CN113798437B - Casting process of double-channel impeller made of duplex stainless steel - Google Patents
Casting process of double-channel impeller made of duplex stainless steel Download PDFInfo
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- CN113798437B CN113798437B CN202111207607.3A CN202111207607A CN113798437B CN 113798437 B CN113798437 B CN 113798437B CN 202111207607 A CN202111207607 A CN 202111207607A CN 113798437 B CN113798437 B CN 113798437B
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- 238000005266 casting Methods 0.000 title claims abstract description 66
- 229910001039 duplex stainless steel Inorganic materials 0.000 title claims abstract description 14
- 239000003110 molding sand Substances 0.000 claims abstract description 33
- 238000004519 manufacturing process Methods 0.000 claims abstract description 10
- 239000011258 core-shell material Substances 0.000 claims description 40
- 239000004576 sand Substances 0.000 claims description 33
- 238000000465 moulding Methods 0.000 claims description 30
- 230000009977 dual effect Effects 0.000 claims description 23
- 229910001220 stainless steel Inorganic materials 0.000 claims description 21
- 239000010935 stainless steel Substances 0.000 claims description 21
- 229910000831 Steel Inorganic materials 0.000 claims description 20
- 238000010438 heat treatment Methods 0.000 claims description 20
- 239000010959 steel Substances 0.000 claims description 20
- 244000035744 Hura crepitans Species 0.000 claims description 12
- 239000011347 resin Substances 0.000 claims description 7
- 229920005989 resin Polymers 0.000 claims description 7
- 239000003795 chemical substances by application Substances 0.000 claims description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 4
- 239000011248 coating agent Substances 0.000 claims description 4
- 238000000576 coating method Methods 0.000 claims description 4
- 239000000843 powder Substances 0.000 claims description 4
- 229910052845 zircon Inorganic materials 0.000 claims description 4
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 claims description 4
- 239000007800 oxidant agent Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000003832 thermite Substances 0.000 claims description 3
- 238000000265 homogenisation Methods 0.000 claims description 2
- 239000012774 insulation material Substances 0.000 claims description 2
- 238000000034 method Methods 0.000 abstract description 10
- 239000000463 material Substances 0.000 abstract description 7
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- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
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- 238000004140 cleaning Methods 0.000 description 2
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- 229910000592 Ferroniobium Inorganic materials 0.000 description 1
- 229910001200 Ferrotitanium Inorganic materials 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- NCJRLCWABWKAGX-UHFFFAOYSA-N [Si].[Ca].[Ba] Chemical compound [Si].[Ca].[Ba] NCJRLCWABWKAGX-UHFFFAOYSA-N 0.000 description 1
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- 229910001566 austenite Inorganic materials 0.000 description 1
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- ZFGFKQDDQUAJQP-UHFFFAOYSA-N iron niobium Chemical compound [Fe].[Fe].[Nb] ZFGFKQDDQUAJQP-UHFFFAOYSA-N 0.000 description 1
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/02—Sand moulds or like moulds for shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/08—Features with respect to supply of molten metal, e.g. ingates, circular gates, skim gates
- B22C9/088—Feeder heads
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/10—Cores; Manufacture or installation of cores
- B22C9/103—Multipart cores
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C9/00—Moulds or cores; Moulding processes
- B22C9/22—Moulds for peculiarly-shaped castings
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D15/00—Casting using a mould or core of which a part significant to the process is of high thermal conductivity, e.g. chill casting; Moulds or accessories specially adapted therefor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
- B22D27/04—Influencing the temperature of the metal, e.g. by heating or cooling the mould
- B22D27/045—Directionally solidified castings
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0068—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for particular articles not mentioned below
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
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- Engineering & Computer Science (AREA)
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- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Molds, Cores, And Manufacturing Methods Thereof (AREA)
Abstract
The invention relates to a double-channel impeller casting process of duplex stainless steel, which comprises the following steps: 1) sand core preparation, 2) outer mold manufacturing, 3) casting, 4) box opening and shakeout, wherein the sand core comprises an upper impeller sand core, a lower impeller sand core, a central core rod sand core, a first molding sand core and a second molding sand core, the cast double-runner impeller is accurate in structure, good in product quality, simple in process, high in production efficiency, low in rejection rate, and cast by adopting a duplex stainless steel material, and has the advantages of corrosion resistance, high strength, long service life, low life cycle cost and the like.
