KR101262483B1 - Wire rod, drawn wire rod having superior magnetic property and method for manufacturing thereof - Google Patents

Abstract

The present invention relates to a wire rod, a wire rod, and a manufacturing method thereof having excellent magnetic properties, and more particularly, a wire rod having excellent magnetic properties, which can be used in transformers, automobiles, electrical and electronic products, which require low iron loss and high permeability, It relates to a wire rod and a manufacturing method thereof.
The present invention is composed of weight%, C: 0.005 ~ 0.01%, Si: 3.0 ~ 10.0%, Mn: 0.1 ~ 2.0%, Al: 0.008 ~ 0.018%, N: 0.0015 ~ 0.0030%, balance Fe and other unavoidable impurities The present invention provides a wire rod, a wire rod, and a method of manufacturing the same having excellent magnetic properties including a goth structure of 95 to 98.5 area%.
According to one aspect of the present invention, it is possible to reduce the manufacturing cost by not using expensive alloy elements, it is possible to provide a wire rod and a wire rod having a direction only in the usual manufacturing process without the addition of manufacturing equipment.

Description

WIRE ROD, DRAWN WIRE ROD HAVING SUPERIOR MAGNETIC PROPERTY AND METHOD FOR MANUFACTURING THEREOF}

The present invention relates to a wire rod, a wire rod, and a manufacturing method thereof having excellent magnetic properties, and more particularly, a wire rod having excellent magnetic properties, which can be used in transformers, automobiles, electrical and electronic products, which require low iron loss and high permeability, It relates to a wire rod and a manufacturing method thereof.

As the core material of most medium and large transformers, directional or non-oriented electrical steel sheet is used. In particular, while requiring greater efficiency than the existing, the necessity of various research and development for the miniaturization and light weight of the mechanical device has emerged, and therefore, the development and research of high-quality oriented electrical steel sheet is very indispensable reality.

Particularly, since the grain-oriented electrical steel sheet is manufactured to be easy to magnetize in the rolling direction of the steel sheet and has high magnetic properties in the rolling direction, it is necessary to artificially form a texture showing magnetic properties by adding high Si to the ultra low carbon steel. However, in the case of the grain-oriented electrical steel sheet, in order to improve the magnetic properties, the Si component may contain about 6.5% or more to exhibit the characteristics of the grain-oriented electrical steel sheet.

In addition, in the case of a grain-oriented electrical steel sheet, in order to artificially form a Goss structure, which is an aggregate structure, it has a disadvantage of performing heat treatment in a high temperature and nitrogen atmosphere. This is because it is necessary to control the <100> crystal orientation, which is the crystal orientation for the maximum magnetic induction value.

On the other hand, although recently improved the way to improve the magnetic properties of the electrical steel sheet by controlling the texture or surface coating of the grain-oriented electrical steel sheet, in the case of the electrical steel sheet used as a transformer, Precise machining is required to suppress slit, shear, or warp, and when the iron core is relatively small, the machining itself becomes difficult, and the volume of the distortion part by the machining occupying the whole product of the iron core This becomes relatively large, which causes a problem that the magnetic properties are significantly reduced.

In order to solve this problem, a technology for manufacturing wire rods for small motors mounted on small transformers or automobiles by manufacturing electromagnetic wires or electric wires has been developed. When electrical steel sheets are made of wire rods, rolling and surface defects are suppressed. It does not require harsh process control and has the advantage of solving the problem of yield reduction by lamination of electrical steel sheet.

Such a representative technique is Japanese Patent Laid-Open No. 2001-115241. The patent is to manufacture a material for electronic steel wire excellent in drawing workability, in particular cold drawing workability even in the hot rolled state (As rolled), including Si in the range of 0.1 to 8% and at the same time the sum of C + N + O + S The component system is limited to less than 0.015%. However, in the case of the above patent, since the carbon component is controlled by ultra-low carbon, RH (Ruhrstahl-Heraues) degassing process should be added, and complex deoxidation should be performed with a long vacuum degassing time. It has the disadvantage of not being able to. In addition, since Cr is added in an amount of 0.1 to 15% to improve magnetic properties, it is not possible to solve the problem of price increase due to the addition of alloying elements.

