Sand mold combined type casting device for steel columnar crystal standard sample and manufacturing method

Abstract

The invention relates to a sand mold combined casting device for a steel columnar crystal standard sample and a manufacturing method, the sand mold combined casting device comprises a front box frame and a rear box frame which are detachably and fixedly connected, the rear box frame and the front box frame are filled with sand mold filler, a front graphite plate and a front copper plate which are attached to each other are arranged in the front box frame, and a rear graphite plate and a rear copper plate which are attached to each other are arranged in the rear box frame. The side, away from the front graphite plate, of the front copper plate is fixedly connected with a plurality of front copper columns, and the side, away from the front copper plate, of the front graphite plate is attached to the butt joint face of the rear box frame and the front box frame. A rear graphite plate and a rear copper plate which are attached to each other are arranged in the rear box frame, a plurality of rear copper columns are fixedly connected to the side, away from the rear graphite plate, of the rear copper plate, a cast plate forming cavity is formed between the rear graphite plate and the front graphite plate, and a pouring channel communicated to the lower end of the cast plate forming cavity and a riser channel communicated to the upper end of the cast plate forming cavity are formed in the rear box frame. The device is simple in structure, easy to manufacture, low in cost, convenient to use, time-saving, labor-saving and good in cooling effect, and the obtained steel standard sample casting plate can be made into a steel standard sample for spectrum detection only through linear cutting.

Description

Technical Field

[0001] This invention relates to the field of metallurgical testing technology, specifically to a sand mold combined casting device and manufacturing method for steel columnar crystal standard samples. Background Technology

[0002] As a quantitative detection method, spectral detection has been widely used in the inspection of production processes in the metallurgical and casting industries. Before spectral detection, it is necessary to prepare standard samples for spectral detection of the corresponding steel grades before spectral analysis can be performed on the samples.

[0003] The preparation methods for standard samples for spectral detection are as follows: 1. Preparation of standard samples for spectral detection by hot deformation of forging and rolling: The shape of the ingot is changed by hot deformation such as forging or rolling, and the uniformity of the structure is improved to obtain standard sample blocks; 2. Obtaining standard sample blocks by casting: Common practical applications mainly involve cast steel materials, cast iron materials that cannot be deformed by hot working, and newly developed steel grades; high manganese steel types such as ZG120Mn13 and ZG120Mn18; cast iron materials such as wear-resistant white cast iron, RMTCr16, RMTCr26, and chilled white cast iron for rolling mills. Spectral detection standard samples for materials similar to the above are all manufactured by casting.

[0004] There are currently no unified standards or equipment for preparing steel standard blocks by casting. In order to obtain dense columnar crystals or even single columnar crystal structures, the cooling rate during solidification can only be increased. Generally, steel molds, iron molds, or copper molds are used for direct cooling, or even water is passed through the steel molds, copper molds, or iron molds to accelerate cooling.

[0005] Wuhan Iron and Steel (Group) Corporation filed an invention patent application on November 11, 2014, entitled "Steel Production Process and Casting Device for Spectroscopic Standards," patent application number CN201410629856.5. This invention utilizes a medium-frequency furnace for smelting and a horizontal casting device for ingot casting, suitable for large-scale production of alloy element standards. The rapid cooling process of the steel ingot significantly reduces component segregation in the steel, solving two major technical challenges: component control and component segregation in up to 20 element standards. The invention describes the use of a combined iron mold with an inner diameter of 200mm and a length / diameter ratio >3 as a cooling mold. During casting, the ingot is cast at an angle, and the resulting ingot is used for spectral detection. The device employs a steel mold for cooling.

[0006] Shanxi Baiyi Machinery Equipment Manufacturing Co., Ltd. filed a Chinese invention patent application on July 16, 2011, entitled "Manufacturing Method of Standard Samples for Spectroscopic Analysis of Nickel-Containing Pig Iron" (patent number CN201110198929.6). The method for cooling the standard samples involves processing a copper rod into a standard sample mold, using a steel plate as the mold base, and connecting the mold to the base plate using a welding process. A carbon steel water tank is used for overall cooling. Water is introduced into the bottom water tank 3 seconds after pouring begins, and the water supply is shut off 10 minutes after pouring is completed. The tank is then kept warm for 1 hour before being opened. However, the method has several drawbacks. Firstly, water circulation through the steel mold before pouring is insufficient to preheat the mold cavity and remove moisture. Secondly, even after 10 minutes of water supply interruption after pouring, the hot water vapor inside the tank still vaporizes, increasing internal pressure and posing safety risks. Therefore, a separate circulating water system and pressurization device are needed for precise control. Furthermore, the top-pouring, rain-type spectral standard sample pouring system has low self-slag removal capacity and lacks dedicated feeding risers to improve the casting quality of the standard samples.

