CN107710352B

CN107710352B - Ultra-thin wide band of iron-based nanocrystalline alloy and manufacturing method thereof

Info

Publication number: CN107710352B
Application number: CN201680003709.4A
Authority: CN
Inventors: 李宗臻; 周少雄; 张广强; 董帮少; 高慧
Original assignee: Advanced Technology and Materials Co Ltd
Current assignee: Advanced Technology and Materials Co Ltd
Priority date: 2016-05-27
Filing date: 2016-05-27
Publication date: 2020-02-18
Anticipated expiration: 2036-05-27
Also published as: CN107710352A; WO2017201749A1

Abstract

An ultra-thin wideband of iron-based nanocrystalline alloy and a manufacturing method thereof. The expression of the ultrathin broadband is as follows: fe_xSi_aB_bP_cNb_dCu_eM_fWherein M is at least one of Sn and Al, x, a, b, c, d, e and f are atomic percentages of corresponding elements, a is more than or equal to 0.5 and less than or equal to 10, b is more than or equal to 0.5 and less than or equal to 12, c is more than or equal to 0.5 and less than or equal to 8, d is more than or equal to 0.1 and less than or equal to 3, e is more than or equal to 0.1 and less than or equal to 1, f is more than or equal to 0.001 and less than or equal to 0.05, and x + a + b + c + d +. The method adopts an improved plane flow casting method to manufacture the belt, the bandwidth of the prepared ultrathin broadband is 50-200 mm, the thickness of the prepared ultrathin broadband is 0.001-0.02 mm, the transverse thickness deviation of the belt is less than +/-0.0015 mm, the lamination coefficient is greater than 0.80, the saturation magnetic flux density is greater than 1.7T, and the iron loss is less than 0.30W/kg under the conditions that the frequency is 50Hz and the maximum magnetic flux density is 1.5T.

Description

Ultra-thin wide band of iron-based nanocrystalline alloy and manufacturing method thereof

Technical Field

The invention belongs to the field of magnetic functional materials, and particularly relates to an iron-based nanocrystalline alloy ultrathin broadband and a preparation method thereof, in particular to a nanocrystalline ultrathin broadband with a bandwidth of 50-200 mm, a saturation magnetic flux density of more than 1.7T, and an iron loss of less than 0.30W/kg under the conditions of a frequency of 50Hz and a maximum magnetic flux density of 1.5T.

Background

The iron-base nanometer crystal soft magnetic material consists of amorphous matrix and α -Fe (Si) crystal grains distributed on the matrix in nanometer size, and the size of the crystal grains is smaller than the exchange coupling length, so that the magnetic crystal anisotropy is effectively reduced.

In recent years, the energy and environmental problems are increasingly serious, the rapid development of the power electronic technology puts higher requirements on the energy efficiency and stability of electrical equipment, the application field of the nanocrystalline magnetically soft alloy is continuously expanded, and the demand is rapidly increased. Especially, in the aspects of high-efficiency motors and reactors, higher requirements are put forward on the saturation induction strength of the nanocrystalline strip and the strip broadband. However, the saturation induction density of the commercially available nanocrystalline alloy (Finemet) is only 1.24T, while the saturation induction density of the commercially available silicon steel sheet is about 2T, the saturation induction density of the iron-based nanocrystalline alloy is relatively low, and the bandwidth is generally less than 50mm, so that the development requirements of miniaturization and high energy efficiency are difficult to meet.

Japanese patent JP1156451A discloses a nanocrystalline alloy of high saturation induction expressed as FeCoCuSiBM ', wherein M' represents one or more elements of Nb, W, Ta, Zr, Hf, Ti, and the volume fraction of the crystal phase is maintained at 50% or more by controlling the heat treatment regime so that the saturation induction of the alloy is 1.4T or more, which is actually a way of controlling the heat treatment, more α -Fe crystal grains are precipitated to have high B content of α -Fe itself_sThe saturation magnetic induction intensity of the alloy is improved. However, this method has limited potential for promotion, the highest B exemplified_sOnly at 1.58T.

Chinese patent CN101834046 discloses an expression of Fe_xSi_yB_zP_aCu_bThe nanocrystalline alloy has a saturation magnetic induction intensity of 1.9T and excellent soft magnetic performance.However, the amorphous forming ability of the component is poor, high-density nanometer crystal nuclei are generated in the preparation process, the subsequent crystallization heat treatment needs to adopt rapid annealing to obtain a nanometer double-phase structure with excellent performance, the annealing time cannot exceed 5min, otherwise the soft magnetic performance is rapidly deteriorated, so that the annealing process of the component is difficult to control, and the industrial production is difficult.

Chinese patent CN1450570 discloses a nanocrystalline soft magnetic alloy ultra-thin strip and a preparation method thereof: provides a chemical composition of iron-based nanocrystalline magnetically soft alloy and a production process of an ultrathin strip. The alloy comprises the following chemical components in percentage by mass: 0.1-0.2% of Si, 6-8% of Zr, 4-6% of Nb, 0.1-1% of Al, 1-2% of B, 1-1.5% of Cu and the balance of Fe. The production process comprises the steps of preparing master alloy by induction melting, then carrying out plane flow casting (linear velocity of 40-70m/s) in Ar atmosphere to spray amorphous strips, and finally carrying out magnetic field heat treatment at 400-600 ℃ for 30-60 minutes under the vacuum condition. The best soft magnetic properties of the resulting alloy strip are: saturation magnetic induction is 1.7T, and coercive force is 9.6A/m. Although the saturation induction strength of the component reaches 1.7T, the component needs to be sprayed in a protective atmosphere, and large-scale industrial production is difficult to realize.

The mainstream tape making technology for commercial amorphous and nanocrystalline alloys is a planar flow casting method, and the typical manufacturing process is as follows: melting metal raw materials with specific components, flowing molten steel onto a metal cooling roller which rotates at high speed and has good heat conductivity through a nozzle slit with the width of less than 1mm, spreading the molten steel into a stable molten pool on the outer circumferential surface of the cooling roller, and contacting the molten pool at the bottom of the molten pool with the roller surface by 10 DEG C⁶Rapidly cooling at a rate of about 0.03 mm/sec to form a continuous thin metal strip having a thickness of about 0.03 mm. The bandwidth of the amorphous strip prepared by the plane flow casting method is determined by the length of a nozzle slot, and the thickness of the amorphous strip is mainly determined by three factors of the width size of the nozzle slot, the stability of a weld pool and the surface quality of a cooling roller. When the amorphous alloy strip is manufactured, the size of the nozzle slot determines the flow rate of the mother alloy molten steel, so that the transverse width uniformity (namely the nozzle slot length direction) of the nozzle slot is one of the keys of the transverse thickness uniformity of the amorphous alloy strip. Transverse disturbance and melting of laminar molten steel in weld poolPuddle instability can increase the roughness of the free surface of the strip and the depth of the scratch, thereby indirectly affecting the thickness of the strip. The roughness of the surface of the cooling roll is directly reflected on the roll surface of the strip and also influences the flatness of the strip, thereby indirectly influencing the thickness of the strip.

The invention patent US19970864892 provides a nozzle structure for amorphous alloy wide band manufacturing, by special nozzle profile design, amorphous alloy wide band with a maximum width of 200mm and uniform transverse thickness can be obtained. Chinese patent ZL99808439.5 discloses a method for manufacturing amorphous strips with the width of 170mm, which can manufacture iron-based amorphous wide bands with the width of 170mm and the lamination coefficient of about 90% by controlling the surface roughness of a cooling roller to be less than 0.005mm and controlling the surface roughness of a nozzle seam to be less than 0.005 mm. However, if a wider amorphous alloy broadband is manufactured, the overlong nozzle is easy to deform due to the large temperature gradient at the nozzle, so that the transverse thickness consistency of the amorphous alloy broadband is affected, the lamination coefficient of the amorphous alloy broadband is seriously reduced, and the nozzle is cracked even by the thermal stress in serious conditions, so that the requirement of manufacturing the high-quality iron-based amorphous alloy broadband with the width of more than 220mm cannot be met.

Currently, the amorphous broadband is commercially produced, for example, iron-based amorphous alloy strip products (1K101) produced by the ontai technologies ltd have three width specifications of 142mm, 170mm and 213mm, and are used for transformer cores with different sizes. The prior art can produce Fe-based amorphous alloy strips with width no more than 213mm, but the width of the commercially available nanocrystalline strips (1k107) is generally less than 50 mm. The amorphous alloy contains about 20 percent of Si and B metal elements, the alloy melt has larger amorphous forming capability and good fluidity, the nanocrystalline alloy melt contains a large amount of Nb elements and has very high viscosity, so the fluidity is very poor, the strip manufacturing is difficult, the nanocrystalline wide strip is designed and manufactured by utilizing the amorphous alloy strip with the prior specification, the melt fluidity can be increased only by greatly increasing the strip spraying pressure and increasing the strip spraying temperature, the excessive pressure can cause the nozzle to deform and even cause the nozzle to crack, the excessive strip spraying temperature can cause excessive impurities in the molten metal, the risk of steel leakage is increased, and the technology is not feasible. Due to the energy-saving benefit and excellent high-frequency performance of the nanocrystalline alloy distribution transformer, the nanocrystalline alloy is urgently expected to be used as an iron core material in large-scale transformers, reactors and motors. Therefore, the strip of the nanocrystalline alloy with a larger bandwidth and a higher saturation induction is required to be manufactured to take advantage of the advantages of the nanocrystalline alloy, and particularly, a great demand is put on an ultra-thin broadband of the iron-based nanocrystalline alloy with a width of more than 50 mm.

