Molecular dynamics is a method of studying microstructure and properties by calculating and simulating the movement and interaction of molecules. The molecular dynamics simulation method has become an important method for studying the structural and dynamic characteristics of slag systems and can make up for the shortcomings of existing detection methods and experiments. Firstly, this paper analyzes the development process and application fields of molecular dynamics, summarizes the general simulation steps and software algorithms of molecular dynamics simulation methods, and discusses the advantages and disadvantages of the algorithms and the common functions of the software. Secondly, the research status and application progress of molecular dynamics simulation methods in the study of phosphate, silicate, aluminate and aluminosilicate are introduced. On this basis, a method of combining molecular dynamics simulation with laboratory experiments is proposed, which will help obtain more accurate simulation results. This review provides theoretical guidance and a technical framework for the effective analysis of the microstructure of different slag systems via molecular dynamics, so as to finally meet the needs of iron and steel enterprises in producing high-quality steel grades.

In view of the problems of the violent crown fluctuation and unstable shape control in the endless rolling production line, the field measurement results show that the abnormal crown fluctuation is related to the shifting limit position of the work roll after the uneven wear occurs. For this reason, the asynchronous roll shifting strategy is developed, which has double attenuation of roll shifting amplitude and roll shifting step. By coupling the roll wear contour model, the roll thermal contour model and the rolls-strip integrated model, the strip crown calculation model of the whole rolling unit is established, and the causes of abnormal crown fluctuation are revealed theoretically. In addition, the simulation analysis of the important parameters of asynchronous roll shifting strategy of double attenuation working roll is made by using this model. The number of strips in a roll shifting cycle is found to be too large or too small, which is not benefited by the control of the strip crown stability due to the influence of roll wear and roll thermal crown. A rolling unit has many shifting cycles. When the roll shifting amplitude at the end of a rolling unit is smaller, which can make the amplitude difference between adjacent roll shifting cycles greater, it is easier to avoid the uneven edge wear area and to control the strip crown stability. The industrial test shows that the maximum crown fluctuation in a rolling unit decreases by 21.05%, and the maximum crown fluctuation of adjacent strips decreases by 28.57%, which significantly improves the stability of crown control.

In this work, TiC/M2 high speed steel metal matrix composites (MMCs) were prepared using the ball milling method and laser powder bed fusing process. By controlling the TiC content in TiC/M2HSS, the grain size, phase composition, and frictional wear properties of the samples were enhanced. The results showed that when TiC/M2HSS was supplemented with 1% TiC, the surface microhardness of the samples increased to a maximum value and the wear volume decreased by approximately 39%, compared to pure M2HSS. The hardness and friction wear properties of the TiC/M2HSS composites showed a decreasing trend as the TiC content increased, owing to an increase in internal defects in the samples, as a result of excess TiC addition. The physical phases of the TiC/M2HSS MMC samples prepared by LPBF were dominated by the BCC phase, with some residual FCC phases and carbide phases. This work explored the possibility of enhancing the frictional wear performance of TiC/M2HSS samples by controlling the TiC content.

Chromium nitride powder is blended with pre-alloyed powder to make an overmatched powder with a high nitrogen concentration in order to manufacture high-nitrogen steel by selective laser melting. By employing a wider range of process parameters, the impact of process parameters on the relative density, nitrogen concentration, microstructure, and mechanical properties of high-nitrogen steel is investigated. In simulated human body fluid conditions, the corrosion resistance of high-nitrogen steel, pure titanium, and 316L was compared and evaluated. The findings demonstrate that the relative density of high-nitrogen steel initially rises and then falls with the increase in energy density, reaching a high value of 98.8% at 148.8 J/mm³. With rising energy density, the nitrogen concentration falls. The microstructure of high-nitrogen steel is mainly composed of columnar and cellular grains. Both grain sizes steadily grow, but their mechanical characteristics initially rise and then fall as the energy density rises from 83.3 to 187.3 J/mm³. With yield strength, tensile strength, and elongation reaching 921.9 MPa, 1205.1 MPa, and 27%, respectively, the alloy exhibits outstanding mechanical characteristics when the laser power is 250 W, the scanning speed is 700 mm/s, and the associated energy density is 148.8 J/cm³. The high-nitrogen steel at an energy density of 148.8 J/mm³ has the lowest corrosion rate when compared to pure titanium and 316L steel, which suggests that the HNS alloy will have good corrosion resistance in human body fluid conditions.

In the quest to produce high-strength steel, the preparation technology for vanadium–nitrogen alloy (VN) was refined through thermodynamic analysis, employing it as an additive to enhance the strength and hardness of microalloyed steel. Changes in the Gibbs free energies associated with the reactions between vanadium oxides and carbon in a nitrogen atmosphere were meticulously calculated and examined. This study explored the effects of the carbon to V₂O₅ ratio, the nitrogen to V₂O₅ ratio, and the pressure on the production of VN and CO at various temperatures. The results indicate that the productivity of VN is highest under conditions of approximately 1000 °C, a C:N₂:V₂O₅ ratio of 10:8:1, and a pressure of 1 bar. Under these conditions, VN constitutes approximately 70% of solid products, with a conversion rate of around 67.92%. CO accounts for approximately 38.17% of the exhaust gas, resulting in a yield of approximately 45.28%. The CO generated can be utilized as fuel in the production of iron in blast furnaces, providing an opportunity for secondary use of resources.

22MnCrNiMo steel, a high-strength low-alloy material, is primarily used in the production of mooring chains for offshore oil platforms, offshore wind turbines, and ships. The application of additive manufacturing technology allows for the direct fabrication of seamless mooring chains. This paper investigates the selective laser melting (SLM) process parameters for 22MnCrNiMo mooring chain steel, analyzing the effects of different process parameters on the microstructure, phase composition, and mechanical properties of the steel. The experimental results demonstrate that under the laser parameters of 200 W laser power, 800 mm/s scanning speed, 30 μm layer thickness, and 110 μm scanning spacing, the SLM-formed parts exhibit the best comprehensive mechanical properties, with a microhardness of 513.2 HV0.5, a tensile strength of 1223 MPa, a yield strength of 1114 MPa, an elongation of 8.5%, and an impact energy of 127 J. This study reveals the microstructure evolution and the mechanism of enhanced mechanical properties in SLM-fabricated 22MnCrNiMo steel, providing a new approach for the preparation of high-performance mooring chains using 22MnCrNiMo steel.