In the paper, the speed increase and strip shape optimization for producing thin strip are systematically studied aiming at such problems as low rolling speed as well as prominent shape defects of single-side wave and composite wave in the production of 0.7~1.0 mm thin strip with UCM(universal crown mill) of 2 030 mm pickling line tandem cold mill in Baotou Steel. The internal relations between speed increase and shape defects of thin strip are revealed by analyzing the characteristics of bending roll control for UCM and establishing mathematical model of roll series-strip steel coupling for strip shape control. The strategy of independent control for single-side bending roll is developed as well as the human-computer interaction interface and compensation handler of roll bending force are designed so that the risk of sudden change of strip shape is reduced by the mechanism of integral constraint. Meanwhile, the staged plan of speed increase is formulated as well as collaborative optimization of tension parameters and cooling regime is carried out. The industrial application results showed that the speed of rolling thin strip was increased by 18%, accuracy of strip shape was controlled at 8 I~20 I and hit rate of strip shape was increased to 98.5% after the optimization so that the problems of off tracking and shut-down in furnace area of subsequent process were completely solved. This study could provide the technical support for efficient and stable productions of thin strip with UCM, which is of great significances for improving the quality of such high-end products as automotive sheets.

In this paper, the causes of black spot defects on hot-dip galvanized products are mainly studied and corresponding countermeasures are put forward. It is proved that the main causes of macroscopic black spot defects are the impurities on coating surface, i.e. zinc dross defect and exposure of base steel caused by indentation through microscopic analysis and research. The amount of such defects could be effectively controlled by controlling the amount of zinc dross on galvanized plate surface, repairing top roll of cooling tower and wrapping it with cloth.

The hourly output and output per shift of pickling line tandem cold mill are influenced by such factors as varieties, specifications and production transition processes of products as well as the differences are significant. Currently, the evaluation of production efficiency is carried out by adopting the mode of converting into output or coil quantity for most mills, which is with such limitations as single evaluative dimension and insufficient objectivity of results. In the paper, the existing production specifications are divided into 16 class intervals combining with the actual productions of pickling line tandem cold mill and objectives of productions are set based on the characteristics of each class interval aiming at the problem. The quantitative evaluation system of monthly production efficiency and efficiency of each shift or group is established through the two core indicators, hourly coil quantity and rate of reaching the standard. Practices show that the multidimensional production efficiency evaluation could be realized with this system, which could provide the evaluation basis for optimizing production efficiency of shift and group as well as be with value of extensive promotion.

In this paper, it starts with the microscopic surface topography of roll. The effects and change rules of it on PC value on surface of roll are studied through processing principles and control means of such processes as roll grinding and texturing. The mathematical models of roughness and PC value, texturing times and PC value as well as such parameters as texturing gap, current and PC value are established based on the experimental data of Sarclad electro discharge texturing machine for final forming process to study their influencing rules. Finally, the optimal countermeasures for increasing PC value are selected based on actual industrial productions. After the overall process and parameters are adjusted, the PC value on surface of roll is increased and surface quality of product is improved.

The operation stability of strip steel in production line of continuous annealing directly affects the surface quality, dimensional accuracy and efficiency of production line. In order to reveal the effect laws of single side wave shape and asymmetric center wave on sensitivity to deviation, the explicit simulation model of power for single furnace roller is established to systematically evaluate the effects of such parameters as wave height, wave length and wave width on deviation of strip steel. The results showed that the larger the wave height, the greater the deviation at fixed position and the maximum sensitivity was at wave height (H) of 4~9 mm; the greater the wave length and wave width, the smaller the deviation as well as sensitivity was significantly increased when wave width was below 300 mm. These findings could provide the basis for strip shape quality control of incoming materials and improvement of deviation in continuous annealing as well as quantitative references for roll shape optimization and selecting online corrective parameters, which are helpful to improving the operation stability of unit and product quality.