Disclosure of Invention

Aiming at the defects and shortcomings in the prior art, the invention aims to provide an iron-based nanocrystalline alloy ultrathin broadband and a manufacturing method thereof, wherein the width of the nanocrystalline alloy broadband is 50-200 mm, the saturation induction intensity is greater than 1.7T, the surface flatness of a strip is high, the toughness after annealing is good, and the high-frequency loss is low.

In order to achieve the purpose, the invention provides the following technical scheme:

the ultrathin iron-based nanocrystalline alloy broadband comprises a component expression of Fe_xSi_aB_bP_cNb_dCu_eM_fWherein M in the expression is Sn and/or Al; in the expression, x, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component and satisfy the following conditions: a is more than or equal to 0.5 and less than or equal to 10, b is more than or equal to 0.5 and less than or equal to 12, c is more than or equal to 0.5 and less than or equal to 8, d is more than or equal to 0.1 and less than or equal to 1, e is more than or equal to 0.1 and less than or equal to 3, f is more than or equal to 0.001 and less than or equal to 0.05, and x + a + b + c +.

In the ultrathin broadband iron-based nanocrystalline alloy, as a preferred embodiment, the value range of the atomic percent content x of the component Fe is 82-83.

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage content a of the component Si is in a range of 1 ≦ a ≦ 6 (e.g. 1.2, 2, 3, 4, 5, 5.8).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage content B of the component B is in a range of 2 ≦ B ≦ 7 (e.g. 2.1, 3, 4, 5, 6, 6.8).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage content c of the component P is in a range of 2 ≦ c ≦ 5 (e.g. 2.1, 2.5, 3, 4, 4.5).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage content d of the component Nb is in a range of 0.5 ≤ d ≤ 0.75 (e.g. 0.55, 0.6, 0.65, 0.7, 0.74).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage content e of the component Cu is in a range of 0.5 ≤ e ≤ 0.75 (such as 0.55, 0.6, 0.65, 0.7, and 0.74).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the atomic percentage f of the component M is in a range of 0.01 ≤ f ≤ 0.05 (e.g., 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045).

In the ultra-thin wide band of the iron-based nanocrystalline alloy, as a preferred embodiment, the width of the ultra-thin wide band is 50 to 200mm, the thickness of the ultra-thin wide band is 0.001 to 0.02mm, the thickness deviation in the transverse direction (i.e., the width direction of the ultra-thin wide band) is less than ± 0.0015mm, the lamination coefficient is greater than 0.80, the saturation magnetic flux density is greater than 1.7T, and the iron loss is less than 0.30W/kg under the conditions that the frequency is 50Hz and the maximum magnetic flux density is 1.5T.

The following explains the principle of designing the components of the iron-based nanocrystalline magnetically soft alloy:

in the iron-based nanocrystalline alloy of the present invention, the atomic% of Si element is satisfied: 0.5. ltoreq. a.ltoreq.10, with a.ltoreq.1.ltoreq.6 being preferred. Si is a common element for forming amorphous alloy, and the proper amount of Si can not only improve the thermal stability and Curie temperature of the alloy and improve the amorphous forming capability of the alloy, but also improve the solubility of B, P and other metalloid elements in the alloy and expand the component range of the alloy; when the content of atomic% of Si element is less than 0.5, the effect of promoting the formation of amorphous alloy by Si element is hardly exerted sufficiently, and when the content of atomic% of Si element is more than 10, the content of ferromagnetic element is reduced, and a soft magnetic alloy with high saturation induction cannot be obtained.

In the iron-based nanocrystalline alloy of the present invention, the atomic% of B element satisfies 0.5. ltoreq. b.ltoreq.12, and the preferable range is 5. ltoreq. b.ltoreq.8. When the B atomic% is less than 0.5, the content of the B element is too low, and a precursor of the nanocrystalline alloy, that is, an amorphous alloy is not easily formed. When the atomic% of B is more than 12, the content of ferromagnetic elements in the alloy is reduced to lower the saturation induction of the alloy.

In the iron-based nanocrystalline alloy of the present invention, the atomic% of the P element is satisfied: 0.5. ltoreq. c.ltoreq.8, with a preferred range of 2. ltoreq. c.ltoreq.5. The P element is a common element for forming the amorphous alloy, the P element is added in a proper amount, the P and other elements in a system have larger negative mixed heat, and the addition of the P element is beneficial to improving the stability of a supercooled liquid phase region, so that the amorphous forming capability of the alloy can be improved, the thermal stability of the alloy can be improved, and the range of a thermal treatment temperature region of the amorphous alloy can be enlarged. When the content of the P element atom% is less than 0.5, the effect of the P element to promote the formation of an amorphous alloy is hardly exerted, and when the content of the P element atom% is more than 8, the content of a ferromagnetic element is reduced, and a soft magnetic alloy with high saturation induction cannot be obtained.

In the iron-based nanocrystalline alloy of the present invention, the atomic% of Nb is such that d is 0.1. ltoreq. d.ltoreq.1, and preferably in the range of 0.5. ltoreq. d.ltoreq.0.75. Nb is a large atom element and is an effective element for inhibiting the growth of a-Fe nano crystal grains, refining the crystal grains and improving the soft magnetic performance of the nano crystal. As the Nb element is a non-ferromagnetic element, when the content exceeds 1 atom percent, the content of the ferromagnetic element in the alloy is reduced, thereby reducing the saturation magnetic induction intensity. When the content of Nb is less than 0.1 atomic%, the effects of Nb on improving the amorphous forming ability, refining the crystal grains, and improving the soft magnetic properties are hardly exerted.

In the iron-based nanocrystalline alloy of the present invention, Cu element, because it is insoluble in Fe, is uniformly precipitated from the amorphous matrix during heat treatment to promote α -Fe nucleation, which is a common element for producing nanocrystalline alloys, the atomic% of Cu element is such that 0.1. ltoreq. e.ltoreq.3, preferably 0.5. ltoreq. e.ltoreq.0.75, when Cu atomic% is more than 3, the amorphous forming ability of the alloy is deteriorated and the production is difficult, and when Cu atomic% is less than 0.1, Cu acts as promotion α -Fe nucleation during annealing, and the effect of forming nanocrystalline alloys is difficult to exert.

In the iron-based nanocrystalline alloy, the component M is one or any combination of two of surface active elements Al or Sn, and the addition of trace surface active elements Al and Sn greatly reduces the surface tension of a melt, and maintains the stability of the melt through the interaction of the melt and the surface tension.

In the above iron-based nanocrystalline magnetically soft alloy, a small amount of inevitable impurity elements may be contained, but the total weight percentage of all impurity elements is less than 0.5%.

A manufacturing method of the iron-based nanocrystalline alloy ultrathin broadband adopts a planar flow casting process and comprises the following steps:

preparing raw materials according to a composition expression of the alloy ultrathin broadband, and then melting the raw materials by adopting induction melting under a protective gas atmosphere and carrying out overheating treatment to form molten steel with uniform components;

step two, pouring the molten steel into a tundish for sedation and carrying out molten steel purification treatment;

pouring the molten steel in the tundish into a nozzle ladle, then enabling the molten steel to flow to the surface of a cooling roller rotating below a nozzle from a nozzle slot of the nozzle arranged on the bottom surface of the nozzle ladle, and rapidly cooling the molten steel to form the iron-based amorphous alloy ultrathin broadband;

and step four, carrying out heat treatment on the iron-based amorphous alloy ultrathin broadband to obtain the iron-based nanocrystalline alloy ultrathin broadband.

In the above manufacturing method, as a preferred embodiment, in the fourth step, the heat treatment time is 5-120min (e.g., 6min, 20min, 30min, 50min, 80min, 90min, 110min), and the heat treatment temperature is 400-.

In the above manufacturing method, as a preferred embodiment, in the third step, the ultra-thin iron-based amorphous alloy ribbon obtained after cooling is synchronously wound into a ribbon coil by a winding machine.

Specifically, the iron-based nanocrystalline alloy broadband adopts a planar flow casting method with improved technology and a traditional isothermal annealing treatment method, the basic technological process comprises the steps of material preparation and mother alloy smelting, molten steel calming and purifying treatment, amorphous alloy broadband high-speed continuous casting, alloy broadband online coiling and isothermal annealing treatment, and the technological process is shown in figure 1.

