A riser assembly and low pressure casting apparatus

Abstract

The utility model relates to a kind of liquid lifting components and low-pressure casting equipment, and liquid lifting component includes heat-resistant stainless steel matrix and anti-sticking coating;Anti-sticking coating includes transition layer and surface layer, transition layer is formed on the inner wall of heat-resistant stainless steel matrix, surface layer is formed on the inner surface of transition layer, transition layer is nickel-based alloy layer, and surface layer is anti-sticking composite ceramic coating.Heat-resistant stainless steel matrix has strong pressure resistance, and is resistant to thermal fatigue, can maintain structural strength under high-temperature casting environment, is not prone to deformation, thereby ensuring the mold connection sealing property of low-pressure casting equipment;Anti-sticking coating can maximize inhibit the generation and adhesion of alumina fouling layer, reduce shutdown maintenance frequency, ensure low-pressure casting production continuity and casting quality.

Description

Technical Field

[0001] This utility model belongs to the technical field of low-pressure casting equipment, specifically relating to a liquid lifting component with anti-sticking function and a low-pressure casting equipment including the liquid lifting component. Background Technology

[0002] Low-pressure casting is a casting method in which molten alloy is forced into a mold cavity from bottom to top under pressure, thereby solidifying to obtain a casting. The principle of low-pressure casting is as follows: dry compressed air is first introduced into the crucible of a sealed holding furnace. The pressure acting on the molten metal heats the molten metal to a suitable filling temperature, and the mold is also heated to a suitable temperature. A pressure difference is created between the cavity and the crucible, and the molten metal fills the mold from bottom to top under pressure. After the casting is completed, the pressure on the liquid surface is released, and the molten metal that has not solidified in the riser pipe and the mold cavity flows back to the crucible by gravity. Then the mold is opened and the casting is removed.

[0003] In low-pressure casting of aluminum alloys, the liquid rising component (liquid rising tank, liquid rising pipe) is the key channel connecting the holding furnace and the mold. The liquid aluminum flows into the mold cavity or back to the crucible of the holding furnace through the liquid rising component.

[0004] The existing liquid lifting components mainly have the following problems: (1) Adhesion and oxidation scale of aluminum liquid: aluminum liquid reacts readily with oxygen in the air to form a hard Al2O3 (aluminum oxide) scale layer, which adheres to the inner wall of the riser tank and the inner wall of the riser pipe; (2) Reduce effective diameter: Scale will continue to accumulate, making the inner diameter of the riser pipe smaller, affecting the stability of the aluminum liquid flow and the filling speed, and ultimately leading to casting defects; (3) Peeling produces impurities: When the scale layer is unstable, it will peel off and enter the mold cavity with the aluminum liquid, causing slag inclusions in the casting and making it a waste product; (4) Difficult and dangerous to clean: Cleaning the hard Al2O3 (alumina) scale layer is very laborious, requiring knocking and drilling, which not only damages the equipment but also poses safety risks.

[0005] Therefore, it is urgent to improve the existing low-pressure casting liquid lifting components so that they can suppress the formation and adhesion of Al2O3 scale layer to the greatest extent, improve the service life of the liquid lifting components, reduce the frequency of downtime maintenance, and ensure production continuity and casting quality. Summary of the Invention

[0006] This invention provides a liquid lifting component and a low-pressure casting equipment, which can solve the problem that the inner wall of the liquid lifting component in the existing low-pressure casting equipment is prone to forming an alumina scale layer, which is difficult to clean and affects the continuity of production and casting quality.

[0007] To achieve the above-mentioned technical effects, the technical solution adopted by the liquid lifting component proposed in this utility model is as follows: A liquid lifting component includes a heat-resistant stainless steel substrate and an anti-stick coating; the anti-stick coating includes a transition layer and a surface layer, the transition layer is formed on the inner wall of the heat-resistant stainless steel substrate, the surface layer is formed on the inner surface of the transition layer, the transition layer is a nickel-based alloy layer, and the surface layer is an anti-stick composite ceramic coating.