In this paper, the narrow lap welding process and evaluation method of weld quality for over 1 180 MPa grade cold-rolled high-strength steel are elaborated. The types and causes of weld defects are analyzed and investigated through weld test so that the parameter adjustment methods for eliminating weld defects and improving weld quality are determined. The weld joints are qualified according to the feedback of welding monitoring system, the results of cupping test for weld joints are qualified and the fracture not at weld joint in tensile test could meet the requirement. The results proved that the weld joints of the material were qualified with the combination of welding process parameters of low welding current, low welding speed and high welding pressure.

In the paper, such problems as improper shearing parameters adjustment, nonstandard replacement process of shear blades, jam of scrap edge and poor running of belt in the shearing process with circle shear of galvanizing unit in Cold Rolled Rare Earth Steel Plate Plant of Baotou Steel are mainly elaborated, which cause the normal edge trimming of production line to be incapable as required or poor edge trimming so that the improvement of first pass yield and normal delivery within delivery cycle of products with main production line are affected. In order to improve the edge trimming quality of circle shear as well as ensure continuous stable and high production, the experiment is carried out to ensure stable operations and edge trimming quality of shearing process with circle shear.

The 310 zed beam is mainly used for manufacturing the automotive frame at the bottom of railway freight car and oil tank truck, so the requirements of its corrosion resistance, strength and surface quality are extremely strict as well as the surface defects could directly affect its service life. Its main surface defects include local dent at shoulder, bracing wire and roll marks. The amount of main defects is significantly decreased by taking such measures as optimizing roll pass design of UR (universal rolling) mill as well as improving guide fittings of BD2 (second breakdown) mill and CCS (compact cartridge stand) mill so that the quality of 310 zed beam is improved, which could meet the development demands of railway heavy haul traffic.

In the paper, the effects of composition adjustment on mechanical properties and production costs of steel are systematically studied through optimizing the composition control range of such strengthening elements as Mn, Ti and N as well as adopting staged industrial tests and regulating methods of closed-loop characteristics aiming at such problems as higher strength of raw materials in hot rolling, more roll consumption of pickling line tandem cold mill, easy slipping of rolling mill, large fluctuation of yield strength and higher costs in the production of S350GD+ZAM and S450GD+ZAM Zn-Al-Mg structural steels. The results showed that the mechanical properties of both products could meet standard requirements after optimization, rate of reaching the standard for properties of S350GD+ZAM was increased from 96.4% to 98.7%, allowance of yield strength for S450GD+ZAM was sufficient and its rate of reaching the standard was 98.2%; accumulated cost reduction of them in 2024 was RMB 749,320 Yuan so that production bottleneck was effectively broken as well as cost decreasing and benefit increasing were realized, which could provide reproducible industrial technical path for low-cost and stable productions of structural steel with Zn-Al-Mg coating.

In order to expand the product type mix of CSP production line and break the technical bottleneck of producing microalloyed pipeline steel with compact process of strip steel, the industrial trial production is carried out based on Q355B bridge mode with smelting of KR (kambara reactor)-BOF (basic oxygen furnace)-LF (ladle furnace)-CC (continuous casting) and low C-Mn-Nb-Ti microalloying system by taking the pipeline steel L415M as the object in this paper. The results showed that the performances of sample with the specification of 9.75 mm could meet the requirements as well as there was performance fluctuation at head and in the direction of 45° for sample with the specification of 7.75 mm. Due to the limit of equipment conditions, the grain is coarser, strength is lower and yield ratio is higher for the product. The stability of product with thin specification could be improved by optimizing the composition and process, which could provide the technical support for large scale production of pipeline steel with the CSP production line.

Tandem cold mill is the key equipment for high speed production of cold rolled plate and strip, the negative values of forward slip are prone to occur in production process of cold rolled hard substrate. In this paper, the problem is studied by exploring the formation mechanisms of forward slip backward and influence relations of process parameters as well as the improvement strategies are proposed based on the influencing rules of exit thickness, tension at entry and exit and friction coefficients. The experiment proved that negative values of forward slip could be effectively improved with the strategies so that the mill is forced to return to normal state.

