Papers by Keyword: Rolling Process

Abstract: In Thailand, the sheet metal products that were produced by rolling process have high demand and the consumption trend to grow in the future. Many new products, which made from rolling steel sheet, had been developed with various design. Thus the manufacturers have to improve the productivity through the investigation and analysis of different process parameters, which affect to the quality during the production. In this paper, finite volume method FVM had been applied to analyze different effects of processes parameters such as temperature, roller speed, friction, size and capacity of rolling machine. The commercial software MSC.SuperForge was used in the modeling and simulation of metal deformation under the flat rolling process. Considering the predicted results compared with the experimental data, the different in dimension error data were within an acceptable range of quality specification. The error in width of finished steel sheet was 1.17%, the length was error of 1.50%, and the thickness was error of 2.32%. By using this technique, different factors affected during rolling process can be investigated and controlled such as the metal flow, the distribution of stress and strain, and the deformation zone.

Abstract: Tailored blanks with different blank thicknesses are semi-finished parts that can be used to produce stamping parts having a real tailor-made solution. This study investigates a manufacturing process that can produce a tailored rolled blanks(TRB) having variable thickness variations both in longitudinal and width directions. The process was experimentally and numerically investigated using three types of the conventional blank and blanks having circular and square holes. To characterize the process, the deformation behaviors of blanks were intensively analyzed. In order to understand the effect of the blank shape on the manufacturing TRB, the strain behaviors was compared by numerical simulation. The results show that the hollow blanks have good formability in the manufacturing of TRB having variable thickness variations both in longitudinal and width directions compared with the conventional blank.

Abstract: Numerical estimation of rolling load and torque often showed large discrepancies when compared with experimental values. This was attributed to difficulty in estimating the mean rolling temperature from the available data. This work is thus directed at obtaining a good estimate for the mean rolling temperature which can effectively be used for load and torque estimates. Hot flat rolling stimulation by use of the Bland and Ford’s cold rolling (HRBF) theory confirmed the reverse sandwich effect in selected carbon steels at low strain rates. In this work, the effect of pass reduction on rolling temperature distribution, yield stress and rolling load were studied for AISI Type 316 stainless steel (HSCSS316). For this new simulation, at low and high strain rates, results showed that the ratio of experimental to calculated rolling load and torque were higher at lower reduction than at higher reduction. These results confirmed excess load and torque in the hot rolling of HSCSS316 low reductions. The results obtained from Hot Rolling Bland and Ford’s Theory based on Root Mean Square rolling temperature were in good agreement with values obtained using Reverse Sandwich Model and the Reverse Sandwich- Hot Rolling Bland and Ford’s Program under the same rolling conditions.

Abstract: Existing methods of quality assessment of flat products are not sufficiently effective: they can be used for technological process management with certain limitations. Our research suggests an improved approach to the calculations of priority number of risks. The new suggested approach will allow risk assessment of dependent undesired events.

Abstract: The Institute of Metal Forming and Safety Engineering has developed technology for manufacturing grade X80 pipeline plates according to European standard EN 10208-2. Experimental chemical compositions ensuring a high level of yield strength have been developed. The article describes a method for selecting chemical composition [1]. The advancement of rolling technology takes much time and many calculations. Thus, using numerical simulations provides a possibility of a theoretical analysis of the plates made from new materials [4], [5]. Preliminary studies [1] have disclosed a large volume of deformations during the rolling process, which causes the distortion of rolls and generates heavy loads. For the theoretical analysis of rolling plates, Forge 2008® was used. The paper presents the obtained results of energy analysis and strength parameters displayed in Figure 1. The article considers a total amount of pressure on metal rollers and changes in the rolling moment.

Abstract: Self-lubricating bearings are the basic components of the aviation industry, and the precision forming process of bearings is one of the kernel technologies, which is urgent to be self-developed. A method called unconstrained surface directional rolling process was put forward, and then the flow chart of process optimization was designed. Based on the numerical analysis model of rolling process, Latin hypercube sampling method was used for the design-space analysis. By using BPF+NSGA-II and Kriging+PSO algorithms, the rolling process was simulated and optimized, and then the results were verified by experiments. Study shows that by the use of the new proposed process and the optimization methods, the products can get a higher quality; results of optimization and experiments are valid and consistent, comparing with BPF+NSGA-II algorithm, results of Kriging+PSO algorithm are slightly better.

Abstract: The effect of isothermal-rolling process on the morphology, size and distribution of type II MnS was studied based on Gleeble-1500 simulator. The experimental results show that the relative plasticity of type II MnS increases with deformation temperature decreasing, but, it increases first and then decreases with deformation amount increasing; Heavy compression deformation is beneficial to improve the distribution of type II MnS; The changing trends of the size of type II MnS for varying deformation amount are basically same with deformation temperature changing, i.e. the average length of sulfides is shorter, and the average width is wider at high temperature rolling process; Under the same deformation temperature, the average size of type II MnS shows cyclical change with deformation amount increasing.

Abstract: Hot strip cooling temperature and its cooling rate is get by strip cooling system and coiling temperature of hot rolled strip is an important parameter on its performance index. It presents laminar cooling system of the 700 mm hot strip mill and the mill rolling process is present, the laminar cooling system is analyzed on the rolling theory and techniques. The laminar cooling system and its problems are present. The improvement programs of laminar cooling system are present, The control system of laminar cooling system is present combining feed-forward main control and feed-backward self-learning control, and measuring instruments is reinstall and water valves is improved. It could be a reference for the similar mill units and new building rolling mills.

Abstract: In this work, the conventional rolling (CR) and warm rolling (WR) have been carried out with an ultra purified ferritic stainless steel. After different rolling processes and subsequent recrystallization annealing, different recrystallized microstructure characteristics had been obtained. It was observed that as compared to the conventional process, the warm rolling and subsequent recrystallization annealing could obviously refine the recrystallized microstructure of the hot band. The ductile-to-brittle transition for the ultra purified ferritic stainless steel can be closely related to the occurrence of deformation twinning. The refined microstructure can decrease the temperature at which twinning occurs and, consequently, the ductile-brittle transition temperature for the ultra purified ferritic stainless steel was lowered to be below -40°C, and its notch toughness was significantly improved when the fine grain route can be applied.

Abstract: The nearly stoichiometric Fe-Co alloy is well known as soft magnetic materials with high saturation magnetization and Curie temperature. However, the application is restricted by its brittleness and poor machinability. For this reason, we studied the rolling process of this alloy. Firstly, the effect of final thickness of hot rolling on the cold rolled samples showed that there was little difference for these cold rolled samples, and the thinner hot rolling samples were not so easy to crack during the cold rolling. Secondly, the soft magnetic properties were found to be better under the 1050 water quench when we studied the influence of different solution temperature on soft magnetic properties. Thirdly, with the increase of annealing time, grain size and soft magnetic properties of 1J22 alloy increased, whereas mechanical properties decreased.