CN110640091A - Steel structure sand core, steel structure sand core manufacturing method and bolt hole casting method - Google Patents
Steel structure sand core, steel structure sand core manufacturing method and bolt hole casting method Download PDFInfo
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- CN110640091A CN110640091A CN201911021263.XA CN201911021263A CN110640091A CN 110640091 A CN110640091 A CN 110640091A CN 201911021263 A CN201911021263 A CN 201911021263A CN 110640091 A CN110640091 A CN 110640091A
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- 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
- B22C9/101—Permanent cores
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- 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
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- 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
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- 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
- B22C9/108—Installation of cores
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- 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
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Abstract
The invention belongs to the technical field of casting, and particularly relates to a steel structure sand core, a manufacturing method of the steel structure sand core and a bolt hole casting method. The steel structure sand core comprises a sand core body shell, a molding sand filling body and an exhaust hole; the manufacturing method of the steel structure sand core adopts steel pipe welding, sand filling and drying to complete the manufacturing of the finished steel structure sand core; the bolt hole casting method adopts the finished product steel structure sand core to complete the casting and forming of the bolt hole. The steel structure sand core provided by the invention has the characteristics of simple process, convenience in operation, low manufacturing difficulty and convenience in manufacturing, can improve the casting quality when used for casting the bolt hole, can shorten the construction period, ensures the position precision of the bolt hole, reduces the later grinding workload of the bolt hole, improves the surface quality and the internal quality of the casting, improves the production efficiency of the casting and shortens the construction period.
Description
Technical Field
The invention belongs to the technical field of casting, and particularly relates to a steel structure sand core, a manufacturing method of the steel structure sand core and a bolt hole casting method.
Background
In the casting industry, the blast furnace brick-inlaid cooling wall made of nodular cast iron is mostly made into a casting mold by hand molding with molding sand which takes quartz sand as a main raw material. The bolt hole of the blast furnace brick-inlaid cooling wall is obtained by casting a casting by using a clay sand core in a casting mould and then cleaning the casting. The upper part of the clay sand core is cylindrical, and the lower part of the clay sand core is cuboid; the clay sand core is made by manually pounding clay core sand and a core bone special for the sand core into a wooden core box. The clay sand core is fixed and positioned and exhausted by adopting a single lower core head, and the refractory mortar is pressed on the upper end surface of the clay sand core for fixing. After the secondary drying of the casting mould and the primary drying of the clay sand core, the clay sand core is put into the casting mould body, a certain inclination angle is also arranged on part of the clay sand core, the clay sand core is fixed and positioned according to the size and the process requirements, and then the mould is checked and closed.
Because of the different capacities of the blast furnace and the different layers of the cooling walls, the wall thickness of the brick-inlaid cooling wall of the blast furnace is different, the required heights of the sand cores of the bolt holes are different, and the heights of the sand cores of the bolt holes are about 350mm to 1200 mm. The clay sand core is easy to have uneven hardness in the manual pounding process, so the long sand core is difficult to pout, the time consumption is long, and the clay sand core is easy to bend and deform in the core opening box, the storage and the drying processes. And moreover, the surrounding of the clay sand core is wrapped by the metal liquid, the environment is severe, and the conditions of fleshiness, sand adhesion, unevenness, hole shape deformation and the like in the bolt hole are easy to occur due to the erosion of the metal liquid and the influence of liquid shrinkage and solid shrinkage, so that the cleaning and polishing difficulty in the bolt hole is caused, the permeability of the bolt hole is seriously influenced, and the mounting bolt cannot penetrate normally. Moreover, the lower core head is not fixed and positioned firmly, the defects of clay sand core deflection, metal liquid drilling exhaust passages, excessive meat on the upper parts of bolt holes and the like are easily generated in the box closing process, the quality and the production progress of the blast furnace brick-inlaid cooling wall are seriously influenced, the manufacturing difficulty and the workload of operators in the early stage are increased, and the difficulties are brought to the cleaning and polishing processes in the later stage.
Disclosure of Invention
In order to solve the problems, the invention provides a steel structure sand core, a manufacturing method of the steel structure sand core and a bolt hole casting method, and the technical scheme is as follows:
a steel structure sand core comprises a sand core body shell, a molding sand filling body and exhaust holes; the sand core body comprises a sand core body shell, a sand core body and a sand core body, wherein the upper part of the sand core body shell is a cylindrical cavity, the lower part of the sand core body shell is a rectangular cavity, the cylindrical cavity is communicated with the rectangular cavity, and the lower end of the cylindrical cavity is connected with the upper end of the rectangular cavity through a connecting plate; the sand core body shell is filled with the molding sand filling body; the top of the molding sand filling body is provided with the exhaust hole.
