With the development of digital and intelligent technologies in each field, they are widely applied due to the high efficiency and accuracy they brought. The digital and intelligent technologies for detection and routing inspection of industrial buildings (structures) are increasingly developed. In this paper, the important roles of intelligent detection technologies in safe operations of structure for industrial buildings (structures) are compared and explained through the specific analysis on applications of such three common intelligent detection technologies in detection of industrial buildings (structures) as unmanned aerial vehicle platform technology, digital image recognition technology and network technology of intelligent sensor for Internet of things.

The packaging capability of Φ159 mm PQF hot continuous rolling steel pipe unit of Baotou Steel is unmatched with previous process due to its inadequate design and new packaging standard of steel tube is implemented. As a result, the steel tubes are piled up before packaging process so that the whole production line is restricted to reach target output and efficiency. In the paper, the causes restricting packaging capability are found through causal chain analysis and functional modeling with the theory of inventive problem solving (TRIZ). Such equipment as packer and storage rack of steel belt are designed and manufactured so that the bottleneck of packaging process capability is broken through and capacity balance between processes of the whole production line is realized. The yield and packaging quality of seamless tube are greatly improved through the successful reconstruction of packaging system.

In the paper, the chromite as well as external phlogopite and ferrodolomite are analyzed with such means as the point analysis with EPMA(electron probe micro-analyzer), map scanning and correlation analysis from the perspective of geochemistry. It is found from the analysis results that three annuluses can be seen inside and out of chromite, the contents of Al, Mn and Zn in the center are higher than those in outer ring as well as content of Fe in outermost ring is high, that is, the contents of Mn, Al and Zn are gradually decreased as well as content of Fe is gradually increased inside and out of the chromite. This indicates that the magnesium aluminate spinel should be formed firstly in this region, then it is replaced by fluorine-rich magma to chromite in later period, the fluorine-containing and silica-containing magma upwells into carbonatite dykes along channel as well as it is condensed into fluorine-containing phlogopite at the same time. The conclusion consistent with the above could be obtained with the Pearson correlation analysis, that is, there are negative correlations between FeO and Cr₂O₃, MnO, ZnO and Al₂O₃, which shows that there is isomorphic substitution among them.

The flotation process is the main method for removing impurity element fluorine in magnetic iron ore of Bayan Obo. The indicators and productivity of flotation operation can be effectively improved by reasonably selecting process flow of flotation. The existing flotation process is analyzed aiming at such problems as high iron grade and low productivity of flotation tailings as well as high consumption of reagent for flotation operation of magnetic iron ore of Bayan Obo. It is found that the gap between iron grades of foam in the first and second stages of rougher flotation is great, the iron grade of foam in the first stage is lower than that of flotation tailings, and then it is mixed with foam in the second stage to enter operation of scavenging so that the iron grade of flotation tailings is high and productivity of flotation is low. The foam in the first stage of roughing for flotation is directly with discarding tailings and conditions of flotation operation are reoptimized. In actual production, the iron grade of flotation tailings is decreased by 5.34 percentage points and productivity of flotation concentrate is increased by 6.16 percentage points after improving the process.

In order to relieve the environmental pressure caused by a large amount of waste in the process of smelting rare earth, the experimental study on beneficiation of high grade rare earth ore concentrate of Bayan Obo is carried out. The sodium silicate is as inhibitor, reagent of hydroximic acid is as collecting agent and 2^# oil is as foaming agent as well as the closed circuit experiment process of “one time of rougher flotation and four times of concentrations” is adopted in the flotation test of rare earth. As a result, the rare earth ore concentrate with grade of 62.79% and recovery rate of 84.73% is obtained, which lays a good foundation of raw material for subsequent clean productions.

The intellectual features of beneficiation equipment become increasingly prominent and efficient upgrading of intelligent beneficiation equipment technology is one of the effective ways to improve beneficiation efficiency. In this paper, it is systematically introduced the development process of photoelectric intelligent sorting technology in the field of beneficiation and its application progress in multi ore sorting. Moreover, it is introduced and analyzed the working principles and technical performances of XRT intelligent sorting machine. Finally, it is introduced the experimental study of pre-separation for iron bearing rock of an iron ore with photoelectric intelligent sorter. The results showed that the rough concentrate with the iron grade of 25.13% and recovery rate of iron of 67.98% could be obtained by discarding the tailings with the iron grade of 9.53% and productive rate of 55.39% under the condition of the raw ore with the particle size of 10~100 mm and iron grade of 16.49% so that the expected indicators could be achieved, which provides scie.pngic basis for the resource utilization of iron bearing rock and the further popularization and applications of the equipment.

