In the paper, the series of tempering tests of quenched 75 kg/m bainite rail in laboratory are introduced as well as the mechanical properties and microstructure of the rails with different tempering processes are compared and analyzed. The results showed that the optimum mechanical properties of test rails could be achieved with 320 ℃ heat preservation for 48 h, which could satisfy the operating requirements of rail for heavy haul railway.

In the paper, it is introduced the exploratory study on low temperature reagent is carried out in view of the mineral characteristics and climatic conditions of Bayan Obo Iron Mine. Compared with the original flotation reagent, the flotation temperature can reduce to about 30 ℃ with the new low temperature reagent, the grade of iron concentrate increases by 0.22 percentage points and the recovery rate increases by 1.26 percentage points.

In the paper, the purpose of reducing heat consumption is achieved on the premise of ensuring the stable coke quality by adjusting the lateral temperature as well as the temperatures of coke oven end and top space in the heating schedule of coke oven aiming at the problem of higher heat consumption of coking in the heating schedule of 7 m large capacity coke oven.

In this paper, the influencing factors of coking coal in hot performance test are analyzed and they are mainly reflected in the process of smelting coke with coking coal, sample preparation method of coke and the hot performance test process of coke. The effects of the process of smelting coke with coking coal on hot performance of coke are mainly reflected in type of test coke oven, temperature control program, coal capacity, density of coal charge and mode of quenching coke. Sample preparation is a key operation in the hot performance test for smelted coke and its influence on test values is significantly. With other conditions the same, the stability of test values for hot performance test of coke with pure handmade sample is the best, but the values are higher. The effects of test process on hot performance of coke are mainly reflected in the number of sample, flat-temperature zone of oven, thermocouple of temperature control, reactant gas and standard screen.

The main factors affecting quality of modified pitch are determined by analyzing the factors affecting qualification rate of modified pitch. They are low content of toluene insoluble in crude tar, flash oil flows backwards, poor cooling effect of flash oil and low degree of polycondensation of modified pitch in the reactor. The qualification rate of modified pitch is significantly improved by such measures as reducing rotate speed of centrifuges, transforming gas collecting tube of flash oil, absorption tube of flue gas and position of cooler of flash oil, increasing the softening point of mid-temperature pitch and temperature of reactor.

The blast temperature of hot blast stove of 3^# blast furnace of Baotou Steel is seriously insufficient, so the checker brick needs be replaced when cooling hot blast stove. The job is summarized in this paper. The preparatory work before cooling hot blast stove is sufficient, installation of equipment for cooling hot blast stove is smooth and process selection is correct, the whole cooling process lasts for 38 days. As a result, it is successful since the temperature of 1^# hot blast stove decreases from 800 ℃ to below 50 ℃, which provides references and theoretical basis for cooling hot blast stove of silica brick of Baotou Steel in the future.

In this paper, it is mainly elaborated the experimental study of W ore fines with the condition of sintering iron charge of Baotou Steel. The results showed that it was beneficial for increasing grade of sinter, reducing content of harmful ingredients, P and Al₂O₃, increasing sinter product ratio, reducing fuel consumption and increasing drum strength of sinter so that its reducibility is improved by replacing F ore fines with W ore fines. However, because the particle size of W ore fines is larger than that of F ore fines, the vertical sintering speed will increase and the sintering rate will decrease. The moisture of mixture needs to be reduced to stabilize the vertical sintering speed.

In the paper, the causes that load of 8^# and 9^# boilers of Power Supply General Plant of Baotou Steel decreases year by year with the co-combustion of coke oven gas are analyzed. It is judged to be the impurities in coke oven gas. Finally, the solutions are put forward by studying the influences of co-combustion of coke oven gas on boiler.

