Martensitic Transformation under Stress in Ferrous Alloys. Mechanical Behaviour and Resulting Morphologies

Abstract

Abstract. Tmnsformation plasticity deformation mechanisms are reviewed in the case of ferrous alloys. From experimental data, microstructural observations and numerical simulations the contributions of the different mechanisms are discussed and a schematic diagram of these evolution is proposed depending on the applied stresses and the test condition.

Considering Stress-Phase Transformation Interactions in the Calculation of Heat Treatment Residual Stresses

“…The variation of transformation plasticity with the progress of transformation has been found as linear for pearlitic and ferritic transformations of steels [I 1,121. For martensitic transformation, this variation is generally found to be nonlinear with a high slope at the very beginning of the transformation due to the orientation effect (mechanism 2) and to plastic accommodation (mechanism 1) and a decrease of this slope as the orientation effect decreases [5, 101. Moreover, the nonlinear relationship between transformation plasticity and the applied stress at given martensite contents has been clearly analysed [5]. The behaviour during bainitic transformation is found similar to the one during martensitic transformation as shown in some recent studies [13, 141.…”

Effect of tensile stresses on bainitic isothermal transformation

“…It is well established that when transformation occurs in the presence of stresses, the transformation kinetics, the mechanical behaviour as well as the morphology of the product phases are modified [1,2]. If those interactions between stresses and diffusion dependent or martensitic transformations are known and clarified, less results exist in the case of the bainitic transformation.…”

Metallurgical Phase Transformation and Behavior of Steels Under Impact Loading

“…[5][6][7] This form of plasticity contributes remarkably to the mechanical properties of this class of stainless steels by improving their ductility, strength, strain-hardening capacity, and delays the occurrence of necking. [8][9][10] Sachedv [11] studied the effect of residual austenite on the tensile behavior of a dual phase steel at temperatures between À 50°C and 187°C, suggesting that the ductility of dual phase steels can be further improved by optimizing the stability of the retained austenite. Authors [12][13][14] concluded that the rate of transformation of retained austenite and thus, its mechanical stability are the key factors that influence the work hardening behavior of TRIP-assisted steels.…”