带钢在线检测的新方法

在世界钢产量中,宽带钢的产量呈不断上升的趋势,其检验水平和产品质量也得到了明显改善。近几年来,人们已经做了很大努力,用无损检验方法对带钢进行检验,以保证其无缺陷存在。目前,这方面的情况已经发生了根本的改变。连铸技术在板坯浇铸上的应用促进了板坯质量的显著提高。一种精密可靠的程序加工技术能够生产出在整个长度、宽度和厚度     

带钢在线检测新系统

1 热带轧机在线检测新设备 图1是安装于Hoesch钢铁公司热带轧机上的新的检测及控制系统的示意图。 1.1 粗轧机的板坯尺寸控制 实践表明,热带的断面厚度及宽度是热轧带钢粗轧机组所要控制的基本参数。 为获得恒定的宽度,必须具备一种特殊的带钢头部及尾部的控制模型。在配套使用宽度光测系统时,要特别考虑立轧和平轧的影响。     

基于位置交叉点的脉冲涡流缺陷定量检测技术

在采用脉冲涡流技术的腐蚀缺陷定量检测中,由于传感器在缺陷区域某些扫描位置的感应信号会出现振荡,使得特征量难以提取,影响检测效果。为此提出了“位置交叉点”这一新特征量。试验结果表明,此特征量消除了信号振荡对特征提取的影响,具有稳定可靠的优点,可提高缺陷定量检测的精度。     

带钢卷取对边电液伺服系统分析

介绍了太原钢铁集团轧钢车间的一套带钢卷取边缘纠偏控制设备(EPC),分析了其电液伺服系统原理和数学模型,并进行了稳定性分析.     

脉冲涡流检测中传感器空间位置变化对检测结果影响规律的仿真分析

在脉冲涡流检测中,为了研究传感器空间位置变化对检测结果的影响规律,通过AN—SYS有限元仿真的方法,分析了传感器水平和垂直位置变化对感应电压信号及缺陷附近电磁场分布的影响。仿真结果表明,传感器位于水平及垂直方向的不同检测位置时,前者可通过感应电压得到峰值时的检测位置,实现对缺陷的边缘检测,后者的感应电压信号具有提离交叉点。仿真结果为试验研究传感器空间位置变化对检测结果的影响提供了理论指导。     

热带轧机中带钢位置和弯曲度的监测

正德国EMG集团与塔塔钢铁集团共同开发了一种光学摄像系统,即hotCAM,用于对热轧板坯和带材位置及弯曲度的监测。带钢在机架之间保持确定的位置对于热轧过程安全十分重要。对带钢位置的连续监测可使轧制力和辊缝的调节最佳化,减少带钢的弯曲度,防止带钢与导卫装置的碰撞。hotCAM将带钢边部的位置数值以±2mm的精度连续输入到控制系统,操作人员可以采用这些信息进行闭环控制     

激光热轧板带钢板形检测方法的研究

本文研究的新型激光板形检测方法是利用棒状激光器、CCD成像技术和数字图像处理技术非接触式检测热轧板带钢板形的方法.本文论述了该测量方法的工作原理和所进行的模拟检测试验.测量结果表明,该方法测量热轧板带钢板形结果准确可靠.     

欧美宽带钢常规流程直接轧制技术

分析了欧美直接轧制技术的主要对策，针对速度补偿、温度补偿、缓冲，过程控制和性能预报等措施加以论述，提出可行的直接轧制方案。     

管道腐蚀检测中新型脉冲涡流传感器的设计

提出了一种新型脉冲涡流传感器设计思路。它将脉冲涡流激励场从空间上转化为匀强涡流场,从而等效为一种自差分式的涡流检测技术,因此无需进行差分处理,可避免差分信号的不同步导致的检测精度和灵敏度不高。采用该新型脉冲涡流传感器对钢管腐蚀缺陷进行了检测,试验结果表明设计的传感器具有较高的灵敏度和检测精度。     