For the iron-based nanocrystalline alloy broadband of the present invention, pure iron, ferroboron, ferrosilicon, ferroniobium, ferrophosphorus, copper ingot, aluminum ingot, and tin ingot can be used as raw materials for mother alloy smelting, and the raw materials are melted and subjected to overheating treatment in an induction furnace or other type of smelting furnace 1 to form molten steel with uniform components. Then, the molten steel is poured into the tundish 2. The tundish plays a role in buffering the production rhythm, allows the molten steel to be calmed for a certain time, and can allow inclusions in the molten steel to fully float upwards by matching with other metallurgical means in the prior art, thereby improving the quality of the master alloy molten steel. The killed and purified mother alloy molten steel is poured into a nozzle ladle 3, a nozzle 7 is arranged at the bottom of the nozzle ladle 3, and the nozzle 7 comprises a long and narrow nozzle slot 71 and a weld pool accommodating part 78 positioned below the nozzle slot, so that the molten steel flows out and is protected. A copper alloy cooling roller 4 rotating at a high speed is arranged below the nozzle seam, the steel liquid is spread into a uniform film immediately after flowing to the surface of the cooling roller and is rapidly cooled into an amorphous alloy strip, the strip is synchronously coiled into a strip coil 6 by a coiling machine 5, and the iron-based nanocrystalline alloy broadband is obtained after heat treatment.

In the above manufacturing method, as a preferred embodiment, in the step one, the temperature of the overheating treatment is not lower than 1500 ℃ (for example, 1500 ℃, 1550 ℃, 1600 ℃, 1660 ℃, 1700 ℃), and the time of the overheating treatment is not less than 10min (for example, 11min, 13min, 15min, 18min, 20min, 30min, 50min, or 60 min).

In the above manufacturing method, as a preferred embodiment, in the second step, the temperature of the molten steel being killed is 1250-. Preferably, the silicon oxide and the rare earth are selected as the purifying agent main bodies, and the calcium oxide and the silicon-manganese alloy are selected as the purifying agents of the stabilizing agents, so that molten steel is purified after molten steel in the tundish reaches the calming temperature. In the purification process, the impurities of oxides, nitrides, sulfides and the like with lower density are not melted in the molten steel, are adsorbed by the same-quality purifying agent, and continuously float and polymerize on the surface layer of the molten steel. The slag layer covers the surface of the molten steel, the atmosphere and the molten steel are isolated, the molten steel is prevented from being directly contacted with O, N, and the burning loss of elements Si and B is reduced. More preferably, in the scavenger, the silica content is 20 to 35 wt%; the calcium oxide can not only deoxidize, but also remove S in the molten steel, and the content of the calcium oxide is 7-20 wt%; the silicon-manganese alloy is mainly used for deoxidation, in addition, the existence of Mn can effectively remove an impurity element S, the S is almost an impurity element which is necessarily contained in ferroboron, silicon and an iron source and is easy to cause brittleness of an amorphous strip, the existence of Mn can form a MnS low-melting-point compound with S in molten steel to float upwards and enter a slag layer, so that the desulfurization effect is achieved, and the content of the silicon-manganese alloy (such as 6517) is 10-20 wt%; the rest is rare earth; finally, the O, S, N content in the molten steel is controlled below 10 ppm.

In the above manufacturing method, as a preferred embodiment, in the third step, the nozzle is a puddle embedded nozzle, including:

the nozzle comprises a nozzle body, a nozzle body and a nozzle body, wherein the nozzle body is provided with a molten steel accommodating part and is used for receiving and buffering molten steel from the nozzle pack;

the nozzle slot is arranged on the lower bottom surface of the nozzle body and is used for ejecting the molten steel in the nozzle body; and

weld pool protection body: the molten steel nozzle is arranged below the nozzle body and connected with the nozzle body to form a weld pool accommodating part for protecting molten steel from being ejected out of a weld pool formed behind the nozzle seam.

In the manufacturing method, as a preferred embodiment, in the puddle embedded nozzle, the nozzle body includes a first nozzle body side wall, a second nozzle body side wall, a third nozzle body side wall, and a fourth nozzle body side wall, the first nozzle body side wall, the second nozzle body side wall, the third nozzle body side wall, and the fourth nozzle body side wall are sequentially connected to form a closed nozzle body peripheral wall, and the nozzle body peripheral wall and a lower bottom surface of the nozzle body enclose the molten steel containing part with an upper bottom surface opening; the first nozzle body sidewall and the third nozzle body sidewall are parallel to the length direction of the nozzle slot.

In the weld puddle in-line nozzle, as a preferred embodiment, the width of the nozzle slit is 0.05-0.3 mm (such as 0.06mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm), and more preferably, the width deviation of the nozzle slit in the transverse direction (i.e. along the length direction of the nozzle slit) is less than ± 0.025mm (such as 0.002mm, 0.005mm, 0.008mm, 0.01mm, 0.015mm, 0.018mm, 0.02mm, 0.024 mm).

In the above manufacturing method, as a preferred embodiment, in the puddle embedded nozzle, the puddle protector includes:

the front lip vertically extends downwards from the lower end surface of the side wall of the first nozzle body;

the rear lip vertically extends downwards from the lower end surface of the side wall of the third nozzle body;

the first side lip vertically extends downwards from the lower end surface of the side wall of the second nozzle body;

the second side lip vertically extends downwards from the lower end surface of the side wall of the fourth nozzle body;

the front lip, the first side lip, the rear lip and the second side lip are sequentially connected to form the weld puddle accommodating part with an opening at the lower bottom surface.

In the above manufacturing method, as a preferred embodiment, the shape of the weld pool accommodating portion is the same as or close to the shape of the weld pool formed after the molten steel is ejected from the nozzle slit.

In the above manufacturing method, as a preferred embodiment, the inner wall of the rear lip is inclined from top to bottom and the wall thickness of the rear lip gradually decreases from top to bottom. More preferably, the inner wall of the rear lip is arranged in a linear inclined mode or an arc inclined mode.

In the above manufacturing method, as a preferred embodiment, the shape of the lower end surface of the front lip is the same as the shape of the corresponding cooling roll surface; the shape of the lower end face of the rear lip is the same as that of the corresponding cooling roller surface; the shape of the lower end face of the first side lip is the same as that of the corresponding cooling roller surface; the shape of the lower end face of the second side lip is the same as the shape of the corresponding cooling roller surface.

In the above manufacturing method, as a preferable embodiment, the height of the front lip is not lower than the height of the rear lip; preferably, the height of the front lip is higher than the height of the rear lip.

In the above manufacturing method, as a preferred embodiment, a perpendicular distance between a lower end surface of the front lip and the surface of the cooling roll is not less than 0.05mm (e.g., 0.06mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4 mm); the vertical distance between the lower end surface of the rear lip and the surface of the cooling roller is not less than 0.1mm (such as 0.11mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm and 0.4 mm); more preferably, the lower end face of the rear lip is at a perpendicular distance of 0.1 to 0.3mm from the surface of the cooling roll.

In the above manufacturing method, as a preferable embodiment, a perpendicular distance between the nozzle slit and the cooling roll surface is 0.25 mm.

In the above-described production method, as a preferred embodiment, in the third step, the nozzle is used for producing the tape by a post-injection method.

In the above manufacturing method, as a preferred embodiment, in the third step, when the nozzle is used for manufacturing the strip, the temperature of the molten steel flowing out from the nozzle (i.e. the strip spraying temperature) is 1300 to 1350 ℃ (for example 1310 ℃, 1320 ℃, 1330 ℃ or 1340 ℃), and the high-temperature strip spraying is beneficial to unpacking and increasing the fluidity of the melt.

In the above manufacturing method, as a preferred embodiment, in the third step, the transverse (i.e., width direction of the cooling roll) flatness of the cooling roll is less than 0.015 m; the surface roughness Ra of the cooling roller is always less than 0.0005 mm; preferably, the linear velocity of the outer surface of the cooling roller is 25-35 m/sec.

A nozzle is embedded nozzle of weld pool, includes:

In the case that the nozzle is a weld pool embedded nozzle, as a preferred embodiment, the nozzle body comprises a first nozzle body side wall, a second nozzle body side wall, a third nozzle body side wall and a fourth nozzle body side wall, the first nozzle body side wall, the second nozzle body side wall, the third nozzle body side wall and the fourth nozzle body side wall are sequentially connected to form a closed nozzle body peripheral wall, and the nozzle body peripheral wall and the lower bottom surface of the nozzle body enclose the molten steel containing part with an opening at the upper bottom surface; the first nozzle body sidewall and the third nozzle body sidewall are parallel to the length direction of the nozzle slot.

In the case that the nozzle is a weld puddle in-line nozzle, as a preferred embodiment, the width of the nozzle slit is 0.05-0.3 mm (e.g., 0.06mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm), and more preferably, the width deviation of the nozzle slit in the transverse direction (i.e., along the length direction of the nozzle slit) is less than ± 0.025mm (e.g., 0.002mm, 0.005mm, 0.008mm, 0.01mm, 0.015mm, 0.018mm, 0.02mm, 0.024 mm).

