JPH0353007A - Manufacture of metal strip - Google Patents

Abstract

PURPOSE:To stably manufacture a high quality metal strip by depositing molten metal flow on a reciprocating substrate with gas jet or rotary roll as metal particles and executing hot-rolling or cold-rolling to the obtd. coil. CONSTITUTION:The molten metal 2 charged into a tundish 1 is caused to flow down from a nozzle 3. This molten metal column 4 is atomized through the rotary roll 5. The metal particle flow formed with this, is deposited on the rotary substrate 6 reciprocating in the axial direction. Deposits developed with this are wound into a mandrel 7 synchronously reciprocated with the substrate 6 to form a deposit coil 8. Successively, this coil 8 is passed a rolling mill 10 through a pay-off reel 9 and the hot rolling is executed as it is while utilizing temp. of the material or after cooling, the cold rolling is executed. By this method, the metal strip having good quality and uniform thickness can be stably obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] The present invention relates to a method for producing a thin metal plate, and provides a method that can stably produce a thin metal plate from molten metal and obtain a plate material of excellent quality. This is what we are trying to provide.

(Industrial application field) A technique for producing thin sheets from molten metal.

(Prior Art) The strip caster method, in which molten metal is injected between a pair of rotating rolls, is generally known as a method for directly manufacturing thin plates from molten metal. At present, it has not been put into practical use for reasons such as the outflow of molten metal and the difficulty of controlling molten steel solidification on rotating rolls.

An effective method for solving this problem is, for example, Japanese Patent Publication No. 46-43688, in which, as shown in FIG. Tonashi,
A deposit 25 is formed.

Further, Japanese Patent Publication No. 12220/1983 discloses a method for producing metal articles from metal droplets.

Furthermore, Japanese Patent Publication No. 59-266 discloses a method of controlling the thickness distribution of the deposit 25 in the width direction by using a scanning atomizer 26 and spraying the metal stream 2L from the width direction, as shown in FIG. has been announced.

In addition, there is also a method of arranging atomizers in parallel, for example A.
It has been published in literature such as GARD, m256°76.

Furthermore, Japanese Patent Application Laid-Open No. 47-3805 discloses a method of atomizing the molten metal by once receiving it with a roll and making it into a parallel flow.
A method is shown in which the flow of molten metal in the form of a curtain 27 is atomized with a roll as shown.

(Problems to be Solved by the Invention) Since the method disclosed in Japanese Patent Publication No. 46-43688 described above has a certain distribution of atomized flow of the molten metal,
As shown in FIG. 3, it is not possible to deposit this material to have a uniform thickness in the direction of the temporary cross section.

Even with the method disclosed in Japanese Patent Publication No. 56-12220, it is not possible to obtain a metal molded product that is long in size and has a relatively thin cross section.

The method disclosed in Japanese Patent Publication No. 56-266 has difficulty in controlling the flow of the molten metal, ie, the angle and pressure at which the gas is blown, and the width over which a uniform thickness can be achieved is small, so it has not yet been put to practical use.

In the method of arranging atomizers in parallel, it is necessary to arrange a large number of atomizers in order to obtain a material with uniform thickness and wide width, and there are many unresolved physical problems such as the spacing between them.

Various other ideas have been proposed, such as making the atomizer shake periodically, but none of them have been realized.

The method disclosed in Japanese Patent Application Laid-Open No. 47-3805 inherits the problems of the conventional strip caster method, that is, problems remain in sealing the side of the roll and controlling the solidified shell on the roll. Even in the method shown in Fig. 5, it is impossible to maintain a curtain-like molten metal flow due to the surface tension of the molten metal. In this case, the falling distance and shrinkage width are as shown in FIG. 6, and it is unavoidable that the thickness of the plate end becomes large.

