Effects of asymmetric rolling process on ridging resistance of ultra-purified 17%Cr ferritic stainless steel

In ferritic stainless steels, a significant non-uniform recrystallization orientation and a substantial texture gradient usually occur, which can degrade the ridging resistance of the final sheets. To improve the homogeneity of the recrystallization orientation and reduce the texture gradient in ultra-purified 17%Cr ferritic stainless steel, in this work, we performed conventional and asymmetric rolling processes and conducted macro and micro-texture analyses to investigate texture evolution under different cold-rolling conditions. In the conventional rolling specimens, we observed that the deformation was not uniform in the thickness direction, whereas there was homogeneous shear deformation in the asymmetric rolling specimens as well as the formation of uniform recrystallized grains and random orientation grains in the final annealing sheets. As such, the ridging resistance of the final sheets was significantly improved by employing the asymmetric rolling process. This result indicates with certainty that the texture gradient and orientation inhomogeneity can be attributed to non-uniform deformation, whereas the uniform orientation gradient in the thickness direction is explained by the increased number of shear bands obtained in the asymmetric rolling process.

Characterization of the Flexural Behavior of Bamboo Beams

Bamboo is a renewable and environmentally friendly material often used for construction.This study investigates the flexural behavior of bamboo beams through theoretical and finite element(FE)analyses.Considering the material’s nonlinearity,a method of calculating load-deflection curves is proposed and validated via FE analysis.The interfacial slippage dominated by the shear stiffness of the interface between two bamboo poles significantly influences the flexural behavior of double-pole bamboo beams.Thus,the load-deflection curves for different shear stiffnesses can be obtained via theoretical and FE analyses.Subsequently,a novel configuration using diagonal steel bands to avoid slippage is presented.An inclination angle of 45°is suggested to adequately develop the stiffness and bearing capacity of the steel band.

Temperature dependence of Lüders strain and its correlation with martensitic transformation in a medium Mn transformation-induced plasticity steel

The Luders deformation behavior in a medium Mn transformation induced plasticity （TRIP） steel is investigated at different temperatures ranging from 25 to 300 ℃. It demonstrates that the Ltiders band appears at all testing temperatures but with varied Luders strains which do not change monoton ically with temperature. The martensitic transformation is simultaneously observed within the Ltiders band in varying degrees depending on the testing temperature. It is well verified that the martensitic transformation is not responsible for the formation of Luders band, and a reasonable explanation is given for the non-monotonic variation of Luders strain with increasing temperature.