JP3777012B2 - Method for joining iron-cobalt alloy materials - Google Patents

Description

これに対して、同じ冷間圧延板を用いて、加速電圧７０ｋＶ、ビーム電流２０ｍＡ、溶接速度５００ｍｍ／ｍｉｎ、加工距離：３００ｍｍ、ビーム収束距離：２６０ｍｍ、ＡＣ偏向：１．０ｍｍφ、５００Ｈｚの条件下で電子ビーム溶接したところ、接合部には基材をふくめてα’相のＣｓＣ１型規則相を形成しており、以降の冷間圧延は不可能であった。
【００１８】
さらに、同じ冷間圧延板について、１．６ｍｍφタングステン電極を用い、アーク電流：４０Ａ、溶接速度：６０ｍｍ／ｍｉｎ、アルゴンガス流量：８リットル／ｍｉｎの条件下でＴＩＧ溶接したところ、溶接部から母材にかけて割れが発生し、健全な継手を得ることは不可能であった。
【００１９】
【発明の効果】
（１） 接合部に、脆弱な規則相が存在しないので、鉄−コバルト系軟磁性材料の連続冷間圧延が可能となる。
【００２０】
（２） 接合手段として、高エネルギービーム溶接法を適用することによって、溶融域は極めて少なく急冷されるので、脆弱な規則相のない接合部を得ることができる。
【００２１】
（３） 薄板の冷間圧延材の長尺での製造が可能となり、打ち抜き等の後工程への波及効果が大きく、最終製品の低コスト化、量産化が可能となる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding method for making an iron-cobalt alloy material continuous, for example, for rolling.
[Prior art]
The iron-cobalt-based alloy exhibits a large value of saturation magnetic flux density Bs of about 2.3 T or more in a region where cobalt is 25 to 60%, and particularly exhibits an excellent initial magnetic permeability at a composition of about 50% cobalt. Soft magnetic material. The magnetic properties of this alloy, particularly the high saturation magnetic flux density, are suitable for small high-performance motors, solenoid valves and actuators that require high magnetic force.
[0003]
However, this alloy is hard and brittle in the vicinity of 50% cobalt produced by the iron-cobalt ordered lattice, so that the workability is poor and cannot be subjected to processing such as ordinary cold rolling. Therefore, a 50% Co—Fe alloy containing 2% V is used to improve plastic workability.
[0004]
[Problems to be solved by the invention]
However, even with this alloy containing V, it is not possible to form a rollable joint, and for joining this alloy, as shown in JP-A-7-166239, for the continuation of thin wires, It is only disclosed that crimp welding is performed at 750 to 850 ° C. in an inert gas atmosphere.
[0005]
Since the plate material can only be rolled for each single billet for rolling with a small capacity that has been vacuum-cast, a long thin plate has not been obtained. For this reason, the final product becomes expensive, and in reality, its use is limited to a limited range such as the diaphragm of the receiver.
[0006]
Conventionally, in order to continuously perform cold rolling of this soft magnetic material, various welding methods such as ordinary steel plates have been tried. However, a large amount of molten metal exists, and slow cooling from the r-phase region. And the structure is transformed as r → α → α ′ (ordered α phase), and a fragile ordered phase appears over a considerable range in the weld and heat affected zone. Hot rolling becomes impossible.
[0007]
The subject of this invention is obtaining the joining method for enabling the cold-working of the junction part of iron-cobalt type alloy material, for example.
[0008]
[Means for Solving the Problems]
The present invention relates to a method for joining iron-cobalt alloy materials that form a rollable joint, and uses high energy beam welding methods such as laser welding and electron beam welding that are also used for high-speed joining of steel plates. By applying the cooling rate after welding, the cooling rate is such that the α′CsCl ordered phase does not appear in the welded part and the heat affected zone, and the αBCC disordered phase without the α′CsCl type ordered phase is formed in the joint. Features.
[0009]
Solidification and phase transformation of this 50% Co-Fe alloy with a large saturation magnetic flux density and its phase transformation temperature are:
Liquid phase → r 1480 ° C. r: FCC non-magnetic phase r → α 980 ° C. α: BCC irregular phase α → α ′ 730 ° C. α ′: CsCl type ordered phase.
[0010]
The reason why this Co—Fe-based soft magnetic material has good soft magnetic properties in the vicinity of Co 50% is considered to be due to the α ′ ordered phase existing at 730 ° C. or less, and the permeability deteriorates in the irregular phase. However, the mechanical properties in this α ′ ordered phase are extremely inferior in workability such as cold rolling and punching as in the case of general ordered alloys. Therefore, in this Co—Fe-based alloy, the α ′ ordered phase is not allowed to exist in the joint, and the toughness that can be cold worked on the joint is obtained. Can be used for cold working.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, as in the case of a normal steel plate, even in the case of rolling a Co—Fe-based alloy, it is possible to perform supplementation by welding at an intermediate stage.
[0014]
【Example】
Fe-Co soft magnetic material consisting of 48.93 weight percent cobalt, 1.76 weight percent vanadium, residual iron and inevitable impurities is hot-rolled at a temperature of 730 ° C or higher, and the processing strain is released after the processing is completed. Within a time period that is not performed, a material that suppresses the appearance of an α ′ ordered phase by cooling from a temperature range of 730 ° C. or more to a temperature of 300 ° C. or less at a cooling rate of 100 ° C./s or more is cold-rolled and a width of 85 mm A coil material having a plate thickness of 1.15 mm was obtained. This was cut into a length of 52 mm to obtain a specimen for welding.
[0015]
Two cold-rolled sheets were butted together to form an I-groove perfect butt. When this portion was subjected to electron beam welding under the conditions of an acceleration voltage of 70 kV, a beam current of 10 mA, a welding speed of 500 mm / min, a processing distance of 300 mm, and a beam convergence distance of 260 mm, no regular structure was present at the joint. When this joined plate is continuously cold rolled by repeating it multiple times on a two-stage roll type rolling mill with a roll outer diameter of 200 mmφ at room temperature, it can be rolled without any problems including the joint part, up to a thickness of 0.45 mm. This can then be rolled into an α ′ phase by hydrogen or vacuum annealing at 850 ° C. for 2 to 4 hours, and a cooling rate in the α-phase region of 2 to 3 ° C. / A regular phase was obtained by min , and a soft magnetic material having a thickness of 0.45 mm, a width of 50 mm, and a length of 240 mm could be obtained.
[0016]
Table 1 shows the magnetic properties of this soft magnetic material.
[0017]
[Table 1]

