Abstract: A variable rate quench system allows the cooling of a heated workpiece to be controlled more closely. A liquid quenchant used in the system has an initial temperature, density and heat extraction index. The system comprises a first tank containing the liquid quenchant and to receive the workpiece and a second tank communicated to the first tank. The first tank has a means for agitating the liquid quenchant around the workpiece and a supply of make-up liquid quenchant communicated thereto. The second tank has a slurry of a non-liquid solid phase quenchant modifier and a means for selectively controlling addition of the slurry to the first tank. A real time data acquisition system acquires and analyzes temperature, density and agitation rate of the liquid quenchant, calculates an instantaneous heat extraction index of the liquid quenchant and compares the difference between the calculated index and a predetermined ideal index. Corrective action to minimize the difference is then taken.

Abstract: A method of cooling section steel, particularly sectional steel girders, from rolling heat, wherein, prior to a final air cooling, a water cooling process is carried out in such a way that section steel portions with material concentrations are cooled at outwardly projecting portions of the steel sections over a width of application and a duration of application which are variable and subject to a predetermined cooling strategy supported by a process computer to a value which is at least still slightly above the transformation temperature Ar1.

Abstract: The present invention provides a highly corrosion-resistant alloy used as a boiler tube in equipment the energy source of which is obtained by burning fossil fuel or waste, a steel tube for which the alloy is used, and a process for producing the steel tube. The alloy comprises up to 0.05% of C, 1.0 to 2.6% of Si, 0.02 to 1.0% of Mn, 20.0 to 28.0% of Cr, 18.0 to 30.0% of Ni, up to 4.0% of Mo, up to 0.05% of Al, 0.05 to 0.30% of N and the balance Fe and unavoidable impurities. Furthermore, the present invention also provides a multilayer steel tube having the alloy as a liner material and a standardized boiler tube as a base layer material, and a process for producing the multilayer steel tube.

Abstract: A coil spring made of an oil-tempered steel wire with internal hardness of more than Hv 550 in cross-section, the surface hardness of the oil-tempered steel wire being determined in an extent between Hv 420 in a minimum value and hardness defined by subtraction of Hv 50 from the internal hardness in a maximum value.

Abstract: The invention relates to free-machining steels which do not rely on lead as a means of enhancing machinability. Instead, the steels of the invention employ concentrations of tin at ferrite grain boundaries to replicate a role of lead, which the inventors have discovered, in enhancing machinability. This role is to cause an embrittlement at the localized cutting zone temperatures by changing the fracture mode from transgranular to intergranular at those temperatures. The invention's use of concentrations of tin at the ferrite grain boundaries of the steel permits the machinability-enhancing effect to be obtained while employing bulk tin contents below the levels at which hot tearing becomes problematic. The invention improves over lead-bearing, free-machining steels in that the machinability-enhancing embrittlement produced by concentrating tin at the ferrite grain boundaries is both controllable and reversible.

Abstract: A method for manufacturing reduced iron briquettes, wherein reduced iron obtained by a direct reduction method is made into briquettes using a briquette machine, and whereafter the hot briquettes are subject to gradual cooling at a cooling rate in the range of 150.degree. C. to 250.degree. C. per minute using water spray. The reduced iron briquettes thus obtained are (a) less prone to breakage break during storage and transport; (b) less prone to degeneration into powder accompanying such breakages etc.; and (c) also display an excellent degree of metallization. Hence, the loss in weight during storage and transport can be reduced, and the harmful effects caused by dust to the transport vehicles, ships, loading/unloading equipment, and operators of the same can be reduced. Also, since the number of breakages is reduced, there is also a reduction in the amount of any re-oxidation of the reduced iron which tends to occur at newly exposed faces, whereby a product of more consistent quality can be obtained.

Abstract: A workpiece is heated by first forming an ionized gas plasma around the workpiece. A positive potential is applied to the workpiece to accelerate electrons from the plasma into the workpiece. The workpiece is uniformly surface heated by the energy directed into the workpiece by the electrons. The workpiece is cooled by providing a flow of a pressurized liquid material such as carbon dioxide having a triple point. The liquid material is expanded through a nozzle to form solid particles that contact the surface of the workpiece and remove heat from it by subliming.

Abstract: A method of cooling steel sections which are hot from rolling by means of shock-like cooling following the rolling process so as to form a martensitic surface layer, and by subsequently autogenously tempering this surface layer by means of core heat to obtain a tough-resistant structure with an austenitic remaining cross-section, wherein the method is used in connection with types of steel which, with uncontrolled cooling in air, would directly transform from the austenitic phase into martensite because of their alloying elements from the group Cr, Mn, Mo, Ni and other suitable elements.

Abstract: A method of quenching a metal object having steps of: (a) providing a liquid coolant having a temperature from about 100.degree. F. to about 180.degree. F. and containing about 0.01 to about 0.1 standard cubic feet of carbon dioxide gas per gallon of water dissolved therein; and (b) spraying the liquid coolant on the metal object to quench the metal object.

