Energy-power characteristics when drawing a trimetal billet

A procedure for calculating energy-power characteristics while drawing a trimetal billet is proposed. Stresses in its single layers and total drawing stresses are determined. The optimal geometry of a drawing tool which accounts for key parameters of the production process is revealed.     

Production of continuous-cast blanks for rod and wire drawing at KUZOTsM

KUZOTsM has developed a highly profitable process for production of wire from many alloys; this process includes production of a continuous-cast blank of small cross section, which provides for a significant reduction in the production cycle and reduces metal loss through avoidance of hot working processes (rolling or extrusion). Implementation of this trend will lead to a substantial improvement in product yield and other production performance indicators, while maintaining quality of the end product at an appropriate level.     

Energy and force conditions of hydrostatic pressing of blanks from powder materials

Conclusions An examination is made of the hydrostatic pressing of metal powders. The total work done in this process is made up of six components. Their determination and methods of calculating them are described. Equations are proposed for calculating the work done in overcoming friction in the gland of the hydrostatic pressure vessel plunger. The equations allow for the variation of the coefficient of friction in the gland, which is a function of pressure in the vessel. Energy expenditure in hydrostatic pressing determined by calculation is in accord with experimental data. This shows that the equations proposed can be employed for choosing plant in the development of new technological processes for the production of parts from metal powders by hydrostatic pressing.Translated from Poroshkovaya Metallurgiya, No. 6(222), pp. 32–36, June, 1981.     

Production of hard-alloy blanks for very small tools

Conclusions A study was made of the character of flow of plasticized hard-alloy mixtures in the extrusion of blanks ranging from 100 to 1000 in diameter. It was established that the optimum flow rates, resulting in sound blanks for hard-alloy tools, are 130–150 and 230–250 mm/min, respectively, for mixtures plasticized with a solution of SR in benzine and paraffin wax.Translated from Poroshkovaya Metallurgiya, No. 2 (110), pp. 98–100, February, 1972.     

Forming of tailor-welded blanks

Beginning in 1992, tailor-welded blanks (TWBs) were used in the United States automotive industry to consolidate parts, reduce tolerances, save weight, and increase stiffness. This business is expanding rapidly; more than $500 million of annual TWB sales are expected by 1997. Welds in steel are generally stronger than the base material, such that weld failure by preferential localization is not a critical issue. However, the forming characteristics of TWBs must be understood in order to design and produce high-quality parts with reasonable production and tooling costs. Three formability issues were addressed in this study: the intrinsic ductility and relative formability of three weld types (CO₂ and Nd:YAG laser welds and mash-seam welds with and without mechanical postweld processing); the value and correspondence of mechanical tests to each other and to press performance; and the prediction of the forming behavior using the finite element method (FEM). Two failure modes for TWBs were identified. While the local ductility of welds can differ greatly, little difference in press formability was measured among the weld types. More important than weld ductility are the changed deformation patterns which depend on the differential strength but depend little on local weld prop-erties. Finite element method (FEM) simulations of dome tests and scale fender-forming operations show good agreement with measurements, as long as boundary conditions are known accurately. The importance of weld-line displacement is discussed and several simulations are compared with ex-periments. F.I. Saunders, Formerly Graduate Research Associate, Department of Materials Science and Engineering, The Ohio State University     

Selection of powders for the production of porous blanks

Summary An analysis is made of experimental data on the relation between the porosity, particle size, filtration fineness, and coefficient of permeability of porous materials. A formula is derived for determining the coefficient of permeability from known values of porosity and particle size.Translated from Poroshkovaya Metallurgiya, No. 11 (47), pp. 9–13, November, 1966.     

Simulation of the shaping of blanks for large-diameter pipe

An analytical method is outlined for calculating the bending parameters of thick sheet (thickness up to 40 mm) used in pipe production: the size and shape of the punch-blank contact zone; the elasticity coefficient of the blank and its residual surface curvature; the maximum force of the punch at different stages of stepwise shaping on a press. At all stages of the process, the model of an elastoplastic medium is employed. The results may be used in developing production technologies for large-diameter steel pipe used in pipelines.