JPH07166239A - Production of wire rod of fe-co-v alloy - Google Patents

Abstract

PURPOSE:To produce a long sized wire rod having good magnetic properties by subjecting an Fe-Co-V alloy having a specified componental compsn. to hot rolling, hardening, welding by pressing and cold drawing in succession under specified conditions. CONSTITUTION:An alloy contg., by weight, 47 to 53% Co and 1 to 3% V, and the balance substantial Fe is melted and subjected to hot rolling to form a wire rod of phi6 to 9mm. This wire rod is heated to 850 to 900 deg.C, is hardened in water at <=5 deg.C, is thereafter subjected to welding by pressing at 750 to 850 deg.C in an inert gas atmosphere is then subjected to cold drawing at >=20% reduction of area and is subjected to magnetic annealing. Thus, the long size wire rod having good magnetic properties both in the weld zone and nonweld zone is produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to the production of Fe-Co-V alloy (hereinafter referred to as "permendur") wire rods by crimp welding to elongate them and then subjecting them to cold drawing to obtain good magnetic properties. The present invention relates to a manufacturing method capable of obtaining characteristics.

[0002]

2. Description of the Related Art In recent years, the unit weight of raw materials has been increased for the purpose of cost reduction. However, since permendur generally requires quenching treatment, it was difficult to make it long. As a method of increasing the length, a method of inserting a dissimilar metal into the joint portion, welding it, processing it into a predetermined dimension and shape, and then removing the welded portion by cutting and removing is also being studied.

[0003]

In this method, even if the unit weight of the material is increased, dissimilar metals must be cut and removed in the final step, and a device for detecting the welded portion is required. There was a drawback that the number of manufacturing steps was large. or,
Welding of similar metals has also been carried out, but there was a problem such as characteristic deterioration due to structural change due to the influence of heat. Therefore, the technical problem of the present invention is to improve productivity by crimping and welding permendur wire rods without using dissimilar metals, and specifically, to improve productivity. Another object of the present invention is to propose a manufacturing method in which the welded portion can obtain magnetic characteristics comparable to those of the non-welded portion without deterioration of the characteristics due to the influence of.

[0004]

[Means for Solving the Problem] The wire rod after hot working of permendur is heated to 850 ° C to 9 ° C.
After heating at 00 ° C for 1 to 2 hours, quenching is performed in water at 5 ° C or less, and pressure welding is performed at 750 ° C to 850 ° C in an inert gas atmosphere such as argon gas or nitrogen gas.
% Cold-drawing and magnetic annealing, before cold-welding, perform cold-drawing with a surface reduction rate of 20% or more, then perform cold-drawing by cold-welding, crimp stress Is 130 kg / mm ² or more and less than 170 kg / mm ² , it is possible to supply a wire rod of permendur having good magnetic characteristics in which the welded portion is no different from the non-welded portion.

[0005]

According to the present invention, permendur wire rods are welded and connected without using dissimilar metals, and the welded portion has a uniform structure by cold working with a surface reduction rate of 20% or more before welding.
Further, by performing cold drawing with a surface reduction rate of 20% or more after welding, it is possible to obtain good magnetic properties in which the welded portion is no different from the non-welded portion after magnetic annealing. That is, the unit weight of the material can be increased by welding without using dissimilar metals, and good magnetic characteristics can be ensured even in the welded portion, so that productivity can be improved by lengthening.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 is a diagram showing a schematic manufacturing process of a permendur wire rod by a conventional manufacturing method.
The ingot melted in the vacuum melting furnace is heated to 1000 ° C
After heating to 1100 ° C, it is hot-worked into a billet with a diameter of about 90 mm and surface scratches are removed with a lathe.
After being heated to 1100 ° C, the material hot-rolled to about φ6 to φ9 mm is heated at 850 ° C to 900 ° C, then quenched in cold water at 10 ° C, and then used as a dummy material to increase the unit weight of the material. A stainless steel rod, a mild steel, etc. having the same diameter as the material diameter was pressure-welded, cold drawn to a predetermined size, and then the dummy material was detected and cut and removed.

