JPH07214250A - Cooling roll for manufacturing rapidly solidified thin metal strip - Google Patents

Abstract

PURPOSE:To obtain a cooling roll which enables stable manufacturing of a thin strip for a long time by forming a film, which is a metallic oxide layer held and laminated between sprayed metal layers, in a specific thickness on the surface of a roll barrel made of copper or copper allay. CONSTITUTION:A thin strip is obtained by injecting a molten metal from a nozzle to a cooling roll and rapidly solidifying it on the cooling roll. This cooling roll 5 for manufacturing rapidly solidified thin metal strip is made of copper or copper alloy, and provided with a sleeve 7 having a passage 8 for cooling water on the arbor 6. On the surface of this roll barrel, a film is formed desirably in the thickness of 0.3mm or less, which film is made by holding and laminating a metallic oxide layer 11 having the thickness of 0.005-0.05mm between sprayed metal layers 9, 10 having the thickness of o.os and the shell of 0.2mm. The sprayed metal layers 9, 10 and the metallic oxide layer 11 are desirably made of Cu, Mo or their alloys as the basic materials. Consequently, a cooling roll is obtain which is superior in resistance against wear, erosion, and partial embrittlement as well as in the cooling speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quenched metal ribbon (hereinafter simply referred to as a ribbon) directly from a molten metal using a roll whose inside is water-cooled, represented by a twin roll method or a single roll method. The present invention relates to a chill roll used in the process of manufacturing

[0002]

2. Description of the Related Art As a method for directly producing a thin strip from a molten metal (hereinafter referred to as a molten metal), there is known a method in which the molten metal ejected from a nozzle is brought into contact with the surface of a roll body of a cooling roll rotating at high speed to cool and solidify the molten metal. Has been.

This method includes a single roll method using one cooling roll and a twin roll method using two cooling rolls. That is, in the single roll method, as shown in FIG. 1, the molten metal 3 is injected from the nozzle 2 toward the peripheral surface of the cooling roll 1,
The melt 3 contacting the peripheral surface of the cooling roll 1 is rapidly cooled and solidified to produce the ribbon 4. Further, in the twin roll method, as shown in FIG. 2, a pair of cooling rolls 1 are arranged with a slight gap, and a molten metal 3 is injected from a nozzle 2 between both cooling rolls 1,
A thin strip 4 is manufactured by being sandwiched between the cooling rolls 1 and cooled and rolled at the same time.

In any of the methods, an extremely high cooling rate of about 1000 to 100,000 ° C./s is required to produce a ribbon, and therefore a material having high thermal conductivity is used for the cooling roll.

For example, in the left column on page 1 of JP-A-56-30061, surface coating with a heat-removing metal selected from the group consisting of copper, silver, molybdenum and alloys thereof, and improvement of wettability and resistance Chromium surface coating to improve wear resistance
(3) (upper column on page), a cooling body such as a roll or a belt is disclosed.

In order to prevent the roll surface from being damaged, a carbide or nitride surface coating may be applied to the right column on page (2) of JP-A-56-119649 or 56-11965.
They are disclosed in the right column on page (2) of Japanese Patent Publication No. 0, respectively.

Further, in the right column on page (2) of JP-A-55-165261, a metal coating of chrome, iron, nickel or their alloys having good wettability is provided on the roll surface of copper or copper alloy. It is disclosed to apply.

[0008]

However, the coating film formed on the chill roll, especially made of copper, silver, molybdenum, or an alloy thereof, suffers from severe wear and melt damage when the ribbon is manufactured for a long time, resulting in surface texture. It is disadvantageous in that a good ribbon cannot be stably manufactured, and it is expensive as a material for a cooling roll.

Further, chromium used as a film for the roll,
Iron, nickel, carbides, and nitrides all have lower thermal conductivity than copper and molybdenum alloys, and thus the cooling rate required for forming the ribbon cannot be obtained.

Furthermore, for example, when manufacturing a ribbon having a width of 100 mm or more, the surface temperature in the width direction of the cooling roll greatly varies, and partial embrittlement (insufficient cooling rate) occurs in the width direction of the ribbon.

Therefore, the present invention solves the above problems and enables stable ribbon production over a long period of time.
The purpose is to propose a cooling roll.

[0012]

The present invention relates to a cooling roll for quenching and solidifying a molten metal by receiving an injection flow of the molten metal, wherein the surface of a roll cylinder made of copper or copper alloy has a thickness of
0.005-0.05mm thickness between 0.05-0.2mm metal sprayed layers
A chill roll for producing a quenched metal ribbon, which is characterized in that a coating film formed by sandwiching the metal oxide layer of is formed.

Here, the thickness of the coating is preferably 0.3 mm or less. Further, it is advantageous to use a material selected from Cu, Mo and alloys thereof for the metal spray layer and the metal oxide layer.

Next, the cooling roll of the present invention will be specifically described with reference to FIG. As shown in FIG. 1A, the cooling roll 5 is formed by shrink-fitting a sleeve 7 of copper, molybdenum or an alloy thereof on the outer periphery of an arbor 6. The inner peripheral surface of the sleeve 7 is formed with a groove extending on the circumference thereof to form a cooling water passage 8 between the arbor 6 and the sleeve 7 to cool the sleeve 7.

