M. Witkowska

Influence of Cold Plastic Deformation on the Development of the Texture in High-Manganese Austenitic Steel

The research was carried out on 26Mn-3Si-3Al steel having a low value of SFE. After casting, steel was forged and hot-rolled at the temperatures within the range of from 1200°C to 900. Next, the steel was cold rolled until the deformation of 66% was obtained. Upon the basis of X-ray examination and the observations of microstructures, it was found out that during cold rolling mechanical twinning and the martensitic transformation of austenite in hcp-ε martensite occurred. The crystallographic texture of the γ phase (austenite) and ε phase (martensite) was also examined.

Microstructure and Deformation Behavior of Cold-Rolled Super-Duplex Stainless Steel

The present examination is a part of project concerning a deformation behavior of duplex type ferritic-austenitic stainless steels. The investigations included the analysis of ferrite and austenite microstructures formed in cold-rolled sheet of super-duplex stainless steel, major deformation mechanisms operating in both constituent phases and changes in morphology of two-phase structure after the thermo-mechanical treatment and subsequent cold-rolling. Duplex type stainless steels develop the band-like ferrite-austenite morphology in the course of hot- and cold-rolling. This specific two-phase structure creates different conditions for plastic deformation in comparison to single phase steels. The interaction of both phases upon deformation exerts fairly significant influence on structure and texture formation in both constituent phases and in consequence affects the material properties and its behavior upon further processing.

Textures of the Hot-Forged Ti6Al4V Alloy

This paper presents the results of the texture investigation in the hexagonal phase and the body-centered cubic  phase of the Ti6Al4V alloy hot-deformed by forging. Forging was performed at two different temperatures on the occurrence of the single  and in the two-phase  +  state. It was found that after deformation both  and  phases are textured and their textures strongly depends on deformation temperature.

Sigma Phase Precipitations in Duplex Steel SAF 2205

The present work concerns the precipitation process of the sigma phase in the ferritic-austenitic stainless steel of duplex type SAF 2205. After the preliminary thermo-mechanical treatment, the steel was subjected to cold rolling up to 85% of reduction and subsequent annealing in the temperature range 650÷950°C for various times. Significant structural changes were observed in the course of annealing treatment affecting the formation of the ferrite and austenite texture. The development of annealing textures resulted from recovery and recrystallization processes in both component phases and the precipitation of the sigma phase. X-ray investigations included the phase analysis, measurements of pole figures for case of each phase, austenite and ferrite. Microstructure of analysis was conducted by means of optical microscopy. The microstructure and texture of duplex type steel after annealing result from the precipitation process of sigma phase, depend on the temperatures and time of annealing.

Rolling texture differences in duplex steels with strong and random initial orientations

The present examination concerns a comparison of rolling texture development in two stainless steels of duplex type with different intensities of ferrite and austenite initial textures after a preliminary treatment, namely; clearly defined strong textures of both phases in one steel and nearly random textures in the case of the second one. Essentially the constituent phases in both duplex steels tend to develop the rolling textures comparable with those in single phase steels. However, the final textures display certain differences in comparison to the typical ferrite and austenite rolling textures. In both duplex steels the formation and character of the final deformation textures is strongly influenced by the band-like morphology of the ferrite-austenite structure and the process of texture formation proceeds in different way depending on the initial orientation distribution.

The Effect of Initial Orientation and Rolling Schedule on Texture Development in Duplex Steel

A development of deformation textures was examined in ferritic-austenitic duplex type steel subjected to cold-rolling within the range up to 90% of reduction by applying different rolling schedules. The investigations included X-ray phase analysis, texture measurements and microstructure observations by means of light microscopy. The experimental results indicate at the occurrence of strong initial textures in both component phases after preliminary thermo-mechanical treatment. Formation of the ferrite-austenite banded structure in the course of rolling along with the stability of major texture components, related by Bain orientation relationship, exert considerable effect on the development of the ferrite and austenite rolling textures.