Method for efficiently preparing Fe-Co-V alloy thin strip

Abstract

The embodiment of the application discloses a kind of high-efficiency preparation methods of Fe-Co-V alloy ribbon.The method includes the following processes: alloy smelting-forging-hot rolling-welding-hot composite rolling-quenching-welding into roll-cold rolling-shearing joint, wherein, the welding process is: the slab Fe-Co-V alloy obtained by hot rolling is welded into joint with easy welding alloy, the thickness of the slab Fe-Co-V alloy, easy welding alloy and joint is guaranteed to be consistent, and the length of the joint is greater than or equal to 60 mm.By introducing the plate type structure joint, combined with the mode of hot composite rolling, the Fe-Co-V alloy hot-rolled plate in fast cooling disordered state is connected into a roll from a single piece, which can avoid problems such as rolling cracking and strip breakage caused by directly welding Fe-Co-V alloy, realize the coiling rolling of Fe-Co-V alloy, and has good economy and practicability.

Description

TECHNICAL FIELD

[0001] The embodiment of the application relates to the alloy rolling processing technical field, in particular to a high-efficiency preparation method of Fe-Co-V alloy thin strips. BACKGROUND

[0002] Fe-Co-V alloy (1J22 alloy) is an alloy with excellent soft magnetic properties. Its high saturation magnetic induction strength brings great advantages to the reduction of alloy part volume and weight under the premise of constant magnetic demand. By using Fe-Co-V alloy to replace Fe-Si alloy, the weight can be reduced by 20-25% under the condition of ensuring performance requirements, so it is widely used in fields that need to consider the weight and volume of parts, such as aviation, aerospace, navigation, military and high-end civilian fields. In addition, Fe-Co-V alloy has high Curie temperature and excellent high-temperature mechanical properties, which makes the alloy have good high-temperature stability and still has good soft magnetic properties and mechanical properties in high-temperature environments where other soft magnetic materials have failed. At the same time, Fe-Co-V soft magnetic alloy also has the advantages of high magnetic permeability, low magnetic loss and low coercivity.

[0003] The Fe-Co-V alloy (1J22 alloy) widely used in the prior art has excellent soft magnetic properties, and its application mode is mainly thin strips, which are used to manufacture core, shielding shell and other core electromagnetic devices. However, due to its poor mechanical properties at room temperature, the processing and forming difficulty is increased, and thus the processing efficiency and yield are low, which greatly limits its large-scale application.

[0004] The reason for the poor mechanical properties of Fe-Co-V alloy (1J22 alloy) is related to its intrinsic characteristics. Fe-Co-V alloy undergoes secondary phase transformation at 730 DEG C, i.e. Fe-Co order-disorder transition. Above this temperature, intermetallic compound Fe-Co (alpha phase) changes from B2 structure (i.e. typical CsCl type structure) precipitated at low temperature to disordered bcc structure at high temperature. The order-disorder transition is a secondary phase transition, and the order degree changes continuously when the temperature is lower than the order-disorder transition temperature. The order degree of Fe-Co alloy has a significant impact on the performance of the alloy. The completely disordered structure of Fe-Co alloy shows excellent mechanical properties, but the magnetic properties are slightly poor. At the same time, the completely ordered structure of the alloy shows excellent magnetic properties, but the mechanical properties are poor, and it is difficult to be cold processed. In engineering applications, the order degree of the alloy is controlled by different heat treatment processes to obtain different soft magnetic properties.

[0005] When Fe-Co-V alloy is cooled from high-temperature disordered state, it will rapidly undergo an ordered transformation, but when the cooling speed is fast enough, the alloy can maintain the disordered structure at high temperature, and thus the alloy can retain good plasticity for subsequent cold working. In the actual industrial production of Fe-Co-V alloy thin strips, the technical route adopted is smelting-forging-hot rolling-quenching-cold rolling. Among them, the hot rolling and cold rolling processes are the key processes that determine the processing efficiency and yield of the thin strips. In the existing technology, the disordered structure of the alloy is preserved by rapid cooling during the hot rolling process to improve the processing performance of the alloy, and the cold working deformation of the thin strips is realized during the subsequent cold rolling process.

[0006] Since the ordering transformation speed of Fe-Co-V alloy is extremely fast, only when the cooling speed is increased to a certain extent can the disordered structure be preserved. The existing technology performs fast cooling by reducing the volume of the alloy slab and lowering the temperature of the cooling medium. However, as the volume of the slab decreases, the strip can only be processed in a single piece rather than in a multi-piece welded form, resulting in a significant decrease in processing efficiency.