Description
Technical Field
The invention relates to the field of casting, in particular to a double-channel impeller casting process for duplex stainless steel.
Background
The double-runner impeller casting has the characteristics that the wall thickness of each part is greatly changed, the blades are very thin (only 8-10 mm), the using working condition is bad (high temperature, high pressure, corrosion, high-speed rotation and the like), so the quality requirement of the casting is very high, the double-runner impeller casting has the defects of complex structure, narrow runner, pressure bearing requirement, more manufacturing procedures, large casting difficulty, complex process, high rejection rate, high cost and the like, and the double-phase stainless steel is extremely easy to generate casting defects such as cracks, sand bonding and the like in the casting process due to the material characteristics.
Disclosure of Invention
In view of the foregoing shortcomings of the prior art, it is an object of the present invention to provide a dual phase stainless steel dual flow impeller casting process that solves one or more of the problems of the prior art.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
a double-channel impeller casting process of duplex stainless steel comprises the following steps:
1) Preparing a sand core: the sand core comprises an upper impeller sand core, a lower impeller sand core, a central core rod sand core, a first molding sand core and a second molding sand core, wherein the upper impeller sand core is formed by processing a first molding core shell, the lower impeller sand core is formed by processing a second molding core shell, the central core rod sand core is formed by processing a third molding core shell, the first molding sand core and the second molding sand core are formed by processing a fourth molding core shell, a plurality of the first molding sand cores and a plurality of the second molding sand cores are assembled in the grooves of the upper impeller sand core and the lower impeller sand core, and the central core rod sand core is inserted in the central hole of the lower impeller sand core and spliced into an integral sand core;
2) And (3) manufacturing an outer mold: processing an outer mold according to the appearance of the product;
3) Casting: firstly placing an outer mold in a sand box to form an outer mold sand mold, then placing an integral sand core into the outer mold sand mold, and finally injecting molten steel into the sand mold through a pouring system for casting molding;
4) Unpacking and shakeout: and opening the sand box, shakeout, and taking out the molded casting.
The upper impeller sand core and the lower impeller sand core are made of resin sand, and the first molding sand core and the second molding sand core are made of chromite sand.
As a further improvement of the above technical scheme:
and when the upper impeller sand core and the lower impeller sand core are processed, chromite sand is sprayed into the first forming core shell and the second forming core shell, resin sand is filled in, the outer sides of the upper impeller sand core and the lower impeller sand core form the outer surface of the chromite sand, and the first forming sand core and the second forming sand core which are made of the chromite sand are clamped into grooves of the upper impeller sand core and the lower impeller sand core.
The integral sand core is positioned at the contact part of molten steel, and is pre-coated with three times of alcohol-based zircon powder coating.
The sand box comprises an upper box and a lower box, a first riser is arranged at the position of the upper box, which is located at the shaft hole of the double-flow-passage impeller, a second riser is arranged at the joint of the upper box, which is located at the upper side of the double-flow-passage impeller, and the blade, and a third riser is arranged at the joint of the lower box, which is located at the lower side of the double-flow-passage impeller, which is located at the joint of the upper side of the double-flow-passage impeller, and the blade.
The sizes of the first riser, the second riser and the third riser are 2-2.5 times of the corresponding part hot joint.
The first riser, the second riser and the third riser are all heating risers, and the heating risers are made by adding thermite, fluxing agent, oxidant and heat insulation materials during riser manufacturing.
And an external chill is arranged at the position of the lower box body between the third riser heads.
And removing the first riser, the second riser and the third riser after the box opening and the shakeout are completed.
Before the first riser, the second riser and the third riser are removed, homogenization heat treatment is needed, and after the first riser, the second riser and the third riser are removed, solution heat treatment is needed.
