Expert Experience and Data-Driven Based Hybrid Fault Diagnosis for High-SpeedWire Rod Finishing Mills

The reliable operation of high-speed wire rod finishing mills is crucial in the steel production enterprise.As complex system-level equipment,it is difficult for high-speed wire rod finishing mills to realize fault location and real-time monitoring.To solve the above problems,an expert experience and data-driven-based hybrid fault diagnosis method for high-speed wire rod finishing mills is proposed in this paper.First,based on its mechanical structure,time and frequency domain analysis are improved in fault feature extraction.The approach of combining virtual value,peak value with kurtosis value index,is adopted in time domain analysis.Speed adjustment and side frequency analysis are proposed in frequency domain analysis to obtain accurate component characteristic frequency and its corresponding sideband.Then,according to time and frequency domain characteristics,fault location based on expert experience is proposed to get an accurate fault result.Finally,the proposed method is implemented in the equipment intelligent diagnosis system.By taking an equipment fault on site,for example,the effectiveness of the proposed method is illustrated in the system.

Force Analysis and Curve Design for Laying Pipe in Loop Laying Head of Wire Rod Mills

Laying head is a high-precision engineering device in hot-rolled high speed wire rod production line. Previously research works are focused on the laying pipe wear-resisting. Laying pipe curve design method based on wire rod kinematics and dynamics analyses are not reported before. In order to design and manufacture the laying pipe, the motion and force process of the wire rod in the laying pipe should be studied. In this paper, a novel approach is proposed to investigate the force modeling for hot-rolled wire rod in laying pipe. An idea of limited element method is used to analysis and calculates the forces between laying pipe inner surface and wire rod. The design requirements of laying pipe curve for manufacturing are discussed. The kinematics and dynamics modeling for numerical calculation are built. A laying pipe curve equation is proposed by discussing design boundary conditions. Numerical results with di erent laying pipe curves design parameters are plotted and compared. The proposed approach performs good result which can be applied for laying pipe curve design and analysis for engineering application.

Present situation and countermeasure of low-alloy spring steel wire rod for domestic automobile

The variety,inner quality and surface quality of low-alloy spring steel wire rod for domestic automobile is summarized in detail.And according to commercial low-alloy spring steel wire rod variety, product quality level and its actual application situation on automobile supplied by present industrially developed country metallurgy enterprises,it is pointed that the variety of low-alloy spring steel wire rod for domestic automobile can't satisfy the requirements of automobile industry development,compare with overseas advanced technology,product quality has the following gaps:the first is that steel purity is low,the control level of non-metallic inclusions is not steady,there is often large grain difficult deforming non-deformation inclusions existing,the control level of steel purity has big difference,the level of large steel factory is high,but its steady has a large gap compare with foreign advanced level,not to mention small steel factory which research and development powder is low.The second is surface complete decarburization can' t be avoided completely.The third is that surface defects are more.The fourth is that composition segregation and structure segregation are not steady,steel wire can't be drawn normally when the segregation is serious. In all,the segregation of 55SiCrA is superior to 60Si2MnA obviously.The industrialization of domestic high level low-alloy spring steel wire rod can't seek quick success and instant benefits,independent innovation perseveringly must be adopted,the success may be reached after master core technologies and adopt the science way of step by step.

High-Speed Wire Rod Finishing Mill

The high-speed wire rod finishing mill production line consisting of more than 10 key items of equipment such as a heating furnace,major rolling mill, secondary rolling mill,preliminary refining mill, finishing mill, carrier roller, wire-drive machine, coiler, and packing machine, is a technology-intensive product combining modern rolling technology with the high-technology of machinery, electronics,hydromatic drive and instrumentation, which only a few countries in the world can produce.

