Heat-resistant steel material complex volute investment casting and production process thereof

Abstract

The invention belongs to the technical field of investment casting, and particularly relates to a heat-resistant steel material complex volute type investment casting and a production process thereof.The production process comprises the following steps that S1, a split water-soluble wax core is manufactured and assembled according to a to-be-machined product; s2, when a product wax mold is pressed, the assembled water-soluble wax core is placed in a product mold, and then the product wax mold is pressed; s3, removing a water-soluble wax core from the product wax mold, and then assembling trees to obtain a pouring system; s4, a shell is manufactured through a double-face-layer technology, and the shell manufacturing process comprises the sand filling technology, the repeated grouting technology and the slurry pre-sealing technology; s5, dewaxing is conducted on the shell, then pre-roasting treatment is conducted, and furnace cooling is conducted; step S6, pouring of a product to be processed; and S7, after pouring is completed, vibration shelling is conducted, and a casting is obtained. The water-soluble wax core is combined, the volute and the assembly parts of the volute are subjected to one-time molding through investment casting, the welding process is omitted, and the quality of volute investment castings can be greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of investment casting, and in particular relates to a complex volute-type investment casting made of heat-resistant steel and a production process thereof. Background Art

[0002] Currently, volutes are difficult to produce through machining, often using investment casting. Some volutes made from heat-resistant steel cannot be assembled directly, but instead require welding other parts together to form an assembly, which is then machined to create the desired product. This welding process can easily lead to problems such as leaks and misalignment, potentially compromising the overall quality of the casting. Summary of the Invention

[0003] The present invention aims to overcome the shortcomings of the prior art by providing a complex volute-type investment casting made of heat-resistant steel and a production process thereof. By incorporating a water-soluble wax core and employing a one-step investment casting method for the volute and its assembly, the present invention eliminates the need for welding and manufactures complex volute components through investment casting, significantly improving the quality of volute-type investment castings.

[0004] To achieve the above technical objectives, the technical solution adopted in the embodiment of the present invention is: In a first aspect, an embodiment of the present invention provides a production process for complex volute-type investment castings made of heat-resistant steel, comprising the following steps: Step S1, assembling a water-soluble wax core: preparing a water-soluble wax core according to the product to be processed, wherein the inner hollow portion of the product to be processed adopts a split water-soluble wax core solution, firstly extruding a first water-soluble wax core and a second water-soluble wax core separately, and then assembling the first water-soluble wax core and the second water-soluble wax core; Step S2, preparing a product wax mold: making a product wax mold according to the product to be processed, placing the water-soluble wax core assembled in step S1 in the product mold when pressing the product wax mold, and then pressing the product wax mold; Step S3, removing the water-soluble wax core from the wax mold of the product obtained in step S2 and then assembling the mold, the resulting casting system includes a pouring cup, a runner, a side runner, and an ingate; Step S4, shell preparation: using a double-layer process to make the shell, the shell making process includes sand filling, multiple grouting and pre-sealing grouting process; Step S5: Dewaxing the shell mold obtained in step S4 using a steam dewaxing kettle. After dewaxing, the shell mold is left standing for more than 12 hours. The shell mold is then pre-baked at a temperature of 850-1000°C. After baking for more than 2 hours, the temperature is lowered with the furnace. After cooling to below 400°C, the shell mold is removed. Step S6, pouring of the product to be processed: when pouring the product, the temperature of the mold shell is 1050±20°C, and the temperature of the molten steel is 1630-1640°C; Step S7: After pouring is completed, the outer surface mold shell is first removed by vibration shelling. The refractory clay used for sand filling is also removed in this process, and the poured zircon sand is also removed; then the slurry poured into the inner cavity is cleaned by hydraulic sand cleaning; after hydraulic sand cleaning, the remaining mold shell is removed by dry sand cleaning to obtain a casting.

[0005] Furthermore, the ingates in step S3 include a first ingate, a second ingate, a third ingate, a fourth ingate, a fifth ingate and a sixth ingate.

