MX2012008269A

MX2012008269A - Cold rolled electromagnetic steel sheet used for rapid cycling synchrotron and producing method thereof.

Info

Publication number: MX2012008269A
Application number: MX2012008269A
Authority: MX
Inventors: Zhanyuan Hu; Xiao Chen; Lingfeng Chen
Original assignee: Baoshan Iron & Steel
Priority date: 2010-08-26
Filing date: 2011-04-13
Publication date: 2012-11-23
Also published as: US20120318411A1; EP2532766A1; RU2012130145A; WO2012024934A1; CN102373367A; JP2013515857A

Abstract

A cold rolled electromagnetic steel sheet used for a rapid cycling synchrotron (RCS) comprises the components in wt% as follows: C:0.001-0.003%, Si:0.60-0.90%, Mn:0.40-0.70%, Pâ¿¤0.04%, Al:0.60-0.80%, Sâ¿¤0.0035%, Nâ¿¤0.003%, and balance Fe. A method for producing the cold rolled electromagnetic steel sheet comprises the following steps: 1) smelting and casting, in which the molten steel with the composition described above is subjected to smelting, RH refining and casting to obtain billet; 2) hot rolling; 3) normalizing, with its temperature being 960-980â¿¿ and time for 30-60s; 4) pickling and cold rolling; 5) annealing, with its temperature being 850-870â¿¿ and time for 13-15s; and 6) coating to obtain non-oriented silicon steel. The cold rolled electromagnetic steel sheet has low coercive force, high magnetic induction and low core loss.

Description

ELECTROMAGNETIC STEEL SHEET LAMINATED IN COLD FOR QUICK CYCLE SYNCHROTRON, AND METHOD OF MANUFACTURE OF THE SAME FIELD OF THE INVENTION The present invention relates to a cold-rolled electromagnetic steel sheet particularly with a cold-rolled electromagnetic steel sheet for a fast cycle synchrotron and the manufacturing method thereof.

BACKGROUND OF THE INVENTION One of the important characteristics of a fast cycle synchrotron is that the magnetizing current operates in a sinusoidal current state driven by DC; a fast-cycle synchrotron (RCS) with relatively high energy is used to accelerate particles in order to increase energy; and when a certain requirement for beam energy is obtained, it is dragged from a ring and dispersed in a spallation target. Based on the characteristics of the device, there are relatively high requirements for cold-rolled electromagnetic steel sheets to make the magnet: Low coercivity: when intense returns are magnetized to zero after reaching 10 Oersted (Oe), the material coercivity He = 79.6 A / m.

High electromagnetic induction: B50 = 1.74T, with the controlling object of 1.75 ~ 1.76T; low iron losses: P15 / 50 = 4.7 / kg, with the controlling object of 3.8 ~ 4.2 W / kg, and iron losses after stretched annealing is P15 / 50 = 3.5 W / kg, with the controlling object of 2.8 ~ 3.2 W / kg.

Normally, in Japan, Europe and the United States, electromagnetic steel sheets are mainly produced for a fast cycle synchrotron by the following method: 1. JPH 05-247604 discloses a method for tempering (by a critical reduction index) mild aluminum steel extra low carbon. The purpose of critical tempering is to thicken the grain of the pure iron belt when the user performs electromagnetic annealing, in such a way that extra low coercivity can be obtained. The drawbacks of the method are that because the critical reduction index is relatively large, which causes aging by stretching, in such a way that the hardness of the pure iron belt is rapidly increased after being supplied. Thus, it will be difficult for the user to puncture the iron strap. And, if the pure iron belt is annealed by means of a bell type furnace, the performance of the magnet will suffer fluctuation caused by the fluctuation of the pure iron belt in the longitudinal direction. 2. Fast cycle synchrotrons in the United States and Germany mainly use ordinary non-oriented electric steel, such as M600 - 50A or M470 - 50A and so on. The product is obtained by the melt-making method - continuous casting - hot-rolled - pickling - cold rolling - reworking - coated. Although the product satisfies the requirements in terms of coercivity of iron losses, its electromagnetic induction is relatively low, with the B50 in fact in the range of 1.69 - 1.72T, which directly affects the capacity of the fast cycle synchrotron.