"Principles of the Invention" (Means for Solving the Problems) The present invention was developed after consideration to solve the problems of the conventional products as described above. A metal particle stream is formed by blowing a gaseous diesothoto stream onto the substrate, or a rotating roll is used to form a metal particle stream, and the metal particle stream is deposited on a substrate reciprocating in the axial direction to form a coil, and the coil is moved in the axial direction. This is a method for manufacturing a thin metal sheet, which is characterized in that the metal sheet is paid off from a rotating substrate that reciprocates and is directly hot rolled using the temperature of the material, or cold rolled after cooling.

To explain the present invention as described above with reference to FIG. 1, molten metal 2 accommodated in a tandy sosh 1 is made to flow down from a nozzle 3 to form a molten metal column 4, and this molten metal column 4 is rotated at a rotation speed controlled by the molten metal flow rate. It is made to flow down between rolls 5 and 5 and atomized. After passing through the rotating rolls 5, 5, this molten metal falls onto a rotating nub straight 6 that reciprocates in the axial direction. Instead of the rotating roll 5, it is also possible to atomize with gas. For the rotating substrate 6, if necessary, the substrate 6 can be heated by cooling or heating.
The temperature of the surface is controlled, and the rotating substrate 6 is linked to its rotational speed to determine its axial movement speed and moving distance, and the generated deposit l2 is axially moved in synchronization with the rotating substrate 6. It is wound around a mandrel 7 that reciprocates to form a coil 8. Control of the plate thickness is determined by the flow rate of molten metal and the rotation speed of the rotating substrate 6. This deposited coil 8 usually has a density of 95% or more, but in order to achieve true density or improve mechanical properties,
Generally, hot rolling is performed using the temperature of the coil 8 as it is. For rolling, deposit coil is rolled using rolling machine I.
The rolling mill payoff reel 9 may be either inside or outside the deposit coil making chamber. Of course, materials with good cold workability can be cooled and cold-rolled as they are to produce a final product. In any case, rolling mill 1
0 and then wound onto the take-up reel l1.

When producing high-purity materials, atomization is carried out in particular using rotating rolls and in a vacuum atmosphere. It is also possible to carry out in an inert atmosphere.

As mentioned above, according to the method of the present invention, relatively wide materials can be easily formed, and the resulting materials are such that the atomized particles are rapidly cooled by convection with the gas or contact with the substrate. It produces fine particles without polarization.

To describe each technical element in this process in more detail, the tundish 1 holds the molten metal 2;
In order to keep the thickness of the deposit 12 constant, the liquid level of the molten metal 2 needs to be kept constant. For the tundish nozzle 3, if a high production volume is required, for example, a parallel multi-nozzle, a slit nozzle, etc. can be adopted.

Regarding the atomizing gas, inert gases such as NZ and Ar are mainly used, but the gas pressure and gas flow rate are 2 to 15 kg/cj, and the metal to gas flow rate ratio is 1.
Approximately 00:1 to 1:1 is appropriate.

It is also possible to mix an oxide-generating gas such as oxygen to produce an oxide-dispersed composite material.

Regarding the rotating roll 5, its material and surface roughness determine the particle size to be atomized. That is, the material of the roll and other factors vary depending on the type of molten metal, but qualitatively it can be said as follows.

Material: 1. Must have good wettability with molten metal (stable atomization is possible) Surface roughness: 1. Appropriate roughness (Ra of 50 μm or more) is required.

Regarding the rotating substrate 6, its material and surface roughness greatly affect the shape of the deposit, so the details are as follows.

Material - 1 ------- 1.1 Material that has good wettability with molten metal.

Surface roughness - Appropriate roughness (about Ra 200 μm) is preferable.

Further, at the initial stage of atomization, it is appropriate to place a leader strip on the rotating substrate 6 and the mandrel 7, and to draw out subsequent deposits using the deposit 12 attached to the leader strip. It is desirable to control the temperature of the surface of the rotating substrate 6 in order to maintain constant conditions for deposit attachment.

The speed and distance of axial movement of the rotating substrate 6 and mandrel 7 are very important and, if not properly determined, will result in unsatisfactory stripping. As shown in FIG. 2, when the speed of the rotating substrate 6 is V', the axial movement speed Va, the width Ws, and the width Wd of deposit, the following relationship needs to be satisfied.

