KR950003572B1 - Oscillation precision casting of brick production mold - Google Patents

Abstract

The casting method improves formability and drawability of vibrating cement brick molds by using lost wax, shell casting and injection forming. The method comprises; (A) coating the fabricated and rinsed mold made by lost wax and shell casting process with zircon sands and chamotte sands; (B) dewaxing; (C) making a precision casting mold by plastic deformation; and (D) injecting high Cr-Mo steel into the mold.

Description

Precision casting molding method of vibrating cement brick manufacturing mold

The present invention relates to a method of precision casting molding of a vibrating cement brick manufacturing mold, and more specifically, 10 coating operations using zircon sand and chamotte sand as main materials on the surface of a mold made of wax. After the mold is manufactured by inserting and heating the coated mold into the mold, a molten high chromium molybdenum steel is injected into the casting mold to inject the brick mold to mold the vibrating cement to improve processability and durability. The present invention relates to a method for precision casting of a brick manufacturing mold.

The brick manufacturing mold mainly used at present uses cast iron mainly and manufactures the brick manufacturing mold by the usual casting method, but the brick manufacturing mold of the cast iron is relatively low in strength and friction, and decarburization occurs in the product, resulting in durability. Like other types of products that are degraded and manufactured by the method of general casting, there is a problem of low surface uniformity.

On the other hand, high chromium molybdenum steel, that is, steel with chromium and molybdenum, is easily quenched and hardly quenched. Cold work is very difficult, but hot work is possible, and bending and elongation are bad. It has a resistance of up to 100 times, and chromium forms an anti-oxidation film so that no rust is generated and decarburization is hardly generated.

Accordingly, an object of the present invention is to provide a precision casting molding method of a vibrating cement brick manufacturing mold with economical efficiency by improving workability and durability.

In order to achieve the above object, in the present invention, a chrome is formed by forming a brick manufacturing mold using high chromium molybdenum steel as a raw material while using a lost wax method and a shell molding method, thereby oxidizing iron. By preventing and preventing decarburization due to heat, it was possible to manufacture a vibrating cement brick mold having improved durability, good surface roughness, and clean surface.

The present invention will be described in more detail as follows.

First, the mold used in the present invention is manufactured by a method consisting of injection, assembly, cleaning, coating, dewaxing, and firing steps.

In other words, wax (HW-150WAX) is injected into a mold made of metal to make the same model as the product, and then a plurality of models injected into the mold are assembled into a mold.

To remove chemicals or impurities on the surface of the assembled mold, immerse the washing solution (saline), dry it, and coat about 10 times.

Binders used for coating (BINDER) are divided into primary and backup (Backup), the primary binder is used only for the first coating is used for the backup binder from the second to the last coating.

The primary binder is a mixture of 350 mesh zircon flour mixed with a colloidal silica solution and stirred to a proper viscosity. will be.

In addition, sand is required for coating, and zircon sand for primary coating, chamotte sand No. 5 for secondary coating, chamotte sand No. 4 for tertiary coating, and fourth to fifth. Chaco sand sand No. 3 is used for the tea coating, and chamo sand sand no. 2 is used for the 6th to 9th coatings. The final coating is dipped in a backing binder without sanding and dried.

After each coating step, the coating is dried for 4 hours or more at room temperature with a relative humidity of 40% after the previous step is completed, and then the coating is performed in the next step.

After the coating was completed by the above-described method and the handles attached to the mold were removed, the mold was placed in an airtight steamer, water vapor was infused to melt the wax, and the mold was heated to a temperature of about 1000 ° C. By firing, the mold for precision casting is completed.

The materials used in the manufacture of precision casting molds are preferably those having excellent fire resistance that can maintain their properties even at about 1800 ℃, especially zircon powder is effective in Australia, Africa.

Meanwhile, the molten metal injected into the mold mold is charged with 89-90% of stainless steel scrap in an induction furnace, and a high frequency is generated to make the solid as a liquid, followed by 7-9% of high chromium steel and 0.5 molybdenum steel. -1.5% is added and induction heating is carried out to completely liquefy all the inputs, and then 0.2-0.5% of manganese steel and 0.3-0.7% of silicon steel are liquefied and ladle is a device that can transfer the molten metal to the mold mold. Prepare.

A small amount of aluminum is added to the prepared ladle, the molten metal is tilted, the ladle is received, and then injected into the mold mold.

As described above, the mold for forming the vibrating cement brick of the present invention is formed by inserting the above-mentioned molten metal into the precision casting mold and casting the mold.

High chromium molybdenum steel, the raw material for the vibrating cement brick mold of the present invention, has 1.3-1.7% of carbon (C), 1.0-1.4% of silicon (Si), 0.6-1.0% of manganese (Mn), and chromium. (Cr) is 20-22%, molybdenum (Mo) is 0.5-0.8%, phosphorus (P) is 0.04% or less, sulfur (S) is 0.04% or less, and the rest is iron (Fe) for strength, friction It is preferable in view of characteristics such as resistance, appearance and rust occurrence.

