Inspection of the adhesion strength of an electrical insulating coating with the surface of anisotropic steel

It has been shown that the thickness of a coating does not affect its adhesion strength with metal. As the metal thickness increases, for each 0.01 mm, the critical diameter of bending of a specimen at which the coating exfoliates increases by 1 mm. The presence of chromium in the electrical insulating coating causes its adhesion properties to decrease. The quality of the ground layer is a very important characteristic affecting the adhesion strength between the coating and metal.     

Evaluating the level of residual stresses in anisotropic electric steel

The level of residual stresses (RS) in anisotropic electric steel (AES) is its most important functional characteristic that is responsible for losses of electric power in magnetic circuits of transformers during their service life. Reasons are given for the emergence of RS in AES and the known estimation methods are provided, the main shortcoming of the latter being the lack of quantitative estimates of RS. A simple and practically feasible method is suggested for estimating RS based on measurement of the anisotropy of magnetic properties of AES.     

Inhomogeneity of magnetic properties of an anisotropic electrical steel and specific features of dislocation structures

Differences in the dislocation structures formed owing to the development of creep during high-temperature annealing and annealing for correcting coil curvature are shown to be one of the reasons for the inhomogeneity of magnetic properties of industrial anisotropic electrical steels. A relationship between the character of the dislocation structure, structure of magnetic domains, and magnetic losses is established. The dislocation cellular structure formed at grain boundaries exerts the greatest effect on the magnetic losses.Translated from Defektoskopiya, Vol. 40, No. 11, 2004, pp. 69–78.Original Russian Text Copyright © 2004 by Sokolov, Dragoshanskii, Matveeva, Tsyrlin, Mineev, Puzhevich.     

钢板卷取机卷塔形的原因分析及其对策

分析钢板在卷取过程中塔形的形成原因以及应采取的技术措施。     

基于谱残差视觉显著性的带钢表面缺陷检测

针对带钢表面缺陷检测实时性要求高,采集的图像易受光照环境影响且缺陷特征弱等因素影响,提出一种基于谱残差视觉注意模型的带钢表面缺陷在线检测算法。首先,提出改进同态滤波方法对图像预处理,去除光照不均匀的影响,改善后续的分割结果。然后,构建谱残差视觉注意模型,通过对数频谱曲线差分得到缺陷显著图像。最后,提出加权马氏距离方法对显著图像阈值化增强,并利用连通区域标记法,标记出原带钢图像的缺陷位置。对提出的算法进行了实验验证,结果显示:该算法检测速度快,单幅图像平均检测耗时仅37.6ms,满足带钢在线实时检测要求。在同一缺陷数据库与灰度投影法,多尺度Gabor边缘检测法和隐马尔可夫树模型法进行了性能对比,结果表明:本文算法对带钢常见8类缺陷类型,平均检测率达到了95.3%,且漏检率和误检率较低,有效性高于对比算法。     

Upper-bound modelization of an ironed three-layered polymer-coated steel strip

Global beverage can and food container consumption is very high, with billions of cans produced annually worldwide. There are several steps in can manufacturing, but ironing is the most crucial. In a previous work (Sellés et al., J Mater Process Technol 202:7–14, 2008), a series of ironing experiments were reported using a new material and an ironing simulator. This material was a three-layered polymer-coated steel, and it was seen that under some process conditions, it survived the ironing process with no damage in any of the three layers. The critical die angle was determined as well as specimen quality surface tests. In this paper, an associated theoretical ironing model is described, using the upper-bound theorem and considering the cases of successful ironing or shaving. It is possible to give insight into how to design a material that irons well. For example, the optimal layer thicknesses are also found.     

带钢生产线液压横剪机的设计

介绍了液压横剪机的外形结构及液压控制系统工作原理，并对横剪机的剪切力、压紧力、剪刀行程、液压缸选型等参数的设计、计算作了详细分析，并通过设计实例的计算过程加以验证。     

Contactless technique for the measurement of electrical resistivity in anisotropic materials

Measurement of basal plane electrical resistivities in quasi-two-dimensional materials by conventional four-point bridge techniques is extremely difficult. In making measurements of room temperature basal plane resistivities in highly conducting highly anisotropic synthetic metals we have developed an rf inductive technique which is both simple to use and provides accurate results. At the frequency we employ (100 kHz) the method is appropriate for resistivities in the range 10 (-3)-10(-7)Omega cm. Samples are thin square plates 5 mm on a side. The system is calibrated by fitting data from a series of samples of known resistivity to semi-empirical formulae. The theoretical motivation leading to these expressions is discussed and extensive calibration data are presented. The advantages of rf techniques in general have already been discussed. Two advantages commend the particular technique we describe here. First, it is simple in design and easily constructed. Second, with careful calibration, highly accurate resistivity measurements can be made in a very straightforward manner.     