In the paper, it is introduced the ultra fast cooling control system suitable for hot-rolled dual phase steel is developed based on the CSP production line with short process and its industrial applications are realized. The results showed that the control of water supply pressure was realized with the pressure closed-loop of power pump and fuzzy PID control of relief valve; the control of flow for header was realized with the fuzzy control of control valve; the tracking of position of strip steel was realized with the accumulation of product of actual speed of strip steel and scan period of program. The cooling rate of hot-rolled strip steel with thickness of 6.0 mm was 190~210 ℃/s, the cooling rate of hot-rolled strip steel with thickness of 11.0 mm was 100~120 ℃/s, the medium temperature was controlled at (670±10)℃ and the coiling temperature was controlled at target value ± 30 ℃, which well met the product requirements.

In order to improve product quality, the steel-making process of 70 high carbon steel is optimized and improved by Baotou Steel. The results showed that the slab quality was significantly improved, levels of centre burst, center porosity and defect of non-metallic inclusions were all not over grade 0.5, proportion of columnar crystal was smaller and its texture was dense; the enrichment and segregation of carbon element in the center of casting blank of 70 steel were effectively reduced, central carbon segregation index decreased from 1.10 to 1.03 and no large-grained non-metallic inclusions were found in casting blank after the process optimization; the drawing fracture of wire rod was effectively suppressed and drawing property was significantly improved after the improvement.

In this paper, the cause for the crack at corner of casting blank is introduced. It is found out that the boron nitride precipitates along grain boundary and weakens the original austenite grain boundary as well as the crack is produced along grain boundary with the subsequent effects of straightening force by analyzing with such detecting techniques as metallographic examination and scanning electron microscopy.

The metallographic structure and mechanical properties of A333 Gr. 6 seamless steel tube at low temperature with such two heat treatment processes as "normalizing + tempering" and "normalizing" are studied and analyzed through comparative experiments. The experimental results showed that the A333 Gr. 6 seamless steel tube at low temperature with normalizing could meet the standard requirements so that the manufacturing costs were reduced and competitiveness of enterprise was enhanced.

In this paper, the mechanical properties of U75V heat treated rail were tested in accordance with the Russian standard ГОСТ Р 51685-2013. The results showed that the tensile property of rail after tempering could meet requirements of the Russian standard ОТ350HH for low temperature resistant rail and impact performance is lower than standard requirements. This is mainly because the chemical composition and heat treatment process of steel are different.

In order to improve the performances of low-alloy high-strength hot rolled H beam product of Baotou Steel, reduce its production costs, enhance its product competitiveness as well as improve the economic benefits and production efficiency of enterprise, its characteristics such as the production technology, microstructure and performance are analyzed in this paper. The cost of alloy in steel is reduced and product profit is increased through the design idea of replacing vanadium with niobium and reducing Mn so that its mechanical properties are ensured to meet product standards.

In the paper, the causes of cracks are analyzed and measures for reducing crack rate are put forward aiming at the longitudinal cracks along web on the surface of finished product, the low cost Q355B containing Ti, produced with beam blank by Baotou Steel. The results showed that the cracks were caused by small cracks on continuous casting billet, which grew and formed in rolling process, the longitudinal cracks could be significantly reduced and crack rate of finished product could be reduced to less than 3% by the reasonable matching of casting speed and tundish temperature.

The round steel for sucker rod is with high strength and corrosion resistance. The 30CrMoARE round steel with rare earth for sucker rod is successfully developed through adopting ladle furnace to feed rare earth wire, effectively controlling the content of such impurity elements as S and P as well as reasonably controlling rolling technology. The inclusions of product≤grade 1, yield strength≥1 027 MPa, tensile strength≥1 087 MPa, elongation≥14% and impact toughness≥144 J so that all the performance indexes could meet user requirements.

It is proposed to discriminate working conditions of rolling bearing with Hilbert envelope demodulation in consideration of the fault diagnosis involving such disciplines as machinery, signal processing, advanced mathematics and vibration as well as combining with the working conditions of field equipment and specific circumstances of spot check personnel. The practicability and effectiveness of the method in fault diagnosis for rolling bearing of speed increasing machine for rolling mill are verified through analyzing field data with the intelligent point detector encapsulated with Hilbert envelope demodulation circuit.