一种通用的电液伺服带钢纠偏和对中控制系统

本文分析了带钢生产线上纠偏控制系统与对中控制系统的不同,介绍了一种通用的带钢纠偏和对中控制系统的特点、组成、工作原理、过程和功能，经生产实践表明该系统工作稳定、运行可带、抗污染性强、具有良好的应用前景。     

Subpixel accuracy for extracting groove center based on corner detection

Subpixel accuracy for V-groove center in robot welding is researched and a software measure to increase the accuracy of seam tracking by laser is presented. LOG （ Laplacian of Gaussian ） operator is adopted to detect image edge. Vgroove center is extracted by corner detection of extremum curvature. Subpixel position is obtained by Lagarange polynomial interpolation algorithm. Experiment results show that the method is brief and applied, and is sufficient for the real time of robot welding by laser sensors.     

主动式电磁检测技术理论研究

针对传统电磁检测技术不能适应复杂环境下工件缺陷检测的情况,提出了主动式电磁检测技术,该技术能根据工件厚度对装置进行主动调整。在设计主动式电磁检测装置的基础上,重点对其中的工件厚度测量方法进行研究。建立了基于透射式涡流检测的工件厚度测量模型,利用Matlab软件对模型进行仿真分析,最后搭建实验平台进行两组工件厚度测量实验,对比实验检测结果与理论计算值,两组实验检测误差分别为0.76%及1.46%。仿真及实验结果表明:基于透射式涡流检测建立的工件厚度测量模型是可行的。     

Pulsed electromagnetic methods for defect detection and characterisation

The magnetic flux leakage (MFL) method has very good defect detection and location capabilities, but defect sizing capabilities, especially for sub-surface defect characterisation, are limited. The pulsed magnetic flux leakage (PMFL) technique has recently been introduced and shown to have great potential for automated defect sizing for surface-breaking defects using time-frequency signal processing techniques, but sizing of sub-surface defects has proved problematic. In this paper, pulsed magnetic reluctance (PMR), a new electromagnetic (EM) non-destructive evaluation (NDE) technique, is introduced and incorporated into a dual PMFL/PMR probe for the characterisation of surface and sub-surface defects in ferromagnetic materials. Experimental results from a comparison study of the two techniques using variety of defects analysed using time-frequency analysis show that the techniques offer complementary information, with PMFL providing defect location data and data for the characterisation of surface defects and PMR offering sub-surface defect characterisation capabilities. The work concludes that integration of these inspection techniques in the new pulsed EM probe can provide enhanced defect characterisation capabilities for flux leakage-based inspection systems using relatively simple time-frequency signal processing techniques.     

空间位置精密检测技术在主轧机设备管理中的应用

针对秦皇岛首秦金属材料有限公司4 300 mm生产线主轧机在使用过程中出现的异常振动、异响、钢板跑偏甩弯问题,利用精密摄影测量系统、精密全站仪等检测技术对主轧机空间位置进行检测,通过对检测数据的分析发现设备在空间位置上存在超出标准的偏差,采取措施后取得了良好效果。     

一种基于梯度直方图的焊缝边缘检测方法

焊缝边缘检测技术是图像分析、图像理解的最基本操作之一,也是焊接机器人实现焊缝跟踪的关键技术之一。基于梯度直方图提出一种焊缝边缘检测方法,将二维高斯滤波器分为水平和竖直方向的一维高斯滤波器对图像进行平滑处理,然后用一种改进的梯度计算方法来计算梯度和确定像素点梯度方向。最后采用梯度统计量进行阀值选取,并结合非极大值抑制得到单像素宽的边缘图像。将二维高斯函数和梯度的计算由二维降到一维,减少了计算量,同时由于不同的梯度值直接与相应的方向对应,因而在后续的处理中无须再进行梯度方向的计算,提高运算的效率,阈值选取具有一定的稳定性。运用MATLAB软件对图像进行处理,对比经各种算法处理的焊缝图像说明该算法具有较好的适应性和鲁棒性。     

