Composite crucible for smelting metal

Abstract

The utility model discloses a composite crucible for smelting metal, which comprises an inner wall layer and an outer wall layer wrapping the inner wall layer, a cavity capable of containing metal is defined by the inner wall layer, the inner wall layer is made of low-carbon steel, the outer wall layer is made of austenitic stainless steel, and the inner wall layer and the outer wall layer are connected to form a side wall structure of the composite crucible. A plurality of energy-saving rib plates protruding out of the surface of the side wall structure are arranged on the inner wall layer and / or the outer wall layer. The composite crucible is made of the composite steel plate of the austenitic stainless steel and the low-carbon steel, the oxidation resistance and the deformation resistance are remarkably improved, the energy-saving rib plates can increase the heating surface area of the crucible, energy is effectively saved, the deformation resistance of the composite crucible can be improved, and the service life of the composite crucible is prolonged.

Description

Technical Field

[0001] The utility model relates to a composite crucible for smelting metals and belongs to the technical field of light alloy casting. Background Art

[0002] There are two main types of traditional crucibles for melting magnesium alloys: one is made of low carbon steel, such as Figure 1 As shown in the figure, the melting temperature of magnesium alloy is 800℃, and the temperature of the furnace reaches 900℃. Low carbon steel is particularly easy to oxidize under high temperature conditions. The oxide scale will fall off after oxidation, and the wall thickness of the crucible will become thinner. The crucible will also deform under repeated high temperature. Therefore, the service life of the crucible of this material is only 20 furnaces. The other is made of bimetallic composite plate, such as Figure 2 As shown, the inner wall of this crucible is made of low-carbon steel and the outer wall is made of stainless steel plate. Therefore, the outer wall of the crucible has strong resistance to high-temperature oxidation and deformation resistance than the crucible made of low-carbon steel alone. The service life can reach 50 furnaces.

[0003] However, the common disadvantage of these two crucibles is that the heating speed is relatively slow and the heating efficiency is low. It takes 5 hours to completely melt 300Kg of magnesium alloy in a cold furnace, and it takes 3 hours to melt continuously in a hot furnace. This causes the magnesium alloy melt to be exposed to the air for a long time, increasing the probability of magnesium alloy oxidation and easily generating oxidation inclusion defects. From the perspective of the number of furnaces used, the life of the crucible is not very high. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model aims to provide a composite crucible for smelting metals.

[0005] In order to achieve the above-mentioned utility model purpose, the technical solution adopted by the utility model includes:

[0006] The utility model provides a composite crucible for smelting metal, comprising an inner wall layer and an outer wall layer wrapping the inner wall layer, the inner wall layer enclosing a chamber capable of accommodating metal, the inner wall layer being made of low carbon steel, the outer wall layer being made of austenitic stainless steel, the inner wall layer and the outer wall layer being connected to form a side wall structure of the composite crucible, and a plurality of energy-saving ribs protruding from the surface of the side wall structure are arranged on the inner wall layer and / or the outer wall layer.

[0007] Preferably, the inner wall layer and the outer wall layer are connected by explosion welding.

[0008] Preferably, the ratio between the thickness of the inner wall layer and the thickness of the outer wall layer is 1:2.5-3.

[0009] Preferably, the side wall structure comprises a main body and a bottom which are arranged in sequence, and the ratio between the wall thickness of the main body and the wall thickness of the bottom is 1:1.1-1.5.

[0010] Preferably, the main body is a hollow cylindrical structure, the bottom is a hollow hemispherical structure, the bottom closes one end of the main body, and the hollow parts of the main body and the bottom form the chamber.

[0011] Preferably, the thickness of the main body and the bottom of the side wall structure satisfies the following formula:

[0012] δ 底 =1.2δ

[0013] Wherein, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber, and the value range of V is 50-600Kg.