Above-mentioned nozzle is in the embedded nozzle of weld pool, as an preferred embodiment in the embedded nozzle of weld pool, the weld pool protection body includes:

In the nozzle which is a weld puddle embedded nozzle, as a preferred embodiment, the shape of the weld puddle accommodating part is the same as or close to that of the weld puddle formed after molten steel is ejected out of the nozzle slot.

In the case that the nozzle is a weld puddle embedded nozzle, as a preferred embodiment, the inner wall of the rear lip is inclined from top to bottom and the wall thickness of the rear lip gradually decreases from top to bottom. More preferably, the inner wall of the rear lip is arranged in a linear inclined mode or an arc inclined mode.

In the case that the nozzle is a weld puddle embedded nozzle, as a preferred embodiment, the shape of the lower end surface of the front lip is the same as the shape of the corresponding cooling roll surface; the shape of the lower end face of the rear lip is the same as that of the corresponding cooling roller surface; the shape of the lower end face of the first side lip is the same as that of the corresponding cooling roller surface; the shape of the lower end face of the second side lip is the same as the shape of the corresponding cooling roller surface.

In the case that the nozzle is a weld pool embedded nozzle, as a preferred embodiment, the height of the front lip is not lower than that of the rear lip; preferably, the height of the front lip is higher than the height of the rear lip.

In the case that the nozzle is a weld pool embedded nozzle, as a preferred embodiment, the vertical distance between the lower end surface of the front lip and the surface of the cooling roller is not less than 0.05mm (such as 0.06mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4 mm); the vertical distance between the lower end surface of the rear lip and the surface of the cooling roller is not less than 0.1mm (such as 0.11mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm and 0.4 mm); more preferably, the lower end surface of the rear lip is at a vertical distance of 0.1 to 0.3mm from the cooling roll.

In the case that the nozzle is a weld puddle embedded nozzle, as a preferred embodiment, the vertical distance between the nozzle gap and the surface of the cooling roller is 0.25 mm.

In the above-described nozzle being a puddle-embedded nozzle, as a preferred embodiment, the thickness of the front lip is not less than the thickness of the sidewall of the first nozzle body.

In the case where the nozzle is a puddle-embedded nozzle, as a preferred embodiment, the thickness of the upper end of the rear lip is not less than the thickness of the sidewall of the third nozzle body.

The weld puddle is in a dynamic balance state when the amorphous strip is prepared by the plane flow casting method, the melt entering the weld puddle from the nozzle pack and the amorphous strip extracted from the bottom of the weld puddle reach dynamic balance, and the stable production of the amorphous strip can be continued. The plane flow casting process of the invention can be finished in the atmosphere without special atmosphere. Nozzle slot length directly determines the bandwidth, while the nozzle slot lateral dimension uniformity also determines the amorphous broadband lateral thickness uniformity. Simultaneously, the horizontal disturbance of weld pool inner laminar flow molten steel and weld pool instability can increase the roughness of strip free surface and the degree of depth of mar to the indirect thickness that influences the strip. The surface roughness of the copper roller can be directly reflected to the roller-attaching surface of the strip, the flatness of the strip can be influenced, and the thickness of the strip can be indirectly influenced. The uniformity and cleanliness of the melt directly influence the fluidity of the melt and the difficulty and stability of the strip spraying process. In order to obtain the nanocrystalline ultrathin broadband, the method regulates and controls the melt state, the nozzle size, the puddle stability and the cooling roll surface state on the basis of the traditional plane flow casting method, and the specific implementation scheme is as follows:

1) controlling the homogeneity of the melt, namely molten steel: structural inheritance exists in the alloy melt, and the non-uniformity of the alloy melt can cause the instability of the performance of the final product. The liquid-liquid structure phase change of the nanocrystalline alloy melt in a high-temperature overheating area exists, and the liquid-liquid phase change temperature of the alloy melt with different components is between 1350-1450. Therefore, in order to obtain a highly uniform alloy melt, the melting temperature in the melting furnace must be set to 1500 ℃ or higher to sufficiently dissolve the poorly soluble crystal nuclei and the macromolecular clusters in the melt.

2) Controlling nozzle seam: control of the range of the nozzle slit width W: d is more than or equal to 0.05mm and less than or equal to 0.3 mm. The mouth seam is more than 0.3mm, so that a thin strip with the thickness less than 20 microns is difficult to obtain; the nozzle seam is less than 0.05mm, the molten metal is difficult to flow out of the nozzle due to the action of surface tension, and trace impurity particles in the molten steel are accumulated at the nozzle, so that the amorphous alloy broadband is divided into strips. An important condition for obtaining thin strips of 1-20 μm thickness is therefore that the width of the nozzle slot cannot be too wide and must be limited to less than 0.3 mm. When the nozzle gap of the nozzle is relatively wide, the rotating speed of the cooling roller is increased to reduce the thickness of the strip appropriately, but the rotating speed of the cooling roller is increased too much to increase the roughness of the surface of the strip and the depth of surface scratches. Typically, the mouth gap is between 0.3mm and 1.2 mm, and the thickness of the amorphous strip which can be obtained is only 20-60 microns. That is, the nozzle gap is too wide, and the belt thickness cannot be effectively reduced no matter how the rotating speed of the cooling roller is adjusted or the distance between the roller nozzles is reduced.

3) Control of nozzle shape and configuration: according to the invention, the lower end face of the front lip of the nozzle is almost tightly attached to the roller surface, and the height of the rear lip of the nozzle is slightly higher than that of the front lip, namely the distance between the lower end face of the rear lip and the roller surface is larger than that between the lower end face of the front lip and the roller surface. In addition, the present invention requires that the lateral width deviation of the nozzle slit be less than ± 0.025 mm. Experiments show that if the transverse width deviation of the nozzle slot is larger than +/-0.025 mm, the transverse width deviation has certain influence on the uniformity of the molten steel flow, so that the thickness uniformity of the broadband is slightly poor, and the lamination coefficient of the produced broadband is slightly poor.

4) Controlling the shape and stability of the weld puddle: firstly, the invention adopts a weld pool embedded nozzle, and the weld pool is positioned in the nozzle, thereby greatly reducing the impact of airflow caused by the movement of a cooling roller on the weld pool; in addition, the invention greatly reduces the viscosity of the nanocrystalline alloy and increases the fluidity and the mold filling capacity of the alloy melt by reasonably designing the components, particularly, the addition of trace surface active elements Al and Sn greatly reduces the surface tension of the melt, and the stability of the melt is maintained through the interaction of the melt and the surface tension.

5) The control of the strip spraying mode is realized by adopting a post-spraying method to carry out strip spraying, the cooling stroke of a strip on a cooling roller is greatly increased, the strip stripping temperature is reduced, meanwhile, a weld pool embedded nozzle is adopted, the weld pool is positioned in a nozzle weld pool accommodating part, the distance between the rear lip of the nozzle and the lower end face of the weld pool is very small, the scraping pressure and the correcting action are formed on the free surface of the weld pool, the transverse disturbance of the amorphous alloy strip to laminar molten steel is reduced, the surface stress of the strip is reduced, and the surface quality of the amorphous strip and the stability of the performance of a finished product are improved.

6) Control of the cooling roll rotation speed: under the condition of a certain unit flow of the nozzle, the stretching rate of the nozzle can be increased by increasing the roller speed, but the thickness of the strip is reduced limitedly, the pull mark on the surface of the strip is too large, the surface roughness is increased, even a reticular structure and holes are formed, and the quality is seriously reduced. Therefore, the cooling roller speed generally cannot be too high, and the linear speed is less than 35 m/s.

7) Controlling the flatness and the roughness of the surface of the cooling roller: if the surface of the cooling roller has transverse or longitudinal undulation, the thickness of the amorphous alloy broadband is obviously influenced to be consistent in the transverse or longitudinal direction, and the thickness of the strip is indirectly influenced. Experiments show that in order to enable the lamination coefficient of the amorphous alloy broadband to reach more than 80%, the transverse flatness deviation of the surface of the cooling roller must be ensured to be less than 0.015mm, and the high-flatness cooling roller surface can be realized by a commercially available high-precision turning device. In the continuous casting process of the amorphous alloy strip, the surface quality of the roller is gradually deteriorated due to the fact that the surface of the cooling roller continuously bears the erosion and thermal shock of molten steel, and the pit-shaped defect occurs. In order to eliminate the defects of the roll surface in time, the roll surface needs to be continuously cleaned and repaired by adopting a commercially available online efficient roll surface repairing device.

