AZ91 magnesium alloy is a promising lightweight structural material for aerospace and automotive applications, but its poor room-temperature plasticity, rolling-induced cracking, inhomogeneous microstructure, and significant mechanical anisotropy limit its widespread use. In this work, an integrated on-line heating-rolling process was employed to fabricate high-performance AZ91 sheets. By tailoring the initial microstructure via on-line homogenization before rolling, the effects of processing parameters on microstructure evolution, texture development, and mechanical properties were systematically investigated. Results show that static recrystallization is effectively triggered during on-line homogenization. With increasing homogenization time, the {0001}//ND basal texture gradually weakens, and the coarsening of the β-Mg17Al12 phase is significantly suppressed. The sample homogenized for 100 s exhibits full recrystallization and the finest grain size (1.61 μm) after rolling, while the 200 s sample achieves the lowest texture intensity (9.54). Owing to grain refinement and precipitation strengthening, the 100 s homogenized sheet achieves optimal strength-ductility synergy along the rolling direction, with a tensile strength of 407.1 MPa, yield strength of 327.9 MPa, and elongation of 6.0%. This study provides an experimental and theoretical basis for the short-process fabrication of high-performance high-aluminum magnesium alloy sheets.

This study systematically investigates how conventional unidirectional rolling (UR) and cross-rolling (CR) routes influence the microstructure and mechanical properties of AZ91 magnesium alloy, providing crucial insights for developing high-performance, near-isotropic magnesium alloy sheets. The microstructure of the magnesium alloy was examined using techniques such as scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy. The investigation demonstrated that the initial CR pass produced sheets featuring multi-directional slip bands and a bimodal texture, which provided nucleation sites for discontinuous dynamic recrystallization (DDRX) during subsequent deformation. The second CR stage produces a fine-grained microstructure with an average grain size of 1.76 mu m, featuring uniformly distributed nanoscale precipitates and a recrystallization fraction of 73.4 %. DDRX significantly weakens the basal {0001}//ND texture to a minimum intensity of 10.95, enabling the development of near-isotropic mechanical properties. The optimal RTR processing route (RD-*TD-*RD) achieves an exceptional strength-ductility synergy, with tensile strength reaching 371.6 MPa (RD) and 368.0 MPa (TD), yield strength of 310.6 MPa (RD) and 304.3 MPa (TD), and elongation of 7.9 % (RD) and 8.2 % (TD). This enhancement stems from the synergistic effects of grain refinement, precipitation strengthening, and texture randomization mediated through DDRX activation at multi-directional slip bands. Notably, the optimized RTR process achieves this balanced performance using conventional rolling equipment without requiring complex procedures, demonstrating strong potential for industrial applications where consistent multi-directional properties are essential.

In this research, Cu-Fe alloys with Fe compositions of 5, 10, 20, and 30 % were successfully fabricated using a novel spray-forming method and followed by cold rolling. The impacts of varying Fe compositions on solidification behavior, microstructure evolution, and mechanical characteristics were systematically investigated using various analytical methods, including OM, EPMA, XRD, SEM, EBSD, and TEM. The findings demonstrate that the Fe particles of the spray-formed Cu-Fe alloys with all components exhibit a fine and uniform distribution within the Cu matrix. With the increase in Fe compositions, the average grain diameter of the Cu matrix is obviously refined. The deformation behavior and the reinforcement mechanisms of Cu-Fe alloys with different Fe compositions during cold rolling were also explored. After cold rolling, Cu grains and Fe grains were distinctly refined and stretched into fibers in the rolling direction. The extent of Fe fibers became more pronounced as the Fe composition. The Cu matrix formed strong copper and brass textures. The strength of the spray-formed Cu-Fe alloy after cold rolling increased as the Fe composition increased. The enhanced strengthening effect of the alloy is predominantly attributable to a synergistic combination of high dislocation density within the Cu matrix, grain refinement, and Fe grain fibrillation. Furthermore, the strengthening mechanism of the spray-forming Cu-Fe alloy after cold rolling aligns with the Hall-Petch relationship. The research lays a solid foundation for the preparation and industrial production of Cu-Fe alloys with high Fe compositions.

