Cover image credit to Susanne Schüler, B.Eng.

This article reviews the current status of research on large-size carbides in high carbon chromium bearing steels. Firstly, the morphological characteristics of three kinds of large-size carbides in steel are described. Secondly, the precipitation mechanisms of these three carbides are summarized. Finally, the common methods for regulating large-size carbides in steel are summarized.

Low-basicity fluorine-containing mold flux with NaF pores slag film is expected to solve the contradiction between heat transfer and lubrication during the continuous casting of peritectic steel. Studying the kinetic mechanism of NaF gas formation based on the NaF, CaF₂, and Na₃AlF₆ raw materials, the results show NaF material produces the most NaF gas with the lowest activation energy.

This article mainly studies the element content, phase composition, and fragmentation mechanism of SiO₂–CaO–Al₂O₃–MgO composite inclusions that cause fatigue fracture of spring steel.

In this article, a two-step Q&P process is carried out for cold-rolled medium-manganese steel (MMnS) (Fe–7.69Mn–2.76Al–0.12C wt%) to analyze the effect of composition temperature on the structure and mechanical properties of cold-rolled MMnS. In the results, it is shown that the stability of austenite is significantly affected by different partitioning temperatures. The density of face centered cubic phase error decreases obviously with the increase of partition temperature. The influence factors of austenite stability and the effect of martensitic transformation type on the deformation process are studied.

Cu and Ni elements are alloyed to an Fe–9Mn–5.5Al–0.3C low-density steel, prepared by near-rapid solidification. In the results, it is shown that nanoscale precipitates and Cu enrichment are found in the microstructure of near-rapid solidification. The precipitation strengthening and twinning strengthening contribute comparably to the strength of the alloy.

The effect of Ca addition on the evolution of inclusions, microstructures, and impact toughness of the coarse-grained heat-affected zone in the Mg-deoxidized shipbuilding steel plates after high-heat input welding of 400 kJ cm⁻¹ is investigated. Ca addition reduces the number of effective inclusions inducing the intragranular acicular ferrites formation, resulting in a deterioration of low-temperature impact toughness.

In this study, the effect of carbon content on the microstructure of three Fe–Cr–Ni duplex steels produced by rapid solidification is evaluated. In this research, using scanning electron microscopy and transmission electron microscopy for microstructural analyses, it is revealed that carbon additions change the microstructure formation from primary ferrite to primary austenite and promote the formation of M₂₃C₆ and M₇C₃ carbides.

To address the issue of low precision in rolled thickness prediction for titanium/steel-clad plates, theoretical calculation and back propagation neural network prediction models are established, respectively. In addition, three combined prediction models are built by making use of each model's advantages. By comparing the relative errors, it is shown that the Combined Model III performs better and predicts more accurately.

The flow pattern and bubble characteristics in a slab mold under argon blowing and electromagnetic stirring (EMS) are investigated using mathematical model. The flow regime within the mold shifts from bubble ascent flow to intermediate flow to horizonal recirculation flow as EMS current increases. For obtaining rational horizonal recirculation flow, it should balance the argon flow rate and EMS current.

A 3D two-phase flow model coupling volume of fluid-discrete phase model bi-directional conversion method is developed to investigate droplet behavior during slag splashing, including tracking droplet trajectories and analyzing splash rates, locations, and size distribution. The model accounts for slag-droplet interactions from top oxygen blowing, leading to the identification of an optimal flow rate of 8.80 Nm³ h⁻¹ and oxygen lance height of 233.2 mm.

Hydrogen embrittlement behavior of a prerolled Fe–15Mn–0.65C–2Al–2Si high-Mn steel with five cutting methods is investigated via hydrogen precharging and slow strain rate test. Corresponding fracture surfaces are linked to the cut-edge properties and microstructures at cutting-affected zones. The laser-cut specimens show the highest tensile ductility while the blanked specimens show the lowest tensile elongation. Previous findings imply that mechanical twinning plays a critical role in transgranular cleavage features.

From the perspective of crystallization behavior of inclusions, the eutectic region of tridymite, pseudowollastonite, and anorthite in the ternary phase diagram is the target area of CaO–SiO₂–Al₂O₃ inclusion's composition control in Si-Mn deoxidized steel. The temperature and the holding time during the hot rolling process need to be reasonably selected to avoid serious crystallization of glassy inclusions.

The neural network technology combining genetic algorithm is utilized to predict the sulfur content and optimize the desulfurization operation during the refining process. Three types of prediction models are developed to achieve the optimal model. The optimal amount of slag addition with various initial sulfur contents is also calculated.

