JPS60103113A - Method for adding lead to molten steel - Google Patents

Abstract

PURPOSE:To add uniformly lead to a molten steel at a good yield in the stage of adding the lead to the molten steel poured into a mold for continuous casting by adding the lead together with carrier gas to the fall mouth formed to the molten steel in a tundish. CONSTITUTION:The molten steel 2 in a ladle 1 is tapped through an immersion nozzle 4 into a tundish 5 when a sliding nozzle 3 is opened. The molten steel flowing down into the tundish 5 collides against the molten steel in the tundish 5, thereby forming turbulent flow and a fall mouth 6. A lance 7 is inserted into the mouth 6 and granular lead is ejected by carrier gas consisting of inert gas such as Ar toward the port 6, by which the lead is added to the molten steel. The added steel is quickly melted by the vigorous stirring effect of the mouth 6 and the stirring effect of the molten steel by the carrier gas and is thus quickly diffused into the molten steel.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for adding lead uniformly and with a high yield to mM injected into a mold for continuous casting, and more specifically, when tapping molten steel from a ladle into a tundish. It relates to a method of adding lead together with a carrier gas to a type 80 of the present invention.

Lead is generally known as an additive element when melting free-cutting steel, etc. Conventionally, the method of adding lead to molten steel is as follows:
Methods of adding lead to molten steel that is being tapped or stored in a ladle or tundish, and methods of adding lead to the molten steel flow that is being tapped into a mold. Among these methods, if an anchor is added to molten steel while it is being tapped or stored in a ladle or tundish, the specific gravity of lead is greater than that of molten steel, so the lead settles to the bottom of the ladle or tundish, and the lead content increases. Significantly lower yield,
Moreover, there is a problem in that lead is not uniformly dispersed in the molten steel, and lead segregates in the resulting ingot or billet. In addition, when lead is directly added to the molten steel flow being tapped at the mill, the added lead is melted in 1'ηM and the molten steel is thoroughly diffused into the JJ mold. Since lead is injected into the ingot or billet, lead segregation in the ingot or billet was a problem.

The purpose of the present invention is to solve the problems of these conventional methods and provide a method capable of adding lead uniformly and with high yield to molten steel poured into a continuous casting mold. However, when the molten steel is tapped from the ladle into the tundish, lead is added to the tundish with a lance inserted into the molten steel trough along with a carrier gas (7+: yes).

The present invention will be explained below with reference to Figure 7'ef3.

As shown in FIG. 2, the melt 2 in the molten metal 1 is discharged from the immersion nozzle 4 into the tundish 5 by opening the sliding nozzle 3.

The molten steel flowing down into the tanditshu 5
It collides with the molten steel inside, creating a turbulent flow.
Form. A lance 7 is inserted into the opening 6 of the molten steel in the molten steel 5 from the upper and outer side of the molten steel 5, and the granulated tG (containing lead alloys and lead compounds) is heated with a gear gas consisting of an inert gas such as argon gas. 'l
'4 Mk Add lead by injecting it towards the roller.

(Then, the lead ejected by the carrier gas to No. 64 Takiguchi 6 in Tandish 5 is rapidly understood and quickly diffused into the molten steel by the intense ML stirring action by the Takiguchi 60d car and the molten steel stirring action by the carrier gas. Furthermore, even after the granular lead has been spouted, the carrier gas from the lance 7 may be continued to be injected, or additional gas may be blown from a separate blow port provided at the I+C section of the mendices 5 to complete the mendices. e-nitrate in 5
The mixture may be further stirred for 4n.

The molten steel in which molten lead has been uniformly diffused is then tapped into a tundish 5 or a mold 8. This Hl, a field is inside the kundish (f +
Although the present invention provides a method of adding lead to molten steel, the present invention also provides a method for adding lead to molten steel. , e.g. bismuth, Arles, selenium 5°T
It will be easily understood that it can also be applied to cases where tungsten, molybdenum, niobium, vanadium, etc., which have a higher specific gravity than # steel, are added to the molten d11.

Next, the results of adding lead to the structural carbon J group according to the method of the present invention and the conventional method are shown.

In a test in which molten metal was poured into a mold from a tundish, the method of the present invention had a yield of 78%, whereas the conventional method of adding molten metal into a tundish had a yield of 40 to 50%.

As is clear from the above explanation, according to the present invention, the lead supplied to Tanditshu Takiguchi is 11f of molten steel.
The dissolution is promoted by the pushing action and the stirring action of the carrier gas, and the dissolved lead is evenly dispersed in the tundish (1), and lead is prevented from precipitating out at the bottom of the tundish, resulting in an improved lead yield. A method of adding is provided.

[Brief explanation of the drawing]

The drawings are explanatory diagrams showing an example of the case where the present invention is implemented. 1... Ladle 2... Molten steel 3... Sliding nozzle 4... Immersion nozzle 5
...Tanditshu 6...Waterfall Roa...Lance 8...Mold

Claims (1)

[Claims] 1. When adding lead to the molten steel injected into the continuous casting mold, when the molten steel is tapped from the ladle into the tundish, the lance inserted into the cascade formed in the molten steel in the tundish is used to add lead along with carrier gas to the tundish. Addition 1-
A method for adding lead to molten steel.