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So-called center and edge segregation are formed during twin-roll casting, which cannot be effectively eliminated in subsequent rolling and heat treatment, thus significantly diminishing the quality of final product. Numerous studies have been conducted on such segregations so far, unfortunately, without fully considering conservation of mass, momentum, energy and solute throughout the process, as well as synergy of thermodynamics and kinetics for interfacial migration. Accordingly, a two-phase Eulerian-Eulerian volume-averaged model is herein established to predict the segregation upon twin-roll casting for Al–Si alloys, which, for the first time, addresses effects due to the interfacial migration and the solute diffusion on the solute transfer process, and so-called correlation between thermodynamics and kinetics (i.e., thermo-kinetic correlation). On this basis, the model accurately predicts the flow field upon twin-roll casting, where, the increased casting speed leads to the descended kissing point, thus gradually causing the decreased vortex area and the increased cooling rate. Whereas, the increased heat transfer coefficient leads to the ascended kissing point, thus gradually causing the increased vortex area and the decreased cooling rate. In the modeling, the increased thermodynamic driving force for interfacial migration is always accompanied by the decreased kinetic energy barrier, and vice versa. Furthermore, the model also accurately predicts the segregation upon twin-roll casting, where, the thermodynamic driving force increases with the casting speed, thus decreasing the central segregation, whereas, the heat transfer coefficient increases, thus enhancing the generalized stability and in turn, effectively suppressing the edge segregation. By employing a strategy involving high driving force in the early stage and high generalized stability in the late stage, it was determined that the anticipated center and edge segregation could be effectively suppressed.

The cold rolling and intermediate annealing process, along with the incorporation of rare earth elements, play an important role in the microstructure, texture, and inhibitors of oriented silicon steel. Currently, there is limited research on the impact of rare earth yttrium on texture evolution during the cold rolling and intermediate annealing processes. Therefore, the effects of different cold rolling deformations and intermediate annealing temperatures on the microstructure and texture of Y bearing oriented silicon steel have been studied. The experimental results demonstrate that the average grain size of the intermediate annealed plate progressively decreases with increasing the cold rolling deformation. This is because the high cold rolling deformation brings more additional dislocations and distortions, consequently enhancing the driving force for recrystallization. Observing the microstructure with various cold rolling deformation, the results show that the annealed plate with a 72 % reduction rate exhibited the highest Goss texture percentage of 4.83 %. This is because the cold-rolled sheet with a reduction rate of 72 % exhibits an abundance of Goss oriented substructures. These substructures quickly dominate the {111} deformed matrix during the initial recrystallization, and promote grains nucleation and growth. As the annealing temperature increases, the driving force for the growth of recrystallized grains also increases, leading to a gradual increase in grain size. The plate annealed at 940 °C exhibits the highest percentage (4.83 %) of Goss texture. The addition of rare earth Y can lead to an increase in grain size in the intermediate annealed plate and facilitate the formation of {411} texture. This is advantageous for the abnormal growth of Goss texture. The results demonstrate that a cold rolling deformation rate of 72 % and an intermediate annealing temperature of 940 °C are good for promoting abnormal growth of Goss orientation. The study results on precipitation kinetics suggests that the grain boundary nucleation of AlN and dislocation nucleation of MnS are the most effective way of nucleation. The precipitates in oriented silicon steel without Y are Al2O3 and MnS, while those in the samples with Y are AlN, YS, and YOxSy. The addition of rare earth Y leads to a reduction in both the density and size of precipitates. Moreover, With the increase of annealing temperature, the size of precipitates decreases and the amount of precipitates increases. Additionally, the addition of Y makes the steel more clean, meanwhile, the pinning effect of inclusions on grain boundaries is weakened. Therefore, the grain size of the steel with Y is larger.

