Recently, the grain boundary−intragranular nucleation of ferrite has received great attention seeking for the improvement of the toughness in the steel, specially when conventional austenite grain refinement techniques are not enough. This paper deals with some relevant aspects about the competitive process of allotriomorphic and idiomorphic ferrite transformations in a medium carbon vanadium-t...

Based on the results that the magnitude of the stabilization of retained austenite increases with increasing the amount of martensite transformed, it has been assumed that the martensitic transformation is accompanied with an increase in internal resisting stress which subsequently results in the stabilization of retained austenite. By simplifying this internal resisting stress to be a type of ...

Low-temperature bainite, obtained by the transformation of austenite at temperatures as low as 200oC for times as large as several days, has been reported to have extraordinary mechanical properties including the highest reported hardness of any bainitic steel. The unusual properties are a consequence of the fine scale of the microstructure, which contains bainite plates with thickness in the r...

Cementite dissolution in hypereutectoid steels containing Cr is analyzed using dilatometry combined with the consideration of the carbon content in the austenite. The results suggest that the austenite transformed from the mixture of ferrite and cementite can be approximated to have a carbon content corresponding to equilibrium with ferrite. The overall dissolution behavior of cementite is desc...

Superelastic NiTi (51.0 at.% Ni) specimens reinforced with 0, 10 and 20 vol.% TiC particles were deformed under uniaxial compression while neutron diffraction spectra were collected. The experiments yielded in-situ measurements of the thermoelastic stress-induced transformation. The evolution of austenite/martensite phase fractions and of elastic strains in the reinforcing TiC particles and the...

where k and h are the Boltzmann and Planck constants, respectively, W is the number of octahedral interstices around a single such interstice, ~F* is an activation free energy, r m is an activity coefficient and), is the distance betwe-en (002) austenite planes. <1'= 1exp(-wy/kT); Wy is the nearest neighbour carbon-carbon interaction energy in austenite. () is the ratio of the number of carbon ...

To study the effects of various types of precipitates and precipitate evolution behavior on austenite (size and phase fraction) in reduced activation ferritic/martensitic (RAFM) steel, RAFM steel was heated to various austenitizing temperatures. The microstructures of specimens were observed using optical microscopy (OM) and transmission electron microscopy (TEM). The results indicate that the ...

Fig. 1: Maps of the deviatoric strain of the B2 austenite along the vertical y axis (εyy) from x-ray diffraction analysis. The global displacements for these maps are shown in the upper left corner of each image. The dark lines illustrate the approximate location of the edges of the diamond strut. The red color indicates tensile strain whereas blue indicates compressive strain; note also the pr...

Purpose: of this paper is the effect of the soft annealing of initial microstructure of the 6Mn16 steel on the kinetics of the austenite formation during next intercritical annealing. Design/methodology/approach: Analytical TEM point analysis with EDAX system attached to Philips CM20 was used to evaluate the concentration of Mn, Ni and Cr in the microstructure constituents of the multiphase ste...