[0007] Shanxi Taigang Stainless Steel Co., Ltd. filed an invention patent application on July 28, 2011, entitled "A Method for Preparing Spectral Standard Samples" (patent application number CN201110220348.8). The application proposes a continuous casting tundish casting method for standard sample preparation, using refractory bricks and ceramic tubes as sample molds. Molten steel from the tundish is directly poured into the molds to prepare steel ingots with a length of 500mm and a diameter of 43mm. After removing the head and tail, the ingots are directly processed into standard samples with a diameter of 40mm and a length of 40mm. This process is suitable for steel grades produced through continuous casting, but it is not feasible for researching new steel grades. Using refractory materials as molds results in a significantly lower solidification rate compared to iron or steel molds, leading to slower solidification in the center. Furthermore, the length-to-diameter ratio of the steel ingot is greater than 11, making it difficult to ensure a dense central structure, resulting in large detection deviations in the center of the standard sample.

[0008] The shortcomings of existing casting methods for preparing spectral standards of steel are as follows: 1. Waterless steel molds and iron molds require appropriate preheating to prevent moisture from affecting the quality of the ingots, but preheating the molds reduces the cooling rate during solidification; 2. Applying appropriate coatings to improve demolding properties increases solidification impurities and thermal resistance, reducing the cooling rate; 3. Using combined molds requires machining and running-in of mating surfaces, and gaps between molds allow molten steel to seep in, making demolding difficult; 4. While water circulation in the mold can improve cooling capacity, it results in low casting cavity temperature before pouring and the cavity being prone to moisture; if a pressurization device is added to increase cooling water, adjusting the water flow and pressure during pouring requires accumulated practical experience to better control cooling performance, demanding high operational skills and affecting the stability of spectral standard preparation; 5. Using steel molds, copper molds, and water-cooled molds results in relatively simple mold structures, but they are heavy and difficult to move. Summary of the Invention

[0009] To address the shortcomings of existing technologies, this invention provides a sand mold combined casting device and manufacturing method for steel columnar crystal standards. The device has a simple structure, is easy to manufacture, has low cost, and good cooling effect. The resulting steel standard casting plate can be made into steel standards for spectral detection by wire cutting.

[0010] This invention is achieved through the following technical solution: a sand mold combined casting device for steel columnar crystal specimens is provided, including a detachably fixed front box frame and a rear box frame. The rear box frame and the front box frame are filled with sand mold filler. The front box frame is provided with a front graphite plate and a front copper plate that are attached to each other. Multiple front copper columns are fixed to the side of the front copper plate away from the front graphite plate. The side of the front graphite plate away from the front copper plate is attached to the mating surface of the rear box frame and the front box frame. The rear box frame is provided with a rear graphite plate and a rear copper plate that are attached to each other. Multiple rear copper columns are fixed to the side of the rear copper plate away from the rear graphite plate. A casting plate forming cavity is formed between the rear graphite plate and the front graphite plate. The rear box frame is provided with a pouring channel connecting to the lower end of the casting plate forming cavity and a riser channel connecting to the upper end of the casting plate forming cavity.

[0011] As an optimization, the front copper pillars are perpendicular to the front copper plate and multiple front copper pillars are arranged in a rectangular array; the rear copper pillars are perpendicular to the rear copper plate and multiple rear copper plates are arranged in a rectangular array.

[0012] As an optimization, sand-shaped packing extends from the ends of both the front and rear copper pillars.

[0013] As an optimization, the rear graphite plate and the front graphite plate are parallel.

[0014] As an optimization, front box fixing blocks are fixedly connected to the two opposite outer side walls of the front box frame, and rear box fixing blocks are fixedly connected to the two opposite outer side walls of the rear box frame. The front box fixing blocks and the rear box fixing blocks are connected by bolts.

[0015] As an optimization, the upper end of the rear box frame is provided with a pouring through hole, and the pouring channel includes a pouring cup, a vertical ceramic tube, a horizontal ceramic tube and a plurality of ceramic branch pipes connected in sequence in the pouring through hole, and the upper end of the ceramic branch pipes is connected to the casting plate forming cavity.

[0016] As an optimization, the riser channel includes a riser through hole opened at the upper end of the rear box frame, and the sand mold packing has a riser cavity that connects the riser through hole and the casting plate forming cavity.

[0017] A method for manufacturing a steel standard casting plate includes the following steps: a. Assemble the front box frame and the rear box frame. During assembly, place the casting plate model at the casting plate forming cavity position, place the riser model at the riser channel position, and sprinkle parting sand on the mating surface of the rear box frame and the front box frame. b. Separate the front box frame and the rear box frame, remove the riser model and the casting plate model, remove the parting sand, and then assemble the front box frame and the rear box frame. c. Slowly pour the molten steel or iron from the ladle into the casting channel. After casting is completed, spray water on the front and rear boxes to cool the front and rear copper pillars. After cooling is complete, the molded casting plate can be opened and taken out.

