Analysis of the mechanical response of materials used in design for highly stressed components

In this paper both the mechanical properties and responses of materials usually used in engineering for design and manufacture of highly stressed components were considered. Between the materials used for the aforementioned purposes are considered the following steel alloys: 30CrNiMo8, 20MnCr5, 51CrV4. Investigated mechanical properties of the materials were ultimate tensile strength, yield strength and modulus of elasticity, while in the area of mechanical responses were explored / tested creep behaviour and fatigue of the considered materials. In general, all of the responses are presented in the form of stress-strain curves, creep curves and S-N curves (maximum applied stress versus the number of the cycles to failure). Mechanical properties were tested at different temperatures, creep behaviour was investigated at different temperatures when material was subjected to stresses at prescribed percentage of yield strength while fatigue of the considered materials was investigated on smooth unnoched specimen for prescribed maximum uniaxial stress and for prescribed stress ratio. In addition, all of obtained data were analysed and compared regarding the type of used materials. (paper)