Method for controlling quality of water turbine guide vane casting through double-loop conductive crystallizer electroslag remelting

Abstract

The invention discloses a method for controlling the quality of a water turbine guide vane casting through electroslag remelting of a double-loop conductive crystallizer. The method comprises the specific steps that (1) slag materials are baked; 2) determining the slag quantity and the filling ratio of the upper crystallizer and the lower crystallizer; a bottom pad and a lower crystallizer are placed, and an arcing material is bound to an electrode end; (3) switching on a power supply, starting to add slag, and arcing to melt slag; (4) after all the slag materials are melted down, the remelting current and voltage are adjusted and set, and electroslag remelting in the lower crystallizer is carried out; (5) after the electroslag in the lower crystallizer is remelted, an upper conductive crystallizer is installed, electrodes are replaced, the remelting current and voltage are adjusted and set again, and electroslag remelting is conducted through a double loop of a power source, a consumable electrode, slag charge, a metal molten pool, a casting, a bottom water tank, a power source and a double loop of the power source, the consumable electrode, the slag charge, the upper conductive crystallizer and the power source; and (6) in the later stage of remelting, after feeding operation of the electroslag remelting point is stopped, power is cut off, and a remelted water turbine guide vane casting is obtained through cooling. By adopting the method, the water turbine guide vane casting with good surface and internal quality can be obtained.

Description

technical field [0001] The invention belongs to the technical field of special electroslag metallurgy, and in particular relates to a method for controlling the quality of a water turbine guide vane casting by electroslag remelting of a double-circuit conductive crystallizer. Background technique [0002] As an important branch of electroslag metallurgy, electroslag remelting integrates melting, refining, solidification and near-final forming. It is one of the important methods to produce high-quality castings. It has the ability to remove non-metallic inclusions and reduce the content of harmful elements. , control the crystallization direction, and make the castings solidify sequentially from bottom to top. Compared with traditional casting methods, electroslag castings have inherent quality advantages that cannot be compared with ordinary die castings. [0003] During the development of electroslag remelting water turbine guide vane casting technology, the variable sectio...

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Problems solved by technology

[0005] In order to solve the problems of difficult process design, poor process stability and high production cost of the traditional electroslag remelting hydraulic turbine guide vane method, the present invention provides a method for controlling hydraulic turbine guide vanes using double-circuit conductive crystallizer electroslag remelting technology. Casting quality method, this method can obtain shallow and flat metal molten pool, reduce the segregation degree of elements, reduce slag groove and shunt defects, so as to effectively guarantee the surface quality and solidification quality of turbine guide vane castings

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