The basicity is an important chemical index of blast furnace slag and it plays a decisive role in the trouble-free operations of blast furnace ironmaking. In this paper, the effects of basicity on rheological behavior of blast furnace slag of Baotou Steel are studied under N₂ atmosphere with slag specimen prepared by pure chemical reagent based on the slag of 4^# blast furnace of Baotou Steel. Moreover, the rules of melting behavior for blast furnace slag with basicity of slag changes are analyzed. The results showed that the melting temperature, viscosity and activation energy of viscous fluid flow of blast furnace slag of Baotou Steel were first decreased and then increased as well as fluidity and thermal stability of slag became better first and then worse when basicity of slag was increased from 1.00 to 1.30. With the basicity of slag increases, the softening temperature, hemispherical temperature and flow temperature of blast furnace slag tend to be increased, which are conducive to moving down of softening zone of blast furnace in the process of ironmaking and promoting development of indirect reduction in blast furnace. It is suggested that the basicity of blast furnace slag of Baotou Steel should be controlled within the range of 1.10~1.20 through overall consideration of the effect laws of basicity of slag on viscous and melting behaviors of blast furnace slag of Baotou Steel.

The effects of double calcium treatment mode (Ca treatment-RH-Ca treatment) and single calcium treatment mode (RH-Ca treatment) on removing inclusions are studied with the process route of BOF-LF-RH-CC. The study results showed that the size and number of inclusions in molten steel with single calcium treatment mode when RH left were smaller than those with double calcium treatment mode so that single calcium treatment mode was better than double calcium treatment mode.

The methods of manual dynamic regulation of bottom blowing of converter with steel grade of smelting and dynamic maintenance of furnace profile are proposed aiming at such problems as low gas supply intensity of bottom blowing, short service life of breathable element for bottom blowing and lower combined blowing rate for 150 t top bottom combined blowing converter in Steel-making Plant. Different gas supply intensity models are established and gas supply intensity of bottom blowing is optimized based on the requirements for end point carbon content of steel grade in actual production. As a result, the dynamic control of gas supply intensity of bottom blowing for smelting different steel grades is realized, iron oxide content of final slag of converter and end point product of carbon concentration and oxygen concentration are effectively reduced as well as metallurgical effects of bottom blowing system and quality of molten steel are improved.

In the paper, the alloying component system of BTP600 armor plate is designed as well as the laboratory researches on steelmaking, hot rolling and heat treatment are carried out with pilot platform. The results showed that the component system with C content of 0.42% as well as such elements as Cr, Ni, Mo and B could ensure the hardenability of BTP600 steel plate and match of impact toughness and hardness. The microstructure of as-hot-rolled steel plate is lath martensite. After tempering at 180 ℃ and 220 ℃, its boundary becomes blurry and the lath degenerates so that its length becomes shorter. With the increase of tempering temperature, the lath of tempered martensite is widened. Finally, the heat treatment process of 870 ℃ quenching+180 ℃ tempering is selected to be optimal for BTP600 armor plate, with which the impact energy at -40 ℃ could reach 15.2 J and hardness(HBW) is 624 for BTP600 steel plate.

The research on the defect of cold-lap on surface of DC04 cold rolled plate is carried out. The defect parts of the sample taken from defective cold rolled plate are analyzed by the metalloscope, scanning electron microscope and energy spectrometer. The results showed that the defect of cold-lap on surface of cold rolled plate was caused by inclusions containing such elements as C, O, Na, Mg, Al, Si and Ca as well as the inclusions are resulting from the compounds of casting powder in continuous casting process and inclusions in molten steel. The defect of cold-lap can be reduced by improving the cleanliness of molten steel, ensuring good conditions of continuous casting machine and constant casting speed as far as possible as well as reducing level fluctuation of crystallizer.

In the process of flattening and straightening, the iron oxide scale of beam steel is broken, dropped out and pressed into surface of steel coils so that pockmarks of different sizes are formed on surface, which seriously affects the appearance quality of products. In this paper, the relatedness between such process parameters as the inlet temperature of finishing rolling, rolling speed, cooling rate and coiling temperature as well as thickness and structure of iron oxide scale is researched. The results showed that the thickness of iron oxide scale was increased with the increase of inlet temperature of finishing rolling when it was below 980 ℃; the faster the rolling speed, the thinner the iron oxide scale on surface of strip steel. The defect of pockmarks on surface of beam steel is effectively controlled by optimizing the heating schedule, increasing rolling speed as well as optimizing laminar cooling rate and coiling temperature.

According to the characteristics of CSP production line of Baotou Steel, the trial production of 450 MPa grade weather resistant steel strip is carried out through adopting reasonable component design and formulating the process plan from processes of smelting to hot rolling. The good corrosion resistance is obtained with such alloy elements as Cu, Cr and Ni as well as grain refinement and precipitation strengthening are realized through microalloying of Ti and controlled rolling and controlled cooling. The microstructure and mechanical properties of optimized weather resistant steel strip Q450NQR1 are tested and analyzed. The results showed that the microstructure, grain size and mechanical properties of Q450NQR1 steel strip could meet the requirements of standard for railway steel Q450NQR1 as well as relative corrosion rate was 47.4%.

