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The article investigates the effect of combined thermomechanical processing, including pre-heat treatment and radial-shear rolling on the brass microstructure evolution and the microhardness change. The microstructure analysis of heat-treated samples according to various modes showed that the most optimal heat treatment before radialshear rolling for L63 brass is annealing at a temperature of 500 °C. As a result of combined thermomechanical processing, a gradient structure was obtained, so in the resulting rods with a diameter of 16 mm in the surface layer, a structure with an average grain size of 9 μm was obtained. In rods with a diameter of 12 mm, a fine--grained, equalgrained structure of 3 µm was obtained in the surface layer. [ABSTRACT FROM AUTHOR]

Copyright of Progress in Physics of Metals / Uspehi Fiziki Metallov is the property of G.V. Kurdyumov Institute for Metal Physics, N.A.S.U and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents an overview of the latest trends in the development of severe plastic deformation (SPD) using rolling methods. From many scientific works, it is known that severe plastic deformation provides intense grain grinding up to ultrafine and nanosized grains during multi-cycle deformation. It is also possible to obtain a uniform or gradient grain distribution over the cross-section of the workpiece. During SPD processes, the strength parameters can be increased several times. Of all the methods considered, asymmetric rolling has become the most widespread owing to its simple implementation in production conditions. Most of the known methods and devices for asymmetric rolling are designed for deformation in rolls with a smooth barrel, while the use of rolls with a relief surface allows the processing of metal to obtain a higher level of equivalent strain. Ensuring a high asymmetry level when rolling in relief rolls allows, in addition to the development of shear strain in two transverse directions (height and width), it also provides an additional level of shear strain in the longitudinal direction. In addition to the speed asymmetry, the rolling scheme in relief rolls is also suitable for the implementation of geometric asymmetry when one of the relief rolls has a reduced or increased diameter while maintaining the relief geometry on the roll surface. [ABSTRACT FROM AUTHOR]

The paper presents the results of the conducted experiments confirmed not only the possibility of processing bar scrap from stainless metals to produce a marketable product, but also confirmed the possibility of obtaining highquality bars with a gradient fine-grained structure and an increased level of mechanical properties. In the course of the research conducted on deformed bar scrap in the form of pins from 12X18N9T austenitic stainless steel at the radial-shear rolling mill the microstructure of two different types was obtained: on the periphery - equiaxed ultrafine- grained structure with a grain size of 0,4 – 0,6 μm; in the axial zone - oriented striped texture. This discrepancy in the structure of the peripheral and axial zones, together with the results of microhardness measuring across the cross section of samples with a total degree of deformation of 44,4 %, indicates the gradient nature of the formed microstructure. [ABSTRACT FROM AUTHOR]

The cross rolling is the one of most perspective method of refinement microstructure metals by severe plastic deformation method. This method gives ability to get the long length billets. However, deformation and trajectories of the metal is very heterogeneous across the section of the rolled piece. This paper presents the finite element method (FEM) simulation of hot cross rolling and experimental study of the effect of the cross rolling on a different threeroll mills on the microstructure of ordinary structural alloy steel, stainless steel and technical copper in different zones of the bar. Analysis showed significant structure refinement in all cases. The best result was achieved on the stainless steel, and shown the formation of equal-axis ultra-fine-grain structure on the bar periphery. [ABSTRACT FROM AUTHOR]