ПРО МОЖЛИВІСТЬ ПРОГНОЗУВАННЯ МЕХАНІЧНИХ ВЛАСТИВОСТЕЙ ХОЛОДНОДЕФОРМОВАНИХ МЕТАЛОВИРОБІВ ЗІ СТАЛЕЙ ПЕРЛІТНОГО КЛАСУ

Abstract

In accordance with the latest global trends and modern needs of hardware factories, the demand for wire rod made of pearlitic steels has significantly increased, which can undergo cold plastic deformation with large degrees of reduction and is intended for the manufacture of various commercial products (cold-worked reinforcement, reinforcing ropes, spring wire, steel cord, wire for high pressure hoses, construction fiber, etc.). The most promising direction for increasing the strength class of hot-rolled steels is strain hardening during cold plastic deformation. The structure of cold-worked steels has a more uniform distribution over the cross-section, in contrast to thermally hardened ones, which in the latter case are characterized by annular structural zones formed due to different mechanisms of austenite decomposition. In a number of cases, structural heterogeneity causes instability of the mechanical properties of rolled steel, therefore, there is currently no alternative way to strain hardening. The manufacture of high-strength cold-worked metal products is a complex process and depends on the quality of the wire rod. If the cold-worked hardware does not meet the requirements of the normative documentation for the strength class, then it is no longer possible to ensure the correction of this defect using heat treatment. In this regard, scientific and practical interest has arisen to determine the possibility of creating a method for predictive determination of the mechanical properties of cold-deformed metal products made of pearlitic steels. The features of the influence of cold plastic deformation by on the formation of the strength class of pearlite grade steels with a carbon content of 0.7…0.9 % are considered It is established that the temporary resistance to fracture, at the known parameters of structure and carbon content, lends itself well to mathematical calculations and allows to create predictive models. According to the results of the research, a computer program was created that allows to automatically calculate the energy parameters of drawing and determine the tensile strength of the wire after depending on the total relative compression, parameters of the structure of wire rod and the carbon content in the steel.