[0018] As an optimization, before pouring, air at 100-120°C is introduced to purge the casting cavity and pouring channel to remove moisture and impurities. Then, 5-10 minutes before pouring, preheated argon gas is introduced into the casting cavity and pouring channel to reduce secondary oxidation of molten steel or iron during the pouring process.

[0019] As an optimization, the method for preparing molten steel or iron in the ladle is as follows: After the molten steel or iron has settled in the smelting furnace, pour the molten steel or iron from the smelting furnace into the ladle, then pour the molten steel or iron from the ladle back into the smelting furnace, raise the temperature to 100-150°C above the melting point, repeat the operation 2-3 times, and finally pour it into the ladle.

[0020] The beneficial effects of the present invention are as follows: the sand mold combination casting device and manufacturing method for steel columnar crystal standard of the present invention has a simple structure, is easy to manufacture, has low cost, is convenient to use, saves time and effort, has a good cooling effect, and the steel standard casting plate obtained can be made into steel standard for making spectral detection by wire cutting. Attached Figure Description

[0021] Figure 1 This is a front view schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the structure of the present invention from the left. Figure 3 This is a top view of the structure of the present invention; Figure 4 This is a top view of the rear box frame structure of the present invention; Figure 5 For the present invention Figure 3 A sectional view of plane C-C; Figure 6 This is a schematic diagram of the outer side of the rear box frame of the present invention; Figure 7 For the present invention Figure 6 Sectional view of plane A-A; Figure 8 This is a schematic diagram of the inner side of the rear box frame of the present invention; Figure 9 This is a schematic diagram of the inner side of the front box frame of the present invention; Figure 10 For the present invention Figure 9 Sectional view of plane B-B; Figure 11 This is a front view of the riser model of the present invention; Figure 12 This is a side view of the riser model of the present invention; Figure 13 A schematic diagram of the steel columnar crystal standard sample prepared according to the present invention; Figure 14 A physical image of the steel columnar crystal standard sample prepared for this invention; As shown in the figure: 1. Rear box frame; 101. Rear box handle; 102. Rear box fixing block; 103. Sprue through hole; 104. Riser through hole; 2. Front box frame; 201. Front box handle; 202. Front box fixing block; 3. Sprue cup; 4. Vertical ceramic tube; 5. Horizontal ceramic tube; 6. Ceramic branch pipe; 7. Rear copper plate; 8. Rear copper column; 9. Riser model; 10. Rear graphite plate; 11. Casting plate model; 12. Front copper plate; 13. Front copper column; 14. Front graphite plate; 15. Casting plate forming cavity; 16. Riser cavity. Detailed Implementation

[0022] To clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0023] Example 1: like Figures 1-14 As shown, the present invention provides a sand mold combined casting device for steel columnar crystal specimens, comprising a detachably fixed front box frame 2 and a rear box frame 1. The rear box frame 1 and the front box frame 2 are filled with sand mold filler. The front box frame 2 and the rear box frame 1 are both rectangular frames with the same external dimensions. The rear box frame 1 and the front box frame 2 are joined together at the mating surface.

[0024] The sand mold filler is composed of molten ceramsite, alkaline phenolic binder and curing agent. The amount of alkaline phenolic binder added is 1.5-2.2% of the total weight of the sand mold filler. The mass ratio of alkaline phenolic binder to curing agent is 10:1. The particle size of the molten ceramsite is 40-70 mesh, the sand intake is not less than 100 mm, and the compressive strength of the sand mold is 1.5-2.0 MPa.

[0025] Front box fixing blocks 202 are fixedly connected to the two opposite outer side walls of the front box frame 2, and rear box fixing blocks 102 are fixedly connected to the two opposite outer side walls of the rear box frame 1. The front box fixing blocks 202 and the rear box fixing blocks 102 correspond to each other and are connected by bolts so that the rear box frame 1 and the front box frame 2 are connected and fixed as a whole.

[0026] Rear box handles 101 are fixedly connected to the two opposite outer side walls of the rear box frame 1, and front box handles 201 are fixedly connected to the two opposite outer side walls of the front box frame 2, respectively, for transporting the rear box frame 1 and the front box frame 2.

[0027] like Figure 5 As shown, the front box frame 2 is provided with a front graphite plate 14 and a front copper plate 12 that are attached to each other. The side of the front graphite plate 14 away from the front copper plate 12 is attached to the mating surface of the rear box frame 1 and the front box frame 2.

