Method for smelting hollow billet steel ingot by using ingot stripping type electroslag furnace

Abstract

The invention discloses a method for smelting a hollow billet steel ingot by using an ingot stripping type electroslag furnace. An outer crystallizer, an inner crystallizer and a bottom water tank are arranged in the ingot stripping type electroslag furnace, and an annular electrode bar is arranged between the outer crystallizer and the inner crystallizer; liquid slag charge is added into the ingot stripping type electroslag furnace, and arc striking is performed for smelting; the normal smelting current is controlled to be 21,000-25,000 A, the normal smelting voltage is controlled to be 78-88 V, and the smelting speed of the annular electrode bar is controlled to be 14-22 kg/min; and when a smelt liquid steel level formed by smelting is located in the position of 1/2-2/3 of the height of a section used for solidifying liquid steel in the inner crystallizer, the bottom water tank is controlled to drive a steel ingot to move downwards for ingot stripping, the ingot stripping speed is controlled to be 3-16 mm/min, the downward friction force suffered by the inner crystallizer is controlled to be smaller than 40% of the minimum deformation force which can be borne by the inner crystallizer, and the hollow billet steel ingot is obtained after the steel ingot is completely stripped. The method can smelt the qualified hollow billet steel ingot, and the quality and the production efficiency of a pipe fitting are improved greatly.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, and more specifically, relates to a method for smelting hollow tube blank steel ingots in an ingot-pulling electroslag furnace. Background technique [0002] The smelting of electroslag furnaces in my country is mainly based on traditional electroslag furnaces (generally composed of arms, columns, short nets, transformers, ingot supporting trolleys, etc.) and protective atmosphere electroslag furnaces, and electroslag furnaces are usually used to smelt hollow tube billets The steel ingot needs to be perforated in a complicated way, and it is difficult to ensure the concentricity of the inner and outer holes and the uniformity of the wall thickness, which is detrimental to the quality and production efficiency of the pipe fittings. [0003] At present, ingot-pulling electroslag furnaces are gradually developing abroad, and the use of ingot-pulling electroslag furnaces to smelt hol...

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Problems solved by technology

[0002] The smelting of electroslag furnaces in my country is mainly based on traditional electroslag furnaces (generally composed of arms, columns, short nets, transformers, ingot supporting trolleys, etc.) and protective atmosphere electroslag furnaces, and electroslag furnaces are usually used to smelt hollow tube billets The steel ingot needs to be perforated in a complicated way, and it is difficult to ensure the concentricity of the inner and outer holes and the uniformity of the wall thickness, which is detrimental to the quality and production efficiency of the pipe fittings

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