JPS63119954A - Ultrasonic oscillating mold for continuous casting - Google Patents

Abstract

PURPOSE:To easily and quickly form a protecting layer having excellent cavitation resistance and corrosion resistance by forming the protecting layer by plating a material having high hardness on a wall face facing the space for flowing through the cooling water in a mold body. CONSTITUTION:On the outer face of inner circumferential wall, that is, at the part facing on the cooling water room 1a of mold body 1 to which the end part of oscillating transferring rod 2 is fixed, the protecting layer 10 is formed as sticking to the prescribed thickness (10mum-1mm) by the plating around the whole in the prescribed range upward and downward as centering the connecting position of end part of oscillating transferring rod 2. As the protect ing layer 10, the material having higher hardness than copper, which is ordinar ily used as the mold body 1, and good adhesion with the copper, for example, nickel-boron, nickel-phosphorous, etc., is used. In this way, the formation of protecting layer is easily and quickly executed.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an ultrasonic mold for continuous casting in which the mold body is vibrated using ultrasonic waves in order to prevent the mold from sticking to the molten steel during the continuous casting process. This invention relates to sonic vibration molds.

[Prior art]

Generally, this type of mold body is formed into a hollow rectangular or circular ring shape with a cooling water chamber inside, but the means for applying ultrasonic vibration to the mold body is by penetrating the outer peripheral wall of the mold body. The tip of the vibration transmission rod is connected to the outer peripheral surface of the inner peripheral wall, that is, the inner surface of the cooling water chamber, at a portion approximately corresponding to the meniscus position, and an ultrasonic vibration device is attached to the base end of this vibration transmission rod. The vibration of the ultrasonic vibration device is transmitted to the inner peripheral wall of the mold body through a vibration transmission rod, and the mold body is vibrated with a predetermined amplitude (Japanese Patent Laid-Open Nos. 56-11155 and 1983). -96431, JP-A-57-58954, JP-A-57-62842)
.

However, in such a configuration, when ultrasonic vibration is caused while water is flowing through the cooling water chamber, grooves and grooves are formed on the inner peripheral surface of the cooling water chamber.
Alternatively, hole-like erosion may occur, and especially in areas where vibration and amplitude are large, the number and degree of erosion may be large, potentially leading to destruction of the mold body.

The cause of this kind of erosion is cavitation that occurs in the cooling water. In other words, negative pressure is generated in the cooling water, pores are generated in the water, and when these pores vibrate and are crushed, shock waves are generated and the pores are crushed. This is thought to be due to a phenomenon in which the inner circumferential wall surface of the cooling water chamber of the mold body in contact with the mold body erodes.

Therefore, as a means to prevent such erosion due to cavitation, conventionally, 4Z bronze was applied to the inner peripheral wall of the area where cavitation is particularly likely to occur, such as the narrow part of the cooling water chamber.

A method of welding a metal plate with excellent corrosion resistance against cavitation such as Mn bronze, Be bronze, or carbon steel 2 alloy steel (Japanese Patent Application Laid-Open No. 197348/1983), or a method of welding a metal plate with excellent corrosion resistance against cavitation, such as Mn bronze, Be bronze, or carbon steel 2 alloy steel, or a method of welding a metal plate with excellent corrosion resistance against cavitation, such as Mn bronze, Be bronze, or carbon steel 2 alloy steel. 7. A method of filling and interposing polyurethane, rubber, etc. as a material (Japanese Patent Application Laid-open No. 197351/1983) has been adopted.

[Problem that the invention seeks to solve]

However, with such conventional means, the protective member is fixed by welding, etc., and the installation itself requires a lot of effort, especially when it comes to the circular annular mold body used when casting billet materials etc. In this case, there is a problem in that it is extremely difficult to process for installation, and methods using polyurethane or the like have low durability and heat resistance, making maintenance and inspection troublesome.

The present invention has been made in view of the above circumstances, and its purpose is to provide an ultrasonic casting method for continuous casting that allows a protective layer with excellent cavitation erosion resistance to be easily and quickly formed at necessary locations. To provide vibration molds.

Means for Solving Problem C] In the present invention, the protective layer is formed by plating a material harder than the material of the mold body.

[Effect]

According to the present invention, it is possible to form a uniform protective material regardless of whether the target area requiring a protective layer is wide or narrow, or has a surface texture.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof. FIG. 1 is a schematic cross-sectional view of an ultrasonic vibration mold for continuous casting according to the present invention (hereinafter referred to as the product of the present invention), in which 1 is a mold body, 2 is a vibration transmission rod, 3 is an ultrasonic vibration device,
4 indicates a submerged nozzle.

The mold body 1 is formed into a hollow annular shape with a cooling water chamber 1a inside. Molten metal 5 is injected into the inside of the mold body through an immersion nozzle 4, and in the process of descending inside the mold body 1, it is mixed with the mold body l. It is cooled by heat exchange to form a solidified shell 6, which becomes a slab 7 and is continuously drawn downward by a roll gang 8.

