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Based on the actual working conditions of the ∅880 × 400 horizontal twin-roll caster, the influence of the rolling speed on the flow field and solidification welding line of AZ31 magnesium alloy in the roll casting area is analyzed by finite element simulation. The results show that the molten metal’s convective heat transfer efficiency is improved by two vortexes (upper and lower) in the roll casting area. When the rolling speed increases, the solidification welding line gradually approaches the outlet. And the flow velocity difference between the middle and the edge of the roll casting area gradually increases, resulting in the continuous increase of the position difference L of the characteristic solidification welding points K and K″ in the rolling direction, which increases the probability of edge cracking of the roll casting strip of magnesium alloy. In order to improve the production efficiency of the roll casting strip of magnesium alloy, it is suggested that the rolling speed should be controlled within the range of 3 ~ 4.2 m/min.

In the process of cold tandem rolling, chatter instability leads to serious impacts on enhancing rolling speed, improving product quality, reducing production cost and realizing intellectualization. Chatter occurs with the rolling speed up to a certain threshold value, but the critical speed is determined by both product specifications and rolling schedules. A 5-stand cold tandem rolling mill whose first three stands and subsequent two stands, respectively, have four and six rolls was investigated by formulating its dynamic equations with the corresponding structure–process coupling. By applying the stability-based calculation model about the critical rolling speed in each stand, the system dynamic responses around the critical rolling speed were simulated, and the system eigenvalues which represent instability and characteristic frequencies were figured out. Thereafter, via combining the critical rolling speeds with the system dynamic behavior, a dynamics-based optimization model of rolling schedule for the 5-stand cold tandem system was proposed for the purposes of both the chatter suppression and rolling speed increase. In the optimization model, eight rolling technique parameters (four strip thicknesses and four tensions between the upstream and downstream stands) were taken as design variables, and the constraint conditions were set as no chatter instability in all five stands, and the optimization goal was to maximize the outlet speed of the final stand. The pattern search method was introduced to solve the optimization model. By applying such a dynamics-based optimization model for the 5-stand cold tandem rolling process, the chatter instability was suppressed effectively and the rolling efficiency was improved considerably; therefore, such an optimization model is expected to be valuable for intelligent manufacturing of rolling process.

Magnesium-based alloys show significant promise for widespread applications owing to their lightweight nature and improved mechanical properties achieved through grain refinement via hot rolling. This investigation focuses on Mg-xAl-yCa-zMn (AXM alloys), pre-heated to temperatures of 350, 400, and 450 °C and processed via both single-pass differential speed rolling (DSR) and conventional rolling (CR). The key findings reveal the interplay between processing temperature, strain rate during single-pass rolling, and an innovative approach for incorporating varying amounts of Ca, influencing grain size, quantity of dynamic recrystallization (DRX) grains, and overall mechanical properties, including strength and ductility. A noteworthy observation is the positive correlation between an increase in the total reduction during hot rolling and a higher fraction of DRXed grains. This leads to a significant reduction in average grain size, diminishing from 60.3 ± 54.3 μm to 19.5 ± 14.2 μm at 40%, nearly a third the size of T4 grains (the initial homogenized microstructure of the AXM alloys). The resultant material strength experiences a doubling from an average of 125 ± 10.2 MPa (T4) to 260 ± 25.8 MPa (DSR rolled at 40%) for the AXM alloys with potential improvement in the ductility depending on rolling speed conditions. This study also aims to analyze the combination of rolling temperature, rolling speed, thickness reduction, speed difference and Ca content implemented across a wide range of temperatures and strain rates to provide a holistic approach to the processing parameters affecting the microstructure and mechanical properties of AXM alloys. Furthermore, this study provides a deeper understanding of DRX mechanisms, including continuous DRX (CDRX), discontinuous DRX (DDRX), and twinning induced DRX (TDRX), while each of these mechanisms plays a distinct role in the overall enhancement of formability and performance of magnesium alloys.

Recently, near-net-shape rolling has emerged as a key manufacturing technology for producing high-precision, fatigue-resistant bearing rings with irregular cross-sections, particularly for the production of Wind Turbine Shaft Bearings (WTSBs). The deformation behavior of the material during this rolling process is governed by temperature and rolling speed. Therefore, based on a thermomechanical coupled analysis, a simulation model for the deformation process of GCr15SiMn profiled rings during variable-speed rolling was developed in this study. The model was experimentally validated, confirming a dimensional error of less than 3‰. And then, the distribution of strain and temperature were analyzed during the rolling of the profiled ring. As the initial temperature increased from 1040 °C to 1160 °C, the standard deviation of strain (SDP) decreased from 6.12 to 4.05. Correspondingly, the standard deviation of temperature (SDT) was raised from 4.32 to 4.74. When the drive roll speed was increased from 2.5 rad/s to 4.0 rad/s, the SDP was reduced from 4.24 to 3.42. In addition, the SDT decreased from 4.42 to 3.21. The research indicates that SDP is primarily affected by initial temperature, whereas SDT is significantly influenced by drive roller speed. On the one hand, this study provides a clearly defined optimization framework, parameter ranges for achieving optimal uniformity in GCr15SiMn material (temperature of 1100–1130 °C, speed of 3.0–3.5 rad/s), and their anticipated benefits (an SDP reduction of 32% and an SDT reduction of 15%). On the other hand, it also establishes quantifiable industrial control targets, defining key quality assurance values (SDP ≤ 5.0, SDT ≤ 4.5). The rolling stability and precision can be improved through the selection of optimized rolling temperatures and speeds. This finding provides a theoretical foundation and technical framework for improving the rolling process stability of profiled cross-section bearing rings. Furthermore, this study is of positive significance for reducing the manufacturing costs of high-performance WTSBs.