[0008] The anti-stick composite ceramic coating is a ZrO2 / Y2O composite ceramic coating, or a ZrO2 / Al2O3 composite ceramic coating, or a ZrO2 / Y2O / Al2O3 composite ceramic coating.

[0009] The transition layer is an APS plasma spray coating, and the surface layer is an APS plasma spray coating.

[0010] The thickness of the transition layer is 20-200 μm, and the thickness of the surface layer is 200-600 μm.

[0011] An inorganic sealing agent layer is also formed on the inner surface of the surface layer.

[0012] A sprayed layer is formed on the inner wall of the heat-resistant stainless steel substrate, the sprayed layer being located between the heat-resistant stainless steel substrate and the transition layer, and its roughness is Ra3-6.

[0013] The liquid lifting components are a liquid lifting tank and / or a liquid lifting pipe.

[0014] This utility model also proposes a low-pressure casting equipment, including a frame, a mold, a holding furnace and a liquid lifting component, characterized in that the liquid lifting component is the aforementioned liquid lifting component.

[0015] Compared with the prior art, the present invention has the following advantages and positive effects: 1. The liquid lifting component of this utility model includes a heat-resistant stainless steel substrate, that is, the substrate of the liquid lifting component is made of heat-resistant stainless steel, which has strong pressure resistance and is resistant to thermal fatigue. It can maintain structural strength in high-temperature casting environment and is not easy to deform, thereby ensuring the sealing of the mold connection with low-pressure casting equipment. At the same time, the heat-resistant stainless steel substrate is resistant to high-temperature oxidation, is not easy to oxidize and rust in high-temperature casting environment, and has good welding performance, which is conducive to improving service life. 2. The liquid-lifting component of this utility model includes an anti-stick coating, which comprises a transition layer and a surface layer. The transition layer is formed on the inner wall of the heat-resistant stainless steel substrate, and the surface layer is formed on the inner surface of the transition layer. This forms a multi-layer composite coating on the inner side of the liquid-lifting component substrate, creating a protective structure for the substrate. This isolates the inner surface of the substrate from the high-temperature casting environment, thus isolating some of the heat. The transition layer is a nickel-based alloy layer. Using a nickel-based alloy as the transition layer provides good thermal shock resistance, enabling it to withstand extreme high-temperature environments and rapid high-low temperature alternations during the casting process. It also maintains the connection stability between the substrate and the surface layer, preventing insufficient bonding strength that could lead to peeling or excessive porosity. The surface layer is an anti-sticking composite ceramic coating, which resists high-temperature aluminum corrosion, reduces alumina scaling on the surface of the liquid-lifting tank, and is non-wetting, making it difficult for aluminum to adhere. This maximizes the inhibition of alumina scaling formation and adhesion, reduces downtime for maintenance, and ensures continuous low-pressure casting production and casting quality. 3. The liquid lifting component of this utility model can be reused repeatedly. After a certain period of use, the surface coating can be repaired and it can be used again, which can reduce production costs to the greatest extent. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a three-dimensional structural diagram of the liquid-lifting component of this utility model; Figure 2 for Figure 1 Top view; Figure 3 for Figure 2 AA section view; Figure 4 for Figure 3 Enlarged view of part B.

[0018] Reference numerals: 10, liquid tank; 11, heat-resistant stainless steel substrate; 12, transition layer; 13, surface layer. Detailed Implementation

[0019] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0020] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0021] Reference Figures 1 to 4 In some embodiments of this application, a liquid lifting component, specifically a liquid lifting tank 10 of a low-pressure casting equipment, includes a heat-resistant stainless steel substrate 11 and an anti-stick coating; the outline shape of the heat-resistant stainless steel substrate 11 is the same as the outline shape of a liquid lifting tank in the prior art; the anti-stick coating includes a transition layer 12 and a surface layer 13, the transition layer 12 is formed on the inner wall of the heat-resistant stainless steel substrate 11 and covers the inner wall of the heat-resistant stainless steel substrate 11, and the surface layer 13 is formed on the inner surface of the transition layer 12 and covers the inner surface of the transition layer 12, the transition layer 12 is a nickel-based alloy layer, and the surface layer 13 is an anti-stick composite ceramic coating.

