Effect of Cutting Techniques on the Structure and Magnetic Properties of a High-grade Non-oriented Electrical Steel

The high grade non-oriented electrical steel sheets containing 3.0%Si were manufacturing processed using different cutting techniques, then they were stress relief annealed（SRA）, the profiles and textures of the cutting edges were compared before and after annealing, and the magnetic properties of these specimens were tested and compared. The experimental results show that the iron loss of the specimen by water jet cutting is the lowest, but the magnetic induction under the low magnetic field is the highest, the iron loss of the specimen by laser cutting is the highest, but the magnetic induction under the low magnetic field is the lowest. It is necessary to adopt suitable production conditions and minimize the deterioration involved, and the magnetic property can be recovered by SRA effectively.

Low-loss B18R065 and B20R070 grain oriented electrical steels for grade 1 energy efficiency distribution transformers

To reduce distribution transformer losses and carbon dioxide emissions, in recent years, the major countries in the world have issued mandatory standards for high-energy efficiency in distribution transformers. In 2013,China has carried out a new standard GB 20052-2013. To meet the update of the standard and energy efficiency,it is important to enhance the magnetic properties of core materials. The new products B18R065 and B20R070 which are developed by Baosteel, are successfully used for grade 1 energy efficiency distribution transformers. And Baosteel becomes one of the companies which can supply both the 0.20 mm and the 0.18 mm gauge grain oriented electrical steels （GOES） in the world. The development principle, material properties, and transformer performance of B18R065 and B20R070 were introduced,which were expected to be a useful reference for materials selection by transformer manufacturers.

Opposite Relationship between Orientation Selection and Texture Memory in the Deformed Electrical Steel Sheets during α→γ→α Transformation

The undesired {111} texture component for the magnetic properties mainly exists in the sheets of electrical steels by the conventional process, whereas the sheets with the non-{111} texture can be obtained by α→γ→α transformation. In this paper, we mainly investigate the opposite relationship between orientation selection and texture memory in the deformed ultra-low carbon steel sheet during →→ transformation annealing. A 0.5 mm thick hot-rolled sheet is directly subjected to transformation. The result shows that the specific transformation textures are not possible to generate in the sheets without deformation. Besides, transformation annealing is conducted on the recrystallized sheets in hydrogen and vacuum, respectively. The near {100} and {110} grains have the growth advantage at the atmosphere/metal interface, and the initial ferrite textures are retained in vacuum. Cold-rolled sheets with different thicknesses are annealed for transformation in vacuum, hydrogen and nitrogen, respectively.The near {100} and {110} textures are still the preferential orientations at the atmosphere/metal interface. When the surface grains have sufficiently large growth advantage, the {111} grains developed by texture memory effect will be annexed. Otherwise, the {111} grains at the center layer of the sheets are hard to be replaced, and they are retained after α→γ→α transformation cycle. The results of deformed sheets annealed with different heating rates in hydrogen show that the growth of initial recrystallization grains has a great effect on variant selection.

Inhomogeneous Distribution of Second Phase Particles in Grain Oriented Electrical Steels

The second phase particles were observed during the whole manufacturing process of conventional grain oriented electrical steels, exhibiting that the areal density of particles in the center was obviously higher than that on the surface at each manufacturing stage. After hot rolling, the approximately equiaxed grains formed upon recrystallization were present on the sheet surface while the deformation structures were retained in the central part. Thus, the dislocation density on the surface was evidently lower than that in the center and this trend became more noticeable after the first cold rolling. Since new precipitates were mainly nucleated at dislocations during both hot rolling and annealing following cold deformation, the difference in dislocation density resulted in the inhomogeneous distribution of particles through the thickness of sheet. According to this, Goss grains, which were usually found near the surface, tended to grow up more easily during the secondary recrystallization treatment.

Microstructure and properties of as-cast Cu-Cr-Zr alloys with lanthanum addition

Cu-0.45 Cr-0.2 Zr-xLa（x = 0-0.48） alloys were prepared by vacuum casting. The effects of La addition and orientation on the microstructure and properties of the as-cast alloy were investigated by an optical microscope, a scanning electron microscope with an energy dispersive X-ray spectrometer, a tensile testing machine and an electrical conductivity tester. The result shows that the addition of La significantly refines the columnar grainsize and decreases the secondary dendrite arm spacing. Trace addition of La improves the room temperature ultimate tensile strength,elongation and electrical conductivity mainly by purifying during melting and casting. The ultimate tensile strength, elongation and electrical conductivity significantly decrease with the increase of La content due to formation of coarse particles and oxides, which severely harm the performance of the Cu-0.45 Cr-0.2 Zr-xLa alloys. The Cu-0.45 Cr-0.2 Zr-0.13 La alloy possesses a good combination of room temperature ultimate tensile strength, elongation and electrical conductivity. In addition, room temperature ultimate tensile strength and electrical conductivity along transverse direction of the ingot are higher than that along longitudinal direction,which is mainly ascribed to different distribution of grain boundary and grain orientation.

Organic ligand mediated evolution from superalkalis to superatomic molecules and nanowires

Superatoms are considered as promising building blocks for customizing superatomic molecules and cluster-assembly nanomaterials due to their tunable electronic structures and functionalities.Electron counting rules,which mainly adjust the shell-filling of clusters,are classical strategies in designing superatoms.Here,by employing the density functional theory(DFT)calculations,we proved that the 1,4-phenylene diisocyanide(CNC_(6)H_(4)NC)ligand could dramatically reduce the adiabatic ionization potentials(AlPs)of the aluminum-based clusters,which have 39,40,and 41 valence electrons,respectively,to give rise to superalkali species without changing their shell-filling.Moreover,the rigid structure of the ligand can be used as a bridge firmly linking the same or different aluminum-based clusters to form superatomic molecules and nanowires.In particular,the bridging process was observed to enhance their nonlinear optical(NLO)responses,which can be further promoted by the oriented external electric field(OEEF).Also,the stable cluster-assembly XAl_(12)(CNC_(6)H_(4)NC)(X=Al,C,and P)nanowires were constructed,which exhibit strong absorption in the visible light region.These findings not only suggest an effective ligand-field strategy in superatom design but also unveil the geometrical and electronic evolution from the CNC_(6)H_(4)NC-based superatoms to superatomic molecules and nanomaterials.

Enhancement of ion transport in porous media by the use of a continuously reoriented electric field

Electromigration in porous media is enhanced by a new type of electrokinetic processing. Compared with a single -oriented electric field, a continuously reoriented electric field was proven to sharply enhance mass transport of several heavy metals in kaolin. The initial concentration of the metals was: Cd: 250 mg/kg; Cu: 250 mg/kg; Ni: 250 mg/kg; Zn: 900 mg/kg. Electric field reorientation was obtained by the use of a fixed anode and a cathode that rotated at different frequencies (0, 0.25, 1.00, 1.25, 2.00, 5.00 and 10.00 r/m). Mass transport evidently increased from 0 r/m to 1.25 r/m, and then decreased as the rotation speed reached 10 r/m. From 0 r/m to 1.25 r/m, mass transport increased 2.87 times for Cd, 3.17 times for Cu, 2.11 times for Ni, and 4.13 times for Zn. We suggest that continuous reorientation of the electric field facilitates the advance of ions through kaolin pores, minimizing the retardation effect caused by media tortuosity.