Research of the Influence of the Scheme and Modes of Pressing Steel and Cast Iron Chips on the Energy-Power Parameters of the Briquetting Process

The paper presents the results of an experimental study of the process of hot briquetting of fine-grained ferrous metal waste in a mold with a movable matrix. It has been established that in order to achieve the required density of finished briquettes of 90–95 % (one of the main quality criteria for modern metallurgical production), in the temperature range of hea-ting the charge of 700–850 °C, the pressing pressure reaches values of 470–500 MPa. The use of molds with a movable matrix ensures reduction in pressure and pressing force of ductile low- and medium-carbon steels up to 45 %, high-carbon, low ductility and difficult to deform - up to 35 %, cast iron – up to 25 %. The specific work of deformation (energy costs) when hea-ting waste ferrous metals to temperatures of incomplete hot deformation is reduced by 2.3–2.5 times. Compared to briquetting in a fixed matrix at the same temperatures, the specific work of deformation is reduced by 15–20 %. The process of deformation compaction of a discrete porous body occurs with minimal impact of lateral contact friction forces, since the compaction front (compacted chip layer) moves together with the matrix in the same direction with minimal relative displacement of the friction surfaces. The nature of deformation compaction and the level of resistance to deformation depend on the initial state of the material: the higher the plasticity of the metal, the more intense the compaction density increases; the higher the initial density and yield strength, the greater the pressing pressure must be applied to achieve the same density value. Fine additives of metallic or non-metallic origin fill the voids between larger fractions of chips and thus increase the initial compaction density and the pressure gradient as density increases.