Showing papers on "Forging published in 1978"

Hot-forged ferroelectric ceramics of some bismuth compounds with layer structure

Abstract: The presintered layer structure bismuth compounds of PbBi2Nb2O9, Na0.5Bi4.5Ti4O15, PbBi4Ti4O15 and Pb2Bi4Ti5O18 are hot-worked by press forging under the maximum load of 200 kg/cm2 at a temperature of 1000°C to 1200°C. The reduction ratio of height is more than 70%. The well-oriented polycrystalline samples with an orientation degree of more than 0.8 can be obtained. The measured results of dielectric and ferroelectric properties are correlated with SEM observations and x-ray diffractions.

Forging of liquid and partially solid Sn-15 Pct Pb and aluminum alloys

Abstract: The possibility of producing simple shaped components from a liquid and partially solid initial charge material in a forging type operation was investigated. Ingots of Sn-15 Pct Pb alloy and aluminum alloys 6061 and A356 were heated to temperatures above the liquidus and in the liquid-solid range. The partially solidified charge materials were previously made in a continuous slurry producer. Sound flange shaped cup parts and unidirectionally solidified cylinders were produced in a 50 ton hydraulic press. Die thermal behavior was experimentally determined from thermocouples located at different distances from the metal-die interface. Measured maximum die temperatures were lower when the initial charge material was partially solid or when applied pressure was reduced. A one dimensional computer heat flow program was developed to simulate heat flow in the cylindrical parts and the steel dies. Correlation of computer predictions and measured temperatures were used to calculate values of the heat transfer coefficients at the metal-die interface prior to and after pressurization. The heat transfer coefficients increase by one order of magnitude or more upon application of 9.1 × 107 Pa pressure. Heat transfer coefficients prior to and after pressurization were 3.4 × 103 and 3.4 × 104 W.m-2.K-1, respectively, for a liquid and 8.4 × 102 and 3.1 × 104 W.m.-2.K-1 respectively, for a 0.5 volume fraction solid charge of A356 aluminum alloy.

Warm forging of connecting rod caps

Abstract: Rod end caps and the method of forming same comprising the steps of using a flashless, closed die set, a predetermined shape and volume billet, warm forging temperatures, and a unique ejector. The ejector pin defines part of the mold cavity when retracted, ejects the finished parts when extended, and locates new billets when in an intermediate position.

Method for making fine-grained Cu-Ni-Sn alloys

Abstract: Cu-Ni-Sn alloys are of commercial interest in applications which involve shaping by mechanical working of an alloy as well as in casting applications. Disclosed is a method which is particularly beneficial for casting and forging applications, i.e. applications which involve only limited amounts of working or none at all. The disclosed method allows the production of a fine-grained structure in a Cu-Ni-Sn alloy by a thermal treatment which calls for maintaining the alloy at three specified distinct temperature levels for specified time periods. The resulting fine-grained alloy may undergo further processing as may be beneficial, e.g., to develop desired levels of strength and ductility.

Stainless steel drill screw

Abstract: A drilling and tapping screw constructed from a 300 series stainless steel material which has the corrosive resistance of the high chromium high nickel content stainless steel while still being capable of drilling through carbon steel materials or the like. The product is constructed by forging the point at very slow forging speeds, resulting in a drill screw which is a predominantly martensitic structure at the drill point while predominantly austenitic in the shank and head regions.

Tool for isothermal forging

Abstract: A tool for isothermal forging is disclosed. The tool consists of two die halves, at least one of which consists of an assembly of individual components whose side facing the workpiece is provided with a thin electrically insulating layer. The assembly of the die half from individual components occurs following forming of the components by casting and/or forging, and machining of the formed components. The forming of the die halves from separate components makes it possible to adapt the components of the die half to the particular working conditions in an optimum manner. The provision of an insulating layer on the individual components reduces the risk of local welding and nonuniform temperature distribution during inductive heating.

Machine for noncutting metal shaping

Abstract: In a forging machine where the frictional work is reduced in the driving system at the main crankshaft and its support bearings, especially at the moment a forging force is applied. A rotary driven crankshaft is connected to a crank mechanism, which has a connecting rod connected to the driven crankshaft. The opposite end of the connecting rod is pivotally connected to an arm for driving the main crankshaft in an oscillatory rocking motion, which reciprocates the hammer means.

Production of nonrefined forged steel products

Abstract: PURPOSE: Raw material steel for forging is added with V, and after forging the products are subjected to a specificaly adjusted cooling, thereby producing high- strength, high-toughness forged steel products without using refining process. CONSTITUTION: Forging steel includes, C: 0.30 to 0.60%, Si<0.50%, Mn: 0.60 to 2.0%, V: 0.30 to 0.20%, sol Al: 0.02 to 0.06%, N: 0.008 to 0.02%, and if required Cr<0.50% or one or more of specific amount of S, Pb, Bi, Te, Se, Ce, and Ca, Mn%/C% being adjusted to more than 2. The steel material is, immediately after hot forging, adjustably cooled to a temperature just above the A 3 , at a cooling rate of 0.7 to 15°C/sec. After starting modification, the material is cooled to 500°C at a rate of 0.2 to 15°. Such cooling process hinders the growing of austenite granules, precipitating V carbide and V nitride in modifying period, which function as nucleus for ferrite modification to produce very fine structure of ferrite plus pearlite, thereby providing high-strength, toughness, and malleability to as-forged products without using refining process. COPYRIGHT: (C)1979,JPO&Japio

Process for the automatic manufacture of drop forging

Abstract: Apparatus for the automatic manufacture of drop forgings, particularly wrhes, from split-off and stamped workpieces comprises prebending means having a stationary bending jaw and a bending jaw which is movable in a horizontal plane, transfer means, and a power hammer which is disposed below the prebending means and has forging dies which are oppositely movable in a horizontal plane.

