In the article, it is discussed the effects of drying time, prepared sizes, preparation time, stirring means and storage time of samples on measurement results of caking index which are not specified in the national standard GB/T 5447—2014. Such two types of frequently-used bitumite, coking coal and gas coal are selected for experimental study. The study results showed that the effects of drying time, particle size and preparation time of samples on measurement results of G value were the most significant, the effects of analysis link and storage time of samples on measurement results of G value took second place, while the effects of stirring means on measurement results of G value were minimum. The specified control conditions of related influencing factors are given through experiments so as to achieve the goal of improving the accuracy of measurement results for caking index of bitumite.

In this paper, it is introduced the determination of oxygen content in lanthanum-iron alloy with the pulse melting-infrared absorption method. The preparation method and optimal analysis conditions are determined by studying the preparation methods of sample as well as analyzing the effects of power, weighing sample and flux on determination results of oxygen content. The standard deviation is less than 5% and recovery rate is 95%~105% for this method, so it is with good precision and accuracy.

In this paper, two types of online as-heat-treated pearlite rails are tempered. The optimal tempering process of two types of high-strength heat-treated rail is obtained based on the changes of mechanical properties and microstructure for the rails under different tempering temperatures. The results showed that the comprehensive mechanical properties of rail could be improved by low temperature tempering within the range of 200~350 ℃. With the increase of tempering temperature, residual stress of rail web tends to be decreased. The residual stresses of rail web for the two types of rail are 45 MPa and 32 MPa respectively with tempering at 350 ℃, which are decreased by 63.4% and 80.6% compared with those before tempering. The hardness, toughness and plasticity of tempered rail are improved with the increase of tempering temperature. The hardness is significantly increased with the improvement of plasticity and toughness. The tread hardness (HBW) of rail is increased by 13 and 8 respectively with tempering at 350 ℃ as well as the tempered rail is still with typical perlite structrure.

With the incremental production of small size products, coil shape control gradually becomes the key link to restrict quality and benefits. The defective coil shape not only affects operation rate and economic and technical indexes of high speed wire rod production, but also causes such problem as there are troubles in the process of using wire for downstream users so that the efficiency of downstream processing is affected. In this paper, it is analyzed some factors affecting the spinning state of wire rod in high speed wire rod production line, briefly elaborated several cases of defective coil shape in production process, analyzed causes of problems and proposed solutions so as to improve the production efficiency and quality of product. The regular coil shape could ensure smooth wire and reduce rate of fracture of wire for drawing of users so that the quality improvement in the whole process is realized.

The studies on hardenability and heat treatment test of steel tube for trenchless drill pipe are carried out combining with its service condition requirements and main failure modes in the paper. The experimental results showed that the depth of hardening layer for obtaining minimum 50% martensite was 11 mm and that for obtaining minimum 95% martensite was 7 mm for the seamless steel tube for trenchless drill pipe containing rare earth, which was with good hardenability; the optimal recommended heat treating regime was obtained after the heat treatment test with adjusting tempering temperature.

The effective volume of 7^# blast furnace of Baotou Steel is 4 150 m³. On October 23rd, 2022, it was blown down for gunning of lining and remolding inner profile. In the blowing down, the method of dropping stockline by spraying water was adopted and the stockline was dropped to a position below center line of tuyere. The methods of reducing the basicity of furnace slag ahead of time and increasing furnace temperature were taken to increase wall temperature, the match of air and oxygen quantities and assessment method of depth of stockline different from the past as well as the method of spraying water, that is, monitoring the mean value and difference value trend of four points of top temperature to control the water quantity were adopted. After taking the above measures, stockline could be dropped safely and rapidly.

In the production technology of continuous casting, oriented silicon steel, as a type of “soft steel” in the traditional sense, shows unique physical properties. Its thermal conductivity is relatively poorer, liquid thermal conductivity is approximately 27% lower than that of ordinary carbon steel so that it shows significant weak thermal conductivity. This property makes it easy to be deformed in high temperature environment. Consequently, there are often such surface defects as liquid level fluctuation of crystallizer, bulge and dimple of ingot blank as well as such internal quality issues as center segregation, center porosity and cracks during the continuous pouring production process. These issues directly impact the number of continuous pouring heats. In order to solve these problems, it becomes the key strategy for increasing the number of continuous pouring heats to design and implement reasonable cooling regime and casting speed.

In this paper, the measurement methods of gauge, diagonal and horizontal bending of main beam for metallurgy crane are mainly studied. Traditional measurement methods for crane with such tools as steel wire and ruler are with such disadvantages as low efficiency, poor accuracy, strict conditions and high safety risk. In order to finish the measurement work of metallurgy crane accurately and efficiently, several methods for measuring gauge, horizontal bending and diagonal of metallurgy crane using instruments and tools are studied as well as the traditional measurement methods of crane are improved and innovated. Practices show that the efficiency of measuring metallurgy crane is greatly improved with these measures.

With the rapid development of artificial intelligence, automatic driving technology and intelligence of mining, unmanned intelligent vehicles in mines have gradually become the important tool for improving operation efficiency in mines, reducing accident incidence and saving costs. In this paper, the key technologies, functions and challenges faced of unmanned intelligent vehicles in mines are systematically analyzed. First, the application background of driverless technology in mine environment is discussed as well as such key technologies as perception, decision making, control and communication it needs in mining operations are analyzed. Second, the core functions of unmanned intelligent vehicles in mines including auto drive and path planning, collaborative operations, safety and exception handling are proposed. Finally, the technical challenges faced by unmanned intelligent vehicles under the working conditions of complex geographical environment, severe weather and high load are analyzed as well as the solutions are proposed and development trend of unmanned intelligent vehicles in the future is prospected. This paper is aimed to provide the theoretical supports and technical references for research and applications of unmanned intelligent vehicles in mines.

The 590CL wheel steel is formed by spinning and stamping technologies to be made into automobile spoke. There is cracking in the process of stamping air hole. The cracking position is determined to be between the air hole on outer edge of spoke and shear end as well as fracture origin is at the air hole end of wheel steel, which is about the central part of plate thickness through macroscopic observation of cracked wheel steel as well as such comprehensive analysis as scanning electron microscope and metallographic examination; the zone of segregation in the core of wheel steel with inclusions those are mainly C and Nb in shape of dot string could all hinder normal deformation of ferrite in pre-forming process so that the fluidity of metal is inconsistent. As a result, the work hardening is generated and stress concentration in segregation in the core induces cracks, then stress is released through punching so that cracking is caused. It is suggested to adjust the composition to ensure appropriate proportions of niobium and carbon as well as optimize processes of steelmaking, continuous casting and rolling in the future production and processing processes.