摘要：Electrical steel sheets with 6.5%(mas fraction) Si with good shapes and superior magnetic inductions were successfully produced by a specially designed processing route including ingot casting, hot rolling and warm rolling both with interpass thermal treatment, and final annealing. The sheets were of 0.2 mm and 0.3 mm thick over 140 mm width. A detailed study of the microstructural and textural evolutions from the hot rolling to annealing was carried out by optical microscopy, X-ray diffraction and electron backscattered diffraction. The hot rolled sheet characterized by near-equiaxed grains was dominated by the mixture of //ND fiber(λ-fiber), //RD fiber(α-fiber) and //ND fiber(γ-fiber) textures owing to the partial recrystallization and strain induced boundary migration(SIBM) during the hot rolling interpass thermal treatment. The static recovery and SIBM during the warm rolling interpass thermal treatment result in large and elongated warm rolling grains. The warm rolling texture is dominated by obvious λ, Goss and strong γ-fiber textures. The application of the interpass thermal treatment during hot and warm rolling significantly enhances the impact of SIBM during annealing, which is responsible for the formation of the moderate λ-fiber, some near-λ fiber texture components and the obviously weakened γ-fiber texture in the annealed sheet, leading to a higher magnetic induction compared to the commercially produced 6.5% Si steel by chemical vapor deposition(CVD).

摘要：The mechanical properties dependence on the microstructure was reviewed and analyzed,and the ultrafine grained duplex microstructure of BCC matrix and large fractioned austenite was given as one of the optimum structures to develop the third generation steel with high strength and high *** medium-Mn steels with different carbon contents processed by austenite reverted transformation(ART-annealing) were studied thoroughly to fabricate the ultrafine duplex steels with large fractioned *** lamellar typed ultrafine structure,the granular typed ultrafine duplex structure and the corresponding mechanical properties of the medium-Mn steels processed by ART-annealing were demonstrated in this *** was revealed that the duplex structure with large fraction of austenite and ultrafine grain structure is capable of producing steels with excellent combination of strength and ductility,i.e.,Rm A about 30-50 GPa%,which is about two times of that of the conventional automobile steels and close to that of the TWIP *** was concluded that the ART-annealing of the medium-Mn steels would be at least one of the promising ways to fabricate the third generation automobile steels in the near future.

摘要：The microstructural evolutions of the cold rolled Fe-0.1C-5Mn steel during intercritical annealing were ex- amined using combined advanced techniques. It was demonstrated that intercritical annealing results in an ultrafine granular ferrite and austenite duplex structure in cold rolled 0.1C-5Mn steel. The strong partitioning of manganese and carbon elements from ferrite to austenite was found during intercritical annealing by scanning transmission elec- tron microscopy （STEM） and X-ray diffraction （XRD）. Strong effects of boundary characters on the austenite for- mation were indicated by austenite fast nucleation and growth in the high angle boundaries but sluggish nucleation and growth in the low angle boundaries. The ultrafine grained duplex structure in 0.1C-5Mn was resulted from the the sluggish Mn-diffusion and the extra high Gibbs free energy of ferrite phase. Based on the analysis of the micro- structure evolution, it was pointed out that the intercritical annealing of the medium Mn steels could be applied to fabricate an ultrafine duplex grained microstructure, which would be a promising approach to develop the 3rd genera- tion austomobile steels with excellent combination of strength and ductility.

摘要：After summarizing the relevant researches on the medium Mn steels in references, two new targets on the tensile properties have been defined. One is that both transformation-induced（TRIP） and twinninginduced plasticity（TWIP） could be realized for the steel with a relatively low Mn content, which exhibits the similar tensile properties to the classical TWIP steels with higher Mn content. The other is to achieve ultrahigh ultimate tensile strength（〉1.5 GPa） without sacrificing formability. To achieve these goals,new designing strategies was put forward for compositions and the processing route. In particular, warm rolling was employed instead of the usual hot/cold rolling process because the former can produce a mixture of retained austenite grains with different morphologies and sizes via the partial recrystallization. Consequently, the retained austenite grains have a wide range of mechanic stability so that they can transform to martensite gradually during deformation, leading to enhanced TRIP effect and then improved mechanic properties. Finally, it is succeeded in manufacturing these targeted medium Mn steels in laboratory, some of them even exhibit better tensile properties than our expectation.