The steel structure sand core as described above is more preferably: the device also comprises an upper core print shell and a lower core print shell; the upper core head shell is connected with the upper end face of the cylindrical cavity; the lower core head shell is connected with the lower end face of the cuboid cavity; the upper core head shell, the lower core head shell and the sand core body shell are all steel structural parts.
The steel structure sand core as described above is more preferably: the length of the upper core print shell is 35mm to 45mm, and the length of the lower core print shell is 45mm to 55 mm.
The steel structure sand core as described above is more preferably: the molding sand filling body comprises an upper wet molding sand layer, a middle dry molding sand layer and a lower wet molding sand layer which are sequentially connected from top to bottom; the interface of the upper wet type sand layer and the middle dry type sand layer is positioned below the joint surface of the upper core head shell and the cylindrical cavity; the interface of the lower wet molding sand layer and the middle dry molding sand layer is positioned above the junction of the lower core head shell and the cuboid cavity body.
The steel structure sand core as described above is more preferably: the upper wet molding sand layer and the lower wet molding sand layer are both clay sand, the clay sand comprises quartz sand, clay and water, the silica content of the quartz sand is more than ninety percent, and the granularity is 70-100 meshes.
The steel structure sand core as described above is more preferably: the thickness of the upper wet molding sand layer is 20mm to 30mm greater than the length of the upper core print shell; the thickness of the lower wet molding sand layer is 20mm to 30mm greater than the length of the lower core print shell; the length of the vent hole is the same as that of the upper wet type sand layer, and the diameter of the vent hole is 4mm to 6 mm.
The steel structure sand core as described above is more preferably: the anti-carburizing sand core is characterized by further comprising an anti-carburizing coating layer, wherein the anti-carburizing coating layer covers the outer wall of the sand core body shell.
The steel structure sand core as described above is more preferably: the sand-sticking prevention coating layer covers the inner wall of the sand core body shell.
A manufacturing method of a steel structure sand core comprises the following steps:
the method comprises the following steps: welding and manufacturing a sand core body shell;
step two: welding an upper core head shell on the top of the sand core body shell and welding a lower core head shell on the bottom of the sand core body shell;
step three: coating anti-carburizing coating layers on the outer walls of the upper core head shell, the sand core body shell and the lower core head shell, and coating anti-sticking sand coating layers on the inner walls;
step four: inverting the sand core body shell, sequentially filling an upper wet type sand layer, a middle dry type sand layer and a lower wet type sand layer, pounding the upper wet type sand layer and the lower wet type sand layer, and then pricking out exhaust holes on the upper wet type sand layer to manufacture a semi-finished steel structure sand core;
step five: and drying the semi-finished product steel structure sand core to prepare a finished product steel structure sand core.
The method for manufacturing a sand core as described above is more preferably: in the first step, a full-welding mode is adopted, and circular pipes, square pipes and connecting plates with the same wall thickness are welded into the sand core body shell with a cylindrical cavity and a rectangular cavity.
The method for manufacturing a sand core as described above is more preferably: and in the second step, the coaxial connection between the sand core body shell and the upper core head shell and the coaxial connection between the sand core body shell and the lower core head shell are realized in a spot welding mode.
The method for manufacturing a sand core as described above is more preferably: in the fourth step, the upper wet type sand layer is filled and then pounded; filling the medium-dry molding sand layer, wherein the medium-dry molding sand layer adopts 200-mesh dry sand; and filling the lower wet type sand layer and pounding the lower wet type sand layer.
The method for manufacturing a sand core as described above is more preferably: and step five, vertically placing the semi-finished steel structure sand core into a drying kiln for drying.
A bolt hole casting method for cast molding of a bolt hole in a cooling wall of a blast furnace, comprising the steps of:
the method comprises the following steps: placing the finished steel structure sand core into a lower core head casting mold of a lower casting mold of a cooling wall of a blast furnace, and aligning the lower end of the shell of the sand core body with the lower surface of the lower core head casting mold;
step two: inserting a thin iron rod from the upper surface of an upper core head casting mould of an upper casting mould of a blast furnace cooling wall until the thin iron rod is inserted into the exhaust hole;
step three: descending the upper blast furnace cooling wall casting mould, and enabling the sand core body shell to enter an upper core head casting mould of the upper blast furnace cooling wall casting mould until the upper blast furnace cooling wall casting mould and the lower blast furnace cooling wall casting mould are closed, and the upper end of the sand core body shell is flush with the upper surface of the upper core head casting mould;
step four: filling water glass self-hardening sand into the intersection of the upper surface of the upper casting mold of the blast furnace cooling wall and the thin iron rod, compacting, and drawing out the thin iron rod after compacting;
step five: and casting the cooling wall of the blast furnace, and detaching the upper core head shell, the lower core head shell, the upper wet type sand layer, the middle dry type sand layer and the lower wet type sand layer after opening the box to finish casting the bolt holes.