Improvement of Inner Quality of High Carbon Wire Rod Steel Using Combined Electromagnetic Stirring

To improve the quality of high carbon wire rods,combined electromagnetic stirring was introduced in the continuous casting of round billets with a diameter of 250mm at Tianjin Rockcheck Steel Group Co.In this paper,the positioning of final electromagnetic stirring(F-EMS)was determined by nail-shooting method.Furthermore,the effect of mold electromagnetic stirring(M-EMS)on the macrostructure and internal defects in the round billets was investigated to find out the optimal operating parameters for continuous casting of SWRH 82B round billets.The results show the desirable positioning of F-EMS locates 9.7m below the mold level where the molten steel can be effectively driven by electromagnetic force and disperse central composition segregation.The shrinkage cavity is totally eliminated with the rotational M-EMS.The ratio and index of central composition segregation and center porosity can be reduced significantly. Furthermore,the equiaxed crystal ratio is considerably increased to 64%under 480A/3Hz M-EMS and 500A/10Hz F-EMS. Fine microstructure and mechanical property of wire rod are presented after optimization of combined electromagnetic stirring.Accordingly,the probability of occurrence of cup-cone fracture of wire rod is reduced dramatically.

The Effect of Microstructure of Hot Rolled Alloy Steel Wire Rods on Cold Heading Annealing Process

Cold heading carbon steels for 8.8 grade fasteners are mostly produced by pouring reel or spooler plant.Currently,with improvement of cold heading equipment,the 10.9 grade fasteners produced by cold heading have replaced most of hot forged fasteners gradually.As well known,wire rod coil has been used to produce alloy steels.The properties and microstructures of medium carbon alloy steels,such as B7,ML40Cr and SCM435,produced by wire rod coils under hot rolled condition and after spheroidization,have been investigated.In this paper,the effect of microstructure of hot rolled steel wire rods on cold heading annealing process was studied.The results show that the hardness of wire rod coil products is generally lower than that of bar products by 5 ～ 10 HRB and the ferrite fraction in wire rod coil products is higher.After spheroidization treatment,the hardness value and spheroidization grade of wire rod coil products are relatively low.alloy steels of wire rod coils can be directly drawn slightly and the annealing time can be reduced at the same time.This practice is much helpful for energy conservation.

Modeling and finite element analysis of rod and wire steel rolling process

Two thermomechanical coupled elastic-plastic finite element （FE） models were developed for predicting the 12-pass continuous rolling process of GCrl 5 rod and wire steel. The distances between stands in the proposed models were set according to the actual values, and the billets were shortened in the models to reduce the calculation time. To keep the continuity of simulation, a technique was developed to transfer temperature data between the meshes of different models in terms of nodal parameters by interpolation functions. The different process variables related to the rolling process, such as temperature, total equivalent plastic strain, equivalent plastic strain rate, and contact friction force, were analyzed. Also, the proposed models were applied to analyze the reason for the occurrence of an excessive spread in width. Meanwhile, it was also utilized to assess the influence of the roll diameter change on the simulated results such as temperature and rolling force. The simulated results of temperature are found to agree well with the measured results.

The Quality Specifications of Mischmetal Wire and Rod and the Method of Adding Rare Earth in Steel

The quality of mischmetal wire and rod and the method of adding rare earth into steel are quite important for making high quality steel. This paper proposes a quality specification of wire and rod as well as related adding method. The paper also provides principles for selecting raw material and adding method.

Influence of Wires Properties on Warp-Knitted Loop Geometry in Plane Based on Theory of Elastic Rod

Based on classic theory of elastic rod,the warp-knitted loop geometry in plane is independent of yarn properties,while there is a certain gap between the geometrical model and the actual fabrics.According to this problem,further analysis of loop geometry is done based on the theory of elastic rod with theoretical calculation and experiments.The theoretical analysis found that the distance between the contacted points at the loop root affected the loop geometry,and the distance was affected by the ratio of bending rigidity and the friction between yarns.The experiments,forming simple loop by taking the yarn as an elastic rod,found that the bending rigidity affected the loop geometry.Then the relationships between warp-knitted loop geometry in plane of metallic fabrics and wires properties were studied.The results show that metallic fabrics are more suitable for the theory of elastic rod;the friction and bending rigidity of wire yarns affect the loop geometry in plane.Also,the elongation of yarn affects the loop geometry in the actual warp-knitted fabric.

