Papers by Keyword: Roll Pass Design

Abstract: A universal geometric model of the deformation zone during rolling of a "random shape" workpiece in a two-roll groove of a "random shape" is considered in this paper. The level of simplicity of the model should provide, on the one hand, a sufficiently detailed and accurate description of the deformation zone geometry and, on the other hand, ensure the possibility of implementing "fast" algorithms for calculating the necessary characteristics of the rolling process.

Abstract: The analysis of two roll pass design options of ten roughing stands atOJSC “MMK” 370 rolling mill has been performed. The usage of a new form of the roll grooves will allow achieving higher durability of the rolls. Lesser rolls consumption will allow saving up to 800K rubles annually. More uniform load distribution by the stands will reduce the possibility of main mill lines equipment breakdowns due to the jumps of rolling torque in the most loaded non-equiaxial stands. Better contact conditions and higher billet stability at the input into equiaxial grooves will reduce the amount of metal clogging. Moreover, a changed strain diagram – with higher roll pass design efficiency factor – will increase the roll out of foundry production defects.

Abstract: In this work, a rolling schedule has been developed, which allows the scrapped S60 railway rail to be used for further processing into semi-finished or finished products. The main purpose of the investigations was to develop the shape and dimensions the rolling grooves and to select the strains in various passes in the ploughshare rolling process. The main problem during roll pass design was the ploughshare shape which is asymmetric and has a varying thickness along the width. The developed roll pass design consist of five passes: one open shape pass, one edging pass and three closed shape passes. The first open shape pass is characterized by an unusual shape which tends to reduce the band asymmetricality in the horizontal axis in such a manner as to prevent the formation of lapping in the sharp corner areas resulting from cutting. Based on the numerical modelling it has been found that the developed roll pass design allows the production of a ploughshare of dimensions conforming to the dimensional assumptions. For the numerical modelling of the rolling process, the Forge2008® computer program was employed.

Abstract: The primary purpose of this study is to develop a genetic algorithm based computer-aided roll pass optimal design (CAROD) system to support the generalized roll pass design for rod rolling, where the final products are round bars with different sizes. The system was developed to minimize the number of roll passes, decrease the trails and errors in industry, as well as extend the work range of multi-pass rolling systems for rod rolling. Parametric equations were established for geometrical modeling and graphic plotting, which can realize to the parametric transformation for roll pass design and optimization. A methodology based on a hybrid model was proposed to choose passes with different profiles for the multi-pass rod rolling system. In addition, an improved genetic algorithm (IGA) was employed for the optimization of roll passes. A MATLAB program was designed to achieve all these objectives. To reduce the complexity and computational burden of the software, some reliable empirical formulas were applied in this system. Finally, the proposed approach has been applied in a rod rolling system; through simulation and comparison of results against analytical solutions, numerical analysis and experimental data presented by other researchers, it was found that this system is reliable, effective and easier to use.

Abstract: Hot steel rolling is amongst the most important industrial techniques because of huge amount of consumed resources, immense environmental impact, and the significance and enormous quantity of long products. Criteria for improving rolling operations include process efficiency, resource consumption, system reliability, product quality and ergo-ecological sustainability. There is an increasing availability of information within and beyond the domain of forming by rolling. With advances in computerised information processing, it becomes apparent that further progress is to be sought in intelligently combining the strategies and theories developed in differing disciplines. The key to optimising rolling systems is to be found in hybrid models. This approach calls for utilising cross-disciplinary knowledge, including a selection amongst methods such as stochastic, fuzzy and genetic modelling, process control and optimisation as well as supply chain and maintenance management. Evidence obtained by experiments using small-scale chemo-physical modelling encourages the use laboratory rolling for preliminary validations. Research strategy is conceptualised on the basis of a knowledge-based hybrid model. The sample space for this model is constituted by the rolling passes translated into the form of vectors. An example of a rolling pass translation into the vector form is presented.

Abstract: In this paper, we present an analytic approach for the prediction of roll force to be applicable to the billet rolling process which consists of a series of horizontal stands and vertical stands. The approach is based on the deformation shape and employs the assumption that the deformation homogeneously occurs in three directions. Strain and strain rate are calculated by the geometric relationships between those components and the prescribed deformation functions. By integrating the stress components along the rolling direction, roll force is finally obtained. The prediction accuracy of the proposed model is examined through comparison experimentally mesured roll force with computed ones.