共查询到20条相似文献,搜索用时 187 毫秒
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WANG Jintao ZHANG Suoquan SUN Yezhong HE Xiaoming JIAO Sihai 《Baosteel Technical Research》2012,6(4):51-54
Alloying elements,such as silicon and manganese,have a major impact on the phase transformation point of steel.Specifically,manganese is an element for the expansion and stability of the austenite region,while silicon can expand and stabilize the ferrite region.Phase transformation occurs during the hot rolling process for the steel with certain silicon content,which leads to great changes of the deformation resistance,thereby affecting the rolling stability.Consequently,a better understanding of phase transformation in the rolling process will contribute to the enhancement of product quality.In this paper,the on-line rolling data were processed by means of the inverse calculation method.In this method,the steel deformation resistance with various silicon and manganese contents was obtained and analyzed to determine the deformation behavior of the steel,which can help improve the on-line control model and enhance the steel quality. 相似文献
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Considering the characteristics of large cylindrical shell rolling, such as double driving rolls, asymmetrical rolling and huge workpiece, a slab method was developed to establish the rolling force model. In this model, the non- uniform normal and shear stresses and the upper and lower surface temperatures of the workpiece were taken into ac- count. Moreover, the flow stress model, considering the dynamic recovery and dynamic recrystallization behaviors of the material, was established. The rolling pressure distribution, the rolling force, the rolling torque and the neutral points could be calculated quickly and easily by the roiling force model. The predicted results were shown to be in good agreement with the measured values, which indicated that the model can satisfy the requirement of industrial application. 相似文献
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ZHAOQi-lin LIUXiang-hua WANGGuo-dong XUJun ANHua-wei 《钢铁研究学报(英文版)》2005,12(4):35-39
A neural network friction model with very good prediction accuracy was developed on the basis of industrial data. Simulative calculation indicated that the accuracy of rolling force and motor power calculation can be improved using the calculated friction coefficient. It was found that reduction ratio and deformation resistance of strip has more effects than other parameters, and the effects of most parameters are affected by rolling speed. 相似文献
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In order to simulate and analyze hot strip crown and flatness accurately and efficiently, the 3-D (three-dimensional) coupled model involved in RPFEM (rigid-plastic finite element method) is improved based on the analytical model of forecasting rolling force distribution. In the analytical model, variational method is employed to solve the lateral flow of metal and influential function method is employed to calculate roll deflection, the lateral distribution of rolling force can be obtained rapidly by iterative strategy. Then the 3-D coupled model uses the result as initial distribution of rolling force to calculate roll deflection and makes the initial on-load roll gap profile close to the final value, so as to reduce iterations and increase efficiency. Compared with previous algorithms, the improved model can reduce the iterations by about 50% and shorten the computing time by about 60% on the basis of the calculation accuracy. 相似文献
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3D thermo-meehanical coupled simulation of whole rolling process for 60 kg/m heavy rail was accomplished by FEM method. The finite element model, physical parameters of U75V and parameter setting of simulation were introduced in detail. The whole rolling process of 60 kg/m heavy rail was divided into 27 time cells to simulate respectively, and the model rebuilding and temperature inheritance method in intermediate pass were proceeded. Then, based on simulation results, the workpiece deformation result, metal flow, stress and strain of 60 kg/m heavy rail for typical passes were obtained. The temperature variation curves of whole rolling process for section key points of 60 kg/m heavy rail were plotted, and the temperature falling law of whole rolling process for 60 kg/m heavy rail was studied. In addition, temperature distribution of 60 kg/m heavy rail after whole rolling process was analyzed, and the results showed that temperature was highest at center of rail head and lowest at fringe of rail base. Moreover, the simulation results and measured results of rolling force for 60 kg/m heavy rail were compared, and the regularity was in good agreement. 相似文献
