In this paper, the bending and bullet-proof properties of steel plate BTP500 are tested. The results of 90° folding test for steel plate BTP500 with thicknesses of 6 mm and 9 mm meet the requirements; the tensile strength of steel plate welded with ferritic welding wire is 100 MPa higher than that of the steel plate welded with austenitic welding wire through comparing the results of performance tests for steel plate BTP500 welded with ferritic welding wire and austenitic welding wire. The impact energy of the test plate welded with ferritic welding wire at -40 ℃ is 20~30 J and the weld test of steel plate BTP500 could meet the agreement requirements. With the penetration of bullet, both of the steel plates BTP500 with thicknesses of 6 mm and 9 mm by industrial trial production are not penetrated, which are with very good bullet-proof and anti-penetration properties as well as the bullet-proof property could meet the agreement requirements.

In the paper, the representational capacity of modified Johnson-Cook (m-JC) constitutive model on the high temperature rheological behavior of 304 austenitic stainless steel is studied. The material constants of constitutive model are calculated with the data of experimental true stress-strain for isothermal compression test at different temperatures, strains and strain rates so that the m-JC constitutive model of 304 austenitic stainless steel is established. The applicability of the model is evaluated by comparing the correlation coefficient, average relative error and mean square error of predicted results. The results showed that the average absolute relative error between the predicted results and experimental results of m-JC model was 6.77%, correlation coefficient was 0.987 as well as mean square error was 11.2 MPa so that the m-JC constitutive model could more accurately describe the rheological behavior of 304 austenitic stainless steel.

In this paper, the causes for higher burnup are obtained by analyzing the management and operations of heating furnace in detail based on the heat transfer of billet in heating furnace aiming at the phenomenon that the burnup per ton of steel of regenerative heating furnace in 1^# production line of Long Products Plant of Baotou Steel is obviously higher. A series of improvement measures and operation optimizations such as refining and strengthening the thermal management of heating furnace as well as improving hot charging rate, reducing heat losses, controlling exhaust gas temperature and reasonably controlling furnace pressure are put forward based on the working principles and operating features of regenerative heating furnace so that the gas consumption is effectively reduced, production costs are saved and certain economic benefits are obtained.

At present, the climate change has become the threat and challenge globally. As a large carbon emitter, the iron and steel industry is an important part for achieving the goal of peak carbon dioxide emissions and carbon neutrality in our country. The national carbon emission trading market, as a significant policy tool to reduce greenhouse gas emissions, provides the trading platform for contract fulfillment of carbon quota for enterprises. In the paper, the contract fulfillment scheme of carbon emission quota for iron and steel industry into the carbon emission trading market is analyzed based on the current experiences and methods for power industry participating in the carbon emission trading considering six situations that enterprises could face. Moreover, the suggestions are proposed from such aspects as the low carbon management, precision of carbon emission data and applications of low carbon metallurgical technologies to promote enterprises to transform to be green and low-carbon.

In this article, the different carbon capture technologies, utilization ways and storage technologies of CO₂, demonstration projects and commercial applications of CCUS as well as the challenges facing and development directions are systematically elaborated. Moreover, various carbon capture technologies including the absorption method, adsorption method, membrane separation and other emerging technologies are introduced as well as their feasibility of industrial-scale applications is evaluated by analyzing their principles, advantages and disadvantages; the utilization ways of CO₂ covering such fields as the chemical conversion, fuel production, mineral carbonization and agricultural applications as well as the impacts of different technologies on environmental protection and low carbon economy are discussed. Finally, such technologies as underground storage and ocean storage of CO₂ are elaborated.

The sulfuric acid corrosion resistant steel for railway carriages is with the composition design of low C containing Cr. It is with good comprehensive properties as well as its microstructure is ferrite, bainite and a small quantity of pearlite through the reasonable controlled rolling and controlled cooling process, which could meet the requirements of steel for railway carriages. The scanning electron microscope observation showed that Cu, Cr, Ni and Si were obviously enriched at the interface between oxide layer and matrix of steel. As a result, the adhesive force of oxide layer and matrix is increased to prevent permeation of anions so that the resistance to corrosion of steel surface is enhanced. The corrosion rate of the test steel in the immersion test of 20% sulfuric acid is 6.46 g/(m²·h), which is 20.59% of that of Q355B, so its resistance to sulfuric acid corrosion is excellent.