Compared with the prior art, the invention has the following beneficial technical effects:
1) The upper impeller sand core, the lower impeller sand core, the central core rod sand core, the first molding sand core and the second molding sand core are respectively processed through the first molding core shell, the second molding core shell, the third molding core shell and the fourth molding core shell, and then the upper impeller sand core, the lower impeller sand core, the central core rod sand core, the first molding sand core and the second molding sand core are assembled into an integral sand core, so that the cast double-runner impeller has accurate structure, good product quality, simple process, high production efficiency and low rejection rate;
2) When the upper impeller sand core and the lower impeller sand core are processed and molded, the first molding core shell and the second molding core shell are sprayed with chromite sand, the outer surface of the chromite sand is outside the resin sand, and sand sticking and sintering of the inner cavities of the first molding core shell and the second molding core shell at high temperature are avoided;
3) The integral sand core is precoated with three times of alcohol-based zircon powder coating, so that the roughness of the blade part of the double-flow-passage impeller can be ensured to meet the requirement;
4) When casting, the upper box and the lower box of the sand box are arranged at the positions of the shaft holes of the double-runner impeller, the upper box is arranged at the joint position of the upper side mouth ring of the double-runner impeller and the blades, the lower box is arranged at the joint position of the lower side mouth ring of the double-runner impeller and the blades, and the third riser is arranged at the joint position of all the riser, so that molten steel can be orderly solidified towards the riser direction from top to bottom, the supplement of molten steel can be achieved in the whole solidification and crystallization process of the casting, the lock hole and shrinkage cavity in the casting are finally introduced into the riser, and finally a compact and complete pump body casting is obtained;
5) An external chill with a chilling effect is arranged between third risers at the mouth ring of the lower box of the sand box, so that the orderly solidification direction of castings can be enhanced, under the chilling effect of the external chill, molten metal of the lower box is inevitably cooled earlier than other parts, when the lower box surface is solidified, molten steel which is required to be fed is continuously supplemented by the molten steel which is not solidified at the upper part, and the castings can be sequentially solidified from top to bottom, thereby achieving the purpose that the riser parts are later than the castings;
6) The first riser, the second riser and the third riser are all heating risers, the feeding effect of the heating risers is far better than that of the conventional heat-preserving riser, and a special heating agent for casting is added into the riser immediately after casting is finished, so that the solidification time of the riser is prolonged.
Drawings
Fig. 1 shows a schematic structural view of a dual-channel impeller casting.
Fig. 2 shows a schematic structural view of a dual channel impeller casting with riser construction.
FIG. 3 shows a schematic diagram of the assembly of an upper impeller core, a lower impeller core, and a central core rod core used in the dual-phase stainless steel dual-runner impeller casting process of the present invention.
Fig. 4 shows an assembly schematic of an upper impeller core, a first molded core, a second molded core used in the dual-phase stainless steel dual-channel impeller casting process of the present invention.
Fig. 5 shows an assembly schematic of a lower impeller core, a first molded core, a second molded core used in the dual-phase stainless steel dual-channel impeller casting process of the present invention.
Fig. 6 shows a schematic structural view of a first forming core shell used in the dual phase stainless steel dual flow impeller casting process of the present invention.
Fig. 7 shows a schematic structural view of a second molded core-shell used in the dual phase stainless steel dual flow impeller casting process of the present invention.
Fig. 8 shows a schematic structural view of a third forming core shell used in the dual phase stainless steel dual flow impeller casting process of the present invention.
Fig. 9 shows a schematic structural view of a fourth forming core-shell used in the dual phase stainless steel dual flow impeller casting process of the present invention.
Fig. 10 shows a schematic structural view of an outer mold used in the dual phase stainless steel dual flow impeller casting process of the present invention.
The reference numerals in the drawings:
1. a sand core of an upper impeller; 2. a lower impeller sand core; 3. a central core rod sand core; 4. a first molding core; 5. a second molding core; 6. a first forming core shell; 7. a second molded core shell; 8. a third forming core shell; 9. a fourth forming core shell; 10. an outer mold; 11. a first riser; 12. a second riser; 13. a third riser; 14. and (5) an external chill.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the following more detailed description of the device according to the present invention is given with reference to the accompanying drawings and the detailed description. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for the purpose of facilitating and clearly aiding in the description of embodiments of the invention. For a better understanding of the invention with objects, features and advantages, refer to the drawings. It should be understood that the structures, proportions, sizes, etc. shown in the drawings are for illustration purposes only and should not be construed as limiting the invention to the extent that it would be understood by those skilled in the art, and that any structural modifications, proportional changes, or dimensional adjustments made in the drawings should not be construed as unduly limiting the invention, but rather as falling within the scope of the invention herein disclosed.