[0006] Furthermore, the pouring cup is arranged perpendicularly to the runner, and the side runner includes a first side runner, a second side runner, a third side runner, a fourth side runner and a fifth side runner, the inlet ends of the first side runner, the second side runner, the fourth side runner and the fifth side runner are all connected to the runner, the outlet end of the first side runner is connected to the product wax mold through the fifth ingrate, the outlet end of the second side runner is connected to the product wax mold through the first ingrate, the third side runner is connected to the product wax mold through the second ingrate, the fourth side runner is connected to the product wax mold through the third ingrate, the fifth side runner is connected to the product wax mold through the fourth ingrate, and the runner is connected to the product wax mold through the sixth ingrate; An outlet end of the fourth side runner is communicated with the third side runner.

[0007] Furthermore, the cross section of the first ingates is an isosceles trapezoid, with an oblique angle of 15-25° and a height of 35±2 mm. The inner and outer edges of the first ingates are designed to be arc-shaped along the edge of the casting, with an arc length of 35-50 mm, and there are three of them in total. The second ingates are truncated cone-shaped, with a diameter of 11-15 mm at the plane connecting with the product wax mold, a diameter of 20-26 mm at the plane connecting with the third side runner, and a height of 25-35 mm, with a total of one; The cross section of the third ingates is an isosceles trapezoid, with an oblique angle of 15-25°, a height of 35-45 mm, and a length of 30-35 mm, with a total of 4; The fourth ingates are truncated cone-shaped, with a diameter of 8-11 mm on the plane connecting with the product wax mold, a diameter of 14-18 mm on the plane connecting with the fifth side runner, and a height of 20-30 mm, with a total of 8; The cross section of the fifth ingates is an isosceles trapezoid, with an oblique angle of 15-25°, a height of 35-45 mm, and a length of 25-35 mm, with a total of one; The sixth ingates are contoured ingates, shaped like the number "8", with two circles having diameters of 6-8mm at the connection with the product wax mold and 10-12mm at the connection with the runner.

[0008] Furthermore, in step S4, when making the shell, the surface layer and the second layer are made of 80-120 mesh zircon sand, and the drying time is 10-14 hours; The third and fourth layers are made of 60-80 mesh mullite sand, and the drying time is 16-20 hours; After the four layers are completed, pre-slurry is applied and dried for 20-24 hours; The five layers use 30-60 mesh mullite sand, and the drying time is 20-24 hours.

[0009] Furthermore, during grouting in step S4, the runner portion of the volute is grouted in four steps. During the first grouting, the pouring cup of the volute is placed downward, and grouting is performed from the pouring gate of the fourth side runner, until the portion below the pouring gate of the fourth side runner is filled with slurry. 6-8 hours after the first grouting is completed, rotate the module 90° counterclockwise and grout the second area; 6-8 hours after the second grouting is completed, rotate the module 90° counterclockwise and grout the third area; 6-8 hours after the third grouting is completed, rotate the module 90° counterclockwise again. After the third grouting has dried for more than 8 hours; Check the grouting area and carry out grouting for the fourth time for any unfilled areas. Start sand filling operation after drying for more than 12 hours.

[0010] Furthermore, when filling sand in step S4, the second hole, the third hole, and the fourth hole are first sealed with refractory mud, and then 80-120 mesh zircon sand is poured into the cavity from the first hole.

[0011] Furthermore, after completing the sand filling + grouting in step S4, the mold shell is dried for more than 48 hours, and the 6th layer of shell is made. 16-30 mesh mullite sand is used for 6-8 layers, and the drying time is 12-16 hours. After completing the 8-layer shell, the grouting is sealed. When sealing, only the slurry is dipped, and no sand is poured.

[0012] Furthermore, during pouring in step S6, the mold shell is padded with refractory bricks with a thickness of 40-60 mm to prevent direct contact between the product and the sand tray.

[0013] In the second aspect, an embodiment of the present invention provides a complex volute-type investment casting made of heat-resistant steel material, which is produced using the production process described in the first aspect and includes the following components by mass fraction: carbon 0.25%-0.35%, silicon ≤1.75%, manganese ≤1.5%, phosphorus ≤0.04%, sulfur ≤0.04%, chromium 23%-27%, nickel 19%-22%, molybdenum ≤0.5%, and the balance is iron.

[0014] The technical solution provided by the embodiment of the present invention has the following beneficial effects: 1. The present invention combines a water-soluble wax core and adopts a one-step molding method of the volute and its assembly parts through investment casting, thereby eliminating the welding process, reducing product production costs, and eliminating a series of problems such as leakage and position deviation caused by poor welding, which can greatly improve the quality of volute investment castings.