[0007] In order to improve the processing efficiency of the strip, people have tried to weld the disordered alloy plates into a roll in a multi-piece welding manner for continuous cold rolling. However, the Fe-Co-V alloy has poor weldability, and the brittle transformation during welding makes it difficult to ensure continuous processing during the cold rolling deformation stage, often resulting in cracking near the weld and strip breakage, which greatly reduces the yield of the alloy strip. SUMMARY

[0008] Therefore, the embodiments of the present application provide an efficient preparation method for Fe-Co-V alloy thin strips, which utilizes the reversible nature of the ordering-disordering transformation of Fe-Co-V alloy to hot composite roll the head and tail of thick blank Fe-Co-V alloy with easily weldable material, uses easily weldable alloy as connecting material to form an easily weldable material / Fe-Co-V / easily weldable material layered composite joint, and then performs ice salt water quenching after hot rolling to the cold strip blank specification to maintain the disordered state of the Fe-Co-V alloy. The multi-piece strips are connected into a roll by welding the easily weldable material joint, thereby realizing large roll rolling of Fe-Co-V alloy.

[0009] To achieve the above object, the embodiments of the present application provide the following technical solutions:

[0010] A preparation method for Fe-Co-V alloy thin strips, comprising the following steps: alloy smelting-forging-hot rolling-welding-hot composite rolling-quenching-welding into a roll-cold rolling-joint shearing, wherein the welding step is to weld the slab Fe-Co-V alloy obtained by hot rolling and the easily weldable alloy into a joint, the thickness of the slab Fe-Co-V alloy, the easily weldable alloy, and the joint is guaranteed to be consistent, and the length of the joint is greater than or equal to 60 mm.

[0011] Further, the easy-to-weld alloy is a soft magnetic alloy with similar composition, such as pure Fe, Fe-Ni alloy or Fe-Si alloy.

[0012] The welding process is wire filling welding, and the welding voltage is 30-48V, and the welding current is 220-280A.

[0013] Further, the slab Fe-Co-V alloy and the easy-to-weld alloy are processed by wire cutting, and the welding section is Z-shaped.

[0014] Further, in the alloy smelting process, the Fe-Co-V alloy is smelted by a vacuum induction furnace, and is poured into an ingot, and the tapping temperature is 1520-1535℃.

[0015] Further, in the forging process, the alloy ingot after smelting is forged by a fast forging machine, the forging temperature is 1150-1200℃, and the alloy ingot is forged into a flat blank with a size of 85*(190-270)mm.

[0016] Further, in the hot rolling process, the hot rolling temperature is 1100-1200℃, and the hot rolling deformation is greater than or equal to 50%.

[0017] Further, the hot composite rolling temperature is 1100-1200℃, the single pass deformation is 33-40%, and the finish rolling temperature is above 780℃.

[0018] Further, the specific operation of the quenching is that the hot-rolled plate is quickly quenched in ice salt water in an inclined manner, the ice salt water temperature is controlled to be 0-10℃, and the hot-rolled plate is taken out after complete cooling.

[0019] Further, the specific operation of the cold rolling is that the plate is cold-rolled to a thickness of 1.0mm-2.0mm by using a twenty-roll rolling mill.

[0020] Further, in the shearing joint process, the shearing position is not less than 200mm away from the joint.

[0021] The embodiment of the present application has the following advantages:

[0022] (1) The present application introduces a plate type structure joint, the plate type structure joint and the slab Fe-Co-V alloy form a Z-shaped composite surface of the welding section, combined with the hot composite rolling mode, and a plurality of Fe-Co-V alloy hot-rolled plates in fast cooling disordered state are connected into a roll through the joint, which can avoid the problems of rolling cracking and belt breaking caused by directly welding the Fe-Co-V alloy, realizes the roll rolling of the Fe-Co-V alloy, and has good economy and practicability.

[0023] (2) The heat compounding process of the present application has simple production process, high efficiency, excellent and stable performance, and is suitable for large-scale production of Fe-Co-V alloy strip. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only exemplary, and other drawings can be obtained by the provided drawings without creative labor for those skilled in the art.

[0025] Figure 1 The preparation process flow chart of the Fe-Co-V alloy thin strip provided by the present application is shown in the figure.

[0026] Figure 2 The schematic diagram of the welding section provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0027] The embodiments of the present application are described below by specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the description. Obviously, the described examples are part of the examples of the present application, not all. Based on the examples in the present application, all other examples obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0028] Example 1

[0029] (1) Alloy smelting: vacuum induction furnace is used to smelt Fe-Co-V alloy, and 500 kg ingot is poured at a tapping temperature of 1530℃. The alloy ingot after smelting is deoxidized to form a bright surface.

