JPS5825433A - Directional property silicon steel band - Google Patents

Abstract

PURPOSE:To obtain a directional silicon steel band for a magnetic core material, etc., which has oriented an axis of easy magnetization in the lengthwise direction, by radiating slit-like radiation heat to a silicon steel band obtained by a super-quenching method, relatively moving this heat treatment part and the steel band, and heating them. CONSTITUTION:To a super-quenching steel band 31, slit-like radiation heat is radiated by adjusting a position of a light source 32 for executing the heat treatment, condensing lenses 33, 35, and a slit 34. In this case, a surface layer of the steel band is melted by a condensing line 36, but the center part is constituted so as to be held in a coagulated state. When this optical system is moved in the direction as indicated with an arrow A or B, a boundary of the condensing line 36 moves at the almost same speed as a moving speed of the optical system, and a movement of a heat current also becomes in parallel with a movement of the optical system. A speed of a relative movement of a heat treatment of this band is sent to about 0.01-10mm./min. As a result, the crystal priority length direction is put in order in the lengthwise direction, and it is possible to obtain a directional silicon steel plate for a magetic core materal, which is excellent and low in its loss.

Description

[Detailed description of the invention] % of oriented silicon steel strip.

Silicon steel sheets are one of the most representative magnetic cores for modern transformers, and in particular grain-oriented silicon steel sheets whose easy magnetization direction coincides with the rolling direction are probably the most excellent as power transformer magnetic cores. However, one of the things that has been researched to further improve this is high-silicon iron alloys. Compared to conventional 3T silicon iron, this alloy has a silicon content of around 6.5, which increases electrical resistivity and reduces magnetostriction and magnetocrystalline anisotropy, leading to lower iron loss and noise as a magnetic core. It is expected as such. Despite having these characteristics, this alloy has not yet appeared as an industrial product because it is brittle and difficult to cold-roll.

On the other hand, it is well known that in recent years, a pyrolytic ribbon production technique called ultra-quenching method has been developed and is applied to the production of ribbons of amorphous alloys and brittle crystalline alloys. From this background, it is also known that it has been applied to high-silicon iron alloys (nearly 65 silicon) and that ribbons with excellent toughness have been obtained. The single roll method shown in FIG. 1 has been developed as one of the liquid ultra-quenching techniques and is most commonly used. That is, as shown in the figure, molten metal 1 is heated and held in a heat-resistant nozzle 2 by an induction coil 3, and the molten metal 1 is injected with gas from a nozzle opening 5 onto the surface of a metal body 4 that is rotating at high speed. The thin ribbon 6 is created by forcibly ejecting the material under pressure and performing ultra-rapid cooling. An analysis of this manufacturing method shows that immediately after the ejected molten metal 1 reaches the roll surface, most of the heat of the molten metal 1 is dissipated on the surface of the metal body 4. At this time, as shown in FIG. 2, the solidified portion 7 originates from the side 8 of the metal body 4 and gradually moves toward the free surface 9. Therefore, since the direction of heat flow occurs in the direction shown by arrow A, the crystal preferential growth direction is also oriented in the direction of arrow A, similar to the direction of heat flow.

Silicon steel has a body-centered cubic crystal structure, and the preferential growth direction of its crystals is (100), so (100) tends to face the direction of heat flow. In other words, it is mainly the axis of easy magnetization (100)
However, the copper strip will be peeled in the thickness direction. When such a copper strip is toroidally wound and used in a magnetic core of a transformer, etc., the magnetization direction and the axis of easy magnetization do not match, so the excitation characteristics and iron loss are not improved much compared to conventional oriented silicon steel sheets. Therefore, in order to improve these properties, it is necessary to orient <ioo> in the longitudinal direction of the ultra-quenched steel strip.

As a result of various studies, the inventors discovered the following. In other words, if an ultra-quenched steel strip is heat-treated in an inert atmosphere, (100) will be very well oriented in the direction of movement of the strip (relative; the same is true even if the strip is fixed and the sample is moved). I understand. However, the conditions for the thermal treatment according to the present invention must be very strictly controlled.