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An integrated mathematical model is proposed to predict the velocity field and strain distribution during multi-pass plate hot rolling. This model is a part of the mixed analytical-numerical method (ANM) aiming at prediction of deformation variables, temperature and microstructure evolution for plate hot rolling. First a velocity field with undetermined coefficients is developed according to the principle of volume constancy and characteristics of metal flow during rolling, and then it is solved by minimizing the total energy consumption rate. Meanwhile a thermal model coupling with the plastic deformation is exploited through series function solution to determine temperature distribution and calculate the flow stress. After that, strain rate field is calculated through geometric equations and strain field is derived by means of difference method. This model is employed in simulation of an industrial seven-pass plate hot rolling process. The velocity field result and strain field result are in good agreement with that from FEM simulation. Furthermore, the rolling force and temperature agree well with the measured ones. The comparisons verify the validity of the presented method. The calculation of temperature, strain and strain rate are helpful in predicting microstructure. Above all, the greatest advantage of the presented method is the high efficiency, it only takes 12 s to simulate a seven-pass schedule, so it is more efficient than other numerical methods such as FEM. 相似文献
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The shape of strip is calculated by iterative method which combines strip plastic deformation model with rolls elastic deformation model through their calculation results, which can be called results coupling method. Because the shape and rolling force distribution are very sensitive to strip thickness transverse distribution′s variation, the iterative course is rather unstable and sometimes convergence cannot be achieved. In addition, the calculating speed of results coupling method is low, which restricts its usable range. To solve the problem, a new model coupling method is developed, which takes the force distribution between rolls, rolling force distribution and strip′s exit transverse displacement distribution as basic unknowns, and integrates strip plastic deformation model and rolls elastic deformation model as a unified linear equations through their internal relation, so the iterative calculation between the strip plastic deformation model and rolls elastic deformation model can be avoided. To prove the effectiveness of the model coupling method, two examples are calculated by results coupling method and model coupling method respectively. The results of front tension stress, back tension stress, strip′s exit gauge, the force between rolls and rolling force distribution calculated by model coupling method coincide very well with results coupling method. However the calculation course of model coupling method is more steady than results coupling method, and its calculating speed is about ten times as much as the maximal speed of results coupling method, which validates its practicability and reliability. 相似文献
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The error of gaugemeter equation decreases the gap setting precision. The precision of gaugemeter equation is strongly influenced by plate width, work roll radius, backup roll radius, work roll crown, backup roll crown and rolling force. And these influences are hard to measure. All these factors are converted to roll deflection deformation and roll flattening deformation for calculation. In order to calculate the deformation, the theory of influence function method was adopted. By using simulation program, the influence of these factors on deformation was obtained. Then a simple model can be built. With this model, it is convenient to analyze the influence of different factors on gaugemeter equation. 相似文献
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Mróz Sebastian 《钢铁研究学报(英文版)》2012,19(8):17-24