As a technology complementing the above patent, there is Japanese Patent Laid-Open No. 2000-045051. The patent relates to an electronic steel wire having excellent iron loss and workability, in which the sum of the C, N, O, and S components is limited to 0.015% or less, and the grain size and the wire diameter after wire drawing are defined. : 2% or less, Al: 2% or less, Cu: 2% or less are added, and the steel wire which is excellent in iron loss and workability is disclosed. However, the electronic steel wire disclosed in the patent has the disadvantage that there is no problem of the source material price increase due to the increase in the addition amount of alloying elements, there is no magnetic proposal in the hot rolling state, and there is no specification of the aggregate fraction.

On the other hand, there is another invention disclosed in Japanese Unexamined Patent Publication No. 2001-131718, the patent is limited to the sum of the C, N, O, S components to 0.025% or less, wire rods of 0.01 ~ 1.0mm diameter manufactured through drawing Presenting. However, the patent also has the disadvantage that the addition of expensive alloying elements such as Cr, Ni, Cu is essential, there is no specific organizational proposal for magnetic and suggestion of magnetic value.

In particular, in the case of the above-described patents, all magnetic properties have the disadvantage that they have a value close to that of the non-oriented electrical steel sheet.

One aspect of the present invention is to provide a wire rod, a wire rod, and a method for manufacturing the same having excellent magnetic properties by controlling the composition and activating Goss structure through a common process of rolling without expensive alloying elements. will be.

The present invention is composed of weight%, C: 0.005 ~ 0.01%, Si: 3.0 ~ 10.0%, Mn: 0.1 ~ 2.0%, Al: 0.008 ~ 0.018%, N: 0.0015 ~ 0.0030%, balance Fe and other unavoidable impurities It provides a wire with excellent magnetic properties including 95 ~ 98.5 area% of goth tissue.

At this time, the saturation magnetic flux density of the wire rod is preferably 270 ~ 310emu.

The present invention is composed of weight%, C: 0.005 ~ 0.01%, Si: 3.0 ~ 10.0%, Mn: 0.1 ~ 2.0%, Al: 0.008 ~ 0.018%, N: 0.0015 ~ 0.0030%, balance Fe and other unavoidable impurities It provides a new material with excellent magnetic properties including 97.5 ~ 99.5 area% goth tissue.

It is preferable that the saturation magnetic flux density of the drawing material is 300 to 330 emu.

The present invention is in weight percent, consisting of C: 0.005 to 0.01%, Si: 3.0 to 10.0%, Mn: 0.1 to 2.0%, Al: 0.008 to 0.018%, N: 0.0015 to 0.0030%, balance Fe and other unavoidable impurities. A heating step of heating the steel at 1000 to 1100 ° C .; A ball rolling step of rolling the heated steel by wire; An annealing treatment step of annealing the wire-rolled wire; And a surface coating step of coating a coating agent on the surface of the annealing wire.

At this time, it is preferable that the process of rolling is carried out at 900 ~ 1000 ℃, the cross-sectional reduction rate is preferably 75 to 85%. After the cold rolling step, it is preferable to cool the cold rolled wire at a rate of 0.05 ° C / s or less. The annealing treatment step is preferably performed for 5 to 10 minutes at 700 ~ 800 ℃ by heating the ball-rolled wire at a rate of 5 ~ 15 ℃ / s, after the annealing treatment step 10 It is preferable to cool to 150 degreeC by the rate of degrees C / s or less. As the coating agent, one or more selected from the group consisting of MgO, Al ₂ O ₃ , ZnO, and ZrO ₂ may be used.