As shown in fig. 1 to 10, the dual-phase stainless steel dual-channel impeller casting process of the present embodiment,
adopting super duplex stainless steel 5A molten steel;
super duplex stainless steel ASTM A955/A955M-2018 5A standard component
PREN＝％Cr+3.3*％Mo+16*％N
The smelting process method of VOD refining and intermediate frequency furnace is adopted, the characteristics of duplex stainless steel are considered, the smelting technology is different from that of common products, so that the process method of VOD furnace refining and intermediate frequency induction furnace smelting is adopted, a high-quality VOD furnace refining stainless steel material and a high-quality alloy material (ferromolybdenum, metallic chromium, chromium nitride iron and the like) with low P, S are used as raw materials, so that the manufacturing cost is reduced, the content of various elements in molten steel is strictly controlled, the smelting temperature is controlled, the content of C is reduced as much as possible, the oxidation loss of Cr is reduced, the smelting analysis components are adjusted according to a ferrite calculation formula in ASTM A955/A955M-2018, the ferrite content in final molten steel is controlled to be about 45%, and the PREMN (corrosion equivalent weight) value is ensured to be greater than 40. To further improve corrosion resistance, ferrotitanium or rare earth silicon calcium barium is used to replace pure aluminum for deoxidation, and trace ferroniobium is added to refine grains so as to achieve satisfactory smelting effect, and chemical components are controlled in molten steel (see table below)
The duplex stainless steel material has an alpha+gamma duplex structure, so that the performance of the duplex stainless steel material has the characteristics of ferrite stainless steel and austenite stainless steel, and the duplex stainless steel material has the composition characteristics of ultralow carbon (less than or equal to 0.03%), PRE value (more than or equal to 40), high chromium (more than or equal to 24%), high molybdenum (more than or equal to 4%), and high nitrogen (0.1% -0.3%), and has very high corrosion resistance.
The casting process of the duplex stainless steel double-runner impeller of the embodiment comprises the following steps:
1) Preparing a sand core: the sand core comprises an upper impeller sand core 1, a lower impeller sand core 2, a central core rod sand core 3, a first molding sand core 4 and a second molding sand core 5, wherein the upper impeller sand core 1 is formed by processing a first molding core shell 6, the lower impeller sand core 2 is formed by processing a second molding core shell 7, the central core rod sand core 3 is formed by processing a third molding core shell 8, the first molding sand core 4 and the second molding sand core 5 are formed by processing a fourth molding core shell 9, a plurality of first molding sand cores 4 and a plurality of second molding sand cores 5 are assembled in the grooves of the upper impeller sand core 1 and the lower impeller sand core 2, the central core rod sand core 3 is inserted in the central hole of the lower impeller sand core 2, and the upper impeller sand core 1 and the lower impeller sand core 2 are spliced into an integral sand core;
2) And (3) manufacturing an outer mold: machining an outer die 10 according to the appearance of the product;
3) Casting: firstly placing an outer mold 10 between an upper box and a lower box of a sand box, forming a cavity between the upper box and the lower box, then opening the upper box and the lower box to place an integral sand core in the cavity to form a cavity, arranging a first riser 11 at the position of the upper box of the sand core at a shaft hole of a double-runner impeller, arranging five second risers 12 at the junction of an upper side mouth ring of the double-runner impeller and a blade, arranging five third risers 13 at the junction of a lower side mouth ring of the double-runner impeller and the blade, injecting double-phase stainless steel liquid into the cavity through a pouring system, controlling the pouring temperature to 1570-1590 ℃, sequentially solidifying and forming the liquid steel in the cavity, immediately removing a fastening device after the casting is completely solidified (about 30-60 min) after the casting is finished, and cooling the formed casting in the cavity to be less than 300 ℃;
4) Unpacking and shakeout: the heat preservation time of the formed casting in the sand box is not less than 72h, the casting to be formed can be opened after being cooled to the temperature below 150 ℃ in the sand box, the formed casting (comprising a pouring system) is strictly forbidden to be impacted or collided in the process of transferring after being opened, and a shakeout machine is strictly forbidden to be used for sand removal after the opening of the box, so that manual sand removal is adopted. Manually cleaning loose sand on the surface of an inner cavity of the formed casting, strictly preventing knocking and collision, closing doors and windows during opening and sand cleaning, and strictly preventing a fan from blowing;
5) First heat treatment: the first heat treatment is to homogenize the formed casting;
6) And (3) removing a riser: removing the first riser 11, the second riser 12 and the third riser 13 from the formed casting;
7) And (3) performing secondary heat treatment: the second heat treatment is carried out by solid solution treatment in a heat treatment furnace after the riser is treated (within 4 hours).
