Process for the production of a cast part with a plug-free vent

Abstract

The application provides a preparation process of a casting with a plugging-free exhaust plug, comprising the following steps: S1, designing the structure of the exhaust plug; S2, designing an exhaust plug wax film mold, and injecting wax into the designed mold to obtain an exhaust plug wax film; S3, designing a casting mold group; S4, immersing the casting mold group into a surface layer slurry, covering a layer of zirconia sand after slurry immersion, and then drying to obtain a mold group one; S5, immersing the mold group one into a back layer slurry, covering a layer of mullite sand after slurry immersion, and then drying to obtain a mold group two; S6, repeating step S5 at least five times to obtain a mold group three, and knocking off the exhaust port of the mold group three to obtain a mold group four; and S7, baking the mold group four, cleaning the mold shell of the mold group four by using compressed air, preheating to 1000-1150 DEG C, and then pouring to obtain a casting. The preparation process of the casting with the plugging-free exhaust plug simplifies the forming scheme of a traditional mold shell exhaust plug, simultaneously eliminates the process of plugging the exhaust plug by using a refractory material after baking, improves the work efficiency, and also eliminates the quality risk.

Description

Technical Field

[0001] This invention relates to the field of precision casting technology for aerospace, and in particular to a manufacturing process for castings with a plug-free vent plug. Background Technology

[0002] High-temperature alloy investment castings have wide applications in the aerospace field. These castings typically have thin walls and complex structures. During precision casting, conical vent plugs are often designed during the densification process to ensure rapid wax flow during dewaxing, reducing mold shell cracking. The vent plugs also ensure complete combustion of the mold shell during pre-baking. The conical vent plugs require grinding the opening during dewaxing, and after pre-baking, workers need to seal them with refractory material to prevent foreign matter from entering the mold cavity and causing slag inclusions, or causing molten steel to overflow during pouring. These operations cause inconvenience to workers and also introduce quality risks. Summary of the Invention

[0003] The purpose of this invention is to overcome and supplement the deficiencies in the existing technology, and to provide a manufacturing process for castings with a plug-free vent plug, which simplifies the operation of workers and enables the wax liquid to flow out quickly from the mold cavity during dewaxing, and the vent plug does not need to be blocked with refractory clay after firing.

[0004] The technical solution adopted in this invention is:

[0005] A manufacturing process for a casting with a plug-free vent plug, comprising the following steps:

[0006] S1. Design the structure of the exhaust plug, the exhaust plug includes a first exhaust section, a transition section and a second exhaust section, one end of the transition section is connected to the first exhaust section and the other end of the transition section is connected to the second exhaust section, and an exhaust port is provided at the end of the second exhaust section away from the transition section;

[0007] S2. Design the vent plug wax mold, and fill the designed mold with wax to obtain the vent plug wax mold;

[0008] S3. Design the casting module, which includes a casing and a horizontal runner located at the top of the casing. Venting plug wax molds are provided on both sides of the top of the horizontal runner.

[0009] S4. Immerse the casting module in the surface slurry, cover it with a layer of zirconia sand after immersion, and then dry it to obtain module one;

[0010] S5. Immerse the module one prepared in step S4 into the back layer slurry, cover it with a layer of mullite after slurry immersion, and then dry it to obtain module two.

[0011] S6. Repeat step S5 at least five times to obtain module three, and knock off the exhaust port of module three to obtain module four;

[0012] S7. After the baking of the mold, the mold shell of the mold four is cleaned by compressed air, and after preheating to 1000-1150℃, pouring is carried out to obtain the casting.

[0013] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the diameter of the exhaust port in step S1 is 6mm, the structure of the exhaust plug is L-shaped, the length of the first exhaust section is greater than that of the second exhaust section, and the first exhaust section is provided with a reinforcing rib at the end away from the transition section.

[0014] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the pressure of the wax injection in step S2 is 15-25Bar, the wax temperature is 51-61℃, the injection time is 15-25s, the holding time is 5-15s, and the injection flow is 75-85cc / s.

