This study investigated the influence of solution-aging treatment (SAT) on the hydrogen embrittlement (HE) of selective laser melted 17-4 PH stainless steel. It was found that the as-printed steel exhibits a martensite/ austenite duplex phase microstructure with fine grains, which provides abundant grain boundaries/phase boundaries serving as hydrogen traps, thereby exhibiting a low hydrogen diffusivity. During SAT process, complex microstructural evolution such as grain coarsening, precipitation of nano-sized NbC/s-Cu particles, and gamma-*alpha ' phase transformation occurred in the steel. Collectively, these evolutions induced the hydrogen diffusion coefficient increasing first and then decreasing with the rise of solution temperature. Quantitively analysis revealed that the impact of austenite on hydrogen diffusion exceeds other microstructural factors. The mechanical test results show that SAT plays dual impacts on the hydrogen-assisted fracture, causing HE susceptibility to show a complex change of first increasing and then decreasing with increasing solution temperature. The advantage lies in that the precipitation of the nano-phase not only inhibits hydrogen-assisted intergranular cracking by serving as deep hydrogen traps, but also hinders dislocation movement to inhibits hydrogenenhanced localized plasticity. Conversely, the disadvantage lies in that the increase in martensite content, grain coarsening, and the gradual increase in the fraction of E3 boundary in the martensite phase collectively reduce cracking resistance, exacerbating HE fractures.

The growing demand for high-strength and low-core-loss soft magnetic materials in high-efficiency energy conversion devices necessitates the development of novel alloys that combine excellent mechanical and soft magnetic properties. This work investigated the effect of Ta content on the microstructure and properties of as-cast (Fe7Co6Ni6)93-xTaxAl7 (x = 3, 5, 7) multiprincipal element alloys (MPEAs). Microstructural characterization and mechanical and magnetic testing were conducted using scanning transmission electron microscopy (STEM), tensile testing, and vibrating sample magnetometry (VSM). The alloys featured an FCC matrix, in which Ta addition led to the precipitation of a Ta-rich Laves phase and significant grain refinement. The Ta5 alloy demonstrated an optimal balance of properties, with a yield strength approaching 992 MPa, an elongation of 10%, a saturation magnetization (Ms) of 94.16 emu/g, and a coercivity of 6.69 Oe, indicating a good balance of strength, ductility, and soft magnetic performance. An appropriate amount of Ta enhanced strength via precipitation and grain-boundary strengthening, while the Ms showed only a moderate reduction.

Grain-oriented silicon steel stands as the cornerstone soft-magnetic material for ultra-high voltage transformers and high-efficiency energy-saving distribution transformers. Its outstanding magnetic properties， characterized by high magnetic flux density and low core loss， are mainly ascribed to the well - defined Goss texture in the final microstructure. Nevertheless， the mechanism governing the abnormal grain growth （AGG） of Goss grains during annealing is exceedingly intricate and remains incompletely understood， posing a significant bottleneck that impedes the further enhancement of its magnetic performance.This review comprehensively summarizes the nucleation and growth behaviors of Goss grains throughout the entire manufacturing process， spanning from hot rolling to high-temperature annealing， and delineates the optimization strategies for key production processes. It also systematically synthesizes the typical features of abnormally grown Goss grains， such as grain size， orientation deviation， and internal island grains， with a particular emphasis on analyzing how these features influence magnetic properties and the corresponding regulatory approaches. Moreover， a thorough review is conducted on various theoretical models proposed for the AGG mechanism of Goss grains， covering their fundamental principles， applicability， and limitations. Finally， key research directions for future investigations into the Goss AGG mechanism are proposed， aiming to offer a valuable reference for promoting the development of high-performance grain-oriented silicon steel.