[0014] Alternatively, the thickness of the main body and the bottom of the side wall structure satisfies the following formula:

[0015] δ 底 =1.3δ

[0016] Wherein, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber, and the value range of V is 600-2000Kg.

[0017] Preferably, a plurality of the energy-saving ribs are arranged on the inner wall layer, and the plurality of the energy-saving ribs are evenly distributed along the circumference of the chamber.

[0018] Preferably, a plurality of the energy-saving ribs are distributed on the inner wall layer at the bottom.

[0019] Preferably, a plurality of the energy-saving ribs are arranged on the outer wall layer, and the plurality of the energy-saving ribs are evenly distributed along the circumference of the chamber.

[0020] Preferably, a plurality of the energy-saving ribs are arranged on the outer wall layer at positions on the main body and the bottom.

[0021] Preferably, the multiple energy-saving ribs are divided into a first group and a second group, the first group and the second group both include multiple energy-saving ribs, the first group is arranged on the inner wall layer, and the multiple energy-saving ribs of the first group are evenly distributed along the circumference of the chamber, and the second group is arranged on the outer wall layer, and the multiple energy-saving ribs of the second group are evenly distributed along the circumference of the chamber.

[0022] Preferably, a flange is provided at one end of the main body away from the bottom along the circumference of the shaft itself.

[0023] Preferably, the angle between the extension direction of the energy-saving rib protruding from the side wall structure and the tangent direction of the inner wall layer at the connection is 90°, or the angle between the extension direction of the energy-saving rib protruding from the side wall structure and the tangent direction of the inner wall layer at the connection is 45°60°.

[0024] Preferably, the thickness of the energy-saving rib plate is half the thickness of the side wall structure.

[0025] Preferably, the energy-saving rib plate protrudes from the surface of the side wall structure by a vertical height of 50-60 mm.

[0026] Preferably, the energy-saving rib plate is an austenitic stainless steel component.

[0027] Compared with the prior art, the advantages of the utility model include:

[0028] (1) The utility model is made of a composite steel plate of austenitic stainless steel and low carbon steel, and its oxidation resistance and deformation resistance are significantly improved.

[0029] (2) The energy-saving ribs designed in the utility model can increase the heating surface area of ​​the crucible, effectively saving energy; secondly, the energy-saving ribs can improve the deformation resistance of the composite crucible and increase the service life of the composite crucible.

[0030] (3) The utility model provides a calculation formula for the wall thickness of crucibles of different capacities, a proportional relationship between the thickness of the inner and outer walls of the crucible, and a proportional relationship between the thickness of the bottom of the crucible and the wall thickness of the crucible body, which is convenient for designers to design crucibles. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the cross-sectional structure of an existing low-carbon steel crucible;

[0032] Figure 2 It is a schematic diagram of the cross-sectional structure of an existing bimetallic composite plate crucible;

[0033] Figure 3 It is a schematic diagram of the cross-sectional structure of the composite crucible of the utility model;

[0034] Figure 4 yes Figure 3 Middle A direction view;

[0035] Figure 5 yes Figure 3 View from the middle B direction.

[0036] Description of reference numerals:

[0037] 110, inner wall layer; 120, outer wall layer; 130, chamber; 200, energy-saving rib plate; 310, flange. DETAILED DESCRIPTION

[0038] In view of the deficiencies in the prior art, the author of the present utility model has proposed the technical solution of the present utility model after long-term research and extensive practice.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0040] In addition, in the description of the present invention, it should be understood that the terms "upper", "lower", "inside", "outside", "horizontal", "vertical", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0041] In the description of this specification, the description with reference to the terms "one embodiment", "an embodiment", "the embodiment", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0042] The technical solution, its implementation process and principle will be further explained below in conjunction with the accompanying drawings.