It is known that magnesium alloys can be rolled up to a large thickness reduction and develop a unique texture when the rolling speed is high (>1000 m/min). In order to understand the texture formation mechanism during high-strain-rate deformation, high-speed rolling of AZ31 magnesium alloy samples having different initial textures was conducted. The main components of the textures after the rolling were the RD-split basal, which consisted of 10°-20° inclining basal poles from the normal direction toward the rolling direction of the sheet, regardless of the different initial textures. With preheating at 473 K, all the samples were rolled without cracking while all were cracked when preheating was not applied. The optical micrographs and EBSD measurements showed a significant amount of twins and the cracks that developed along the shear bands consisted with laminated twins. Based on the texture simulation using the visco-plastic self-consistent model, it is concluded that the rapid development of the RD-split basal component from the initial basal alignment along the transverse direction was attributable to the tension twinning, 101¯2 ⟨1¯011⟩. The effect of the initial texture on the crack formation can be explained by the activation of the twinning system.

Magnesium AZ31 alloy sheets were rolled at 100 °C at a high rolling speed of 1000 m/min. After 30% reduction, the microstructure was heavily twinned and shear banded, while a partially dynamically recrystallized and twinned microstructure was seen at the reduction of 49%. The as-rolled specimens were then annealed at 500 °C for increasing times. Microstructure and texture were characterized by optical microscopy, electron backscattered diffraction (EBSD) and X-ray diffraction (XRD). Texture weakening was found during annealing of the specimens at both reductions. However, the texture weakening was more effective in the fully twinned and shear banded specimen than the partially DRXed and twinned specimen. Effects of as-rolled microstructure on static recrystallization characteristics and texture evolution during annealing were studied.

As one of the most important structural and functional materials, rolled-product plays an irreplaceable role in national economy, people’s lives and national development. Metallurgy industry is moving from traditional semi-automation to knowledge automation, process intelligence, and manufacturing information. Rolling exerts an essential impact on material properties and product quality as an important part of the production in steel industry. Rolling process is multi-scale, multi-variable, nonlinear and unbalanced with strong coupling and non-steady state. With an increasing rolling speed, more difficulties like process information monitoring, behavior characteristics modeling, and controlling of high speed operating are manifested in high-speed continuous rolling mills. The existing control system of rolling process is difficult to cope with the condition changes of high-speed rolling and the specification changes of complex products. The main reason lies in the fact that the prediction of force parameters is based on traditional mathematical models, and the procedure parameter setting depends on static optimization methods. In order to achieve precise control of large-scale and high-speed rolling, the analysis of rolling process rules based on industrial big data should be considered to establish the dynamic process model, and multi-objective real-time computational method of rolling schedules should also be introduced. Through a summary of steel industry and a review of the history of rolling optimization, the purpose is to explore the relationship between the optimization objectives of the rolling schedule and the process parameters of the rolling process, reveal the rules of how rolling conditions affecting rolling process in high speed rolling and provide theoretical basis and technical support to the production of steel industry.

The rolling resistance of the load-bearing wheel is a key factor affecting the energy efficiency and durability of tracked vehicles. This paper investigates the friction mechanism inside the load-bearing wheel, aiming to explore the variation in friction behavior under different operating conditions through the establishment of theoretical models and simulation analysis. Due to the differences between solid rubber tires and hollow tires, the study focuses on “internal friction” to examine the force characteristics of solid rubber tires. The research results indicate that the factors influencing rolling resistance include the thickness and width of the rubber layer on the load-bearing wheel, the rolling speed of the wheel, the external load applied to the wheel, and the material properties of the rubber.

Asymmetric sheet rolling is a process used when there are differences in any technological parameters in the horizontal plane across the width of the deformation zone or in the vertical plane between the top and bottom surfaces of the deformation zone. Asymmetry can either have random causes, or it can be created purposefully to reduce rolling force, improve sheet flatness, minimize the ski effect, obtain thinner sheets and for grain refinement and improvement of texture and mechanical properties of sheet metals and alloys. The purpose of this review is to analyze and summarize the most relevant information regarding the asymmetric (hot, warm, cold, cryo) rolling processes in terms of the effect of purposefully created asymmetry on grain size and mechanical properties of pure Mg, Al, Ti and their alloys. The classification and fundamentals of mechanics of the asymmetric rolling process are presented. Based on the analysis of publications related to asymmetric rolling, it was found that a superior balance of strength and ductility in pure Mg, Al, Ti and their alloys could be achieved due to this processing. It is shown that asymmetric rolling in comparison with conventional severe plastic deformation methods have an undeniable advantage in terms of the possibility of the production of large-scale sheets.

In order to solve the problem of uneven transverse temperature distribution in the hot rolling process of zirconium alloy strip, the temperature field model of zirconium alloy strip hot rolling process was established by using the finite tolerance algorithm. The effects of initial temperature, reduction rate, rolling speed, roll temperature and strip width on the transverse temperature difference of zirconium alloy strip during multi-pass and multi-procedure rolling were analyzed. The off-line analysis of the temperature field in the hot rolling process of zirconium alloy strip provides an effective reference path for the actual control technology, which is a step towards the on-line control of zirconium alloy strip.