Air-cooled semi-continuous casting system and method of high-activity alloy

Abstract

The invention relates to an air-cooled semi-continuous casting system and method of a high-activity alloy. The system comprises water-cooled crystallizers, air injection devices, an air-cooling device, an air tank, and a casting device, wherein the water-cooled crystallizers are located above the air injection devices; each air injection device is composed of an air injection ring, an air nozzle, and an air guide plate; the air injection devices are connected with the air cooling device and the air tank in order. The method comprises the following process steps: (1) checking leakproofness and unobstruction of the system, and adjusting angles of the air nozzles; (2) enabling dummy ingots to extend into the water-cooled crystallizers; directing an alloy melt to flow into a cavity, turning on a casting machine, adjusting a casting speed, and controlling a temperature of cooling air and adjusting a flow velocity of the air; and (3) when a length of an ingot blank meets a requirement, stopping melt supply firstly, closing a flow control valve after the melt in the water-cooled crystallizers is gradually cooled and solidified, and after an upper surface of the ingot blank is lowered down to a position below secondary cooling air injection devices, removing the water-cooled crystallizers and the secondary cooling air injection devices, lifting out the metal ingot blank, and then finishing casting.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a high-activity alloy air-cooled semi-continuous casting system and method. Background technique [0002] Semi-continuous casting is the main method for producing round billets and slabs of non-ferrous metals. During the production process, the smelted metal melt is cast into the cavity formed by the dummy ingot and the crystallizer, and after a stable solidified shell is formed around it, The ingot moves down with the dummy ingot, and the molten metal is poured into the mold at the same time, and the surface of the ingot exposed to the mold is rapidly cooled by the impact of cooling water. Under the dual cooling effect of the inner wall of the mold and the impact of cooling water, The ingot gradually solidifies and is continuously pulled out of the crystallizer to become a slab or round billet whose cross-sectional shape and size are consistent with the inner slee...

AI Technical Summary

Problems solved by technology

If the semi-continuous casting method is used to produce the ingot for calcium alloy extrusion, the quality and production efficiency of the ingot can be significantly improved, but due to the high activity of calcium and its alloys, it is easy to generate calcium hydroxide and hydrogen when it contacts with water at room temperature (Ca+2H 2 O=Ca(OH) 2 +H 2 ↑), especially when the newly solidified calcium is impacted by cooling water, this reaction is more violent, the reaction speed is fast, and a large amount of hydrogen gas is released, which diffuses into the surrounding gas, which can easily cause an explosion at the casting site

[0005] Therefore, high-activity alloys such as magnesium-lithium alloys and calcium alloys cannot be produced by traditional direct water-cooled semi-continuous casting methods, and the method of die casting cannot reach industrial production in terms of production efficiency, product quality and economic cost. There is an urgent need for a new method to produce this highly active alloy billet similar to magnesium-lithium alloys and calcium alloys

[0006] In response to this problem, foreign researchers have tried to a certain extent. In the patent US4709470, organic coolants are used to produce magnesium-lithium and aluminum-lithium alloys. The organic coolants used include ethylene glycol, glycerol, and vegetable oil. And in this patent, the heat exchange efficiency of the organic coolant used was measured, but the organic coolant used has certain toxicity or flammability, and it is easy to splash and volatilize when it hits the surface of the high-temperature billet, so it has been used many times. It will cause harm to the body of the operator and the surrounding environment, so although this method is theoretically feasible, it has not been applied in the actual production process

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