Automated control of rolling modes on plate mills

Indicators of rolling quality and rolling process are presented, which determine the efficiency of plate mill operation. The purposes of the automated control of rolling which consist in achievement of an optimum ratio of the mentioned indicators, and division of control channels (when it’s possible) achiev-ing the best values of each indicator named above. Control of rolling modes (compression on passes, speeds, cooling) provides the main effect in indicators quality formation of hire and rolling process. The statement of the problem of automated rolling control is given. The choice of the optimized indicator in the problem of automatic rolling control is determined by its economic significance, the nature of the interrelation with the technological parameters and controls. One of the most economically significant for plate mills is the coefficient of metal consumption of the workpiece per ton of rolled product, or the yield, which depends on the accuracy of the implementation of the specified geometric dimensions of the rolling strip. The formulation of the problem of ensuring the minimum value of deviations in the thickness (width) of the strip from the specified value is given. The problem of optimization on one of three indicators of the rolling process is also formulated: the equivalent torque of the main drive, the electricity consumption for rolling and the time consumption of the rolling cycle, which are determined by the entire course of the rolling cycle, i.e. applied management strategy. The principles of solving the problem of automatic control of rolling modes are described. The rolling control strategies used in the ACS TP of plate mills are considered. Methods of constructing mathematical models for ACS TP of plate mills, as well as their adaptation, are described.

Effect of growing media on mat type seedling raised for mechanical rice transplanting

Mechanical transplanted seedling must meet the requirements of standard seedling block with uniform distribution of seedlings and inter-twisting roots for rolling. This study was conducted to identify the effect of growing media on mat type seedling raised for mechanical transplanting at Bangladesh Rice Research Institute (BRRI), Gazipur during the period of 2012–2014 covering two dry and cold seasons (Boro) and one wet season (Aman). Seedling were raised on plastic tray using sandy loam and clay loam soil mixed with decomposed cow-dung, mustard cake, rice straw organic fertilizer, rice bran, poultry litter and vermicompost at the rate of 0.0, 10, 20, 30 and 40%. Rolling quality of the seedling mat decreased and seedling height increased with the increased of mixing rate of organic fertilizer except rice bran and mustard cake. Averaged across three seasons, 10 to 30% cow-dung, rice straw organic fertilizer, vermicompost, 10% poultry litter and 20 to 30% rice bran with both types of soil was found suitable for seedling mat and seedling height. However, seedling varied among the organic fertilizers with both types of soil in the order of cow-dung > rice bran > vermicompost > poultry liter > rice straw organic fertilizer > mustard cake. Clay loam soil showed better performance on rolling quality over sandy loam soil.

The Uniform Elongation Experiment of Web and Flange of H-Beam

Web and flange of H-beam are deformed indifferent zone in the rolling process, so non-uniform deformation is easily generated. In order to ensure the uniform elongation of flange and web, usually , the elongation ratio of flange is 3~5% more than that of web. Web wave or crack often appears. Flange wave, crack even tension fracture often appears. Experiment are designed that the elongation ratio of flange and web are changed to ensure the uniform elongation of flange and web. Thus, the rolling quality of H-beam is improved. The recommended rolling rule is provided, which can provide the accordance for actual production.

The Mill Pacing Research Based on the Optimized Plate Model

In This paper, in the background of a plate milling system in China, various influences on mill pacing in plate rolling are taken into consideration, a plate model by using the objective optimization theory based on the field statistics are introduced. This model based on the differential evolution, that establishes the objective function of rolling quality-temperature waiting time-rolling time, and uses concurrent optimization for the plate rolling of various needs. The results could get a series of Pareto sets to content the different requirements of determining the contiguous slab’s out-stove time interval. Lastly, the test examples are simulated to check up, the Pareto sets are calculated, and the result shows the method is effectiveness.

Study on Tooth Profile Errors of Flexible Wheel Cold Rolling Machining

The harmonic gear cold rolling process is an effective method to solve mass production. However, tooth profile quality problems greatly hinder the development of the process. Based on engagement theory, the dynamic characteristics of the rolling process and flexible wheel rolling tooth profile errors caused by the changes of the number of contact points were analyzed and studied, and the process methods were put forward to eliminate or reduce tooth profile errors in this paper, which has an important significance in analysis of rolling tooth profile errors, modification shape of the rolling wheel, optimization of process parameters and improvement of gear rolling quality.

Research of the Roll Systems Flexural Coupling-Dynamic Modeling

Rolling process is a typical and complex nonlinear dynamic one which determined by the couple-interaction of different physical attribute movements. Different forms of dynamic response will be reacted by the external excitation on mill system, such as the fluctuation of the rolling force. The vertical vibration and the roller axial flexural deformation, among these dynamic responses, are the main factors which would affect the strip after rolling quality. In order to exactly describe the roll systems vertical vibration and the roller axial dynamic property, this article is focused on the mathematical modeling of the roll systems vertical vibration and the lateral flexural vibration. Take the situation, the roll systems vertical vibration and the lateral flexural vibration occur simultaneously, into account, the authors build the lateral coupling-dynamic model of the roll system. Using numerical simulation method, the authors analyze the interaction between the roll systems vertical vibration and lateral flexural vibration.

The Influence Rules of Stress about Technical Parameters on Synchronous Rolling Railway Axis with Multi-Wedge Cross-Wedge Rolling

Multi-wedge synchronous rolling by cross-wedge rolling is one of the most advanced methods that can form rolling railway axis. Its rolling quality mainly lies on inner transversal stress and shearing stress of rolling workpiece. In this paper, based on the rotated theory of multi-wedge rolling, through using Ansys/Ls-Dyna FEM software, multi-wedge synchronous rolling railway axis by cross-wedge rolling is simulated. It has been systemically researched that technical parameters effect transversal stress and shearing stress. In the meantime, the calculating model is verified by experiment. Through this study, It is obtained that the law of technical parameters effect on rolling railway axis by multi-wedge synchronous cross-wedge rolling. These research conclusions can provide scientific basis for rolling railway axis by multi-wedge synchronous cross-wedge rolling and rolling better quality.

Downstream Considerations of Fusion Clad Casting

Fusion casting has been commercially available for over 3 years. Although there are many interesting points to casting, there are several downstream considerations such as scalping, preheat and rolling. Quality rolled clad sheet needs to have a consistent clad thickness. Appropriately varying the geometry of the clad layer during the transient portions of casting results in consistent clad thickness from head to butt. Controlling the edge wipe during rolling off does the same from edge to edge. The severity of edge wipe off can be predicted from relative flow stresses at rolling temperatures and guides the choice of alloy combinations.