[0028] Multiple front copper pillars 13 are fixed to the side of the front copper plate 12 away from the front graphite plate 14. The front copper pillars 13 are perpendicular to the front copper plate 12 and are arranged in a rectangular array. Sand-shaped filler extends from the ends of the front copper pillars 13 to increase heat dissipation and improve cooling effect.

[0029] like Figure 5 As shown, the rear frame 1 contains a rear graphite plate 10 and a rear copper plate 7 that fit together. Multiple rear copper columns 8 are fixed to the side of the rear copper plate 7 away from the rear graphite plate 10. The rear copper columns 8 are perpendicular to the rear copper plate 7, and the multiple rear copper plates 7 are arranged in a rectangular array. Sand-shaped fillers extend from the ends of the rear copper columns 8, thereby increasing heat dissipation and improving cooling performance.

[0030] The rear graphite plate 10 and the front graphite plate 14 are parallel. A casting plate forming cavity 15 is formed between the rear graphite plate and the front graphite plate 14, and the cast plate is formed in the casting plate forming cavity 15.

[0031] The rear frame 1 is provided with a casting channel that connects to the lower end of the casting plate forming cavity 15. The upper end of the rear frame 1 has a pouring through hole 103. The casting channel includes a pouring cup 3, a vertical ceramic tube 4, a horizontal ceramic tube 5, and multiple ceramic branch pipes 6 connected sequentially in the pouring through hole 103. The upper end of the ceramic branch pipes 6 is connected to the casting plate forming cavity 15. The upper end of the pouring cup 3 is connected to the pouring through hole 103, the upper end of the vertical ceramic tube 4 is connected to the lower end of the pouring cup 3, one end of the horizontal ceramic tube 5 is connected to the lower end of the vertical ceramic tube 4, and the lower end of the ceramic branch pipes 6 is connected to the horizontal ceramic tube 5. In this embodiment, there are three ceramic branch pipes 6, which are evenly distributed at the bottom of the casting plate forming cavity 15.

[0032] Molding sand filler is provided in the cavity of the rear box frame 1 outside the pouring cup 3, vertical ceramic tube 4, horizontal ceramic tube 5, ceramic branch tube 6, rear copper plate 7, rear graphite plate 10, casting plate forming cavity 15 and riser cavity 16.

[0033] The rear frame 1 is provided with a riser channel connecting to the upper end of the casting plate forming cavity 15. The riser channel includes a riser through-hole 104 located at the upper end of the rear frame 1, above the casting plate forming cavity 15. The sand mold packing has a riser cavity 16 connecting the riser through-hole 104 and the casting plate forming cavity 15. The riser cavity 16 is connected to the casting plate forming cavity 15, and the front side of the riser cavity 16, the front side of the casting plate forming cavity 15, and the front side of the peripheral wall of the rear frame 1 are all located in the same plane. During manufacturing, the riser cavity 16 is currently positioned at its designated location. Figure 11 ,12 The riser model 9 shown is filled with molding sand. After the riser model 9 is removed, the riser cavity 16 can be formed.

[0034] The length of the casting plate forming cavity 15 is 400-600mm, the width is 400-600mm, and the thickness is 35-60mm, which is the same as the size of the casting plate to be made; the length and width of the rear graphite plate 10, the rear copper plate 7, the front graphite plate 14, and the front copper plate 12 are the same as those of the casting plate forming cavity 15, the thickness of the rear graphite plate 10 and the front graphite plate 14 is 25-40mm, and the thickness of the rear copper plate 7 and the front copper plate 12 is 35-60mm; the diameter of the rear copper column 8 and the front copper column 13 is 25-40mm, and the spacing between adjacent rear copper columns 8 and adjacent front copper columns 13 is 30-80mm; the outer diameter of the ceramic branch pipe 6 is the same as the thickness of the casting plate forming cavity 15; the bottom surface dimension of the riser cavity 16 is the same as the top surface dimension of the casting plate forming cavity 15, and the top surface width of the riser cavity 16 is 1.5 times the bottom surface width.

[0035] During the solidification of liquid metal, the cross-section of the ingot structure is divided into equiaxed crystals at the edges, columnar crystals, and equiaxed crystals at the center. The equiaxed crystals at the edges are very thin, while the central equiaxed crystals are formed during the later stages of solidification. The central equiaxed region exhibits macroscopic compositional segregation compared to the columnar crystals, and the center, being the last to solidify, contains defects such as porosity and even shrinkage cavities. Columnar crystals, on the other hand, do not exhibit macroscopic compositional segregation during solidification. Current techniques for obtaining spectroscopic analysis results for cast standards can detect columnar crystals, equiaxed crystals, or a mixed structure. As the size of the cast sample increases, this macroscopic compositional difference becomes more pronounced, ultimately leading to decreased accuracy and increased uncertainty in the results of cast standard spectroscopic analysis. Figure 13 This is a cross-sectional schematic diagram of the cast plate made according to the present invention. The left and right ends are in contact with the front graphite plate 14 and the rear graphite plate 10, respectively. Figure 14 This is a cross-sectional view of the cast plate produced by this invention, with its left and right ends contacting the front graphite plate 14 and the rear graphite plate 10, respectively. This invention ultimately achieves a spectral detection surface perpendicular to the columnar crystals during solidification, and accelerates solidification to obtain a solidification structure with all columnar crystals. Thus, the spectral detection surface is always perpendicular to the solidified columnar crystals, significantly improving the uniformity of composition on the spectral detection surface. This invention utilizes a single, thin, integrally cooled cast plate, accelerating cooling to obtain columnar crystals on both sides. The spectral standard can then be processed into cylindrical, square, or other shapes.