Following Ti–Mg–Ce composite deoxidation, the number density of inclusions increases; the equivalent diameter, length, and width of the inclusions decrease, respectively; and the strength, plasticity, and toughness of the experimental steel are significantly improved, as compared to the base alloy.

The CoCrFeMnNi high-entropy alloy powder, produced through gas atomization, is introduced into a graphite die measuring 40 mm in diameter. Spark plasma sintering (SPS) is engrossed at a vacuum pressure of 0.001 Pa on HP D 25/3 SPS apparatus. These laser parameters commonly encompass factors such as scanning speed, layer thickness, and laser power, which play pivotal roles in shaping the final product's quality and properties.

The nucleation and growth of internal SiO₂ result in the formation of metal protrusions. The nucleation and growth of internal SiO₂, in combination with lateral growth of SiO₂ at the Cr₂O₃ layer/substrate interface contributed to the formation of the SiO₂ layer.

The effects of rare-earth (RE) inclusions on MnS precipitation and distribution characteristics during the solidification process are clarified through experimental methods and thermodynamic predictions, additionally, the synergistic relationship between the RE inclusions and MnS inclusions is verified with the aid of crystallography, which serves as a reference for related research on RE inclusions.

The feasibility of printing a high density, functionally gradient material (H13 tool steel–Cu) onto a wrought H13 substrate using laser-directed energy deposition, with proprietary back reflection laser technology, is investigated through varying the laser power and powder feed rates. Fundamental assessment of the compatibility of these materials is performed through differential scanning calorimetry and both optical and electron microscopy.

The flow, heat-transfer, and mixing behaviors of steel scraps with different amounts, positions, and sizes added from the top of the bottom-blown 300 t ladle are numerically investigated and compared through a coupled model. In this research, theoretical guidance can be provided for the addition of scrap in refining ladle during practical production processes.

The performance of low-grade (P₂O₅ containing) red mud-based flux in the dephosphorization of hot metal with high Si content has been evaluated with the aid of thermodynamic calculations and metal–slag equilibrium experiments in induction furnace. A substantial dephosphorization of 40% has been observed with red mud as a flux in hot metal dephosphorization processes.

In this study, orthotropic steel deck sections are optimized using Taguchi's grey relational analysis and finite-element analysis. Herein, the effects of deck thickness, welding sequence, and speed on structural performance are examined. In these findings, the critical role of welding speed, with optimal conditions identified for improved stress management and deflection control, is highlighted.

To improve the cleanliness of oriented silicon steel, industrial experiments are performed under different refining slag composition conditions. The results show that the use of medium-basicity refining slag (w(CaO)/w(SiO₂) = 2.3–2.6, w(CaO)/w(Al₂O₃) = 2.3–2.6) result in higher steel cleanliness with lower Al₂O₃ volume fraction, and smaller inclusions.

The scope of this research is to provide relationship between mechanical properties and microstructural characterization of bimetallic structure (BMS) fabricated through wire plus additive manufacturing. BMS shows better mechanical properties than wrought alloy, moreover, microstructural changes promote its use in industries requiring high-performance materials.

The inclusion transfer phenomenon under unsteady CO–Ar–molten steel flow in Rheinstahl–Heraeus (RH) is investigated in this article. The inclusion convection velocity is determined by CO/argon bubble slip velocity, inclusion slip velocity, and molten steel velocity. CO bubble plays a key role in the inclusion transfer behavior, which prompts the inclusion transport, the collision-aggregation and the removal process in RH.

The study presents an automated deep learning approach for surface defect identification using an improved RepVGG model (ViT-RepVGG), incorporating the self-attention mechanism of ViT. Various strategies for module addition and hyperparameter settings are explored, with performance compared to classic network models and recently published models, highlighting the model's effectiveness in complex industrial environments.

To improve the utilization level and energy conversion efficiency of converter flue gas, a novel technology is proposed for the online production of dephosphorization agent by utilizing the waste heat of converter flue gas. The results provide a theoretical basis for the production of slagging and dephosphorization agents, thereby achieving energy conservation and CO₂ reduction in steel industries.

A novel computational-fluid-dynamics-based model is proposed to simulate freeze-lining (FL) formation in a slag fuming furnace, coupling multiphase fluid dynamics with slag solidification. The model captures FL formation in both the slag bath and freeboard due to slag splashing. Herein, good agreement with industrial data is demonstrated, providing valuable insights into the fuming process dynamics and heat transfer.

