Actual Problems in Machine Building 2016 No. 3

Актуальные проблемы в машиностроении. 2016. №3 Материаловедение в машиностроении ____________________________________________________________________ 363 THE INFLUENCE OF CYCLIC DEFORMATION ON THE BENDING STRENGTH AND THE DUCTILITY OF LOW-ALLOY STEELS Maksimov A. B. , Ph.D. (Engineering), Associate Professor, e-mail: aleksandrmks@yandex.ru Gulyaev M. V. , Ph.D. (Military), Associate Professor, e-mail: aladin58@mail.ru Erokhina I. S. , Senior Lecturer, e-mail: irina-kerchanka@yandex.ru Kerch State Maritime Technological University, 82 Ordzhonikidze str., Kerch, 298309, Republic of Crimea, Russian Federation Abstract In this paper we propose the explanation of the change of the impact toughness and elongation during cold deformation of cyclic plastic bending of plate steel 10Г2С1. It is known that when the cyclic strain curve the hardening is accompanied initially by a decrease in the viscosity and plasticity of steel, then there is a partial recovery, and in total strain more than (30-40)% further reduction. Under cyclic deformation by bending in the surface layer (thickness (1-1,5) 3 10   m. wide beam there are residual compressive stress, and the tensile residual stresses. Compressive stresses increase ductility and toughness of steel. Tensile stress – lower ductility and toughness. The increase in the density of individual dislocations leads to decrease of ductility and toughness. Then there is a cellular dislocation, which increases the viscosity and plasticity. The combination of the factors of increasing and decreasing the ductility and toughness of the steel makes this change in impact strength and elongation Keywords low alloy steel, cyclic bending, hardening, viscosity, elongation, wide beam.