In the paper, it is elaborated the key trial production plan of 550 MPa grade low alloy high strength steel including the chemical composition, hot rolling, cold rolling and annealing processes in detail as well as studied the effects of alloy elements and production processes on microstructure and properties of products. The trial production results showed that the microstructure of 550 MPa grade low alloy high strength steel was mainly composed of ferrite and dispersed precipitated phase of TiC, its main strengthening mechanisms were fine-grain strengthening and precipitation strengthening as well as its yield strength was 556~581 MPa, tensile strength was 622~653 MPa and elongation was 14.0%~16.5%, which could meet the requirements of relevant standards and product applications.

The effects of annealing temperature on microstructure and hardness of hot-dip galvanized low alloy high strength steel strip HC420LAD+Z are analyzed through thermal simulated test machine, optical microscope and hardness test as well as it is concluded that its recrystallization temperature is 700 ℃. The changes of microstructure and properties of the steel strip at different annealing temperatures are further discussed combining the industrial productions with the measured recrystallization temperature. The results showed that the mechanical properties of steel strip were the best when annealed at 780 ℃, yield strength was 467 MPa, tensile strength was 508 MPa, elongation was 24% and the surplus was moderate, which could meet the requirements of EN 10346-2015 standard and customer use.

The independent research and development has been carried out by Baotou Steel based on the technical requirements of hot rolled coil with high strength and corrosion resistance for railway carriages. The mechanical properties and corrosion resistance of the test steel all meet technical requirements through adopting the system of low carbon+copper chromium nickel alloy and appropriate controlled rolling and controlled cooling processes. The trial production results showed that its yield strength was 550~580 MPa, tensile strength was 645~690 MPa, elongation after fracture was 20.0%~22.0%, low-temperature impact absorbing energy at -40 ℃ was 202~255 J and microstructure at room temperature was ferrite+pearlite+bainite, which was with excellent matching of strength and toughness. Its average corrosion rate is 2.813 5 mm/a, while that of Q235B is 36.060 5 mm/a, so its corrosion rate is 7.8% of that of Q235B.

The cracking sample of flash welded wheel steel 380CL for rim is detected and analyzed with optical microscope and microhardness tester. The results showed that the content of C in wheel steel 380CL exceeded the upper limit of internal control, heat with high temperature in the weld region during flash welding was fast, cooling speed was fast after weld, hardenability of weld region was improved and coarse bainite structure appeared; the microhardness of matrix and heat affected zone (HV0.1) was 303~310, while that of weld region (HV0.1) was 346, which was 12%~14% higher than that of matrix and heat affected zone, so the hardness difference was greater and ability of deformation coordination of each structure was poor when the rim flared and deformed so that they were cracked at the junction of weld seam and coarse grain heat affected zone. The weld microstructure could be refined, hardness difference of weld, matrix and heat affected zone could be reduced by strictly controlling the chemical compositions of wheel steel 380CL and reducing welding heat input so that good plasticity of weld could be ensured and cracking rate of forming for rim could be reduced.

In recent years, great progress has been made in the production technology of heat treatment for steel plate with limit specifications. The production technologies of heat treatment for steel plate with limit specifications at home and abroad are compared and introduced. The intensive production technology of heat treatment with roller quenching is adopted in China, the trial production of the thinnest steel plate (2 mm) as well as continuous and stable productions of the thickest steel plate (300 mm) have been achieved, which gradually surpass the production technologies of heat treatment adopted abroad, temperature control quenching and water tank quenching. As a result, significant contributions have been made to the large-scale, lightweight and long-service life equipment manufacturing as well as adapting to complex and harsh service environment in China.

In the paper, the technical requirements, production process control and quality performances of seamless steel pipe BT770 for crane boom produced by Baotou Steel are introduced. The seamless steel pipe BT770 for crane boom produced with the full process production process of “continuous casting billet+PQF continuous rolled seamless steel pipe+quenched-tempered heat treatment” and treatment process of external surface for steel pipe are with higher strength and toughness, good low temperature impact toughness, welding performances and surface quality.

The chemical compositions of seamless steel pipe with wall thickness greater than 25 mm for X65Q grade line pipe are designed based on low-C Mn containing steel with microalloying technology and the optimum heat treatment process is determined by laboratory study. The test results showed that the strength and low temperature impact toughness of the material matched well with the heat treatment process of “910 ℃ quenching+670 ℃ tempering”, microstructure in the steel was mainly bainite+a small quantity of tempered sorbite, grain size was 8.5 grade; low temperature impact energy of the material at -30 ℃ was over 120 J and surplus of yield strength of the material was about 80 MPa through industrial batch production testing so that the designed steel grade could be used in productions of X65Q or higher grade line pipe with wall thickness greater than 25 mm, which could meet the requirements of related performance indexes of users.