[0036] A method for manufacturing a steel standard casting plate includes the following steps: a. Fabrication of the rear box body: Place the front side of the rear box frame 1 flat on the workbench, with the riser through-hole 104 of the top plate of the rear box frame 1 located below. Place the riser model 9 inside the riser through-hole 104. Place the casting plate model 11, three ceramic support pipes 6, horizontal ceramic pipes 5, vertical ceramic pipes 4, and pouring cup 3 on the workbench inside the cavity of the rear box frame 1. Insert the upper opening of the pouring cup 3 into the pouring through-hole 103 of the top plate of the rear box frame 1, so that the upper surface of the casting plate model 11 is flush with the lower surface of the riser model 9, and the upper opening of the three ceramic support pipes 6 is flush with the lower surface of the plate model 11. The three ceramic support pipes 6 are evenly distributed, and the lower ends of the three ceramic support pipes 6 are flush with the lower surface of the plate model 11. A horizontal ceramic tube 5 is connected and fixed, one end of which is connected and fixed to the lower end of a vertical ceramic tube 4, and the upper end of a vertical ceramic tube 4 is connected and fixed to the lower end of a pouring cup 3. A rear graphite plate 10 is placed on the rear plate surface of the casting plate model 11, a rear copper plate 7 is placed on the rear plate surface of the rear graphite plate 10, and rear copper columns 8 are evenly distributed on the rear plate surface of the rear copper plate 7. Molten ceramic particles, alkaline phenolic binder and curing agent are mixed evenly to form sand mold filler, and the sand mold filler is filled into the cavity of the rear box frame 1, so that the rear end face of the rear copper column 8 is exposed on the rear side of the sand mold filler in the cavity of the rear box frame 1. After the sand mold filler is cured, the rear box body is obtained.

[0037] Flip the rear box 180 degrees so that the front side of the rear box is facing upwards, with the riser model 9 and the casting plate model 11 on top. Sprinkle a layer of parting sand on the front side of the rear box.

[0038] Fabrication of the front box body: Align the rear side of the front box frame 2 with the front side of the rear box frame 1; place the front graphite plate 14 inside the cavity of the rear box frame 2 and place the front graphite plate 14 on the front plate surface of the casting plate model 11; place the front copper plate 12 on the front plate surface of the front graphite plate 14; and evenly distribute the front copper pillars 13 on the front plate surface of the front copper plate 12; mix the molten ceramic particles, alkaline phenolic binder, and curing agent evenly to form a sand mold filler, and fill the cavity of the front box frame 2 with the sand mold filler, so that the front end face of the front copper pillar 13 is exposed on the front side of the sand mold filler inside the cavity of the front box frame 2. After the sand mold filler has cured, the front box body is obtained.

[0039] Assemble the front box frame 2 and the rear box frame 1. During assembly, place the casting plate model 11 at the casting plate forming cavity 15 and the riser model 9 at the riser channel.

[0040] b. Separate the front box frame 2 and the rear box frame 1, remove the riser model 9 and the casting plate model 11, remove the parting sand, and then assemble the front box frame 2 and the rear box frame 1; make the gating through hole 103 of the rear box frame 1 face upwards, and obtain a sand mold combination casting device for steel columnar crystal standard sample.

[0041] Before pouring, air at 100-120°C is introduced to purge the casting plate forming cavity 15 and the pouring channel to remove moisture and impurities. Then, 5-10 minutes before pouring, preheated argon gas is introduced into the casting plate forming cavity 15 and the pouring channel to reduce secondary oxidation of molten steel or iron during the pouring process.

[0042] c. After the molten steel or iron has settled in the smelting furnace, pour the molten steel or iron from the smelting furnace into the ladle, then pour the molten steel or iron from the ladle back into the smelting furnace, raise the temperature to 100-150°C above the melting point, repeat the operation 2-3 times, and finally pour it into the ladle; through the above operation, the uniformity of the composition and temperature of the poured molten steel or iron is improved.