Non-oriented silicon steels with both excellent magnetic properties and high strength are essential for the drive motors of new energy vehicles. However, achieving a balance between strength and magnetic properties is a challenging task. This study successfully developed non-oriented silicon steel that met these demanding requirements by utilizing the coherent nano-Cu-rich phases precipitated during aging. In the current investigation, the evolution of precipitation during the aging process of Cu-alloyed non-oriented silicon steel is revealed as: BCC Cu-rich cluster (Fe:Cu > 1) -> B2 FeCu cluster (Fe:Cu approaches 1) -> BCC Cu cluster (Fe:Cu < 1) -> Twinned 9R Cu -> Detwinned 9R Cu. Notably, the 9R Cu precipitated in the later stage of aging was coarse and incoherent with the matrix, offering minimal strengthening benefits while considerably deteriorated the magnetic properties. Conversely, the other three phases that formed in the early stage of aging were fine, dispersed, and coherent with the matrix, effectively enhancing the yield strength of the steel with minimal negative impact on its magnetic properties. The total increment of yield strength attributed to BCC Cu-rich clusters, B2 FeCu clusters, and BCC Cu clusters were 207, 304, and 374 MPa, respectively. The strengthening mechanism operated primarily through the cutting mechanism, which was dominated by the modulus difference strengthening and coherent strain strengthening. Moreover, a unique ordered strengthening of approximately 207 MPa arose from the ordered B2 FeCu clusters. Thus, the steel aged for 3-30 min with the precipitation of B2 FeCu clusters and BCC Cu clusters exhibited the most favorable overall performance with a yield strength of 750-800 MPa, P-1.0/400 of 16.3-18.3 W kg(-1), and B-5000 of 1.641-1.656 T. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Hydrogen embrittlement (HE) is one of the key issues limiting the application of laser-powder bed fusion (LPBF) 18Ni-300 maraging steels. This investigation compares the impact of solution-aging treatment parameter, i.e., solution + conventional aging treatment (SCAT, 820 degrees C x 1h + 490 degrees C x 6h), and a solution + long-term lowtemperature aging (SLAT, 820 degrees C x 1h + 390 degrees C x 9h) on the HE of LPBF 18Ni-300 steel. The results indicate that although these two heat-treatment processes lead to decomposition of cellular structures and coarsen of grains, they also form a substantial volume of precipitates that serve as hydrogen traps, thereby increasing the overall hydrogen trap density and reducing hydrogen diffusively. Compared with SCAT steel, despite the precipitates formed in the SLAT steel transform to omega phase with a smaller volume fraction, but its grain size is smaller, thereby exhibiting slightly lower hydrogen diffusion coefficient. Crack observation indicates that after solution-aging treatment, the possibility of intergranular cracking increases, the promotion of dislocation multiplication by hydrogen is suppressed, and the contribution of the hydrogen-enhanced decohesion mechanism to HE fracture increased. The slow strain rate tests further reveal solution-aging reduces HE resistance, which primarily caused by the vanishment of cellular structures, grain coarsening, the additional reversible Htraps provided by precipitates, and the enhancement in strength. In comparison to SLAT, the steel subjected to SCAT demonstrates a marginal rise in austenite content and a further optimization in the proportion of Sigma 3/Sigma 11 grain boundaries, consequently displaying a reduced HE susceptibility.

A grain-oriented silicon steel was normalized with a novel high magnetic field using one-stage cooling process. The effect of high-magnetic-field normalizing on the microstructures and textures was studied with a hot-rolled sheet as initial material. It was found that recrystallization and the grain growth were enhanced owing to the external magnetic field driving force. The angle between Goss orientation and magnetic field direction was small, resulting in a high nucleation rate of Goss grains, and hence, the intensity of Goss texture was increased and the deviation angle of Goss grains was reduced after high-magnetic-field normalizing. Furthermore, the migration of dislocation was promoted with an external magnetic field driving force and the density of dislocation decreased, reducing the proportion of low-angle grain boundaries around the Goss grains. The enhancement of recrystallization process and grain growth increased the proportion of high-energy grain boundaries and high-angle grain boundaries, providing a favorable condition for the growth of Goss grains.