A series of low temperature impact tests are required for the welding experiment of BT620QL6 low temperature crack arrest steel plate so that multiple times of preparation and processing for impact samples of test piece for welding are needed. The slotting positions of welded samples cannot be ensured to be precise in welding heat affected zone so that the welding impact test results could be influenced and fluctuations of series of low temperature impact absorbing energy are greater with traditional processing method of impact sample. In the paper, the slotting positions of impact sample notch of welded plate are determined, uniformity and continuity of machining dimension precision for samples in the same group are ensured, sensitivity of welded impact samples on sampling positions is eliminated as well as preparation efficiency of sample for welded plate is improved through improving the processing method of sample for welded plate combining with the standard requirements of test sample for welded plate. The test results showed that the stability of data for impact property of BT620QL6 welded plates was improved with the improved processing method of impact sample.

Belt wrapper is the key equipment for pickling line tandem cold mill of cold rolling mill, its stable operations directly cause successful threading and good coiling quality of strip steel. As the key link in production, the fault of threading with belt wrapper is one of the main causes for shutting down of production line. In the paper, it is deeply analyzed the working principles and fault causes of belt wrapper as well as systematically proposed corresponding troubleshooting procedures and processing schemes based on its principles and common faults, which are aimed at providing effective technical guidance for equipment maintenance and rapid fault diagnosis on site.

In the paper, it is elaborated the problem that chamfer at edge of backup roll is prone to gradually wear to be disappeared during its service and grinding processes more than once on site. In early stage, the manual grinding is adopted to chamfer at edge of backup roll with angle grinder so that the processing efficiency is low, human cost is high as well as accuracy to size and shape of chamfer is difficult to be guaranteed. If they are not repaired in time, there will be crushing stress between backup roll in online use and edge of intermediate roll so that cracks are easily induced and extended further. In late stage, a type of automatic grinding equipment for chamfer at edge of backup roll is designed and developed so that the efficient and high-precision grinding of chamfer could be realized. The labour intensity of operating personnel could be reduced to guarantee operation safety and chamfer could be ensured to be uniform so that dimensional precision could meet the operating requirements.

In the paper, the technical reform scheme of mandatory lubrication oil return with compressed air purging is proposed by taking original gas-liquid balanced accumulator of the system as the access point aiming at such problems as large residual quantity and more loss of lubrication oil as well as serious resource waste and lubrication oil contamination in the environment at the scene for centralized thin oil lubrication system of roll bearing for five-stand six-high tandem cold mill of Cold Rolled Rare Earth Steel Plate Plant of Baotou Steel in the process of changing roll. The recycle rate of residual lubrication oil for bearing housing could approximate 100%, purchase costs of oil products and waste oil disposal costs could be significantly reduced, working environment of roll assembly area could be improved as well as equipment maintenance efficiency and cyclic utilization rate of resources could be increased with this technical scheme, which could provide mature, feasible technical references and engineering practice examples for lubrication oil consumption control of centralized lubrication system of large bearing of the same kind as well as energy saving and cost reducing in cold rolling field of metallurgical industry.

In the face of a bulk of vibration signal data of gear system, fault features have been difficult to be accurately extracted and efficient fault classification could not be completed with conventional signal analysis methods. In the paper, a method of reconstruction from one-dimensional sample data to two-dimensional data is proposed aiming at the problems and the reconstructed two-dimensional data are input into the convolutional neural network (CNN) for fault feature extraction and fault classification to solve the problem of end-to-end fault diagnosis. Eventually, the high accuracy rate of 99.7% is achieved. The experimental results showed that the method of reconstructing two-dimensional data and inputting them into the CNN was suitable for fault diagnosis of gear system.

Automatic surface quality tester is the system for online automatic inspection of surface quality of strip steel, the manual inspection is replaced with high-precision camera and computer image algorithm to conduct automatic inspection of surface defects so that it plays an irreplaceable role with high efficiency and sensitivity in production line of high-end plates. During operations, the surface quality inspection of products could be interrupted by system faults and then rhythm of production with galvanizing unit and trace of product quality data in later period could be affected. In the paper, the related effective measures are introduced and analyzed so that the problem of system stability is solved. Furthermore, a set of simple, convenient and rapid judgment method for fault points are summarized, which could be as references for applications of intelligent measuring instrument.

