Method and device for improving quality of high-temperature alloy master alloy ingot by applying compound electromagnetic field

Abstract

A method and a device for improving the quality of a high-temperature alloy master alloy ingot by applying a compound electromagnetic field are disclosed, wherein two electromagnetic field generators are orderly arranged on the upper and lower parts of the outer side of an austenite stainless steel ingot mold, and a steady direct-current electromagnetic field generator is arranged at the upper part, while a bidirectional low-frequency alternating-current rotating electromagnetic field generator is arranged at the lower part; a low-frequency alternating current is input into the bidirectional low-frequency alternating-current rotating electromagnetic field generator at the lower part so as to generate a bidirectional rotating electromagnetic field; the bidirectional rotating electromagnetic stirring action produced by the bidirectional rotating electromagnetic field in the metal liquid is capable of causing the central shrinkage cavity zone of the high-temperature alloy master alloy ingot to be reduced and moved up, the content of impurities to be reduced, dendritic segregation to be reduced, and a solidification structure to be thin and even; a direct current is input into the steady direct-current electromagnetic field generator at the upper part so as to generate an even direct-current electromagnetic current; and the electromagnetic braking force generated at the metal liquid level by the steady direct-current electromagnetic field generator inhibits drastic fluctuation of the metal liquid level caused by electromagnetic stirring, and eliminates adverse effects of the fluctuation of the metal liquid level on the rising of the impurities and the feeding of the shrinkage cavity in the solidification process of the high-temperature alloy master alloy ingot.

Description

technical field [0001] The invention belongs to the field of metal material preparation, in particular to the preparation of high-temperature alloy master alloy ingots. Background technique [0002] Superalloys can withstand large working loads for a long time under high-temperature oxidizing atmosphere and gas corrosion conditions of 600°C to 1100°C, and are important structural materials in industries such as aerospace, ships, power generation, and petrochemical industries. According to the production process, superalloys can be divided into four categories: deformation, casting, powder metallurgy and mechanical alloying. After the 1970s, with the development and application of smelting and casting technologies such as vacuum casting, investment casting, directional solidification, single crystal casting, and fine grain casting, a series of cast superalloys with higher performance appeared. Performance The development and application of cast superalloys meet the developme...

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Problems solved by technology

[0004] In 2008, in the article "Research on Vacuum Electromagnetic Casting Technology of K417 Superalloy Master Alloy Ingot" published in "Rare Metal Materials and Engineering", the applicant proposed the method of applying rotating electromagnetic stirring during the solidification process of superalloy metal liquid to cast superalloy master alloy The method of alloy ingot quality, which can refine the grain structure of superalloy master alloy ingot, improve the number and distribution of central shrinkage cavity and inclusions, and reduce dendrite segregation, but this method solves it by delaying the start time of electromagnetic stirring Rotating electromagnetic stirring immediately after the molten metal is poured into the mold will cause relatively large fluctuations in the level of the molten metal that has not formed a surface crust, and the molten metal will climb along the mold wall under the action of electromagnetic force and solidify to form a large flash, which will deteriorate The problem of feeding conditions for shrinkage cavities during the solidification of castings leads to the reduction of electromagnetic stirring time during the solidification of molten metal, so the scope and effect of electromagnetic stirring in master alloy ingots are limited

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