Low temperature heating process of the slab has become the mainstream process for producing high quality oriented silicon steel due to its environmental protection, low cost, and high yield. For this process, the number of inhibitors is less and the size is large, resulting in insufficient inhibition, coarsen grains during primary recrystallization, and insufficient driving force for secondary recrystallization, which reduces the magnetic properties of the product. These shortcomings can be improved by optimizing the inhibitors and normalizing processes. The effects of normalizing processes on the microstructure, texture, and precipitations of low-temperature oriented silicon steel containing Sn were studied by OM, SEM, TEM, and EBSD with Fe–3%Si hot-rolled plate as initial material. The experimental results show that the sample has the best performance in terms of microstructure, texture, and precipitations with the two-stage boiling water cooling normalizing process that the heating temperature is 1150 °C, and the normalizing intermediate temperature is 850 °C. With the above parameters, the microstructure is inhomogeneous along thickness. There are more {111} textures, which are favorable to the growth of Goss texture. The proportion of high energy grain boundary reached 54.2%. The precipitates are significantly refined, which enhances the ability to inhibit primary recrystallization. The sub-surface thickness of the hot rolled plate increases from 40.6% to 62.1% with increasing Sn content from 0.01% to 0.11%. The degree of tin segregation at grain boundary increases with the increase of normalizing temperature and the decrease of medium soaking temperature.

The impact of shear deformation on texture evolution in strip-cast Fe-1.5%Si non-oriented electrical steel was studied combined with in-suit experiments and crystal plasticity finite element method (CPFEM). Throughout the deformation process, the texture evolution predominantly follows a traditional route: transitioning from {211} and {411} to {111} orientation. In certain regions with specific stress conditions, orientation evolution shifts from {310} to {411}, {100}, and finally to {100} orientation. Crystal plasticity finite element (CPFE) simulation results show that the rotation of {310} through {411} to {100} orientation, {211} and {112} orientations transition to {111} and {110} orientations, respectively, which is consistent with the experimental observations. Recrystallization texture mainly includes favorable λ and near-λ (∥ND, normal direction) textures, with detrimental γ (∥ND) texture essentially diminishing. In-situ heating experiments revealed {411} as the primary recrystallization orientation, the mechanism involves both oriented nucleation and growth. In the edge region lacking stress constraints, the Schmid factor (SF) reaches up to 0.48, the (21-3)[111] slip system is preferentially activated, with shear bands appearing earlier in the same region. Indicating that when slip mechanism alone are inadequate for sustaining plastic deformation, the shear deformation becomes the favored mode of activation. {411} orientation can serve as a transitional orientation for transitioning to {100} orientation, and further as an advantageous transitional orientation during the nucleation and growth of recrystallization. Due to the texture improvement, superior magnetic properties were achieved, with the average magnetic induction (B50) and iron loss (P1.5/50) being 1.77 T and 4.25 W/kg, respectively.

The role of inhibitor behavior in abnormal growth of Goss grains during secondary recrystallization was studied in combination with experimental observation and phase-field model simulation in grain-oriented silicon steel. The frequency advantages of both HE (high energy) and CSL (coincidence site lattice) grain boundaries around Goss grains over the matrix were identified, with frequency advantages of ∼15% and ∼2% respectively. The HE grain boundary was supposed to play a more important role in abnormal grain growth over CSL grain boundary in this study. The boundary character distribution was necessary but not sufficient for the abnormal growth of Goss grains. Appropriate inhibitor behavior was a prerequisite for secondary recrystallization. The initial content and stability of inhibitor played a key role in stabilizing the matrix, which guaranteed beneficial fine grains around Goss grains. While if the inhibitor force rapidly declined, matrix grains might grow obviously, resulting in coarsened grain colonies with Cube, {112}, {111}, {411}and {210} orientation, which further hindered the abnormal growth of Goss grains. The candidate Goss grains with different misorientations competed with each other during secondary recrystallization and the exact Goss grain exhibited an obvious growth advantage. Only with an appropriate pinning force and grain boundary character, perfect secondary recrystallization can be achieved. The present findings can provide guidance to understand and precise control of abnormal grain growth phenomenon.