[0030] (2) Forging: the alloy ingot after smelting is forged by using a quick forging machine, the forging temperature is 1150℃, and the forged square billet is formed into 85x198mm flat billet. Milling is used to grind the surface of the forged square billet to remove the oxide skin and other defects formed during forging.

[0031] (3) Hot rolling: the forged flat billet is hot rolled at a temperature of 1120℃, and multi-pass rolling is used to reach the final design thickness. After the final pass rolling, it is rapidly cooled at a speed greater than air cooling.

[0032] (4) Welding: the joint uses a pure Fe alloy which is easy to weld, and the thickness is consistent with that of the Fe-Co-V hot rolled plate. The welding section diagram is shown in the figure. Figure 2Fe-Co-V hot-rolled plate and the joint are processed by wire cutting, connected by hot composite welding, welding voltage is 32V, and welding current is 260A.

[0033] (5) Hot composite rolling: the Fe-Co-V hot-rolled plate and the joint connected by welding are rolled by a hot rolling mill, rolling temperature is 1120℃, single pass deformation is 35%, and final rolling temperature is 820℃.

[0034] (6) Quenching: after rolling, the single hot-rolled plate is quickly quenched in ice-salt water in an inclined manner, ice-salt water temperature is controlled to be 0-10℃, and the single hot-rolled plate is taken out after complete cooling.

[0035] (7) Welding into a roll: the oxide skin generated during quenching is removed, and multiple Fe-Co-V strips are welded into a roll through the welding joint.

[0036] (8) Cold rolling: the large roll Fe-Co-V alloy strip after welding is cold-rolled by a twenty-roller mill.

[0037] (9) Joint shearing: the strip roll is sheared by an automatic shearing machine, and the welding joint is cut off, and the shearing position is not less than 200mm away from the joint.

[0038] (10) Delivery: the thin strip without the joint is rolled, and oil-proof moisture-proof paper is laid between the strips.

[0039] The large roll Fe-Co-V alloy strip obtained in step (8) is observed, and there is no cracking, strip breaking and other phenomena near the welding joint, rolling efficiency is 90-100kg / h, and Fe-Co-V alloy yield is 60-70%.

[0040] Example 2

[0041] (1) Alloy smelting: the Fe-Co-V alloy is smelted by a vacuum induction furnace, and is poured into a 500kg ingot, and the tapping temperature is 1530℃. The alloy ingot after smelting is finished is subjected to surface oxide skin removal to form a bright surface.

[0042] (2) Forging: the alloy ingot after smelting is forged by a quick forging machine, forging temperature is 1180℃, and the ingot is forged into an 85×248mm flat blank, and the surface of the forged square blank is polished by milling, and the oxide skin and other area defects formed during forging are removed.

[0043] (3) Hot rolling: the flat blank after forging is hot-rolled, hot rolling temperature is 1180℃, and multi-pass rolling is adopted to reach the final design thickness. After final pass rolling, rapid cooling is performed at a speed greater than air cooling.

[0044] (4) Welding: the joint adopts an easy-to-weld alloy Fe-Ni alloy, the thickness is consistent with that of the Fe-Co-V hot-rolled plate, and a welding section view is as shown inFigure 2 Fe-Co-V hot-rolled plate and joint were processed by wire cutting, connected by hot composite welding, welding voltage 38V, welding current 220A.

[0045] (5) Hot composite rolling: Fe-Co-V hot-rolled plate and joint connected by welding were rolled by hot rolling mill, rolling temperature 1180℃, single pass deformation 35%, finish rolling temperature 800℃.

[0046] (6) Quenching: after rolling, single hot-rolled plate was quickly put into ice-salt water in an inclined way for quenching, ice-salt water temperature was controlled at 0-10℃, and the plate was taken out after complete cooling.

[0047] (7) Welding into coil: after removing the oxide skin generated during quenching, multiple Fe-Co-V strips were welded into a coil through the welding joint.

[0048] (8) Cold rolling: the large coil of Fe-Co-V alloy strips after welding was cold-rolled by a twenty-roller mill.

[0049] (9) Joint shearing: the strip coil was sheared by an automatic shearing machine, and the welding joint was cut off, the shearing position was not less than 200mm away from the joint.

[0050] (10) Delivery: the thin strips without joint were coiled, and oil-based moisture-proof paper was laid between the strips.

[0051] The large coil of Fe-Co-V alloy strips obtained in step (8) was observed, and there was no cracking, strip breaking and other phenomena near the welding joint, the rolling efficiency was 90-100kg / h, and the Fe-Co-V alloy yield was 60-70%.