In order to study the relations between straightening process and residual stress of rails, the stress-strain situation of rails during straightening process is simulated combining with the ABAQUS software of finite element analysis. Various straightening process plans of rails are with simulation analysis to determine the optimal one and are researched combining with the results of on-site process debugging. The results showed that the minimum elastic core of each straightening plan was within deformation zoneⅡ, so the residual stress of rails could be effectively reduced by reducing the rolling reduction of 2^# and 4^# straightening rolls as well as straightening speed of rails.

The chemical composition, heating and rolling processes of hot rolled beam SM490YB are reasonably designed according to the technical standard requirements of hot rolled H beam SM490YB for offshore oil platforms in the Japanese Standard JIS G 3106-2020 “Rolled Steel for Welded Structures” combining with the characteristics of working conditions of production line in steel plant. The yield strength of the test steel with Nb-V microalloying is 412~420 MPa, tensile strength is 531~545 MPa, elongation after fracture is 26%~29%, longitudinal impact absorbing energy at -20 ℃ is greater than 200 J and transverse impact absorbing energy is greater than 110 J; microstructure of the test steel at room temperature is fine ferrite+pearlite and grain size number of ferrite is 8.5. The test results showed that the H beam with Nb-V microalloying was with good comprehensive mechanical properties, which could meet the requirements of high strength and toughness, low temperature resistance and easy to be welded for the steel for offshore oil platforms.

The composite robot consists of moving chassis with autonomous navigation and robot arm. The moving chassis is with the move function, while robot arm is with the grasping ability. Their mutual integration enables composite robots to perform more complex actions. In this article, it is developed the industrial handling system for composite robot based on the robot operating system (ROS) framework, focused on the problems of handling control and autonomous navigation with tracking for the system as well as explored how to improve its handling efficiency and accuracy. The composite robot could accurately perform handling tasks of workpieces by designing and implementing a reliable strategy of control and autonomous navigation.

In the article, the loader and unloader as well as process flow of walking beam cooler for wide and thick plate are introduced. The production status is that there is scuffing of plate during the lateral moving process of plate in walking beam cooler of production line of wide and thick plate in CSP Plant of Baotou Steel as well as plates are seriously skewed when lateral moving to the exit position so that unloading of plate cannot be carried out. The reason is the equipment wear of walking beam cooler in long-term use through analyzing, resulting in slight differences of each step of lateral moving in the two zones of cooling bed so that the cumulative deviations during the whole lateral moving process are too large. As a result, the plates are skewed in lateral moving process. The solution of compensating slight differences of each step of lateral moving in the two zones of cooling bed by adding the absolute value encoder and revision program is proposed.

In order to achieve effective logistics control for metallurgical waste slag, the intelligent management and control system is realized, in which such transportation and sale processes as contract, plan, clean transportation, weighing, confirmation of loading and unloading in stock ground as well as automatic transportation to outside of plant are integrated through the remote access and control technology, automatic license plate recognition technology with surveillance camera at guard room and development of App on cell phone. As a result, the loopholes in the processes of sales, transportation and measurement for metallurgical waste slag are eliminated as well as the cheating behaviors are completely eradicated so that the levels of measurement control and informatization management for enterprise are improved.

In order to improve the engineering construction quality and promote the construction efficiency of building engineering, construction teams need to reasonably apply digital technologies in engineering management process to meet the requirements of current era for engineering management. The feasible application strategies for digital technologies in engineering management could be formulated by analyzing the specific application values of digital management methods and application characteristics of digital technologies to promote effective reform and improvement of construction management, which makes the engineering management play a certain role in ensuring specific engineering construction process to reduce the probability of accidents so that the engineering construction could be completed as planned.

In the paper, the relations between such factors as the microstructure of rails, inclusions, excessive hydrogen and residual stress and Crack Length-Cycle curve are analyzed through the data and diagrams obtained by the tests based on the test of threshold value of crack expansion ΔK_th for U71Mn, U75V and U20Mn quenched rails as well as U75V test steel with the rare earth, lanthanum and cerium. Moreover, the effects of adding the rare earth, lanthanum alloy and cerium alloy into rails on crack growth of rails are analyzed, which could provide new means for analyzing the performances of rails and prolonging service life of rails.

The internal audit, as an important part of audit supervision, plays a role of fundamentality and source of self-regulation in the audit supervision system as well as has become the effective complement and extension of national audit. It is the significant problem faced by management layer and internal auditors of state-owned enterprises how to adapt to new circumstances, give play to the supervisory role of internal audit as well as establish the immune mechanism with self-perfection and healthy development within enterprises. In the paper, the practices and experiences of internal audit reform in enterprises are arranged and summarized from such aspects as establishment of auditing offices, construction of audit teams, analysis of auditing cases, audit rectification and achievement transformation of audit as well as the future development direction is pointed out.