The present invention provides a method for producing a wire rod having excellent magnetic properties, including a step of drawing the wire rod produced by the above method using at least one drawing lubricant selected from the group consisting of MgO, Al ₂ O ₃ , ZnO, and ZrO ₂ . To provide.

According to one aspect of the present invention, it is possible to reduce the manufacturing cost by not using expensive alloy elements, it is possible to provide a wire rod and a wire rod having a direction only in the usual manufacturing process without the addition of manufacturing equipment.

The inventors of the present invention, while conducting a study for imparting excellent magnetic properties to the wire rod, by controlling the composition component can be produced a wire rod and a wire rod having a high magnetic properties through a conventional process for rolling without expensive alloying elements Became aware of.

Hereinafter, the present invention will be described in detail.

Carbon (C): 0.005-0.01 weight%

C is dissolved in the wire and causes lattice distortion and aging in processing, while reducing ductility. When the C is added less than 0.005%, there is a problem in that it is not possible to form a uniform goth structure in the wire rod, when exceeding 0.01%, the magnetic content is lowered by carbon solid solution, the content of carbon is 0.005 It is preferable to limit it to -0.01%.

Silicon (Si): 3.0-10.0 wt%

Si is an effective component to improve the iron loss and magnetism by increasing the electrical resistance of the wire rod, but if less than 3%, the magnetism is lowered due to the lack of addition amount, and if it exceeds 10%, the work hardening during the wire rod is rapidly progressed and can be rolled Since there is no disadvantage, the content of the silicon is preferably limited to 3.0 to 10.0% by weight.

Manganese (Mn): 0.1-2.0 wt%

Mn is a useful component that can improve the electrical resistance and improve the iron loss characteristics of the wire rod, but if it is added less than 0.1%, Mn can not play a role of compensating the strength when rolling, and when it exceeds 2.0%, it is processed like Si There is a problem that causes a hot rolling problem by increasing the curing effect. Therefore, the content of manganese is preferably limited to 0.1 ~ 2.0%.

Aluminum (Al): 0.008 ~ 0.018 wt%

In the case of Al, it is preferable to limit the content in conjunction with the nitrogen control range because it is an element effective for improving the magnetic properties through the control of nitrogen in the steel. When the Al is added less than 0.008% has the disadvantage that it can not effectively control the nitrogen, and when added in excess of 0.018%, Al may precipitate in an atomic state to lower the magnetism of the aluminum, The content is preferably limited to 0.008 to 0.018%.

Nitrogen (N): 0.0015 to 0.003 wt%

In the case of N, the formation of goth structure is suppressed through lattice deformation and nitride formation with alloying elements due to penetration into the crystal lattice, which causes aging and ductility deterioration. Nitrogen is controlled at less than 0.0015% because it is a very harsh process in the steelmaking process and cannot be implemented in the actual process.If it exceeds 0.003%, nitrogen in the steel can move freely and the Al content is increased to coarsen AlN. In order to make it possible, the content of nitrogen is preferably limited to 0.0015 to 0.003%.

By limiting the composition range as described above, excellent magnetic properties, that is, directivity, can be imparted to the wire rod. The wire rod of the present invention includes a Goss structure of more than 95 area%, such that a large amount of goth structure is generated as compared to the existing electrical steel sheet or a wire rod having magnetic properties, so that the wire rod has excellent magnetic properties, that is, It has directionality. When the goth structure is less than 95%, the wire rod cannot be provided with directionality and thus has non-directional magnetic properties. That is, the more the goth tissue is generated, the better, but as a process limit, the upper limit of the goth tissue is limited to 98.5%.

In addition, the wire rod of the present invention preferably has a saturation magnetic flux density of 270 emu or more. When the saturation magnetic flux density is less than 270 emu, it is difficult to impart orientation to the wire rod and may have non-directional magnetic properties. The higher the saturation magnetic flux density is, the higher the value of the Goth structure, the better the magnetic properties.

Hereinafter, the manufacturing method of the present invention will be described in detail.

