An electroslag casting device for three-dimensional curved surface complex shape castings

Abstract

The utility model belongs to the field of electroslag casting, and is specifically an electroslag casting device for three-dimensional variable curved surface complex shape castings such as turbine generator blades. The device includes: a guide electrode, a flexible electrode, a casting bottom pad, a slag layer, a casting bottom pad and a crystallizer insulation layer, and a crystallizer. The specific structure is as follows: a guide electrode is provided in the crystallizer cavity of the crystallizer, and the upper end of the guide channel in the guide electrode is the flexible electrode inlet. The flexible electrode is arranged in the guide channel in the guide electrode through the flexible electrode inlet. A casting bottom pad is provided at the bottom opening of the crystallizer cavity. The lower part of the guide electrode and the flexible electrode corresponds to the casting bottom pad. The casting bottom pad and the lower end of the guide electrode and the flexible electrode are between the casting bottom pad and the lower end of the guide electrode and the flexible electrode. The utility model solves the problem of complex shape castings, and is particularly applicable to the manufacture of three-dimensional variable curved surface complex shape castings such as turbine generator blades by electroslag casting, and broadens the application scope of electroslag casting technology.

Description

Technical Field

[0001] The utility model belongs to the field of electroslag casting, in particular to an electroslag casting device for castings with three-dimensional curved surfaces and complex shapes such as turbine generator blades. Background Art

[0002] As a casting process that combines refining and forming, electroslag casting is currently widely used in the field of manufacturing castings with high quality requirements. The casting uses consumable electrodes as the casting raw material. The consumable electrodes are placed in the crystallizer. After power is applied, the electrodes complete the casting process in the molten slag layer. This process requires maintaining a process safety distance between the electrode and the inner cavity of the crystallizer. At the same time, the consumable electrode, as a conductor of the power supply system, is always energized with the molten slag layer. The heat generated by the current through the slag resistance melts the consumable electrode. During the melting process, the consumable electrode needs to continuously descend in the crystallizer to maintain the continuous melting process. The molten steel solidifies in the water-cooled crystallizer cavity. As the casting progresses, the consumable electrode gradually melts and fills the crystallizer cavity until the entire casting process is completed.

[0003] The castings produced by electroslag casting have the advantages of dense structure, few casting defects and high purity. Especially for the flow-through parts such as turbine generator blades, the electroslag casting process manufacturing method can greatly improve the service life and safety of the blades. However, since the electroslag casting process requires the consumable electrode to continuously descend in the cavity, the existing technology cannot be implemented in the electroslag casting of complex-shaped castings such as three-dimensional variable-curved blades. At present, the electroslag casting process can only produce castings with two-dimensional curved surfaces with a common cavity shape. For three-dimensional variable-curved special-shaped castings, the existing electroslag casting technology is not applicable. Therefore, the existing electroslag casting process cannot be used to manufacture three-dimensional variable-curved special-shaped castings, which limits the scope of application of the electroslag casting process.

[0004] The current process for castings with complex three-dimensional curved surfaces, such as turbine blades and paddle blades, is sand casting. This method has many casting defects, which affects the service life of the blades, and the product quality cannot meet the high requirements of users. For workpieces that need to be composited with different alloys of a certain thickness on the surface of the workpiece, the current electroslag casting process also has many limitations. Utility Model Content

[0005] The purpose of the utility model is to provide an electroslag casting device for three-dimensional variable curved surface complex shape castings such as turbine generator blades, to solve the technical problem that the active consumable electrode in the current electroslag casting process cannot be continuously lowered in the three-dimensional variable curved surface cavity crystallizer of the blade type, and the electroslag casting process cannot be maintained. A new type of consumable electrode system is adopted to expand the application field of the electroslag casting process.

[0006] The technical solution of the utility model is as follows:

[0007] An electroslag melting device for castings with three-dimensional variable curved surfaces and complex shapes, the device comprises: a guide electrode, a flexible electrode, a casting bottom pad, a slag layer, a casting bottom pad and a crystallizer insulating layer, and a crystallizer. The specific structure is as follows: a guide electrode is provided in the crystallizer cavity of the crystallizer, the upper end of the guide channel in the guide electrode is an inlet for the flexible electrode, the flexible electrode is arranged in the guide channel in the guide electrode through the inlet for the flexible electrode, a casting bottom pad is provided at the bottom opening of the crystallizer cavity, the lower parts of the guide electrode and the flexible electrode correspond to the casting bottom pad, and a slag layer is provided between the casting bottom pad and the lower ends of the guide electrode and the flexible electrode.