The bolt hole casting method as described above is more preferably: the bolt holes and the cooling wall of the blast furnace are cast and molded in a box-type casting mode, and after the bolt holes are cast, the upper end faces of the bolt holes and the lower end faces of the bolt holes are polished.
Analysis shows that compared with the prior art, the invention has the advantages and beneficial effects that:
1. the steel structure sand core is a steel structure, and when the steel structure sand core is used, the steel structure sand core is integrally placed in a casting mold of a casting, so that the effect of internal chill can be achieved, and the quality of the casting is improved; the influence of uneven hardness of the molding sand filling body is small when the casting sand is pounded manually, the casting sand cannot be bent and deformed when the casting sand is pounded manually, stored and dried, and the casting sand is simple and convenient to manufacture; when a casting is cast, the steel structure sand core is integrally placed between the lower casting mold and the upper casting mold of the casting, so that bidirectional positioning can be performed, positioning is firm, and deflection is not easy to occur; after the casting of the casting is finished, the shell of the sand core body is integrated with the casting, so that the problems of fleshiness, sand adhesion, unevenness, hole pattern deformation and the like in a bolt hole can be solved; the method has the advantages that the upper end face and the lower end face of the bolt hole only need to be polished in the later stage, polishing procedures are simple, workload is low, the smooth and transparent bolt hole can be obtained without polishing in the hole, the method has the characteristic of convenience in manufacturing, casting quality of castings can be improved, and the method also has the characteristics of short construction period, accurate and firm positioning and low later-stage polishing workload when in use.
2. The manufacturing method of the steel structure sand core has the advantages of simple process, convenient operation and low manufacturing difficulty, can avoid the bending deformation of the sand core, has short pounding length, and can avoid the influence of uneven pounding hardness on the sand core.
3. The bolt hole casting method adopts the steel structure sand core to realize the forming of the bolt hole, and the steel structure sand core can play a role of internal chill during casting, so that the structure of the blast furnace cooling wall near the bolt hole is more compact, the surface quality and the internal quality of the blast furnace cooling wall can be improved, the production efficiency of the blast furnace cooling wall is improved, and the construction period is shortened.
Drawings
Fig. 1 is a top view of the steel structural sand core of the present invention.
Fig. 2 is a cross-sectional view of the steel structural sand core of the present invention.
Fig. 3 is a partial enlarged view of the present invention at B in fig. 2.
Fig. 4 is a schematic view showing the installation of the steel core of the present invention in the casting of a cooling wall of a blast furnace.
In the figure: 1-a sand core body shell; 2-mounting the core head shell; 3-lower core head shell; 4-cylindrical cavity; 5-a cuboid cavity; 6-wet molding sand layer is coated; 7-medium dry sand layer; 8-exhaust hole; 9-anti-carburizing coating layer; 10-anti-sticking sand coating layer; 11-lower wet sand layer; 12-a connecting plate; 13-casting on the cooling wall of the blast furnace; 14-blast furnace stave lower casting mould.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are for convenience of description of the present invention only and do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. The terms "connected" and "connected" used herein should be interpreted broadly, and may include, for example, a fixed connection or a detachable connection; they may be directly connected or indirectly connected through intermediate members, and specific meanings of the above terms will be understood by those skilled in the art as appropriate.
Referring to fig. 1 to 4, fig. 1 is a top view of the steel core of the present invention; FIG. 2 is a cross-sectional view of the steel structural sand core of the present invention; FIG. 3 is an enlarged view of a portion of the present invention at B of FIG. 2; fig. 4 is a schematic view showing the installation of the steel core of the present invention in the casting of a cooling wall of a blast furnace. In fig. 2 and 3, the dots between the upper core housing 2 and the cylindrical cavity 4 represent spot welding; dots between the cuboid cavity 5 and the lower core head housing 3 represent spot welding; the triangle and trapezoid among the cylindrical cavity 4, the connecting plate 12 and the cuboid cavity 5 represent full welding.
As shown in fig. 1 and 2, the invention provides a steel structure sand core, which mainly comprises a sand core body shell 1, a molding sand filling body and an exhaust hole 8; the upper part of the sand core body shell 1 is a cylindrical cavity 4, the lower part of the sand core body shell is a rectangular cavity 5, and the cylindrical cavity 4 is communicated with the rectangular cavity 5; the sand core body shell 1 is filled with a molding sand filling body; the top of the molding sand filling body is provided with an exhaust hole 8. The lower end of the cylindrical cavity 4 is connected with the upper end of the cuboid cavity 5 through a connecting plate 12, the connecting plate 12 is of a hollow structure with an inner circle and an outer square, namely the inner circle of the connecting plate 12 is connected with the lower end of the cylindrical cavity 4, and the diameter of the inner circle of the connecting plate 12 is consistent with the outer diameter of the lower end of the cylindrical cavity 4; the outer rectangle of the connecting plate 12 is connected with the upper end of the cuboid cavity 5, and the side length of the outer rectangle of the connecting plate 12 is consistent with that of the upper end of the cuboid cavity 5. The material of the connecting plate 12 is preferably steel plate, the thickness of the steel plate is preferably 4mm, and the strength of the 4mm steel plate can meet the use requirement of the invention.