The first forming core shell 6, the second forming core shell 7 and the third forming core shell 8 are made of aluminum alloy materials, and are formed through one-time processing by programming a numerical control machine tool, and the dimensional accuracy after finishing can reach 0.003-0.005mm.
The upper impeller sand core 1 and the lower impeller sand core 2 are made of resin sand, the first molding sand core 4 and the second molding sand core 5 are made of chromite sand, chromite sand is sprayed into the first molding core shell 6 and the second molding core shell 7 when the upper impeller sand core 1 and the lower impeller sand core 2 are processed, then the resin sand is filled, the outer sides of the upper impeller sand core 1 and the lower impeller sand core 2 form the outer surface of the chromite sand, the first molding sand core 6 and the inner cavity of the second molding core shell 7 are prevented from being bonded with sand at high temperature, the upper impeller sand core 1 and the lower impeller sand core 2 are burnt, after the first molding sand core 4 and the second molding sand core 5 which are made of chromite sand are clamped into the grooves of the upper impeller sand core 1 and the lower impeller sand core 2, and the central core rod sand core 3 is inserted into the central hole of the lower impeller sand core 2, and the whole sand core is formed.
The integral sand core is positioned at the contact position of molten steel, and is coated with alcohol-based zircon powder coating for three times in advance, so that the roughness of the blade position of the double-flow-passage impeller can be ensured to meet the requirement, and the roughness of the surface of the blade can reach Ra25.
The sizes of the first riser 11, the second riser 12 and the third riser 13 are 2-2.5 times of the corresponding part hot spots, and the first riser 11, the second riser 12 and the third riser 13 are arranged to enable molten steel to be orderly solidified towards the riser from top to bottom, so that the supplement of molten steel can be obtained in the whole solidification and crystallization process of a casting, and a lock hole and a shrinkage cavity in the casting are introduced into the riser at last, and a compact and complete pump body casting is finally obtained.
The pouring system adopts an open pouring system, a sprue: and (3) a cross gate: ingate = 1: (1.5-2): (2.0-3.0), pouring molten steel enters the cross runner through the sprue and then enters the cavity through the ingate, so that the heat of the molten steel can be uniformly dispersed, and the scouring and the thermal influence on the sand core are reduced.
The first riser 11, the second riser 12 and the third riser 13 are all heating risers, the heating risers are made by adding thermite, fluxing agent, oxidant and heat insulation and heat preservation materials when the risers are manufactured, the feeding effect of the heating risers is far better than that of the conventional heat preservation risers, and the special heating agent for casting is added into the risers immediately after casting is finished, so that the solidification time of the risers is prolonged.
Five external chill 14 are arranged at the position of the lower box body between the third riser 13, the placing distance between the external chill 14 is 10-15mm, the thickness of the external chill 14 is about 70% of the thickness of the mouth ring, the external chill 14 with chilling effect can strengthen the orderly solidification direction of castings, under the chilling effect of the external chill 14, the molten metal of the lower box is inevitably cooled earlier than other parts, when the lower box is solidified, the molten steel required to be fed can be continuously supplemented by the upper non-solidified molten steel, so that the castings can be sequentially solidified from top to bottom, and the purpose that the riser part is later than the solidification of the castings is achieved.