Abstract: A process for selectively hardening a forged track chain link has the following steps. A forged track chain link having a pad portion, a rail portion, a first side portion and a second side portion, is provided. A quench tank is provided and adapted for spraying one or more of the track chain link portions with a quenchant at a controlled amount of quenchant flow rates, quenchant pressures and quench times. One or more of the track chain link portions are sprayed with the quenchant at a controlled amount of one or more of a plurality of quenchant flow rates, a plurality of quenchant pressures and a plurality of quench times. The pad and rail portions are simultaneously hardened to predetermined respective hardnesses.

Abstract: Thermal insulating gaseous blankets, generated by contact of a quench liquid with a hot metal workpiece, are displaced from downwardly directed surfaces by sequentially elevating the workpiece, at points about its periphery, so as to promote migration of the trapped gas across such surfaces. The improved heat transfer that results increases the levels of hardness and strength exhibited by the treated workpiece.

Abstract: The invention provides a process and apparatus for producing a quench gas mixture for increasing the cooling rate of an article. The quench gas mixture is produced by introducing helium gas into the bottom of a vessel containing a cryogenic liquid. Heat is transferred directly from the helium gas to the cryogenic liquid as the helium bubbles rise through the liquid to the surface. The resulting cryogenic vapor mixes with the helium gas in the ullage space at the top of the vessel, and the gas mixture is taken off from the ullage space and supplied to a cooling process.

Abstract: A method for quenching hot metals especially iron steel or copper with a quenching fluid comprising a major proportion of an organic phosphate ester. The preferred esters are trialkyl phosphates and tri(alkyl phenyl) phosphates. The quenched article may exhibit improved anti-wear properties.

Abstract: Ultrahigh carbon steels with superplastic properties are produced by heating a steel containing ferrite and carbide phases to a soaking temperature approximately 50.degree. C. above the A.sub.1 transformation temperature, soaking the steel above the A.sub.1 temperature for a sufficient time that the major portion of the carbides dissolve into the austenite matrix, and then cooling the steel in a controlled manner within predetermined limits of cooling rate or transformation temperature, to obtain a steel having substantially spheroidal carbides. New alloy compositions contain aluminum and solute additions which promote the formation of a fine grain size and improve the resistance of the carbides to coarsening at the forming temperature.

Abstract: A process for producing low-cost atmospheres suitable for decarburize annealing carbon steels from non-cryogenically generated nitrogen containing up to 1.54 residual oxygen by catalytically deoxygenating a non-cryogenically generated nitrogen stream at low temperatures with a hydrocarbon gas and mixing the deoxygenated stream with an economical amount of hydrogen prior to introduction into the furnace for annealing. The process includes the use of 1) hydrocarbon gas to convert residual oxygen to a mixture of carbon dioxide and moisture at low temperatures and 2) mixing the deoxygenated stream with a sufficient amount of hydrogen to maintain a pH.sub.2 /pH.sub.2 O ratio of at least 2 in the furnace.

Abstract: A high strength, high toughness Cr-W-V ferritic steel composition suitable for fast induced-radioactivity (FIRD) decay after irradiation in a fusion reactor comprises 2.5-3.5 wt % Cr, 2.This invention was made with Government support under contract DE-AC05-840R21400 awarded by the U.S. Department of Energy to Martin Marietta Energy Systems, Inc. and the Government has certain rights in this invention.

Abstract: A water box is used to cool hot rolled products in a rolling mill. The water box includes a base structure supporting a removable manifold, and a plurality of nozzles removably mounted on and in fluid communication with the manifold. The nozzles are lined with inserts which may be replaced when worn. The manifold is reversible end to end, as are the nozzles, thus enabling the water box to be used on either of two parallel rolling lines.

Abstract: A high-strength, damage-resistant rail characterized by essentially consists of 0.60 to 0.85 wt. % of C, 0.1 to 1.0 wt. % of Si, 0.5 to 1.5 wt. % of Mn, not more than 0.035 wt. % of P, not more than 0.040 wt. % of S, and not more than 0.05 wt. % of Al, a balance being Fe and indispensable impurity. The rail comprises corner and head side portions having a Brinell hardness H.sub.B of 341 to 405 and a head top portion having a hardness which is not more than 0.9 of the Brinell hardness of the corner and head side portions.

Abstract: A flat spring hose clamp having an improved resistance to brittle fracture and a method for manufacturing the same are disclosed, the hose clamp being made of a steel having a steel composition consisting essentially of, by weight %:C:0.30-0.70%,Si: 0.70% or less,Mn: 0.05-1.00%,P: 0.030% or less,S: 0.020% or less,Cr: 0.50-2.00%,Mo: 0.10-0.50%,Nb: 0.005-0.100%,sol. Al: 0.10% or less,N: more than 0.0020%, but not more than 0.015%,Ti: 0-0.10% and/or B: 0-0.0020%,and a balance of Fe and incidental impurities, and the steel possessing a uniform bainite structure.

Abstract: A series of controlled quenching of elevated temperature steel work pieces includes locating hot work pieces on a support at distances from one another sufficient to avoid slack quenching and subjecting the work pieces to a forced draft at a speed which results in consistent uniformity of hardness and uniformity of grain size of which about 10 MPH is exemplary, and an apparatus therefore which provides two pass cooling so that minimum horsepower is used and environmental degradation is avoided.

Abstract: Increased cooling rate of an article heated to an elevated temperature is achieved by flowing an inert gas mixture of helium and another inert gas over the article under conditions of turbulent flow.