[0052] Comparative Example 1

[0053] The preparation method of Fe-Co-V alloy thin strips provided in the comparative example is different from that of Example 1, and the processing procedure of the comparative example is: alloy smelting-forging-hot rolling-quenching-cold rolling.

[0054] (1) Alloy smelting: the Fe-Co-V alloy was smelted by a vacuum induction furnace, and poured into a 500kg ingot with a tapping temperature of 1530℃. The alloy ingot after smelting was subjected to surface oxide removal to form a bright surface.

[0055] (2) Forging: the alloy ingot after smelting was forged by a quick forging machine at a forging temperature of 1150℃, and was forged into a 85×248mm flat blank. The surface of the forged square bar was polished by milling to remove the oxide skin and other defects formed during forging.

[0056] (3) Hot rolling: hot rolling the forged flat blank at a temperature of 1120°C using multi-pass rolling to reach the final designed thickness. After the final pass, the blank is rapidly cooled at a higher rate than air cooling.

[0057] (4) Quenching: after rolling, the single hot rolled sheet is rapidly immersed into ice-salt water at an angle, and the water temperature is controlled at 0-10°C. After complete cooling, the sheet is taken out.

[0058] (5) Cold rolling: the welded single Fe-Co-V alloy strip is cold rolled by a 20-roll mill.

[0059] (6) Delivery: the thin strip is coiled, and oil-proof moisture-proof paper is laid between the strips.

[0060] In the step (6) of the comparative example 1, the rolling speed is slow, the rolling efficiency is 50-60 kg / h, and the yield of the Fe-Co-V alloy is 40-50%.

[0061] Although the present application has been described in detail by the general description and specific examples above, some modifications or improvements can be made on the basis of the present application, which is obvious to those skilled in the art. Therefore, these modifications or improvements made on the basis of not deviating from the spirit of the present application, are within the scope of the present application.

Claims

1. A method for producing a Fe-Co-V alloy thin strip, characterized by, The preparation method comprises the following steps: alloy smelting, forging, hot rolling, welding, hot composite rolling, quenching, welding into a roll, cold rolling and joint shearing, wherein the welding process is as follows: the joint is made of a weldable alloy, the joint and the slab Fe-Co-V alloy form a Z-shaped composite surface of the welded cross section, the thickness of the slab Fe-Co-V alloy, the weldable alloy and the joint is guaranteed to be consistent, and the length of the joint is greater than or equal to 60 mm. The weldable alloy is an Fe-Ni alloy or an Fe-Si alloy. The temperature of the hot composite rolling is 1100-1200 DEG C, the single-pass deformation is 33-40%, and the final rolling temperature is higher than 780 DEG C.

2. The preparation method of the Fe-Co-V alloy thin strip according to claim 1, wherein the welding process is wire filling welding, the welding voltage is 30-48 V, and the welding current is 220-280 A.

3. The preparation method of the Fe-Co-V alloy thin strip according to claim 1, wherein the slab Fe-Co-V alloy and the weldable alloy are processed by wire cutting. In the alloy smelting process, the Fe-Co-V alloy is smelted by a vacuum induction furnace, and is poured into an ingot, and the tapping temperature is 1520-1535 DEG C. In the forging process, the alloy ingot after smelting is forged by a fast forging machine, the forging temperature is 1150-1200 DEG C, and the ingot is forged into a flat blank with a size of 85 mm* (190-270) mm.

4. The method of producing a Fe-Co-V alloy thin strip according to claim 1, characterized by, In the hot rolling process, the hot rolling temperature is 1100-1200 DEG C, and the hot rolling deformation is greater than or equal to 50%.

5. The method of producing a Fe-Co-V alloy thin strip according to claim 1, characterized by, The quenching process is that the hot rolled plate is quickly put into ice salt water in an inclined manner for quenching, the ice salt water temperature is controlled to be 0-10 DEG C, and the plate is taken out after complete cooling.

6. The method of producing a Fe-Co-V alloy thin strip according to claim 1, characterized by, 8. The preparation method of the Fe-Co-V alloy thin strip according to claim 1, wherein the cold rolling process is that the plate is cold rolled to a thickness of 1.0-2.0 mm by a twenty-roller rolling machine.

7. The method of producing a Fe-Co-V alloy thin strip according to claim 1, characterized by, In the joint shearing process, the shearing position is not less than 200 mm away from the joint. ​ ​ 9. The method of producing a Fe-Co-V alloy thin strip according to claim 1, characterized by, ​

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