[0008] The electroslag casting device for three-dimensional curved surface complex shape castings has one or more straight guide electrodes or curved guide electrodes in the shape of the crystallizer cavity arranged in the electroslag casting crystallizer cavity. The guide electrodes are fixed relative to the crystallizer and have guide channels inside.

[0009] In the electroslag casting device for three-dimensional curved surface complex shape castings, the flexible electrode is a whole, wire-shaped or granular metal.

[0010] The electroslag casting device for three-dimensional curved surface complex shape castings is provided with a wrapping skin wrapped around the outside of the flexible electrode, or magnetism is added to the guide electrode and the flexible electrode therein to form a flexible electrode as a whole.

[0011] The electroslag melting device for three-dimensional curved and complex-shaped castings has a wrapping skin made of metal or non-metal. The metal skin is made of iron, steel or aluminum, or a metal material that has some or all of the same elements as the casting material. The non-metal skin is a non-metallic woven fabric or other form that can achieve a wrapping effect.

[0012] The electroslag melting device for three-dimensional variable curved surface complex shape castings is provided with a granular metal feeding hopper at the flexible electrode inlet, a guide electrode magnetizing mechanism is provided between the bottom of the granular metal feeding hopper and the flexible electrode inlet, the top of the granular metal feeding hopper corresponds to the granular flexible electrode conveying drive device, and the granular flexible electrode is arranged in a guide channel in the guide electrode through the granular flexible electrode conveying drive device, the granular metal feeding hopper, the guide electrode magnetizing mechanism, and the flexible electrode inlet.

[0013] The electroslag melting device for three-dimensional variable curved surface complex shape castings is also equipped with an arc-striking consumable electrode, one or more guide electrodes as fixed consumable electrodes, used together with one or more movable arc-striking consumable electrodes, and an arc-striking section is provided at the lower end of the vertical arc-striking consumable electrode, and the bottom of the arc-striking section corresponds to the bottom pad of the casting.

[0014] The design idea of ​​the utility model is:

[0015] According to the basic process requirements of electroslag casting, the utility model proposes an electroslag casting device for three-dimensional variable curved surface complex shape castings such as turbine generator blades. During the electroslag casting process, by arranging a guide electrode in the crystallizer, a solid flexible, filamentous or granular flexible electrode is conveyed in the guide channel of the guide electrode, so as to realize continuous conveying of electrodes to the electroslag casting area, meet the requirement of continuous conveying of consumable electrodes in the curved section, and by adding a wrapping skin to the surface of the filamentous and granular flexible electrode, or by magnetizing the guide electrode, magnetic adsorption is generated between the filamentous and granular flexible electrodes, so that the filamentous and granular flexible electrodes form an integral flexible electrode, and then can be controllably conveyed downward in the guide channel of the guide electrode that follows the shape of the curved cavity of the electroslag casting crystallizer, so as to maintain the progress of the entire electroslag casting process. Figure 1 As shown, the utility model provides a basic form of electroslag casting manufacturing structure for producing three-dimensional variable curved surface castings such as turbine generator blades by electroslag casting technology.

[0016] The advantages and beneficial effects of the utility model are:

[0017] The utility model is used for the electroslag casting device of three-dimensional variable curved surface complex shape castings such as turbine generator blades, solves the technical problem that the electroslag casting process of complex shape castings, especially three-dimensional variable curved surface complex shape castings such as turbine generator blades, cannot be carried out, increases the flexibility of the application of the electroslag casting process, and broadens the variety and range of castings that can be produced by the electroslag casting process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The schematic diagram of an electroslag casting device for castings with three-dimensional curved surfaces and complex shapes such as turbine generator blades is shown in the figure. In the figure, 1-crystallizer cavity, 2-guide electrode, 3-flexible electrode (filament or granular), 4-casting bottom pad, 5-slag layer, 6-casting bottom pad and crystallizer insulation layer, 7-flexible electrode inlet, 8-crystallizer.

[0019] Figure 2 The present invention is a schematic diagram of a flexible electrode in a guide electrode, which is a granular flexible electrode wrapped by a wrapping skin. In the figure, 2 is a guide electrode, 8 is a crystallizer, 9 is a granular flexible electrode wrapped by a wrapping skin, 10 is a safety gap, 11 is a guide channel, and 12 is a flexible connecting section.

