The microstructure evolution process of the reaction between silicon oxide and magnesium oxide in oxide layer was observed by focused ion beam microscope(FIB) in simulating the high temperature annealing process of grain-oriented silicon steel in laboratory.Then the distribution of Mg, Al and Si in the near surface layer of the sample section was analyzed by energy dispersive spectrometer (EDS). Finally, the structure of the magnesium silicate glass film was analyzed by transmission electron microscopy(TEM). The results showed that: (1) the diffusion rate of Mg ions is the major factor affecting the reaction of magnesium oxide and silica; (2) Mg ions diffuse firstly along the interface between silica oxide and iron matrix, and gradually coat the silica particles, and then Mg ions begin to diffuse into and react with the silica particles as the further increase of temperature; (3)as the temperature increasing, the Al decomposed by AlN gradually converts the magnesium silicate (Mg2SiO4) at the pinning site into magnesium aluminum spinel (MgO·Al2O3).

The characteristics of the motors used in electric drive cars and the requirements for silicon steel were described, and the electromagnetic properties and mechanical properties of high yield strength nonoriented silicon steel and traditional nonoriented silicon steel were compared and analyzed by experiment. Through the verification and analysis of the finite element model, the highyieldstrength silicon steel motor can achieve the characteristics of low loss and high mechanical strength at high speed, which can help for the application of soft magnetic materials and the optimization of motor structure to form a closed-loop mode.

The Effects of the elements of Ti and S on the second phase precipitates of high grade non-oriented silicon steels in equilibrium state and mass production have been studied. The results showed that the precipitation starting temperature and stable precipitation amount of Ti（C,N) and MnS were both increased as the increase of the contents of Ti and S in equilibrium state.While in industrial production, the average sizes and area densities of the two precipitates in normalized plate’s samples with high Ti and low S contents were both higher than the samples with low Ti and high S contents, but in finished plate, it can be seen that the two precipitates’ average sizes and area densities in the samples with high Ti and low S contents were both lower than the samples with low Ti and high S contents.

The effects of normalizing temperature on the microstructure and properties of nonoriented electrical steel were studied in this paper. The results showed that the texture characteristics of the normalized plate showed gradient distribution. The center layer textures were mainly α* oriented grain of {100}〈021〉,{114}〈481〉,{112}〈421〉 , and the surface and subsurface textures were mainly Goss and brass oriented grain. When the normalization temperature raised from 840 ℃ to  920 ℃ after 5min normalization treatment, the grain sizes of normalized plate and finished plate were increased and the texture were improved, the volume fraction of {100} oriented grains increased and the {111} and {112} oriented grains decreased in the center layer of finished plate, the iron loss P1.5/50 decreased by about 0.106 W/kg, the magnetic induction B5000 increased by about 0.016 7 T.

Tool electrical steel BGJW650 is mainly used in agricultural machinery motors, which has the characteristics of high magnetic induction and low cost. Due to the broad market of agricultural machinery and the rapid renewal of many machinery, the market demand of BGJW650 is huge. The steel was produced in the thin slab continuous casting and rolling production line of BX Steel, by adopting the chemical composition of no Al, no P, low Mn content and mass fraction of C less than 0.040 %, without deep decarburization, and the hot rolling process of low-temperature heating and high finishing rolling and coiling temperature. The produced tool electrical steel BGJW650 met the user’s requirements, with low cost, and iron loss P1.5/50 less than 6.2 W/kg and magnetic induction B5000 between 1.74 and 1.76 T.

The factors affecting the adhesion of electrophoretic paint were studied through the industrial test of electrophoretic paint on inorganic components, organic components and non-oriented silicon steel coating samples containing different resin components. The results showed that the inorganic components in the coating have no adverse effect on the adhesion of electrophoretic paint, and the resin components in the coating have a significant effect on the adhesion of electrophoretic paint.

During the production of silicon steel,the abnormal state of furnace roll of horizontal annealing furnace such as bending deformation,knot on roll surface will generate a great mount of product defects.If these defects can not be solved by other methods,we have to choose to change the problem rolls. The special tool to change rolls on line developed by Maanshan Iron and Steel Co., Ltd. and its operation measures were introduced in this paper. It can be seen in practice that by using this tool, the changing time and energy consumption were reduced, and the problem of online changing of rolls was basically solved.

The characteristics, roll wear and thermal expansion of high speed steel rolls were studied and analyzed, and the rolling process was optimized by using full frame high speed steel(HSS) rolls in nonoriented silicon steel rolling. The results showed that: compared with ordinary rolls, HSS rolls can delay edge drop and control the section of nonoriented silicon steel, so as to improve the accuracy of the same plate difference in the subsequent process.