Specifically, the sand core body shell 1 of the steel structure sand core comprises a cylindrical cavity 4 and a rectangular cavity 5 which are communicated, the sand core body shell 1 is a steel structural part made of a round pipe, a square pipe and a connecting plate 12, a molding sand filling body is filled in the sand core body shell 1, and the sand core body shell 1 and the molding sand filling body are placed into a casting mold of a casting together when in use, so that the sand core body shell and the molding sand filling body can play a role of internal chill, the structure of the casting around a bolt hole is more compact, and the quality of the casting is improved; the steel structure sand core is slightly influenced by the uneven hardness of the molding sand filling body during manual pounding, does not bend and deform during manual pounding, storage and drying, and is simple and convenient to manufacture; when a box type casting (such as a blast furnace cooling wall) is adopted, the steel structure sand core is integrally placed between the lower casting mold and the upper casting mold, when the upper casting mold and the lower casting mold are closed, the lower end surface of the sand core body shell 1 is positioned below the lower core head casting lower surface of the lower casting mold, and the upper end surface of the sand core body shell 1 is positioned above the upper core head casting upper surface of the upper casting mold, so that two-way positioning can be carried out by depending on two ends of the steel structure sand core, the positioning is firm, and deflection is not easy to occur; after casting of the casting is finished, the sand core body shell 1 is integrated with the casting, an internal cavity of the sand core body shell 1 can be used as a bolt hole after the molding sand filling body is removed, and the problems of fleshiness, sand sticking, unevenness, hole pattern deformation and the like in the bolt hole can be solved; when the bolt hole is ground in the later period, only the upper end surface and the lower end surface of the bolt hole (namely the part of the sand core body shell 1 which is higher than the upper surface of the upper core head casting mould and the part of the sand core body shell 1 which is lower than the lower surface of the lower core head casting mould) are ground, the upper end surface and the lower end surface of the bolt hole are smooth and clean, the grinding process is simple, the workload is low, and the smooth and transparent bolt hole can be obtained without grinding in the hole, so that the steel structure sand core has the characteristic of convenience in manufacturing, can improve the casting quality of a casting, and has the characteristics of short construction period, accurate and firm positioning and low later grinding workload when in use.
As an improvement of the present invention, as shown in fig. 1 to 4, the present invention further provides the following modifications:
in order to reduce the workload of the later grinding of the bolt holes, as shown in fig. 2, the steel structure sand core further comprises an upper core head shell 2 and a lower core head shell 3; the upper core head shell 2 is connected with the upper end surface of the cylindrical cavity 4; the lower core print shell 3 is connected with the lower end surface of the cuboid cavity 5; the upper core head shell 2, the lower core head shell 3 and the sand core body shell 1 are all steel structural members; the length of the upper core print shell 2 is 35mm to 45mm, the length of the lower core print shell 3 is 45mm to 55mm, and the upper core print shell 2 and the lower core print shell 3 are both filled with green sand. The upper core head shell 2 is made of a steel round pipe with the same wall thickness (for example, the wall thickness is 4mm) as that of the cylindrical cavity 4 and the same diameter; the lower core head shell 3 of the invention is made of a steel square tube with the same wall thickness (for example, the wall thickness is 4mm) and the same section shape as the cuboid cavity 5, the upper core head shell 2 and the cylindrical cavity 4 are coaxially spot-welded (the axis of the upper core head shell 2 and the cylindrical cavity 4 are coincident, the connection is realized by adopting the spot welding mode on the connection surface) when the connection is carried out, the lower core head shell 3 and the cuboid cavity 5 are coaxially spot-welded (the lower core head shell 3 and the surface of the cuboid cavity 5 at the connection part are completely coincident, the connection surface is realized by adopting the spot welding mode), when the upper casting mold and the lower casting mold of the casting are closed, the lower end surface of the sand core body shell 1 is flush with the lower surface of the lower core head casting mold of the lower casting mold, the upper end surface of the sand core body shell 1 is flush with the upper surface of the upper core head casting mold of the casting, after the casting is finished, the lower core head shell 3 falls off, the upper end surface and the lower end surface of the bolt hole are smooth and clean, so that the grinding workload at two ends of the bolt hole can be reduced, the upper core head shell 2 and the lower core head shell 3 can be repeatedly utilized, and the consumption of steel is reduced, so that the steel structure sand core has the characteristics of small grinding workload and less material consumption when in use.