[0020] Figure 3 A schematic diagram of a granular flexible electrode wrapped with a wrapping skin. In the figure, 13 is a granular metal; 14 is a wrapping skin.

[0021] Figure 4The schematic diagram of a guide electrode and a flexible electrode with a magnetizing mechanism is shown in the figure. In the figure, 1-crystallizer cavity, 2-guide electrode, 4-casting bottom pad, 5-slag layer, 7-flexible electrode inlet, 8-crystallizer, 15-granular metal feeding hopper; 16-guide electrode magnetizing mechanism; 17-granular flexible electrode conveying drive device; 19-granular flexible electrode.

[0022] Figure 5 The present invention is a schematic diagram of an electroslag casting device with an arc-starting consumable electrode, a guide electrode and a flexible electrode. In the figure, 1 is a crystallizer cavity; 2 is a guide electrode; 4 is a casting bottom pad; 10 is a safety gap; 18 is an arc-starting consumable electrode; 19 is a granular flexible electrode; and 20 is an arc-starting segment. DETAILED DESCRIPTION

[0023] like Figure 1 As shown, an electroslag casting device for three-dimensional variable curved surface complex shape castings such as turbine generator blades mainly comprises: a guide electrode 2, a flexible electrode 3 (filamentary or granular), a casting bottom pad 4, a slag layer 5, a casting bottom pad and a crystallizer insulating layer 6, and a crystallizer 8. The specific structure is as follows: a guide electrode 2 is arranged in a crystallizer cavity 1 of the crystallizer 8, the upper end of the guide channel in the guide electrode 2 is a flexible electrode inlet 7, the filamentary or granular flexible electrode 3 is arranged in the guide channel in the guide electrode 2 through the flexible electrode inlet 7, a casting bottom pad 4 is arranged at the bottom opening of the crystallizer cavity 1, a casting bottom pad and a crystallizer insulating layer 6 are arranged between the bottom of the crystallizer cavity 1 and the casting bottom pad 4, the lower part of the guide electrode 2 and the filamentary or granular flexible electrode 3 corresponds to the casting bottom pad 4, and a slag layer 5 is arranged between the casting bottom pad 4 and the lower end of the guide electrode 2 and the filamentary or granular flexible electrode 3.

[0024] like Figure 2 As shown, a flexible electrode is provided in the guide channel 11 in the guide electrode 2. The flexible electrode is a granular flexible electrode 9 wrapped in a sheath. The sheath is made of metal or non-metallic skin (the metal skin is made of iron, steel, aluminum and other materials, or metal materials with some or all the same elements as the casting material, and the non-metallic skin is a non-metallic woven material or other forms that can achieve a wrapping effect, etc.). The guide electrode 2 and the granular flexible electrode 9 wrapped in the sheath are arranged in the cavity of the crystallizer 8. A safe gap 10 is maintained between the guide electrode 2 and the inner wall of the cavity of the crystallizer 8. The granular flexible electrode 9 wrapped in the sheath is a structure in which segmented capsules are connected in sequence, and between adjacent capsules is a flexible connection section 12 formed by tightening a metal skin or a non-metallic skin. During the smelting process, the granular flexible electrode 9 wrapped in the sheath is transported to the smelting zone in the guide channel 11 in the guide electrode 2. The granular flexible electrode 9 wrapped in the sheath has the characteristics of being adaptive and bendable in the guide channel 11.

[0025] like Figure 3As shown, the sheath-wrapped granular flexible electrode may be a sheath 14 filled with granular metal 13 .

[0026] like Figure 4 As shown, a guide electrode 2 is provided in the crystallizer cavity 1 of the crystallizer 8, and the upper end of the guide channel in the guide electrode 2 is a flexible electrode inlet 7, a granular metal feeding hopper 15 is provided at the flexible electrode inlet 7, a guide electrode magnetizing mechanism 16 is provided between the bottom of the granular metal feeding hopper 15 and the flexible electrode inlet 7, the top of the granular metal feeding hopper 15 corresponds to the granular flexible electrode conveying and driving device 17, and the granular flexible electrode 19 is arranged in the guide channel in the guide electrode 2 through the granular flexible electrode conveying and driving device 17, the granular metal feeding hopper 15, the guide electrode magnetizing mechanism 16, and the flexible electrode inlet 7, a casting bottom pad 4 is provided at the bottom opening of the crystallizer cavity 1, and the bottom of the guide electrode 2 and the granular flexible electrode 19 corresponds to the casting bottom pad 4, and a slag layer 5 is provided between the casting bottom pad 4 and the lower ends of the guide electrode 2 and the granular flexible electrode 19.

