四辊破碎机辊皮修复工艺改进

为提高四辊破碎机辊皮使用寿命,对辊皮堆焊修复工艺进行了改进,对车削装置的传动系统链轮进行了改造,车削装置由人工手动车削改为自动车削。改进后,辊子的更换周期由1.5个月延长到5个月,每年减少设备成本10万元左右。     

工作辊弯辊力对热轧带钢凸度的影响

为了建立高精度的热轧带钢凸度计算数学模型，采用影响函数法开发了四辊轧机热轧带钢凸度影响率计算软件；系统地研究了工作辊弯辊力对带钢凸度的影响规律。得出了工作辊弯辊力影响率基本值和工作辊直径、单位宽度轧制力、压下量对弯辊力影响率修正指数的6次项拟合系数，建立了高精度工作辊弯辊力影响率的计算模型。为优化板形控制参数提供了理论依据。     

CVC六辊冷轧机中间辊异常损伤探讨

通过对中问辊和工作辊的受力分析，探讨中问辊端部表面损伤的原因；提出改善中间辊端部受力状态、延长其使用寿命的措施。     

钢辊堆焊技术的发展

本文阐述了钢辊堆焊技术在国内外应用及研究的状况；着重论述和分析了我国钢辊堆焊的材料、设备、工艺和一些钢辊堆焊的实例；并就马钢如何进一步开展钢辊堆焊工作提出了几点建议。     

辊式矫直机辊径和辊距影响因素分析

辊径和辊距是辊式矫直机最重要的基本参数。从矫直质量出发，分析了咬入条件、接触应力和强度条件对辊径和辊距的影响。结果表明，强度条件是影响辊距和辊径的关键因素，是确定辊式矫直机辊径和辊距重点考虑的因素，其他因素可用来评价由强度条件确定的辊径和辊距的适用性。该结果对辊式矫直机的设计与开发具有指导意义。     

20辊轧机支承辊调整参数的研究

提出２０辊轧机支承凸度调节灵敏度的概念，分析了现有的凸度调节法；实验发现了现有调节方式的局限性，由此提出一个新的调节方式－－综合调节法。计算结果表明，用综合调节法可大幅度提高２０辊轧机的凸度控制能力，并可改善辊系的受力状况，从而提高轧辊及轴承的使用寿命。     

冷轧HC轧机支承辊剥落失效分析及改进措施

通过断口分析和使用情况分析，找出冷轧ＨＣ轧机支承辊６次剥落失效的原因，主要是支承辊与中间辊肩部相接触的辊面承受着较大的辊间接触压力；疲劳损伤；磨削量过小；轧钢量过大，并提出相应的改进措施。     

面向板形控制的辊型窜辊与弯辊技术应用

 根据板形控制理论和现场实际工况,研究了1 580 mm热连轧精轧机组机型配置,基于中值弯辊力,开发了与各机架机型适配的支承辊和工作辊辊型,扩大了弯辊力对辊缝的调节能力,建立起与工作辊辊型匹配的窜辊工艺制度,形成了正弦工作辊VCR支承辊、长行程窜辊和强力弯辊这3项控制的组合技术方案。生产实践表明,长行程WRS技术分散了轧辊热变形,使工作辊磨损曲线平缓、光滑,结合辊型与弯辊技术可以保持承载辊缝形状正常和可控,实现了热轧带钢板形和断面形状的良好控制。     

工作辊驱动UCM轧机支撑辊配辊策略

 轧辊是钢铁企业的重要消耗品,降低轧辊消耗是当前钢铁企业降本增效的要求之一。硅钢断带和粘钢容易引起支撑辊辊面掉肉及裂纹,造成支撑辊磨削差异大、配辊难。合理设计配辊辊径差可方便轧辊管理,减小支撑辊下机后不必要的磨削量,显著降低辊耗成本。但是支撑辊是影响轧制稳定性的重要部件,为此从动力学原理分析了工作辊驱动的UCM轧机上下支撑辊辊径差异对加减速过程驱动力矩的影响,根据弹性力学原理分析了上下支撑辊和中间辊压扁量差异对带钢厚度设定和控制精度的影响。生产应用最新配辊方案表明,合理的配辊策略不仅不会影响生产,而且方便轧辊管理,降低辊耗成本。     

六辊CVC平整机横向辊印缺陷分析与控制

为解决某厂六辊CVC平整机换辊后出现的横向辊印缺陷问题,采用三维光学轮廓仪对横向辊印缺陷样板进行了检测与分析,获得缺陷区域与正常区域的表征参数差异。研究了平整机辊缝闭合过程辊间接触压力分布,确定横向辊印缺陷的产生机理。在此基础上,提出了平整机中间辊CVC辊形优化与辊缝闭合过程参数优化解决方案,并应用于工业生产,消除了横向辊印缺陷。     

Asymmetric three-roller sheet-bending systems in steel-pipe production

Various attachments are used to produce components of particular configurations from metal sheet. In particular, sheet-bending roller systems may be classified in terms of the number of rollers (two, three, or four); the type of drive (mechanical, pneumatic, electromechanical, hydraulic); and the roller configuration (symmetric, asymmetric). Three-roller systems are used for the production of cylindrical, oval, and conical components by bending the metal sheet. They may be employed to manufacture pipes, channels, airways, shells, barrels, and sheathes. The operation of three-roller sheet-bending systems is based on the rotation of rollers in opposite directions, so that the sheet is captured and bent to the specified radius. To facilitate sheet supply and the release of the products bent into closed circles, the three-roller sheet-bending systems are combined with a removable front shaft applying a pressure that may be adjusted. In the three-roller systems, the diameter of the upper roller is about 1.5 times that of the lower rollers. In shaping, the rollers perform reversible motion. The upper roller may be raised and lowered to regulate the diameter of the circle produced. In this approach, extremely small sheet sections remain flat. This problem is eliminated by bending the ends of the sheet in a press or in a roller mill. In the present work, a mathematical method is proposed for determining the forces and torques in cold flexure of thick steel sheet on three-roller sheet-bending systems. The calculations permit the determination of the reaction of the roller supports, the residual stress in the wall of the steel sheet, the proportion of the plastic deformation over the sheet thickness, and the relative deformation of longitudinal surface fibers of the sheet in flexure as a function of the roller radius, the roller spacing, the reduction of the sheet by the upper roller, the sheet thickness, the Young’s modulus, the yield point, and the strengthening modulus of the steel sheet. The results may be used at metallurgical and manufacturing plants in the production of large-diameter steel pipe for major pipelines.     

铝合金踏板加工设备的设计探讨

从铝合金踏板的种类、连接方式入手,对加工建筑铝合金踏板所用的滚压机的设计进行了探讨,并重点分析了滚压机机械部分的动作顺序、液压部分油缸的选择、压辊的尺寸确定等问题。实测证明滚压后的踏板可以安全使用。     

Simplified calculation of the bending torques of steel sheet and the roller reaction in a straightening machine

In the straightening of steel sheet, it is necessary to calculate the optimal reduction of the steel blank by the working rollers of the straightening machine so that the sheet produced has the minimum residual stress and curvature. In the simulation of sheet straightening in multiroller machines, the curvature and bending torques of the steel sheet at contact points with the working rollers are first calculated and then the straightening forces are determined. In straightening steel sheet, it is important to calculate the forces in the multiroller straightening machine. Such calculations are based on determination of the reaction of the roller bearings and the forces at the upper and lower working-roller cassettes in straightening. With insufficient bending torque, it is impossible to eliminate harmful residual stress and surface defects in the sheet. Extreme roller torques and forces at the roller cassettes often lead to defects of the sheet, fracture of the working and supporting rollers, and failure of the straightening machine. In the present work, an approximate method is proposed for calculation of the optimal cold-straightening parameters of the steel sheet in a multiroller machine. The calculations permit determination of the curvature of the neutral plane in the sheet on straightening, the residual curvature of the sheet after straightening, the bending torque and the reaction of the working-roller bearings, the residual stress in the sheet, the penetration of the plastic deformation into the depth of the steel sheet, and the relative deformation of the longitudinal surface fibers of the sheet on straightening as a function of the radius of the working rollers, the distance between the rollers of the straightening machine, the reduction of the sheet by the upper rollers, the sheet thickness, and its properties (Young’s modulus, yield point, and strengthening modulus). The results may be widely used at manufacturing and metallurgical plants.     