In order to facilitate the separation of the sand filling body from the sand core body shell 1 after the casting of the casting is finished, as shown in fig. 2, the sand filling body of the steel structure sand core comprises an upper green sand layer 6, a middle dry sand layer 7 and a lower green sand layer 11 which are sequentially connected from top to bottom, the interface of the upper green sand layer 6 and the middle dry sand layer 7 is positioned below the joint surface of the upper core head shell 2 and the cylindrical cavity 4, and the interface of the lower green sand layer 11 and the middle dry sand layer 7 is positioned above the joint surface of the lower core head shell 3 and the rectangular cavity 5, so that the situation that the casting is polluted by the sand of the middle dry sand layer 7 flowing out of the gap at the joint of the upper core head shell 2 and the sand core body shell 1 and the gap at the joint of the lower core head shell 3 and the sand core body shell 1 can be avoided. According to the invention, the upper wet sand layer 6 and the lower wet sand layer 11 are adopted to plug the middle dry sand layer 7, the plugging length of the upper wet sand layer 6 is the length (35mm to 45mm) of the upper core head shell 2 plus 20mm to 30mm (located in the sand core body shell 1), the plugging length of the lower wet sand layer 11 is the length (45mm to 55mm) of the lower core head shell 3 plus 20mm to 30mm (located in the sand core body shell 1), and the dry sand of the middle dry sand layer 7 can be effectively prevented from scattering into a casting. After the foundry goods casting is accomplished, adopt the sledgehammer to hit gently and can realize the first shell of upper core 2, the first shell of lower core 3 drops, the first shell of upper core 2 and the most part type sand of the first shell of lower core 3 that drops have taken away the molding sand in the first shell of upper core 2 and the first shell of lower core 3 (the most part type sand of the first sand layer of upper green sand 6 and the wet sand layer 11 down), only leave the molding sand of the less part type sand layer of upper green sand 6 and the wet sand layer 11 down in psammitolite body shell 1, only need to tear off the less part type sand of the first sand layer of upper green sand 6 and the less part type sand of the wet sand layer 11 down and can let the molding sand of well dry molding sand layer 7 flow out, the sand core obturator of being convenient for breaks away from body shell 1, the inner chamber is smooth, it is penetrating, the terminal surface levels up only need slightly the coping can.
Further, as shown in the figure, the thickness of the upper wet sand layer 6 of the steel structure sand core is 20mm to 30mm larger than the length of the upper core head shell 2, and the thickness of the lower wet sand layer 11 is 20mm to 30mm larger than the length of the lower core head shell 3, preferably, clay sand is selected for the upper wet sand layer 6 and the lower wet sand layer 11, the clay sand comprises quartz sand, clay and water, the content of silica in the quartz sand is more than ninety percent, the granularity is 70 meshes to 100 meshes, the middle dry sand layer 7 can be effectively plugged, and the middle dry sand layer 7 is made of 200 meshes of quartz sand; the length of exhaust hole 8 is the same with the length of last wet type sand bed 6, and the diameter of exhaust hole 8 is 4mm to 6mm, and the steel construction psammitolite of being convenient for exhausts.
In order to avoid the reduction of the mechanical properties of the sand core body shell 1, as shown in fig. 3, the steel structure sand core of the present invention further comprises an anti-carburizing coating layer 9, and the anti-carburizing coating layer 9 covers the outer wall of the sand core body shell 1. The anti-carburizing coating layer 9 can prevent carbon in the molten metal from permeating into the sand core body shell 1 during casting, so that the increase of the carbon content in the sand core body shell 1 can be avoided, the problems of mechanical property reduction, easy cracking, easy deformation and the like caused by the increase of the carbon content in the sand core body shell 1 are prevented, and the service life of the sand core body shell 1 is prolonged.
Further, the anti-carburizing coating layer 9 is preferably a KC-202 anti-carburizing coating which is mentioned in 3 rd stage of 1993 in journal named as Benzhu technology and mainly comprises alumina, dichromium trioxide, silicon dioxide, silicon carbide, bentonite, sodium silicate, liquid lithium silicate and the like.
In order to reduce the adhesion between the molding sand of the medium dry type sand layer 7 and the sand core body shell 1, as shown in fig. 3, the steel structure sand core of the invention further comprises an anti-sticking sand coating layer 10, and the anti-sticking sand coating layer 10 covers the inner wall of the sand core body shell 1, so that the adhesion between the molding sand of the medium dry type sand layer 7 and the sand core body shell 1 can be reduced, and the separation of a molding sand filling body from the sand core body shell 1 is further facilitated.
Further, the sand adhesion preventing coating layer 10 is preferably a crystalline flake graphite alcohol-based casting coating which is mainly prepared by grinding and mixing crystalline flake graphite, water and clay.
As shown in fig. 1 to 4, the invention also provides a manufacturing method of the steel structure sand core, which comprises the following steps:
the method comprises the following steps: and (4) welding to manufacture the sand core body shell 1.
