Narrow Results

Numerical simulation and intelligent optimization technology were adopted for rolling and extrusion of zincked sheet. By response surface methodology (RSM), genetic algorithm (GA) and data processing technology, an efficient optimization of process parameters for rolling of zincked sheet was investigated. The influence trend of roller gap, rolling speed and friction factor effects on reduction rate and plate shortening rate were analyzed firstly. Then a predictive response surface model for comprehensive quality index of part was created using RSM. Simulated and predicted values were compared. Through genetic algorithm method, the optimal process parameters for the forming of rolling were solved. They were verified and the optimum process parameters of rolling were obtained. It is feasible and effective.

High-strength galvanized steel has the advantages of high strength, lightweight and high reliability. However, there are many defects in the forming process, especially the springback, which seriously affects the forming quality. To improve the forming quality of high-strength galvanized steel in rolling forming, a three-dimensional finite element analysis model of a hat-shaped section roll forming process was built by software ABAQUS. The hat-shaped section with a single-layer flange was simulated with three different base-level roll forming methods. The base-level roll forming method was used to simulate and experiment the hat-shaped section with double-layer flanges. This paper provided a method to precisely control the springback angle of high-strength galvanized steel and improved its forming quality.

High strength steel has been increasingly used in auto body design to achieve lightweight and safety. Recently WISCO made great efforts in research and development of HSS, including new grades development, new forming technology research and application. DP780 as a typical UHSS had been widely applied in car body parts after deep investigation in all kinds of properties. Springback analysis and welding test had been carried out to have better understanding in different grades of HSS. Roll forming, as an efficient forming technology, had been successfully applied in processing WISCO's hot rolled high strength steel product used for bus body. Many Optimizing methods were researched and utilized to provide high quality roll formed parts to customers. In hot forming area, WISCO had been working on boron steel development, tool design, whole process technology, tailed blank design, and post-treatment for part surface for long time. A lot of novel research results showed that hot forming will be more and more important in lightweight and safety for the future vehicles.

Square/rectangular steel tubes are widely used in various industry fields and their quality is related greatly to manufacturing technologies. In this study, a new roll forming technique to manufacture square/rectangular tubes from round pipes is modeled and studied with the finite element method. In the proposed forming process, the horizontal and vertical rolls are installed alternately at the forming stands along the longitudinal direction and the corresponding pass profiles are no longer closed as in conventional reshaping process. The interference between driving horizontal and vertical rolls can be prevented, and more rolls can be used as driving rolls to provide larger driving force. Furthermore, the forming rolls become reusable and can be commonly used in manufacturing the tubes with different sizes. The forming characteristics of the new reshaping process are analyzed and process is designed through comparison among different forming schemes.