Drive motors for new energy vehicles require nonoriented silicon steel with high strength and excellent magnetic properties, which are always difficult to balance. In this study, the effects of Cu content on the precipitates, microstructure, and properties of nonoriented silicon steel are investigated. The results show that a dispersed and coherent nanoscale B2 Cu‐rich precipitates are formed when Cu addition is 0.91 wt%, while ε‐Cu precipitates with large size and low number density are formed with higher Cu addition. The nanoscale B2 Cu‐rich precipitates afford a higher precipitation strengthening contribution than the larger ε‐Cu precipitates via cutting mechanism. Concurrently, the nanoscale B2 Cu‐rich precipitates nominally affect the iron loss deterioration. With increasing Cu content, the average grain size decreased, while the favorableλtexture diminished, and the unfavorableγtexture increased. With the combined effect of the grain size, texture, and precipitates, the iron loss increased first slightly and then significantly with further Cu addition, whereas the magnetic induction gradually decreased. The comprehensive properties of the steel are optimal when Cu addition was 0.91 wt%, which yielded a yield strength of 571.2 MPa, an iron loss P1.0/400of 20.05 W kg−1, and a magnetic induction B5000of 1.621 T.

High performance e-motors require a continuous enhancement of physical and mechanical properties for non-oriented electrical steel (NOES). However, the optimization of mechanical and magnetic properties simultaneously during NOES processing is extremely challenging where both properties directly influenced by alloy grain size, crystallographic texture, and dislocation density. In the current investigation, recrystallization annealing cycles were employed to modify the microstructure with the aim of balance magnetic and mechanical properties of NOES concurrently. The results showed that with increasing annealing temperatures, the degree of recrystallization and grain size increased, while the dislocation density reduced considerably at the early stage of recrystallization. Meanwhile, the values of texture parameter A_overall^* (which is a function of overall individual grain orientations and their alignments with easy magnetization directions) were increased. It was evident that the magnetic properties were significantly improved, however the alloy strength was reduced with increasing annealing temperatures. Here, the correlation between magnetic properties as well as alloy strength on grain size, texture, and dislocation density were determined. From crystallographic texture intensity and measured properties quantitative analyses it was concluded that grain size was the predominant factor in balancing the mechanical and magnetic properties of the studied steel. Furthermore, the optimal comprehensive properties (both magnetic and mechanical) were achieved by annealing at 800 °C, which yielded a magnetic induction B5000 of 1.616 T, a high-frequency iron loss P1.0/400 of 22.43 W/kg, and a yield strength of 527 MPa.

The challenge in high-strength non-oriented silicon steel is the synergistic enhancement of both strength and magnetic properties, which are both significantly influenced by microstructure and texture of the steel. To address this, a novel high magnetic field annealing was employed to modify the microstructure and texture of the steel, aiming for a concurrently optimization of these properties. The results indicated that both the iron loss and strength decreased with increasing annealing temperature, whereas the magnetic induction intensity increased firstly and then decreased. The application of a high magnetic field meaningfully enhanced the magnetic properties of non-oriented silicon steel, whereas the strength of the steel was significantly decrease at 750 degrees C, but this decrease was reduced at higher temperature. The application of magnetic field reduced the Gibbs free energy of the system during the recrystallization process resulting in a facilitation of recrystallization. During lowtemperature annealing (750-800 degrees C) in the high magnetic field, the dislocation density decreased, and internal stress was reduced, leading to a significant reduction in hysteresis loss and an improvement in magnetic properties. However, the reduction in dislocation density resulted in a substantial deterioration of strength at low temperature. With increasing annealing temperature, the enhanced grain growth with the application of magnetic field lead to an increase in magnetic induction intensity, whereas the grain boundary strengthening contribution decreased, resulting in a decrease in strength. Furthermore, the optimal comprehensive properties were achieved by annealing at 850 degrees C with a high magnetic field, which yielded a magnetic induction intensity B5000 of 1.679 T, a high-frequency iron loss P-1.0/400 of 21.44 W/Kg, and a yield strength of 508 MPa, are wellsuited for utilization in the drive motors of new energy vehicles.