[0043] See also Figure 3-Figure 5 The utility model provides a composite crucible for smelting metal, which includes an inner wall layer 110 and an outer wall layer 120 wrapping the inner wall layer 110, the inner wall layer 110 surrounds a chamber 130 for accommodating metal, the inner wall layer 110 is low carbon steel, the outer wall layer 120 is austenitic stainless steel, the inner wall layer 110 and the outer wall layer 120 are connected to form a side wall structure of the composite crucible, and a plurality of energy-saving ribs 200 protruding from the surface of the side wall structure are provided on the inner wall layer 110 and / or the outer wall layer 120.

[0044] In this embodiment, the composite crucible has a double-layer structure including an inner wall layer 110 located on the inner side and an outer wall layer 120 located on the outer side. The inner wall layer 110 and the outer wall layer 120 are connected and bonded together to form a side wall structure of the composite crucible, wherein the inner wall layer 110 encloses a chamber 130 for accommodating metal to be smelted. In this embodiment, the metal to be smelted is a magnesium alloy, and the outer wall layer 120 is wrapped around the outer side of the inner wall layer 110. The material of the inner wall layer 110 is low carbon steel, and the material of the outer wall layer 120 is austenitic stainless steel.

[0045] Compared with magnesium alloy, magnesium has a very low effect of corroding iron in the molten state, which is much lower than that of aluminum alloy. Therefore, an iron crucible can be used to melt magnesium alloy. From the perspective of material properties, the carbon content of low-carbon steel is less than 0.20%. The content of impurities copper and nickel in low-carbon steel is low (because copper and nickel will seriously reduce the corrosion resistance of magnesium alloy), and their content should be below 0.10%. Therefore, a crucible made of low-carbon steel is more suitable for melting magnesium alloy. In addition, the maximum use temperature of the crucible for melting magnesium alloy is about 900°C. When used for a long time, since low-carbon steel will expand at high temperature, the crucible will cool down quickly after pouring. The deformation caused by high temperature will not be able to recover in time. Finally, the deformation of the crucible is maintained, causing macroscopic deformation of the crucible. In order to reduce the deformation of the crucible at high temperature, a composite plate with an outer wall layer 120 of austenitic stainless steel and an inner wall layer 110 of low-carbon steel is used to make a crucible for melting magnesium alloy. Since the austenitic stainless steel of the outer wall layer 120 has strong oxidation resistance, the anti-deformation ability of the crucible is enhanced. The inner wall layer 110 may be made of any one of low carbon steels such as Q215, Q235, Q345, etc., and the outer wall layer 120 may be made of any one of austenitic stainless steels such as 316, 316L, 304, etc.

[0046] In addition, a plurality of energy-saving ribs 200 are connected to the side wall structure of the composite crucible, and the energy-saving ribs 200 protrude from the surface of the side wall structure. On the one hand, the provision of a plurality of energy-saving ribs can increase the heating surface area of ​​the composite crucible, thereby improving the melting efficiency and effectively saving energy; on the other hand, a plurality of energy-saving ribs 200 are provided on the side wall structure of the composite crucible, thereby improving the overall structural rigidity of the composite crucible, enhancing its deformation resistance, reducing deformation during use, and thereby increasing the service life of the composite crucible. At the same time, by providing the energy-saving ribs 200, while ensuring the structural strength of the composite crucible, the side wall structure can also be appropriately thinned, thereby reducing the use of side wall structure materials and improving material utilization.

[0047] Specifically, the inner wall layer 110 and the outer wall layer 120 are connected by explosion welding. The specific process of explosion welding is to produce metallurgical bonding between the low carbon steel plate and the austenitic stainless steel plate through explosive explosion to form a whole. This method makes the expansion coefficients of the above two steel plates basically consistent, so that the deformation of the two steel plates remains consistent. In addition, the explosion welding makes the composite steel plate fast in heat transfer and small in heat loss. When the traditional extruded bimetallic composite plate is used at high temperature for a long time, a gap will be generated between the two steel plates, which affects the heat transfer. In addition, due to the different expansion coefficients of the two steel plates, greater stress will be generated, causing the gap to further expand and deteriorate the performance of the crucible. In addition, after explosion welding, it is necessary to pass X-ray detection to check whether the defects meet the standard requirements. There should be no unwelded positions on the steel plate after explosion welding.

