JPS6340629B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention rapidly solidifies a molten metal (including alloys) on the surface of a moving cooling substrate to continuously form an amorphous metal (alloy) ribbon or a crystalline metal (alloy). The present invention relates to a method of manufacturing a ribbon. (Prior Art) Various methods have been disclosed for the method of continuously manufacturing a ribbon from molten metal (continuous molten metal quenching method), but all of them involve molten metal having an opening in a predetermined shape. The material is solidified by impact from a nozzle under a predetermined pressure onto a cooling substrate facing the nozzle opening to form a continuous ribbon. Important manufacturing factors at this time are the shape of the nozzle, the relative arrangement of the nozzle and the cooling substrate, the pressure at which molten metal is ejected from the nozzle, and the moving speed of the cooling substrate.
Moreover, in general, as the width of the ribbon increases, each condition tends to become narrower and more severe. A typical method that has been disclosed in the past as a method for manufacturing wide ribbons is, for example, ``Continuous casting method for metal strips and apparatus used therein'' published in Japanese Patent Application Laid-Open No. 53-5352, which provides an overview thereof. A slot nozzle with a rectangular opening is placed opposite a cooling substrate (roll or belt) at an interval of 0.03 to 1 mm, and the cooling substrate is moved at a speed of 100 to 2,000 m/min to inject molten metal from the slot nozzle onto the surface of the cooling substrate. is sent out, brought into thermal contact, and rapidly solidified to produce an amorphous metal ribbon. In principle, this method has no restrictions on width. However, the problem regarding the thickness of the ribbon has not yet been solved. In other words, the thickness limitations of the prior art exist not only for amorphous metal ribbons that require severe cooling conditions, but also for crystalline metal ribbons that are free of restrictions on amorphization. In other words, when attempting to manufacture a thick ribbon using the conventional continuous molten metal quenching method, the principle method used is to move the cooling substrate in the direction of movement of the puddle (hereinafter referred to as a paddle) formed on the cooling substrate. The purpose of this is to increase the length of the cooling board relative to the speed of the cooling board. In actual production, one of the following methods or a combination thereof may be employed. i.e. Increase the width of the nozzle opening. Increase jet pressure. Increase the distance between the nozzle and the cooling board. Reduce the moving speed of the cooling board. These are the four requirements. Therefore, the present inventors attempted to make a thick thin plate using these four methods, but the results were not good. According to the results, there is a limit thickness that depends on the type of alloy and the material of the cooling substrate, and forcibly increasing the thickness beyond that value using the above methods will not only lead to poor shape and property deterioration of the ribbon. It was found that there were no practical benefits, such as mechanical problems. In other words, the molten metal may adhere to the nozzle and solidify, contacting the moving cooling substrate and destroying the nozzle.Also, when the plate thickness is increased, the free surface of the metal ribbon is exposed to the atmosphere for a longer period of time. As a result, shape defects such as severe ripple-like unevenness and hot water wrinkles appeared, and severe oxidation of the surface caused discoloration.
In addition, when such a phenomenon occurs, for example, in the case of an amorphous alloy, crystals are formed in the surface layer even if it is undetectable by X-ray diffraction, resulting in a decrease in ductility and an increase in coercive force. Properties characteristic of equiamorphous alloys were significantly reduced. For example, when defining the thickness at which the holding force begins to increase as the critical thickness at which crystallization begins, the Fe-Si-B system that showed the largest critical thickness used a copper roll for the cooling substrate. There is a report (IEEE Trans.on Mag.18 (1982) P1385) that the thickness of Fe ₇₄ −B ₁₆ −Si ₁₀ is 42 μm in the case of Fe _80.5 Si _6.5
When the width of the B ₁₂ C ₁ alloy ribbon is 25 mm, the critical thickness is
It was 32 μm. Based on these experimental results, the inventors reached the conclusion that the essential measure to produce a thin strip with a thick plate and stable properties is to drastically improve the cooling capacity of the production system. There was no other option. Conventionally, as a method to improve the cooling capacity of manufacturing systems, for example, a method of preventing air entrapment between the cooling board and the paddle (Japanese Patent Laid-Open No. 54-76432
A method of casting in vacuum or He gas (Japanese Unexamined Patent Publication No. 1983-32550), a method of spraying gas on the free surface of the ribbon on the exit side (U.S. Patent No.