Nonoriented electrical steel for new energy vehicles should have high strength and excellent magnetic properties simultaneously. However, it is challenging to optimize mechanical and magnetic properties simultaneously during nonoriented electrical steel processing. This article prepares nonoriented electrical steel with high strength and excellent magnetic properties by Cu–Ni alloying, and the evolution of properties of Cu–Ni‐alloyed nonoriented electrical steel during aging and underlining mechanisms is studied. The optimal strength is achieved when aging for 10 min with a yield strength of 773 MPa, where the magnetic induction intensity (B50) is 1.66 T, and the iron loss (P1.0/400) is 18.07 W Kg−1. The optimal strength is attributed to the Cu–Ni recombination, which induces a rapid precipitation of numerous small‐sized Cu‐rich phases within a short period. Besides, the main strengthening mechanisms of the small‐size Cu‐rich phases are modulus strengthening and ordered strengthening. Furthermore, the small‐size Cu‐rich phases with B2 and body‐centered cubic structure in the earlier aging period do not deteriorate the magnetic properties of the steel. Nevertheless, in the late aging period, due to the coarsening of the precipitated Cu‐rich phase with face‐centered cubic structure and the abnormal growth of some grains, the eddy current loss increases, leading to worsen magnetic properties.

The effects of aging rolling temperature （150， 200， 250， 300 ℃） on microstructure ， texture and magnetic properties of low-temperature grain-oriented silicon steel were studied by aging rolling experiment at different temperatures for 5 min. The results show that the aging rolling temperatures has no obvious effect on the microstructure morphology of cold rolling and primary recrystallization of low-temperature grain-oriented silicon steel. However， the contents of ｛111｝<112> and Goss in the primary recrystallization microstructure increased and then decreased with the increase of aging rolling temperature， and with the highest contents at 200 ℃ for ｛111｝<112> texture， while at 250 ℃ for Goss texture. And the proportion of primary recrystallization texture of ｛411｝<148> and ｛100｝<012> is relatively low. The increase of Goss and ｛111｝<112> texture and the decrease of ｛100｝<012> texture in the primary recrystallization microstructure resulted in perfect secondary recrystallization of the sample during high temperature annealing. After high temperature annealing， there were fewer fine grains and island grains， and the final sheets had excellent magnetic properties.

Effect of aging rolling on the microstructure,texture and magnetic properties of the low-temperature oriented silicon steel was studied by conducting aging rolling tests at 250 ℃ for different time using a single cold rolling method.The results indicate that the aging rolling has no significant effect on the cold rolling and primary recrystallization microstructure of low-temperature oriented silicon steel,but it can significantly improve the primary recrystallization texture.The contents of favorable Goss and { 111 }<112>textures in the primary recrystallization microstructure increase first and then decrease with the increase of aging rolling time,reaching the maximum value at 5 min.An increase in favorable texture content can improve the secondary recrystallization microstructure and enhance the magnetic properties of the final sheet.The magnetic induction intensity of the final sheet increases first and then decreases with the prolongation of aging rolling time,and the iron loss shows the opposite trend.When the aging rolling time is 3-7 min,the final sheet has excellent magnetic properties.

The variation rule of deformation structure and magnetic properties of high strength non -oriented electrical steel with cold rolling were studied by field emission scanning electron microscopy (SEM+ EBSD ), rapid temperature tube furnace and AC magnetic properties measuring instrument. The results show that the rough strips with a large number of substructures and smooth strips with a small amount of deformation are formed in cold -rolled high strength non -oriented electrical steel. The rough strip has a gamma orientation , mainly {111 }< 110 >, and the smooth strip has a {112 }< 110 > and {001 }< 110 > orientation. In the rough strips , there are a lot of shear bands with width of about 2-3 mu m , which show an angle of 20 degrees -35 degrees to the rolling direction. And the quantity increases gradually with the increase of the reduction rate. There is a certain misorientation between the shear band and the matrix. With the increase of the reduction rate , the shear band gradually changes from {111 } < 110 > to {223 }< 110 >, and the misorientation between the shear band and the matrix gradually increases. After annealing , the texture of Goss and {111 } increases , while the texture of {001 } decreases. The rolling direction magnetic induction intensity increases , the transverse magnetic induction intensity decreases , the magnetic anisotropy is significant , and the iron loss decreases.