[0027] The present invention is further described in detail below through embodiments and drawings.

[0028] Example 1

[0029] In this embodiment, the blades of the Francis turbine generator are electroslag cast, the material is ZG04Cr13Ni4Mo, the blades weigh 5 tons, the maximum thickness is 280mm, and the minimum thickness is 50mm. Figure 1 As shown, the design includes casting and processing allowances for the casting mold crystallizer 8, and the guide electrode 2 is arranged in the crystallizer cavity 1. The crystallizer cavity 1 is based on the shape of the casting itself, and the allowance is locally increased to obtain the conveying space of the arc-starting consumable electrode in the crystallizer. The guide electrode 2 is made of pipe material, and there is a safety gap of not less than 30 mm between the guide electrode 2 and the crystallizer cavity 1. Due to the distortion of the casting shape space, multiple guide electrodes are arranged in the crystallizer cavity. Figure 3 As shown, a granular metal 13 wrapped by a wrapping skin 14 is placed in the guide electrode 2 (the wrapping skin is made of the same material as the casting, and the granular metal is made of the same material as the casting). As the melting and casting process proceeds, the flexible electrode is continuously transported to the melting and casting area along the guide channel, and the melting and casting proceeds safely and smoothly. After melting and casting, the casting solidifies into a casting consistent with the crystallizer cavity.

[0030] Example 2

[0031] In this embodiment, the turbine generator blades are electroslag cast, the material is ZG04Cr13Ni5Mo, and the blade weight is 3 tons. Figure 2As shown, the design includes casting and processing allowances for the casting mold crystallizer, and the guide electrode 2 is arranged in the crystallizer cavity. The crystallizer cavity is based on the shape of the casting itself, and the allowance is locally increased to obtain the conveying space of the arc-starting consumable electrode in the crystallizer. The guide electrode 2 is made of pipe material, and there is a safety gap 10 of not less than 20 mm between the guide electrode 2 and the crystallizer cavity. Due to the distortion of the casting shape space, multiple guide electrodes are not in the cavity. The guide electrode 2 is placed in the wrapping skin wrapped granular flexible electrode 9 (the wrapping skin wrapped granular flexible electrode constitutes a capsule structure, and the material is the same as the casting). The adjacent capsules are tightly connected by the wrapping skin, and can be conveyed downward with the bending and deformation of the guide channel. As the melting and casting process proceeds, the flexible electrode is continuously conveyed to the melting and casting area along the guide channel, and the melting and casting is safe and stable. After melting and casting, the casting solidifies into a casting consistent with the crystallizer cavity.

[0032] Example 3

[0033] In this embodiment, the turbine generator blades are electroslag cast, the material is ZG04Cr13Ni4Mo, and the blade weight is 7 tons. Figure 1 As shown in the figure, the casting mold crystallizer including casting and machining allowances is designed, and the guide electrode 2 is arranged in the crystallizer cavity 1. The crystallizer cavity 1 is based on the shape of the casting itself, and the allowance is locally increased to obtain the conveying space of the arc-starting consumable electrode in the crystallizer cavity 1. The guide electrode 2 is made of pipe material, and there is a safety gap 10 of not less than 30 mm between it and the crystallizer cavity 1. Figure 4 As shown, due to the spatial distortion of the casting shape, multiple guide electrodes 2 are arranged in the crystallizer cavity 1, and a guide electrode magnetizing mechanism 16 is provided at the upper end of the guide electrode 2 to make the guide electrode 2 magnetic. At the same time, the guide electrode magnetizing mechanism 16 can maintain the guide electrode 2 always magnetic during the smelting process. The granular flexible electrode 19 is composed of particles of the same material as the casting. The granular flexible electrode 19 enters the guide channel of the guide electrode 2 from the flexible electrode entrance 7 and is adsorbed on the guide electrode 2 due to magnetism. A granular flexible electrode conveying drive device 17 for squeezing the granular electrode is provided at the flexible electrode entrance 7. As the smelting process proceeds, the granular flexible electrode 19 is squeezed and continuously conveyed to the smelting area along the guide channel of the guide electrode 2, and the smelting is carried out safely and smoothly. After smelting, the casting solidifies into a casting consistent with the crystallizer cavity.

[0034] In addition, the electroslag casting device can also be provided with an arc-starting consumable electrode, a guide electrode and a flexible electrode.

