JPH0452253A - Rapidly solidified foil or rapidly solidified fine wire - Google Patents

Abstract

PURPOSE:To improve hardness and toughness by rapidly solidifying a molten alloy from the solid-liquid coexisting temp. region and dispersing solid phase components into amoeboid state in a matrix consisting of liquid phase components. CONSTITUTION:This rapidly solidified foil or rapidly solidified fine wire can be formed, e.g. by supplying a molten metal via a nozzle 4 to the position between both rotating rolls 2, 3, that is, by rapidly solidifying a molten alloy from the temp. region where solid phase and liquid phase coexist. This rapidly solidified foil or rapidly solidified fine wire has a dual-phase alloy structure where solid phase components are dispersed into amoeboid state in the matrix consisting of liquid phase components.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a quenched ribbon 5 or a quenched thin wire (quenched thin wire) obtained by supplying a molten alloy between a pair of rolls and rapidly solidifying it. In particular, it relates to a metal structure having a novel metal structure with excellent mechanical properties.

[Conventional technology]

The quenched thin ribbons and quenched fine wires obtained by supplying the molten alloy between twin rolls and rapidly solidifying the alloy have a surface texture of 2.
It has been attracting attention in recent years because it has excellent mechanical properties and can be used, for example, in band saws for cutting semiconductor wafers and dot pins for printers. When manufacturing ribbons used in such band saws, etc., molten alloy, in which necessary alloying elements are added to Fe to form a complete solid solution, is heated, for example, in a water-cooled structure and in line contact with each other. It is supplied between a pair of rolls rotating inward and rapidly solidified at a cooling rate of about 10"K/see. When manufacturing thin wires, the annular shape formed on the outer surface of each roll is used. The molten alloy is supplied into the caliber formed by the groove.

The quenched ribbon etc. obtained by supplying the above-mentioned high-speed steel molten metal between twin rolls etc. and rapidly solidifying it have a supersaturated solid solution structure in which the alloying element components are completely dissolved in the Fe matrix. Hardness compared to hot-rolled strip material,
Both WJ properties have improved.

[Problem that the invention seeks to solve]

By the way, the quenched ribbon obtained by rapidly solidifying the high-speed steel molten metal using twin rolls, etc., has excellent mechanical properties such as hardness and toughness as mentioned above, but the applications of this ribbon etc. can be expanded. Therefore, further improvement of mechanical properties is required.

The present invention was made in response to the above-mentioned demands, and an object of the present invention is to provide a quenched thin ribbon or a quenched fine wire that can significantly improve mechanical properties such as hardness and elegance.

[Means for solving problems]

With a view to further improving the mechanical properties such as toughness and hardness of the above-mentioned quenched ribbon, the inventors of the present invention have continued to conduct intensive research on the metal structure of the quenched ribbon, etc., and have discovered the following points. That is, for example, by rapidly cooling and solidifying a high-speed steel molten metal from a solid-liquid coexistence region, a solid phase component is dispersed in a liquid phase component2.
A phase alloy structure was obtained, and it was discovered that the quenched ribbon with such a metal structure has extremely high hardness (and also has excellent toughness). This invention is based on the idea that the above-mentioned requirements can be met by making a quenched ribbon or the like have such a structure.

Therefore, the invention of item 1 of the present application provides that the solid phase component is dispersed in an amoeba-like manner in a fine matrix composed of the liquid phase component obtained by rapidly cooling and solidifying the molten alloy from the solid-liquid coexistence region where the solid phase and liquid phase coexist. This is a quenched thin ribbon or a quenched fine wire characterized by having a two-phase alloy Mi weave.

Here, in the molten alloy in which a solid phase and a liquid phase coexist in the present invention, for example, as shown in the characteristic diagram of the molten alloy temperature and the amount of carbon added in FIG. It can be obtained by setting the temperature lower and higher than the solidus line. It is also possible to precipitate additional element components by cooling a completely melted molten alloy while stirring it.