Change in the temperature of band over its length, associated with the stock being non-uniformly heated in the furnace, influences the variations in the magnitudes of energy-force parameters. Using the FEM (Finite Element Model) programs for the computation of the values of the energy-force parameters can take into account the distribution of temperature over the band length. The mathematical model of the computer program Forge2008 was used to theoretically examine the energy-force parameters and plastic metal flow in the roughing stands of the continuous rolling mill. The results of experimental investigation of influence of the non-uniform temperature distribution were presented on the metallic charge length on the energy and force parameters and dimensions of the band during round bars rolling. Thermovision monitoring energy and force parameters monitoring were carried out in continuous rolling mill D350 in one of the Polish industrial plants. On the basis of obtained results, it could be stated that non-uniform distribution of temperatures along the charge length causes local increase of energy and force parameters values and also such distribution affects the local increase of the width of rolled band. The rolling process of charge with non-uniform distribution of temperature could lead to exceeding required dimensional tolerances of the final products. 相似文献
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The plane strain asymmetrical rolling was analyzed using slab method. The contact arc was replaced by parabola, and the constant surface friction status was adopted during the analysis. The deformation area was divided into three zones according to the direction of the friction. Then, the three zones were studied, respectively. A rolling force model and a rolling torque model were developed based on the analysis, and they were used to analyze the influence of asymmetrical rolling factors on deformation area and unit pressure if they had good precision which was determined by comparing the calculated results with the measured ones. 相似文献
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In cold strip rolling control system, rolling force and forward slip are the prerequisites for the model setting calculation, and the deformation resistance and friction coefficient are the main parameters that affect their predictions. A new method based on objective function is first proposed in this paper to improve the calculation accuracy of rolling force and forward slip, and the deformation resistance and friction coefficient are taken as optimisation variables. Using the multi-population co-evolutionary algorithm to solve the objective function, the required rolling force and forward slip are obtained. The pre-set values of rolling force and roller line speed are compared with the actual measured ones in a 1450?mm five-stand tandem cold mill and other researcher’s method. Results show that the calculated values are in fair agreements with the on-line measured ones, and the thickness and flatness accuracy of the final product are improved. 相似文献
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热轧相变过程变形抗力模型研究与开发 总被引:1,自引:0,他引:1
对精轧阶段存在相变的热轧钢种,因变形抗力随轧制温度的变化规律与常规的奥氏体轧制钢种显著不同,使得传统变形抗力模型的预报误差较大,严重影响这类钢种的轧制稳定性。为此,研发了一种热轧相变过程变形抗力模型,通过在原变形抗力模型基础上添加一个新的相变趋势项,该修正项为轧制温度的二次多项式函数,并根据钢种分类来精细优化适应不同钢种轧制的多项式待定参数。该模型目前已成功应用于涟钢CSP热连轧生产线变形抗力在线计算,实际生产应用表明,新模型上线后,变形抗力与轧制力的预报精度显著提高,轧制力模型预报误差12%以内的比例从83.3%提高到96.7%,满足了热连轧精轧相变带钢的稳定生产要求。 相似文献
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为改善轧机控制系统中变形抗力的预报精度,提高产品质量,在分析原单机架轧机控制系统数学模型的基础上,选定温度影响项的系数作为修正系数,并将原长期自学习的算法改为渐消记忆的自适应算法。实现了以实测轧制力数据动态校正变形抗力,并运用VC60++编程实现。实际应用表明,给出的快速自学习策略优于原来的变形抗力工程计算方法,有效减少了产品的厚度误差,提高了板材的成材率和经济效益。 相似文献
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对宽厚不锈钢复合板层间真空热轧制变形过程进行受力分析,将热轧变形区分成I、II两个区间,运用主应力法建立各个区间的力平衡方程,根据边界条件和屈服准则求出各变形区的长度和各变形区所受压力,建立轧制力计算数学模型,在此基础上分析轧制工艺参数对宽厚不锈钢复合板轧制区间内不同应力分布的影响规律。将实际参数代入轧制模型计算公式,应用Matlab编程求得理论计算值,并与实测值进行比较。研究结果表明:轧制力模型可用于预测轧制力的大小,满足工程要求,轧制复合过程研究有助于优化成形工艺、预测产品性能,为今后此类材料的研究开发提供了参考依据。 相似文献
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采用厚度族划分及指数平滑处理的方法,对根据实际生产数据回归出的轧件变形抗力参数进行处理,从而实现了轧制力短期自适应。并以轧制力短期自适应为基础,建立了轧制力长期自适应模型。将上述模型实际应用于南钢3 500 mm精轧机过程控制系统中,获得了良好的效果。 相似文献
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为了提高精轧机轧制负荷的预测精度 ,提出一种在轧制负荷模型的结构中考虑相变和累计应变对轧制坯料变形抗力的影响和厚度方向的温度分布的新方法。采用本文所述的方法 ,预测精度优于旧模型。预测结果的相对误差限制在± 5 %以内。 相似文献