2 W s ・(V r / Va ) ≦ Wd However, in order to reduce the axial movement speed at the plate end, increase the plate thickness at the plate end, and prevent edge cracking, the rotating substrate 6 and the mandrel By controlling the movement of 7, actively depot. It is also possible to control the profile.

The temperature of the debossed coil is determined by the size of the coil being created. It is also possible to actively control the temperature by installing a heater inside the coil box. Regarding the rolling mill 10, normally a material with true density can be produced with a reduction of about 10%, but in consideration of improving the mechanical properties of the material, more aggressive reduction is effective.

The present invention is useful not only for producing metal thin plates but also for producing clad plate materials and composite material plates.

In addition, the metal (thin plate) that can be applied is typically iron-based, but it is not limited to iron-based, but can also be applied to non-ferrous metals such as AI-based and Cu-based.
It is effective to keep the melting temperature of the metal in the tundish just above the melting point as much as possible in order to obtain a material with fine crystal grains, but in consideration of nozzle clogging, etc.
It is appropriate to set the temperature to about 0°C, preferably within the range of melting point to melting point +200°C, depending on the operating conditions.

(Example) Specific examples of the present invention will be described below.

Example 1. In the apparatus shown in FIG. 1, the tundish 1
3. Contain 6.5% siff @ of 1550°C in the chamber;
O tmφ×3 tandy sosh nozzle 3 80mm
A pair of 3QQmm x 0.03m strip gas nozzles were installed at intervals, and N2 gas was sprayed at a pressure of 4kgf/cal. Cast iron with a surface roughness R of 100μm was used as the rotating substrate 6, and a 30N /sec and the axial movement speed is 500.
am/sec, and the thickness of the plate made of mild steel is 0. 2 3
Surface roughness R in mm. = 30 μm leader strip was used.

The deposit coil 8 has a temperature of 1000°C and a plate thickness of 5.
．． O u+, unit weight of board width 1000xm 200
kgf, and this is rolled into a rolling mill 10% by 70%.
Rolling was carried out at a rolling reduction ratio of 1.5n to obtain a plate material with a thickness of 1.5n.

This material was then cold rolled into a coil with a thickness of 0.3 mm. In other words, it has been confirmed that the present invention can easily produce even difficult-to-process materials such as those described above.

Example 2. -t%, Cr: 28%, W: 4%, C:l, Q%, F
A 1550°C molten metal made of a stellite alloy with e: 3% or less, Ni: 3% or less, and the balance Co is placed in a tundish l.
The experiment was carried out using the same tundish nozzle and strit gas nozzle as in Example 1.

The rotating substrate 6 has a surface roughness R. =100μ
The rotational speed and axial movement speed were the same as in Example 1, and the league strip was the same as in Example 1.

The obtained deposit coil 8 is similar to Example 1,
The plate was rolled with a rolling reduction rate of 50% using the rolling mill 10 to obtain a plate thickness of 2.5f.
1 of stellite alloy plates were obtained.

The mechanical properties of the product obtained in this way are as shown in Table 1 below when compared with that of the same alloy obtained by the ordinary casting method.According to the present invention, the mechanical properties of It has been confirmed that it is possible to manufacture an alloy plate of 100% by weight, and to appropriately improve its mechanical properties using rapid solidification.

Table 1 Example 3. A 1500° C. hot water made of SUS304 was placed in a tundish 1, the same tundish nozzles and strisoto gas nozzles as in Example 1 were used, and N2 gas was used.

Surface roughness R2 = 100μ for rotating substrate 6
The rotational speed and axial movement speed were the same as in Example 1, and the leader strip was also the same as in Example 1.

The obtained deposit coil 8 is similar to Example ①,
The plate was rolled with a rolling reduction rate of 70% using the rolling mill 10, resulting in a plate thickness of 1.5u.
A SUS 304 alloy plate was obtained.