Ulcerative colitis (UC), as a chronic inflammatory disease, presents a global public health threat. However, the mechanism of Poria cocos (PC) in treating UC remains unclear. Here, LC-MS/MS was carried out to identify the components of PC. The protective effect of PC against UC was evaluated by disease activity index (DAI), colon length and histological analysis in dextran sulfate sodium (DSS)-induced UC mice. ELISA, qPCR, and Western blot tests were conducted to assess the inflammatory state. Western blotting and immunohistochemistry techniques were employed to evaluate the expression of tight junction proteins. The sequencing of 16S rRNA was utilized for the analysis of gut microbiota regulation. The results showed that a total of fifty-two nutrients and active components were identified in PC. After treatment, PC significantly alleviated UC-associated symptoms including body weight loss, shortened colon, an increase in DAI score, histopathologic lesions. PC also reduced the levels of inflammatory cytokines TNF-α, IL-6, and IL-1β, as evidenced by the suppressed NF-κB pathway, restored the tight junction proteins ZO-1 and Claudin-1 in the colon, and promoted the diversity and abundance of beneficial gut microbiota. Collectively, these findings suggest that PC ameliorates colitis symptoms through the reduction in NF-κB signaling activation to mitigate inflammatory damage, thus repairing the intestinal barrier, and regulating the gut microbiota.

The evolution of shear band (SB) and texture in strip-cast electrical steel was studied in order to investigate the crystallographic character of SB and its influence on recrystallization texture. Shear deformation in the form of SB played an effective role in tailoring the local lattice rotation to accommodate heavy deformation in the case of inhomogeneous deformation under conditions of initial coarse grain in strip-cast electrical steel. During rolling process, η-oriented SBs appeared at different stages of deformation as a result of geometric softening. Cube-oriented SB was mainly retained from initial exact Cube grain at early stage of shear deformation and Goss-oriented SB was newly developed during the formation of γ-fiber matrix after heavy deformation. {210} SB formed as a transition form among different SBs. Crystal rotation inside SB, SB dimension and SB boundary misorientation progressed in proportion to cold rolling reduction. It is demonstrated that crystallographic direction of SBs tended to be parallel to under the driving force of reduction in stored energy to maintain relatively quasi-stable state. Low orientation gradient as well as relatively low density of dislocations was developed within SB region, while high orientation gradient formed between SB region and surrounding matrix. Interestingly, the η-oriented cell blocks inside SBs provided preferential nucleation sites for Goss and Cube texture at early stage of recrystallization, which significantly contributed to beneficial recrystallization texture in a manner of texture inheritance and superior magnetic properties (B50 was as high as 1.81 T, and P1.5/50 was as low as 4.0 W/kg).

Accurate segmentation of the medical image is the basis and premise of intelligent diagnosis and treatment, which has a wide range of clinical application value. However, the robustness and effectiveness of medical image segmentation algorithms remains a challenging subject due to the unbalanced categories, blurred boundaries, highly variable anatomical structures and lack of training samples. For this reason, we present a parallel dilated convolutional network (PDC-Net) to address the pituitary adenoma segmentation in magnetic resonance imaging images. Firstly, the standard convolution block in U-Net is replaced by a basic convolution operation and a parallel dilated convolutional module (PDCM), to extract the multi-level feature information of different dilations. Furthermore, the channel attention mechanism (CAM) is integrated to enhance the ability of the network to distinguish between lesions and non-lesions in pituitary adenoma. Then, we introduce residual connections at each layer of the encoder-decoder, which can solve the problem of gradient disappearance and network performance degradation caused by network deepening. Finally, we employ the dice loss to deal with the class imbalance problem in samples. By testing on the self-established patient dataset from Quzhou People’s Hospital, the experiment achieves 90.92% of Sensitivity, 99.68% of Specificity, 88.45% of Dice value and 79.43% of Intersection over Union (IoU).