It heats at 1000-1100 degreeC about the steel material which satisfy | fills the composition range of this invention. If the heating temperature is less than 1000 ℃ in the wire process, extracting the steel from the furnace and rough rolling causes a problem of surface defects due to severe strain increase.If it exceeds 1100 ℃, the limit and surface scale of the furnace are increased. The quality of the product is reduced.

Subsequently, the reheated steel is subjected to ball rolling. The wire rolling is an essential process in the manufacture of wire rods. Through the rolling of the wire rods, a unidirectional rolling of the wires in the wire rod causes a strain, thereby causing the formation of a collective structure, that is, a Goss structure. You can activate the creation. As a result, it is possible to impart excellent magnetism to the wire rod even by performing the hot rolling in a hot state.

It is preferable to perform the cold rolling at 900 to 1000 ° C., but if it is less than 900 ° C., the process load may cause surface defects of the wire rod, and fracture of the wire rod roll may occur. If it exceeds 1000 ° C, the strain may not be effectively caused due to the ductility increase of the wire rod during rolling.

It is preferable that the reduction ratio of the cross section is 75 to 85% when the rolling is performed. When the reduction ratio of the cross section is less than 75%, it is impossible to distribute the tissue to the magnetic wire due to insufficient strain due to the lack of strain. In excess of 85%, the excessive stretching of the wire rod tissue may increase the recrystallization force and transform the goth tissue itself.

Moreover, it is preferable to have a cooling process after the said rolling, and to cool at the speed of 0.05 degrees C / s or less. When the cooling rate exceeds 0.05 ° C / s, low-temperature tissue in the tissue appears to be more likely to transform into ferrite tissue.

After the cooling step, it is preferable to perform annealing treatment, and the annealing treatment is preferably performed by heating the completed wire rod at a rate of 5 to 15 ° C./s and maintaining it at 700 to 800 ° C. for 5 to 10 minutes. The annealing process is important for generating more goth tissue in the steel sheet in the hot rolled state because the annealing treatment can impart a driving force to change direction toward the goth tissue through the other directional tissues around the goth tissue. It becomes a process.

On the other hand, if the quenching rate is less than 5 ℃ / s, the thermal expansion during heating is low due to too slow heating rate, the thermal expansion rate to the tissue may be slow, if it exceeds 15 ℃ / s due to too fast heating rate It is possible that not enough heat can be transferred inside the organization. In addition, when the annealing temperature is less than 700 ℃, there is a possibility that a pearlite is generated, if it exceeds 800 ℃, the tissue itself may be transformed into austenite. In order to implement the effect of the annealing process preferably, annealing is preferably performed for 5 to 10 minutes.

After the annealing treatment, the wire is preferably cooled to 150 ° C at a rate of 10 ° C / s or less. When the cooling rate exceeds 10 ° C / s, there is a possibility that a low temperature structure is generated due to the rapid cooling rate, by cooling to 150 ° C, wire packaging is possible.

After the annealing treatment, the surface of the wire rod may be coated with at least one member selected from the group consisting of MgO, Al ₂ O ₃ , ZnO, and ZrO _2. The materials are representative materials having insulating properties. It can react with the surface oxide layer of the steel sheet produced during annealing to form a glassy film that improves interlayer insulation and can promote the removal of sulfur that inhibits magnetism.

The wire rod of the present invention can be produced by drawing a wire rod that has been subjected to the above-described rolling, annealing and surface treatment process using a coating agent instead of a conventional wire lubricant. As the fresh lubricant, that is, the coating agent, at least one selected from the group consisting of MgO, Al ₂ O ₃ , ZnO, and ZrO ₂ is preferably used. As described above, by coating the coating agent on the surface of the wire rod, The effect of using the coating can be manifested, reducing the manufacturing time and at the same time reducing the manufacturing cost. On the other hand, the wire drawing process may be carried out without surface treatment after the wire rolling and annealing treatment, even in this case, since the coating agent is used instead of the existing fresh lubricant, it can have an effect similar to the surface treatment. . The drawing process may be performed under ordinary conditions, and the drawing material manufactured by the manufacturing method may have a Goth structure fraction of 97.5 to 99.5 area% and a saturation magnetic flux density of 300 to 300 emu.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are only for illustrating the present invention in more detail, but the scope of the present invention is not limited.