[0048] The utility model also provides a method for preparing a composite crucible for smelting metal, which comprises the following steps:

[0049] Providing a low carbon steel plate-like structure and an austenitic stainless steel plate-like structure In this step, a low carbon steel plate and an austenitic stainless steel plate are provided.

[0050] The low carbon steel plate structure and the austenitic stainless steel plate structure are connected by explosion welding to form a composite steel plate. In this step, the low carbon steel plate and the austenitic stainless steel plate are integrated into a whole composite steel plate by explosion welding.

[0051] Connect multiple energy-saving ribs 200 on the composite steel plate. In this step, a corresponding number of energy-saving ribs 200 are connected at corresponding positions as required.

[0052] The composite steel plate is rolled, stamped, and welded into a desired shape, the low carbon steel plate-like structure forms the inner wall layer 110, the austenitic stainless steel plate-like structure forms the outer wall layer 120, and the composite steel plate forms the side wall structure. Specifically, a portion of the composite steel plate is rolled into a cylindrical structure by a plate rolling machine, and then the cylindrical structure is welded end to end to form a main body, and the remaining composite steel plate is stamped by a stamping device to form the bottom of the hemispherical structure.

[0053] When welding the outer wall layer 120, the welding wire used is made of the same material as the outer wall layer 120, and when welding the inner wall layer 110, the welding wire used is made of the same material as the inner wall layer 110. The welding wire is made of the same material as the inner and outer walls, which can ensure the strength and quality of the welding seam and prevent contamination of the alloy liquid.

[0054] Specifically, the ratio between the thickness of the inner wall layer 110 and the thickness of the outer wall layer 120 is 1:2.5-3. This thickness ratio can meet the use requirements and can also effectively reduce the cost.

[0055] In the specific structure of the sidewall structure, the sidewall structure includes a main body and a bottom arranged in sequence, wherein the main body is a hollow cylindrical structure, the bottom is a hollow hemispherical structure, the bottom closes one end of the main body, and the hollow parts of the main body and the bottom form a chamber 130, and the ratio between the wall thickness of the main body and the wall thickness of the bottom is 1:1.1-1.5.

[0056] In this embodiment, the main body and the bottom are an integral structure, which is formed by integrally molding the side wall structure, wherein in the vertical direction, the main body is located on the upper side of the bottom, a part of the side wall structure is subjected to a molding process to be molded into a hemispherical hollow structure to form the bottom, and then the remaining part of the side wall structure is subjected to a molding process to be molded into a cylindrical hollow structure surrounding the bottom to form the main body, wherein the hollow structure of the main body and the hollow structure of the bottom are coaxially arranged and form a chamber 130 for containing the magnesium alloy. In addition, the ratio between the wall thickness of the main body and the wall thickness of the bottom is 1:1.1-1.5, and the wall thickness of the bottom is thicker than that of the main body, so that when receiving the molten magnesium alloy, the bearing capacity of the bottom can be effectively improved.

[0057] In the specific structure of the energy-saving ribs 200, in the first embodiment, a plurality of energy-saving ribs 200 are arranged on the inner wall layer 110, and the plurality of energy-saving ribs 200 are evenly distributed along the circumference of the chamber 130; specifically, a plurality of energy-saving ribs 200 are distributed at the bottom of the inner wall layer 110; specifically, at least 6 energy-saving ribs 200 are provided. In this embodiment, a plurality of energy-saving ribs 200 are arranged on the inner wall layer 110 of the composite crucible, and the energy-saving ribs 200 are strip structures, which extend along the length direction of the chamber 130, one side of the energy-saving ribs 200 is in contact with the inner wall layer 110, and the energy-saving ribs 200 protrude along the surface of the inner wall layer 110 toward the chamber 130, wherein this embodiment is provided with 6 energy-saving ribs 200, and the 6 energy-saving ribs 200 are arranged at the bottom of the inner wall layer 110, and a plurality of energy-saving ribs 200 are evenly spaced along the circumference of the chamber 130. Since the magnesium alloy will accumulate at the bottom when it is melted, the energy-saving ribs 200 are arranged at the bottom, so as to increase the contact area between the energy-saving ribs 200 and the magnesium alloy, and further improve the melting efficiency. In addition, the energy-saving ribs 200 are arranged at the bottom to improve the structural strength of the bottom, thereby reducing the high-temperature deformation of the bottom of the crucible.