Thus, it can be seen that the disadvantages of the fast cycle synchrotron by means of the present cold rolled electromagnetic steel sheet are: 1. Iron losses and coercivity satisfy the requirements, but electromagnetic induction must be relatively low.

The performance of the product can satisfy the requirements, but the processing properties and stability are relatively low.

SUMMARY OF THE INVENTION The purpose of the present invention is to provide a cold-rolled electromagnetic steel sheet for a fast-cycle synchrotron, and the method of manufacturing thereof, in order to obtain a sheet of cold-rolled electromagnetic steel with low iron losses , low coercivity and high electromagnetic induction. Namely, this has low coercivity, specifically when the magnetizing intense returns to zero after reaching 10 Oersted (Oe) the coercivity of the material is He - = 79.6 A / m; high electromagnetic induction, which is B50 = 1.75T; and low iron losses of P15 / 50 = 4.2 W / kg, and losses of iron after annealed stretch is P15 / 50 = 3. / kg.

To fulfill the above purpose, the technical solution of the present invention is as follows: A cold rolled electromagnetic steel sheet for a fast cycle synchrotron, whose composition is C 0.001 ~ 0.003% by weight, Si 0.60% ~ 0.90% by weight, Mn 0.40% - 0.70% by weight, P < 0.04% by weight, Al 0.60 ~ 0.80% by weight, S = 0.0035% by weight, N < 0.003% by weight, and the rest of the components are Fe and unavoidable impurities.

The method for manufacturing the cold-rolled magnetic steel sheet for a fast cycle synchrotron according to the present invention includes the steps of: 1) melt and cast, wherein the composition of the cold-rolled electromagnetic steel sheet is C 0.001 ~ 0.003% by weight, Si 0.60% ~ 0.90% by weight, Mn 0.40% - 0.70% by weight, P < 0.04% by weight, Al 0.60 ~ 0.80% by weight, S = 0.0035% by weight, N = 0.003% by weight, and the rest of the components are Fe and unavoidable impurities; carrying out the melting, the refining RH according to the aforementioned components, and then casting the liquid steel to form a semi-finished product, wherein when the refining RH is finished, the free oxygen in the liquid steel is less than 25. ppm; 2) hot rolled; 3) normalized, in which the normalization temperature is controlled so that it is between 960 ° C 980 ° C, the normalization time is 30 ~ 60s; 4) pickling and cold rolling; 5) annealing, in which the annealing temperature is controlled so that it is between 850 ° C ~ 870 ° C, and the annealing time is 13 ~ 15s; 6) Obtain a non-oriented silicon steel product after coating.

In addition, the grain size by means of the steel sheet is more than 40 μp \, preferably it is controlled to be between 40 ~ 50 μp ?.

The design for the composition of the present invention is as follows: Carbon of less than 0.003%, which is in the form of an interstitial phase atom of a cell with iron-based lattice, and which strongly prevents grain growth, and in turn results in the degradation of losses of iron and coercivity. If carbon exceeds 0.005%, decarburization will become difficult, and this will cause magnetic aging, which will result in substantial degradation in terms of iron losses. Therefore, it is preferable to control the carbon content to be less than 0.003%.

The silicon of between 0.60% ~ 0.90%, which is a vital alloying element of the electromagnetic steel sheet, and contributes to improve the resistivity, reduce eddy current losses, reduce iron losses. If the silicon content is too low, the iron losses will degrade, and if the silicon content is too high, the processing capacity of the electric steel will be degraded, and the electromagnetic induction will decrease.

Manganese 0.40% ~ 0.70%, which works mainly to increase resistivity, to reduce iron losses and meanwhile change the condition of the surface. If the manganese content is too high, it will make the following difficult cold processes, and if the manganese content is too low, iron losses will increase, resulting in hot cracking, The phosphorus of less than 0.04%, which mainly works to improve the processing capacity of the steel sheet, because the phosphorus is an element of the polyvinylidene of the grain limit. If its content is too high, the processing capacity will be degraded, and coercivity will rise at the same time.

