Study of the Influence of the Main Parameters of “Rolling-ECAP” Process on the Stress-Strain State and the Microstructure Evolution Using Computer Simulation

Abdrakhman B. Naizabekov, Sergey Nikolaevich Lezhnev, Evgeniy Panin

2019

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DOI 10.1016/j.promfg.2019.12.074
Data confidence 85 high
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Abstract

The paper presents the results of computer simulation of the combined process, which combines longitudinal rolling and equal-channel angular pressing (ECAP). The simulation was carried out in the program Deform-3Dto assess the impact of the main parameters of the process on the stress-strain state. Analysis of the influence of various factors on the stress and strain state of the process showed that such factors as the junction angle of the matrix channels and the workpiece heating temperature have a significant impact on the distribution of stresses and accumulated deformation throughout the volume of the workpiece in the implementation of the combined process "rolling-ECAP". At the same time, the variation of the values of the friction coefficients and the lengths of the matrix channels within the permissible values does not play a significant role in changing the SSS parameters in this combined process. As a result of studying the microstructure evolution after modeling in the Simufact Forming program, it was found that the combined method "rolling-ECAP" allows to significantly grind the initial grain size. It is established that the influence of the workpiece heating temperature plays a significant role in the degree of grain grinding. In order to reduce the spread of values and alignment of grain size across the section, it is necessary to subject the workpiece to several deformation cycles. After the third pass, the average grain size difference between the central and surface zones is only 3 μm, which is much smaller than that after the first pass (7 μm). This allows us to talk about a fairly uniform study of the structure of the cross section of the workpiece.