The use of stress-relaxation measurements for investigations on the flow stress of α-iron

On high purity α-iron single crystals the temperature dependence of the flow stress is measured between ≈ 30 and ≈ 380 K by successive (small) tensile deformation steps at different temperatures. Stress-relaxation measurements are carried out in each deformation step. In analysing these measurements a method is developed for determining the stress dependence of the activation enthalpy and the preexponential factor in the Arrhenius equation rather directly. Characteristic differences for three temperature/stress regimes are observed.