[0058] In the second embodiment of the energy-saving ribs 200, a plurality of energy-saving ribs 200 are arranged on the outer wall layer 120, and the plurality of energy-saving ribs 200 are evenly distributed along the circumference of the chamber 130; specifically, a plurality of energy-saving ribs 200 are arranged on the outer wall layer 120 at the main body and the bottom; specifically, at least 15 energy-saving ribs 200 are provided. In this embodiment, a plurality of energy-saving ribs 200 are arranged on the outer wall layer 120. Specifically, 15 energy-saving ribs 200 are arranged on the outer wall layer 120. The 15 energy-saving ribs 200 are evenly spaced along the circumference of the outer wall layer 120. The energy-saving ribs 200 are strip-shaped structures, extending along the length direction of the chamber 130, and the energy-saving ribs 200 protrude along the outer wall layer 120 in a direction away from the chamber 130. The energy-saving ribs 200 are formed on the outer wall layer 120 at a portion of the main body and at the bottom. Since the heat radiation at the bottom side of the bottom is small, the energy-saving ribs 200 are not covered at this position, which can further save costs. In this embodiment, the energy-saving ribs 200 are arranged on the outer wall layer 120 to improve the structural strength of the outer wall layer 120, thereby increasing the supporting effect of the outer wall layer 120 on the inner wall layer 110 and reducing the high-temperature deformation of the inner wall layer 110.

[0059] In the third embodiment of the energy-saving ribs 200, the multiple energy-saving ribs 200 are divided into a first group and a second group, both of which include multiple energy-saving ribs 200. The first group is arranged on the inner wall layer 110, and the multiple energy-saving ribs 200 of the first group are evenly distributed along the circumference of the chamber 130. The second group is arranged on the outer wall layer 120, and the multiple energy-saving ribs 200 of the second group are evenly distributed along the circumference of the chamber 130. Specifically, the energy-saving ribs 200 of the first group are provided with at least 6, and the energy-saving ribs 200 of the second group are provided with at least 15. In this embodiment, multiple energy-saving ribs 200 are provided on both the outer wall layer 120 and the inner wall layer 110.

[0060] In addition, the angle between the extending direction of the energy-saving rib plate 200 protruding from the side wall structure and the tangent direction of the inner wall layer 110 at the connection point is 90°. In another embodiment, the angle between the extending direction of the energy-saving rib plate 200 protruding from the side wall structure and the tangent direction of the inner wall layer 110 at the connection point is 45°-60°. More specifically, the thickness of the energy-saving rib plate 200 is half of the thickness of the side wall structure; the vertical height of the energy-saving rib plate 200 protruding from the surface of the side wall structure is 50-60mm. The vertical height of the energy-saving rib plate 200 is affected by the width of the flange 310, which is generally half of the width of the flange 310 from the outer wall of the composite crucible, otherwise it affects the entry of the composite crucible into the melting furnace. When the angle between the extending direction of the energy-saving rib plate 200 protruding from the side wall structure and the tangent direction of the inner wall layer 110 at the connection point is 90°, it is convenient for welding and conducive to heat absorption. When the furnace size is limited, an angle other than 90° is used, that is, 45°-60° is selected. In addition, the energy-saving rib plate 200 is made of austenitic stainless steel, so that the energy-saving rib plate 200 has good high-temperature oxidation resistance, further improving its supporting effect on the side wall structure.