Aluminum of 0.60% ~ 0.80%, which is mainly to increase resistivity, decreasing iron losses, and decreasing oxidized impurities during steel fabrication, and also increase electromagnetic induction and decrease coercivity. If the aluminum content is too high, it will be difficult to carry out the shedding during the continuous melting, and will result in a decrease of the electromagnetic induction, and if the aluminum content is too low, the iron losses and the coercivity will be they will degrade Sulfur less than 0.0035%. If the sulfur content is more than 0.0035%, the amount of precipitation of manganese sulphide will increase which will impede grain growth intensely, and iron losses and coercivity will be degraded.

Nitrogen of 'less than 0.003%. If the nitrogen content is more than 0.003%, the amount of aluminum nitride precipitation will increase which will impede grain growth intensely, and iron losses and coercivity will be degraded.

In the manufacturing method of the present invention, when the RH refining process is completed, the free oxygen content in the liquid steel is less than 25 ppm. Thus, in general, the oxidized impurities of the steel are reduced, and then the iron losses, and the coercivity will effectively decrease.

When the RH refining is completed, if the free oxygen content in the liquid steel is more than 25 ppm, the excess free oxygen will act with the Si, Mn, P, Al, in the steel to form a small amount of 3 impurities oxidized from the composition of Si02 - A1203 - MnO, accompanied by a slight amount of P2O5, in order to distort the glass lattice of the cured material, which results in the increase of the magnetostatic energy and the elastic magneto energy, and increases the resistance of movement in the domain wall.

Meanwhile, during the hot rolling under 1100 ° C ~ 880 ° C, the three oxidized impurities of the S1O2 - AI2O3 - MnO composition have plasticity, in order to be rolled into chain and impurity in bar form. During the cold rolling process, the three oxidized impurities of the composition of Si02 - Al203 - MnO, present cracking characteristics, in such a way that it can be easily rolled into a long chain of impurities in the form of particles, that is, forming oxidized impurities of compound mainly of impurity type C (chain shape and rod shape) and secondarily impurity of type D (dotted). This results in difficulty in magnetization, decrease in intense electromagnetic induction and increase in coercivity.

The intensity of the deoxidation of the metallic elements differs from the point of oxygen balance in the steel, which in sequence will be Al, Si, Mn. Therefore, during the melting, when controlling the total amount of Si + Al at 1.2% ~ 1.7%, the S1O2 - AI2O3 formed in the refining proface can be sufficiently removed from the steel. Meanwhile, when the free oxygen is kept below 25 ppm. And the Mn in elevation is controlled to be 0.40% ~ 0.70%, that is, in an atmosphere of poor oxygen and rich manganese, the production of the three oxidized impurities of the Si02-? 1203 - ??? it is further reduced. Thus, the oxidized impurity of the composition mainly produced in the following processes of hot rolling and cold rolling, which is the impurity type C (in the form of chain and in the form of a bar) and secondarily of the impurity type D (in the form knitted), can be reduced, such that the thin growth is promoted, the electromagnetic induction is improved, and the coercivity is lowered.

To normalize, the normalization temperature is controlled to between 960 ° C ~ 980 ° C, and the normalization time is 30 ~ 60s. The control of the normalization temperature is related to Si, Mn, Al, N, C, S. The increase in the contents of Si, Al, Mn, can help to lower the harmonization temperature, but if the normalization temperature is too low, and if the normalization time is too short, the accumulation and growth of the product precipitated from the steel will be adversely affected, which may result in the decrease of magnetic induction in the degradation of iron losses and coercivity . If the contents of Si, Al, Mn, decrease, the normalization temperature will increase, but if the normalization temperature is too high, and if the normalization time is too long, the losses on the steel resignation will increase, part of the precipitated products -of steel, such as Mn , A1N, and the like, are dissolved solids, which will result in dispersion after cold rolling and annealing, so that deposition of carbon and nitrogen will precipitate, which will severely degrade iron losses and coercivity. For this purpose, while the normalization temperature is controlled, the contents of sulfur and nitrogen will be required to be S = 0.0035% and N = 0.003%.

