Uniaxial fatigue, creep and stress-strain responses of steel 30CrNiMo8

The choice of individual material for industrial application is primarily based on knowledge of its behavior in similar applications and similar environmental conditions. Contemporary design implies knowledge of material behavior and knowledge in the area of structural analysis supported by large capacity computers. Bearing this in mind, this paper presents and analyzes the experimental results related to the mechanical properties of the material considered (30CrNiMo8/1.6580/AISI 4340) at different temperatures as well as its creep and fatigue behavior. All experimental tests were carried out as uniaxial tests. The test results related to the mechanical properties are presented in the form of engineering stress-strain diagrams. The results related to the creep behavior of the material are shown in the form of creep curves, while the fatigue of the material is shown in the form of stress &#8211; life (<i>S</i> &#8211; <i>N</i>) diagram. Based on these experimental results, the values of the following properties are determined: ultimate tensile strength (<i>&#963;</i>_<i>m</i>,20 = 696 MPa), yield strength (<i>&#963;</i>_0.2,20 = 355.5 MPa), modulus of elasticity (<i>E</i>_,20 = 217 GPa) and fatigue limit (<i>&#963;</i>_<i>f</i>,20,<i>R</i> = 280.4 MPa). Results related to fatigue tests were obtained at room temperature and stress ratio <i>R</i> = -1.