Plastic flow during longitudinal low temperature rolling

The technology of production of pro-shaped profiles of high precision by means of longitudinal low-temperature pro-rollers (Т def ≤ 0.1Т melt) of different materials such as steel, titanium, brass and nickel silver from the initial round billet. was experimentally studied. Rolling was carried out in one or more passes without intermediate heat treatments on a smooth barrel and in gauges formed by two, three and four rolls, the axes of which are located in the same plane. The plastic flow was studied along the circuit cross-sectional profile, including the contact surface with deforming tools - rolling rolls, as well as along the entire length of the deformation zone. Measurements of geometric dimensions were made with the tool microscope, the optical projector and the test machine. Instability and heterogeneity of the plastic flow of metal in the deformation zone of the deformable cross-sectional profile was experimentally established at longitudinal low temperature rolling of the round billet in one or several passes without intermediate heat treatments, regardless of the type of the material and the type of the deformation zone. The wave nature of plastic deformation in combination with localized hopping was discovered including surface contact with the deforming tool. Patterns of metal interaction with the deforming tool are uniquely associated with such indicators as rolling conditions, compression, the contact area with the metal deforming tool, the number of rolls forming a gauge. At multipass deformation all indicators of the plastic flow are discontinuous, and the discontinuity point coincides with the beginning of deformation in a subsequent pass. Results of the study are used in the development of technology and production of pilot batches of high precision shapes of rectangular, segmental, triangular and square cross-sections.