本文针对6.5%Si高硅钢的室温脆性难以轧制问题,采用普通硅钢热轧板(≤3%Si)对高硅钢(6%～8%Si)钢坯进行包套,通过热轧、温轧及高温退火制备0.3 mm厚高硅钢带材.通过研究发现,包套高硅钢热轧板在室温和280℃温度区间发生了较为明显的脆性-韧性转变,在280℃拉伸时延伸率显著增大,断口形貌呈现出大量韧窝,表现为塑性断裂.根据实时监测的工艺参数可知,包套6.5%Si高硅钢热轧板在550～600℃温轧时的平均轧制力与板厚、辊缝、材料硬化程度及开轧温度等因素相关,压下率随着厚度的减薄先增大而后减小,减小的原因与轧制负荷趋于饱和及轧制厚度接近目标厚度有关.温轧成品板的包覆层与中间层之比为1/5,0.3 mm厚温轧板经高温退火后,制备出成品板磁性能优异,其高频铁损P0.2/10k为78.8 W/kg,明显低于普通的3%Si硅钢.

The substitution behavior of Cu doped into Fe3Si and its effect on the electronic structure and mechanical properties of Fe3Si were investigated using first principles plane-wave pseudopotential method based on density functional theory. Alloys with dopant Cu taking position of atoms Fe(I), Fe (II), and Si were labeled as Fe11CuSi4(I), Fe11CuSi4(II), and Fe12Si3Cu, respectively. The calculated formation enthalpy and cohesive energy of the three compounds and Fe3Si alloy were all negative, indicating their thermodynamic stability. However, the atomic fraction of dopant Cu substituting on Si atom was approximately zero, implying that the formation of Fe12Si3Cu is challenging. According to the analysis results of differential charge density and Bader charge, the covalent bond was weakened after Cu doping, while the ionic bond strength was in the order of Fe11CuSi4(I) > Fe3Si > Fe11CuSi4(II) > Fe12Si3Cu, which also indicated that the Fe12Si3Cu is less stable than the other three compounds. These results suggested that the dopant Cu atom preferred to substitute Fe atom, particularly Fe(I), but hardly substitute the Si atom. In order to gain a better understanding of the effect of Cu doping on the mechanical properties of Fe3Si compound, the antiphase boundary energy (ABPE) and elastic constants of Fe3Si, Fe11CuSi4(I), and Fe11CuSi4(II) were further calculated. The value of APBE was decreased, whereas the plasticity of Fe3Si compound is increased with the substitution of Fe atoms by the Cu dopant. The enhanced plasticity of Fe3Si alloy by Cu doping results from the dominant influence of the reduced APBE and weakened covalent bonds over the effect of reduction in ionic bonding.

In view of the brittleness and difficulty in rolling of 6.5% Si high silicon steel at room temperature， ordinary silicon steel hot rolled plate （≤3%Si） is used to cover the high silicon steel （6%-8%Si） billet， and produce 0.3 mm thickness high silicon steel strip by hot rolling， warm rolling and high temperature annealing. It is found that the hot-rolled high silicon steel by pack rolling has a brittle-ductile transition in the range of room temperature and 280 ℃， the elongation increases significantly at 280 ℃， and the fracture morphology exhibits a large number of toughness nests， manifested as plastic fracture. According to the real-time monitoring of the process parameters， it can be seen that the average rolling force of the pack-hot-rolled 6.5% high silicon steel during warm rolling at 550-600 ℃ is related to the plate thickness， roller gap， material hardening degree， rolling temperature and other factors. The reduction rate first increases and then decreases with the thickness reduction. The reason for the reduction is related to the saturation of rolling load and the proximity of rolling thickness to the target thickness. The ratio of the cladding layer to the core layer of the warm-rolled-finished plate is 1/5. Warm rolled plate with a thickness of 0.3 mm was annealed at high temperature， and the high-frequency iron loss P0.2/10k of finished plate is 78.8 W/kg， presenting excellent magnetic properties， which is significantly lower than that of the ordinary silicon steel with 3% Si.