Three-way servovalve controlled cylinder (TSCC) is the main method used in hydraulic automatic gauge control (HAGC) system of rolling mill, which generally only foucus on the screw-down speed of HAGC cylinder under load resistance. However, with the development of plan view pattern control and variable gauge rolling, the lifting-up speed of HAGC cylinder is required to be as high as the screw-down speed. At present, high frequency response and large flow servovalves or even double servovalves in parallel are usually used to achieve high lifting-up speed, resulting in a substantial increase in equipment cost. In this paper, the nonlinear mathematical models of the TSCC and four-way servovalve controlled cylinder (FSCC) are firstly established, and the steady-state speed equations of the two methods are derived. Then, the steady-state speed of the two methods with different HAGC cylinder sizes under different load conditions is compared and analyzed, and it is proved that FSCC has obvious advantages in lifting-up speed. Finally, simulation experiments of variable gauge rolling on a 1 050 mm cold-rolling mill are carried out. In the rolling process of transition zone where the roll gap increases, the FSCC has higher control precision and wider dynamic adjustment ability, which is more conducive to improving rolling speed, production efficiency and shape quality.

In order to solve or suppress the problem of macro segregation of Fe phase of Cu-Fe alloy in the traditional casting process, we successfully prepared Cu-10Fe alloy prefabricated slabs with homogeneous and fine microstructure by spray deposition and achieved high strength Cu-10Fe alloy thin strips by subsequent cryorolling. Cryorolling was carried out at different reductions to investigate the relationship between microstructure evolution and mechanical properties. The results show that the spray deposited alloys have good plasticity and low temperature workability. As the reduction increased, the Fe phase becomes more fibrous and the average grain size of the alloy is refined to 0.35 μm. The {112}<111> texture was gradually transformed into a stabilized {110}<112> texture during cryorolling suggested that the low temperature suppressed cross-slip and improved the strength of the alloy. The mechanical properties of the alloys improved significantly after cryorolling is mainly attributed to the significant grain refinement, dislocation accumulation and the presence of ultrafine grains during the cryorolling process. The successful development of thin strips of Cu-Fe alloy with uniform distribution of Fe phase and high strength provides a new idea for the preparation of thin strips of immiscible alloys such as Cu-Fe alloy.

In the hot rolling process, strip shape is a great factor in assessing the quality of non-oriented silicon steel products. As the downstream industry has increasingly quality requirements for silicon steel products, the traditional predictive model is unable to meet the demand for silicon steel control. In order to improve the accuracy of the pre-set crown model, a stochastic configuration network (SCN) is used to build a data-driven crown prediction model. Additionally, we conduct correlation analysis of all features using Spearman correlation analysis to mitigate the influence of redundant variables. To improve the network ' s performance, we investigated the effect of weights and biases on SCN performance in four different distributions. We utilized a zero-symmetric distribution with adaptive parameters to decrease the model ' s training time and enhance its generalization performance. The results indicate that the model achieved the highest prediction accuracy under the normal distribution of adaptive parameters, with the correlation coefficient of 0.9483. The accuracy of crown deviation within +/- 5 mu m is 96.3 %, the root mean square error and the mean absolute error are 2.525 and 1.925 respectively. Furthermore, the model prediction results were used to analyze the impact of four key rolling parameters on the crown of silicon steel. Compared to the original SCN, this method can effectively enhance the prediction accuracy of the silicon steel crown.

Tension control in cold-rolling pilot mills (CRPMs) with hydraulic tension is subject to extraneous forces resulting from positional disturbances, strong coupling, and time-varying characteristics, making it challenging to achieve ideal control results using the existing control methods. Therefore, in this study, a mathematical model of tension is first derived and then used to analyze the properties and difficulties associated with tension control. Second, a hydraulic servo-control system based on servovalves and proportional pressure relief valves is developed. In this system, redundant feedforward flow is generated by a servovalve according to the rolling schedule. The surplus flow is absorbed by a proportional pressure relief valve in the closed-loop control of tension. Third, simulation analysis is performed. Under severe friction disturbance (maximum 0.2 kN), and with the wide range of forward and backward slip, an accuracy of ±0.27 kN in tension control can still be achieved using the proposed control strategy, thereby demonstrating its effectiveness. Moreover, it has obvious advantages over existing control methods. Finally, an experimental study of tension is carried out in the cold-rolling mill with a maximum tension capacity of 50 kN, achieving ±0.2 kN tension control precision in the multipass rolling process.