[0015] 2. The present invention utilizes multiple grouting processes, combined with pre-seal and sand filling, to complete the shell production process. Existing techniques mostly use a monolithic ceramic core, which is complex and expensive, and requires removal. While the shell production process of the present invention is relatively complex, it is low-cost and easy to clean.

[0016] 3. No ceramic core is used when the cavity is extremely complex, which reduces production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure of the first water-soluble wax core in an embodiment of the present invention.

[0018] Figure 2 Schematic diagram of the structure of the second water-soluble wax core in an embodiment of the present invention.

[0019] Figure 3 It is a structural schematic diagram of a first water-soluble wax core and a second water-soluble wax core assembled together.

[0020] Figure 4 It is a structural schematic diagram of a product wax mold in an embodiment of the present invention.

[0021] Figure 5 It is a front view of the pouring system in an embodiment of the present invention.

[0022] Figure 6 It is a left side view of the pouring system in an embodiment of the present invention.

[0023] Figure 7 Schematic diagram of the placement of the shell during grouting in an embodiment of the present invention.

[0024] Figure 8 Schematic diagram of the structure of the area to be filled with grouting in an embodiment of the present invention.

[0025] Figure 9 It is a structural schematic diagram of the sealing hole and the sand filling hole during sand filling in an embodiment of the present invention.

[0026] Figure 10 Schematic diagram of the placement of refractory bricks during pouring in an embodiment of the present invention.

[0027] Explanation of the accompanying drawings: 1-first water-soluble wax core; 2-second water-soluble wax core; 3-pouring cup; 4-cross runner; 5-side runner; 6-ingredient; 7-second area; 8-third area; 9-first area; 10-second hole; 11-third hole; 12-fourth hole; 13-first hole; 14-refractory brick; 51-first side runner; 52-second side runner; 53-third side runner; 54-fourth side runner; 55-fifth side runner; 61-first ingredient; 62-second ingredient; 63-third ingredient; 64-fourth ingredient; 65-fifth ingredient; 66-sixth ingredient. DETAILED DESCRIPTION

[0028] In the description of the present invention, it should be understood that the directions or positional relationships indicated by directional words such as "inside, outside", "up, down", "left, right", etc. are usually based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention.

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0030] Example 1 A production process for complex volute-type investment castings made of heat-resistant steel material comprises the following steps: Step S1, assembling water-soluble wax core: make water-soluble wax core according to the product to be processed, the inner hollow part of the product to be processed adopts the split water-soluble wax core scheme, first squeeze out the first water-soluble wax core 1 and the second water-soluble wax core 2, as shown in FIG. Figure 1 and 2 As shown, the first water-soluble wax core 1 and the second water-soluble wax core 2 are assembled together, as shown in FIG. Figure 3 As shown; Step S2, prepare product wax mold: make product wax mold according to the product to be processed, place the water-soluble wax core assembled in step S1 in the product mold when pressing the product wax mold, and then press out the product wax mold, such as Figure 4 As shown; Step S3, remove the water-soluble wax core from the wax mold of the product obtained in step S2 and then assemble the mold. The resulting casting system includes a pouring cup 3, a runner 4, a side runner 5 and an inner gate 6. Figure 5 and 6 As shown, the cross-sectional area of ​​the runner is 40 mm × 50 mm; The ingates 6 include a first ingate 61 , a second ingate 62 , a third ingate 63 , a fourth ingate 64 , a fifth ingate 65 and a sixth ingate 66 .