The vibrating cement brick manufacturing mold manufactured by the method of the present invention has a very beautiful surface, excellent strength and resistance to friction, and does not become aging erosion such as chromium forming an anti-oxidation film so that no rust occurs. Since heat resistance is improved, decarburization is hardly generated even at a high temperature as compared with a mold made of iron, so that a phenomenon of strength decrease due to heat does not occur.

The following examples more specifically describe the precise casting molding method of the mold for producing a vibrating cement brick of the present invention, but are not intended to limit the scope of the present invention.

Example 1

89.8 kg of stainless steel (sus430) scrap is charged into an electric furnace (induction melting furnace) of 100 kg x 150 kw, and heated by oscillating high frequency.

When heated to 30 minutes and raised to 1300 ℃, stainless steel is gradually melted from solid to liquid.In this case, 8kg of high chromium steel and 1kg of molybdenum steel are added and induction heating is performed for about 20 minutes to rise to 1700 ℃ -1750 ℃. After completely liquefied, add 0.2 kg of manganese steel and 0.5 kg of silicon steel, and after about 1 minute, put 0.5 kg of aluminum into the prepared ladle and tilt the molten metal.

At this time, the temperature of the molten metal is about 1750 ℃-1780 ℃, after receiving the molten metal by tilting the molten metal, injecting the molten metal into the mold mold prepared by the above method, and then cooled and demolded by the vibrating cement brick of the present invention A manufacturing mold was prepared.

The mold mold was prepared according to the following method.

In other words, using wax (HW-150WAX), it is injected into a mold made of metal to make the same model as the product, and several models are assembled into a bundle to form a mold, which is then washed with a washing solution (usually using brine). Dip, take out and dry, then coat 10 times.

The primary coating is performed by mixing and stirring 70% 350 mesh zircon powder in a 25% colloidal silica solution by weight to a primary binder adjusted in viscosity, and coating 5% zircon sand, and the secondary coating is applied to the primary binder. Use about 30% mixed colloidal silica solution, apply Chamotte Sand No. 5, and from the 3rd coating to the 10th coating, add 280 mesh zircon powder to the secondary binder 35% -65% according to the extinction state. Use a backing binder, but apply Chamo Sand Sand No. 4 in the 3rd coating, Chamo Sand Sand No. 3 in the 4th to 5th coatings, and Chamo Sand Sand No. 2 in the 6th to 9th coatings, and do not coat sand after the 10th coating. Coating.

Between each coating step is dried for 4 hours under conditions of room temperature, relative humidity 40%.

After removing the handle from the mold to complete the coating was put into a steamer and injecting steam to perform a waxing process, and was prepared by firing for 3 hours to 1000 ℃ in a firing furnace made of refractory brick.

The brick molding mold manufactured by the method of the present invention and the brick molding mold manufactured by the conventional method were molded to form bricks, and as a result of the economics and the durability, the product of the present invention was found to be much superior.

In other words, the product of the invention can be used to manufacture bricks up to 65-75 days of operation, while the conventional products can be used only about 28-34 days, the production cost per unit of the invention is expensive, but the overall economical efficiency and durability Significantly improved.

Claims (2)

After 10 coatings are applied to the injected, assembled and cleaned molds using conventional Lost Wax and Shell casting methods, the molds are subjected to the normal dewaxing and firing steps to form the precision casting molds. Elemental Molecules: Carbon (C): 1.3-1.7%, Silicon (Si): 1.0-1.4%, Manganese (Mn): 0.6-1.0%, Chromium (Cr): 20-22%, Molybdenum (Mo) , 0.5-0.8%, phosphorus (P): 0.04% or less, sulfur (S): 0.04% or less, molten steel of high chromium molybdenum steel (73% -75%) is injected into the precision casting mold and cast Precision casting molding method of vibrating cement brick manufacturing mold, characterized in that. The method of claim 1, wherein the coating is performed 10 times, but the primary coating is a binder for primary coating using a 350 mesh zircon powder mixed with a colloidal silica solution in the state of zircon sand coated, the secondary coating is 1 Use a colloidal silica solution mixed with a primary binder, and apply Chamotte Sand No. 5. For the third to tenth coatings, use a backing binder in which 280 mesh zircon powder is added to the secondary coating binder. Silver chamotte sand No. 4, 4th to 5th coatings are Chamotte sand No. 3, 6th to 9th coatings are coated with Chamotte sand No. 2, and the 10th coating is immersed in a backup binder without sanding and then removed. Precision casting molding method of vibrating cement brick manufacturing mold, characterized by drying for 4 hours at room temperature of about 40%.