(Example 1)

The steel having a composition component of Table 1 below was prepared as a wire using the process conditions described in Table 2, and then surface coated with MgO. After measuring the fraction of the goose structure and the saturation magnetic flux density for the wire rod prepared above, the results are shown in Table 3 below. The annealing time during the production of the wire was 5 minutes.

division Chemical composition (% by weight) C Si Mn P S Al N Comparison 1 0.011 6.5 1.3 0.010 0.007 0.006 0.002 Comparative material 2 0.02 6.1 1.2 0.010 0.007 0.006 0.002 Comparative material 3 0.015 6.1 1.3 0.010 0.007 0.006 0.002 Comparison 4 0.017 6.3 1.03 0.010 0.007 0.006 0.002 Inventory 1 0.0068 6.0 0.985 0.010 0.007 0.011 0.002 Inventory 2 0.0071 6.1 0.996 0.010 0.007 0.01 0.002 Invention 3 0.0065 6.2 0.98 0.010 0.007 0.01 0.002 Invention 4 0.0074 8.1 1.02 0.010 0.007 0.013 0.002 Invention Article 5 0.0081 8.3 1.1 0.010 0.007 0.011 0.002 Comparative material 5 0.0041 11.02 1.3 0.010 0.007 0.02 0.002 Comparative material 6 0.003 11.4 1.3 0.010 0.007 0.021 0.002 Comparative Material7 0.003 10.92 1.0 0.010 0.007 0.024 0.002 Comparative Material 8 0.003 10.75 1.1 0.010 0.007 0.02 0.002

division Heating temperature
(℃) Nominal rolling temperature
(℃) Section reduction rate
(%) Cooling rate
(° C / s) Annealing temperature
(℃) Cooling rate
(° C / s) Cooling stop temperature (℃) Comparison 1 1100 850 40 0.2 850 15 150 Comparative material 2 1100 900 50 0.2 850 15 150 Comparative material 3 1100 900 60 0.1 650 20 150 Comparison 4 1100 900 70 0.15 650 20 150 Inventory 1 1100 900 75 0.05 700 5 150 Inventory 2 1100 900 75 0.03 700 5 150 Invention 3 1100 900 80 0.03 750 10 150 Invention 4 1100 900 85 0.01 800 10 150 Invention Article 5 1100 900 85 0.01 800 10 150 Comparative material 5 1100 900 40 0.2 850 15 150 Comparative material 6 1100 900 50 0.2 850 15 150 Comparative Material7 1100 900 60 0.1 650 20 150 Comparative Material 8 1100 1050 65 0.15 650 20 150

division Goth tissue fraction (area%) Saturated magnetic flux density (emu) Comparison 1 90.3 260.7 Comparative material 2 90.5 265.2 Comparative material 3 91.3 266.6 Comparison 4 91.2 266.1 Inventory 1 95.2 287.8 Inventory 2 98.2 295.5 Invention 3 96.6 281.1 Invention 4 97.7 293.3 Invention Article 5 98.1 286.5 Comparative material 5 83.2 255.1 Comparative material 6 82.2 258.3 Comparative Material7 88.1 261.9 Comparative Material 8 86.1 259.5

As can be seen in Tables 1 to 3, Inventive Materials 1 to 5 in accordance with the present invention can be seen that has a goose structure of 95% or more and a saturation magnetic flux density of 270emu or more.

However, the comparative materials 1 to 8 do not satisfy the component system and manufacturing conditions proposed by the present invention, it can be seen that it has a low level of goth structure and saturation magnetic flux density, accordingly, the comparative materials 1 to 8 are magnetic properties It can be seen that this is not excellent.