[0043] The molten steel or iron in the ladle is slowly poured into the pouring cup 3, and the casting temperature is 20-40℃ higher than the normal casting temperature. After casting, the front box and the rear box are sprayed with water to cool the front copper pillar 13 and the rear copper pillar 8, so as to shorten the opening time. After cooling, the box can be opened and the formed casting plate can be taken out.

[0044] To prepare steel standard blocks for spectral detection: the surface of the cast plate is cleaned by shot blasting, and the two sides of the cast plate are machined by grinding or milling to remove equiaxed crystals and surface defects. Then, the plate is cut to the required size by wire cutting to obtain the steel standard blocks for spectral detection.

[0045] In this embodiment 1, a sand casting device for the above-mentioned steel columnar crystal standard sample is used to produce a special A05 material casting plate for slurry pumps. The casting plate has a length of 500mm, a width of 500mm, and a thickness of 35mm, and is used to make steel standard samples for spectral detection of A05 material.

[0046] In this embodiment, the sand mold filler is composed of molten ceramsite, alkaline phenolic binder and curing agent. The amount of alkaline phenolic binder added is 1.5-2.2% of the total weight of the sand mold filler, the mass ratio of alkaline phenolic binder to curing agent is 10:1, the particle size of molten ceramsite is 40-70 mesh, the sand intake is 120 mm, and the sand mold compressive strength is 2.0 MPa.

[0047] The casting plate forming cavity 15 has a length of 500mm, a width of 500mm, and a thickness of 35mm, which is the same as the dimensions of the casting plate to be produced. The lengths and widths of the rear graphite plate 10, rear copper plate 7, front graphite plate 14, and front copper plate 12 are the same as those of the casting plate forming cavity 15. The thicknesses of the rear graphite plate 10 and front graphite plate 14 are 25mm, and the thicknesses of the rear copper plate 7 and front copper plate 12 are 50mm. The diameters of the rear copper pillars 8 and front copper pillars 13 are 30mm, and the spacing between adjacent rear copper pillars 8 and adjacent front copper pillars 13 is 80mm. The outer diameter of the ceramic branch pipe 6 is the same as the thickness of the casting plate forming cavity 15. The bottom surface dimensions of the riser cavity 16 are the same as the top surface dimensions of the casting plate forming cavity 15, and the top surface width of the riser cavity 16 is 1.5 times the bottom surface width.

[0048] Before pouring, purge the casting cavity 15 and the gating system with air at 100-120°C. Then, 5-10 minutes before pouring, introduce preheated argon gas into the casting cavity 15 and the gating system. After the molten steel or iron has settled in the furnace, pour it into the ladle, then pour it back into the furnace and heat it to 100-150°C above its melting point. Repeat this process 2-3 times, finally pouring the molten steel or iron into the ladle. Slowly pour the molten steel or iron from the ladle into the ladle. Pour the casting into the pouring cup 3, and increase the casting temperature by 20-40℃ compared to the normal casting temperature. After casting, externally spray water to cool the front and rear copper pillars 13 and 8. After cooling, the molded casting plate can be removed from the box. To make steel standard blocks for spectral detection: the surface of the casting plate is cleaned by shot blasting, and the two sides of the casting plate are machined by grinding or milling to remove equiaxed crystals and surface defects. Then, the plate is cut to the required size by wire cutting to obtain the steel standard blocks for spectral detection.

[0049] 190 standard samples with a diameter of 33 mm were prepared from each cast plate. The standard sample structure was a single columnar crystal. The two ends of the standard sample were tested. The sampling and value determination test and the uniformity test showed that the standard deviation range of the spectral standard sample met the relevant requirements of the standard material.

[0050] Example 2: In this embodiment 2, the sand casting device for the above-mentioned steel columnar crystal standard sample is used to produce an infinitely cold-hardened white cast iron roll material casting plate. The casting plate has a length of 480mm, a width of 480mm, and a thickness of 50mm, and is used to produce a steel standard sample for spectral detection of the infinitely cold-hardened white cast iron roll material.

[0051] In this embodiment, the sand mold filler is composed of molten ceramsite, alkaline phenolic binder and curing agent. The amount of alkaline phenolic binder added is 1.5-2.2% of the total weight of the sand mold filler, the mass ratio of alkaline phenolic binder to curing agent is 10:1, the particle size of molten ceramsite is 40-70 mesh, the sand intake is 120 mm, and the sand mold compressive strength is 2.0 MPa.

