JPS58154438A - Casting method of steel and vessel for molten metal - Google Patents

Abstract

PURPOSE:To improve the yield of casting by casting the steel added with alloy components of high specific gravity after removing or while removing the molten metal part contg. said alloy components settled on the bottom of a vessel for molten metal thickly. CONSTITUTION:A ladle 1 provided with, for example, two pieces of nozzles 11A and 11B in the bottom respectively at different heights of openings 12A and 12B is used as a vessel for molten metal. Then, the parts of the molten metal contg. alloy components of high specific gravity thickly accumulate in the lower space 13 of the ladle 1; therefore, if the nozzle 11A is opened, only the said parts can be removed. Since the molten steel having required compsn. can be tapped by opening the other nozzle 11B, the removal of the undesirable molten metal and the casting of the steel are progressed simultaneously.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is an improvement in the method of casting steel with added alloying components of high specific gravity, and also includes a molten metal vessel suitable for use in carrying out the method. The present invention has great significance especially when applied to continuous casting.

For example, in the production of lead free-cutting steel, a predetermined amount of lead is added to molten steel, which has been melted and refined to adjust other components, in a ladle, and then cast.

However, it is often experienced in actual operations that the Pb content in the cast body is quite different from that in the hot metal sample. The reason is that Pb has a high specific gravity ((1134)
, some of the added material sinks to the bottom of the ladle in a molten state and forms a layer of molten metal containing a large amount of solids (5). It was found that when the nozzle at the bottom of the ladle is opened and the molten metal is poured out, the molten metal containing a certain amount of molten metal (January 2012) also flows out along with the bath water of the specified composition, so that the entire product meets the specifications. This results in alloy compositions that do not match.

This problem is particularly serious when copper is continuously cast; by the time the molten metal containing a high concentration of PI is reached, a substandard slab is formed for a considerable length.
Since this has no choice but to be discarded, the yield will be low.

This problem is not limited to Pb, but is common when adding high specific gravity elements such as [3I (specific gravity 978).

As a countermeasure to this problem, the present inventors have either removed in advance the part of the molten metal containing a high concentration of high specific gravity alloy components that has sunk to the bottom of the molten metal container, or added high specific gravity alloy components while removing it. This proposal proposes the casting of steel that is

Here, the term "molten metal container" includes not only a ladle but also a tundish used in continuous casting, which is used while supplying lmhil melted in a furnace to an ingot case or a water-cooled mold. means all containers.

To explain a typical mode of carrying out the above method using existing equipment in the case of continuous casting, first, as shown in FIG.
Layer 9 containing a high concentration of the four high-polymerization components such as PB under the layer 9
The main winding wire 71 and the auxiliary winding wire 7 are hanging the ladle using an auxiliary crane.
By adjusting the height of the pull from the pouring nozzle 11, the opening of the pouring nozzle 11 is tilted to a low position, and the portion containing the high specific gravity alloy component listed in 1- is concentrated there. Open the nozzle 11 (・Take out the lever part preferentially and pass it through the movable waste water and (・5) to receive it in the waste water container 6.

When a portion of molten metal containing a high concentration of PB etc. is found, as shown in Fig. 2, immediately remove the drain 5 and remove the slope of the ladle to remove the molten steel with a predetermined composition. The tongue tissue 2 is supplied to the mold 4 through the immersion nozzle 3, and continuous casting is started.

As mentioned above, the present invention also encompasses a molten metal vessel suitable for use in carrying out the casting process.

The first type is characterized in that the area around the opening 12 of the nozzle 11 is formed lower than other areas at the bottom of the ladle 1, as shown in FIG. 3, which takes the example of a ladle. shall be. In this way, the part of the molten metal that contains high specific gravity alloy components will naturally gather near the opening of the nozzle, so when the nozzle is opened, it can be taken out preferentially. There is no need to tilt the head.

In the second type, as shown in FIG. 4, which also takes a ladle as an example, two nozzles IIA and IIB are installed at the bottom of the ladle 1, with respective openings 12A and 1211.
3 are provided at different heights. As is easily understood, the portion of the molten metal that contains a high density alloy component is collected in the lower space 13 at the bottom of the ladle, so that only that portion can be taken out by opening the nozzle 11A. By opening the other nozzle 11.8, molten steel having a predetermined composition can be poured out, so that removal of undesirable molten metal portions and casting can proceed at the same time.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views illustrating one embodiment of the method of the present invention applied to continuous casting. Figure 2 does not show the step of removing the containing portion, nor does it show the subsequent continuous casting step. 3A and 3B show an example of the first type of molten metal container of the present invention, in which A is a sectional view and B is a plan view. 2 shows an example of the second type of molten metal container, in which A is a cross-sectional view and B is a plan view. 1. Ribe 11, IIA, IIB. Nozzle 12, 12A, 12B. Nozzle opening 2-
Tongue tissue 3- Immersion nozzle 4, mold 5, waste water channel 6, waste water container 8, molten steel 9, molten metal richly containing high specific gravity alloy components Patent applicant Daido Steel Co., Ltd. Agent Patent attorney Souo Suga 1'"1 ,, - Age 1 Figure 11A 11B Age 3 Figure B 3 Age 4 Figure B

Claims (1)

[Claims] (1) When casting steel to which high specific gravity alloy components have been added, the portion of the molten metal that has sunk to the bottom of the molten metal container and is rich in high specific gravity alloy components is removed in advance. A method for casting lead, which is characterized by casting after or while removing lead. (2) The casting method according to claim 1, wherein the high specific gravity alloy component is PB or B1, which has a low melt viscosity. (3) Tilt the molten metal container so that the opening of the pouring nozzle is lower, concentrate there the part of the molten metal that contains high specific gravity alloy components, and open the nozzle to prioritize this part. The casting method according to claim 1, wherein casting is started after the casting is taken out. (・1) A molten metal container used when casting steel to which alloy components of high specific gravity are added, characterized in that the part around the nozzle opening is lower than the other parts at the bottom of the container. container. (5) A molten metal container used when casting steel to which alloy components of high specific gravity are added, characterized by having two nozzles at the bottom with different opening heights. patent