A considerable number of liability accidents in the railway transportation of metallurgy enterprises are due to the interruption of diesel locomotive driver's lookout and operation without obeying the regulations resulting in slipping of locomotive. In the paper, it is introduced the vigilance device suitable for installation and use of diesel locomotive to prevent slipping and interruption of lookout is developed by analyzing and researching the control circuit and operating characteristics of GK0 diesel locomotive as well as the expected effects are achieved through tests and applications.

The vibration signal of rolling bearing on the driving side of dust-removing fan of Iron-making Plant is with such characteristics as strong nonlinearity and modulation due to it is in service in the harsh environment of high temperature, high humidity and much dust as well as the complex working condition of strong background noise so that its fault character frequency is difficult to be extracted and identified. With the variational mode decomposition (VMD) and maximum correlated kurtosis deconvolution (MCKD), the noise reduction and extraction of fault character frequency for vibration signal of rolling bearing for dust-removing fan are realized as well as the fault identification is completed by envelope demodulation.

As the important data of consumption and output in production process of iron and steel, energy data affects the input and income in production process of iron and steel enterprises as well as the reasonable distribution and supply, optimal consumption and minimum emission of these dynamic medium can be achieved with it. In view of the shortcomings of existing energy system, the more advanced Nari system is used to upgrade and build an intelligent energy measurement system to meet the current manufacture requirements.

The environment of production site in industrial enterprises is complex and dangerous, so operating personnel is required to wear labour protection appliance to ensure to be protected against personal injury in the operation process. In this paper, a detection system for personnel to wear labour protection appliance based on deep learning is designed to detect such objects as the personnel, safety helmet and CO alarm apparatus in the image as well as normalize the inference algorithm of wearing based on the deep learning object detection model so that the automatic identification of wearing labor protection appliance for operating personnel is realized and the accuracy rate is over 90%.

The structure and working principle of rotary oil feeder for coiler are introduced, the causes for its oil leakage are analyzed as well as its pipeline is optimized aiming at the problem of oil leakage. The practices prove that the problem of oil leakage of rotary oil feeder for coiler is effectively solved with optimization.

The 2 250 mm hot rolling production line of Inner Mongolia Baotou Steel Metal Manufacturing Co., Ltd. is one of the last production lines put into production in China at present. The new equipment status, especially the accuracy of rolling mill, is the key index for accuracy of device we urgently need to know currently. With the R & D of digital platform for stiffness of hot finishing mill stand of Baotou Steel, the timely and rapid data collection is finished in the short time of shut-down for changing finishing roll, fault handling and short-time overhaul as well as the data is integrated into platform to know virtual condition of rolling mill in time so that the accuracy of rolling mill is improved effectively in real time as well as continuously stabilized and improved.

The technology and equipment are improved, cleaning difficulty is reduced and cleaning efficiency is increased from the perspective of realizing on-line cleaning of mist catcher based on analyzing the factors affecting resistance of mist catcher in production process of desulfurization system.

In the paper, the causes for blocking of regenerator for heating furnace of 1^# production line of Long Products Plant of Baotou Steel are analyzed as well as the solutions are put forward according to the working principle of regenerative heating furnace and characteristics of regenerator, with which the replacement cycle of regenerator is effectively prolonged, maintenance costs are reduced, production efficiency is improved and some economic benefits are obtained.

The monitoring of deep horizontal displacement is the key project for field monitoring of foundation pit engineering. In this paper, the method more beneficial to safety of foundation pit engineering is found out through technical analysis on monitoring data of deep horizontal displacement in the foundation pit monitoring project of Baotou three-dimensional comprehensive traffic hub, comparative analysis of displacement and time curves based on field measurement as well as based on embedded positions of inclinometer, selected support systems and different construction procedures of support structure, hoping to be beneficial to future engineering practices.