基于改进PSO神经网络的板形板厚解耦控制研究

针对板形板厚综合系统具备强耦合、非线性、大时滞等特性,传统的控制方法无法对其完成精确解耦,导致控制精度较低。提出一种基于免疫机制的改进粒子群算法,同时借助此算法来优化处理PID神经网络(PIDNN),形成新型PIDNN控制器。利用两个PIDNN解耦控制器对板形板厚综合系统进行控制以降低系统耦合影响。通过仿真结果可以看出,在动态性能与静态性能上,此算法较以往PIDNN解耦控制均存在明显优势。可为控制领域中的解耦问题提供一定的参考。     

A three-dimensional finite element method for a nonisothermal aluminum flat strip rolling process

The purpose of this study is to develop a three-dimensional coupled thermo-elastic-plastic finite element model of nonisothermal rolling and analyze the strip curvature caused by the difference in the heat transfer boundary conditions of the upper and lower rollers. The difference in the rotation speed between the upper and lower rollers was utilized in an attempt to correct the aforementioned curvature in hot rolling due to unsymmetrical cooling conditions. In addition, the changes in shape, temperature field, and strain field of the strip during the various stages were analyzed and can be used to obtain the lateral plastic flow of the strip. As for the aspect of heat transfer, the various possible boundary conditions in the actual hot rolling were considered, which include the convection boiling of the air and water, and the radiation loss. Then, the three-dimensional finite difference heat transfer equation is derived according to the concept of heat balance. As for the determination of the direction of tangential friction force, this study also developed a modification algorithm to adjust to the three-dimensional rolling process. After a comparison with the experimental data in Ref 8 and 15, and the simulated temperature distribution in Ref 17, the partial results obtained from the computation by the numerical analytical model verify that the theoretical model and computer programs established in this study are reasonable. This study shows that hot rolling can greatly reduce the rolling force and strain rate with the early appearance of plastic deformation, and the distribution of temperature field is basically affected by the heat transfer boundary conditions. However, unsymmetrical heat transfer boundary conditions will cause unsymmetrical rolling forces of the upper and lower rollers and cause strip curvature; this condition can be corrected by the difference in the rotation speed of the rollers.     

A normalization procedure for pulse thermographic nondestructive evaluation

Pulse thermographic nondestructive evaluation (TNDE) technique can be used to estimate defect dimensions, and in particular the depth at which the defect is located. Numerical models of this procedure can aid in the interpretation of experimental results. However, the thermophysical properties of the test object as well as the amount of energy absorbed during this process are not readily available for such models. This paper presents an extension of the thermographic signal reconstruction (TSR) procedure in which the temperature and the time scales are respectively normalized with equilibrium temperature and the break time. In the normalized form these profiles are independent of material properties and instrumentation settings. Thus in the normalized format, experimental results can be readily compared with numerically generated thermographic results. The defect depth can also be easily obtained as a fraction of plate thickness from this plot.     

基于小角度纵波检测技术的钎焊界面缺陷检测

基于超声小角度纵波检测技术，采用非接触聚焦直探头，调节合适的声束入射方向，提取钎焊界面的超声反射信号，利用超声信号特征幅值来识别缺陷并完成超声成像，判断钎焊界面是否存在缺陷。3种样品的钎焊界面状态分别为焊接良好、存在人工缺陷和存在工艺缺陷，且检测样品表面所在平面与钎焊界面所在平面的夹角均为7°。检测结果表明：针对检测样品的最佳入射角α为4°，该方法可有效检出当量直径2.0 mm人工缺陷和钎焊界面工艺缺陷，成像结果能够准确并直观地判断出钎焊界面缺陷。最后，通过检测样品解剖分析验证了小角度超声纵波检测技术对钎焊界面缺陷检测的准确性。