In this paper, the concept and methods of statistical process control (SPC) technology are introduced, the present situations for applications of SPC technology in iron and steel enterprises of China are summarized as well as the composing elements and development directions of SPC online quality control system in the production process of iron and steel are proposed.

In 2017, the operating parameters of 7^# and 8^# blast furnaces of Baotou Steel were constantly optimized and the charging system was adjusted more in the case of using economical materials so that the reasonable gas flow distribution was realized. As a result, the long-term problems influencing the operations of blast furnace as well as the key restricted problems such as bending and damage of tuyere and the short service life of distributing device were solved so that the utilization coefficient of blast furnace in the same period was increased continually, the fuel ratio was steadily decreased and the period for trouble-free operation of blast furnace was prolonged constantly.

In this paper, the production practices of sintering with total iron ore concentrate under the condition of the self-produced iron ore concentrate of Bayan Obo as the main iron-containing raw material (85%) in Baotou Steel are elaborated. The results showed that the utilization coefficient of sintering was maintained at the original level by such measures as increasing the temperature of compound, improving the granulation effect of compound as well as adjusting the longitudinal segregation of burden distribution and the angle of the stirring machine for ensuring the gas permeability of the bed of material; the burn-up index of sintering solid was increased by 6.5 kg/t, the content of FeO in the sinter was increased and the strength of sinter was decreased by 0.15 percentage points compared with that before the practices.

The stable operation of electro-deionization (EDI) device plays a crucial role for the water needed for production of CDQ waste heat boiler. In the paper, the causes for fouling of EDI module are analyzed as well as the treatment method and preventive measures are put forward combining with the operation of EDI device in production so that the longtime run of EDI device is realized.

In the paper, the production application of 500 m² large sintering machine of Baotou Steel is summarized, analyzed and studied based on the physical properties, assimilability and fluidity of liquid phase of FMG mixed powder. The results showed that the technical index of sintering and quality index of sinter were the best when the proportion of FMG mixed powder was 20% with the current sintering process and raw material conditions of Baotou Steel; when the proportion was more than 26%, although the quality index of sinter could be guaranteed by corresponding measures, the sintering process became more difficult to control.

In this paper, the production practices on adding limonite into 265 m² sintering machine of Baotou Steel are mainly elaborated. The results showed that the grade of sinter was decreased and average grain size was poorer, while the utilization coefficient, solid fuel consumption and metallurgical properties of sinter were all improved compared with the reference period by adding 10.44%, 17.30% and 26.28% of limonite respectively in sintering so that the tumbler strength of sinter remained at the original level.

The control of w [N] in liquid steel is the important factor affecting the quality of auto sheet. In the paper, the factors affecting the w [N] in liquid steel and control measures during the smelting process with converter are discussed combining with the production process characteristics of 240 t converter of Rare Earth Steel Plate Plant of Baotou Steel. The w [N] in liquid steel supplied from converter to refing is effectively controlled below 25 × 10^-6 so that the quality of liquid steel is greatly improved.

The carbon sleeve of furnace roller is one of the important equipment in the continuous annealing production line of silicon steel, its performance and service life directly affect the quality of finished product and capacity for continuous production of the production line. In this paper, the causes for nodulation of carbon sleeve for furnace roller are summarized through analyzing it in the continuous annealing production line of silicon steel in the practical production of CSP Plant of Baotou Steel. Moreover, it is reduced by such measures as strengthening the cleaning quality in front of the furnace and reducing the carbon content in the previous process so that the purpose of stable production is achieved.

The backwater and surface water in the pump station for ponding of tailings pond were used for preparing flotation reagents for the primary flotation test. The test results showed that the backwater and surface water could be used for preparing the reverse floating collector of iron, collector of rare earth, mixed flotation collector and flotation reagents of fluorite instead of new water in productions and the effects of water quality on flotation index are not great so that the supplement of new water in productions and the production costs can be reduced.