[0015] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the wax mold of the exhaust plug in step S2 includes a lower mold, an upper mold, a wax pressing channel and an exhaust plug cavity, two groups of exhaust plug assemblies are arranged in parallel in the lower mold, a wax pressing channel is arranged between the two groups of exhaust plug assemblies, each group of exhaust plug assemblies includes a plurality of exhaust plug cavities arranged at intervals, and an exhaust passage is arranged at one end of each exhaust plug cavity close to the side edge of the lower mold, and the upper end of the lower mold is provided with the upper mold.

[0016] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the surface layer slurry in step S4 includes silica sol and zirconia powder, the weight ratio of the silica sol and the zirconia powder is (2-2.5):(10-10.5), and the viscosity of the surface layer slurry is 45-55 S.

[0017] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the back layer slurry in step S5 includes silica sol and mullite powder, the mass ratio is 1:(2-2.5), and the viscosity of the back layer slurry is 15-20 S.

[0018] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the drying time in step S4 is 4-6h, and the drying temperature is 20-26℃; the drying time in step S5 is 8-12h, and the drying temperature is 20-26℃.

[0019] Preferably, the preparation process of the casting with the plugging-free exhaust plug, wherein: the baking temperature in step S7 is 900-1000℃, and the baking time is 1-3h.

[0020] Advantages of the present application:

[0021] (1) The preparation process of the casting with the plugging-free exhaust plug simplifies the forming scheme of the traditional mold shell exhaust plug, simultaneously eliminates the process of plugging the exhaust plug with refractory material after baking, improves the work efficiency, and also eliminates the quality risk. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of the exhaust plug of the present application.

[0023] Figure 2 It is a structural schematic diagram of the exhaust plug wax mold mold of the present application.

[0024] Figure 3 It is a structural schematic diagram of the casting mold group of the present application.

[0025] Figure 4 It is a structural schematic diagram of the fourth mold group of the present application. DETAILED DESCRIPTION

[0026] The present application will be further described below in combination with specific drawings and examples.

[0027] Example 1

[0028] A preparation process of a casting with a plugging-free exhaust plug, comprising the following steps:

[0029] S1. Design the structure of the exhaust plug, such as Figure 1 The exhaust plug comprises a first exhaust section 3, a transition section 5 and a second exhaust section 2, one end of the transition section 5 is connected to the first exhaust section 3, the other end of the transition section 5 is connected to the second exhaust section 2, an exhaust port 1 is arranged at the end of the second exhaust section 2 away from the transition section 5, the diameter of the exhaust port 1 is 6mm, the structure of the exhaust plug is L-shaped, the length of the first exhaust section 3 is greater than the length of the second exhaust section 2, and a reinforcing rib 4 is arranged at the end of the first exhaust section 3 away from the transition section 5;

[0030] S2. Design the exhaust plug wax mold mold, and obtain the exhaust plug wax mold 6 by injecting wax into the designed mold, the injection pressure is 15Bar, the wax temperature is 51℃, the injection time is 15s, the pressure maintaining time is 5s, and the injection flow rate is 75cc / s;

[0031] As shown in Figure 2 The exhaust plug wax mold mold comprises a lower mold 9, an upper mold 10, a wax injection channel 11 and an exhaust plug cavity 12, two groups of exhaust plug assemblies are arranged in parallel in the lower mold 9, the wax injection channel 11 is arranged between the two groups of exhaust plug assemblies, each group of exhaust plug assemblies comprises a plurality of exhaust plug cavities 12 arranged at intervals, an exhaust channel 13 is arranged at one end of each exhaust plug cavity 12 close to the side edge of the lower mold 9, and the upper end of the lower mold 9 is provided with the upper mold 10;

[0032] S3. Design the casting mold group, such as Figure 3The casting module comprises a box 7 and a cross runner 8 arranged at the upper end of the box 7, the cross runner 8 comprises two, the two cross runners 8 are arranged vertically, the top end of the two cross runners 8 is provided with a sprue cup 14, and the exhaust plug wax mold is bonded to the upper end of the two ends of the cross runner 8 to obtain the casting module;