8) Control of an ultrathin broadband receiving mode: since the continuous casting speed of the amorphous alloy strip is as high as about 20m/sec, the produced alloy strip must be coiled in synchronization with the continuous casting process of the strip, or the strip is rapidly piled up, not only making the coiling inefficient in the later period, but also forming a large amount of wrinkles in the strip, thereby easily breaking and lowering the lamination factor. By adopting the automatic coiling device, the synchronous coiling of the alloy strip is realized, and the mass continuous production of the amorphous alloy strip is realized.

Compared with the prior art, the invention has the beneficial effects that:

1) the invention breaks through the limitation of the original nanocrystalline soft magnetic alloy strip on the alloy components and develops a new alloy system. The Fe-based nanocrystalline magnetically soft alloy ultrathin broadband with high saturation magnetization and strong amorphous forming capability is prepared by component design. The large reduction of Nb element and the large addition of P element improve the amorphous forming ability, reduce the viscosity of molten steel, increase the fluidity and the mold filling ability of molten alloy and greatly reduce the production cost of materials.

2) The invention adds trace surface active elements into the alloy, can greatly reduce the surface tension of the melt during the strip-spraying without reducing the viscosity of the melt, and improves the stability of the weld puddle by adjusting the shape and the size of the weld puddle by coordinating the interaction of the surface tension and the viscosity of the melt, thereby achieving the requirement of stabilizing the strip-spraying. The invention adds at least one component of Al and Sn with the atomic ratio of 0.001-0.05 percent on the basis of the existing alloy components, greatly reduces the surface tension of the alloy melt, reduces the difficulty of producing and unpacking the nanocrystalline alloy strip and increases the stability of the weld puddle on the premise of not damaging the soft magnetic performance of the alloy, thereby improving the flatness of the free surface of the strip and greatly improving the production process of the strip and the product quality stability.

3) The invention adopts a three-pack method to prepare the strip, adopts a smelting furnace to carry out high-temperature smelting (the highest smelting temperature is more than 1500 ℃), a tundish is calmed at a low temperature (lower than 1300 ℃), and a nozzle pack carries out higher-temperature strip spraying (higher than 1300 ℃). The high-temperature smelting of the smelting furnace can improve the uniformity of molten steel to the maximum extent and reduce endogenous impurities. The low-temperature sedation of the tundish can remove the impurities which are continuously precipitated due to the reduction of the temperature to the maximum extent, the higher-temperature strip spraying of the nozzle ladle avoids the new emergence of the regenerated impurities, simultaneously reduces the viscosity of the melt, increases the fluidity of the molten steel, and is beneficial to reducing the difficulty of ladle opening and the strip breakage phenomenon caused by the blockage of the impurities. The temperature control system of the molten steel in each stage of the three-ladle method can be independently adjusted according to requirements, so that inclusions generated in the production flow of the molten steel can be removed to the maximum extent in each production flow, the cleanliness of the molten steel is improved, and the production cost is reduced.

4) According to the invention, the embedded type weld pool nozzle is adopted, the front lip of the nozzle is tightly attached to the surface of the roller, and the weld pool is positioned in the weld pool accommodating part of the nozzle, so that the influence of airflow for cooling the surface layer of the roller on the weld pool is reduced, and the stability of the weld pool is improved. The existing nozzle weld puddle is exposed in the air and is rapidly cooled under the influence of the airflow on the surface layer of the rotating cooling roller, the temperature is seriously reduced, in addition, the nozzle is required to be exposed so as to be close to the cooling roller to form a necessary weld puddle shape, and the exposed plane of the nozzle is rapidly cooled on the surface of the rapidly rotating cooling roller. If the temperature of the nozzle needs to be kept, the molten metal which continuously flows through the nozzle has a heating effect on the nozzle, and even a complex flame curtain weld pool protection technology is adopted to balance the lost heat of the nozzle and the heat supplement of the molten metal to the nozzle, so that the technical difficulty is high, and the effect is poor. Therefore, the prior art can not ensure that the sprayed amorphous strip has bright surface, thickness of 1-20 microns and high filling coefficient.

5) The invention controls the width of the nozzle slot of the nozzle, emphasizes the range of the width W of the nozzle slot: d is more than or equal to 0.05mm and less than or equal to 0.30 mm. Thin strips with the thickness of less than 20 microns cannot be obtained when the nozzle seam is larger than 0.30 mm, thick strips with the thickness of more than 20 microns are generally obtained, and even if the strips with the thickness of about 20 microns are obtained, the roughness of the surface of the strips is large, the surfaces of the strips are not smooth, and the use value is not large. An important condition for obtaining ultra-thin strips of 1-20 microns thickness is therefore that the width of the nozzle slot cannot be too wide and must be limited to less than 0.30 mm.

6) The invention uses the on-line automatic coiling mechanism to collect the strip, so that the strip obtained in the above steps can be coiled into a coil in a state of being always tensioned, the thin strip does not generate wrinkles, the core can be coiled subsequently by using the automatic iron core winding device, the core can be smoothly cut in the subsequent longitudinal and transverse cutting processes of the strip without breaking, and the high filling coefficient of the core is ensured. This is also an important condition for manufacturing a high-quality iron core. However, in the prior art, because a high-quality thin strip cannot be obtained, the thin strip cannot be automatically coiled on line, but is directly peeled off to the ground and then collected. And a lot of wrinkles and damages are generated in peeling, falling to the ground, moving and collecting the strip, thereby deteriorating the quality and magnetic properties of the processed core.

7) The amorphous ultrathin broadband can be subjected to heat treatment in a traditional heat treatment furnace to obtain the ultrathin nanocrystalline broadband with excellent soft magnetic performance, the heat treatment time is 5-120min, the heat treatment temperature is 400-600 ℃, the heat treatment temperature region is wide, the soft magnetic performance cannot be deteriorated after long-time heat treatment, in addition, the heat treatment can be carried out in the atmosphere, and the method is particularly suitable for industrial production.

8) The 1-8 strips have the combined action, can better produce the uniform nanocrystalline ultrathin broadband with high quality, high surface smoothness and 1-20 microns thickness, the production and annealing process of the invention is simple, the cost is low, the industrialization is easy to realize, and the prepared product has excellent soft magnetic performance and high filling coefficient and is applied to the fields of electric power, electronics, information, communication and the like.

The bandwidth of the ultrathin broadband prepared by the method is 50-200 mm, the thickness of the ultrathin broadband is 0.001-0.02 mm, the transverse thickness deviation of the strip is less than +/-0.0015 mm, the lamination coefficient is greater than 0.80, the saturation magnetic flux density is greater than 1.7T, and the iron loss is less than 0.30W/kg under the conditions that the frequency is 50Hz and the maximum magnetic flux density is 1.5T.

Drawings

FIG. 1 is a schematic view of the process principle of the ultra-thin broadband manufacturing method of iron-based nanocrystals of the present invention;

FIG. 2 is a side cross-sectional view of a conventional nozzle;

FIG. 3 is a side cross-sectional view of a weld puddle in-line nozzle of the present invention;

FIG. 4 is a bottom view of a weld puddle embedded nozzle of the present invention;

FIG. 5 shows Fe in example of the present invention_82.5Si₄B₈P₄Nb_0.7Cu_0.75Al_0.02Sn_0.03Quenching XRD pictures of the alloy in all amorphous strips with different thicknesses.

FIG. 6 shows Fe in an example of the present invention_82.5Si₄B₈P₄Nb_0.7Cu_0.75Al_0.02Sn_0.03TEM picture of alloy full amorphous strip annealed at 560 ℃ for 30 minutes;

wherein the reference numbers are as follows: 1. a smelting furnace; 2. a tundish; 3. a nozzle pack; 4. a cooling roll; 5. a coiler; 6. a coil of strip material; 7. nozzle, 71, 71', nozzle slot; 72. the posterior lip; 73. the anterior lip; 74. a first side lip; 75. a second side lip; 76. the inner side of the posterior lip; 77. a molten steel accommodating part; 78. a weld pool accommodating part; 79', a first nozzle body sidewall; 79 ", a second nozzle body sidewall; 8. molten steel; 9. a thin strip; 10. and (5) cooling the roller.

Detailed Description

The following detailed description of embodiments of the present invention is provided in connection with the accompanying drawings and examples.

The invention provides an embedded nozzle 7 with a weld pool as a nozzle, comprising: a nozzle body for receiving and buffering molten steel from the nozzle pack 3; a nozzle slot 71 arranged on the lower bottom surface of the nozzle body and a weld pool protecting body used for protecting a weld pool formed after the molten steel 8 is sprayed out of the nozzle slot 71. The above components are described one by one below.

A nozzle body formed with a molten steel receiving part 77 for receiving and buffering molten steel from the nozzle pack 3. The upper end surface of the nozzle body is fixed at a molten steel outlet of the nozzle pack 3.

