Influence of stamping parameters on stamping characteristics of SAF2205 bidirectional stainless steel

SAF2205 bidirectional stainless steel is an excellent material for multiple corrugated diaphragms. It is necessary to study its stamping forming characteristics and provide a theoretical basis for stamping forming of multiple corrugated diaphragms. In this paper, the detailed V-bending process parameters are formulated. The effects of bending speed, relative fillet radius, temperature, and alignment time on spring-back behavior of SAF2205 bidirectional stainless steel are systematically studied to reveal the positive and negative spring-back mechanism. The range of process parameters suitable for stamping of SAF2205 bidirectional stainless steel was obtained. Article Highlights The detailed V-bending process parameters are formulated. The effect of SAF2205 parameters on the spring-back behavior was studied. The range of process parameters suitable for stamping of SAF2205 was obtained.

Study on Counter-Roller Spinning Technology of Large Diameter Aluminum Alloy Cylindrical Parts

Counter-roller spinning is an optimal process for forming large diameter cylindrical parts. In this paper, the finite element model of large diameter aluminum alloy cylindrical parts Counter-roller spinning is established, the regularities of distribution of stress and strain of each pass of the workpiece is obtained, as well as the influence of the roller feed ratio and fillet radius on the forming quality is obtained. The process parameters were optimized by grey correlation analysis. In this paper, for large diameter aluminum alloy cylindrical parts, the optimal spinning parameters are obtained as follows: the feed ratio is 1.0mm/r, the rotary roller fillet radius is 8mm. The results of numerical simulation are consistent with those of process test. The technological parameters can be used to guide the actual production of such large diameter cylindrical parts.

Using finite element analysis to discuss the study of drawing of servo stamping curve

This study employed different molding parameter combinations, the Taguchi method, ANOVA, and response surface methodology to perform experiments. Finite element analysis was executed to find the optimum molding parameters and increase the depth of drawing molding. The material is aluminum alloy 6016, and the servo press was adopted for the experiments. The factors influencing the drawing molding including punch fillet radius, die fillet radius, die clearance, molding curve, and mold temperature were determined. To find the optimum combination of parameters and to design 16 experimental combinations, the L16 orthogonal array of the Taguchi method was employed. According to the experimental results, the optimum parameters include punch fillet radius of 8.5 mm, die fillet radius of 8.5 mm, clearance of 1.5 t, curve 3, and the mold temperature of 20°C. Using the optimum parameter combination the molding depth could be increased greatly and the thickness ratio could be improved.

The Deep Drawing of a Flanged Square Hole in Thin Stainless Steel Sheet

To manufacture metal products of accurate size and shape by deep drawing requires the precise control of a number of variables. The problem of spring-back after the load has to be avoided, and the prevention of cracks in the product requires careful control of the punch load. In this study, where drawing experiments and simulations were carried out on thin sheets of SUS304 stainless steel, the influence of the scale effect on the thin sheets also needed consideration. This was accomplished by the use of an updated Lagrangian formulation and finite element analysis. Material behavior was simulated using a micro-elastoplastic material model, the performance of which was compared with that of models involving conventional materials. The Dynaform LS-DYNA solver was used for simulation analysis, and pre and postprocessing were carried out to obtain material deformation history as well as to determine thickness change, distribution and material stress, and prepare strain distribution maps. Scaling was necessary to account for the effect of the thickness of the sheet and the relationship between punch load and stroke, the distribution of thickness, stress and strain, and the maximum size (d) of the flanged hole and the maximum height of the flange. The simulation results were compared with experimental results to confirm the accuracy of the three-dimensional finite element analysis of the elastoplastic deformation. The results showed that the size of the fillet radius of the hole (Br) had an effect on the punch load, which increased with an increase in Br. However, the minimum thickness of the formed flange decreased with an increase in Br. The maximum principal stress/strain and height of the flange also increased with an increase in Br. The punch fillet radius (Rp) also had an impact on the process. The punch load decreased with the increase in Rp, while the minimum thickness increased slightly. The average values of the minimum thickness for three models were 0.148, 0.0775, and 0.0374 mm. The forming ratio also had an influence on the process. When the forming limit of the square hole flange was FLR = 0.84, cracking occurred in the corners of the flange, and wrinkles formed over the undrawn area of the sheet. These findings can serve as a valuable reference for the design of deep drawing processes.

An Improved Cutting Force Model for Ultrasonically Assisted Grinding of Hard and Brittle Materials

Cutting force is one of the most important factors in the ultrasonically assisted grinding (UAG) of hard and brittle materials. Many theoretical and experimental studies show that UAG can effectively reduce cutting forces. The existing models for UAG mostly assume an ideal grinding wheel with abrasives in both the end and lateral faces to accomplish material removal, whereas the important role of the transition fillet surface is ignored. In this study, a theoretical cutting force model is presented to predict cutting forces with the consideration of the diamond abrasives in the end face, the lateral face, and the transition fillet surface of the grinding tool. This study analyzed and calculated the vibration amplitudes and the cutting forces in both the normal and tangential directions. It discusses the influences of the input parameters (rotation speed, feed rate, amplitude, depth and radius of transition fillet) on cutting forces. The study demonstrates that the fillet radius is an important factor affecting the grinding force. With an increase in fillet radius from 0.2 to 1.2 mm, the grinding force increases by 139.6% in the axial direction and decreases by 70% in the feed direction. The error of the proposed cutting force model is 10.3%, and the experimental results verify the correctness of the force model.