[0033] S4. Immersing the casting module into the surface layer slurry, after immersion, covering a layer of zirconia sand, and then drying to obtain module one, the surface layer slurry comprises silica sol and zirconia powder, the weight ratio of the silica sol and the zirconia powder is 2:10, the viscosity of the surface layer slurry is 45 S, the drying time is 4h, and the drying temperature is 20℃;

[0034] S5. Immersing the module one prepared in step S4 into the back layer slurry, after immersion, covering a layer of mullite sand, and then drying to obtain module two, the back layer slurry comprises silica sol and mullite powder, the mass ratio is 1:2, the viscosity of the back layer slurry is 15 S, the drying time is 8h, and the drying temperature is 20℃;

[0035] S6. Repeating step S5 at least five times to obtain module three, knocking off the exhaust port 1 of the module three to obtain module four, and the structure of the module four is as shown in Figure 4 ;

[0036] S7. Firing the module four, the firing temperature is 900℃, the firing time is 3h, then directly cleaning the mold shell of the module four by using compressed air, preheating to 1000℃, and then pouring the metal liquid into the mold shell to obtain the casting.

[0037] Example 2

[0038] A preparation process of a casting with a plugging-free exhaust plug, comprising the following steps:

[0039] S1. Designing the structure of the exhaust plug, as shown in Figure 1 , the exhaust plug comprises a first exhaust section 3, a transition section 5 and a second exhaust section 2, one end of the transition section 5 is connected to the first exhaust section 3, the other end of the transition section 5 is connected to the second exhaust section 2, the exhaust port 1 is arranged at the end of the second exhaust section 2 away from the transition section 5, the diameter of the exhaust port 1 is 6mm, the structure of the exhaust plug is L-shaped, the length of the first exhaust section 3 is greater than the length of the second exhaust section 2, and the reinforcing rib 4 is arranged at the end of the first exhaust section 3 away from the transition section 5;

[0040] S2. Designing the exhaust plug wax mold, injecting wax into the designed mold to obtain the exhaust plug wax mold 6, the injection pressure is 20Bar, the wax temperature is 56℃, the injection time is 20s, the pressure maintaining time is 10s, and the injection flow rate is 80cc / s;

[0041] as shown in Figure 2The vent plug wax mold comprises a lower mold 9, an upper mold 10, a wax pressing channel 11 and a vent plug cavity 12, two groups of vent plug assemblies are arranged in parallel in the lower mold 9, the wax pressing channel 11 is arranged between the two groups of vent plug assemblies, each group of vent plug assemblies comprises a plurality of vent plug cavities 12 arranged at intervals, and a vent channel 13 is arranged at one end of each vent plug cavity 12 close to the side edge of the lower mold 9, and the upper end of the lower mold 9 is provided with the upper mold 10;

[0042] S3. Design a casting mold group, such as Figure 3 , the casting mold group comprises a machine case 7 and a cross runner 8 arranged at the upper end of the machine case 7, the cross runner 8 comprises two, the two cross runners 8 are arranged vertically, and the cross runner 8 at the vertical position is provided with a sprue cup 14 at the top end, and the vent plug wax mold is bonded at the upper end of the two ends of the cross runner 8 to obtain the casting mold group;

[0043] S4. Dip the casting mold group into the surface layer slurry, cover a layer of zirconia sand after dipping, and then dry to obtain a mold group one, the surface layer slurry comprises silica sol and zirconia powder, the weight ratio of the silica sol and the zirconia powder is 2.2:10.2, the viscosity of the surface layer slurry is 50S, the drying time is 5h, and the drying temperature is 22℃;

[0044] S5. Dip the mold group one prepared in step S4 into the back layer slurry, cover a layer of mullite sand after dipping, and then dry to obtain a mold group two, the back layer slurry comprises silica sol and mullite powder, the mass ratio is 1: (2-2.5), the viscosity of the back layer slurry is 18S, the drying time is 10h, and the drying temperature is 22℃;

[0045] S6. Repeat step S5 at least five times to obtain a mold group three, knock off the vent port 1 of the mold group three to obtain a mold group four, and the structure of the mold group four is as shown in Figure 4 ;

[0046] S7. Bake the mold group four, the baking temperature is 960℃, the baking time is 2h, then directly clean the mold shell of the mold group four with compressed air, preheat to 1100℃, then pour the metal liquid into the mold shell for pouring to obtain a casting.