[0061] Specifically, in the selection of the thickness of the main body and the bottom of the side wall structure, it is calculated according to the mass of the metal that the chamber 130 can accommodate. When the capacity of the chamber 130 is 50-600Kg, the thickness of the main body and the bottom of the side wall structure meets the following requirements:

[0062] δ 底 =1.2δ

[0063] Where, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber 130, and the value range of V is 50-600;

[0064] In addition, when the capacity of the chamber 130 is 600-2000 kg, the thickness of the main body and the bottom of the side wall structure meets the following requirements:

[0065] δ 底 =1.3δ

[0066] Where, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber 130, and the value range of V is 600-2000Kg.

[0067] In addition, a flange 310 is provided along the circumference of the shaft at one end of the main body away from the bottom; specifically, the flange 310 is made of one or a combination of 20# steel and 45# steel. The flange 310 is provided at one end of the main body away from the bottom, so that the composite crucible can be easily taken and the composite crucible can be limited in the vertical direction.

[0068] The technical scheme of the utility model is further described in detail below in conjunction with several preferred embodiments and drawings. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the utility model. The test methods in the following embodiments that do not specify specific conditions are usually based on conventional conditions.

[0069] Implementation Example 1

[0070] 50Kg-600Kg (excluding 600Kg) composite crucible:

[0071] The wall thickness calculation formula of the composite crucible is:

[0072] δ 底 =1.2δ

[0073] δ represents the wall thickness of the main body (mm). The numbers after the decimal point are not rounded off but are rounded up.

[0074] δ 底 Indicates the wall thickness of the bottom (mm).

[0075] V represents the capacity (Kg) of the chamber 130 , and the value range of V is 50-600.

[0076] The angle between the extension direction of the protruding side wall structure of the energy-saving rib plate 200 and the tangent direction of the inner wall layer 110 at the connection point is 90°.

[0077] Implementation Example 2

[0078] 600Kg-2000Kg crucible:

[0079] The formula for calculating the crucible wall thickness is:

[0080] δ 底 =1.3δ

[0081] δ represents the wall thickness of the main body (mm). The numbers after the decimal point are not rounded off but are rounded up.

[0082] δ 底 Indicates the wall thickness of the bottom (mm).

[0083] V represents the capacity (Kg) of the chamber 130 , and the value range of V is 600-2000.

[0084] The angle between the extension direction of the energy-saving rib plate 200 protruding from the side wall structure and the tangent direction of the inner wall layer 110 at the connection point is 60°. At the same time, the length of the energy-saving rib plate 200 is extended to keep the vertical height of the energy-saving rib protruding from the crucible wall unchanged, so as to further increase the surface area of ​​the energy-saving plate.

[0085] Implementation Example 3

[0086] 3000Kg crucible: The wall thickness of the main body is 50mm, and the wall thickness of the bottom is 60mm. The angle between the extension direction of the protruding side wall structure of the energy-saving rib plate 200 and the tangent direction of the inner wall layer 110 at the connection point is 60°. At the same time, the length of the energy-saving rib plate 200 is extended, and the vertical height of the protruding crucible wall of the energy-saving rib is kept unchanged to further increase the surface area of ​​the energy-saving plate.

[0087] The energy-saving ribs 200 of the crucible of the utility model have two advantages (taking a 1000Kg crucible as a comparison object): first, the heating surface area of ​​the crucible is increased by more than 40%, which saves more than 30% energy compared with a traditional crucible; second, under the action of the energy-saving ribs 200, the deformation resistance of the crucible of the utility model is significantly improved compared with a traditional crucible, so the service life of the crucible of the utility model is increased by more than 30% compared with a traditional crucible.