In order to obtain homogeneity and fine-scale microstructure of Cu–Fe alloy, a Cu-10 wt

To address the challenges associated with preparing thin strips of difficult-to-deform materials - such as low processing efficiency and yield, poor shape, and subpar performance our research team developed an on-line warm rolling experimental machine featuring hydraulic tension. We used the Ti-6Al-4V alloy as our experimental material and conducted warm rolling experiments at various temperatures, thoroughly examining the intricate relationship between microstructure evolution and mechanical properties. Our findings indicate that warm rolling causes a clear refinement of the a phase and b phase microstructures, while intensifying dislocation entanglement. These changes significantly enhance the strength of the Ti-6Al-4V alloy, though Total Elongation Limit (TEL) decreases. After evaluating mechanical properties, surface quality, and energy consumption associated with warm rolling, we determined the optimal warm rolling temperature for the Ti-6Al-4V alloy to be 650 degrees C. At this temperature, the Ultimate Tensile Strength (UTS), Yield Strength (YS), and TEL were 1325 MPa, 1164 MPa, and 8.0%, respectively, maintaining good ductility. The impressive performance of the Ti-6Al-4V alloy sheet is mainly attributed to the strengthening effects of fine grain and dislocation, while the introduction of some fine recrystallization enhances ductility. High-performance Ti-6Al-4V alloy thin strip was successfully prepared by on-line warm rolling with hydraulic tension, which provided a new idea for the preparation of thin strip of difficult-to-deform materials. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC

As an emerging technology in the production of electrical steel, edge‐drop control (EDC) caters to the increasing requirements for the overall shape quality of strips. Herein this review, the development of EDC theory, method, and control system used in the cold‐rolling process is summarized. Also, in this review, research on EDC theory is found to be based on the 3D plastic deformation model of the strip, considering the lateral metal flow. Further, an analytical model and a numerical calculation method are employed to establish an edge‐drop calculation model with high accuracy and speed. Next, taper‐work‐roll shifting (T‐WRS), a conventional EDC technology, is found to have been greatly improved in actual production. However, T‐WRS technology involves coupling problems in terms of edge drop and crown and flatness control. Finally, the closed‐loop EDC is found to depend on the online WRS of multiple stands. Particularly, the genetic law of strip thickness in the continuous rolling process and the edge‐drop regulation characteristics of each stand in the continuous rolling mill are significant aspects; thus, a reasonable roll‐shifting control strategy must be formulated. Based on the reviewed research, the development prospect of EDC is characterized.

Ti-6Al-4V alloy warm rolled sheets with different initial grain sizes were obtained by warm rolling with different reduction rates. In order to improve its strength-ductility matching, it was treated by vacuum solution treatment (ST). By means of OM, SEM, EBSD, TEM, EPMA and XRD, the effects of different initial grain sizes of warm rolled sheet on the microstructure and mechanical properties of vacuum ST. The findings indicate that the initial grain sizes significantly influence the grain size, morphological distribution, and mechanical properties following vacuum ST. By warm rolling 60% combined with subsequent solution treatment (ST-60%), the grain size of the primary alpha phase (alpha(p)) and the beta transformed (beta(t)) structure is minimized, predominantly fine and equiaxed, with a dense distribution. This results in an optimal strength-ductility balance, with ultimate tensile strength, yield strength, and total elongation measuring 1283 MPa, 1194 MPa, and 10.5%, respectively. The volume fraction, grain size, morphological distribution, and the acicular alpha phase (alpha(s)) of alpha(p) and beta(t) structure are among the factors influencing their mechanical properties. Furthermore, the solution strengthening of Aluminum (Al) in alpha(p) during the ST significantly increases the nano-hardness of as compared to beta(t) structure. This disparity leads to a plastic strain distribution between ap and beta(t) structure, activating a substantial amount of Geometrically Necessary Dislocations (GND) near the beta(t)/ alpha(p) interface. This provides additional Hetero-Deformation-Induced (HDI) strengthening, thereby maintaining high strength and good ductility.