[0047] Example 3

[0048] A preparation process of a casting with a plugging-free vent plug, comprising the following steps:

[0049] S1. Design the structure of the vent plug, such as Figure 1, the exhaust plug comprises a first exhaust section 3, a transition section 5 and a second exhaust section 2, one end of the transition section 5 is connected to the first exhaust section 3, the other end of the transition section 5 is connected to the second exhaust section 2, one end of the second exhaust section 2 away from the transition section 5 is provided with an exhaust port 1, the diameter of the exhaust port 1 is 6mm, the structure of the exhaust plug is L-shaped, the length of the first exhaust section 3 is greater than the length of the second exhaust section 2, and a reinforcing rib 4 is arranged at one end of the first exhaust section 3 away from the transition section 5;

[0050] S2. Design the exhaust plug wax mold, and obtain the exhaust plug wax mold 6 by injecting wax into the designed mold, the injection pressure is 25Bar, the wax temperature is 61℃, the injection time is 25s, the pressure maintaining time is 15s, and the injection flow rate is 85cc / s;

[0051] As shown in Figure 2 The exhaust plug wax mold comprises a lower mold 9, an upper mold 10, a wax injection channel 11 and an exhaust plug cavity 12, two groups of exhaust plug assemblies are arranged in parallel in the lower mold 9, the wax injection channel 11 is arranged between the two groups of exhaust plug assemblies, each group of exhaust plug assemblies comprises a plurality of exhaust plug cavities 12 arranged at intervals, and an exhaust channel 13 is arranged at one end of each exhaust plug cavity 12 close to the side edge of the lower mold 9, and the upper end of the lower mold 9 is provided with the upper mold 10;

[0052] S3. Design the casting mold group, as shown in Figure 3 The casting mold group comprises a machine case 7 and a cross runner 8 arranged at the upper end of the machine case 7, the cross runner 8 comprises two, the two cross runners 8 are arranged vertically, and the top end of the cross runner 8 arranged vertically is provided with a sprue cup 14, and the exhaust plug wax mold is bonded to the upper end of the cross runner 8 at both ends to obtain the casting mold group;

[0053] S4. Dip the casting mold group into the surface layer slurry, cover a layer of zirconia sand after dipping, and then dry to obtain a mold group one, the surface layer slurry comprises silica sol and zirconia powder, the weight ratio of the silica sol and the zirconia powder is 2.5:10.5, the viscosity of the surface layer slurry is 55 S, the drying time is 6h, and the drying temperature is 26℃;

[0054] S5. Dip the mold group one prepared in step S4 into the back layer slurry, cover a layer of mullite sand after dipping, and then dry to obtain a mold group two, the back layer slurry comprises silica sol and mullite powder, the mass ratio is 1:2.5, the viscosity of the back layer slurry is 20 S, the drying time is 12h, and the drying temperature is 26℃;

[0055] S6. Repeat step S5 at least five times to obtain a mold group three, knock off the exhaust port 1 of the mold group three to obtain a mold group four, and the structure of the mold group four is as shown in Figure 4 ;

[0056] S7. The mold four is fired at a firing temperature of 1000 DEG C for 1 h, then the mold shell of the mold four is directly cleaned by compressed air, and the molten metal is poured into the mold shell after preheating to 1150 DEG C to obtain the casting.

[0057] The knock-out exhaust port of the exhaust plug of the castings obtained in Examples 1-3 is located at the lower end of the second exhaust section 2, and foreign matters cannot fall into the knock-out exhaust port, so it is not necessary to plug the knock-out exhaust port with refractory material.