To anneal, the annealing temperature is controlled between 850 ~ 870, an annealing time of 13 ~ 15s. If the annealing temperature is too high, and if the annealing time is too long, the diameter by means of the grain will be excessively, thus decreasing the electromagnetic induction, and the degradation of the processing capacity; although if the annealing temperature is too low, and if the annealing time is too short, grain growth will be prevented, so that iron losses and coercivity will be degraded, because the presence of phosphorus in steel, which results in a polyvinylidene with grain limit. For this purpose, when the annealing temperature is controlled, the content of the element P is required to be P < 0.04% The average grain size in the steel sheet is more than 40 μ ??, this is preferably controlled so that it is between 40 ~ 50 μp ?. Grain size has a certain relationship with coercivity. If the grain size is too small, the iron losses will increase, and the coercivity is relatively large. If the grain is too large, the area occupied by the gain limit will decrease, so that the coercivity will decrease at the same time, but the magnetic induction will decrease further.

Beneficial Effects of the Invention. 1. The present invention reduces the contents of the impure element and the impurity, in order to further increase the magnetic induction, and decrease the coercivity, measured by providing an optimized content and in the exploration on favorable elements, such as Si, Mn, Al By means of the preferred design for the normalization process and the annealing process, and the thickening of the precipitated products and the grain are facilitated, in such a way that the iron losses and the coercivity decrease, thus, a laminate can be obtained. electromagnetic steel cold rolled for a fast cycle synchrotron with low iron losses, low coercivity and high magnetic induction. Provide solid guarantee in terms of raw material to improve the technical level for the rapid cycle synchrotron of our country, and increase the form of product development. 2. The cost of the product is competitive. The present invention performs the annealing and coating based only on a time of cold rolling, instead of applying the method of tempering (by means of the critical reduction index) steel rest of extra-low aluminum carbon, in such a way that the operation is simplified, and the cost is competitive.

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to these embodiments.

The main composition of the steel used in the embodiments of the present invention and those of the comparative example are listed in Table 1.

After the liquid steel sequentially passes a converter, and after it is refined to RH and poured to form a semi-finished product, it suffers from hot rolling, normalizing, pickling, cold rolling, annealing and coating to obtain an unoriented electric steel product. During such processes, the semi-finished produced is hot-rolled to make a 2.6mm steel belt, then the 2.6mm hot-rolled steel belt is normalized with the controlled normalization temperature at 970 ° C and a time of normalization that is controlled to be 30 ~ 60s. The standardized steel belt is cold rolled to be a 0.5mm steel belt, and then it is finally annealed and coated. The final annealing temperature after cold rolling is 850 ° C, and the annealing time is controlled to be 13 ~ 15s, and in this way a cold-rolled electromagnetic steel sheet is obtained.

The electromagnetic performance index of the cold rolled electromagnetic steel sheet of the modalities and those of the comparative examples is listed in Table 2.

Table 1 % in weigh) Table 2 It can be seen in tables 1 and 2 that the index for the electromagnetic performance of the steel sheets obtained by the modalities is significantly advantageous over those of the electromagnetic performance of the steel sheets obtained through the comparative examples, and Steel blades of the modalities completely satisfy the requirements for use in the fast cycle synchrotron.

In summary, based on the mechanism of the effects of various factors on coercivity, iron losses, magnetic induction of laminated electromagnetic steel sheet, the present invention discovers and optimizes the mixing ratio of the Si-beneficial elements. , Mn, Al, and the like to reduce the contents of the impurities, on the basis of a cold rolling of a time, in such a way that the magnetic induction is further improved. By means of the preferred design for the normalized process and the annealing process, the thickening of the precipitated products and the grain are facilitated, in such a way that it decreases iron losses and coercivity, thus, a sheet of electromagnetic steel laminated in cold for a fast cycle synchrotron with low iron losses, low coercivity and high magnetic induction.