Wherein, the mode that adopts the full weld uses the pipe of the same wall thickness, square pipe and connecting plate 12 weld into the psammitolite body shell 1 that has cylinder type cavity 4 and cuboid type cavity 5, psammitolite body shell 1 is steel, at the seam crossing that pipe and connecting plate 12 are connected, the seam crossing that connecting plate 12 and square union coupling all adopt the mode welding of full weld, all seams all adopt the welding seam to cover, with the pipe, connecting plate 12, square pipe welding formula integrated into one piece, can avoid when the casting in the molding sand obturator gets into the foundry goods, preferably, the pipe, square pipe, the thickness of connecting plate 12 is 4 mm.
Step two: and welding the upper core head shell 2 at the top of the sand core body shell 1, and welding the lower core head shell 3 at the bottom of the sand core body shell 1.
Wherein, adopt spot welding's mode to realize the coaxial coupling of psammitolite body shell 1 and last core head shell 2, the coaxial coupling of psammitolite body shell 1 and lower core head shell 3. The upper core head shell 2 adopts a circular tube with the same wall thickness and diameter as the cylindrical cavity 4; the lower core print shell 3 adopts a square tube with the same wall thickness and sectional area as the cuboid cavity 5. During welding, the axis of the cylindrical cavity 4 is coincided with the axis of the upper core head shell 2, the central axis of the cuboid cavity 5 is coincided with the central axis of the lower core head shell 3, and four sides are coincided. Adopt the mode of spot welding to carry out welded fastening, can guarantee to go up core head shell 2 and be connected of psammitolite body shell 1, core head shell 3 all has certain joint strength with being connected of psammitolite body shell 1 down, and the later stage of also being convenient for when renovating goes up core head shell 2, drops of core head shell 3 down.
Step three: and an anti-carburizing coating layer 9 is coated on the outer walls of the upper core print shell 2, the sand core body shell 1 and the lower core print shell 3, and an anti-sticking sand coating layer 10 is coated on the inner wall.
Wherein, the anti-carburizing coating layer 9 adopts KC-202 anti-carburizing coating; the anti-sand coating layer 10 is made of a crystalline flake graphite alcohol-based casting coating.
Step four: invert psammitolite body shell 1, fill in proper order and go up wet sand bed 6, well dry sand bed 7 and wet sand bed 11 down, pound and prick out exhaust hole 8 on last wet sand bed 6 behind actual wet sand bed 6 and the wet sand bed 11 down, make semi-manufactured steel structure psammitolite.
Wherein, the upper wet type sand layer 6 is pounded after the upper wet type sand layer 6 is filled; then filling the medium dry sand layer 7; then filling the lower wet type sand layer 11 and pounding the lower wet type sand layer 11. The middle dry sand layer 7 adopts dry sand of 200 meshes, and the thickness of the upper wet sand layer 6 is 20mm to 30mm larger than the length of the upper core head shell 2; the thickness of the lower wet sand layer 11 is 20mm to 30mm greater than the length of the lower core head shell 3; the length of the vent hole 8 is the same as that of the upper wet type sand layer 6, and the diameter of the vent hole 8 is 4mm to 6 mm. Namely, the upper end and the lower end of the sand core body shell 1 are plugged by green sand, the plugging length is 20mm to 30mm and is respectively added with the length of the upper core head shell 2 and the length of the lower core head shell 3, and dry sand of the middle dry sand layer 7 can be prevented from scattering into a casting.
Step five: and drying the semi-finished steel structure sand core to obtain the finished steel structure sand core.
The semi-finished steel structure sand core is vertically placed into a drying kiln for drying, and dry sand in the steel structure sand core can be prevented from leaking out by the aid of the vertical placement mode.
In conclusion, the manufacturing method of the steel structure sand core has the advantages of simple process, convenience in operation and low manufacturing difficulty, can avoid bending deformation of the sand core, is short in pounding length, and can avoid the influence of uneven pounding hardness on the sand core.
As shown in fig. 1 to 4, the present invention also provides a bolt hole casting method for cast molding of a bolt hole in a cooling wall of a blast furnace, including the steps of:
the method comprises the following steps: and (3) placing the finished steel structure sand core into a lower core head casting mold of a lower casting mold 14 of a blast furnace cooling wall, and aligning the lower end of the sand core body shell 1 with the lower surface of the lower core head casting mold.
Wherein, lower core head shell 3 is located the below of lower core head casting mould, can play the supporting position effect.
Step two: the thin iron rod is inserted from the upper surface of the upper core head of the upper casting mold 13 of the blast furnace cooling wall until the thin iron rod is inserted into the exhaust hole 8.
