIA transition metals and their alloys. The metal to be coated is heated in a bath of molten alkali or alkaline earth metal containing carbon. There is also provided a method for preparing a metal surface for carburization by heating the metal in a nitrogen-containing atmosphere.

Abstract: A furnace for cracking of hydrocarbons, comprising one or several tubes through which the hydrocarbons flow during intensive heating and subsequent cracking. The starting material for the process can be e.g. naphtha or propane, mixed with a small amount of steam. When gases flow through the tube or tubes in the furnace, its temperature is increased up to about 850.degree. C. In order to achieve this, the temperature in the furnace compartment is 1100.degree.-1200.degree. C., and the temperature of the gases in the tubes in the furnace can then exceed 1100.degree. C. The tubes are made from an alloy comprising 15-30 weight % chromium, 3-10 weight % aluminum, the remainder of the composition being mainly iron. This alloy allows significant extension of the possible duration of operation without exchange of the tubes. A further improvement can be achieved by the formation on the inner walls of the tubes of a layer of aluminum oxide, obtained by oxidation of the tubes before the furnace is first used.

Abstract: A wear-resistant titanium alloy containing titanium carbides which are crystallized and/or precipitated and are dispersed in the .beta.-phase matrix is disclosed. The alloy may further comprise .alpha.-phase and/or additional hard particles dispersed in the .beta.-phase matrix.

Abstract: A corrosion resistant stainless steel article is provided with a substantly uniform black oxide coating over the surface thereof, the article being formed from a steel alloy in martensitic structure which is treated in a boiling aqueous alkaline-chromate-oxidizing solution containing sodium hydroxide, sodium nitrate and sodium dichromate at a temperature in the range from about 230.degree. F. to about 260.degree. F. for 30 to 60 minutes.

Abstract: A process for fabricating synthetic materials, such as "atomic ceramics", by atomic alloying of a host material. Energetic modifier elements or species are introduced into the host matrix of a fluidic precursor material so as to obtain an engineered material characterized by a range of optical electrical, thermal, chemical or mechanical properties not exhibited by either the modifier or the precursor material. In this manner modified, layered, graded, doped and/or alloyed materials may be synthesized. Special emphasis is placed on a novel technique for the synthesis of optical fibers.

Abstract: A sterile surgical needle having a dark, non-reflective and non-flaking surface. The needle is produced by selecting an appropriately shaped needle having the desired degree of sharpness. The needle is treated to activate the surface and then immersed in a solution of sulfuric acid, potassium dichromate and water to form a dark, non-reflective, non-flaking surface. The needle is sterilized to produce a sterile surgical needle of improved visibility.

Abstract: A sterile surgical needle having a dark, non-reflective and non-flaking surface. The needle is produced by selecting an appropriately shaped needle having the desired degree of sharpness. The needle is treated to activate the surface and then immersed in a solution of sulfuric acid, potassium dichromate and water to form a dark, non-reflective, non-flaking surface. The needle is sterilized to produce a sterile surgical needle of improved visibility.

Abstract: The present invention is a method of rapidly and reproducibly checking the quality of zirconium base material welds and heat affected zones. In this method, weldment samples are immersed in an elevated temperature fused salt bath for a time period sufficient, at the bath temperature selected, to produce an essentially black oxide film in acceptable quality welds while producing a scaling oxide in unacceptable welds.

Abstract: A bath for treating a metallic workpiece so as to provide a surface finish thereupon includes a reagent adapted to react with the surface and an abrasive material. Relative agitational motion between the abrasive and the workpiece is provided and in this manner the abrasive promotes uniform reaction of the workpiece surface with the reagent so as to provide a uniform, deposit-free coating. Also within the scope of the present invention is a method for treating workpiece surfaces utilizing such a bath.

Abstract: Filaments are coated with MgO to create an effective diffusion barrier between the filament and the matrix in a metal matrix composite, thereby improving the strength and the service life of the composite.