[0058] The preparation process of the castings with the plugging-free exhaust plug of the present application simplifies the forming scheme of the conventional mold shell exhaust plug, and eliminates the process of plugging the exhaust plug with refractory material after firing, thereby improving the work efficiency and eliminating the quality risk.

[0059] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the examples, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A process for the production of a casting with a free-running vent plug, characterized in that: The method comprises the following steps: S1. Design the structure of the exhaust plug, which comprises a first exhaust section (3), a transition section (5), and a second exhaust section (2), one end of the transition section (5) is connected to the first exhaust section (3), the other end of the transition section (5) is connected to the second exhaust section (2), and an exhaust port (1) is arranged at one end of the second exhaust section (2) away from the transition section (5); S2. Design the exhaust plug wax mold, and inject wax into the designed mold to obtain the exhaust plug wax mold (6); S3. Design the casting mold group, which comprises a machine case (7) and a cross runner (8) arranged at the upper end of the machine case (7), and the exhaust plug wax mold (6) is arranged at both sides of the upper end of the cross runner (8); S4. Dip the casting mold group into the surface layer slurry, cover it with a layer of zirconia sand after dipping, and then dry to obtain mold group one; S5. Dip the mold group one prepared in step S4 into the back layer slurry, cover it with a layer of mullite sand after dipping, and then dry to obtain mold group two; S6. Repeat step S5 at least five times to obtain mold group three, knock off the exhaust port (1) of the mold group three to obtain mold group four; S7. Bake the mold group four, clean the mold shell of the mold group four with compressed air, preheat to 1000-1150℃, and then pour to obtain the casting; The structure of the exhaust plug in step S1 is L-shaped, the length of the first exhaust section (3) is greater than the length of the second exhaust section (2), and a reinforcing rib (4) is arranged at one end of the first exhaust section (3) away from the transition section (5); The exhaust plug wax mold in step S2 comprises a lower mold (9), an upper mold (10), a wax pressing channel (11), and an exhaust plug cavity (12), two groups of exhaust plug assemblies are arranged in parallel in the lower mold (9), the wax pressing channel (11) is arranged between the two groups of exhaust plug assemblies, each group of exhaust plug assemblies comprises a plurality of exhaust plug cavities (12) arranged at intervals, each exhaust plug cavity (12) is inclinedly provided with an exhaust channel (13) at one end close to the side edge of the lower mold (9), and the upper mold (10) is arranged at the upper end of the lower mold (9).

2. Process for the production of castings with a vent plug that does not clog, according to claim 1, characterized in that: The diameter of the exhaust port (1) in step S1 is 6mm.

3. The process for the production of a casting with a gassing plug free of clogging according to claim 1, characterized in that: The pressure of wax injection in step S2 is 15-25Bar, the wax temperature is 51-61℃, the injection time is 15-25s, the pressure maintaining time is 5-15s, and the injection flow is 75-85cc / s.

4. The process for producing a casting with a vent plug free of clogging according to claim 1, characterized in that: The surface layer slurry in step S4 comprises silica sol and zirconia powder, the weight ratio of the silica sol and the zirconia powder is (2-2.5):(10-10.5), and the viscosity of the surface layer slurry is 45-55 S.

5. The process for producing a casting with a vent plug free of clogging according to claim 1, characterized in that: The back layer slurry in step S5 comprises silica sol and mullite powder, the mass ratio is 1:(2-2.5), and the viscosity of the back layer slurry is 15-20 S.

6. The process for producing a cast part with a vent plug free of clogging according to claim 1, characterized in that: The drying time in step S4 is 4-6h, and the drying temperature is 20-26℃; the drying time in step S5 is 8-12h, and the drying temperature is 20-26℃.

7. The process for producing a cast part with a vent plug free of clogging according to claim 1, characterized in that: The baking temperature in step S7 is 900-1000℃, and the baking time is 1-3h.

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