[0022] The liquid lifting component uses a heat-resistant stainless steel base of 11, which has strong pressure resistance and can prevent production accidents such as cracking and aluminum leakage caused by sudden pressure abnormalities during production. It is also resistant to thermal fatigue, and can maintain structural strength in high-temperature casting environments, making it less prone to deformation, thereby ensuring the sealing of the connection with the mold of the low-pressure casting equipment. At the same time, the heat-resistant stainless steel base of 11 is resistant to high-temperature oxidation, and is not easily oxidized and corroded in high-temperature casting environments (aluminum liquid temperature 700-750°C). It also has good welding performance, which helps to improve service life.

[0023] The heat-resistant stainless steel substrate 11 can be made of heat-resistant stainless steel 310S or other heat-resistant stainless steel, without specific restrictions.

[0024] An anti-stick coating is provided on the inner side of the heat-resistant stainless steel substrate 11. The anti-stick coating includes a transition layer 12 and a surface layer 13. The transition layer 12 is formed on the inner wall of the heat-resistant stainless steel substrate 11, and the surface layer 13 is formed on the inner surface of the transition layer 12. Thus, a multi-layer composite coating is formed on the inner side of the liquid tank substrate, forming a protective structure for the heat-resistant stainless steel substrate 11, so that the inner surface of the heat-resistant stainless steel substrate 11 can be isolated from the high-temperature casting environment and a portion of the heat can be isolated.

[0025] The transition layer 12 is a nickel-based alloy layer. This nickel-based alloy can connect with both the outer heat-resistant stainless steel substrate and the inner surface layer 13, serving as a transition layer. Using a nickel-based alloy as the transition layer provides good thermal shock resistance, enabling it to withstand extreme high-temperature environments and rapid temperature changes during casting. It also maintains the stability of the connection between the substrate and the surface layer, preventing insufficient bonding strength that could lead to peeling or excessive porosity.

[0026] The surface layer 13 is an anti-stick composite ceramic coating that can resist corrosion from high-temperature molten aluminum, reduce scale formation of alumina on the surface of the riser tank, and has non-wetting properties, making it difficult for molten aluminum to adhere. This maximizes the inhibition of the formation and adhesion of alumina scale, reduces the frequency of downtime maintenance, and ensures the continuity of low-pressure casting production and the quality of castings.

[0027] In some embodiments of this application, the anti-stick composite ceramic coating is a ZrO2 / Y2O composite ceramic coating, that is, a composite ceramic coating composed of ZrO2 and Y2O; or a ZrO2 / Al2O3 composite ceramic coating, that is, a composite ceramic coating composed of ZrO2 and Al2O3; or a ZrO2 / Y2O / Al2O3 composite ceramic coating, that is, a composite ceramic coating composed of ZrO2, Y2O, and Al2O3. The above-mentioned composite ceramic coatings have good adhesion and hardness, which makes the formed surface layer 13 have stronger bonding strength and wear resistance, and the surface is more stable.

[0028] In some embodiments of this application, the transition layer 12 and the surface layer 13 are both formed by APS plasma spraying, which forms a dense protective layer on the inner wall of the heat-resistant stainless steel substrate.

[0029] In some embodiments of this application, the thickness of the transition layer 12 is 20-200 μm, and the thickness of the top layer 13 is 200-600 μm. The porosity of the transition layer 12 and the top layer 13 is maintained in the range of 0.5-1.9%, resulting in small pores in the composite coating and forming a dense protection. Further, the porosity of the top layer 13 is preferably less than 1.5%, and the hardness value of the top layer 13 is 800-900 HV, further increasing the protective life of the final protective layer.