The development of a high-performance, low-cost, and simply fabricated flexible three-dimensional (3D) force sensor is essential for the future development of electronic skins suitable for the detection of normal and shear forces for several human motions. In this study, a sandwich-structured flexible 3D force tactile sensor based on a polyethylene-carbon composite material (velostat) is presented. The sensor has a large measuring range, namely, 0–12 N in the direction of the normal force and 0–2.6 N in the direction of the shear force. For normal forces, the sensitivity is 0.775 N−1 at 0–1 N, 0.107 N−1 between 1 and 3 N, and 0.003 N−1 at 3 N and above. For shear forces, the measured sensitivity is 0.122 and 0.12 N−1 in x- and y-directions, respectively. Additionally, the sensor exhibits good repeatability and stability after 2500 cycles of loading and releasing. The response and recovery times of the sensor are as fast as 40 and 80 ms, respectively. Furthermore, we prepared a glove-like sensor array. When grasping the object using the tactile glove, the information about the force applied to the sensing unit can be transmitted through a wireless system in real-time and displayed on a personal computer (PC). The prepared flexible 3D force sensor shows broad application prospects in the field of smart wearable devices.

Twin-roll strip casting (TRSC), which is a low-energy and short process to produce strip steel, is a potential approach to produce advanced high-strength steels. Herein, a medium-Mn steel containing 4 wt% Mn was processed using a novel route involving TRSC, hot rolling and quenching and partitioning (QP) to explore the possibility of medium-Mn steel produced by TRSC plus QP process. The effects of quenching temperature on the microstructure and mechanical properties were studied. It was found that primary martensite and retained austenite (RA) were obtained at the quenching temperature of 140–180 °C, while primary martensite, RA and secondary martensite were obtained when the quenching temperature was 220–300 °C. With an increase in quenching temperature from 140 to 260 and to 300 °C, the RA fraction first increased from 15.4% to 31.8% and then decreased to 16.6%. The sample at a quenching temperature of 220 °C yielded mechanical properties with a yield strength of 992 MPa, tensile strength of 1159 MPa and total elongation of 20.4%. The superior mechanical properties were achieved by an optimum combination of high RA fraction (26.5%), appropriate mechanical stability of RA and a small number of the islands of secondary martensite and RA. Hence, the present study provides a viable processing route for medium-Mn steel.

An electrode material with high performance, long durability, and low cost for supercapacitors has long been desired in academia and industry. Among all the factors that affect the electrochemical performance and cycling stability of electrode materials, the morphology and intrinsic structure characteristics are the most important. In this study, a novel 3D flower-like Ce(COOH)3 electrode material was designed by taking advantage of the Ce3+ and -COOH groups and fabricated by a one-pot microwave-assisted method. The morphology and structure characteristics of the sample were examined by SEM, EDS, TEM, XRD, FT-IR, XPS, N2 adsorption/desorption techniques, and the electrochemical behaviors were investigated in a three-electrode configuration. The Ce(COOH)3 electrode presents an excellent specific capacitance of 140 F g−1 at 1 A g−1, higher than many other previously reported Ce-based electrodes. In addition, it delivers high rate capability that retains 60% of its initial capacitance when the current density is magnified 20 times. Dramatically, the Ce(COOH)3 electrode exhibits an ultra-high cycling stability with capacitance retention of 107.9% after 60,000 cycles, which is the highest durability among reported Ce–organic compound electrodes to the best of our knowledge. The excellent electrochemical performance is ascribed to its intrinsic crystal structure and unique morphology. This work indicates that the 3D flower-like Ce(COOH)3 has significant potential for supercapacitor applications and the facile and scalable synthesis strategy can be extended to produce other metal–organic composite electrodes.

The predication of the helium diffusion concentration as a function of a source term in diffusion equation is an ill-posed problem. This is called inverse radiogenic source problem. Although some classical regularization methods have been considered for this problem, we propose two new fractional regularization methods for the purpose of reducing the over-smoothing of the classical regularized solution. The corresponding error estimates are proved under the a-priori and the a-posteriori regularization parameter choice rules. Some numerical examples are shown to display the necessarity of the methods.