The nozzle body comprises a first nozzle body side wall 79 ', a second nozzle body side wall (not shown), a third nozzle body side wall 79', and a fourth nozzle body side wall (not shown), wherein the first nozzle body side wall 79 ', the second nozzle body side wall, the third nozzle body side wall 79' and the fourth nozzle body side wall are sequentially connected to form a closed nozzle body peripheral wall, and the nozzle body peripheral wall and the lower bottom surface of the nozzle body enclose a molten steel containing part 77 with an upper bottom surface opening; the first and third nozzle body sidewalls 79', 79 "are parallel to the length L direction of the nozzle slot 71. The second and fourth nozzle body sidewalls are perpendicular to the length L direction of the nozzle slot 71.

A nozzle slit 71 provided on a lower bottom surface of the nozzle body for ejecting the molten steel 8 in the nozzle body; the width W of the nozzle seam is 0.05-0.3 mm, and more preferably, the width deviation of the nozzle seam in the transverse direction (namely along the length L direction of the nozzle seam) is less than +/-0.025 mm (such as 0.002mm, 0.005mm, 0.008mm, 0.01mm, 0.015mm, 0.018mm, 0.02mm and 0.024 mm).

Weld pool protection body: and a weld pool accommodating part 78 is formed below and connected with the nozzle body and used for protecting a weld pool formed after molten steel is ejected out of the nozzle slot 71. The weld pool protection body comprises a front lip 73, a rear lip 72, a first side lip 74 and a second side lip 75, wherein the front lip 73, the first side lip 74, the rear lip 72 and the second side lip 75 are sequentially connected to form a weld pool accommodating part 78 with an open lower bottom surface. Wherein: a front lip 73 formed to extend vertically downward from a lower end surface of the first nozzle body side wall 79'; a rear lip 72 formed to extend vertically downward from a lower end surface of the third nozzle body side wall 79 "; a first side lip 74 formed to extend vertically downward from the lower end surface of the side wall of the second nozzle body; a second side lip 75 formed to extend vertically downward from the lower end surface of the side wall of the fourth nozzle body; the front lip 73 and the rear lip 72 are parallel to the length L of the mouth slit 71. The first and third side lips 74, 75 are perpendicular to the length L of the mouth slit 71. Weld pool accommodating part 78 forms the guard action to the molten steel, has reduced the air current on chill roll top layer to the influence of weld pool, has improved the stability of weld pool, prevents its rapid cooling. The prior nozzle structure is shown in fig. 2, which only comprises a nozzle body and a nozzle gap 71', a weld pool protective body is arranged below the nozzle body, the weld pool is exposed in the air and is rapidly cooled under the influence of airflow on the surface layer of a rotating cooling roller, the temperature reduction is serious, in addition, the nozzle is required to be exposed so as to be close to the cooling roller to form a necessary weld pool shape, and the exposed plane of the nozzle is rapidly cooled on the surface of the rapidly rotating cooling roller. In the prior art, if the temperature of the nozzle needs to be maintained, molten metal which continuously flows through the nozzle needs to have a heating effect on the nozzle, and even a complex flame curtain weld puddle protection technology is adopted to balance lost heat of the nozzle and heat supplement of the molten metal to the nozzle, so that the technical difficulty is high, and the effect is poor. The nozzle provided by the invention is provided with the weld puddle protection body, so that the technical problem in the existing nozzle can be well solved.

In the present invention, the front lip 73 and the rear lip 72 are relative to the moving direction of the cooling roller, and after the cooling roller is turned on, the front lip 73 passes through the lowest point of the cooling roller which is rotated to the vicinity of the nozzle first in the stationary state, and the rear lip 74 passes through the nozzle later.

The shape of the puddle receiving portion 78 is close to or the same as the shape of a puddle formed behind the molten steel discharge nozzle slit 71. Preferably, the inner wall of the rear lip 72 is obliquely arranged from top to bottom and the wall thickness of the rear lip 72 is gradually reduced from top to bottom. More preferably, the inner wall of the rear lip 72 is inclined in a straight line or inclined in an arc line. The shape of the lower end surface of the front lip 73 is the same as the surface shape of the corresponding cooling roll 10; the shape of the lower end surface of the rear lip 72 is the same as the surface shape of the corresponding cooling roll 10; the shape of the lower end surface of the first side lip 74 is the same as the surface shape of the corresponding cooling roller 10; the shape of the lower end surface of the second side lip 75 is the same as the surface shape of the corresponding cooling roll 10. That is, the lower end surface of the weld pool protective body is parallel to the surface of the cooling roll, and the front lip mainly stops the gas driven by the surface of the cooling roll from being involved in the weld pool when the cooling roll rotates at a high speed, so that the thickness of the front lip 73 is not less than the thickness of the side wall 79' of the first nozzle body, and preferably, the thicknesses of the front lip and the first nozzle body are the same. The rear lip 72 mainly has the functions of scraping the free surface of the weld pool and correcting the transverse disturbance of the flowing molten steel, so that the corresponding shape of the rear lip 72 is close to the free surface of the rear end of the weld pool, preferably, the inner wall of the rear lip 72 is obliquely arranged from top to bottom, and the wall thickness of the rear lip 72 is gradually reduced from top to bottom; more preferably, the inner wall of the rear lip 72 is inclined in a straight line type or inclined in an arc line type; further, the thickness of the upper end of the rear lip 72 is not less than the thickness of the third nozzle body side wall 79 ". Therefore, the impact of the melt on the rear lip 72 can be reduced, the weld pool free surface is better scraped and pressed, and the transverse disturbance of the laminar molten steel is better corrected, so that the thin strip 9 with uniform thickness and low surface roughness is formed.

The height of the front lip 73 (i.e., the distance from the lower bottom surface of the nozzle body to the lower end surface of the front lip) is not lower than the height of the rear lip (i.e., the distance from the lower bottom surface of the nozzle body to the lower end surface of the rear lip); preferably, the height of the front lip is higher than the height of the rear lip. The vertical distance between the lower end surface of the front lip 73 and the surface of the cooling roller 10 is not less than 0.05mm (such as 0.06mm, 0.08mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm and 0.4mm), and the roller is easily scratched when the front lip is too close to the roller surface; the vertical distance between the lower end surface of the rear lip 72 and the surface of the cooling roller 10 is not less than 0.1mm (such as 0.11mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4 mm); more preferably, the lower end face of the rear lip 72 is at a perpendicular distance of 0.1 to 0.3mm from the surface of the cooling roll 10. If the rear lip is too high, for example, the distance between the rear lip and the roller mouth is the same, the rear lip of the nozzle cannot scrape the free surface of the weld puddle and has a correcting effect on the transverse disturbance of the flowing molten steel. The lower end faces of the first side lip 74 and the second side lip 75 are not less than 0.05mm from the surface immediately below the cooling roll 10.

When the nozzle of the present invention is used, the nozzle slit 71 is preferably spaced from the cooling roll surface by a vertical distance of 0.25 mm.

The following is a detailed description of the preparation of the alloy ultra-thin strip of the present invention.

Example 1

In the chemical composition range of the iron-based amorphous alloy, 6 different iron-based amorphous alloy components with the serial numbers of 1-6 are respectively selected, and a nanocrystalline alloy broadband is manufactured by using a planar flow casting process, wherein the main process parameters are as follows:

(1) pure iron, ferroboron, ferrosilicon, ferroniobium, ferrophosphorus, copper ingot, aluminum ingot and tin ingot are used as raw materials for smelting master alloy, the raw materials are prepared according to the expression of each alloy in table 1, and the raw materials are melted and subjected to overheating treatment in an induction furnace or a smelting furnace 1 in other modes under the protection of argon gas to form molten steel with uniform components. The smelting temperature is 1400 ℃, the smelting time is 30min, the overheating treatment is carried out at 1550 ℃ after the steel is hydrated and cleared, and the overheating time is 20min, so that uniform molten steel is obtained.

(2) Then pouring the smelted molten steel into a tundish, and keeping the temperature at 1280 ℃. After the temperature of the molten steel reaches a set temperature, a purifying agent which takes silicon oxide and rare earth as a purifying agent main body and calcium oxide and silicon-manganese alloy as a stabilizing agent is added to purify the molten steel, wherein the purifying agent comprises 20 wt% of silicon oxide, 15 wt% of calcium oxide, 15 wt% of silicon-manganese alloy and the balance of rare earth. The sedation time is 30min, the O, S, N content in the molten steel is monitored in real time, and after a plurality of times of sedation and slag removal, the O, S, N content is controlled below 10ppm finally.

(3) Pouring molten steel in a tundish into a nozzle ladle, spraying the molten steel to the surface of a cooling roller rotating below a nozzle from a nozzle slot of the nozzle positioned at the bottom of the nozzle ladle, and rapidly cooling to obtain the iron-based amorphous alloy ultrathin broadband, wherein the nozzle is the weld puddle embedded nozzle, the length L of the nozzle slot is 51-201mm, the width W of the nozzle slot is 0.2-0.3mm, and the width deviation of the nozzle slot in the transverse direction (along the length direction of the nozzle slot) is not more than +/-0.02 mm; the vertical distance between the lower end surface of the front lip of the nozzle and the cooling roller right below the front lip of the nozzle is 0.05mm, the vertical distance between the lower end surface of the rear lip of the nozzle and the cooling roller right below the rear lip of the nozzle is 0.15mm, and the vertical distance between the nozzle seam and the cooling roller right below the nozzle seam is 0.25 mm; the linear velocity of the cooling roller is 25m/S, the spraying temperature is 1300-.