On the other hand, using the same cold-rolled sheet, acceleration voltage 70 kV, beam current 20 mA, welding speed 500 mm / min, processing distance: 300 mm, beam convergence distance: 260 mm, AC deflection: 1.0 mmφ, 500 Hz As a result of electron beam welding, the base material was included in the joint portion to form an α′-phase CsC1-type ordered phase, and subsequent cold rolling was impossible.
[0018]
Further, the same cold-rolled plate was subjected to TIG welding using a 1.6 mmφ tungsten electrode under the conditions of arc current: 40 A, welding speed: 60 mm / min, argon gas flow rate: 8 liters / min. Cracks occurred in the material, and it was impossible to obtain a sound joint.
[0019]
【The invention's effect】
(1) Since there is no fragile ordered phase in the joint, continuous cold rolling of the iron-cobalt soft magnetic material is possible.
[0020]
(2) By applying a high energy beam welding method as a joining means, the melting region is extremely small and quenching is performed, so that a joined portion having no weak regular phase can be obtained.
[0021]
(3) It is possible to manufacture a thin sheet of cold rolled material in a long length, which has a large ripple effect on subsequent processes such as punching, and can reduce the cost and mass production of the final product.

Claims (2)

A method of joining an iron-cobalt alloy material that forms a rollable joint,
By applying the high energy beam welding method, the cooling rate is such that the α′CsCl type ordered phase does not appear in the welded part and heat-affected zone in the cooling process after welding, and the αBCC non-αBCCl type ordered phase does not appear in the joined part. The joining method of the iron-cobalt type alloy material which forms a regular phase. The method of joining iron-cobalt alloy materials according to claim 1, wherein the high energy beam welding method is laser welding or electron beam welding .