[0052] The casting plate forming cavity 15 has a length of 480mm, a width of 480mm, and a thickness of 50mm, which is the same as the dimensions of the casting plate to be produced. The lengths and widths of the rear graphite plate 10, rear copper plate 7, front graphite plate 14, and front copper plate 12 are the same as those of the casting plate forming cavity 15. The thicknesses of the rear graphite plate 10 and front graphite plate 14 are 30mm, and the thicknesses of the rear copper plate 7 and front copper plate 12 are 60mm. The diameters of the rear copper pillars 8 and front copper pillars 13 are 25mm, and the spacing between adjacent rear copper pillars 8 and adjacent front copper pillars 13 is 50mm. The outer diameter of the ceramic branch pipe 6 is the same as the thickness of the casting plate forming cavity 15. The bottom surface dimensions of the riser cavity 16 are the same as the top surface dimensions of the casting plate forming cavity 15, and the top surface width of the riser cavity 16 is 1.5 times the bottom surface width.

[0053] Before pouring, purge the casting cavity 15 and the gating system with air at 100-120°C. Then, 5-10 minutes before pouring, introduce preheated argon gas into the casting cavity 15 and the gating system. After the molten steel or iron has settled in the furnace, pour it into the ladle, then pour it back into the furnace and heat it to 100-150°C above its melting point. Repeat this process 2-3 times, finally pouring the molten steel or iron into the ladle. Slowly pour the molten steel or iron from the ladle into the ladle. Pour the casting into the pouring cup 3, and increase the casting temperature by 20-40℃ compared to the normal casting temperature. After casting, externally spray water to cool the front and rear copper pillars 13 and 8. After cooling, the molded casting plate can be removed from the box. To make steel standard blocks for spectral detection: the surface of the casting plate is cleaned by shot blasting, and the two sides of the casting plate are machined by grinding or milling to remove equiaxed crystals and surface defects. Then, the plate is cut to the required size by wire cutting to obtain the steel standard blocks for spectral detection.

[0054] Twelve standard samples with a diameter of 35 mm were prepared from each cast plate. The standard sample structure was a single columnar crystal. The two ends of the standard sample were tested. The sampling and value determination test and the uniformity test showed that the standard deviation range of the spectral standard sample met the relevant requirements of the standard material.

[0055] Example 3: In this embodiment 3, a low-carbon chromium-nickel-boron alloy steel casting plate is made using the sand casting device for the above-mentioned steel columnar crystal standard sample. The casting plate has a length of 450mm, a width of 450mm, and a thickness of 50mm, and is used to make steel standard samples for spectral detection of low-carbon chromium-nickel-boron alloy steel.

[0056] In this embodiment, the sand mold filler is composed of molten ceramsite, alkaline phenolic binder, and curing agent. The amount of alkaline phenolic binder added is 1.5-2.2% of the total weight of the sand mold filler, the mass ratio of alkaline phenolic binder to curing agent is 10:1, the particle size of the molten ceramsite is 40-70 mesh, the sand intake is not less than 100mm, and the compressive strength of the sand mold is 1.5-2.0MPa.

[0057] The casting plate forming cavity 15 has a length of 450mm, a width of 450mm, and a thickness of 50mm, which is the same as the dimensions of the casting plate to be produced. The lengths and widths of the rear graphite plate 10, rear copper plate 7, front graphite plate 14, and front copper plate 12 are the same as those of the casting plate forming cavity 15. The thicknesses of the rear graphite plate 10 and front graphite plate 14 are 25-40mm, and the thicknesses of the rear copper plate 7 and front copper plate 12 are 35-60mm. The diameters of the rear copper pillars 8 and front copper pillars 13 are 25-40mm, and the spacing between adjacent rear copper pillars 8 and adjacent front copper pillars 13 is 30-80mm. The outer diameter of the ceramic branch pipe 6 is the same as the thickness of the casting plate forming cavity 15. The bottom surface dimension of the riser cavity 16 is the same as the top surface dimension of the casting plate forming cavity 15, and the top surface width of the riser cavity 16 is 1.5 times the bottom surface width.

[0058] Before pouring, purge the casting cavity 15 and the gating system with air at 100-120°C. Then, 5-10 minutes before pouring, introduce preheated argon gas into the casting cavity 15 and the gating system. After the molten steel or iron has settled in the furnace, pour it into the ladle, then pour it back into the furnace and heat it to 100-150°C above its melting point. Repeat this process 2-3 times, finally pouring the molten steel or iron into the ladle. Slowly pour the molten steel or iron from the ladle into the ladle. Pour the casting into the pouring cup 3, and increase the casting temperature by 20-40℃ compared to the normal casting temperature. After casting, externally spray water to cool the front and rear copper pillars 13 and 8. After cooling, the molded casting plate can be removed from the box. To make steel standard blocks for spectral detection: the surface of the casting plate is cleaned by shot blasting, and the two sides of the casting plate are machined by grinding or milling to remove equiaxed crystals and surface defects. Then, the plate is cut to the required size by wire cutting to obtain the steel standard blocks for spectral detection.