In addition, the cooling rate when rapidly cooling the above molten alloy is 10'~
It is preferable to set the cooling rate to about 10' K/sec. If the cooling rate is slower than I O' K/sec, the structure becomes brittle without forming the rapidly solidified structure that is the object of the present application, and the thin strip or wire itself becomes brittle. The upper limit of the cooling rate that cannot be obtained is not a restriction due to quality, but the maximum cooling rate that can be obtained at present is about 107/sec.

As a method for achieving the above-mentioned cooling rate, for example, a method of supplying the above-mentioned molten alloy to a cooling body such as twin rolls or a cooling belt of a cooling structure can be adopted.

In addition, when producing a rapidly quenched fine wire, the molten alloy is supplied into a caliber formed by groove-shaped grooves formed on the outer surfaces of a pair of rolls, for example.

In addition, in the present invention, as an organization of MfAI, JP-A-61-1
There is No. 93745. Similar to the present invention, the molten alloy maintained in a solid-liquid coexistence state is supplied to a cooling body such as a rotating roll, and is rapidly solidified at a cooling rate of 10°C/sec or more. The aim is to obtain different complexes of AllIm.

The technical idea of the invention described in the above publication is that when the size of the solid particles dispersed in the liquid phase of the molten alloy is sufficiently large compared to the dendrite arm spacing, the solid particles concentrate at the center of the slab. We are using.

Therefore, it is desired or possible to obtain a ribbon in which the composition of the "surface layer part and the central part" of the cast slab differs by this invention.

In contrast, the structure of the present invention is a two-dimensional structure in which solid phase components are dispersed in an amoeba-like manner in a fine matrix consisting of liquid phase components.
This is a phase alloy structure, which is different from the structure described in the above-mentioned publication, which is a two-layer structure consisting of a surface layer portion and a central portion.

In addition, the invention of item 2 of the present application is characterized in that the molten alloy contains additional elements in an amount exceeding the solid solubility limit. The target is tool steel, such as high speed steel, which cannot be melted using the above method, and which contains additive elements exceeding the solid solubility limit and is manufactured as a powder using the atomization method.

In the invention of item 2 of the present application, it is added in an amount exceeding the solid solubility limit,
While being maintained in a temperature range of solid-liquid coexistence state, the added element existing as a solid phase is continuously heated preferably at 10' K.
By being rapidly solidified at a cooling rate of /sec or more,
As in JP-A No. 61-193745, the structure is not separated into two layers, the surface layer and the center layer, but is unique in that the solid phase component is dispersed in a fine matrix consisting of the liquid phase component in an amoeba-like manner. It becomes a two-phase structure.

The organization of the present invention and the organization of the prior art will be described later with reference to FIGS. 3, 7, and 4 of the embodiments, respectively.

[Effect]

According to the quenched thin ribbon and quenched thin wire according to the present invention, the molten alloy is rapidly solidified from the solid-liquid coexistence region, so that the resulting metal structure has a solid phase in a fine matrix composed of liquid phase components. It has a solid-liquid coexistence alloy structure in which components are dispersed in an amoeba-like manner. For example, if such a structure is obtained from molten high-speed steel, both hardness and toughness can be significantly improved, and the mechanical properties mentioned above can be improved. can meet the requests of

In addition, in the case of tool steel, it is usually rapidly cooled from the austenite sI region to form a two-phase structure of tempered martensite and retained austenite, but in order to improve the strength and hardness of this structure, heat treatment has traditionally been applied. The process was repeated many times to transform the structure into a tempered martensite single phase structure. On the other hand, in the case of the invention structure described in item 2, after the above-mentioned rapid cooling, it becomes a tempered martensitic structure by approximately one heat treatment, and the heat treatment is very easy.

〔Example〕

The present invention will be explained in detail below.

First, a method for manufacturing a quenched ribbon for a band saw having a solid-liquid coexisting alloy structure will be described. In this production method, a quenched ribbon was produced by ultra-quenching a molten high-speed steel alloy from a solid-liquid coexistence temperature range.

