Actual Problems in Machine Building 2017 Vol. 4 No. 1

Actual Problems in Machine Building. Vol. 4. N 1. 2017 Materials Science in Machine Building ____________________________________________________________________ 104 17. Канн Р.У., Хаазен П.Т. Физическое металловедение. Т. 3: пер. с англ. – М.: Металлургия, 1987. – 330 с. 18. Бернштейн М.Л. Структура деформированных металлов. – М.: Металлургия, 1977. – 431 с. THE EFFECT OF PRELIMINARY SCHEME OF DEFORMATION ON THE TOUGHNESS OF LOW ALLOY STEEL Maksimov A.B ., Ph.D. (Engineering), Associate Professor, e-mail: aleksandrmks@yandex.ru Yerohina 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 The influence of the scheme of pre-strain on cyclic bending on the value of impact strength low alloy steel 09Г2 when tested for impact strength. It is established that, if the bending pre-strain occurs in the same plane as the bending test impact strength, the decrease in toughness more than if these planes would be perpendicular. This difference is explained by the conditions of initiation and propagation of cracks in both cases. If the plane of bending coincide when pre-deformation and when tested for impact strength, the origin and development of cracks occurs in areas of tension and then occurs in the region of compression. With mutually perpendicular arrangement of these planes is the front for the initiation and propagation of cracks occurs in the compressed and stretched regions. When pre-deformation cyclic bending in the surface layers of the specimen having compressive stress, and in the Central and intermediate regions of tensile stress. Depending on what field will emerge and spread crack when testing the impact strength will depend on the magnitude of toughness. Keywords residual voltage, low alloy steel, plastic bending, impact strength, degree of a single strain, the number of bending cycles, the scheme of deformation