[0059] 206 standard samples with a diameter of 36 mm were prepared from each cast plate. The standard sample structure was a single columnar crystal. The two ends of the standard sample were tested. The sampling and value determination test and the uniformity test showed that the standard deviation range of the spectral standard sample met the relevant requirements of the standard material.

[0060] Of course, the above description is not limited to the examples above. Technical features not described in this invention can be implemented by or using existing technology, and will not be repeated here. The above embodiments and drawings are only used to illustrate the technical solutions of this invention and are not intended to limit this invention. This invention has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention do not depart from the spirit of this invention and should also fall within the scope of protection of the claims of this invention.

Claims

1. A sand mold combined casting device for steel columnar crystal specimens, characterized in that: The device includes a detachably fixed front box frame (2) and a rear box frame (1). The rear box frame (1) and the front box frame (2) are filled with sand-type filler. The front box frame (2) is provided with a front graphite plate (14) and a front copper plate (12) that are attached to each other. Multiple front copper columns (13) are fixed to the side of the front copper plate (12) away from the front graphite plate (14). The side of the front graphite plate (14) away from the front copper plate (12) is attached to the rear box frame (1) and the front box frame (2). The rear box frame (1) is provided with a rear graphite plate (10) and a rear copper plate (7) that fit together. Multiple rear copper columns (8) are fixed to the side of the rear copper plate (7) away from the rear graphite plate (10). A casting plate forming cavity (15) is formed between the rear graphite plate and the front graphite plate (14). The rear box frame (1) is provided with a pouring channel that connects to the lower end of the casting plate forming cavity (15) and a riser channel that connects to the upper end of the casting plate forming cavity (15).

2. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: The front copper pillar (13) is perpendicular to the front copper plate (12) and a rectangular array of multiple front copper pillars (13) is arranged; the rear copper pillar (8) is perpendicular to the rear copper plate (7) and a rectangular array of multiple rear copper plates (7) is arranged.

3. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: Sand-shaped filler extends from the ends of the front copper column (13) and the rear copper column (8).

4. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: The rear graphite plate (10) and the front graphite plate (14) are parallel.

5. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: Front box fixing blocks (202) are fixed to the two opposite outer side walls of the front box frame (2), and rear box fixing blocks (102) are fixed to the two opposite outer side walls of the rear box frame (1). The front box fixing blocks (202) and the rear box fixing blocks (102) are connected by bolts.

6. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: The upper end of the rear box frame (1) has a pouring through hole (103). The pouring channel includes a pouring cup (3), a vertical ceramic tube (4), a horizontal ceramic tube (5) and a plurality of ceramic branch pipes (6) connected in sequence in the pouring through hole (103). The upper end of the ceramic branch pipe (6) is connected to the casting plate forming cavity (15).

7. The sand mold combined casting device for steel columnar crystal specimens according to claim 1, characterized in that: The riser channel includes a riser through hole (104) opened at the upper end of the rear box frame (1), and the sand mold packing has a riser cavity (16) that connects the riser through hole (104) and the casting plate forming cavity (15).

8. A method for manufacturing a steel standard casting plate, using the sand mold combined casting apparatus as described in any one of claims 1-7, characterized in that, Includes the following steps: a. Assemble the front box frame (2) and the rear box frame (1). During assembly, place the casting plate model (11) at the casting plate forming cavity (15), place the riser model (9) at the riser channel, and sprinkle molding sand on the mating surface of the rear box frame (1) and the front box frame (2). b. Separate the front box frame (2) and the rear box frame (1), remove the riser model (9) and the casting plate model (11), remove the parting sand, and then assemble the front box frame (2) and the rear box frame (1); c. Slowly pour the molten steel or iron from the ladle into the casting channel. After casting is completed, spray water on the front and rear boxes to cool the front copper pillar (13) and the rear copper pillar (8). After cooling is completed, the molded casting plate can be opened and taken out.

9. The method for manufacturing a steel standard casting plate according to claim 8, characterized in that: Before pouring, air at 100-120°C is introduced to purge the casting plate forming cavity (15) and pouring channel to remove moisture and impurities from the casting plate forming cavity (15) and pouring channel; then, 5-10 minutes before pouring, preheated argon gas is introduced into the casting plate forming cavity (15) and pouring channel to reduce secondary oxidation of molten steel or iron during the pouring process.

10. The method for manufacturing a steel standard casting plate according to claim 8, characterized in that: Preparation method of molten steel or iron in ladle: After the molten steel or iron has settled in the smelting furnace, pour the molten steel or iron in the smelting furnace into the ladle, then pour the molten steel or iron in the ladle back into the smelting furnace, raise the temperature to 100-150°C above the melting point, repeat the operation 2-3 times, and finally pour it into the ladle.

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