To investigate the influence of heavy rare earth element yttrium on the type, morphology, and quantity distribution of inclusions in grain-oriented silicon steel, thermodynamic calculation was carried out on the typical rare earth inclusions in grain-oriented silicon steel containing yttrium. The main inclusions in the experimental steels with and without yttrium were observed and analyzed using field emission scanning electron microscope (FESEM, Zeiss Gemini SEM 300) and energy dispersive spectrometer (EDS, OXFORD Ultim Extreme). The electron backscatter diffraction (EBSD, OXFORD Symmetry) was used to analyze the local average misorientation of the hot-rolled plate. The results show that the inclusions in the Y-free steel are mainly long MnS, irregular Al2O3 and MnS-Al2O3. The inclusions in the Y-bearing steel are spherical rare earth compounds. The number of inclusions in Y-bearing steel decreases and the size increases compared with Y-free steel. The mean value of local average misorientation and the dislocation density of Y-bearing steel are smaller compared with Y-free steel, which could avoid the cracking problem caused by dislocation accumulation during hot rolling. After heating the rough-rolling sample to 1350 °C, there is no obvious difference in the inclusions type between the Y-free steel and Y-bearing steel. However, the area fraction of inclusions in Y bearing steel increases slightly. According to the thermodynamic calculation results, there are mainly three kinds of rare earth inclusions, YS, Y2S3 and Y2O2S, in Y-bearing steel, among which YS has the strongest stability and the stability of Y2O2S is the weakest. The rare earth element yttrium can effectively modify the inclusions, transforming the irregular Al2O3 inclusions, formed during the deoxidation of silicon steel into spherical rare earth inclusions, which suppress the precipitation of long MnS inclusions. Thus, the formability of the steel could be improved.

The grain structure has a great influence on the mechanical reliability of miniaturized interconnect circuits. Under the working conditions, Cu3Sn will be the main intermetallic compound that forms during electromigration and the thermal ageing process, which can easily induce cracks between Cu3Sn and the copper pad. This paper investigated the effect of the Cu grain structure on the Cu3Sn/Cu interface reliability via molecular dynamic simulations. Single-crystal Cu, twin-crystal Cu, and polycrystalline Cu models were implemented to form the interface structure, and uniaxial tension simulations were performed at strain rates of 0.01, 0.1, and 0.5% ps−1 to evaluate the interfacial strength and interface failure mechanism. Results show that the polycrystalline Cu models always exhibits a lower degree of stress and shows a great ductile character. The existence of twin grain boundaries makes Cu layer more stable, and their failure processes are dominated by stair-rod type dislocations with a Burgers vector of 1/6 [110] instead of Shockley dislocations with a Burgers vector of 1/6 [112], which induce their interface models fail in Cu3Sn layer near the interface. The strain rate dependence mechanical character of both interface and grains would be the main reason of phenomenon for the difference failure character affected by grain structure and strain rate.

In Fe-Si alloy systems, the Fe-6.5wt%Si alloy shows low iron core losses and near-zero magnetostriction, thus having great potential for high-frequency applications. In this study, an Fe-6.5wt%Si alloy hot band was subjected to a moderate warm rolling with a thickness reduction of 40%, and then annealed at different temperatures. The recrystallization behavior was investigated using the EBSD technique. After the moderate warm rolling, the initial gradient structure of the hot band is inherited, leading to gradient recrystallization behaviors during the further annealing process. The sheet surface first densely nucleates and forms strong //ND and {221} textures. However, the //ND and {221} grains have fewer high-mobility and high-energy (20–45°) boundaries than the other oriented matrix grains, leading to insufficient growth advantages. In the center region, the recrystallization is slow, but the nuclei usually have larger sizes. The inheritance of the //ND (θ-fiber) texture from the initial hot band appears. Some θ-fiber grains, which have easy-magnetized axes lying in the sheet plane, preferentially nucleate in the strong α-fiber textured matrices and form a strong θ-fiber recrystallization texture in the center region.