摘要：A systemic investigation was done on the chemistry and crystal structure of boundary phases in sintered Ce9Nd21FebalB1 （wt%） magnets. Ce2Fe14B is believed to be more soluble in the rare-earth （RE）-rich liquid phase during the sintering process. Thus, the grain size and oxygen content were controlled via low-temperature sintering, resulting in high coercivity and maximum energy products. In addition, Ce formed massive agglomerations at the triple-point junctions, as confirmed by elemental mapping results. Transmission electron micros- copy （TEM） images indicated the presence of （Ce,Nd）Ox phases at grain boundaries. By controlling the composition and optimizing the preparation process, we successfully obtained Ce9Nd21FebalBx sintered magnets; the prepared magnets exhibited a residual induction, coerciv- ity, and energy product of 1.353 T, 759 kA/m, and 342 kJ/m3, respectively.

摘要：Hot roll bonding was carried out between commercially pure titanium TA2 and high-strength low-alloy steel Q390 using pure Nb or Mo interlayer at 950 ~C with a total reduction ratio of 86.7%. Interfacial microstructure and bonding properties of titanium clad steel plates were investigated by electron microscopy and mechanical tests. The results showed β-Ti, TiC and Fe2Ti reaction phases were generated at Ti/steel interface for the clad plates with no interlayer. Inserting Nb or Mo interlayer can effectively suppress the formation of brittle phases, while the weak bonding joint transferred to Nb/steel or Mo/steel interface. And some micro-voids were found at the interface of Nb/steel and Mo/steel. The improved shear strength of clad plates with Nb interlayer might be attributed to the elimination of brittle phases at bonding interface. The small size and little quantities of the micro-voids at Nb/steel interface had a relatively weak effect on shear strength. However, the large number and big size of micro-voids were responsible for the degradation of shear strength for the clad plates with Mo interlayer.

摘要：The fundamental idea of materials genome initiative is the integration of computing platform,experimental platform,and data platform to speed up the material innovation hence reduce time and *** paper describes the basic concept of building an integrated computational platform and data platform for material innovation from the perspective of high-throughput simulation and materials knowledge *** material data platform that can integrate material database,heterogeneous material data,various scripts,and open-source material simulation code together is particularly *** metallic materials as an example,a brief introduction to metallic materials data management is given,and how to manage the semi-structure and unstructured iron and steel material data is also presented.

摘要：The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanical *** orthogonal experimental design was used to study the influence of plasma-MIG welding parameters on the aluminum weld *** mixed orthogonal matrix L16(4 4×2 3) and analysis of variance (ANOVA)technique were employed to optimize the welding *** experimental results indicate that the effect of plasma gas flow rate is dominant,the secondary factors are MIG welding voltage,welding speed,wire feed rate and plasma current in *** experiments were conducted under optimum conditions and there was almost no porosity in the welded joints,thus good mechanical performance joints were obtained.

摘要：Computational thermodynamics,known as CALPHAD method when dawned in 1950s,aimed at coupling phase diagrams with thermochemistry by computational *** eventually evolves toward kinetic simulations integrated with thermodynamic calculations,i.e.,computational kinetics,including diffusion-controlled phase transformation,precipitation simulation,and phasefield *** the meantime,thermodynamic,mobility,and physical property databases for multi-component and multi-phase materials,served as basic knowledge for materials design,are critically evaluated by CALPHAD approach combining key experiments,first-principles calculations,statistic methods,and empirical *** combination of these computational techniques with their conjugated databases makes it possible to simulate phase transformations and predict the microstructure evolution in real materials in a foreseeable *** links to microand macro-scale simulations lead to a multi-scale computational framework,and aid the search for the quantitativerelations among chemistry,process,microstructures,and materials properties in order to accelerate materials development and *** is a new route of materials and process design pursued by Integrated Computational Materials Engineering(ICME)and Materials Genome Initiative(MGI).This article presents a review on the basic theories and applications,the state of the art and perspective of computational thermodynamics and kinetics.

摘要：Li4Ti5O12（LTO）/carbon nanotubes（CNTs） composite material is synthesized based on a solid-state method by sand-milling, spray-drying and calcining at 850 8C under N2 flow. The LTO/CNTs samples with1 wt% and 3 wt% weight ratio of CNTs addition and the pristine LTO sample are prepared. The rate performance and the thermal stability of these samples are investigated based on Li Mn2O4（LMO）/LTO full-cell. The results show that the weight ratio of CNTs addition has distinct effect on LTO *** composite materials of LTO composited CNTs have better performance at high-rate due to the intercalation enhancement by conductive network of CNTs. At second, the overcharging temperature response of the cell＇s surface with 1 wt% CNTs addition is the lowest. The particle size distribution is measured and the most uniform particles are obtained with 1 wt% CNTs addition. This trend could explain that the medium quantity of CNTs is optimal to improve the heat and mass transfer and prevent the problems of crystallite growing interference and aggregation during the calcination process.