A number of methods have been proposed, including the method of pressing an auxiliary roll or belt against the ribbon (Japanese Patent Application Laid-open No. 54-76435), and the method of pressing an auxiliary roll or belt against the ribbon (Japanese Patent Application Laid-open No. 54-23030). However, these methods cannot be used industrially due to reasons such as economic efficiency and mass production, or even if they can be used, the effects are small. In addition, as a method for manufacturing thick amorphous metal ribbon, molten metal is flowed out from multiple nozzles installed at different positions on a cooling roll, and the molten metal flowing out from one nozzle is solidified and then A method of polymerizing a ribbon of molten metal flowing out from the other nozzle is proposed in Japanese Patent Laid-Open No. 126051/1983. However, since this method polymerizes onto the solidified ribbon, the two ribbons are not integrated. Furthermore, Japanese Patent Application Laid-Open No. 18582/1983 describes a method for manufacturing an amorphous metal ribbon with a thickness of 100 μm or more by using multiple nozzle ports and jetting molten metal onto a cooling substrate from each nozzle port. Proposed. This method is effective as a means for producing thick metal ribbons. However, it is difficult to manufacture metal ribbons, especially amorphous metal ribbons, which have excellent shapes and properties and are large in thickness, using only the contents disclosed in this publication. The present invention further advances the technical idea disclosed in Japanese Patent Application Laid-Open No. 55-18582. (Objective of the Invention) The purpose of the present invention is to obtain a large cooling effect that could not be achieved with the conventional technology as described above. Alternatively, it has made possible mass production of crystalline metal (alloy) ribbons. (Structure and operation of the invention) The present invention utilizes a multi-slot nozzle equipped with two or more parallel openings to continuously produce a metal ribbon by spouting and quenching molten metal onto the surface of a moving cooling substrate. Before the ribbon drawn out from the reservoir of molten metal ejected onto the cooling substrate completes solidification, the next reservoir is pressed against the ribbon, thereby thermally bonding the ribbon and the cooling substrate. While increasing the contact, the thin strip drawn from the sump is polymerized onto the first thin strip until a predetermined thickness is obtained.
The method is characterized in that the thin strips formed upstream in sequence are subjected to pressure by adjacent pools to increase thermal contact between the ribbons and the cooling substrate, and the ribbons drawn out from the pools are polymerized and integrated. That is. The gist of the present invention will be explained below with reference to the drawings. FIG. 1 is an explanatory diagram showing an overview of the present invention, FIGS. 2 and 3 are explanatory diagrams of a multi-slot nozzle used in the present invention, and FIG. 4 is an explanatory diagram showing an actual example of the method of the present invention. It is a belt-shaped cooling board that moves in the direction of the arrow in Figure 1.
2 is the crucible, 3 is the nozzle part installed on the bottom of the crucible,
This nozzle part has a plurality of parallel openings 4, 4', .
...is provided. Note that the crucible 2 and the nozzle section 3 may be provided separately. 5, 5'...... is the opening 4,
A sump (hereinafter referred to as paddle) formed by the molten metal 6 flowing out from 4', 7 is the manufactured thin ribbon metal. In order to produce a metal ribbon with a large thickness according to the present invention, a metal (alloy) material is melted in a crucible 2 in the same manner as in a known method, and the opening 4 of the nozzle part 3,
The molten metal 6 flows out onto the cooling substrate 1 moving in the direction of the arrow in FIG. molten metal 6 flowing out from the second opening 4' forms a puddle 5' on the ribbon 7 which has been drawn out from the ribbon 5 and has not yet completed solidification;
The ribbon 7 is pressed to increase the thermal contact between the ribbon 7 and the cooling substrate 1, and the ribbon 7' made from the paddle 5' is polymerized. At this time, since the ribbon 7 has sufficient cooling power as described above, the ribbon 7'
The thin ribbon 7 is also rapidly cooled and integrated with the thin ribbon 7.