(Example 2)

After the wire rods were prepared by drawing the wire rods, the magnetic properties of the wire rods were measured, and the results are shown in Table 4 below. At this time, MgO coating was used instead of fresh lubricant.

division Goth tissue fraction (area%) Saturated magnetic flux density (emu) Comparison 1 91.0 264.4 Comparative material 2 91.2 269.2 Comparative material 3 92.0 270.6 Comparison 4 91.9 270.1 Inventory 1 97.5 310.8 Inventory 2 99.4 319.1 Invention 3 97.8 303.6 Invention 4 98.9 316.8 Invention Article 5 99.3 309.4 Comparative material 5 98.9 258.9 Comparative material 6 82.9 262.2 Comparative Material7 88.8 265.8 Comparative Material 8 86.8 263.4

As can be seen in Table 4, it is shown that the new wire, that is, the invention materials 1 to 5 manufactured to meet the present invention has excellent magnetic properties. However, it can be seen that the comparative materials 1 to 8 are inferior in synergistic effect of the magnetic properties, and the goth tissue fraction and saturation magnetic flux density which are finally obtained are also low compared to the invention materials.

Claims (12)

By weight, C: 0.005 to 0.01%, Si: 3.0 to 10.0%, Mn: 0.1 to 2.0%, Al: 0.008 to 0.018%, N: 0.0015 to 0.0030%, balance Fe and other unavoidable impurities, 95 Wire rod with excellent magnetic properties including ~ 98.5 area percent goth tissue.
The wire rod of claim 1, wherein the saturation magnetic flux density of the wire rod is 270 to 310 emu.
By weight, C: 0.005 to 0.01%, Si: 3.0 to 10.0%, Mn: 0.1 to 2.0%, Al: 0.008 to 0.018%, N: 0.0015 to 0.0030%, balance Fe and other unavoidable impurities, 97.5 Wire rod with excellent magnetic properties including ~ 99.5 area percent goth tissue.
4. The wire rod according to claim 3, wherein the saturation magnetic flux density of the wire rod is 300 to 330 emu.
1000% steel, consisting of C: 0.005 to 0.01%, Si: 3.0 to 10.0%, Mn: 0.1 to 2.0%, Al: 0.008 to 0.018%, N: 0.0015 to 0.0030%, balance Fe and other unavoidable impurities A heating step of heating at ˜1100 ° C .;
A ball rolling step of rolling the heated steel by wire;
An annealing treatment step of annealing the wire-rolled wire; And
Method of producing a wire having excellent magnetic properties comprising a surface coating step of coating a coating on the surface of the annealing the wire.
The method of manufacturing a wire rod according to claim 5, wherein the step of rolling the mold is performed at 900 to 1000 ° C.
The method of manufacturing a wire rod having excellent magnetic properties according to claim 5, wherein the step of rolling is performed at a reduction ratio of 75 to 85%.
The method of manufacturing a wire rod having excellent magnetic properties according to claim 5, wherein the wire rod is cooled at a rate of 0.05 ° C./s or less after the step of rolling.
The method of claim 5, wherein the annealing treatment is performed by heating the wire-rolled wire at a rate of 5 to 15 ° C./s for 5 to 10 minutes at 700 to 800 ° C. 7.
The method of claim 5, wherein after the annealing treatment step, the annealing wire is cooled to 150 ° C. at a rate of 10 ° C./s or less.
The method of claim 5, wherein the coating agent is at least one member selected from the group consisting of MgO, Al ₂ O ₃ , ZnO, and ZrO ₂ .
A magnetic wire comprising a drawing step of drawing a wire produced by the method of any one of claims 5 to 11 using at least one drawing lubricant selected from the group consisting of MgO, Al ₂ O ₃ , ZnO and ZrO ₂ . Method for producing wire rods with excellent properties.