The shear-compression deformation of GH4169 superalloy at 1000–1200 °C and 0.01–1 s−1 was investigated by physical and numerical simulation based on a specific shear-compression sample (SCS). OM, EBSD, and TEM analysis revealed the three typical regions in SCS. Dynamic recrystallization (DRX) preferred to occur in the slot region due to the strain concentration, where the Mises equivalent strain was about 4–6 times higher than the pre-set ones. Mixed grains were observed in the transition region because of insufficient deformation. In contrast, equiaxial grains were preserved in the cylindrical region with negligible deformation. Experimental stress decreased with the increase of temperature and decrease of strain rate. The maximum stress was 180 MPa, which was only 30% of that under single compression deformation. Furthermore, four DRX mechanisms were observed in GH4169. Discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX) were the dominant and auxiliary mechanisms, respectively. Twinning dynamic recrystallization (TDRX) occurred in the annealing twins with a fast nucleation rate, and the intersected nano-twins provided favorable nucleation sites for DRX. Lastly, secondary dynamic recrystallization (SDRX) with unique nucleation mechanism of triangularly intersecting subgrain boundaries emerged in SCS, which nucleated in the DRX grains and further refined the microstructure of GH4169.

The development of advanced electronic devices leads to highly miniaturized interconnect circuits (ICs), which significantly increases the electromigration (EM) phenomenon of solder and circuits due to higher current density. The electromigration of solder joints under high current density has become a severe reliability concern in terms of microelectronic product reliability. The microstructure of the solder plays an important role in the electromigration induced degradation. In this study, Sn-3.0Ag-0.5Cu solder bumps with Ni/Au under bump metallization (UBM) layer were fabricated and electromigration acceleration tests were conducted under current density of 1.4 × 104 A/cm2 and 120 °C to investigate the effect of grain structure and Ni/Au-UBM layer on EM-induced failure. Grain structures of solder bumps were determined by utilizing the Electron Backscatter Diffraction (EBSD) technique, and single-crystal solder, single-crystal dominated solder, and polycrystalline solder are observed in different test samples. According to the Scanning Electron Microscope (SEM) images, it is observed that the Ni/Au-UBM layer of the Cu pad can inhibit atom diffusion between solder bump and Cu pad, which reduces the consumption of Cu pad but causes a large void and crack at the interface. The EM lifetime of single crystal solder bumps is lower than that of polycrystalline solder bumps when the c-axis of single crystal solder bumps is perpendicular to the electron flow direction. Additionally, the single crystal structure will increase the brittleness of the solder bump, and cracks are easily generated and expanded under the stress caused by the mismatch of thermal expansion coefficients between the solder bump and Ni/Au-UBM layer near Cu pad. Polycrystalline solder bumps with a higher misorientation angle (15–55°) have a higher atom diffusion rate, which will result in the acceleration of the EM-induced failure.

Based on conventional hot rolling processes and strip casting processes, Cu precipitation strengthening is used to improve the strength of non-oriented silicon steel in order to meet the requirements of high-speed driving motors of electric vehicles. Microstructure evolution was studied, and the effects of Cu precipitates on magnetic and mechanical properties are discussed. Compared with conventional processes, non-oriented silicon steel prepared by strip casting exhibited advantages with regard to microstructure optimization with coarse grain and {100} texture. Two-stage rolling processes were more beneficial for uniform microstructure, coarse grains and improved texture. The high magnetic induction B50 of 1.762 T and low core losses with P1.5/50, P1.0/400 and P1.0/1000 of 1.93, 11.63 and 44.87 W/kg, respectively, were obtained in 0.20 mm sheets in strip casting. Cu precipitates significantly improved yield strength over ~120 MPa without deteriorating magnetic properties both in conventional process and strip casting. In the peak stage aged at 550 °C for 120 min, Cu precipitates retained bcc structure and were coherent with the matrix, and the yield strength of the 0.20 mm sheet was as high as 501 MPa in strip casting. The main mechanism of precipitation strengthening was attributed to coherency strengthening and modulus strengthening. The results indicated that balanced magnetic and mechanical properties can be achieved in thin-gauge non-oriented silicon steel with Cu addition in strip casting.