In this paper, the development process of SS105 grade rare earth microalloying seamless tube for drill pipe body resistant to H₂S stress corrosion is introduced. The designs of its chemical composition system and key production process are carried out according to the requirements of technical specification of a company and the API Spec 5DP 2020 Drill Pipe Specification as well as trial production of the product is carried out at the same time. The quality of continuous casting billet as well as chemical compositions, mechanical performances, metallographic structure and non-metallic inclusions of finished product are tested, all the indexes could meet design requirements. The effects of rare earth Ce on resistance to H₂S stress corrosion of SS105 grade seamless tube for drill pipe body are evaluated based on its service environment of the oil and gas drilling environment with high content of H₂S and low temperature. The results showed that the resistance to H₂S stress corrosion of the product was significantly improved after add rare earth into it.

In the article, the influences of changes of vanadium (V) content on microstructure and properties of high carbon steel are studied. The high carbon test steels with different technologies and V contents are tested and analyzed with the tensile test and hardness test as well as observation with metalloscope and scanning electron microscope. The results showed that there were influences of changes of V content on mechanical properties of high carbon steel. All the strength, hardness and ductility of high carbon steel could be slightly decreased with lower V content under conventional process conditions. Moreover, there are influences of heat treatment process on high carbon steel with different V contents. The ductility of low V test steel is better than that of high V test steel as well as the changes of strength and hardness for test steel are smaller through reasonably optimizing heat treatment process. Furthermore, it is found in the study that the influences of moderately reducing V content on microstructure of high carbon steel are smaller so that the changes of mechanical properties associated with microstructure are not obvious.

In the paper, it is introduced the studies on fixed flash welding process of 380HB grade high strength heat treated rare earth rail and normalizing process of joints are carried out with the common fixed flash welder and heat treatment equipment for normalizing of joints at home and abroad. The optimal welding process and heat treatment process of joints are summarized through comparing and analyzing the qualified rate of drop weight tear test, area of grey-spots and Rockwell hardness of longitudinal section for joints with different processes. For the joints of fixed flash welding for obtained 380HB grade high strength heat treated rare earth rail, the mean values of tensile strength R_m, elongation after fracture A and impact energy at room temperature KU₂ are 1 141 MPa, 12.5% and 16.0 J respectively, hardness ratios of joints H_J/H_P is 0.92, H_J1/H_P is 0.84 as well as width of softened zone for joints W≤15 mm so that the mechanical properties and microstructure of joints could all meet the standard requirements. As a result, the problems of lower hardness and drop hammer fracture of flash joint for high strength heat treated rail are solved so that the excellent performance matching of welded joints and rail could be achieved, which could meet the requirements of wear resistance and compliance for heavy-haul railway to joints of high strength heat treated rail.

The rail head of 43 kg/m rail with material of U71Mn after induction hardening by user is cracked during straightening process. The rail is inspected with such methods as the chemical analysis, fractography, metallography detection and scanning electron microscope analysis. The results showed that the chemical composition could meet standard requirements, fracture morphology of fracture origin and microstructure were abnormal, melting holes and oxidation characteristics at grain boundary could be seen locally. The offline quenching induction heating process is judged to be abnormal. Different degrees of overburning and overheating are formed in near surface area at round corner on one side of rail, i.e. oxidation and melting at grain boundary. The abnormal microstructure of coarse cementite+ledeburite is formed after quenching so that the rail is cracked in subsequent straightening process.

With the gradual development of rail transit system, bridges and building engineering to large scale and span, the strength of steel used is required to be continuously improved. As the union piece, working stress of bolt products is obviously improved and its working environment is worse so that the requirements of its strength and corrosion resistance are higher. The corrosion resistance of material is improved by adding elements of Cu and Ni as well as austenite structure of steel is finer by adding such elements of refining grain as V and Nb. As a result, the hardenability of steel is reduced and its good cold heading performance is ensured so that the cold heading steel with high strength and corrosion resistance is successfully researched and developed.

The purpose of testing water pressure of steel pipe is to confirm whether there is any water leakage with authorised pressure so as to ensure its performances to meet user requirements. In order to manage the test data for water pressure of steel pipes more effectively and improve flexibility of reports, the test data sheet for water pressure of steel pipes is established with Access database. The archiving and extraction of test data for water pressure of steel pipes are realized by using codes of WinCC VBScript and adopting mode of instruction programming so that the analytical capability for water pressure of steel pipes is improved. As a result, the archiving management of data is more user-friendly, which wins user’s recognition.