The thermal properties of coke added different amount of ZnO and PbO are tested with the national standard method as well as the size and wall thickness distributions of pore of coke before and after test are tested, analyzed and compared. The experiments showed that the ZnO and PbO have positive catalysis on thermal properties of coke as well as they made the pore of coke greater and wall of pore of coke thinner in reaction so that the reactivity of coke is increased and the strength is decreased after reaction.

In order to understand the change rules for microstructure and properties of low alloy structural steel with controlled rolling and controlled cooling process, the Mn-B-Cr-Nb-Ti series of Q690 low alloy high strength structural steel was taken as the object of study, the change rules for structure properties with different processes are analyzed through changing the controlled rolling and controlled cooling process. The test results showed that the tensile strength, yield strength and yield ratio of the test steel were all decreased slowly, the elongation was increased and the impact energy at-20 ℃ was decreased periodically with the increase of finish cooling temperature. The microstructure was changed as the rules of ferrite, granular bainite and lath bainite as well as the effects on the properties of the material are different with the decrease of finish cooling temperature.

In the paper, the weldability of Q890D is studied with different welding experimental parameters. The reasonable welding and post-weld heat treatment processes are worked out through comparing the comprehensive mechanical properties and microscopic metallographic structure of welded joints so that their properties can meet the requirements of using product. Moreover, the deposition efficiency, formability of weld bead and change of spatter amount with different process parameters are studied, the sensitivity of welding cold cracks, mechanical properties of deposited metal for welding material and content of diffusible hydrogen for Q890D are tested.

In this paper, the microstructure and properties of high-strength steel for automobile frame BT610L hot rolled plate and hot rolled pickling plate are compared. The results showed that the grains were refined obviously, the microstructure was the dispersed distribution of a small amount of pearlite on fine ferrite matrix and the grain size was grade of 10.0, the yield strength and tensile strength were increased as well as the elongation was decreased after the pickling process; the impact tests were carried out at different temperatures, the impact toughness value of pickling plate was lower than that of hot rolled plate and their fracture morphologies were both dimple shape fracture.

In the paper, it is introduced an auto verification system for standard dynamometer is designed based on the virtual instrument technology and analyzed on the overall structure and measurement principles of the deadweight force standard machine. The modularization encapsulation of various tasks could be done by the system with its Labview development platform. Moreover, the loading/unloading weight of force standard machine as well as such functions as the collection, display, processing and management of the data tested could be realized so as to complete the automatic verification of the standard dynamometer and improve the work efficiency.

In this paper, it is introduced the technical index of NK electromagnetic ultrasonic flaw detector in 460 working zone of Steel Tube Co. of Baotou Steel, theoretical explanations of ultrasonic testing and working principles of electronic equipment for flaw detection, emphatically introduced the structure and parameter specification of electromagnetic acoustic transducer (EMAT) probe as well as the principle of waveform emission. The test results of longitudinal, transverse and delamination thickness measurement for steel tube with this equipment are stable through the actual flaw detection applications, which play a positive role in the quality control for steel tube products of the company.

In the paper, the vibrations of every measure point for generator set are analyzed with the spectral analysis and the related fault diagnosis theory through collecting the four channels time domain waveform aiming at the difficalt startup after the overhaul of TRT generator set of 5^# blast furnace in Iron-making Plant of Baotou Steel. It is found that the imbalance of couple causes the disorder of shafting so that the equipment is abnormal. The effects of imbalance of couple on shafting are effectively eliminated by introducing the online dynamic balance technology in the treatment of vibrations of generator on site.

In the paper, the harms and causes of the problem that the diesel is not unloading with the emergency braking of locomotive when the valve handle is moved to the position of emergency braking for GKD₂ and DF_7G diesel locomotives are analyzed as well as the corresponding improvement measures are established. The relevant electrical control circuit and corresponding parts are transformed so as to avoid the huge hidden dangers and harms caused by emergency braking of locomotive during normal operations while the diesel is not unloading.

