EFFECT OF HYDROGENATION TEMPERATURE AND TENSILE STRESS ON THE PARAMETERS OF THE COMPLETE DEFORMATION DIAGRAM FOR STEEL 09G2S
Hydrogen concentration in the sample material depends on its environmental content, external pressure, temperature, surface condition, and testing time. All other things being equal, increasing temperature increases the diffusion coefficient and, consequently, hydrogen concentration in the metal. This, in turn, changes the mechanical properties of the material. The paper considers the principal possibility of determining the parameters of this process within the method of complete deformation diagrams. By changing the parameters of the diagram of the hydrogenated metal, a conclusion is made about the changes in its strength, plasticity, and crack resistance. The approach is illustrated by the results of testing samples of the structural 09Г2С steel, widely used in mechanical engineering. It has been found that the increasing temperature of hydrogenation reduces the strength and ductility of the steel and increases crack resistance. Thus, it is experimentally proved that the parameters of the falling branch of the complete diagram are sensitive to hydrogen concentration in the steel. The changes in the mechanical properties of the structural steel caused by the action of hydrogen are qualitatively similar to those caused by cyclic loading. In this regard, it is concluded that degradation processes of different natures can be studied on a common methodological basis. The parameters of the falling branch of the complete deformation diagram can serve as the representative parameters of these processes.