[0031] The cross section of the first ingates 61 is an isosceles trapezoid with an oblique angle of 15-25° and a height of 35mm±2. The inner and outer edges of the first ingates 61 are designed to be arc-shaped along the edge of the casting with an arc length of 35-50mm. There are three of them in total. The second ingates 62 are truncated cone-shaped, with a diameter of 11-15 mm at the plane connecting to the product wax mold and a diameter of 20-26 mm at the plane connecting to the third side runner 53. The height is 25-35 mm. There is one in total. The third ingates 63 have a cross-section of an isosceles trapezoid, an oblique angle of 15-25°, a height of 35-45 mm, and a length of 30-35 mm. There are four of them in total. The fourth ingates 64 are truncated cone-shaped, with a diameter of 8-11 mm at the plane connecting to the product wax mold and a diameter of 14-18 mm at the plane connecting to the fifth side runner 55. The height is 20-30 mm, and there are 8 of them in total. The fifth ingrate 65 has an isosceles trapezoidal cross section with an oblique angle of 15-25°, a height of 35-45 mm, and a length of 25-35 mm. There is one ingrate in total. The sixth ingates 66 are contoured ingates shaped like the number "8", with diameters of two circles at the connection with the product wax mold being 6-8 mm, and diameters of two circles at the connection with the runner 4 being 10-12 mm.

[0032] The pouring cup 3 is arranged perpendicular to the runner 4. The side runner 5 includes a first side runner 51, a second side runner 52, a third side runner 53, a fourth side runner 54 and a fifth side runner 55. The inlet ends of the first side runner 51, the second side runner 52, the fourth side runner 54 and the fifth side runner 55 are all connected to the runner 4. The cross-sectional area of ​​the first side runner 51, the second side runner 52, the fourth side runner 54 and the fifth side runner 55 is 40 mm × 40 mm. The outlet end of the first side runner 51 is connected to the product wax mold through the fifth ingrate 65, the outlet end of the second side runner 52 is connected to the product wax mold through the first ingrate 61, the third side runner 53 is connected to the product wax mold through the second ingrate 62, the fourth side runner 54 is connected to the product wax mold through the third ingrate 63, the fifth side runner 55 is connected to the product wax mold through the fourth ingrate 64, and the runner 4 is connected to the product wax mold through the sixth ingrate 66; An outlet end of the fourth side runner 54 is communicated with the third side runner 53 .

[0033] Step S4, shell preparation: using a double-layer process to make the shell, the shell making process includes sand filling, multiple grouting and pre-sealing grouting process; When making the shell, the surface layer and the second layer are made of 80-120 mesh zircon sand, and the drying time is 10-14 hours; The third and fourth layers use 60-80 mesh mullite sand, and the drying time is 16-20 hours; After the four layers are completed, pre-seal the slurry and dry it for 20-24 hours; The fifth layer uses 30-60 mesh mullite sand and the drying time is 20-24 hours.

[0034] During grouting, the runner part of the volute is grouted in 4 times. In the first grouting, the pouring cup 3 of the volute is placed downward, and grouting is performed from the pouring gate of the fourth side pouring channel 54. A plastic bottle with a nozzle is used to fill the part below the pouring gate of the fourth side pouring channel 54 with slurry. Figure 7 and 8 As shown; 6-8 hours after the first grouting is completed, rotate the module 90° counterclockwise and grout the second area 7; 6-8 hours after the second grouting is completed, rotate the module 90° counterclockwise and grout the third area 8; 6-8 hours after the third grouting is completed, rotate the module 90° counterclockwise again. After the third grouting has dried for more than 8 hours; Check the grouting area and carry out grouting for the fourth time for any unfilled areas. Start sand filling operation after drying for more than 12 hours.

[0035] When filling sand, first seal the second hole 10, the third hole 11, and the fourth hole 12 with refractory mud, and then pour 80-120 mesh zircon sand into the cavity from the first hole 13. Figure 9 As shown; Pay special attention to the red area of ​​the first hole 13. This area is connected to the previous grouting area. When pouring sand to this position, it is necessary to shake it repeatedly 3-5 times to ensure that all the sand enters this area. After the inner cavity is completely filled, seal this hole with refractory mud.

[0036] After completing the sand filling and grouting, the mold shell is dried for more than 48 hours before the 6th layer of shell making is carried out. 16-30 mesh mullite sand is used for the 6th to 8th layers, and the drying time is 12-16 hours. After completing the 8th layer of shell making, the grouting is sealed. When sealing, only the slurry is dipped, and no sand is poured.