FIG. 3 is a diagram showing the configuration of a band heat treatment section 30 used in the present invention, in which 31 is an ultra-quenched steel strip, 32 is a light source, and 33 is an ultra-quenched steel strip.
34 is a first condensing lens, 34 is a slit, 35 is a second condensing lens, 36 is a condensing line, and 37 is a transparent quartz tube for creating an atmosphere. First, a light source 32 having an output power sufficient to heat-treat the ultra-quenched steel strip 31, a first condenser lens 33 so that the ultra-quenched steel strip 31 is irradiated with light energy in a predetermined state, The positions of the slit 34 and the second condensing lens 35 are adjusted. In other words, if the heat-treated band is too wide, sufficient thermal energy will not be supplied and the copper strip will not be oriented, and if the heat-treated band is made too narrow, the copper strip will completely melt and will not be able to maintain its shape. Therefore, the surface layer of the copper strip is dissolved in the condensing line 36, but
The center must be retained to the extent that it remains solidified.

After adjusting the optical system to give such thermal energy, when the entire optical system is moved in the direction of arrow B or arrow C, an interface between the melting part and the solidifying part is created in the condensing line 36. Therefore, this interface moves at almost the same speed as the moving speed of the optical system, and the movement of heat flow is almost parallel to the movement of this optical system, resulting in crystal preferential growth orientation (5t-Fe system,
(100)) are aligned in the longitudinal direction.

When the ultra-quenched steel strip is subjected to band heat treatment as described above, it becomes possible to orient the <100> in the direction of movement of the steel strip, that is, in the longitudinal direction of the copper strip. The speed of the heat treatment is preferably 0.01 m/min to 10 W/min. Table 1 shows a comparison of the iron loss values of the copper strip obtained according to the present invention and samples obtained in an ultra-quenched state and subjected to conventional heat treatment. It can be seen how superior the copper strip obtained by the present invention is compared to the conventional best oriented silicon steel sheet.

Table 1 Comparison of iron loss between a copper strip subjected to band heat treatment according to the present invention and a conventional steel strip Next, the specific structure of the present invention will be explained based on examples.

Example 1 A silicon steel strip obtained by ultra-quenching with a composition of 67% by weight 5i-Fe was heated in the apparatus shown in FIG.
), and the (001) orientation in the longitudinal direction of the obtained silicon steel strip was simply determined by the ratio of the saturation magnetization (■s) to the residual magnetization (Ir) of the DC magnetization curve < I r
/xs). The results are shown in FIG.

Example 2 An ultra-quenched steel strip having a composition of 6.5% by weight 84-Fe was subjected to heat treatment at V = l 1 m/min using the apparatus shown in Fig. 3, and the obtained silicon steel strip was made into a toroidal magnetic core and wound. 50Hz
The iron loss (W15AO) was measured. Wls, 4o
= 0.7W1kg. However, the measured magnetic flux density is 1.5T.

As described above, in the present invention, by subjecting an ultra-quenched steel strip to band heat treatment, (001) is oriented in the longitudinal direction, and an excellent low-loss magnetic core material can be obtained.

[Brief explanation of the drawing]

Figure 1 is a diagram of the principle of producing ultra-quenched steel strips, and Figure 2 is based on the heat flow during solidification by the ultra-quenching method.
FIG. 3 is a diagram for explaining the direction of axis growth. FIG. 3 is a principle diagram of the band heat treatment section for obtaining an oriented silicon steel strip according to the present invention. FIG. 4 is a diagram showing the degree of orientation depending on the speed of the band heat treatment. FIG. 30... Strip heat treatment section, 31... Ultra-quenched steel strip, 32.
... Light source, 33... First condensing lens, 34... Slit, 35... Second condensing lens, 36... Condensing line, 37... Quartz tube. Figure 1 Figure 2 Figure 3

Claims (2)

[Claims] (1) A silicon-copper strip containing 65% by weight of silicon obtained by an ultra-quenching method is moved relative to the silicon steel strip by a slit-shaped heat-treated band that emits radiant heat. 1. An oriented silicon steel strip characterized in that the silicon steel strip is heated while being heated so that an axis of easy magnetization is oriented in the longitudinal direction of the silicon steel strip. (2) The speed of the relative movement is 0. The oriented silicon steel strip according to claim (1), characterized in that the oriented silicon steel strip has an O1 to 10 m/min.