FIG. 1 is a diagram showing a schematic manufacturing process of a permendur wire according to the present invention. The steps before the dotted line are the same as the conventional method. By subjecting the material processed by the conventional method to cold drawing with a surface reduction rate of 20% or more, the α phase obtained by cold water quenching has a more evenly distributed crystal structure, and this permendur Wet-cut the edges with a fine cutter so as not to be adversely affected by heat, and then surface the edges to increase the contact area during pressure bonding. These two exposed materials are rapidly heated to 750 ° C to 850 ° C, which is a solutionizing temperature or lower, in an inert gas atmosphere such as argon gas or nitrogen gas, and then 130 kg / mm ²
Welding is performed by the pressure bonding stress of 170 kg / mm ^{2 or} less. Table 1 shows the relationship between pressure bonding stress and pullability.
If it is less than 130 Kg / mm ² , fracture occurs in the welded portion during the drawing process, and if it is 170 Kg / mm ² or more, the pressure bonding stress is too large to weld.

[0008]

[Table 1]

After the crimp welding, the buildup of the welded portion due to the crimping is removed by a grinder or the like, and cold drawing with a surface reduction rate of 20% or more is performed.

FIG. 2 is a diagram showing a change in magnetic flux density with respect to the processing rate (area reduction rate) when the area reduction rate of 0 to 40% is processed and then heat treatment is performed at 830 ° C. is there. As can be seen from this figure, in cold working with an area reduction rate of less than 20%, distortion due to thermal effects during welding remains, and good magnetic properties cannot be obtained even with magnetic annealing. By performing the above-mentioned cold drawing, distortion due to heat can be completely removed, and good magnetic characteristics can be obtained after magnetic annealing.

Table 2 shows the quantitative surface analysis results of the permendur welded portion and the non-welded portion which were cold drawn with a surface reduction rate of 20% after welding.

[0012]

[Table 2]

From Table 2, in the welded portion and the non-welded portion, almost no change in the components of Fe, Co and V, which are the main components of permendur, is recognized.

FIG. 3 shows the results of line analysis of Co and V for the same sample as in Table 2 in the case of scanning across the welded portion and the non-welded portions on both sides of the welded portion. The vertical axis is C
The contents of o and V are shown by relative strength. Figure 3
Also, in Co., almost no change in Co and V components was observed.

[0015]

As described above, the use of the permendur wire rod manufacturing method according to the present invention makes it possible to lengthen the wire rod by crimp welding without using dissimilar metals as dummy materials when welding the wire rod. , Then 20% reduction
By performing the cold drawing process described above, it is possible to provide a permendur wire rod manufacturing method capable of obtaining good magnetic characteristics without any change in both the welded portion and the non-welded portion.

[Brief description of drawings]

FIG. 1 is a schematic manufacturing process diagram of a permendur wire according to an embodiment of the present invention.

FIG. 2 is a diagram showing a relationship between a surface reduction rate in cold working and magnetic characteristics according to an example of the present invention.

FIG. 3 is a view showing an example of the present invention in which Co and V are spread over a welded portion and a non-welded portion after cold drawing with a surface reduction rate of 20%.
FIG. 6 is a diagram showing the composition distribution in the direction of the line.

FIG. 4 is a schematic manufacturing process diagram of a permendur wire rod by a conventional manufacturing method.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C22F 1/10 J

Claims (3)

[Claims] 1. A method for producing a wire rod of an alloy having 47 to 53% by weight of Co, 1 to 3% by weight of V, and the balance being substantially Fe, wherein φ6 to φ9 mm hot-rolled after melting.
The wire rod of No. 1 is heated at 850 ° C to 900 ° C, quenched in water at 5 ° C or less, and then 750 ° C to 8 ° C in an inert gas atmosphere.
A method for producing a wire rod of an Fe-Co-V alloy, which comprises performing pressure welding at 50 ° C and then performing cold drawing with a surface reduction rate of 20% or more. 2. The manufacturing method according to claim 1, wherein 85
After heating at 0 ° C to 900 ° C and quenching in water at 5 ° C or less,
A method for producing a wire rod of an Fe-Co-V alloy, which comprises performing cold drawing with a surface reduction rate of 20% or more before pressure welding. 3. The manufacturing method according to claim 1, wherein the crimping stress at the time of crimping welding is 130 kg / mm ² or more 170
Fe-Co- characterized by being less than Kg / mm ² .
V alloy wire manufacturing method.