Genetic based sensorless hybrid intelligent controller for strip loop formation control between inter-stands in hot steel rolling mills

Safe operating environment is essential for all complex industrial processes. The safety issues in steel rolling mill when the hot strip passes through consecutive mill stands have been considered in this paper. Formation of sag in strip is a common problem in the rolling process. The excessive sag can lead to scrap runs and damage to machinery. Conventional controllers for mill actuation system are based on a rolling model. The factors like rise in temperature, aging, wear and tear are not taken into account while designing a conventional controller. Therefore, the conventional controller cannot yield a requisite controlled output. In this paper, a new Genetic-neuro-fuzzy hybrid controller without tension sensor has been proposed to optimize the quantum of excessive sag and reduce it. The performance of the proposed controller has been compared with the performance of fuzzy logic controller, Neuro-fuzzy controller and conventional controller with the help of data collected from the plant. The simulation results depict that the proposed controller has superior performance than the other controllers.     

板带涂油机的发展与应用及国产静电涂油机的研制

介绍了机电一体化产品－板带涂油机的发展与应用概况，详细介绍了国产第一台静电涂油机的开发与研制以及它的组成及特点，展望了静电涂油机在国内的广泛应用前景。     

模糊神经网络法及其在缺陷模式识别中的应用

针对冷轧带钢表面缺陷图像模式识别中出现的问题,引入模糊模式识别和反向传播神经网络识别方法.在研究比较两种识别方法的基础上,利用模糊模式识别在剔除噪音数据和反向传播神经网络在模型拟合和非线性识别上的优势,提出一种新的模糊神经网络方法,并详细讨论了算法的结构特点及其实现方法.对五种出现频率较高的典型缺陷图像进行计算机实验研究,结果表明,该方法能对缺陷图像进行有效的识别,具有良好的性能.     

Bifurcation analysis of wrinkling formation for anisotropic sheet

Surface distortions in the form of localized buckles and wrinkles are often observed in the sheet metal forming process. In many cases the presence of wrinkles in the final praduct is unacceptable for the purposes of assembly. Because of the trend in recent years towards thinner gauges and higher strength, wrinkling is increasingly becoming a more common and troublesome mode of failure in sheet metal forming. In this study, a numerical analysis for evaluating a wrinkling limit diagram (WLD) for an anisotropic sheet subjected to biaxial plane stress is presented. Here the scheme of plastic bifurcation theory for thin shells based on the Donnell-Mushtari-Viasov shell theory is used. The effects of the various material parameters (yield stress, strain hardening coefficient and normal anisotropy parameter) and geometric parameters on WLD are investigated numerically and compared with Kawai's and Havranek's experiment(1975).     

带钢切边圆盘剪的使用及维护

圆盘剪是连续酸洗生产线中的重要设备,剪切质量的好坏直接影响到后续轧制工艺。重点分析了影响圆盘剪剪切质量的几个重要因素,总结了提高设备作业率的维护方法,并根据实际使用情况给出了一套最优参数值。     

旋转编码器在带钢边缘检测中的应用

介绍一种高精度旋转编码器的工作原理和特性 ,以及在带钢边缘检测中的应用。该编码器与可编程控制器、 CCD光电检测器构成高精度带钢纠偏控制系统。该系统具有控制精度高、响应速度快等特点 ,对高质量带钢的生产具有重大意义     

曲率半径的高精度测量及其不确定度

为了高精度测量光学元件的曲率半径,提出了一种利用反射式计算全息元件结合波长移相干涉测长技术测量光学球面曲率半径的方法.测试中,将反射式计算全息元件作为基准来标定所用标准镜头参考面的曲率半径,利用波长移相干涉技术测量干涉腔腔长,通过计算分析得到被测元件的曲率半径.文中描述了该方法的系统构成及其工作原理.结合实例,运用理论分析与软件仿真模拟分析了方法的测量不确定度.最后,利用实验室现有的商用波长移相干涉仪进行了实验验证.对一口径为100 mm的球面样品进行曲率半径的测量,得到的结果为157.108 3 mm;利用接触式球径仪法对同一样品进行对比测量,结果显示相对误差小于0.02％.与其它目前已有的非接触式曲率半径测量方法相比,提出的方法具有误差源少、测量精度高、易于操作等优点.     

