SU1311844A1 - Method of semi-continuous casting of nickel - Google Patents

Abstract

This invention relates to metallurgy, in particular to semi-continuous nickel casting. The goal is to increase yield and improve the quality of the ingot. The pre-deoxidized metal is poured into the mold with a submerged jet, and the slag-forming mixture consisting of 50-60% sodium octoate and 40-50% of portland cement is placed on the metal mirror. The flow of water Q to cool the ingot and the speed of drawing are determined by the formulas Q B-S-W; W 0.15 + j, 2 where S is the section of the ingot, m; W — ingot extrusion rate, m / min; a (3.5-5.0) - 10 V 4.0- 8.5, 2 s, n, f-crystals. g kn 1 1

Description

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This invention relates to metallurgy, in particular to semi-continuous nickel casting.

The purpose of the invention is to increase the yield and improve the quality of the ingot.

The method is carried out as follows.

The metal, previously deoxidized at a temperature of 1600–1630 ° C, is poured into the crystallizer under the level through an elongated glass in order to avoid contact of the liquid melt with the environment. A slag-forming mixture consisting of 50-60% sodium oktoborate and 40-50% portland cement is placed on the metal mirror.

If the slag obtained after melting the mixture, which is placed on the metal mirror in the crystallizer, has a lower melting temperature, due to its very high fluidity, it is not retained on the surface of the molten metal in the crystallizer and does not perform the function of protecting it from oxidation by the surrounding atmosphere and from premature cooling. . Slags with a melting point above 1000 ° C are excessively viscous. As a result, their use as a lubricant is deteriorating, which leads to the ingot surface contamination with coarse slag inclusions. The use of a slag-forming mixture consisting of 50-60% sodium oktoborate and 40-50% portland cement, allows to obtain slag, which provides reliable protection of the metal mirror in the crystallizer against secondary oxidation and cooling and has sufficiently high lubricating characteristics.

When the ingot is pulled out of the crystallizer at a rate less than the lower limit of the velocity interval defined by the above formula, the surface quality of the ingot is obtained unsatisfactory due to the formation of non-nitrin. If the drawing speed exceeds the upper limit, then breakthroughs of the liquid metal are possible due to the insufficient thickness of the hardened crust when the ingot leaves the crystallizer.

When the water consumption for the secondary cooling of the ingot is less than the lower limit determined by the specified formula, a crust breakthrough is possible

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solidified metal resulting in

emergency stop casting. If the water consumption for the secondary cooling

exceeds the upper limit, this leads to the formation of cracks in the axial part of the ingot.

Primer p. The method of semi-continuous casting of nickel was tested when casting an ingot with a diameter of 163 mm. The metal was preliminarily deoxidized in an induction furnace at a temperature of 1610 ° C with manganese in an amount of 0.03% and with aluminum in an amount of 0.23% by weight of the basic charge materials.

Nickel is poured into the mold through an elongated glass in a submerged stream. A slag-forming mixture consisting of 55% sodium oktoborate and 45% portland cement is placed on the surface of the liquid metal in the crystallizer. By melting the mixture, slag is obtained with a melting point. The ingot from the mold is pulled at a speed

0.35 m / min, and the secondary cooling water consumption is 3.6 m / h. An ingot with a length of 3.6 m is cast, which is cut to length. Depth of the shrinkage shell in the head

part of the ingot is less than 1% of the total length of the ingot. The rest of the ingot has a dense macro- structure. The ingot surface quality is high,

i The proposed method of semi-continuous casting of nickel reduces the nickel waste during rolling, increases the yield of the ingot and improves its quality, as well as

reducing the likelihood of aborting.

Claims (1)

1. A method of semi-continuous casting of nickel, including the supply of metal to the crystallizer, the supply of slurry-forming mixture to the meniscus of the metal, cooling of the ingot under the crystallizer and its drawing, characterized in that, in order to increase the yield of the suitable and improve the quality of the ingot, the water consumption for cooling and drawing speed the ingot is interconnected by ratios; q B S-W; W 0.15 + |, 3 1311844-4 where Q is the flow of water for cooling2, the method according to claim 1, excellent as an ingot, m / min; u i and so that the supply of metal W = pulling rate of the fusion — performed below the level ka, m / min; 3. The method according to paragraphs. 1 and 2, о t S - ingot section area, m; j, which is used as a factor of (3.5-5.0) used as a slag-forming mixture of 10 m / min; a mixture of 50-60% octroborate of - 4.0-8.5.ri and 40-50% of portland cement.