Flow stress and barreling behavior of aluminum alloy during upset forging at elevated temperature

Upset forging test at elevated temperature of aluminum alloy were experimentally carried out at specified temperatures ranging from 30⁰C (room temperature) to 300⁰C and at different true strain levels under a constant strain rate of 1 X 10-3/s using powdered graphite mixed with machine oil as lubricant throughout the tests. Calculations were made to radius of curvature of barrel with the assumption that the curvature of the barrel followed the form of a circular arc. The radius of curvature of the barreled aluminum cylinders measured physically was found to confirm closely to the values calculated using the experimental data even at higher temperature. Generalized characteristic equations for each temperature have been developed by regression analysis. It was found that both the strength coefficient and strain hardening exponent decreases with increase in temperature. A common characteristic equation considering both strain and temperature was also found out. Further, different stresses like hoop stress, hydrostatic stress and effective stress have been found out for different temperature using the dimensions of the deformed specimens

Texture-tensile properties correlation of 304 austenitic stainless steel rolled with the change in rolling direction

Abstract Rolling, at elevated temperature, with a change in the rolling direction (RD) have been conducted on 304 austenitic stainless steel. Two different sequences of change in RD, after each pass, have been followed viz., change in RD by 90°; designated as cross rolling (CR) and change in RD by 180°; designated as reverse rolling (RR). Effect of this change in RD on texture and tensile properties has been studied through Electron backscattered diffraction (EBSD) and uniaxial tensile test, respectively. In addition, tensile tests have been performed to study the anisotropy in tensile properties. The result shows a significant effect on the texture component formation. RR develops strong Cu and S components whereas CR forms strong Brass component. However, both the rolling sequence produces moderate Goss orientation. The observed tensile properties are correlated with the texture developed by both the processes.</jats:p

Texture development in 304LN austenitic stainless steel during post-hot-axisymmetric compression

In the present work, 304LN austenitic stainless steel has been considered for the texture evolution study after the hot-deformation process. The axi-symmetric compression tests, with post-deformation isothermal holding at the same temperature, were performed at 900°C, 1000°C and 1100°C with a strain rate of 0.1 s−1. Texture evolution during the post-hot-deformation was studied through electron back scattered diffraction. Effect of temperature and holding time on texture evolution were studied. At low deformation temperature and lesser holding time 〈100〉 and 〈110〉 fibre textures were observed. At high deformation temperature and/or high holding time the texture becomes random. Texture intensity along α fibre, for all the temperatures, is chaotic whereas along β and τ fibres it is uniform at low temperature and becomes chaotic with the increase in deformation temperature. Goss component was found to be a major texture component with significant amount of ND and RD rotated cube components. </jats:p