(Fig. 4) In this way, on top of the thin strip formed from the puddle immediately upstream and whose surface is in an unsolidified state, the thin strip formed from the puddle of molten metal flowing out from the next opening is polymerized and integrated. As a result, a thick ribbon is formed. The ribbon thus obtained according to the present invention is thicker than that obtained by the conventional method, and has excellent shapeability with no hot water wrinkles or warpage on the surface. Furthermore, despite the large thickness of the plate, there is no crystal formation on free surfaces, and therefore a material with excellent mechanical properties, magnetism, etc. can be obtained. That is, in the present invention, thermal contact with the cooling substrate increases at the beginning of solidification, when the unsolidified portion of the molten metal accounts for a considerable proportion, so the cooling rate in the temperature range most important for properties is significantly improved. As a result, a ribbon can be obtained that is more than twice as thick as the conventional method. In addition, since the paddle is divided and the downstream paddle is formed on the formed thin strip, the time that the free surface of the thin strip is exposed to the atmosphere is approximately equal to the number of openings. The length is inversely proportional, and as a result, the chance of oxidation, crystallization, etc. of the free surface is extremely reduced, and therefore, despite the thick plate, there is no deterioration of characteristics or defective shape. In the present invention, the optimum paddle spacing is determined by the width of each opening measured in the direction of movement, the distance between the opening and the cooling substrate, the jetting pressure of molten metal, the moving speed of the cooling substrate, etc., but usually is about 0.2 to 4 mm. Here, the spacing of the paddles is shown in Figure 4.
Defined by d′. However, the downstream starting point of the paddle is
The height of the paddle is set to be 1/2 of the distance between the upper end of the paddle and the upper surface of the ribbon to be pulled out. In addition, the width direction of the opening of the nozzle for forming the paddle should be parallel to the moving direction of the cooling board, and the surface of the nozzle with the opening should be almost parallel to the surface of the cooling board. do. Although the dimensions and spacing of the openings depend on other factors such as manufacturing conditions, the following ranges are usually appropriate. Opening length (l): Almost the same length as the width of the ribbon Opening width (w): Maximum 0.8 mm, the minimum is the minimum value in principle where the paddles do not overlap, but in reality Lower limit for slitting (approximately 0.2 mm) Distance between openings (d): Determine according to the shape and size of the openings and the desired thickness of the plate. (Usually 0.5 to 4 mm) When the plate thickness is further increased, the width of the openings is decreased, the number thereof is increased, and the distance between the openings is narrowed. In the inventor's experience, there is a range of plate thicknesses that can produce materials with good shapes and properties depending on the number of openings, and in the case of Fe-based + semimetal, the width
15 to 45 μm for one 0.4 mm aperture, 30 to 45 μm for two apertures
60 μm, and 40 to 70 μm in three cases. Therefore, when manufacturing an amorphous metal ribbon, it is possible to manufacture a ribbon with a thickness of 45 μm or more even if it is as wide as 20 mm or more. Therefore, if this method is extended, in principle there should be no limit to the thickness. However, in the case of amorphous materials, there is a thermal conductivity depending on the composition and a critical cooling rate at which the material becomes amorphous, and even in the case of the present invention, there is a limit to the maximum plate thickness, but the upper limit is significantly expanded compared to conventional methods. do. Furthermore, if the purpose is not to make the material amorphous, that is, if it is applied to the manufacture of thin strips such as silicon steel sheets and stainless steel sheets, it is possible to eliminate the limitations in sheet thickness due to oxidation and shape deterioration that were problems with conventional methods. can. (Example) Next, an example of the present invention will be shown. Example 1 A multi-slot nozzle with two openings as shown in Fig. 2 (opening length l: 25 mm, width w:
0.4 mm, distance between openings d: 1 mm), and the composition Fe _80.5 was obtained by a single roll method using a copper roll.
An amorphous alloy ribbon of Si _6.5 B ₁₂ C ₁ (atomic %) was produced. The manufacturing conditions are a distance of 0.15 between the roll surface and the nozzle surface.
mm, ejection pressure 0.22 Kg/cm ² , and roll surface speed 25 m/sec. The thickness of the obtained thin ribbon was 45 μm on average, and no crystallization was observed by X-ray diffraction.
