Advanced Materials Research Vols. 652-654

Abstract: By referring to the heavy duty radial-axial ring rolling mill in production, a radial-axial ring rolling experimental equipment was designed and developed. Based on the principle of similarity, the mathematical relationship and calculation method between experimental rolling forces and actual ones in the process of radial-axial ring rolling were established. This experimental equipment has many advantages, such as compact structures, full functions, small deformation and more safety and reliability, which can be used in experimental study and calculation of ring rolling forces.

Abstract: This paper focuses on the extrusion process of powder/solid clad rods with the desired hole ratio in the center to reduce the weight. The finite-element model about a lot of deformation body extrusion was successfully demonstrated. Raw steel powder and steel tube were consisted as powder/solid rods. While the obvious plastic deformation proceeding in deformation region, the hole ratio clearly lessened, then a little rose apart from the deformation region. The deformation parameters were determined for the purpose to lesson the weight of the rod to about 15% hole ratio in powder deformation region. The extrusion experiment and the tensile property test proved that the integrative property improved while the weight was reduced. The clad rod can be utilized in the solid suck rods.

Abstract: The program 7A04 aluminum alloy loading-wheels spinning process is described briefly. It formulates the process parameters of aluminum alloy loading-wheels spinning. It uses the aluminum alloy sheet heat spinning process. It analyzes conventional spinning preformed and spinning flanging forming technology regulation. It studies the lubricating technology in the spinning process. The cracking problem is analyzed and solved in the spinning process. The mechanical performance test and the internal organization of the inspection are detected. The finished product meets the requirements. The small batch loading-wheels are produced, which lay the foundation for large quantities loading-wheel spinning production for future.

Abstract: In order to reduce the elastic recovery of a sheet material and eliminate a great number of solid dies used in the forming process of various shapes, a flexible stretch forming process (FSFP) is considered in this study. Especially, the relationship among design variables, such as the punch size, objective radius of curvature, and elastic pad thickness is quantitatively evaluated to find out their respective influences on the shape errors of a formed sheet plate using the statistical method based on the FE simulation result planned by the three-way factorial design. The shape errors are divided into two types based on the material behavior according to the widthwise- and tensile- directions. The correlations of the shape errors and the design variables are estimated through the Pearson correlation analyses. The punch size has a strong positive linear correlation with the widthwise- and tensile- shape errors, and the correlation between the objective curvature radius and tensile-direction shape error is weak and negative. Although the effect of the elastic pad thickness is less than those of the other variables, it prevents effectively surface defects. Subsequently, the mathematical model is assumed to clarify their relationship. Two regression equations are estimated in terms of the design variables regarding the widthwise- and tensile- shape errors. The shape errors could be inferred by the assumed model in the particular combination of the design variables; then, the acceptable punch size and elastic pad thickness can be determined according to the objective curvature radius.

Abstract: The slab design, which has direct effect on the yield rate of steel and the productivity of mill in the production of medium plate, is an important neck of the medium plate production. Therefore, for the slab design of medium plate production, all of the factors which will influence yield and production efficiency should be taken into account, such as how to determine the rolling system, the broadening rate, the compression rate; the limited dimension conditions of machine; the sheared residuce and the burning loss. And then, it combines the indents and different specification of on-site finished product to design the slab of medium plate.

Abstract: The paper brings the results of roughness analysis of formed part produced by CNC multi-pass conventional metal spinning. The influence of the spindle speed, workpiece geometry and planar anisotropy of the blank on the formed part roughness was studied. For experiment design, an orthogonal array L27(313) was used and ANOVA (Analysis of Variance) was carried out. Based on the results it is determined that the higher spindle speed leads to rough surface finish. The surface roughness measured in different areas of experimental samples (corner R10, conical area, cylindrical area) indicates that the worst surface finish is in the conical area. Roughness in different directions refer to the sheet rolling direction shows minimal differences.

Abstract: In the process of line heating, a pulsed electromagnetic force is added to steel plates as an approximately consecutive constrained force of certain frequency. It improves the condition of steel plates heated at high temperatures and the efficiency of steel deformation and be conducive to the control of process and the improvement for the accuracy of deformation. According to the actual needs of electromagnetic force assisted line heating process, the design ideas of circuit for the electromagnetic force assisted line heating device (EFALHD) and functions of the branch circuits are introduced. The distribution of the electromagnetic force and parameters’ influence rules are analyzed by building magnetic field and circuit coupling model in ANSYS. By adding thermal analysis on the electromagnetic field analysis, a new method of line heating finite element analysis is established to support the parameter determinations of EFALHD.

Abstract: In order to obtain the bulk ultra-fine grain materials with excellent performance under the conditions of severe plastic deformation, the law curves of squeeze pressure, stress and strain of the extrusion process on large-sized pure aluminum rods had been gotten by the finite element simulation of 6-pass ECAP. With the increasing of extrusion passes, the maximum extrusion load increases significantly and the distribution uniformity on the values of equivalent stress and strain improves. So the multi-pass equal channel angular pressing can achieve good effect of grain refinement and improves the distribution uniformity of grain-size.

Abstract: To improve the product properties of H-beams, it is essential to understand the effects of hot rolling parameters on the microstructure evolution of the beams. For this purpose, a thermo mechanical model was built with the finite element Package ABAQUS. By re-meshing the model, multipass large-deformation hot rolling process was simulated under the boundary conditions predefined in accordance with the practical production. Based on the hot rolling simulation, an impact analysis of strain rate, initial rough rolling temperature, and time interval between passes on the microstructure evolution of H-beam austenite was conducted. The analytical results are meaningful for optimizing hot rolling parameters and improving H-beam properties.

Abstract: Optimization and design for shape and size of pre-forging with numerical simulation have some advantages compared with the conventional methods. The optimization object is the pre-forgings of an aircraft wheel hub. A commercially available software DEFORM 3D is used for the finite element method (FEM) simulation of the forging process of the aircraft wheel hub. The pre-forgings with three different shapes and sizes were used for numerical simulation. The effects of shape and size of the pre-forging on mould filling, forging load, effective strain and effective stress were analyzed. Finally, the suitable shape and size of the pre-forging were obtained based on the numerical simulation results.