The mechanical properties of the product thus obtained are shown in Table 2 below when compared with the same SOS304 alloy obtained by the normal casting method. It is clear that it is possible to produce the desired alloy plate and also to obtain a nitrogen-strengthened alloy in this way, whose mechanical properties can be suitably improved.

Table 2 Example 4 A molten metal made of SUS304 alloy at 1500°C was placed in the tundish nozzle 1, the same tundish nozzles and strisoto gas nozzles as in Example 1 were used, and Ar gas was used. did.

The material, rotational speed, and axial movement speed of the rotating substrate 6 were the same as in Example 3, and the same ligustrisop as in Example 3 was used.

The obtained deposit coil 8 is similar to Example 3,
The rolling mill 10 is used to reduce the plate thickness to 1.5 with a rolling reduction rate of 70%.
+n alloy plate was obtained.

The mechanical properties of the material thus obtained are shown in Table 3 below when compared with that of the same alloy obtained by the continuous casting method, and according to the present invention, it is stable. It has been confirmed that it is possible to produce the desired alloy plate and to obtain a product of desirable quality at low cost.

Table 3 Example 5, 1 t%, C: 0.32%, St: 0. 2%, M
n: 0.81%, p:o. ot%, S: 0.003
%,Aj! : 0.001%, N: 0.01% and the remainder is F
A 1550°C molten metal made of ordinary mild steel (e) was placed in the tundish 1, and the same tundish nozzle and strip gas nozzle as in Example 1 were employed in the same manner.

Surface roughness R2 = 100μ for rotating substrate 6
It was the same as in Example 1 in that a copper material with a diameter of 1.5 mm was used, and the rotational speed and axial movement speed were also the same as in Example 1, and the league strip was also the same as in Example 1. .

The obtained deposited sotocoil 8 is the same as in Example 3,
The rolling mill 10 performs rolling at a rolling reduction rate of 60% to reduce the plate thickness to 2. 0
A mild steel plate of ms was obtained.

The mechanical properties of the product obtained in this way are compared with those obtained by the normal casting method using the same normal mild steel, as shown in Table 4 below. According to the present invention, the mechanical properties are It has been confirmed that the desired mild steel plate can be manufactured at a lower cost than by conventional methods.

Table 4 "Effects of the Invention" According to the present invention as explained above, it is possible to directly and stably produce a wide thin plate material from molten metal, which was difficult in the prior art, and to form fine crystal grains. This invention has the effect of achieving fine and uniform dispersion of precipitates and producing products of excellent quality with little segregation, and is a highly effective invention industrially.

[Brief explanation of drawings]

The drawings show the technical content of the present invention, and Fig. 1 is an explanatory diagram showing an overview of the manufacturing method of the present invention, and Fig. 2 shows the relationship between the rotational speed and axial movement distance of the rotating substrate. FIG. 3 to FIG. 5 are explanatory diagrams of the prior art, respectively, and FIG. 6 is a diagram of the width shrinkage behavior of the curtain-shaped molten steel in the conventional method shown in FIG. However, in these drawings, 1 is a tundish, and 2 is a tundish.
is the molten metal, 3 is the tundish nozzle, 4 is the molten metal column,
5 is a rotating roll, 6 is a rotating substrate, 7 is a mandrel, 8 is a deposit coil, 9 is a payoff reel,
10 is a rolling mill, l1 is a take-up reel, Vr is a rotating substrate speed, Va is an axial movement speed thereof, Ws is a temporary width, and Wd is a deposit width.

Claims (1)

[Claims] A gas jet stream is blown onto the molten metal flowing out of the nozzle, or a metal particle stream is formed using rotating rolls.
depositing the metal particle stream on the axially reciprocating substrate to form a coil, and paying off the coil from the axially reciprocating rotating substrate;
A method for manufacturing a thin metal sheet, characterized by hot rolling as it is by utilizing the temperature of the material, or cold rolling after cooling.