[0037] Step S5: Dewaxing the shell mold obtained in step S4 using a steam dewaxing kettle. After dewaxing, the shell mold is left standing for more than 12 hours. The shell mold is then pre-baked at a temperature of 850-1000°C. After baking for more than 2 hours, the temperature is lowered with the furnace. After cooling to below 400°C, the shell mold is removed. Step S6, pouring of the product to be processed: when pouring the product, the temperature of the mold shell is 1050±20°C, and the temperature of the molten steel is 1630-1640°C; When pouring, use refractory bricks 14 with a cross-sectional area of ​​50mm×80mm and a thickness of 40-60mm to pad the mold shell to avoid direct contact between the product and the sand tray. Figure 10 As shown; Step S7: After pouring is completed, the outer surface mold shell is first removed by vibration shelling. The refractory clay used for sand filling is also removed in this process, and the poured zircon sand is also removed; then the slurry poured into the inner cavity is cleaned by hydraulic sand cleaning; after hydraulic sand cleaning, the remaining mold shell is removed by dry sand cleaning to obtain a casting.

[0038] A complex volute-type investment casting made of heat-resistant steel is produced using the above-mentioned production process. The material is HK30ASTM A351 and includes the following components by mass: carbon 0.25%-0.35%, silicon ≤1.75%, manganese ≤1.5%, phosphorus ≤0.04%, sulfur ≤0.04%, chromium 23%-27%, nickel 19%-22%, molybdenum ≤0.5%, and the balance is iron.

[0039] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solutions of the present invention and are not limiting. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solutions of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A production process for complex spiral casing investment castings made of heat-resistant steel, characterized in that: The following steps are involved: Step S1, assembling the water-soluble wax core: manufacturing the water-soluble wax core according to the product to be processed, wherein the inner hollow part of the product to be processed adopts a split water-soluble wax core solution, firstly pressing out the first water-soluble wax core (1) and the second water-soluble wax core (2) respectively, and then assembling the first water-soluble wax core (1) and the second water-soluble wax core (2); Step S2, preparing a product wax mold: making a product wax mold according to the product to be processed, placing the water-soluble wax core assembled in step S1 in the product mold when pressing the product wax mold, and then pressing out the product wax mold; Step S3, removing the water-soluble wax core from the wax mold of the product obtained in step S2 and then assembling the mold, the resulting casting system includes a pouring cup (3), a cross runner (4), a side runner (5) and an inner gate (6); Step S4, preparation of the shell: the shell is made by a double-sided layer process, and the shell making process includes sand filling, multiple grouting and pre-sealing grouting processes; Step S5, dewaxing the shell obtained in step S4 with a steam dewaxing kettle, leaving it for more than 12 hours after dewaxing, and then pre-baking the shell at a temperature of 850-1000° C., and cooling it with the furnace after baking for more than 2 hours, and taking out the shell after cooling it to below 400° C.; Step S6, pouring of the product to be processed: when pouring the product, the temperature of the mold shell is 1050±20°C, and the temperature of the molten steel is 1630-1640°C; Step S7, after pouring is completed, the outer surface mold shell is first removed by vibration shelling, and the refractory mud used for sand filling is also removed in this process, and the poured zircon sand is also removed; then the slurry poured into the inner cavity is cleaned by hydraulic sand cleaning; after hydraulic sand cleaning, the residual mold shell is removed by dry sand cleaning to obtain a casting.

2. The production process of complex spiral casing investment castings made of heat-resistant steel according to claim 1, characterized in that: The gate (6) in step S3 includes a first gate (61), a second gate (62), a third gate (63), a fourth gate (64), a fifth gate (65) and a sixth gate (66).

3. The production process of complex spiral casing investment castings made of heat-resistant steel according to claim 2, characterized in that: The pouring cup (3) is arranged vertically with the runner (4); the side runner (5) comprises a first side runner (51), a second side runner (52), a third side runner (53), a fourth side runner (54) and a fifth side runner (55); the inlet ends of the first side runner (51), the second side runner (52), the fourth side runner (54) and the fifth side runner (55) are all connected to the runner (4); the outlet end of the first side runner (51) is connected to the runner (4) through the fifth inner gate. (65) is connected to the product wax mold, the outlet end of the second side runner (52) is connected to the product wax mold through the first ingates (61), the third side runner (53) is connected to the product wax mold through the second ingates (62), the fourth side runner (54) is connected to the product wax mold through the third ingates (63), the fifth side runner (55) is connected to the product wax mold through the fourth ingates (64), and the runner (4) is connected to the product wax mold through the sixth ingates (66); The outlet end of the fourth side runner (54) is in communication with the third side runner (53).