(4) And then collecting the ultrathin amorphous broadband by an online automatic coiling mechanism so as to obtain the strip coil.

(5) And (3) placing the ultrathin amorphous broadband into a conventional heat treatment furnace, and treating at 560 ℃ for 30 min. The microstructure is characterized by an X-ray diffractometer (XRD) and a projection electron microscope, and the magnetic performance of the alloy strip is tested by conventional magnetic testing equipment.

Some specific process parameters and amorphous alloy broadband properties for each alloy number are shown in tables 1 and 1-6 in table 4, respectively.

The thickness of the iron-based nanocrystalline alloy broadband manufactured by the process of the embodiment is 0.01-0.02 mm, the transverse deviation of the broadband thickness is not more than +/-0.0015 mm, the lamination coefficient is more than 0.80, the saturation magnetic flux density is more than 1.7T, and the iron loss is less than 0.20W/kg under the conditions that the frequency is 50Hz and the maximum magnetic flux density is 1.3T.

From FIG. 5 canIt is seen that the alloy component produced is Fe_82.5Si₄B₈P₄Nb_0.7Cu_0.75Al_0.02Sn_0.03The surface of the full-glass rod is smooth and metallic, XRD only has a wide steamed bread peak which is a typical amorphous structure, and when the thickness of a strip reaches 0.05mm, the strip still keeps a typical amorphous state, which shows that the system has strong amorphous forming capability and can prepare amorphous strips with uniform quenching state structures.

As can be seen from FIG. 6, Fe_82.5Si₄B₈P₄Nb_0.7Cu_0.75Al_0.02Sn_0.03The amorphous strip is annealed at 560 ℃ for 30 minutes to form a typical nano dual-phase composite structure, and a large number of α -Fe nano particles with the diameter of about 17nm are uniformly distributed on the amorphous matrix.

Example 2

The addition of the trace surface active elements Al and Sn can greatly reduce the surface tension of a melt during strip spraying without reducing the viscosity of the melt, and the shape and the size of a weld puddle are adjusted by coordinating the interaction of the surface tension and the viscosity of the melt to improve the stability of the weld puddle, thereby achieving the purpose of improving the flatness of the free surface of a strip, reducing the unpacking difficulty and greatly improving the production process of the strip and the stability of the product quality. In the chemical composition range of the iron-based amorphous alloy, 6 different iron-based amorphous alloy components with the serial numbers of 7-12 (wherein, the alloys with the serial numbers of 7 and 11 are comparative examples) are respectively selected, and a nanocrystalline alloy broadband is manufactured by a planar flow casting process, wherein the main process parameters are as follows:

(2) Then pouring the smelted molten steel into a tundish, and keeping the temperature at 1280 ℃. After the temperature of the molten steel reaches a set temperature, adding a purifying agent which takes silicon oxide and rare earth as a purifying agent main body and calcium oxide and silicon-manganese alloy as a stabilizing agent to purify the molten steel, wherein the purifying agent comprises 20 wt% of silicon oxide, 15 wt% of calcium oxide, 15 wt% of silicon-manganese alloy and the balance of rare earth. The sedation time is 30min, the O, S, N content in the molten steel is monitored in real time, after a plurality of times of sedation and slag removal, the O, S, N content is controlled below 10ppm finally,

(3) pouring molten steel in the tundish into a nozzle ladle, spraying the molten steel onto the surface of a cooling roller rotating below a nozzle from a nozzle slot of the nozzle positioned at the bottom of the nozzle ladle, and rapidly cooling the molten steel to form the ultra-thin iron-based nanocrystalline alloy broadband, wherein the nozzle is the weld puddle embedded nozzle, the length of the nozzle slot is 151mm, the width of the nozzle slot is 0.02mm, and the deviation of the transverse width of the nozzle slot is not more than +/-0.02 mm; the vertical distance between the lower end surface of the front lip of the nozzle and the cooling roller right below the front lip of the nozzle is 0.05mm, the vertical distance between the lower end surface of the rear lip of the nozzle and the cooling roller right below the rear lip of the nozzle is 0.15mm, and the vertical distance between the nozzle seam and the cooling roller right below the nozzle seam is 0.25 mm; the linear velocity of the cooling roller is 25m/S, the spraying temperature is 1300 ℃, the spraying viscosity is 10.0-13.2 mPa.S, the surface tension of the spraying belt is 0.6-1.75N/m, the surface roughness Ra of the cooling roller is 0.00030-0.00050mm, and the transverse (namely the width direction of the roller) flatness of the surface of the cooling roller is 0.003-0.018 mm.

The specific process parameters and amorphous alloy broadband properties of the alloys of each series are shown in tables 7-12 of tables 1 and 4, respectively.

The observation of the microstructure of the strip before and after the heat treatment in the embodiment shows that the system has strong amorphous forming capability, can prepare amorphous strips with uniform quenching state structures, can form a typical nano dual-phase composite structure after isothermal annealing, and a large amount of α -Fe nano particles are uniformly distributed on an amorphous matrix.

The comprehensive embodiment shows that Al and Sn can greatly influence the preparation and the performance of the nanocrystalline ultrathin broadband. This is manifested in two ways: 1. in the aspect of melts, the addition of a proper amount of Al and Sn elements greatly reduces the surface tension of the melts, and has little influence on the viscosity of the melts, so that the difficulty of unpacking during ribbon spraying is greatly reduced while the temperature is molten; 2. in terms of magnetic performance, the addition of appropriate amounts of Al and Sn elements has little influence on saturation induction and loss, but excessive addition causes the strip to become brittle and the loss to be large.

Example 3

According to the invention, the molten pool embedded nozzle is adopted to spray the strip, the stability of the molten pool is greatly improved, the surface quality of the free surface of the strip is improved, the flow of the molten steel passing through the nozzle in unit time is controlled by adopting an ultra-narrow nozzle gap, meanwhile, a high-precision online grinding device is adopted to improve the surface quality of the strip close to the roller surface, and the three parameters are coordinated with each other to further improve the quality of the ultra-thin broadband. In the chemical composition range of the iron-based amorphous alloy, 6 different iron-based amorphous alloy components with serial numbers of 13-18 are respectively selected, and a nanocrystalline alloy broadband is manufactured by using a planar flow casting process, wherein the main process parameters are as follows:

(3) pouring molten steel in the tundish into a nozzle ladle, spraying the molten steel onto the surface of a cooling roller rotating below a nozzle from a nozzle slot of the nozzle positioned at the bottom of the nozzle ladle, and rapidly cooling the molten steel to form the ultra-thin iron-based nanocrystalline alloy broadband, wherein the nozzle is the weld puddle embedded nozzle, the length of the nozzle slot is 150mm, the width of the nozzle slot is 0.05-0.2mm, and the deviation of the transverse width of the nozzle slot is not more than +/-0.02 mm; the vertical distance between the lower end surface of the front lip of the nozzle and the cooling roller right below the front lip of the nozzle is 0.05mm, the vertical distance between the lower end surface of the rear lip of the nozzle and the cooling roller right below the rear lip of the nozzle is 0.15mm, and the vertical distance between the nozzle seam and the cooling roller right below the nozzle seam is 0.25 mm; the linear velocity of the cooling roller is 25m/s, the spraying temperature is 1320 ℃, the spraying viscosity is 10.0mPa.S, the surface tension of the spraying belt is 0.6-1.75N/m, the surface roughness Ra of the cooling roller is 0.00030-0.00050mm, and the transverse (namely the width direction of the roller) flatness of the surface of the cooling roller is 0.003-0.018 mm.

(5) And (3) placing the ultrathin amorphous broadband into a conventional heat treatment furnace, and treating at 560 ℃ for 30 min.

The microstructure is characterized by X-ray diffractometer (XRD) and projection electron microscope, and the invention is tested by conventional magnetic testing equipment

The specific process parameters and amorphous alloy broadband properties of the alloys in each series are shown as 13-18 in tables 2, 4 and 5, respectively.

The comprehensive embodiment shows that the strip spraying equipment and the process also have great influence on the preparation of the ultrathin broadband. This is manifested in two ways: 1. in terms of loss, the strip loss decreases rapidly with strip thickness. 2. In terms of strip thickness, the nozzle slot width directly determines the strip thickness. 3. In the aspect of surface quality, the use of the embedded nozzle of weld puddle greatly reduces the roughness of the surface tension of the strip, thereby effectively improving the lamination coefficient and indirectly reducing the thickness of the strip.

