Application of resource-saving extrusion technologies and an integrated approach to assessing the plasticity of metal parts in agricultural engineering

Abstract

Among the promising resource-saving technologies to produce parts with improved performance characteristics, the processes of volumetric plastic deformation of products occupy a prominent place. The research relevance is determined by the need to improve the mechanical properties of deformed metal, increase tool life, and produce high precision stamped products with an appropriate level of technological heredity. The study aims to create the required level of strain hardening and damage resistance of deformed metal and products of complex configuration, which will replace expensive steel grades with cheaper ones with similar service characteristics. To calculate the components of the stress tensor under non-monotonic loading, the anisotropic-strengthening body model is used. The study of theoretical and experimental findings suggests that cold combined extrusion methods should be used to manufacture parts with a flange, which can significantly increase the boundary dimensions and improve the technological heredity of the product. The study presents a methodology for determining the kinematic characteristics of plastic metal flow using analytical functions obtained from experimental studies of the motion of a continuous medium. The tensor approach was used to create a model of damage accumulation under non-monotonic deformation. The presented complex of calculations can be used to determine the stress state and the amount of the spent plastic deformation resource during non-monotonic volumetric deformation with a sufficiently high accuracy, without preliminary heating of the metal. Based on the information on the stress-strain state and the tensor model of damage accumulation, the ultimate forming of parts with a flange was estimated. The practical value of the research lies in the use of the proposed approaches to solve several technological problems of metal processing by pressure when the material undergoes non-monotonic plastic deformation under conditions of bulk stress