In this study, the microstructure and mechanical properties of AZ31 magnesium alloy were investigated through asynchronous rolling. The results demonstrate that the rolled sample exhibits a refined grain structure with a significant presence of continuous dynamic recrystallization. Notably, as the roll speed ratio increases, the grain refinement becomes more apparent. For the sample with a roll speed ratio of 1.3, the tensile strength in the rolling direction (RD) reaches 273 MPa, while the elongation measures 20.2%. Similarly, in the transverse direction (TD), the tensile strength reaches 282 MPa, accompanied by an elongation of 18.9%. These values indicate a substantial improvement in elongation compared to conventional rolling processes. The enhanced elongation can be attributed to two primary factors. Firstly, recrystallization contributes to a grain refinement recrystallization ratio of 86%, promoting improved mechanical properties. Secondly, the recrystallized grains induce a favorable Schmidt factor, further supporting elongation. Overall, the findings of this research highlight the benefits of asynchronous rolling in refining the microstructure and enhancing the mechanical properties of AZ31 magnesium alloy.

为促进小班化教学质量的稳定性和均衡性,增强学生参与感和获得感,利用监督评价和学生评价信息对材料成形自动控制基础课程教学协同状态进行内观和及时调整,利用教学目标达成评价结果对各班教学情况、学生学习和考核情况进行总结,推动课程团队教师采取更有效的措施,提升教学质量和水平.

将科研成果与教学内容融合,进行特色创新,拓宽学生视野,通过具体科研实例,培养运用知识解决实际问题能力.在知识传授的同时进行价值引领,通过课程中贯穿始终的思政教学,使学生具备社会责任感和工程职业道德、组织管理能力和终身学习能力等基本素质.

同步马达在多液压缸同步控制中具有广泛的应用,但由于各液压缸之间的工况差异,偶尔造成同步误差偏大且难以解决的问题.利用MATLAB建立同步马达控制四缸同步提升系统的SimHydraulics模型并进行仿真研究,通过控制变量法研究确定了同步马达控制方式下同步误差的主要影响因素,并在此基础上提出一种基于均值偏差进行换向阀流量补偿的控制策略.仿真结果表明,该控制策略能够有效消除由于工况差异造成的同步误差.

A pure Ni interlayer with a thickness of 0.1 mm was introduced between high-strength interstitial free steel and Al–Mg–Si alloy, which were friction stir lap welded, producing an excellent welded joint. The interface layer consisted of a γ-Ni solid solution, and the mixed stirring zone contained alternate lamellae of γ-Ni and α-Fe solid solutions. The addition of a Ni interlayer strongly suppressed the reaction between Al and Fe because of the atomic arrangement of Ni. Furthermore, the insertion depth of the stirring pin has a significant influence on the Al/steel interfacial reaction. Under shallow insertion depth, the intermetallic compounds of both FeAl and Fe2Al5 were observed at the interface layer. A maximum tensile-shear fracture load of 4.3 kN was achieved, with fractures being present in the steel substrate far away from the Al/steel weld.

Traditional Mizushima automatic plan view pattern control system (MAS) can improve plate rectangular to some extent; as setting curve is not fine, and products yield cannot be further improved, controllable points setting method for plan view pattern control (PVPC) in plate‐rolling process is proposed. Prediction model of head metal flow pattern including broadening coefficient is deduced, Gaussian mixture model is introduced, and three Gaussian curves with different shapes are weighted to obtain functional expression. To study the influence of different controllable points setting and relationship between the elongation coefficients, finite element method is used with different broadening and elongation ratio; simulation results show that different points setting can get similar cut loss length when the broadening ratio equals 1.45, but either the broadening ratio decreases to 1.15 or increases to 1.75, the cut loss with more set points can be decreased to a great extent. Practical application show that comprehensive yield with traditional PVPC is 92.28%, and comprehensive yield is significantly improved to 93.36%, as PVPC with controllable points method is used without reducing the efficiency of production. It creates remarkable economic benefit for enterprises and greatly enhances their competition ability.

A set of thermoforming equipment was developed by State Key Laboratory of Rolling and Automation, based on thermoforming with high inner atmospheric pressure theory, to study thermoforming process of ultra-strength steel pipes. The resistive heating was used to accurately control the temperature of the pipes. The high-pressure sealing structure of pipe ends, rapid inflation system and hydraulic servo system were designed. The heated pipes were shaped under the action of both high inner atmospheric pressure and axial feed. By means of the mold inner loop cooling circuit designed, the pipes touched the cold mold and were quenched directly. Therefore, pipe heating, forming and quenching were finished in single-position. The experiment results show that maximum gas pressure reaches 40 MPa with the sealing effect reliable. Temperature control accuracy is ± 1 ℃ and the inflation velocity can be adjusted continuously. The equipment provides reliable support for the research of ultra-strength steel pipe thermoforming process with inner high atmospheric pressure.