Objectives. Unknown onset stroke (UOS) is usually excluded from intravenous thrombolysis concerning the unclear symptom onset time. Attempts have been done to use thrombolytic therapy in these patients. The current meta-analysis was done to examine the efficacy and safety of intravenous thrombolysis in UOS. Methods. PubMed, Web of Science, and Cochrane Library were searched for studies comparing thrombolysis with conservative therapy among UOSs. Data of good outcome (mRS, 0-2), mortality, and intracerebral hemorrhage (ICH) and symptomatic ICH (sICH) were extracted and analyzed using the Revman 5.2 software. Results. In total, 8 studies with 1271 subjects (542 with thrombolysis and 729 with conservative therapy) were included in this meta-analysis. The data showed that patients receiving thrombolysis had a higher incidence of 90-day good outcome (P=0.0005) than conservative therapy. The comparison of discharge (P=0.89) and 90-day mortality (P=0.10) in both groups did not find any significances. The incidences of ICH (P=0.42) and sICH (P=0.06) were relatively comparable between the two therapies. Conclusions. Intravenous thrombolysis is a better choice for UOS patients for its efficacy and safety. In addition, pretreatment imaging assessment is beneficial for improving the efficacy of thrombolytic therapy. However, it needs more supporting evidences for clinical use in the future.

Glass forming ability (GFA) is one of the key factors hindering the application of bulk metallic glasses (BMGs). Microalloying has shown beneficial effects on GFA. However, the mechanism is still unclear. A new guidance via clusters was applied to understand and quickly choose beneficial microalloying elements for enhancing GFA which might help build a foundation for further quantitative analysis of minor alloying via clusters. Under the guidance, a series of beneficial microalloying elements could be quickly discovered, verified and understood. The results show that the beneficial microalloying elements for enhancing GFA should be chosen under the condition of bringing in new types of topologically efficiently packed clusters.

The Nb-bearing grain-oriented silicon steel sheets were produced by conventional route and novel twin-roll casting route, respectively. The microstructure, texture and precipitate evolution were comparatively investigated by using electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The findings revealed that the precipitation behavior and the texture evolution were totally different between the two processing routes. In the conventional route, a great number of nanoscale niobium nitride particles (NbN), which acted as mainly grain growth inhibitors were precipitated during hot rolling, while in the twin-roll casting route, due to the rapid solidification, the precipitation of NbN were suppressed and a new type Nb-bearing precipitate enriched with sulfur element was observed in the as-cast strip. Besides, the primary recrystallized texture of conventional specimens was characterized by strong γ-fiber with a peak at {111} , together with very few Goss components. While in the case of twin-roll casting specimens, the strongest primary recrystallized texture was {111} texture and the area fraction of Goss component was much higher than that of conventional specimens. After final high temperature annealing, complete secondary recrystallization was obtained in twin-roll casting specimens and the magnetic induction of B8 was 0.1 T higher than that of conventional specimens.

Grain-oriented silicon steels were produced by the shortest processing route involving twin-roll strip casting, two-stage cold rolling with intermediate annealing, and simulated continuous annealing. The secondary recrystallization behavior of grain-oriented silicon steels under different inhibition conditions was in-situ observed by combining the confocal laser scanning microscopy (CLSM) and electron backscattered diffraction (EBSD) techniques. The results revealed that the optimal temperature of secondary recrystallization showed a proportional relationship with the Zenner pinning force. In the case of weak pinning force, the abnormal grain growth occurred quickly at ~1050 °C. The corresponding growth rates were in the range of 60–1400 μm/min and decreased gradually as the secondary recrystallization proceeded. In the case of strong pinning force, the incubation time and onset temperature of the secondary recrystallization was significantly increased, but the total time of the secondary recrystallization was obviously shortened from 685 s to 479 s, and the final magnetic induction of B8 was increased from 1.7 T to 1.85 T. After the secondary annealing, some island grains and coarse primary grains were retained. The formation of island grain was related to the low migration of grain boundaries. The findings of coarse γ- grains indicated that the primary grain size also played a crucial role during secondary recrystallization, apart from the primary recrystallized texture, which attracted more attention previously.