[0030] Furthermore, an inorganic sealing agent layer (not shown) is formed on the inner surface of the surface layer 13. The sealing agent provides further protection on the inner side of the surface layer and can protect and seal the surface voids of the surface layer 13, so that the porosity of the surface layer can be kept less than 1.5%.

[0031] In some embodiments of this application, the inner wall of the heat-resistant stainless steel substrate 11 is pre-treated to form a sprayed layer (not shown) with a roughness of Ra3-6, and then a transition layer is sprayed, with the sprayed layer located between the heat-resistant stainless steel substrate 11 and the transition layer 12. By increasing the roughness of the inner wall of the heat-resistant stainless steel substrate 11, microstructures with different tilt angles are formed on the surface, which increases the inner wall area of ​​the heat-resistant stainless steel substrate 11, thereby increasing the contact area between the heat-resistant stainless steel substrate 11 and the transition layer 12, and thus increasing the bonding strength between the two.

[0032] In some embodiments of this application, the liquid lifting component can also be a liquid lifting pipe, that is, the liquid lifting pipe is a composite structure of heat-resistant stainless steel substrate and anti-stick coating to achieve the anti-stick function.

[0033] In some embodiments of this application, the liquid lifting component is a combination structure of a liquid lifting tank and a liquid lifting pipe, with the upper outlet of the liquid lifting pipe sealed to the lower inlet of the liquid lifting tank. Both the liquid lifting tank and the liquid lifting pipe are composite structures with a heat-resistant stainless steel substrate and an anti-stick coating.

[0034] In some embodiments of this application, a low-pressure casting apparatus is also proposed, including a frame, a mold, a holding furnace, and a liquid lifting component.

[0035] The frame is equipped with a workbench for placing molds; a holding furnace is located below the workbench, and a crucible is placed inside the holding furnace to hold molten metal, such as molten aluminum.

[0036] The molten metal lifting component is installed on top of the holding furnace and is used to lift the molten metal in the furnace crucible into the mold cavity, or, after casting, to allow the molten metal in the mold cavity to flow back into the crucible by its own weight. The specific structure of the lifting component is described in some embodiments of this application and will not be repeated here.

[0037] The liquid lifting components of low-pressure casting equipment typically include a liquid lifting tank and a liquid lifting pipe. The upper outlet of the liquid lifting tank is sealed to the mold cavity, and the lower inlet is sealed to the upper outlet of the liquid lifting pipe. The lower inlet of the liquid lifting pipe is submerged in the molten metal in the crucible of the holding furnace.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A liquid lifting component, characterized in that: The liquid lifting component includes a heat-resistant stainless steel substrate and an anti-stick coating; the anti-stick coating includes a transition layer and a surface layer, the transition layer is formed on the inner wall of the heat-resistant stainless steel substrate, the surface layer is formed on the inner surface of the transition layer, the transition layer is a nickel-based alloy layer, and the surface layer is an anti-stick composite ceramic coating.

2. The liquid lifting component according to claim 1, characterized in that: The transition layer is an APS plasma spray coating, and the surface layer is an APS plasma spray coating.

3. The liquid lifting component according to claim 1, characterized in that: The thickness of the transition layer is 20-200 μm, and the thickness of the surface layer is 200-600 μm.

4. The liquid lifting component according to claim 3, characterized in that: An inorganic sealing agent layer is also formed on the inner surface of the surface layer.

5. The liquid lifting component according to claim 1, characterized in that: A sprayed layer is formed on the inner wall of the heat-resistant stainless steel substrate, the sprayed layer being located between the heat-resistant stainless steel substrate and the transition layer, and its roughness is Ra3-6.

6. The liquid lifting component according to claim 1, characterized in that: The liquid lifting components are a liquid lifting tank and / or a liquid lifting pipe.

7. A low-pressure casting equipment, comprising a frame, a mold, a holding furnace, and a liquid lifting component, characterized in that, The liquid lifting component is the liquid lifting component according to any one of claims 1 to 6.

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