[0088] Finally, it should be noted that the above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above examples, and there are many variations. All variations that can be directly derived or associated with the content disclosed by a person skilled in the art should be considered as the protection scope of the present invention.

[0089] It should be understood that the above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any equivalent changes or modifications made according to the spirit of the utility model should be included in the protection scope of the utility model.

Claims

1. A composite crucible for smelting metal, characterized in that: The composite crucible comprises: an inner wall layer and an outer wall layer wrapping the inner wall layer, the inner wall layer enclosing a chamber capable of accommodating metal, the inner wall layer being made of low carbon steel, the outer wall layer being made of austenitic stainless steel, the inner wall layer and the outer wall layer being connected to form a side wall structure of the composite crucible, and a plurality of energy-saving ribs protruding from the surface of the side wall structure are provided on the inner wall layer and / or the outer wall layer.

2. A composite crucible for smelting metal according to claim 1, characterized in that: The inner wall layer and the outer wall layer are connected by explosion welding.

3. A composite crucible for smelting metal according to claim 2, characterized in that: The ratio between the thickness of the inner wall layer and the thickness of the outer wall layer is 1:2.5-3.

4. The composite crucible for smelting metal according to claim 1, characterized in that: The side wall structure comprises a main body and a bottom which are arranged in sequence, and the ratio between the wall thickness of the main body and the wall thickness of the bottom is 1:1.1-1.5; And / or, the main body is a hollow cylindrical structure, the bottom is a hollow hemispherical structure, the bottom closes one end of the main body, and the hollow parts of the main body and the bottom form the chamber.

5. A composite crucible for smelting metal according to claim 4, characterized in that: The thickness of the main body and the bottom of the side wall structure satisfies the following formula: d 底 =1.2d Wherein, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber, and the value range of V is 50-600Kg; Alternatively, the thickness of the main body and the bottom of the side wall structure satisfies the following formula: d 底 =1.3d Wherein, δ is the wall thickness of the main body (mm), and the decimal point is rounded up; δ 底 is the wall thickness of the bottom (mm); V is the capacity of the chamber, and the value range of V is 600-2000Kg.

6. The composite crucible for smelting metal according to claim 4, characterized in that: A plurality of the energy-saving ribs are arranged on the inner wall layer, and the plurality of the energy-saving ribs are evenly distributed along the circumference of the chamber; And / or, a plurality of the energy-saving ribs are distributed on the inner wall layer at the bottom.

7. The composite crucible for smelting metal according to claim 4, characterized in that: A plurality of the energy-saving ribs are arranged on the outer wall layer, and the plurality of the energy-saving ribs are evenly distributed along the circumference of the chamber; And / or, a plurality of energy-saving ribs are arranged on the outer wall layer at positions on the main body and the bottom.

8. The composite crucible for smelting metal according to claim 4, characterized in that: The multiple energy-saving ribs are divided into a first group and a second group, the first group and the second group both include multiple energy-saving ribs, the first group is arranged on the inner wall layer, and the multiple energy-saving ribs of the first group are evenly distributed along the circumference of the chamber, and the second group is arranged on the outer wall layer, and the multiple energy-saving ribs of the second group are evenly distributed along the circumference of the chamber.

9. The composite crucible for smelting metal according to claim 4, characterized in that: One end of the main body away from the bottom is provided with a flange along the circumference of the shaft itself.

10. A composite crucible for smelting metal according to any one of claims 1 to 9, characterized in that: The angle between the extending direction of the energy-saving rib protruding from the side wall structure and the tangent direction of the inner wall layer at the connection point is 90°, or the angle between the extending direction of the energy-saving rib protruding from the side wall structure and the tangent direction of the inner wall layer at the connection point is 45°-60°; and / or, the thickness of the energy-saving rib plate is half the thickness of the side wall structure; And / or, the vertical height of the energy-saving rib plate protruding from the surface of the side wall structure is 50-60 mm; And / or, the energy-saving rib plate is an austenitic stainless steel component.

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