Secondary recrystallization of oxide dispersion strengthened ferritic alloys

The recrystallisation behaviour of two Oxide Dipersion Strengthened ferritic alloys is investigated in the range of temperature from 750 to 1470°C. Recrystallisation temperature and grain morphology are discussed in relation to the cold-process used and their cold-work level. Different recrystallised morphologies of grains are observed at different temperatures, which seem to be related to the occurrence of different recrystallisation mechanisms

Phases transformation textures in steels

Low-carbon steels used for deep-drawability applications have properties which depend greatly on their crystallographic texture. It is therefore important to control the texture evolution during the thermomechanical processing. Until recently, little attention has been paid on the understanding of the textures formation after hot-rolling, which are produced by phase transformation, although it is recognised that they have an effect on the development of the texture in the further process (cold rolling and annealing). Indeed, one of the main difficulties consists in the measurement of texture above ambient temperature, in the austenite range. In the present work, EBSD technique is employed on a low-C steel and a method is proposed to determine local austenite orientation thanks to martensitic one, even if there is no residual austenite in the steel. The orientation relationships between the austenite phase and each of its product phases, here martensite and polygonal ferrite, are analysed and compared. Common Kurdjumov Sachs variants are detected for both phases. Variations in the intensities of these variants are also detected and could be due to the different phase transformation mechanisms, diffusion or shear

Effets des procedes de mise en forme sur les textures et les proprietes de traction des alliages ferritiques renforces par dispersion d'oxydes

Communication to : 1992 Powder Metallurgy World Congress, 21-26 juin, 1992, San Francisco, U.S.ASIGLEAvailable at INIST (FR), Document Supply Service, under shelf-number : RM 1221 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc