冷轧乳化液铁粉颗粒对摩擦系数的影响

 乳化液在轧制过程中主要起润滑和冷却的作用,其性能对保证带钢轧后的表面质量起到至关重要的作用。乳化液的润滑作用主要体现在轧制过程中带钢和轧辊之间形成一层油膜,使得带钢表面和轧辊之间的润滑处于液体润滑状态,在降低轧制过程摩擦系数的同时,降低轧辊的磨损。在实际的轧制过程中,经长期使用后,乳化液中混入大量的铁粉和其他杂质,使乳化液的润滑性能发生了改变,从而对轧制摩擦系数产生影响。通过试验研究,发现乳化液铁粉含量、铁粉颗粒直径的变化对软带钢表面摩擦系数影响显著,对硬带钢表面摩擦系数影响甚微。     

首钢京唐1420高速薄板轧制润滑工艺研究

介绍了乳化液的润滑机理,阐述了边界润滑、混合润滑、弹性流体润滑等润滑形式的内涵,及辊缝区的成膜特点,分析了首钢京唐1420酸轧因润滑问题造成的划伤、暗线及色差等典型的带钢表面缺陷。随着轧制速度的增加,辊缝区域中的油膜厚度也增加;但当速度超过一定值时,乳化液的油膜厚度将会随之下降。高速轧制下,乳化液的润滑形式为弹性流体润滑,其会使带钢处于自由变形的状态,容易产生塑性粗糙化,同时易在带钢表面产生划伤、暗线及色差等缺陷,应尽量避免。     

铜带冷轧乳化油的配方研制及润滑效果评价

根据亲水亲油平衡理论,通过选择合适的基础油、乳化剂、极压剂、抗磨剂、防锈剂等添加剂,研制了适用于冷轧铜带所需的CO-1冷轧乳化液,并成功地应用于冷轧铜带工业实验。研究了CO-1乳化液在铜带冷轧时对轧机主电机电流和轧后铜带表面质量的影响。与某国外商品级冷轧乳化液(SO-1)进行了对比轧制实验。研究结果表明:由于采用了CO-1乳化液润滑,在实验中轧制压下率增加,主机工作电流降低;并且乳随着轧制力增大,CO-1乳化液润滑效果更加明显;同时稳定的改善了铜带轧后表面质量。     

2180mm酸轧机组带钢表面水印形成原因及控制

随着河钢集团邯钢公司产品转型升级，带钢表面质量要求越来越高，而轧后带钢表面水印则成为产线经济效益提升的制约。本文从热轧原料、轧辊表面质量、辊缝润滑、乳化液浓度、轧制策略、压下分配等工艺方面，系统地分析了邯钢2 180 mm酸轧机组带钢表面水印的形成原因，认为水印缺陷主要由带钢表面粗糙度均匀性太差、轧辊粗糙度在带钢表面不均匀复制所致。通过降低轧辊表面粗糙度，提升轧辊粗糙度RPC,降低F5机架压下率，提升末机架乳化液浓度，加强轧辊喷嘴检查，提高原料表面质量等措施，轧后带钢表面水印缺陷得到有效控制，为后序生产汽车外板创造了基础条件。     

冷轧轧制油抗杂油性能研究

杂油是影响冷轧轧制油乳化液性能的主要污染物之一,含杂油过多的乳化液将直接影响轧制生产润滑及轧后产品表面质量,因此测试轧制油的抗杂油性能十分重要。就冷轧不同种类及不同含量的杂油对乳化液的理化性能、稳定性、润滑性能以及热挥发性能的影响进行了分析测试。试验结果表明,液压油、油膜轴承油对乳化液的理化性能、润滑性能的影响基本一致,而液压油比油膜轴承油对乳化液的稳定性以及热挥发性能的影响更大。总体而言,杂油含量控制在20%以内是比较安全的,最大不能超过30%。     

渗透探伤法在连轧坯和钢板表面质量检验中的应用

利用表面渗透探伤法对高碳钢连轧坯和轧后钢板的表面质量进行了检验,并且对缺陷形貌和来源进行了分析。结果显示,表面渗透探伤法能准确确定连轧坯和轧后钢板表面缺陷的位置。与酸浸法相比,表面渗透法更加直观、准确。     

轧制时变形区内油膜厚度的研究

变形区内油膜的建立及厚薄,直接影响接触偶间的摩擦性质,是轧制过程摩擦与润滑机理的基本问题之一。同时,油层的厚薄还影响变形区内摩擦系数、摩擦力和轧制压力大小以及产品表面质量优劣。一、油膜测量方法采用秤重法测量油膜厚度。首先,用汽油、丙酮等挥发性溶剂清洗、擦净轧辊与轧件表面。干燥后,将润滑油滴至试样表面,轧后秤其重量(W_1),再用求积仪测得油     

单机架冷轧机工艺润滑系统改进及优化

针对单机架冷轧机乳化液系统运行中存在的乳化液浓度异常波动、带钢表面残留量大等问题,对系统供液管道、乳化液箱体及辅助设施进行了改造。改造后乳化液浓度变化趋于稳定,同时钢板表面残油量从最高673.5 mg/m2降低到223mg/m2,带钢表面质量得到改善的同时轧制油耗大幅降低。     

提高冷轧钢板表面清洁度措施

针对不经电解清洗的冷轧带钢如何提高表面清洁度进行了研究,详细分析了乳化液对轧后钢板表面残留物的影响及罩式退火工艺对成品钢板表面清洁度的影响,提出了改善罩式退火后钢板表面清洁度的有效措施。     

油粘度对冷轧不锈钢带表面粗糙度的影响

采用不同粘度的冷轧油，研究了轧制成形过程中润滑油膜对不锈钢轧后表面粗糙度的影响。轧制实验表明：油膜厚度减少有利于不锈钢带轧后表面质量的改善。     

3+1型乳化液系统工艺润滑制度优化设定技术

为了研究配置3+1型乳化液系统的冷连轧机组生产不锈钢产品因轧制变形区欠润滑、过润滑以及冷却不足等导致冷轧带钢上表面和下表面质量差异的问题,以某钢厂新建六机架冷连轧机组为研究对象,从乳化液工艺润滑的角度出发,介绍了该机组3+1型乳化液工艺润滑系统布置,分析了工艺润滑制度参数对轧制稳定性的影响因素.通过揭示乳化液浓度、温度...     

A new cold rolling lubrication method combining emulsion and neat oil lubrication

The cooling and lubrication process is one of the key processes in cold rolling,as it not only determines surface quality and strip shape,but also reduces the rolling power consumption and extends the life of the roll even during high-speed operation.In this study,an innovative method combining emulsion lubrication and neat oil lubrication was used to solve some problems associated with individual passes.Laboratory tests on stainless steel strips showed that this new lubrication method could improve the surface quality of the strip,control the rolling friction in the deformation zone,and has the potential of making lubrication systems simpler and easier to operate, all while reducing the negative environmental impact from emulsion processing.     

Prediction and Control of Thermal Scratch Defect on Surface of Strip in Tandem Cold Rolling

The thermal scratch significantly influences the surface quality of the cold rolled stainless steel strip.In order to establish a precise mathematical model of oil film thickness in deformation zone,the lubrication in cold rolling process of B443 NT stainless steel strip was studied in the laboratory.According to the principle of statistics,a mathematical model of critical oil film thickness in deformation zone for thermal scratch was built,with fitting and regression analytical method,and then based on temperature comparison method,the criterion for deciding thermal scratch defect was put forward.Storing and calling data through SQL Server 2005,a software on thermal scratch control was developed in the Microsoft Visual Studio 2008 environment by MFC technique for stainless steel in tandem cold rolling,and then it was used into the practical production.Statistical results demonstrated that the hit rate of thermal scratch arrives at 91.47%,the occurrence rate of thermal scratch is decreased by 87.81%,and rolling speed is increased by 7.3%.The developed software is of significance to the control of products quality of stainless steel strips,and the analysis and solution to the problem of thermal scratch defects in tandem cold rolling.     

新型冷轧轧制油AZ01的研制

通过选择合适的基础油,添加防锈剂、极压剂、乳化剂、抗磨剂、表面活性剂及抗氧化剂等添加剂,研制出一种新型的冷轧轧制油AZ01。研究了AZ01对轧制力和轧后带钢表面质量的影响,并与进121冷SLSL制油（ST01）进行了对比轧制试验。试验结果表明,AZ01的轧制力低于ST01,润滑效果好于ST01。使用后性能稳定,其轧后钢板表面的残铁及残油含量略低于ST01的相应指标。     

不锈冷轧带钢表面光洁度的控制

在生产中，不锈冷轧带钢的表面光洁度一般用粗糙度进行控制，其粗糙度越低，光洁度越高。应使用低粗糙度和低微小缺陷面积率的不锈热轧带钢，高的总压下量，低粘度轧制油和平整率达到1％的工艺轧制可获得较高光洁度的不锈冷轧带钢。高速钢轧辊轧制的不锈冷轧带钢的光洁度优于模具钢轧辊。     

Developments of work roll bite lubrication at SSAB Tunnplåt AB hot strip mill

In the strip rolling process friction is needed at first to pull the strip into the roll gap, otherwise slipping occurs. After the neutral plane however, where the velocity of the work roll equals the velocity of the strip, the friction stress alters direction to the opposite. If the friction stress after the neutral plane then is lowered, the total roll force will decrease. This can be done by a properly applicated oil- and water dispersion close to the work roll gap and between the roll cooling wipers. The technique and the key to a successful lubrication is a work roll surface which is as dry as possible. If the roll surface is not dry, neither large changes in the oil concentration, nor changes in the oil composition can make the lubricant stick to the roll surface. The lubricate was partly washed away by the water and only a small roll force decrease could therefore be measured. Only when the roll cooling water on the entry side of the work roll was set off on purpose, the roll force decrease was significant. Due to this result, further test were performed in an upstream stand in the hot strip mill. Here, the work roll wipers were modified and the roll was substituted by one with a larger radius and lubricated. The result was very slight or no water leakage at all. The roll force decrease was then much greater than before and close to those measured for the same reduction in the case of no entry water for the later stand. The electrical current in main drives and the roll wear in the lubricated stand could also be lowered significantly. In addition, the strip surface was greatly improved, under conditions with a high possibility of oxide residual contamination from the roll surface.     

二次冷轧机组带钢下表面润滑工艺补偿技术

 为了解决二次冷轧机组轧制过程中带钢上、下表面油膜厚度存在差异的问题,通过分析油膜厚度形成与演变机理,建立了二次冷轧机组带钢上、下表面析出油膜厚度计算模型。在此基础上,采用增加带钢下表面乳化液流量和乳化液配比浓度的方法,开发出一套二次冷轧机组带钢下表面润滑工艺补偿技术。通过该技术实现了二次冷轧机组带钢上、下表面轧制变形区油膜厚度均等的目标,同时,最大程度降低了带钢表面条状斑迹缺陷的发生率。并将该技术应用到国内某钢厂1 220二次冷轧机组,应用效果显著,典型钢种带钢上、下表面条状斑迹缺陷发生率大大降低,降低程度均在50%以上。     

纳米TiO2轧制液对硅钢冷轧性能的影响

分别采用传统冷轧轧制液和纳米TiO₂的冷轧轧制液,对无取向硅钢板进行了四辊冷轧实验.重点研究两种冷轧轧制液的轧制润滑性能和对轧后硅钢薄带表面质量和耐蚀性能的影响.通过场发射电子显微镜和能谱仪对使用两种轧制液轧后得到的硅钢薄带表面形貌和成分进行了分析.给出了轧制液中TiO₂纳米粒子在轧制过程中的抗磨减摩机理.在轧制载荷较高时,纳米TiO₂轧制液具有优良的轧制润滑性能并能显著改善轧后硅钢薄带的表面质量.同时在高载荷作用下,TiO₂纳米粒子被压入硅钢薄带基体,形成一个滑动系来支撑载荷,从而使润滑膜的耐磨性提高.      

提高轧后带钢表面清洁度的措施

通过对影响带钢表面清洁度的各种因素进行分析,提出了提高油品的润滑性能和清洁性以及优化乳化液系统等措施,生产实际应用后轧后带钢表面清洁度得以改善,带钢表面反射率由50%提高到61%.