First, the twin roll device employed in this manufacturing method will be explained. As shown in FIG. 2, this twin roll device consists of two pressure rolls each having a water-cooled structure. The fixed rolls 3 are supported with their axes facing horizontally, and are configured to be rotated inwardly from each other. Further, the fixed roll 3 is fixed to the housing so as not to move in the direction perpendicular to the axis, and the pressure roll 2 is pressed by a hydraulic cylinder so that the line contact pressure with the fixed roll 3 becomes a predetermined pressure.

Furthermore, a molten metal nozzle 4 is disposed above both rolls 2.3, and a heating device 5 is disposed on the outer periphery of the nozzle 4.

When producing a quenched ribbon using the above twin roll device, the alloy material charged into the nozzle 4 is melted and maintained at a predetermined temperature by the heating device 5, and the molten alloy is passed through the nozzle 4 by both rotating rolls 2.3. It is manufactured by supplying it during the period of time and rapidly solidifying it.

High-speed steel alloys having the compositions shown in columns 1 and 2 of Table 1 were adopted, and the compositions shown in columns 1 and 2 of Table 2 were respectively mixed. 2nd column, 3rd column. A rapidly solidified ribbon was produced by ultra-rapid solidification under the manufacturing conditions shown in column 4.

As shown in the first column of Table 1, KHA30 contains C:I, 3%, and Si: 0.29 as additive elements to Fe.
%, Mn: 0.26%, P: 0.028%,
S: o, ot4%.

Cr: 3.98%, Cu: 0.07%, Ni
:0.15% Mo:4.96%, w':s, 9 layer%,
V22.93% (,047°98% is added), and 6.3fiφ is made from this high speed steel alloy by powder metallurgy method.
×4(2)l9 A sample weighing approximately 10 g was prepared.

The manufacturing conditions for the quenched ribbon using the above KHA30 are shown in Table 2. As shown in the second column, a high-purity liquid nozzle (inner ao, 8 mφ, 1.0 tar φ) was adopted, the charging weight was about 20 g, 40 g, and the discharge pressure inside the nozzle was 0.8 kg/ci, 1.0 kg/cd
of argon gas was injected. In addition, the roll is made of 5UJ-2 with a roll diameter of 79.2 mφ, the rotation speed is 1100 Orp, and the roll reduction blade is 50
kg/3100 kg/cs, and the number of rolls was one.

Further, the cooling rate in this case was set to 10' to 10'Usec.

In the method of this embodiment, the temperature at the start of cooling was set at 1380°C and 1400°C, which was lower than the liquidus temperature of KHA30, 1427°C, and higher than the solidus temperature, 1236°C. As a result, in the method of this embodiment, the molten alloy is ultra-quenched and solidified from a temperature range in which solid and liquid phases coexist to obtain a rapidly solidified ribbon with a width of 4.1 to 4 degrees x 91 to 120 μm in thickness. Ta.

For comparison, KHA60 shown in the second column of Table 1
3 of Table 2 using A comparative ribbon was produced under the manufacturing conditions shown in No. 4W. This KHA60 has Fe and C: 2.
28%, Si: 0.33%, Mn: 0°25%
, P: 0.028%, S: 0.021
%, Cr: 4.06%, Cu: 0.07%, Ni
: 0.16%, Mo: 6.86% W: 6.88
%, V: 6.60%, Co: 10.12%, and from this high-speed steel alloy, 9.0 mm diameter x 4 cmj! is made by powder metallurgy. , jlj amount of approximately 20 g was prepared. The manufacturing conditions are a discharge pressure of 1.2 k
g/cd, 1.0 pupil/-, nozzle diameter 1.2 Tsuruφ, 1
．． 0 Tsuruφ roll diameter 79.2■φ, roll rotation speed 70Or
pm, 900 rp, seaweed roll pressure 100 kg/
cs, roll surface number 3 times 1 time, and cooling rate 10'
~10'/see, 10'~10'/se
c. In this case, the temperature at the start of cooling is set to K
1460℃, higher than the liquidus temperature of HA60, 1316℃
, 1480° C. to rapidly solidify from the complete liquid phase region. In this way, the board width is 15゜1~18.2m,
1.6~1.7 m x plate thickness 111~138, US,
A quenched ribbon of 70 to 103 μm was obtained.