Non-oriented electric steel is applied to a device called a Fast Cycle Synchrotron with a source of Neutron of China Spallation (CSNS / RCS), which belongs to the Institute of Modern Physics of the Chinese Academy of Sciences. The product has the characteristics of low iron losses and high magnetic induction. The success of applying the present invention will provide a solid guarantee in terms of raw material to improve the technical level of the rapid cycle synchrotron of our country, and expand the way of product development.

Claims

NOVELTY OF THE INVENTION Having described the present invention, it is considered as a novelty and, therefore, what is contained in the following is claimed as property. CLAIMS 1. A cold-rolled electromagnetic steel sheet for a fast cycle synchrotron, characterized in that it has a composition of C 0.001 ~ 0.003% by weight, Si 0.60% ~ 0.90% by weight, Mn 0.40% ~ 0.70%, P < 0.04% by weight, Al 0.60 ~ 0.80% by weight, S < 0.0035% by weight, N < 0.003% by weight and the rest is Fe and unavoidable impurities. 2. A method for manufacturing the cold-rolled electromagnetic steel sheet for a fast cycle synchrotron as in claim 1, characterized in that it includes the steps of: 1) melt and strain, wherein the composition of the cold rolled electromagnetic steel sheet is C 0.001 ~ 0.003% by weight, Si 0.60% ~ 0.90% by weight, Mn 0.40% ~ 0.70% by weight, P < 0.04% by weight, Al 0.60 ~ 0.80% by weight, S < 0.0035% by weight, N = 0.003% by weight and the rest is Fe and unavoidable impurities; where the melting is carried out, the refining RH under the same composition, and then the casting of the liquid steel to form a semi-finished product, where when the refining RH is finished, the contents of free oxygen in the liquid steel are lower at 25 ppm; 2) hot laminating; 3) normalize, in which the normalization temperature is controlled between 960 ° C ~ 980 ° C, and the normalization time is 30 ~ 60 seconds. 4) cold pickling and laminating; 5) annealing, wherein the annealing temperature is controlled between 850 ° C ~ 870 ° C, and the annealing time is 13 ~ 15 seconds; 6) obtain a non-oriented silicon steel product after coating. 3. The method of manufacturing the cold-rolled electromagnetic steel sheet for a fast cycle synchrotron according to claim 2, characterized in that the average grain size in the steel sheet is more than 40 μ? T ?. 4. The method for manufacturing the cold-rolled electromagnetic steel sheet for a fast cycle synchrotron according to claim 2, characterized in that the average grain size of the steel sheet is controlled to be between 40 ~ 45 μ? . SUMMARY OF THE INVENTION A cold-rolled electromagnetic steel sheet for a fast-cycle synchrotron, and a method of manufacturing it, the method includes the steps of 1) melting and casting, the composition of the cold-rolled electromagnetic steel sheet is C 0.001 ~ 0.003% by weight, Si 0.60% ~ 0.90% by weight, Mn 0.40% ~ 0.70% by weight, P < 0.04% by weight, Al 0.60 ~ 0.80% by weight, S < 0.0035% by weight N = 0.003% by weight, and the rest is Fe; melt and re-spin RH, and then strain to form a semi-finished product; 2) hot laminating; 3) normalize, in which the normalization temperature is controlled between 960 ° C ~ 980 ° C, and the normalization time is 30 ~ 40s; 4) cold pickling and laminating; 5) annealing, wherein the annealing temperature is controlled so that it is within 850 ° C ~ 870 ° C, and the annealing time is 13 ~ 15s; 6) obtain a non-oriented silicon steel product after coating. The cold-rolled electromagnetic steel sheet of the present invention has low coercivity, specifically in the event that the magnetizing intensity returns to zero after reaching Oersted (OE), the coercivity of the material is He = 79.6 A / m; high magnetic induction, which is B50 =

1. 75T; and low iron losses of P15 / 50 < 4.2 W / kg, and iron losses after the annealed stretch is P15 / 50 < 3.5 W / kg.