The single casting piece of the double-channel stainless steel impeller cast with the maximum wall thickness of 120mm and the minimum wall thickness of 8mm is about 660 Kg.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which shall fall within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (6)
1. A double-channel impeller casting process of duplex stainless steel comprises the following steps:
1) Preparing a sand core: the sand core comprises an upper impeller sand core, a lower impeller sand core, a central core rod sand core, a first molding sand core and a second molding sand core, wherein the upper impeller sand core is formed by processing a first molding core shell, the lower impeller sand core is formed by processing a second molding core shell, the upper impeller sand core and the lower impeller sand core are made of resin sand, chromite sand is sprayed into the first molding core shell and the second molding core shell during processing of the upper impeller sand core and the lower impeller sand core, and then the resin sand is filled into the first molding core shell and the second molding core shell, so that the outer sides of the upper impeller sand core and the lower impeller sand core form chromite sand outer surfaces;
the central core rod sand core is formed by processing a third forming core shell;
the first molding sand core and the second molding sand core are processed by adopting a fourth molding core shell, and the first molding sand core and the second molding sand core are made of chromite sand;
the first molding sand cores and the second molding sand cores are assembled in grooves of the upper impeller sand cores and the lower impeller sand cores, the central core rod sand cores are inserted into central holes of the lower impeller sand cores, and the upper impeller sand cores and the lower impeller sand cores are spliced into an integral sand core;
2) And (3) manufacturing an outer mold: processing an outer mold according to the appearance of the product;
3) Casting: firstly placing an outer mold in a sand box, wherein the sand box comprises an upper box and a lower box, a first riser is arranged at the position of the upper box, which is positioned at the shaft hole of a double-flow-passage impeller, a second riser is arranged at the joint part of a port ring and a blade at the upper side of the double-flow-passage impeller, a third riser is arranged at the joint part of the port ring and the blade at the lower side of the double-flow-passage impeller, and the sizes of the first riser, the second riser and the third riser are 2-2.5 times of that of a hot joint at the corresponding part;
forming an outer mold sand mold in the sand box by the outer mold, then setting the whole sand core into the outer mold sand mold, and finally injecting molten steel into the sand mold through a pouring system for casting molding;
4) Unpacking and shakeout: and opening the sand box, shakeout, and taking out the molded casting.
2. The dual phase stainless steel dual flow impeller casting process of claim 1, wherein: the integral sand core is positioned at the contact part of molten steel, and is pre-coated with three times of alcohol-based zircon powder coating.
3. The dual phase stainless steel dual flow impeller casting process of claim 1, wherein: the first riser, the second riser and the third riser are all heating risers, and the heating risers are made by adding thermite, fluxing agent, oxidant and heat insulation materials during riser manufacturing.
4. The dual phase stainless steel dual flow impeller casting process of claim 1, wherein: and an external chill is arranged at the position of the lower box body between the third riser heads.
5. The dual phase stainless steel dual flow impeller casting process of claim 1, wherein: and removing the first riser, the second riser and the third riser after the box opening and the shakeout are completed.
6. The dual phase stainless steel dual flow impeller casting process according to claim 5, wherein: before the first riser, the second riser and the third riser are removed, homogenization heat treatment is needed, and after the first riser, the second riser and the third riser are removed, solution heat treatment is needed.
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| CN1326646C (en) * | 2005-12-13 | 2007-07-18 | 遵义拓特铸锻有限公司 | Vacuum pump impeller integral casting process |
| CN101920312B (en) * | 2010-08-21 | 2012-03-21 | 宜昌船舶柴油机有限公司 | Casting method and leveling tool for large multi-blade casting |
| CN203281803U (en) * | 2013-05-10 | 2013-11-13 | 天津达祥精密工业有限公司 | Core box of double-channel entire sand core |
| CN107309405B (en) * | 2017-06-06 | 2018-12-21 | 洛阳双瑞特种装备有限公司 | A kind of casting method of super-duplex stainless steel 5A material impeller |
| CN107695303A (en) * | 2017-10-13 | 2018-02-16 | 襄阳五二五泵业有限公司 | A kind of super-duplex stainless steel desulfurization pump pump housing casting technique |
| CN112387958B (en) * | 2020-11-18 | 2022-07-29 | 遵义拓特铸锻有限公司 | Manufacturing method of super duplex stainless steel single-stage double-suction centrifugal pump shell |
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Denomination of invention: A casting process for dual channel impellers made of duplex stainless steel Granted publication date: 20230714 Pledgee: Bank of China Wuxi Binhu sub branch Pledgor: Wuxi Lingtong New Material Co.,Ltd. Registration number: Y2024980028063 |