The fine iron rod is inserted into the exhaust hole 8 from the upper surface of the upper core head casting mold of the upper blast furnace cooling wall casting mold 13, the positioning position of the steel structure sand core in the lower core head casting mold of the lower blast furnace cooling wall casting mold 14 can be finely adjusted, and the upper core head shell 2 can enter the upper core head casting mold to be positioned and fixed more accurately when the upper blast furnace cooling wall casting mold 13 and the lower blast furnace cooling wall casting mold 14 are combined.
Step three: and (3) descending the upper casting mould 13 of the cooling wall of the blast furnace, and enabling the sand core body shell 1 to enter the upper core head casting mould of the upper casting mould 13 of the cooling wall of the blast furnace until the upper casting mould 13 of the cooling wall of the blast furnace and the lower casting mould 14 of the cooling wall of the blast furnace are closed, and the upper end of the sand core body shell 1 is flush with the upper surface of the upper core head casting mould.
The upper core head shell 2 is located above the upper core head casting mold, can play a role in supporting and positioning, and can form bidirectional positioning by being matched with the supporting and positioning of the lower core head shell 3, so that the mounting and positioning accuracy of the steel structure sand core is ensured.
Step four: and filling water glass self-hardening sand into the intersection of the upper surface of the upper casting 13 on the cooling wall of the blast furnace and the thin iron rod, compacting, and drawing out the thin iron rod after compacting.
The water glass self-hardening sand is hardened according to the principles that the water glass self-hardening sand is hardened by heating and has strong adhesive force, so that the fixing and positioning effects on the steel structure sand core can be realized, and the steel structure sand core is prevented from floating in molten metal; after the iron rod is drawn out, the exhaust holes 8 can guide and exhaust the gas generated in the steel structure sand core to the outside of the upper casting mold 13 of the blast furnace cooling wall.
Step five: and (3) casting the cooling wall of the blast furnace, and detaching the upper core head shell 2, the lower core head shell 3, the upper wet type sand layer 6, the middle dry type sand layer 7 and the lower wet type sand layer 11 after opening the box to finish casting the bolt holes.
When the upper core head shell 2 and the lower core head shell 3 are detached, the upper core head shell 2 and the lower core head shell 3 can be detached only by lightly striking with a sledge hammer because the upper core head shell 2 and the sand core body shell 1 are connected in a spot welding mode and the lower core head shell 3 and the sand core body shell 1 are connected in a spot welding mode, and the detached upper core head shell 2 and the detached lower core head shell 3 can be recycled.
When the bolt hole casting method is implemented, the bolt hole and the blast furnace cooling wall are cast and molded in a box type casting mode, and after the bolt hole is cast, the bolt hole with a smooth and transparent inner cavity can be obtained only by grinding the upper end face of the bolt hole and the lower end face of the bolt hole, so that the cost and the workload of later cleaning and grinding are reduced.
In conclusion, the bolt hole casting method disclosed by the invention realizes the forming of the bolt hole by adopting the steel structure sand core, and the steel structure sand core can play a role of internal chill during casting, so that the structure of the blast furnace cooling wall near the bolt hole is more compact, the upper surface and the lower surface of the cooling wall are smooth and clean, the cost and the workload of later cleaning and polishing are greatly reduced, the manufacturing difficulty of the sand core is reduced, the surface quality and the internal quality of the blast furnace cooling wall can be improved, the production efficiency of the blast furnace cooling wall is improved, and the construction period is shortened.
It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.
Claims (10)
1. A steel structure sand core, comprising:
the sand core comprises a sand core body shell, a molding sand filling body and an exhaust hole;
the sand core body comprises a sand core body shell, a sand core body and a sand core body, wherein the upper part of the sand core body shell is a cylindrical cavity, the lower part of the sand core body shell is a rectangular cavity, the cylindrical cavity is communicated with the rectangular cavity, and the lower end of the cylindrical cavity is connected with the upper end of the rectangular cavity through a connecting plate; the sand core body shell is filled with the molding sand filling body; the top of the molding sand filling body is provided with the exhaust hole.
2. The steel structural sand core of claim 1, further comprising:
an upper core head shell and a lower core head shell;
the upper core head shell is connected with the upper end face of the cylindrical cavity; the lower core head shell is connected with the lower end face of the cuboid cavity; the upper core head shell, the lower core head shell and the sand core body shell are all steel structural parts.
3. The steel structure sand core of claim 2, wherein:
the molding sand filling body comprises an upper wet molding sand layer, a middle dry molding sand layer and a lower wet molding sand layer which are sequentially connected from top to bottom;
the interface of the upper wet type sand layer and the middle dry type sand layer is positioned below the joint surface of the upper core head shell and the cylindrical cavity; the interface of the lower wet molding sand layer and the middle dry molding sand layer is positioned above the junction of the lower core head shell and the cuboid cavity body.