绕丝棒束组件过渡流摩擦阻力实验研究

绕丝棒束组件低流速下摩擦阻力是钠冷快堆堆芯热工水力研究的重点内容之一。通过对现有组件摩擦阻力系数公式应用于过渡流存在的问题、现有组件摩擦阻力实验在低流速时出现的不同摩擦阻力特性的分析讨论,以及对一个37棒组件低流速摩擦阻力的实验研究,提出了组件内流动的转捩特性和提高经验公式在低流速时计算准确性的有效策略。研究结果表明:绕丝棒束组件内流动转捩并不是同时发生,而是在部分子通道的局部先发生,随着流速的增加扩散到整个组件,只有当一定数量子通道都发生转捩时,棒束的平均摩擦阻力才会显著增加。绕丝棒束组件摩擦阻力系数公式应尽可能使用小的层流向过渡流转捩的临界Re和插值指数,使公式尽早开始转捩,并平滑向过渡流过渡。

BWR4耐候钢热轧盘条的研制开发

主要介绍了首钢长钢公司采用转炉、LF精炼炉、小方坯连铸机和55万t棒线复合产线工艺路线生产BWR4耐候钢热轧盘条的关键工艺技术。轧制盘条力学性能稳定,1/3冷顶锻合格率为100%,耐大气腐蚀指数在6.54以上,轧制盘条质量指标符合《耐候钢结构紧固件用热轧盘条及圆钢》标准要求,可满足用户加工5.8级螺栓使用要求。

70^(#)钢热轧盘条拉拔断裂的原因分析

70^(#)钢热轧盘条用于拉拔加工成多种钢丝产品,因此要求其具有良好的拉伸性能。但是,在实际生产中,某些因素通常会导致70^(#)钢热轧盘条抗拉强度降低,在拉拔过程中发生断裂,严重影响其产品质量,造成了巨大的经济损失。针对70^(#)钢热轧盘条在使用过程中出现拉拔断裂的问题,采用光学显微镜、扫描电子显微镜(SEM)、电子探针(EPMA)等检测设备分别从断裂试样的形貌、组织、成分等方面分析了拉拔断裂的原因。结果表明,在盘条中心处存在缩孔和疏松是造成拉拔断裂的主要原因。对连铸轻压下技术进行了优化,通过调整压下区间和压下量,提高了连铸坯的内部质量,消除了盘条中的缩孔和疏松,有效减少了盘条拉拔断裂现象。本研究为行业内相似问题的探究和解决提供了参考。

Si对缆索钢丝绳用热轧盘条组织和力学性能的影响

利用扫描电镜和能谱(EBSD)仪器对两种不同Si含量的热轧盘条的横截面和纵截面的组织形貌进行观测,并用万能试验机测试热轧盘条的拉伸性能,结果表明:随着Si含量的增加,珠光体转变的过冷度增加,热轧盘条的珠光体团尺寸和珠光体片间距减小。Si元素使Mn元素在渗碳体中偏聚,增加了渗碳体的稳定性,减小了渗碳体片层的球化倾向。Si元素使盘条横、纵截面珠光体的织构强度减弱,珠光体组织更加均匀,取向更加随机。Si元素能大幅度提升热轧盘条和成品钢丝的强度,小幅度提升塑性。低Si盘条的抗拉强度为1134 MPa,均匀伸长率为7.1%;高Si盘条的抗拉强度为1263 MPa,均匀伸长率为7.3%。低Si钢丝的抗拉强度为1937 MPa,均匀伸长率为2.2%;高Si钢丝的抗拉强度为2106 MPa,均匀伸长率为2.3%。

埋弧焊丝用H08Mn钢盘条氧化铁皮研究及其轧制工艺

H08Mn钢盘条多用于制作埋弧焊丝,其表面的氧化铁皮对拉拔前机械除鳞效果有明显影响。介绍了盘条氧化铁皮的形成机制、氧化铁皮的种类和构成;采用不同的工艺参数,包括始轧温度、精轧温度、吐丝温度和首道辊速度,轧制了H08Mn钢盘条,随后检测了盘条氧化铁皮的厚度、盘条的晶粒度和抗拉强度。结果表明:采用这样的工艺参数即880℃的精轧温度、900℃的吐丝温度和18 m/min(按5%递增)的首段辊道速度轧制的H08Mn钢盘条,其氧化铁皮厚度小于20μm且易剥落,晶粒度和抗拉强度均有利于后续拉拔加工。