It had magnetic properties equivalent to the 25-30 μm thick amorphous alloy ribbon manufactured in

[Table] Example 2 Multi-slot nozzle with three openings as shown in Fig. 3 (opening length l 25 mm, width w 0.4 mm,
An amorphous alloy ribbon having a composition of Fe _80.5 Si _6.5 B ₁₂ C ₁ (atomic %) was produced by a single roll method using a distance between the openings (d ₁ =d ₂ =1.0 mm). The manufacturing conditions were the same as in Example 1. The thickness of the obtained ribbon is average
Completely amorphous at 60μm, and 25-30μm thick manufactured by conventional method (single nozzle)
The magnetic properties were equivalent to those of the amorphous alloy ribbon. Table 2 shows its characteristics.

[Table] Example 3 Multi-slot nozzle with three openings as shown in Fig. 3 (however, l25mm, w0.4mm, d ₁ = d ₂ = 1.5
mm) and 6.5wt% by iron single roll method.
A thin ribbon of Si steel was manufactured. The manufacturing conditions were: the distance between the roll surface and the nozzle was 0.2 mm, the ejection pressure was 0.22 Kg/cm ² , and the roll surface speed was 22 m/sec. The thickness of the obtained ribbon was 63 μm on average, the average crystal grain size was 10 μm, and the surface quality and shape of the ribbon were very good. Example 4 Using a multi-slot nozzle having the same shape and dimensions as in Example 3, a stainless steel ribbon was produced by a single iron roll method. Manufacturing conditions are as in Example 3.
The same composition as Cr _16.5 (wt%, same below), C _0.06 ,
_Si0.6 , _Mn0.5 , _P0.025 , _S0.005 . The thickness of the obtained ribbon was 58 μm on average, the grain size was 5 μm on average, and the surface quality and shape of the ribbon were very good. (Effects of the Invention) As explained above, the method of the present invention divides the paddle and forms each puddle on the unsolidified ribbon formed immediately upstream, so that the ribbon and the cooling substrate are in thermal contact with each other. Therefore, it is possible to significantly increase the cooling rate of the ribbon, and as a result, a ribbon with a large thickness can be obtained. Moreover, it not only has excellent formability without the occurrence of hot water wrinkles or warping, but also has less chance of surface oxidation because the free surface is exposed to the atmosphere for less time, and is thicker. Despite this, there are excellent effects such as no crystal formation and the ability to obtain a product with uniform properties in the thickness direction.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the method of the present invention, FIGS. 2 and 3 are explanatory diagrams showing a nozzle used in the method of the present invention, and FIG. 4 is an explanatory diagram showing the production of a ribbon by the method of the present invention. DESCRIPTION OF SYMBOLS 1... Cooling board, 2... Crucible, 3... Nozzle part, 4, 4'... Opening part, 5, 5'... Water reservoir part, 6
... Molten metal, 7,7'... Thin strip.

Claims (1)

[Claims] 1. When rapidly cooling molten metal by jetting it onto the surface of a moving cooling substrate to continuously produce a metal ribbon, the distance between the openings of the nozzles is 0.5 to 4 mm in the direction of movement of the cooling substrate. Using a multi-slot nozzle with two or more parallel openings, a strip of molten metal ejected onto a cooled substrate is drawn from a puddle and passes through the next puddle before completing solidification. By pressing against the thin strip, the thermal contact between the thin strip and the cooling substrate is increased, and the thin strip formed by the pool is superposed on the first thin strip until a predetermined thickness is obtained. The method is characterized in that the thin strips that are drawn out from the reservoirs are polymerized and integrated by applying pressure from adjacent reservoirs to the ribbons formed upstream in order to increase the thermal contact between the ribbons and the cooling substrate. A method for manufacturing a thin metal strip. 2. The method for manufacturing a metal ribbon according to claim 1, wherein the spacing between the sump parts is 0.2 to 4 mm. 3. The method for manufacturing a metal ribbon according to claim 1, wherein the manufactured amorphous metal ribbon has a thickness of 45 μm or more and a width of 20 mm or more.