Nauka i Tehnika (Oct 2015)

HEAT GENERATION AND RESISTANCE TO DEFORMATION OF STRUCTURAL STEEL

  • A. E. Moyseychik,
  • Yu. V. Vasilevich

Journal volume & issue
Vol. 0, no. 5
pp. 33 – 38

Abstract

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The purpose of this paper is to determine dependence between heat generation and resistance to deformation of structural steel.It has been assumed on the basis of the represented data that in the course of deformation of structural steel physicochemical interactions of dislocations and impurity atoms occurring in the slip bands result in heat generation and temperature increase of product surface. Interdependence of heat generation and elastic-plastic deformation has been experimentally proved by set of experiments on low-carbon steel plate extension. In the case of deformation its intensity and rate are considered as main factors that determine local material heating in the pre-fracture nucleus and temperature directly exerts its influence on diffusion processes and changes in physical and mechanical characteristics of the material in the pre-fracture nucleus. The obtained average heating temperature for the pre-fracture nucleus is equal approximately (20–90)°С for low-carbon steel ВСт3сп while using quasi-static extension. The paper presents data pertaining to steel plate deformation that point to the fact that elastic-plastic deformation is accompanied by deformation heat generation and a crack initiation is caused by thermo mechanical process. Heat is formed in the slip bands and their direction corresponds to the maximum shearing stresses. Surface temperature in the zone of crack initiation has reached 88 °С in the pre-fracture stage. The Davidenkov-Spiridonova formula has been derived while using a concept of "surface energy" and Laplace's formula. This formula makes it possible to determine resistance to deformation of a stretched round steel rod in the stage of neck formation. The paper shows formula’s dependence on the deformation heat generation.

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