4. The production process of complex spiral casing investment castings made of heat-resistant steel material according to claim 2, characterized in that: The cross section of the first ingates (61) is an isosceles trapezoid, with an oblique angle of 15-25° and a height of 35±2 mm. The inner and outer edges of the first ingates (61) are designed to be arc-shaped along the edges of the casting, with an arc length of 35-50 mm, and there are three of them in total; The second inner gate (62) is truncated cone-shaped, with a plane diameter of 11-15 mm for connecting with the product wax mold, a plane diameter of 20-26 mm for connecting with the third side runner (53), and a height of 25-35 mm, with a total of one; The cross section of the third ingates (63) is an isosceles trapezoid, the bevel angle is 15-25°, the height is 35-45 mm, the length is 30-35 mm, and there are 4 of them in total; The fourth inner gate (64) is truncated cone-shaped, with a plane diameter of 8-11 mm for connecting with the product wax mold, a plane diameter of 14-18 mm for connecting with the fifth side runner (55), and a height of 20-30 mm, with a total of 8; The cross section of the fifth ingates (65) is an isosceles trapezoid, the oblique angle is 15-25°, the height is 35-45 mm, the length is 25-35 mm, and there is one in total; The sixth ingates (66) are contoured ingates, shaped like the number "8", with two circles having diameters of 6-8 mm at the connection with the product wax mold and two circles having diameters of 10-12 mm at the connection with the runner (4).

5. The production process of complex spiral casing investment castings made of heat-resistant steel material according to claim 1, characterized in that: When making the shell in step S4, the surface layer and the second layer are made of 80-120 mesh zircon sand, and the drying time is 10-14 hours; The third and fourth layers are made of 60-80 mesh mullite sand, and the drying time is 16-20 hours; After the four layers are completed, pre-slurry is applied and dried for 20-24 hours; The five layers use 30-60 mesh mullite sand, and the drying time is 20-24 hours.

6. The production process of complex spiral casing investment castings made of heat-resistant steel material according to claim 3, characterized in that: During grouting in step S4, the flow channel portion of the volute is grouted in four steps. During the first grouting, the pouring cup (3) of the volute is placed downward, and grouting is performed from the pouring port of the fourth side pouring channel (54), so that the portion below the pouring port of the fourth side pouring channel (54) is filled with slurry; 6-8 hours after the first grouting is completed, the module is rotated 90° counterclockwise to grout the second area (7); 6-8 hours after the second grouting is completed, the module is rotated 90° counterclockwise to grout the third area (8); 6-8 hours after the third grouting is completed, rotate the module 90° counterclockwise again. After the third grouting is dried for more than 8 hours; Check the grouting area and carry out the fourth grouting for any unfilled areas. Start the sand filling operation after drying for more than 12 hours.

7. The production process of complex spiral casing investment castings made of heat-resistant steel according to claim 1 or 6, characterized in that: When filling the sand in step S4, firstly, the second hole (10), the third hole (11) and the fourth hole (12) are sealed with refractory mud, and then 80-120 mesh zircon sand is poured into the cavity from the first hole (13).

8. The production process of complex spiral casing investment castings made of heat-resistant steel according to claim 1 or 7, characterized in that: After the sand filling + grouting is completed in step S4, the mold shell is dried for more than 48 hours, and the 6th layer of shell is made. 16-30 mesh mullite sand is used for 6-8 layers, and the drying time is 12-16 hours. After the 8th layer of shell is completed, the grouting is sealed. When sealing, only the slurry is dipped, and no sand is poured.

9. The production process of complex spiral casing investment castings made of heat-resistant steel material according to claim 1, characterized in that: Step S6: During pouring, the mold shell is padded with refractory bricks with a thickness of 40-60 mm to prevent the product from directly contacting the sand tray.

10. A complex spiral casing investment casting made of heat-resistant steel, characterized in that: The invention is prepared by the production process according to any one of claims 1 to 9, and comprises the following components by mass fraction: carbon 0.25%-0.35%, silicon ≤1.75%, manganese ≤1.5%, phosphorus ≤0.04%, sulfur ≤0.04%, chromium 23%-27%, nickel 19%-22%, molybdenum ≤0.5%, and the balance is iron.

Images