A bottleneck in the development of high-strength non-oriented silicon steels for drive motors of new energy vehicles is the balance of strength and magnetic properties. This paper successfully tackled this problem through the optimization of thickness reduction for hot and cold rolling and the formation of coherent precipitates using a Cu-alloyed non-oriented silicon steel. More specifically, a thickness reduction of 96% in the course of hot rolling promoted the homogenization of microstructure during the following normalization treatment. Subsequently, a deformation degree of 80% during cold rolling ensured the inheritance of the uniform microstructure and inhibited the abnormal growth of recrystallized grains during annealing, thereby suppressing the iron loss to a value as low as 15.6 W/kg. At the meantime, this combined process promoted the inheritance of A.-fibers and the formation of {114}( 481) texture in the annealed sheet, improving the magnetic induction intensity B50 to 1.606 T. In addition, under the joint effect of a variety of strengthening mechanisms, the yield strength of this annealed sheet reached 668 MPa. A pronounced increase in strength, about 207 MPa, was derived from precipitation hardening by the great difference in the modulus between coherent Cu-rich clusters and the a-Fe matrix. (c) 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

New energy vehicles can effectively alleviate the severe dependence of the conventional automobile industry on fossil fuels and the environmental problems worldwide. They are an inevitable requirement in the future development of vehicles. As the power core of new energy vehicles, the driving motors should demonstrate excellent magnetic properties to improve energy conversion efficiency and high strength to resist centrifugal forces during high-speed operation. However, the mechanical and magnetic properties of non-oriented silicon steels remain challenging to balance. Therefore, their coordinated control is a key scientific issue in developing driving motors used in new energy vehicles. This study reviews the regulation of the mechanical and magnetic properties of high-strength non-oriented silicon steels. Additionally, the influence of various strengthening methods on the magnetic properties of non-oriented silicon steels is analyzed. Furthermore, this review highlights the future development of coordinated control of the mechanical and magnetic properties of high-strength non-oriented silicon steels. In non-oriented silicon steels, the dislocation density is relatively low, and the grain size is rather large. Thus, the contribution of dislocation and fine-grain strengthening to the yield strength is minimal. Therefore, by combining fine-grain, dislocation, and solid solution strengthening, the best match in the mechanical and magnetic properties of high-strength nonoriented silicon steels can be obtained. Although the precipitation strengthening effect of alloying elements, such as Nb, Ti, V, and Zr, in nonoriented silicon steels is evident, the carbonitrides formed are coarse-sized and irregularly shaped, which considerably deteriorates the magnetic properties of nonoriented silicon steels. During the early stage of aging treatment, the dispersed Cu precipitates with a BCC structure and fairly small grain size, exhibiting a good strengthening effect. Moreover, these Cu precipitates are coherent with the matrix and exhibit little hindering force on the movement of magnetic domains such that they do not deteriorate the magnetic properties of nonoriented silicon steels. Therefore, employing various strengthening methods or finely dispersed nano-coherent precipitates, nonoriented silicon steels with high strength and excellent magnetic properties can be developed for application in driving motors of new energy vehicles, which is an essential requirement for the high-quality development of the new energy vehicle industry.

The optimization of magnetic and mechanical properties by microstructure modification is tremendously challenging for high-grade non-oriented silicon steel. In the current study, the microstructure of cold-rolled high-grade non-oriented silicon steel was modified by recrystallization annealing to achieve high strength and good magnetic properties. The results indicate that recrystallization annealing significantly improved the magnetic properties, while negatively impacting its mechanical properties. At the early stage of annealing (<2 min), recrystallization nucleation occurred in the deformation matrix, leading to a significant decrease in dislocation density. This decrease in dislocation density resulted in a notable reduction in coercivity and hence enhancement in magnetic properties. However, the mechanical properties deteriorated due to the elimination of dislocations. With further increasing the annealing time (>2 min), the recrystallization grains grew within the fully recrystallized matrix. There was a slight decrease in both dislocation density and grain boundary density, leading to a slight decrease in iron loss and yield strength. The magnetic induction intensity of the fully recrystallized annealed sheets was primarily influenced by the recrystallization texture. Thus, the critical annealing time was 2 min to meet the demands of both magnetic and mechanical properties for the studied high-grade non-oriented silicon steel.