JPS5825846A - Horizontal and continuous casting method - Google Patents

Abstract

PURPOSE:To improve the internal quality of an ingot easily with simple installations by casting the molte steel in a tundish while oscillating the same with an oscillator immersed therein. CONSTITUTION:The molten steel 3 in a tundish 1 flows through a front nozzle 4 and a field nozzle 5 into a mold 6. The steel 3 is cooled with the mold 6, and is further cooled with a break ring 7, thus gradually solidifying to an ingot. The ingot is drawn with pinch rolls 9 in conformity with the rate of solidification. Here, the steel 3 in the tundish 1 is oscillated with an oscillator 10, whereby the segregation and porosity generated in the central part of the ingot is improved. The inside of the oscillator 10 assumes the construction of double pipes. Cooling water is supplied into the outer pipe and is discharged from the inner pipe with a water supply and discharge pipe 13. The oscillator 10 is oscillated with an oscillating device 11 via an arm 12.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a horizontal continuous casting method, and particularly to a horizontal continuous casting method in which the internal quality of slabs is improved.

In recent years, progress in horizontal continuous casting of steel has been remarkable.

It has become possible to cast small cross-section square billets, square blooms, round billets, and round plumes. This type of horizontal continuous casting method has the following advantages: construction of casting equipment is low, maintenance is easy, casting is technically easy, so it can be automated and unmanned, and the external stress on the slab is theoretically low. Because it does not work, cracking defects are less likely to occur on the surface and inside of the slab.

Since the mold and the tundish are directly connected, it has advantages such as less inclusions due to air oxidation, so it is thought that the horizontal continuous casting method will be increasingly adopted in the future.

As the application of the horizontal continuous casting method is expanded to, for example, high-grade wire rods, steel bars, and high-grade seamless pipes, improvement of segregation and center porosity that occur at the center of the slab becomes an important issue. As a method for solving this problem, a method has been implemented in which unsolidified molten steel is electromagnetically stirred during the slab solidification process.

However, although the electromagnetic stirring method has certain effects, it has problems such as increased equipment costs, power costs, etc.

The present invention provides a horizontal continuous casting method that can easily improve the internal quality of slabs using simple equipment, in which a vibrating body is immersed in molten steel in a tundish, and the vibrating body is forced to FIG. 1 is also a block diagram illustrating one embodiment of the method of the present invention. −：Advanced first,
In Figure 1, 1 is a tundish, and 2 is a casting nozzle that injects molten steel 3 into the tundish 1.
・The rattle, 4, is fixed to the side wall of the tundish l. ・Front nozzle, 5, connected to the front nozzle 4. A vibration mold 8 is connected horizontally to a secondary cooling zone 9 following the mold 6.
i Segregation is pinch roll, 10 is in tundish 1 j le.

11 is a vibrating body immersed in molten steel;
In order to apply vibration to the vibrating body 10 via the progress member 12,
This is the 6th vibration device. The inside of the vibrating body IO has a double tube structure, and cooling water is supplied from the outer tube.
Cooling water is discharged from the inner side pipe. The cooling water is supplied and drained through all of the water supply and drainage pipes 13.

The molten steel 3 in the dish 1 passes through the front nozzle and the feed nozzle 5 and enters the mold 6. Molten steel 3 mold 6
When it is cooled, further cooling is promoted by the plate ring 7 and reaches the secondary cooling zone 8, where it is further cooled. In this way, the molten steel 2 gradually becomes a slab that does not solidify. The slab t is pulled out by pinch rolls 9 in accordance with the solidification rate of the molten steel 2.

The molten steel 3 in the dish 1 is vibrated by the vibrating body 1O. By initially applying molten steel 3 in this manner, it is possible to improve the center porosity that occurs at the center of the slab. Inflow molten steel 3
If you block it, you can expect a positive effect on vibrations.

The vibration of the moving body 10 is a high frequency micro vibration or several to several hundred vibrations.
A vibration of Hz is preferred. In the case of high-frequency minute vibrations, ultrasonic vibrations are most effective. However, excessive vibration is undesirable because it may excessively disturb the surface of the molten steel 3 in the tundish 1 and induce inclusions.

It is also possible to detect the temperature of the waste water from the vibrating body 10 with a thermocouple, monitor abnormal temperature rise, and automatically control the temperature to a desired temperature by adjusting the water amount.

In order to vibrate the vibrating body 10, in addition to vibrating the vibrating body 10 by using the vibrating device 11 provided outside the tundish 1 via the arm 12 as in the above-mentioned embodiment, the vibrating body 10 is vibrated directly by ultrasonic sound.
A wave oscillator may be embedded and vibrated.

The material of the vibrating body 10 is copper, copper alloy, stainless steel, or 1M70. -Gt-based, MgO--Cr2O3-based, or Mo-ZrO2-based refractories may be used.

Next, embodiments of the invention will be described.

Casting was carried out using an apparatus similar to that shown in FIG. 1 and according to the casting conditions shown in Table 1.

Table 1 i! ! ! .

Casting The first half of the casting process was carried out using the normal casting method, and the second half of the casting process was carried out by immersing the vibrating body in molten steel in a tamp bush close to the mold. After casting, slab samples were taken and their internal quality was investigated. As a result, only columnar crystals were present in the slab sample from the first half of casting, in which no vibration was applied to the molten steel, and center porosity was observed. On the other hand, in the slab sample in the latter half of casting, where the molten steel is subjected to vibration, only fine equiaxed crystals are present, and the center porosity has disappeared and the shape is round.

Below If

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the method of the present invention. l... Tanditshu 2... Casting nozzle 3...
Molten steel 4...Front nozzle 5...Feed nozzle 6...Mold 7...Break ring 8...Secondary cooling zone 9...Pinch roll
10... Vibrating body 11... Vibrating device 12
... Arm 13 ... Water supply and drainage pipe applicant Keitabe Tsutsumi (1 other person), agent of Nippon Koukan Co., Ltd.

Claims (1)

[Claims] By immersing a vibrating body in the molten steel in the tundish and forcibly vibrating the vibrating body, vibrations are imparted to the molten steel in the tundish! A horizontal continuous casting method characterized by performing casting.