热轧带钢轧后冷却倾翻支架结构分析及优化设计

为实现热轧带钢轧后冷却倾翻支架的轻量化设计,在对目前国内采用的主要设计结构进行结构受力分析的基础上开展了拓扑优化设计。首先利用UG建立倾翻支架的三维结构模型,然后采用ANSYS进行不同受力载荷工况下主要结构件的应力分布和位移变形情况模拟分析。结果表明,主动杆最大应力均集中在中间区域靠近中间轴的角点上,最大变形量发生在靠近液压缸的边缘处;立柱的最大应力发生在立柱底板上螺栓孔附近,最大变形量发生在施加力的作用面附近区域。最后针对主动杆和立柱进行了结构优化和验证分析,在确保优化前后应力值和变形量基本一致的情况下,主要结构的重量比优化前减轻了13%左右。     

A study on the annealing characteristics of BAF for cold rolled steel strip

The cold spot temperature control system for BAF (Batch Annealing Furnace) has been established in order to reduce energy consumption to improve productivity and to stabilize the properties of products. We improved material quality, increased output, and decreased the annealing cost and homogeneous distribution of cold spot temperature in BAF. The introduction of H₂ instead of N₂ as atmospheric gas, combined with high convection in BAF, has resulted in a considerable increase in furnace efficiency and material quality. By the low density, high diffusibility, and reducing character of H₂, a better heat transfer resulting in uniform material temperature and improved coil surface can be achieved. The results in this study are as follows: Heating time is reduced to one half by increasing the inflow rate of atmospheric gas and changing of atmospheric gas component from HN_x(H₂: 5 %, N₂: 95%) to Ax(₂: 75%, N₂: 25%) gas. The annealing cycle time is also reduced to 2.7 times. In the case of HNx BAF the cold spot moved to the center after 32 hours of heating, while in the case of H₂ BAF it moved from the one-third position of the B coli inside to the center juster after 12 hours of heating, resulting from a heat transfer increase to the radius direction. The temperature in this part is higher than any other parts when cooling. Soaking time at batch annealing cycle is decided by input coil width, and the time for quality homogenization of 1219 mm width coil must be longer by 2.0 hours than that of 914 mm width coil with the same coil weight at H₂ BAF, however, it is necessary to make 2.5 hours longer at HNx BAF.     

Advanced temperature control of high carbon steel for hot strip mills

In this paper, an advanced temperature control for the high carbon steel is proposed to obtain the desirable temperature and property of a steel on the run-out table (ROT) process. The temperature model based on the nonlinear heat transfer equation is described to predict the temperature of the steel at each position of the ROT. A cooling stop temperature (CST) concept is proposed to increase the volume fraction of the transformed phase for the high carbon steel. The concept is derived from a time-temperature transformation (TTT) diagram which is measured from the dilatometric experiment. The simulator using the temperature model is developed to achieve the desired temperature, and the effectiveness of the proposed control is also analyzed from the simulation. It is shown through the field test of the hot strip mill of POSCO that the performance with respect to the temperature and the property of the steel is greatly improved by the proposed control technology.     

彩色带钢辊涂机侧压辊装置

介绍了新疆八一钢铁艘份有限责隆公司彩色钢板厂带钢辊涂机侧压辊装置，设计思路及在辊涂机设备上增设侧压辊装置。     

Mathematical model for cold rolling and temper rolling process of thin steel strip

A mathematical model for cold rolling and temper rolling process of thin steel strip has been developed using the influence function method. By solving the equations describing roll gap phenomena in a unique procedure and considering more influence factors, the model offers significant improvements in accuracy, robustness and generality of the solution for the thin strip cold and temper rolling conditions. The relationship between the shape of the roll profile and the roll force is also discussed. Calculation results show that any change increasing the roll force may result in or enlarge the central flat region in the deformation zone. Applied to the temper rolling process, the model can well predict not only the rolling load but also the large forward slip. Therefore, the measured forward slip, together with the measured roll force, was used to calibrate the model. The model was installed in the setup computer of a temper rolling mill to make parallel setup calculations. The calculation results show good agreement with the measured data and the validity and precision of the model are proven.