提升HRB400E盘条钢筋抗震性能的工艺改进实践

针对小规格HRB400E盘条钢筋出现的抗震指标Agt值不稳定,有部分甚至出现低于国标的现象,对盘条生产工艺控制成分、控轧控冷等因素进行了分析,通过试验结果对比分析,认为抗震指标不合格主要是由钢的金相组织异常所致。为此,提出了相应的改进方案,并取得了较好的效果。

60Si2Mn弹簧钢盘条拉拔裂纹原因分析

针对60Si2Mn弹簧钢盘条在拉拔、淬火后出现的表面裂纹,通过对缺陷钢丝进行取样分析,确认为连铸坯缺陷导致,进而检查铸坯发现铸坯存在角部裂纹与之相对应。对铸坯角裂产生的原因进行分析,并提出了有效的控制措施,最终消除了铸坯角部裂纹缺陷。

6V轧机减速机输入轴端轴承损坏原因及解决措施

介绍了棒线材生产线的工艺特点,分析了螺纹钢6V轧机减速机输入轴端双列圆锥滚子轴承易损坏的原因,提出了解决措施并予以实施,成功地解决了6V轧机减速机轴承研磨的问题。

绕丝燃料棒自动外观缺陷检测系统设计

绕丝燃料棒是核反应堆中燃料组件的核心部件,燃料棒外径绕丝是燃料棒制造的关键工序,其外观质量是燃料组件十分关键的质量特性。本文以视频图像为切入点,机器视觉为技术支撑,借助深度学习建立绕丝燃料棒外观缺陷智能判别及自动定位方法。针对燃料棒表面缺陷特征,搭建高精度的图像采集系统,获取便于识别的燃料棒外观图像信息,研究检测算法能准确识别焊缝氧化色、划伤、异物、焊缝成形不良等缺陷,实现绕丝燃料棒外观缺陷的自动化检测。

小切口复位临时固定辅助股骨近端防旋髓内钉治疗股骨转子间骨折

目的探讨小切口复位临时固定辅助股骨近端防旋髓内钉(PFNA)治疗股骨转子间骨折的疗效。方法采用小切口复位临时固定辅助PFNA治疗28例股骨转子间骨折患者。记录术中出血量、手术时间、骨折复位质量、骨折愈合情况。采用Harris评分评价髋关节功能。结果患者均获得6个月随访。术后无切口感染情况发生。术中出血量95~110(100.5±8.0)ml,手术时间45~57(50.5±4.5)min。骨折复位质量:解剖复位20例,功能复位5例,复位不良3例。术后3个月Harris评分67~95(88.32±8.07)分,其中优20例、良5例、差3例,优良率25/28。26例骨折愈合,时间3~4个月,其中1例术后髋内翻畸形,无螺钉松动,应患者要求未做特殊处理;1例术后螺旋刀片向外侧切出、1例术后骨折不愈合,考虑二次行翻修手术治疗。结论小切口复位临时固定辅助PFNA治疗股骨转子间骨折,手术操作简单,创伤小,不影响PFNA操作,可辅助增强牵引床的牵引作用,疗效满意。

线材连轧生产线电磁感应补热装置及其应用

电磁感应补热装置利用金属电磁感应及涡流的原理,对轧制过程中的中间坯进行在线补热及均温处理,以满足下游轧制工艺需要。电磁感应补热装置由感应加热本体、电控系统、冷水系统及辅助设备组成,由变频电源柜、补偿谐振电容柜及感应加热器组成加热本体对坯料加热,水循环冷水系统对加热本体进行冷却降温,上位操作监控及温度闭环系统实现对整个装置的自动控制及操作监控功能。通过此装置的应用可将坯料表面温度提升100℃~130℃,头尾温度差≤50℃,使坯料整体保持均匀一致,极大改善了轧制工艺的条件,确保线材产品质量稳定、满足产品特性的要求。