Coercive Force, Texture, and Fracture in a Low_Carbon Steel Tube

The coercive force and crystallographic texture in a tube made from ferrite low-carbon steel are studied after fatigue and tensile tests during fracture after cyclic loading by hydraulic pressure. The texture was studied using synchrotron radiation (transmission geometry) by constructing three-dimensional distribution function of orientations. The typical texture of rolling of the ferrite steel is maximal in the median cross section of the tube wall, and the highest texture intensity is due to deformation preceding fracture. The coercive force is found to increase in portions neighboring to the fracture zone

Coercive force, texture, and fracture in a low carbon steel tube

The coercive force and crystallographic texture in a tube made from ferrite low-carbon steel are studied after fatigue and tensile tests during fracture after cyclic loading by hydraulic pressure. The texture was studied using synchrotron radiation (transmission geometry) by constructing three-dimensional distribution function of orientations. The typical texture of rolling of the ferrite steel is maximal in the median cross section of the tube wall, and the highest texture intensity is due to deformation preceding fracture. The coercive force is found to increase in portions neighboring to the fracture zone

Effect of chemical composition and texture on coercive force of hot-rolled TRIP steels

Due to the variation of the Mn content in trip steels magnetic behaviour correlates on one hand with quantitative texture and on the other hand with strain induced martensitic phase transition. Phase transition as well as crystallographic texture was investigated at 6 samples with three different Mn-contents and two different rolling degrees using a beam size of 500 X 500µm. To overcome the grain statistics problem for phase analysis rectangular samples were rotated 20° in omega to increase the gauge volume. Data collection was carried out during complete sample rotation. The trip steel with 0%Mn consists mainly of austenite with 94.5% weight% and small amount of ferrite or cubic martensite. With 2%Mn the major phase is still austenite with 85%. Strain induced martensitic phase transition starts to form the tetragonal martensitestructure I4/mmm with c/a ratio close to 1 (a= 2.87602Å; c=2.87901Å). In the case of the highest Mn content the tetragonality is much stronger (a= 2.87190Å; c=2.90521Å) and the martensite content increases to 78.2 %. The high brilliance of the synchrotron beams allows us to see the early stage of the tetragonal distortion, which starts at 2%Mn. It has to be noticed that the rolling degree has minor influence on the phase development than the Mn content. Even after 70% hot rolling a very weak texture with a texture sharpness of only Pmax=1.8mrd was obtained. The symmetry equivalent information related to the intensities in the pole figure center is not clear to detect, which makes the description of the pole figure risky. It is open whether it is a fiber texture or a combination of a fiber texture with a cube component (100) or a double fiber

Obtaining hexagon-shaped billets of copper with gradient structure by twist extrusion

Processing by twist extrusion was used to produce copper billets with a hexagonal cross-section. A special feature of the billets is their gradient microstructure owing to a specific strain pattern: an undeformed core and a deformed outer sheath. The initial sample with a 40mm diameter was processed at room temperature by four twist extrusion passes through a twist die having a hexagonal cross-section and a small twist-line slope angle β=40° with a back-pressure of 100 MPa. The results showed that the processed sample had an undeformed core 20mm in diameter and a deformed outer sheath with a gradient microstructure in which the average grain size decreased gradually from 50 μm to 0.5 μm towards the periphery along a radius direction. The microstructure gradient represented the various stages of the grain refinement process corresponding to increasing shear strain. The texture revealed two different shear deformation modes whose shear planes were perpendicular and parallel to the extrusion axis. The measured Vickers hardness showed good agreement with the microstructure. In the deformation zone, the classical Hall-Petch relation between the hardness and the grain size of the various characteristic areas formed by twist extrusion was found

Coercive force, texture, and fracture in a low carbon steel tube

The coercive force and crystallographic texture in a tube made from ferrite low-carbon steel are studied after fatigue and tensile tests during fracture after cyclic loading by hydraulic pressure. The texture was studied using synchrotron radiation (transmission geometry) by constructing three-dimensional distribution function of orientations. The typical texture of rolling of the ferrite steel is maximal in the median cross section of the tube wall, and the highest texture intensity is due to deformation preceding fracture. The coercive force is found to increase in portions neighboring to the fracture zone