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.

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.

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.

Finite Element Simulation of Rod and Wire Continuous Rolling

This paper discusses the application of several techniques involved in the development of the 3D finite element (FE) models of rod and wire continuous rolling process.The FE models are implemented into the FE-program MSC.Marc and used to investigate the thermal and mechanical behavior of billet during the rolling process.All nonlinear equations included in the models are solved by the static and dynamic procedures,respectively.Data transfer technique is proposed to keep the continuity of simulation results.And the computational time of static procedure is significantly reduced by using a rigid pushing body.In all models,the constant time step method and the auto time step method are respectively used to define time step for the solution of equations.Simulation results of the models with different time step methods are compared.And comparison between calculated values and measured ones of the temperature at the surface of billet shows the validity of the FE models.

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.