This study presents a new method for nondestructive modeling of cord characteristics using microcomputed tomography (micro-CT). By analyzing stress–strain behavior and layered nonuniformity, the actual tensile model proves more accurate than parametric models. The findings highlight micro-CT's potential for optimizing steel cord models and predicting tensile properties, with significant industrial implications.

A laboratory-scale hot-rolled Ti–Mo–V–Nb steel with 1 GPa tensile strength is produced, and its microstructure and tensile properties are characterized using advanced analysis techniques and tensile testing. A Gleeble 3800 thermomechanical simulator is used to determine a process window. Results show significant differences in mechanical properties and fracture behavior due to the microstructural differences in different plate locations.

In this article, insights into the high-temperature deformation behavior of medium-Mn steel, which is prepared via high-ratio differential speed rolling, are provided. The microstructure of samples at typical deformation temperatures is studied using electron backscatter diffraction characterization. Moreover, through innovative bidirectional jump experiments, variations in the strain rate sensitivity index m under various conditions are obtained.

In this experiment, Ce is used to treat nonquenched and tempered steel F38MnVS. It is found that the addition of Ce forms considerable Ce-containing inclusions, which improves the morphology of inclusions. At the same time, Ce-containing inclusions promote the refinement of austenite and ferrite.

By controlling the austenitizing time, the microstructure of the subsequent heat treatment is improved, thereby improving the overall mechanical properties. Moreover, the austenitizing time can change the microstructure structure and the distribution of carbides, so that the material reduces the crack expansion area, effectively prevents crack expansion, and enhances the mechanical properties of the material.

With the diffusion concentration of O and Fe changing, the oxide layer on 9% Ni steel undergoes a phase transition from Fe₂O₃→Fe₃O₄→FeO. The uneven diffusion at the grain boundaries leads to the columnar structure of the outer oxide layer.

This study initially uses confocal scanning laser microscopy to observe the dissolution characteristics of AlN in situ in slag/flux. Subsequently, scanning electron microscopy with energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray fluorescence analyses are conducted to examine the impact of AlN dissolution slag/flux. For slag, AlN undergoes self-decomposition at 1361 °C, releasing N_2(g). For mold flux, AlN dissolution involves self-decomposition and reaction with Li₂O at 1080 °C, releasing N_2(g) and Li_(g).

This work assesses thermodynamic data for the yttrium–oxygen equilibrium in liquid iron through high-temperature experiments by utilizing high-purity Y₂O₃ crucibles as the smelting container. More reliable equilibrium constants and first-order interaction coefficients are obtained by suppressing the reactions between yttrium and the crucible and ensuring favorable kinetic conditions.

Inclusion deposition is the dominant mechanism in nozzle clogging of submerged entry nozzles. Previous modeling attempts of inclusion deposition have assumed that any contact between the inclusion and nozzle wall results in adhesion. In this work, an Eulerian-Lagrangian simulation with a stochastic adhesion model is used to study the effects of different inclusion-wall sticking probabilities on inclusion deposition.

This article proposes an eXplainable AI-based Pipeline for identifying key factors of surface defects in strip steel, which is achieved by combining data mode clustering and local model construction. The final identification results are presented by a two-stage explainable method to reveal the information of data modes and key variables and provide specific defect-related information.

This article investigates the evolution of surface transverse cracks in Q345 steel during the hot-rolling process. A slab rolling model is established based on the onsite rolling process parameters to analyze the effects of different rolling processes on the morphology and aspect ratio of surface cracks. The study summarizes the evolutionary behavior of surface transverse cracks under various rolling process parameters.

Microstructural evolution and mechanical properties of X65 seamless pipeline are investigated in the actual processes of reel-laying technology, including reel-laying installation, the lowering process, and natural aging. Little research has been conducted on a comprehensive understanding of the actual processes. The experimental results show that X65 steel is the ideal pipeline for the reel-laying technology.

Desulfurization of magnetite pellets by the isothermal hydrogen reduction process does not depend on reduction temperature and hydrogen diffusion. There is an autoxidative desulfurization mechanism during the warming process, and the desulfurization product is SO₂.

The dissimilar materials joining of advanced high-strength steel (AHSS) and glass fiber-reinforced polyamide 6 (PA 6) is achieved via laser surface texturing and injection molding. The PA 6 filling at the laser-textured AHSS creates mechanical interlocks, and the maximum joint strength is measured at 72.3 MPa.

This study introduces a novel methodology for evaluating and quantifying the protective effect that adhered slag can have on the oxidation of the refractory lining of steelmaking ladles. The article details the ad-hoc methodology itself, including the technique for adhering the slag to the refractory sample and the specifically developed equipment.