4. The steel structure sand core of claim 3, wherein:
the thickness of the upper wet molding sand layer is 20mm to 30mm greater than the length of the upper core print shell; the thickness of the lower wet molding sand layer is 20mm to 30mm greater than the length of the lower core print shell; the length of the vent hole is the same as that of the upper wet type sand layer, and the diameter of the vent hole is 4mm to 6 mm.
5. The steel structural sand core of claim 1 or 2, further comprising:
and the anti-carburizing coating layer covers the outer wall of the sand core body shell.
6. The steel structural sand core of claim 1 or 2, further comprising:
and the sand sticking prevention coating layer covers the inner wall of the sand core body shell.
7. The manufacturing method of the steel structure sand core is characterized by comprising the following steps of:
the method comprises the following steps: welding and manufacturing a sand core body shell;
step two: welding an upper core head shell on the top of the sand core body shell and welding a lower core head shell on the bottom of the sand core body shell;
step three: coating anti-carburizing coating layers on the outer walls of the upper core head shell, the sand core body shell and the lower core head shell, and coating anti-sticking sand coating layers on the inner walls;
step four: inverting the sand core body shell, sequentially filling an upper wet type sand layer, a middle dry type sand layer and a lower wet type sand layer, pounding the upper wet type sand layer and the lower wet type sand layer, and then pricking out exhaust holes on the upper wet type sand layer to manufacture a semi-finished steel structure sand core;
step five: and drying the semi-finished product steel structure sand core to prepare a finished product steel structure sand core.
8. The method of making a sand core of claim 7, wherein:
in the first step, a full-welding mode is adopted, and circular pipes, square pipes and connecting plates with the same wall thickness are welded into the sand core body shell with a cylindrical cavity and a rectangular cavity;
in the second step, the coaxial connection between the sand core body shell and the upper core head shell and the coaxial connection between the sand core body shell and the lower core head shell are realized in a spot welding mode;
in the fourth step, the upper wet type sand layer is filled and then pounded; filling the medium-dry molding sand layer, wherein the medium-dry molding sand layer adopts 200-mesh dry sand; filling the lower wet type sand layer and pounding the lower wet type sand layer;
and step five, vertically placing the semi-finished steel structure sand core into a drying kiln for drying.
9. A bolt hole casting method for cast molding of a bolt hole in a cooling wall of a blast furnace, characterized by comprising the steps of:
the method comprises the following steps: placing the finished steel structure sand core of any one of claims 7 to 8 into a lower core head mold of a blast furnace stave lower mold, aligning the lower end of the sand core body shell with the lower surface of the lower core head mold;
step two: inserting a thin iron rod from the upper surface of an upper core head casting mould of an upper casting mould of a blast furnace cooling wall until the thin iron rod is inserted into the exhaust hole;
step three: descending the upper blast furnace cooling wall casting mould, and enabling the sand core body shell to enter an upper core head casting mould of the upper blast furnace cooling wall casting mould until the upper blast furnace cooling wall casting mould and the lower blast furnace cooling wall casting mould are closed, and the upper end of the sand core body shell is flush with the upper surface of the upper core head casting mould;
step four: filling water glass self-hardening sand into the intersection of the upper surface of the upper casting mold of the blast furnace cooling wall and the thin iron rod, compacting, and drawing out the thin iron rod after compacting;
step five: and casting the cooling wall of the blast furnace, and detaching the upper core head shell, the lower core head shell, the upper wet type sand layer, the middle dry type sand layer and the lower wet type sand layer after opening the box to finish casting the bolt holes.
10. The method of casting a bolt hole according to claim 9, characterized in that:
the bolt holes and the cooling wall of the blast furnace are cast and molded in a box-type casting mode, and after the bolt holes are cast, the upper end faces of the bolt holes and the lower end faces of the bolt holes are polished.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911021263.XA CN110640091A (en) | 2019-10-25 | 2019-10-25 | Steel structure sand core, steel structure sand core manufacturing method and bolt hole casting method |
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| CN201911021263.XA CN110640091A (en) | 2019-10-25 | 2019-10-25 | Steel structure sand core, steel structure sand core manufacturing method and bolt hole casting method |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111673050A (en) * | 2020-05-19 | 2020-09-18 | 中国科学院金属研究所 | Method for filling hollow ceramic core for precision investment casting |
| CN113414354A (en) * | 2021-05-28 | 2021-09-21 | 四川共享铸造有限公司 | Method for preventing copper pipe from being melted through |
-
2019
- 2019-10-25 CN CN201911021263.XA patent/CN110640091A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111673050A (en) * | 2020-05-19 | 2020-09-18 | 中国科学院金属研究所 | Method for filling hollow ceramic core for precision investment casting |
| CN113414354A (en) * | 2021-05-28 | 2021-09-21 | 四川共享铸造有限公司 | Method for preventing copper pipe from being melted through |
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