In the paper, an implementation method of intelligent safety management system is proposed by taking the microservices architecture as support and data driving as the core combining with the national safety production regulations and construction requirements with dual prevention mechanism aiming at such problems as information isolated island, response lag and lack of closed-loop management in traditional safety management of steel enterprises. Such key competencies as dynamic identification of risks, whole-process treatment of hidden dangers, whole-process supervision of high-risk operations, integrated access of interested parties and quantitative incentives of safe behaviors are realized through unifying data standard, reconstructing business processes, integrating interfaces of multi-source system and relying on enabling of mobile terminal and closed-loop control mechanism. The actual deployment in Baotou Steel showed that the transformation of safety management from "passive response" to "active prevention" and from "experience judgment" to "data-driven decision making" was effectively promoted with the system, which could provide the feasible technical solutions and implementation paradigm for establishing digital safety system in flow type heavy industrial enterprises.

With the rapid development of economy in our country, the demand of cold rolled steel plate products is increased continuously and wastewater containing thin oil has become one of the main types of wastewater in iron and steel enterprises. It is crucial for reaching the standard of environmental protection and recycle of water resource in enterprises to efficiently and stably treat the wastewater containing thin oil. In the paper, the removal effect and operating characteristics of chemical oxygen demand (COD) in each process section are systematically analyzed through the data of over 700 water quality tests in one year based on the combination process of neutralization-coagulation flocculation-air flotation-bioactive sludge by taking the treatment system of wastewater containing thin oil in Cold Rolled Rare Earth Steel Plate Plant of Baotou Steel as research object. The results showed that the average removal rate of COD in pretreatment unit of flocculation-air flotation could reach 75.24% so that degradable organics could be efficiently removed; recalcitrant wastewater was further degraded with biological system and the COD of final effluent was stably lower than 70 mg/L. The study could provide data supports and practical references for stable operations, process optimization as well as operation and maintenance control of system of wastewater containing thin oil in cold rolling.

The industry chain of large iron and steel metallurgical enterprises covers the whole process of mining, beneficiation, ironmaking, steelmaking, rolling and forming as well as there are multiple high-risk hidden dangers such as coal gas leakage, high temperature melting and toxic and harmful corrosion in every production link, so the safety equipment and facilities are the core hardware support for safety production in the enterprises. In the paper, the suitable optimization measures are put forward from such dimensionalities as management consciousness, system construction and full life cycle management based on the process characteristics of iron and steel production as well as analyzing the current situations and core problems in the management of safety equipment and facilities in this type of enterprises. It is aimed at perfecting their management system of safety equipment and facilities so as to provide practical references for safety production management in similar domestic enterprises.

The information barriers could be broken through and the target of data value conversion could be ensured to be realized with data sharing and exchange platform, important product of the digital age. Due to this platform covers several links of data processing including collection, transmission, storage and sharing, it greatly supports cross-department and cross-disciplinary collaborations. The open features of platform are relatively prominent and diverse security risks are faced in operations so that smooth operations of the platform are influenced. In order to maintain normal operations of the platform and ensure to realize its functions, such safe protection measures as strengthening the service supply chain management of platform, perfecting data security management system and strengthening applications of protection technologies are proposed based on full process safe protection of platform, which are hoped to strengthen the safety defense line for operations of platform to maintain the security in each link of data transmission, sharing and exchange.

In the paper, the design, research and development and performance verification of high-efficiency intelligent dry-wet cooling tower are carried out by taking the working conditions of high temperature, heavy dust and high load in the whole process of iron and steel as application scenarios as well as combining with plate-fin demisting heat exchange and intelligent collaborative control technology aiming at the pain points of high energy consumption and water consumption, poor adaptability of working conditions and high operation and maintenance costs for cooling system of ferrous metallurgy. The results showed that the automatic precise switch of dry model and wet model could be realized with the cooling tower, which was adapted to the cooling requirements of the whole process of iron and steel; annual average water-saving percentage could reach 22.3%; zero mist operation could be realized at the working condition of -10 ℃ and relative humidity of 70% so that such industrial problems as scaling, abrasion, drifting mist and higher energy consumption of traditional cooling tower could be effectively solved.