In the paper, the design development and manufacturing of steel slag ladle for the mineral processing of 1.1 million tons of copper slag in Jinchuan Co. are introduced. According to the requirements of the technical agreement, the design requirements for loading the non-ferrous metallic slag are met through structural design, material selection, computer simulation and optimization of casting process plan so that the development and production of casting of cast steel slag ladle are guaranteed. As a result, the final product quality is stable and could meet the use requirements of customers.

In this article, it is introduced the basic principles and structure of the numerical controlled flame cutting machine as well as mainly analyzed the automatic height adjusting system. This control system is essentially a system of random position and composed of three feedback control loops. The inner loop is negative feedback of current cut-off, the middle loop is voltage feedback and the outer loop is position feedback. The distance between cutting torch of cutting machine and steel plate to be processed is smoothly ensured to be a constant with the system so that the cutting quality is improved and the scrap is reduced.

In the paper, it is described such problems as uneven burning in heating furnace of hot rolling, serious burning loss of oxidation, great energy consumption as well as dangerous and bad working environment of staffs are solved based on the existing first-level automation equipment and new computer technology applied in the automatic control system of heating furnace aiming at the annual output of 5.5 million tons of hot-rolled coils as well as the changing demands of steel grades, specifications and temperatures for slab with the hot rolling 2 250 mm production line. The reasonable heating of slab in heating furnace and real-time locating and tracking control are realized through the automatic combustion model and feedforward control of temperature.

A large blast furnace needs an overhaul to recover its performances within a generation of furnace life (about 10 years). During this period, several item repairs or medium repairs are needed to eliminate the defects and hidden dangers to ensure the stable and high yield of blast furnace. It is an important part of overhaul or medium repair to replace all or part of the furnace shell. The burn-through furnace shell might be with damping down for rush repair under special circumstances. In this paper, it is mainly introduced how to complete the proceeding tasks fast and efficiently as well as the technical essentials of replacing furnace shell in item repairs and medium repairs so as to achieve the standardized operations.

The protective shed at bottom floss hole of flue collector is one of the necessary safety technical measures in the construction of medium repair of converter. In this paper, such series of process as its functional orientation, design of structural style, modeling of wear-stress as well as analysis and checking calculation is discussed in detail. The purpose is to make its carrying capacity visual and quantitative as well as easy to be mastered for operators so as to create an example of standardized operations for the similar projects in future, which is of great significance for improving the operating efficiency of converter in medium repair and the level of safety protection.

In this paper, it is introduced the classification, mechanism and characteristics of film formation for polyurethane waterproof paint, analyzed such problems as precipitation, film formation, air pockets caused by bad bond with base it and the paint is too thick in the applications of polyurethane waterproof paint as well as proposed the corresponding preventive measures. Moreover, its applications in such fields as civil architecture, subway, railway bridge, water conservancy and hydropower engineering are elaborated. It is pointed out that it must be developed in the direction of green environmental protection, high performance and multifunction in the future.

The enterprise resource planning (ERP) is an advanced information management mode widely applied in modern large manufacturing enterprises. Its functions cover the whole process of productions and operations in enterprises including such as the production planning management, purchasing management, inventory management, cost control, financial management, human resources management and quality management. The cost management system as the primary subsystem of ERP project of Baotou Steel, its purposes are to establish a perfect cost collection system through such related subsystems as the production and marketing, quality, equipment, purchase and salary of ERP system. The objects of cost accounting are refined by the activity-based costing so as to realize the various targets of cost control of Baotou Steel.

The safe early warning index system is a highly integrated information analysis system. In the paper, its functions, framework and application modes are analyzed and explained. Such functions as summarizing, analyzing, early warning and issuing the information data of safe production online are realized through establishing and applying the system in safety management so that the ability of controlling accident risks and occupational hazards for enterprises are improved.