[en] The predictability of the tensile mechanical behaviour was studied by the authors on the stainless steels outside the range of proportionality by the use of different phenomenological constitutive equations. Some of them, of the type σ = σ(epsilonsub(p)), where σ = true stress and epsilonsub(p) = true plastic strain, involve only one independent variable, whereas others of the type σ = σ(epsilonsub(p),epsilon), where (epsilon) = true strain rate, took into account two dependent variables. The experimental data were obtained from solution annealed AISI 310 steel samples tested at different temperatures between 293 and 1173 K and for two strain rates, 1.2.10^-3 and 2.8.10^-1 s^-5. Analysis of the results showed the good fitting of Ludwigson's law for the equations with one independent variable only, whereas for the equations with two independent variables that of Matteazzi-Petrone-Piatti follows the experimental results very well at room temperature where the rate processes are important. (author)

[en] The authors have performed an experimental determination of tensile stress-strain curves for different strain rates (4.67 x 10^-₅, 4.67 x 10^-₂ s^-₁) and for a variety of temperature conditions (773-1073 K) of AISI 316H stainless steel (annealed conditions) and also a computer analysis of the experimental curves using a fitting program which takes into consideration different constitutive relations describing the plastic flow behaviour of the metals. The results show that the materials tested are clearly affected by strain rate only at the highest temperature investigated (1073 K) and that the plastic strain is the more significant variable. Of the constitutive equations considered, Voce's relation gives the best fit for the true stress-time-strain curves. However, the Ludwik and Ludwigson equations also provide a description of the experimental data, whereas Hollomon's equation does not suitably characterize AISI 316H stainless steel and can be applied with some accuracy only at 1073 K. (author)

[en] A study is reported of uniaxial tensile properties over a wide temperature range (293-1173 K) and at different strain rates between 4x10^-5 to 4x10^-2 s^-1 for a high manganese content austenitic steel (Fe-17Mn-10Cr-0.1C) which is an alternative to AISI 316 stainless steel in the material selection for the conceptual tokamak fusion designs. The behaviour of this alloy is similar to that of the other high manganese steels, including a strain induced γ(fcc)->element of(hcp) martensitic transformation which considerably increases the strain hardening rate and leads to a maximum in ductility near 470 K. Moreover, non-linear statistical analysis of the true stress-true strain data, fitted to several constitutive equations, shows that the best description of plastic flow is given, for the present material, by the Ludwigson law (1971) or by the Matteazzi-Petrone-Piatti law (1982) if the strain rate effect is also considered. (orig./GG)

[en] The behaviour of AISI 310 stainless steel during monoaxial tensile tests is studied in this paper. We begin by examining the mechanical characteristics over a wide range of temperatures (293-1173 K) for two different cross-head velocities (3.33 x 10^-7 ms^-1) and find them to be in good agreement with those already reported in the literature. (orig.)

[en] A large collection of tensile stress-strain curves for different strain rates and for a variety of temperature conditions (293 - 1073 K) (annealed conditions) is examined. A numerical analysis of the stress-strain data is performed, using a curve fitting program and taking into account the following constitutive equations, which describe the macroscopical mechanical behaviour of the metallic materials. (orig./HP)