影响铸轧铝板板形的因素及控制方法

研究了铸轧辊型、磨削正弦角、铸辊冷却水对铸板板形的影响机理和相应的控制方法,通过控制达到改善铸板横向板形、纵向板形的目的。     

薄板冷连轧机组轴承烧损的故障诊断

薄板冷连轧机组轴承烧损事故逐渐增多,造成经常停机更换圆锥滚子轴承。根据故障产生的特点,轴承烧损大多集中在轧制功率高的轧辊上。现场发现由于存在过大的轴向力,使得载荷集中到2列甚至1列轴承上。测量数据分析发现轧制时的轴向力随着轧机牌坊的磨损程度——轧辊与轧制中心线的倾斜程度加大。通过更换轧机牌坊的衬板,修复牌坊的几何尺寸,更换轧辊轴承箱的衬板,修复轧辊轴承箱的几何尺寸,使轧辊轴承的烧损下降到过去水准的三分之一以下,保证薄板冷连轧机组安全运行。     

Asymmetric deformation of metal and front flexure of thick sheet in rolling. Part 2

Laboratory experiments are followed by the rolling of sheet in industrial conditions on 3600, 2300, and 5000 thick-sheet mills. The parameters that affect the front curvature of the sheet leaving the rollers are identified. The sheet-reduction conditions on the 3600 and 2300 mills are assessed, so as to determine the rolling parameters responsible for asymmetry of the process in the vertical plane. Means of compensating the sheet flexure at the roller exit are proposed.     

金属薄板滚压冲裁过程数值模拟及模具参数

研究了在没有压下辊的情况下滚压冲裁过程的运动学特性,据此提出了通孔滚压冲裁模具的设计方案.在此基础上,利用ABAQUS有限元软件进行了基于Shear Failure韧性断裂准则和任意拉格朗日一欧拉自适应网格技术的45号钢薄板滚压冲裁过程有限元仿真,分析了主要参数对断面质量的影响.仿真结果表明:方形孔滚压冲裁时,前后刃口依次经历板带弯曲、凸模压入、裂纹产生和发展、断裂和凸模拔出五个阶段;滚压冲裁断面的主要质量缺陷包括断面垂直度、毛刺、塌角、压痕等;影响滚压冲裁断面质量的主要因素包括侧隙、凸模高度、辊子半径等.减小标称侧隙和凸模高度、增大辊子半径均会使断面质量提高,其中又以对断面垂直度和毛刺高度的影响更为明显.对于45号钢一类的碳钢,后刃口标称侧隙以板厚的5%-10%为宜,前刃口标称侧隙可以更小:辊子半径应以大于板厚的100-150倍为宜;在保证板材完全断裂的前提下,应使凸模高度尽量减小.      

铸轧辊辊型控制的探讨

铸轧卷的板形质量主要取决于铸轧辊的辊型条件、速度、冷却强度 ,本文对铸轧卷纵向、横向板差及板形情况进行了全面分析 ,找出了铸轧辊辊型影响铸轧卷板形的原因并提出了解决办法     

无取向硅钢异步冷轧织构沿厚度的演变

对2.2 mm厚常化后无取向硅钢(%:0.004C、3.1Si、0.33Al),以速度比为1.19异步轧制到0.5 mm厚,用取向分布函数(ODF)定量研究了异步冷轧织构沿厚度的变化。结果表明:常化后的无取向硅钢板材沿厚度方向的织构类型发生了明显的变化,中心侧反高斯织构较强,在异步冷轧后继续保持了这种状态,而表层和次表层高斯织构在冷轧后消失;冷轧后板材在快慢辊侧的织构类型没有变化,但强度发生明显的变化;异步冷轧织构沿厚度方向呈非对称分布;反高斯织构在慢辊侧的强度高于快辊侧的强度,{111}〈112〉织构出现中心低两侧高的现象,慢辊侧略高于快辊侧。     

轧辊温度场及轴向热凸度有限元计算

采用大型有限元分析软件 ANSYS对四辊轧机工作辊的温度场进行了模拟 ,在模拟过程中 ,考虑了轧辊和轧件间的瞬态热接触和对流边界 ,动态分析了热轧时工作辊的升温过程 ,预测了工作辊的瞬态温度分布 ,并将所得的温度分布用于热凸度的近似计算中 ,其计算结果与文献结果相吻合