FIG. 3 is a micrograph (X400x) showing the metal structure of the quenched ribbon produced by the method of the above-mentioned Example, and FIG. 4 is a micrograph (X4
00 times).

As is clear from FIG. 4, in the comparative example ribbon that was rapidly solidified from a temperature range higher than the liquidus temperature, a two-layer structure separated into two layers, a surface layer portion and a center portion, was obtained. On the other hand, in the quenched ribbon of the present invention, as is clear from FIG. 3, the solid phase component is dispersed in the liquid phase component as the base in an amoeboid shape, and it is clear that a diwa alloy &lI weave is obtained. I can see that it is being done.

Moreover, the third column of Table 1 shows the results of measuring the composition of the amoeboid part of the above KHA30.

As is clear from the same type, the amoeboid part of the metal structure of the present invention is made of Cr, V, and Co compared to the matrix part.
increases, and Mo and W decrease.

Next, the results of measuring the hardness of the two-phase alloy structure of KHA30 will be explained. FIG. 5 is a microscopic photograph of the object to be measured, and FIG. 6 is a diagram corresponding to a microscopic photograph for specifying measurement points.

E is a measurement point on the matrix as a liquid phase component part, and B, D, and F are measurement points on the precipitate as a solid phase component part. The Pinkers hardness (Hv = 25 gf) at each measurement point was measured, and the average value of the measured values at each point was calculated.

Table 3 shows the results.As is clear from the table,
The hardness of the liquid phase component is 748 at point A, 715 at point C, and 551 at point E. On the other hand, the hardness of the solid phase component is 947 at point B and 1014 at point D. It can be seen that the F point is 870, which is a very high value. By the way, these hardnesses are
This value is approximately 10% higher than that of the quenched ribbon produced by the comparative example method.

In this way, according to this example, the high-speed steel molten metal was ultra-quenched and solidified all at once from a temperature range where the solid phase and liquid phase coexist, so the quenched ribbon obtained by this process had a very large amount of liquid phase components. It has a two-phase alloy structure in which solid phase components with high hardness are dispersed, resulting in high hardness.

Toughness can also be significantly improved. Therefore, when the quenched ribbon of this embodiment is used as a band saw, or the quenched thin wire is used as a dot pin for printing, etc., the service life can be greatly extended and the quality reliability can be improved.

〔Effect of the invention〕

As described above, according to the quenched thin ribbon and quenched thin wire according to the present invention, since the molten alloy is rapidly solidified from the solid-liquid coexistence temperature range,
As a result, a metal structure in which the solid phase component is dispersed in an amoeba-like manner in the liquid phase component is obtained, and as a result, a quenched ribbon or fine wire with excellent mechanical properties can be obtained.

(Hv=25gf)

[Brief explanation of drawings]

Fig. 1 is a phase diagram for explaining the solid-liquid coexistence temperature range of the present invention, Fig. 2 is a schematic configuration diagram showing a twin roll apparatus for producing a quenched thin ribbon, and Fig. 3 is a quenched thin ribbon according to the method of this embodiment. A microscopic photograph showing the metallographic structure of the strip; FIG. 4 is a microscopic photograph showing the metal & II weave of the quenched ribbon according to the method of the comparative example; and FIG. 5 is a microscopic photograph showing the hardness measurement test of the quenched ribbon of this example. FIG. 6 is a schematic diagram corresponding to FIG. 5.

Claims (2)

[Claims] (1) Rapid cooling characterized by having a two-phase alloy structure in which an amoeba-like solid phase component is dispersed in a liquid phase component obtained by rapidly cooling and solidifying a molten alloy from a temperature range where a solid phase and a liquid phase coexist. Thin strip or quenched thin wire. (2) The quenched ribbon or fine wire according to claim 1, wherein the molten alloy contains an additive element in an amount exceeding the solid solubility limit.