[0035] like Figure 5As shown, an electroslag melting device with an arc-striking consumable electrode, a guide electrode and a flexible electrode is provided, wherein a guide electrode 2 and an arc-striking consumable electrode 18 are provided in a crystallizer cavity 1, a safety gap 10 is maintained between the guide electrode 2 and the inner wall of the crystallizer cavity 1, a granular flexible electrode 19 is provided in a guide channel in the guide electrode 2, a casting bottom pad 4 is provided at the bottom opening of the crystallizer cavity 1, an arc-striking section 20 is provided at the lower end of the vertical arc-striking consumable electrode 18, and the lower part of the arc-striking section 20 corresponds to the casting bottom pad 4.

[0036] In the present invention, the material of the three-dimensional variable curved surface complex shape castings such as turbine generator blades can be carbon steel, low alloy steel or stainless steel, including but not limited to the materials described in the following standards (ASTM A743, ASTM A483, ASTMA148, EN 10283, GB / T 6967, GB / T 11352, JB / T 5000.6, JB / T 10384, JB / T 7349, JB / T6405), and the specific materials are exemplified as follows:

[0037] Carbon steel: ZG230-450, ZG270-500, ZG310-570, etc.;

[0038] Low alloy steel: ZG20SiMn, ZG25Mn18Cr4, etc.;

[0039] Stainless steel: ZG10Cr13, ZG06Cr13Ni4Mo, ZG04Cr13Ni5Mo, ZG06Cr16Ni5Mo, ZG00Cr13Ni4Mo, ZG00Cr16Ni5Mo, ASTMA743 CA6NM, GX4CrNi13-4, etc.

[0040] The implementation results show that the utility model solves the problem of complex-shaped castings, especially can be used for the manufacture of three-dimensional variable-curved complex-shaped castings such as hydro-generator blades by electroslag casting, broadens the application scope of electroslag casting technology, and increases the varieties of castings that can be produced by electroslag casting process.

Claims

1. An electroslag casting device for three-dimensional curved and complex shaped castings, characterized in that: The device includes: a guide electrode, a flexible electrode, a casting bottom pad, a slag layer, a casting bottom pad and a crystallizer insulating layer, and a crystallizer. The specific structure is as follows: a guide electrode is arranged in the crystallizer cavity of the crystallizer, the upper end of the guide channel in the guide electrode is the flexible electrode entrance, the flexible electrode is arranged in the guide channel in the guide electrode through the flexible electrode entrance, a casting bottom pad is arranged at the bottom opening of the crystallizer cavity, the lower part of the guide electrode and the flexible electrode corresponds to the casting bottom pad, and a slag layer is between the casting bottom pad and the lower ends of the guide electrode and the flexible electrode.

2. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 1, characterized in that: One or more straight guide electrodes or curved guide electrodes following the shape of the crystallizer cavity are arranged in the electroslag casting crystallizer cavity. The guide electrodes are fixed relative to the crystallizer and have guide channels inside.

3. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 1, characterized in that: Flexible electrodes are solid, wire-like or granular metals.

4. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 1, characterized in that: The flexible electrode is wrapped with a wrapping skin, or the guide electrode and the flexible electrode are magnetized to form a flexible electrode as a whole.

5. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 4, characterized in that: The wrapping skin is made of metal or non-metal. The metal skin is made of iron, steel or aluminum, or a metal material that has some or all of the same elements as the casting material. The non-metal skin is a non-metal woven fabric or other form that can achieve a wrapping effect.

6. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 1, characterized in that: A granular metal feeding hopper is provided at the entrance of the flexible electrode, a guide electrode magnetizing mechanism is provided between the bottom of the granular metal feeding hopper and the flexible electrode entrance, the top of the granular metal feeding hopper corresponds to the granular flexible electrode conveying drive device, and the granular flexible electrode is arranged in a guide channel in the guide electrode through the granular flexible electrode conveying drive device, the granular metal feeding hopper, the guide electrode magnetizing mechanism and the flexible electrode entrance.

7. The electroslag casting device for three-dimensional curved and complex-shaped castings according to claim 1, characterized in that: The electroslag casting device is also provided with an arc-striking consumable electrode. One or more guide electrodes are used as fixed consumable electrodes together with one or more movable arc-striking consumable electrodes. An arc-striking section is provided at the lower end of the vertical arc-striking consumable electrode, and the lower part of the arc-striking section corresponds to the bottom pad of the casting.

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