Method of manufacturing mechanical parts from metal scrap

Abstract: A method of manufacturing mechanical parts from the raw material of metal scrap such as shavings and turnings of castings and steel and press chips of steel, includes the steps of: preparing the metal scrap including shavings and turnings; forming a billet by pressing metal scrap; heating the billet to the forging temperature, whereby a satisfactory plasticity is given to the billet for plastic deformation of metal scrap in the succeeding process; and forming the heated billet into a forged workpiece by use of a semi-closed forging die. The shape of the billet is determined such that, in this forging step, the respective portions of the billet are subjected to plastic deformation having a given plastic deformation rate, whereby material flow sufficient to generate metallic bond at the respective portions is caused, and burred portions are formed on portions of the forged workpiece mainly subjected to extrusion press during die-forging.

Method of hot die isothermal dwell forging

Abstract: A forging compound particularly adapted for hot die dwell forging of titanium and its alloys comprises boundary layer particles (boron nitride or graphite) and a major quantity (more than 60% by weight) of vitreous components. The vitreous components comprise diboron trioxide and silica frit containing a metal oxide wetting agent. In a preferred form, the forging lubricant comprises about 14 to 25% by weight boron nitride particles, balance, vitreous components. The latter comprise about 60% to 75% by weight diboron trioxide, balance silica glass containing cobalt oxide wetting agent in an amount of 1.0 to 3% by weight of the vitreous components. All the foregoing ingredients may be dispersed in a coatable carrier preferably comprising a solvent, e.g., xylene, in which a resin binder is dissolved. A method of using the lubricant includes coating workpieces with the lubricant, heating the workpieces to forging temperature, and imposing forging pressure on the workpiece within an enclosed die for a dwell period to creep-flow the workpiece metal into conformity with the forging die.

Process for forging metallic nozzles

Abstract: A single step in the form of a heavy forward displacing forging operation is used to manufacture cylindrically bored ferrous-metal multiple diameter nozzles with an outside diameter of at least 22 inches, weighing at least 4,000 lbs. and possessing an exterior configuration comprising a round cylindrical base section of largest diameter with an outwardly-extending flange at one extremity, spaced second cylindrical section of smaller diameter, and an interconnecting and intercommunicating frusto-conical section.

Disk and Strip Forging for the Determination of Friction and Flow Strength Values

Abstract: For forging operations, process parameters, such as workpiece geometry, forging load, and material properties of the deforming body, can all be measured by well-established techniques. Interface friction, however, is a far more elusive quantity, yet its significant role in determining forging forces and mode of material flow is well-recognized. Three new techniques are proposed to enable friction determination during forging. The first of these permits friction measurement over a small but finite increment of deformation; the second, removes the controversy over measuring geometry changes of a barreling surface and, therefore, provides for increase measurement accuracy; the third technique extends measurement to forging under plane strain conditions and introduces a new approach to the problem. The use of forging to measure flow stress and provide stress-strain data for the material being formed is discussed briefly. Presented at the 32nd Annual Meeting in Montreal, Quebec, Canada, May 9–12, 1977

Sintering of coated briquette

Abstract: A method of making sintered powder metal parts which particularly includes a hot forging step, is disclosed. Selected powders of a predetermined particle size distribution, are blended and agglomerated by cold compaction into a preform. The preform or briquette is then coated with a thin shell of a chemically inactive radiation absorbing material, preferably graphite, under ambient conditions. The coated briquette is then sintered in a continuous through-put furnace with the temperature maintained at a level of at least 2000° F. and the part being subjected to the furnace heating for a period of 5-30 minutes. The sintered part may then be subjected to direct hot forging with the retained temperature of sintering utilizing the graphite coating as a die lubricant, or the sintered part may be cooled and then subsequently reheated for hot forging, again utilizing the retained graphite coating as a die lubricant. If hot forging is not to be employed, the graphite particles are removed such as by brushing so that sizing, machining or grinding may be carried out without the presence of the graphite coating.

J-Integral Approach to Fracture of Rotating Disk

Abstract: The J-integral has been used as a fracture criterion for elastic-plastic behavior of metals It may be pertinent to use the JIc concept for design or nondestructive inspection of rotating disks which have crack-like flaws and exhibit some amount of plastic behavior to fracture JIc for cracked rotating disks of rotor forging steel is determined experimentally and is compared with that obtained using compact specimens It is shown that prediction based on the compact tension tests agrees well with initiation of crack growth in rotating disks