Bare crystal is one of surface quality problems and may show its features in different extents, such as point bare crystal in small scale or large areas of bare crystals. The morphologies and local compositions of some kinds of point bare crystals in low temperature heated and nitriding grain oriented steels were examined in this paper, and the possible reasons for their formation were analyzed and suggested. The results showed that at least three kinds of point bare crystals are observed, namely, the one containing only steel matrix compositions without glass layer and insulating layer, the one that contains insulating layer but without glass layers and the one that contains a Mgrich ring band around it and lose its glass layer or insulating layer in different extents in the center. The reasons of the formation of the point bare crystals should be diverse because of the variety in their morphologies and local composition.

In order to study the effect of rare earth yttrium (Y) on the magnetic properties of cold rolled high silicon steel sheets,  6.5 %  Si high silicon steel sheets with three different Y contents (without rare earth, containing  0.012 %Y  and  0.030 %  Y) were taken as research objects, and hot rolling, warm rolling, cold rolling and annealing processes were adopted to prepare  0.2  mm thick high silicon steel sheets. The effects of rare earth Y on the structure, texture and magnetic properties of the high silicon steel sheets were analyzed by means of metallographic microscope (OM, optical microscope), scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The results showed that the average grain sizes of annealed sheets gradually decreased with the increase of Y content, which were 194 μm, 125 μm and 84 μm, respectively. And as the increase of Y content, the {100} texture was continuously weakened, and the overall intensity of η (〈100〉//RD) texture increased first and then decreased, while the intensity of harmful γ (〈111〉//ND) texture decreased first and then increased. When the mass fraction of Y content was  0.012 % , although the core losses at the frequencies of 50~ 1 000  Hz were slightly higher than that of the high silicon steel without Y, the magnetic induction of B50 was the highest ( 1.647 T ) due to the enhancing η texture and the weakening γ texture. 

The steelmaking production of high grade nonoriented silicon steel 50W350 was introduced at Lianyuan Iron and Steel Group Co.，Ltd.(Liangang), from production organization, preparation of raw and auxiliary materials to process and composition control. And the ladle top slag, continuous casting protection slag and inclusion were also briefly analyzed and studied. The production practice showed that Liangang has the ability to produce high grade nonoriented silicon steel 50W350, of which the trail production has reached the expected target, meeting customers’ requirement on quality.

The high grade non oriented silicon steel samples of 3.2 % Si were firstly normalized at different temperatures, and then rolled and annealed in the same way, and at last the precipitates in the steel samples were observed in this paper. The results of the precipitate observation showed that the precipitate size in normalized plates was gradually increased and the areal density of  the precipitate gradually decreased as the normalizing temperatures increased, while  in final annealed plates the areal density of  the precipitate was firstly decreased and then increased. And meanwhile, it can be found that the amounts of the precipitaes with the size from 50 to 100 nm were maximized  when the normalizing temperature was set between 850 ℃ and 950 ℃.

The microstructure, texture and magnetic properties of  1.1 %  Si non oriented silicon steel with normalizing and non normalizing were analyzed by the technology of XRD, EBSD and magnetic property measuring device. The results showed that normalizing treatment can increase the grain size of steel and make the microstructure more uniform, and optimize the magnetic properties. On the treatment of 980 ℃× 140 s normalizing, the average size of the microstructure of hot rolled product increases by about 23 μm, and the grain size of the final product increases by about 12 μm. And meanwhile, the {100} texture of the structure increases by about  3.0 % , the {111} texture decreases by about  2.6 % , the {100} texture of the finished product increases by about  0.43 % , the {111} texture decreases by about  6.5 % , and magnetic induction of  B50 increases by 0.021 T，iron loss of P1.5/50 decreases by 0.34 W/kg. 

In order to explore the influence of blanking process on the insulation of blanking surface of cast aluminum core, highprecision shearing machine was used to simulate the influence of different gaps on the section morphology and burr height of nonoriented silicon steel used for constant frequency compressor after blanking, and then the influence of different blanking process on the blue insulation of blanking surface of cast aluminum core was determined. The results showed that, as the relative clearance of blanking increased from 8 % to 18 %, the proportion of bright zone in cross section decreased from 72.5 % to 45.5 %, and the reaction time of cupric sulfate titration increased from 191 s to 232 s, and the burr height increased from 2.6 μm to 9.1 μm. The optimal die clearance of nonoriented silicon steel for constant frequency compressor should be controlled between 10 % and 15 %.

The mechanical properties of high grade nonoriented electrical steels which were processed by three different methods of punching machine, milling machine and laser, were analyzed through tensile test and microstrtucture analysis. The results showed that, in  the aspect of processing surface, the milling and laser machining surfaces are more regular and smooth than that of punch processing. And for burr, the burr in punch processing is the most serious, laser cutting secondly, milling machine processing for the best. At the same time, it can be seen that in order to reduce the effects of processing methods on the high grade nonoriented electrical steel's mechanical properties, using laser cutting technology to instead traditional punch processing is feasible when using such materials.

Combined with the performance parameters of the cold rolling continuous annealing unit in the production of strip steels in Qiansteel, both the diameter, the material, the strip cladding angle and the tension amplification coefficient of No.1 tension roller in the entrance section of the unit, and the relevant parameters of reducer, drive motor were designed and accounted in this paper. The results showed that the checked power of the motor met the actual needs of production, which can provide reference to the design of similar units.

In viewing of the troubles occurred in the running process of  the spot cooling system of the single stand reversing mill in Cold Rolling Plant of Maanshan Iron and Steel Co. Ltd., and combining with long time's solving experience , the troubleshooting and solution was systematically researched and summarized in this paper. Then two diagrams were refined which can helpfully find out the reason and solution of occuring problem of the spot cooling system. The actual pratice showed that this method can successfully and rapidly solve many problems of the spot cooling system. 

The patent quantity of cold rolled oriented silicon steel coating and distribution of technology fields applied in China from 1999 to 2019 were summarized. The analysis results indicated that，there are 121 patents of coldrolled oriented silicon steel coating applied in China, 96 patents applied by native producers and 25 patents applied by abroad producers．The typical patent technology include improving forsterrite quality, no forming forsterrite, containing chromate insulating coating and chromiumfree and environment friendly coating and so on，The developing trend of silicon steel coating is mainly chromiumfree and environment friendly insulating coating．