Example 4

By plane castingThe thickness of the prepared amorphous strip is mainly determined by three factors of the width size of a nozzle slot, the stability of a weld pool and the surface quality of a cooling roller. When the amorphous alloy strip is manufactured, the size of the nozzle slot determines the flow rate of the mother alloy molten steel, so that the transverse width uniformity of the nozzle slot is one of the keys of the transverse thickness uniformity of the amorphous alloy strip. The horizontal disturbance of weld pool inner laminar flow molten steel and weld pool instability can increase the roughness of strip free surface and the degree of depth of mar to the indirect thickness that influences the strip. The roughness of the surface of the cooling roll is directly reflected on the roll surface of the strip and also influences the flatness of the strip, thereby indirectly influencing the thickness of the strip. Thus, this example was set up with 8 comparative experiments (commercial amorphous alloy Fe)₇₈Si₉B₁₃Commercial nanocrystalline alloy Fe_73.5Cu₁Nb₃Si_13.5B₉The component Fe of the present invention_82.5Si₄B₈P₄Nb_0.7Cu_0.75Al_0.02Sn_0.03) Reference numerals 19-26, see example 1 for further processing except for some process parameters, see Table 3. The influences of the shape and the structure of the nozzle, the wide band of the nozzle gap and the roughness of the roller surface on the quality and the performance of the strip are mainly examined. The comprehensive embodiment shows that: 1. the size of the nozzle slot directly determines the molten steel flowing through the nozzle in unit time, so that the ultra-narrow nozzle slot is the premise for preparing the ultra-thin strip; 2. when the ultra-narrow nozzle seam is used for spraying the tape, the surface tension of the melt must be small, and the package can be smoothly opened; 3. the alloy components have strong amorphous forming ability to prepare the wide band; 4. adopt the embedded nozzle of weld pool can effectively reduce weld pool inner laminar flow molten steel's horizontal disturbance and weld pool instability can increase the roughness of strip free surface and the degree of depth of mar, effectively improve the quality of strip free surface. 5. And a commercially available high-precision online grinding device is adopted to improve the surface quality of the surface of the strip attached to the roller, so that the quality of the surface of the strip attached to the roller is improved. The invention breaks through the limitation of the original nanocrystalline soft magnetic alloy strip on the alloy components by optimizing the component design, develops a nanocrystalline alloy system with strong amorphous forming capability, greatly reduces the surface tension of a melt by adding trace surface active elements Al and Sn, and greatly reduces the unpacking difficulty during strip sprayingLow. And a weld puddle embedded nozzle and the roll surface are used for on-line grinding, so that the surface quality of the strip is improved, and the ultrathin nanocrystalline broadband is successfully prepared. The invention adopts an improved plane flow casting method, and has important significance for the industrial production of amorphous and nanocrystalline broadband. See table 5 for results.

The above embodiments are only for illustrating the invention and are not to be construed as limiting the invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the invention, therefore, all equivalent technical solutions also belong to the scope of the invention, and the scope of the invention is defined by the claims.

Claims

1. The ultrathin broadband of the iron-based nanocrystalline alloy is characterized in that the component expression of the ultrathin broadband of the alloy is Fe_xSi_aB_bP_cNb_dCu_eM_fWherein M in the expression is Sn and/or Al; in the expression, x, a, b, c, d, e and f respectively represent the atom percentage content of each corresponding component and satisfy the following conditions: a is more than or equal to 0.5 and less than or equal to 10, b is more than or equal to 0.5 and less than or equal to 12, c is more than or equal to 0.5 and less than or equal to 8, d is more than or equal to 0.1 and less than or equal to 3, e is more than or equal to 0.1 and less than or equal to 1, f is more than or equal to 0.001 and less than or equal to 0.05, and x + a + b + c；

The width of the ultrathin broadband is 50-200 mm, the thickness of the ultrathin broadband is 0.001-0.02 mm, the transverse thickness deviation is less than +/-0.0015 mm, the lamination coefficient is greater than 0.80, the saturation magnetic flux density is greater than 1.7T, and the iron loss is less than 0.30W/kg under the conditions that the frequency is 50Hz and the maximum magnetic flux density is 1.5T;

the manufacturing method of the ultrathin broadband of the iron-based nanocrystalline alloy comprises the following steps:

step four, carrying out heat treatment on the iron-based amorphous alloy ultrathin broadband to obtain the iron-based nanocrystalline alloy ultrathin broadband;

in step three, the nozzle is the embedded nozzle of weld pool, include:

weld pool protection body: the molten steel receiving part is arranged below the nozzle body and connected with the nozzle body to form a weld pool accommodating part for protecting a weld pool formed after the molten steel is ejected out of the nozzle seam;

the width of the mouth seam is 0.05-0.3 mm.

2. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content x of the component Fe ranges from 82 to 83.

3. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content a of the component Si ranges from 1 to 6.

4. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percentage content B of component B ranges from 2 to 7.

5. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content c of component P ranges from 2 to 5.

6. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content d of the component Nb ranges from 0.5 to 0.75.

7. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content e of the constituent Cu ranges from 0.5 to e 0.75.

8. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, characterized in that the atomic percent content f of component M ranges from 0.01 to 0.05.

9. The ultra-thin broadband of iron-based nanocrystalline alloy as claimed in claim 1, wherein in the fourth step, the heat treatment time is 5-120min, and the heat treatment temperature is 400-600 ℃.

10. The ultra-thin wideband of Fe-based nanocrystalline alloy as claimed in claim 1, characterized in that in step three, the ultra-thin wideband of Fe-based amorphous alloy obtained after cooling is immediately coiled into a wideband coil by a coiler synchronously.

11. The ultra-thin broadband of iron-based nanocrystalline alloy according to claim 1, characterized in that in said first step, the temperature of said overheating is not lower than 1500 ℃, and the time of the overheating is not less than 10 min.

12. The ultra-thin broadband of the iron-based nanocrystalline alloy as claimed in claim 1, wherein in the second step, the temperature of the molten steel is 1250-.

13. The ultra-thin broadband of iron-based nanocrystalline alloy according to claim 12, characterized in that said scavenger comprises: 20-35 wt% of silicon oxide; 7-20 wt% of calcium oxide; 10-20 wt% of silicon-manganese alloy; the rest is rare earth.

14. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 1, wherein in the puddle in-line nozzle, the nozzle body comprises a first nozzle body side wall, a second nozzle body side wall, a third nozzle body side wall and a fourth nozzle body side wall, the first nozzle body side wall, the second nozzle body side wall, the third nozzle body side wall and the fourth nozzle body side wall are sequentially connected to form a closed nozzle body peripheral wall, and the nozzle body peripheral wall and the nozzle body lower bottom surface enclose the molten steel containing part with an open upper bottom surface; the first nozzle body sidewall and the third nozzle body sidewall are parallel to the length direction of the nozzle slot.

15. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 1, wherein the mouth slit has a lateral width deviation of less than ± 0.025 mm.

16. The ultra-thin broadband of iron-based nanocrystalline alloy according to claim 14, characterized in that in the weld puddle in-line nozzle, the weld puddle protector comprises:

17. The ultra-thin broadband of the iron-based nanocrystalline alloy of claim 14, wherein the shape of the weld puddle accommodating portion is the same as or similar to the shape of a weld puddle formed after molten steel is ejected out of the nozzle gap.

18. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 16, wherein the inner wall of the rear lip is inclined from top to bottom and the wall thickness of the rear lip gradually decreases from top to bottom.

19. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 18, wherein the inner wall of the rear lip is linearly or arcuately sloped.

20. The ultra-thin wideband of iron-based nanocrystalline alloy according to claim 16, characterized in that the height of the front lip is not lower than the height of the rear lip.

21. The ultra-thin wideband of iron-based nanocrystalline alloy according to claim 20, characterized in that the height of the front lip is higher than the height of the rear lip.

22. The ultra-thin broadband of iron-based nanocrystalline alloy of claim 16, wherein the vertical distance of the lower end face of the front lip from the chill roll is not less than 0.05 mm; and the vertical distance between the lower end surface of the rear lip and the surface of the cooling roller is not less than 0.1 mm.

23. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 22, wherein the perpendicular distance between the lower end face of the rear lip and the surface of the chill roll is 0.1-0.3 mm.

24. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 1, wherein the nozzle gap is at a perpendicular distance of 0.25mm from the cooling roll surface.

25. The ultra-thin wide strip of iron-based nanocrystalline alloy of claim 1, wherein in step three, the strip is produced by the post-injection method during the strip production by the nozzle.

26. The ultra-thin wide strip of iron-based nanocrystalline alloy according to claim 1, wherein in step three, the temperature of the molten steel flowing out of the nozzle during strip production is 1300-1350 ℃.

27. The ultra-thin wide strip of iron-based nanocrystalline alloy according to claim 1, characterized in that in step three, the transverse flatness of the chill roll is less than 0.02 mm; the surface roughness Ra of the cooling roller is always less than 0.0005 mm.

28. The ultra-thin broadband of iron-based nanocrystalline alloy according to claim 1, characterized in that the linear velocity of the outer surface of the chill roll is 25 to 35 m/sec.