Ductility and strength of previously deformed chromium steel in biaxial tension at low temperatures

Predicting the strain hardening characteristics of ageing alloys under combined loading

“…The specimens were prestrained by uniaxial tension (n 1 = ¥) to a plastic strain e z p 1 from 0 to 1.0%, and then uni-and biaxially loaded by axial force and internal pressure with different ratios between longitudinal and transverse principal stresses: n z 2 = =-¥ s s q / , 0, 0.5, 1, 2, ¥ (n 2 = -¥, 0, ¥ correspond to uniaxial compression, transverse tension, and longitudinal tension; n 2 = 0.5, 1, 2 correspond to biaxial tension). Experimental and data processing procedures were outlined in [2,[4][5][6]11]. The uniaxial loading tests were conducted to determine the compressional ( )that were used to plot the generalized stress-strain curve (s i versus e i ) to determine the generalized yield stress s iT (at e i = 0.2%) and its components s Z T and s q T (as functions of s iT and n 2 ) and to plot yield loci (s Z T versus s q T ) in the case of a plane stress state.…”

“…The dissolution of dislocations in reversely deformed alloys depending on alloying and thermomechanical preloading are studied in [17,19] in connection with the Bauschinger effect. However, there seem to be few or even no attempts to use the results of such studies to predict the mechanical behavior of structural metals with different preloading and reloading paths from their structural characteristics.One of the approaches to solving this problem for structural metals with mixed (isotropic and kinematic) strain hardening [4][5][6]8] is to examine the structural dependences of the parameters of yield loci-the radius and center shift under combined loading [1,2]. This approach is based on the possibility of determining, in the first approximation, the parameters of yield loci as functions of the compressive and tensile yield stresses of pretensioned metal, or as functions of the ratio of these stresses (a measure of the Bauschinger effect) [1,11].…”

“…One of the approaches to solving this problem for structural metals with mixed (isotropic and kinematic) strain hardening [4][5][6]8] is to examine the structural dependences of the parameters of yield loci-the radius and center shift under combined loading [1,2]. This approach is based on the possibility of determining, in the first approximation, the parameters of yield loci as functions of the compressive and tensile yield stresses of pretensioned metal, or as functions of the ratio of these stresses (a measure of the Bauschinger effect) [1,11].…”