The vibration transmission 402 is made of gold B and is formed into a bar shape, and its tip end with an end strip is inserted into the hole 1b drilled in the outer peripheral wall of the mold body 1 at a plurality of positions in the circumferential direction of the mold body 1, respectively. A screw hole is inserted into the inner peripheral wall facing the cooling water chamber 1a, which is a space for cooling water circulation, and formed in the inner peripheral wall at a portion corresponding to the meniscus position or in the vicinity thereof. The ultrasonic vibrating device 3 is attached to the base end, and the vibration of the ultrasonic vibrating device 3 is transmitted to the inner circumferential wall of the mold body 1 via the vibration transmission rod 2. The inner circumferential wall of the wall is vibrated in a direction perpendicular to the wall surface.

In the product of the present invention, the outer surface of the inner peripheral wall of the mold body to which the tip of the vibration transmission rod 2 is fixed, that is, the cooling water chamber 1
On the part facing a, protective Ni0 is deposited to a required thickness of 10 μm or more by plating over the entire circumference in the required range upwards and downwards centering on the connecting position of the tip of the vibration transmitting rod 2. be. The mold body 1 serves as the protective layer 10.
Materials that have a hardness higher than that of copper (Vickers hardness, the same applies hereinafter) and that have good adhesion to copper, such as nickel-boron (Ni: 93-95%, B:
5-7%), nickel-bond (Ni: 90-92%)
, P: 8-10%), etc. are used.

By the way, I shown in Japanese Patent Application Laid-Open No. 59-197348
The hardness of n' bronze is about 100-150, and the hardness of the mold body 1 made of Be bronze is about 400-500, while the hardness of nickel-boron is about 975-1075 and that of nickel-phosphorus is about 1100.

The thickness of the protective layer IO needs to be 10 μm or more in order to obtain sufficient erosion resistance against cavitation, and the upper limit of the thickness is within the range that can be formed by normal plating, but usually about 1 fi is sufficient for strength. It is sufficient for the purpose.

Next, comparative test results for the product of the present invention and a comparative example will be shown. The sample of the product of the present invention is the first one made of Cu (hardness: 100).
The mold body as shown in the figure (inner diameter: 320n, length: 900m)
A vibration transmission rod is connected to two locations on the inner wall surface of the cooling water chamber (mm, wall thickness: 15fi), and various metals are coated over the entire circumferential surface in the required range above and below, including the connection position of the vibration transmission rod. After plating to form a protective layer, each mold body has a thickness of 25 to 30 μm relative to the ultrasonic application area.
20 above and below, including the position corresponding to the meniscus position.
After casting a billet while applying vibration to the portion extending over 0 nm with an amplitude of about 5 μm or more, the cavitation erosion resistance was examined. Note that the test conditions were the same for the comparative examples. The results are shown in Table 1.

As is clear from Table 1, the product of the present invention, which is plated with a relatively hard metal as a protective layer, was continuously cast for several months, but no corrosion was observed and the product had good corrosion resistance. The results were obtained.

In addition, when the protective layer shown as a comparative example is not provided, the total casting time is about 100 hours, and several tens of points with a width of 0.5 to 1 fi and a depth of 0.5 to 1.0 mm are formed around the ultrasonic application area. Erosion in the form of stripes and stripes was observed.

In addition, when the protective layer was simply formed of Ni plating, corrosion was observed in several places after a total casting time of about 100 hours, which was thought to be caused by insufficient hardness.

(The following is a blank space) Table 1 [Effects] As described above, in the product of the present invention, since the protective layer is formed on the peripheral wall surface of the cooling water flow space by plating, it is extremely easy to form the protective layer. It can be performed quickly, has excellent workability for forming a protective layer, and can be formed to the required thickness without worrying about the width or narrowness of the area to be formed or the surface properties, resulting in high reliability. The present invention has excellent effects such as:

[Brief explanation of the drawing]

Figure 1 is a schematic cross-sectional view showing how the product of the present invention is used;
The figure is a partially enlarged view. 1... Mold body 1a... Cooling water chamber 1b... Hole 1c... 0 ring 2... Vibration transmission rod 3... Ultrasonic vibration device 4... Immersion nozzle 5... Melting Metal 6... Solidified shell 7... Slab 8... Rollgang 10... Protective layer patent Applicant Sumitomo Metal Industries Co., Ltd. Agent Patent attorney Noboru Kono 1 Figure 2

Claims (1)

[Claims] 1. The wall surface facing the space for cooling water flow inside the mold body equipped with means for applying ultrasonic vibration is plated with a material harder than the material of the mold body to prevent cavitation erosion. An ultrasonic vibration mold for continuous casting, characterized by forming a protective layer for continuous casting. 2. The protective layer is made of Ni-B alloy (Ni: 93-95%,
The ultrasonic vibration mold for continuous casting according to claim 1, which is made of B:5 to 7%) and formed to have a thickness of 10 μm to 1 mm. 3. The protective layer is made of Ni-P alloy (Ni: 90-92%,
The ultrasonic vibration mold for continuous casting according to claim 1, which is made of P: 8 to 10%) and formed to have a thickness of 10 μm to 1 mm.