Stability of retained austenite in TRIP-assisted steels

Abstract

A theory is developed for the quantitative representation of the strain induced transformation of retained austenite in low alloy, TRIP-assisted steels of the type developed for the automobile industry. It is possible, therefore, to calculate the fraction of austenite as a function of the plastic strain, chemical composition, deformation temperature and the starting amount of austenite. The effect of composition and temperature is expressed through the free energy available for transformation. Good agreement has been obtained with published experimental data. The model can be used to investigate the stability of the austenite during plastic deformation.MST/5936

Tensile Ductility of Nanostructured Bainitic Steels: Influence of Retained Austenite Stability

“…In an attempt to quantify the relationship between retained austenite stability and tensile ductility, the results were represented as per the following relationship [24]:…”

Carbide-Free Bainite: Compromise between Rate of Transformation and Properties

“…The constant k 1 has the value 0.002017 mol J À1 . [45] Figure 3 shows that percolation is lost when the elongation is approximately 15 pct. …”

“…Some of this will decompose to martensite on cooling; the retained fraction V c 0 = 0.24 was calculated using the Koistinen and Marburger equation. [44] The decomposition of the retained austenite as a function of plastic strain was then calculated using a published model, [45] which has recently been shown to be the optimum method for such calculations. [46] It is based on the equation…”

Properties of fine-grained steels generated by displacive transformation

“…It is now possible to estimate the change in the austenite content as a function of plastic strain and the driving force for martensitic transformation in TRIP steels [25]. Fig.…”