On the other hand, on the surface of the sleeve 7, as shown in an enlarged view in FIG. 1B, a very thin metal oxide layer 11 is provided between the metal sprayed layers 9 and 10 of a plurality of layers, in the illustrated example. And a coating 12 with the interposition of. The coating 12 first forms a metal sprayed layer on the surface of the sleeve 7, then forms a metal oxide layer by oxidizing the surface of the metal sprayed layer, and further forms a metal sprayed layer on the metal oxide layer. Obtained by forming. Here, the provision of a plurality of metal spray layers, when the molten metal is solidified, it becomes difficult for heat to be transferred to the cooling roll due to the metal oxide layer and spread in the roll width direction, so that the amount of heat taken by the cooling roll is reduced. This is because the unevenness in the roll width direction is eliminated, and therefore, the non-steady portion in the initial stage of manufacturing is avoided, whereby the temperature rise of the roll is accelerated and the quality of the ribbon is improved.

[0016]

[Function] In the coating film formed on the surface of the cooling roll, the metal sprayed layer is preferably copper, molybdenum or an alloy thereof having good thermal conductivity, and the thickness thereof is 0.05 to 0.2 mm, more preferably 0.08 to 0.15 mm. To do. That is, if it is less than 0.05 mm, it is difficult to form a sprayed coating with good adhesion on the surface to be sprayed (sleeve base material or metal oxide layer), and the coating surface after spraying cannot be polished, resulting in large surface irregularities. However, air entrapment occurs, and defects such as holes and sagging occur in the ribbon. On the other hand, if it exceeds 0.2 mm, the effects of temperature uniformity in the roll width direction and unsteady avoidance cannot be obtained.

The thickness of the oxide layer is 0.005 to 0.05 mm,
More preferably, it is 0.01 to 0.03 mm. That is, 0.005m
If it is less than m, it is practically impossible. On the other hand, if it exceeds 0.05 mm, the heat removal ability of the roll is lowered, and it becomes difficult to obtain an amorphous ribbon.

Furthermore, the total thickness of the coating is preferably 0.3 mm or less. This is because if the thickness exceeds 0.3 mm, the heat removal capability of the cooling roll is reduced, crystallization of the ribbon occurs, internal stress in the thermal spray layer increases, and peeling due to thermal shock occurs.

As the coating, first, a metal sprayed layer (first layer) formed directly on the roll sleeve is provided, and then a metal oxide layer (second layer) is formed thereon. At this time, the metal sprayed layer of the first layer may be made of the same material as or a material different from that of the roll sleeve. Then, the metal oxide layer is a single layer and the first
The layer is composed of a thermally sprayed layer of oxide. Further, the third and subsequent layers may be a plurality of metal sprayed layers, and it is desirable that the maximum number of layers is four as in the embodiment due to the limitation of the coating thickness.

[0020]

EXAMPLES On the surface of a sleeve made of the material shown in Table 1,
Similarly, using a cooling roll that has been subjected to the surface coating treatment shown in Table 1, using the single roll method, under the following conditions, the plate thickness is 30 μm and the width is 2 μm.
A 00 mm amorphous ribbon was prepared. The surface properties of the ribbon thus obtained and the results of observing the roll surface after the ribbon production are also shown in Table 1.

Manufacturing conditions: Steel type: Fe-13 at% B-9 at% Si-0.3 at% Mn-Cooling roll Roll diameter: 800 mm (outer diameter) Roll width: 500 mm Sleeve base material thickness: 5 mm-Roll peripheral speed: 25m / s ・ Steel tapping temperature: 1325 ℃ ・ Heat size: 1t

[0022]

[Table 1]

As is clear from the table, when the cooling roll according to the present invention is used, the temperature distribution in the roll width direction is uniform, the roll temperature rises quickly, and there are few unsteady portions, so the surface quality is good. An amorphous ribbon was obtained.

[0024]

EFFECTS OF THE INVENTION By using the cooling roll of the present invention, it is possible to stably produce a large amount of uniform wide ribbons which are not embrittled.

[Brief description of drawings]

FIG. 1 is a schematic diagram illustrating production of a ribbon by a single roll method.

FIG. 2 is a schematic diagram illustrating production of a ribbon by the twin roll method.

FIG. 3 is a schematic view showing a cooling roll according to the present invention.

[Simple explanation of symbols]

 1 Cooling Roll 2 Nozzle 3 Molten Metal 4 Thin Strip 5 Cooling Roll 6 Arbor 7 Sleeve 8 Flow Path 9 Metal Spray Layer 10 Metal Oxide Layer 11 Metal Spray Layer 12 Coating

Claims (4)

[Claims] 1. A cooling roll for quenching and solidifying a molten metal by receiving an injection flow of the molten metal, wherein the surface of a roll cylinder made of copper or copper alloy has a thickness of 0.05 to 0.2 mm between metal sprayed layers. A chill roll for producing a quenched metal ribbon, characterized in that a coating film is formed by sandwiching a metal oxide layer having a thickness of 0.005 to 0.05 mm. 2. The thickness of the coating is 0.3 mm or less.
Cooling roll described in. 3. The cooling roll according to claim 1, wherein the metal sprayed layer is made of a material selected from Cu, Mo and alloys thereof. 4. The chill roll according to claim 1, wherein the metal oxide layer is made of a material selected from Cu, Mo and alloys thereof.