KR100977040B1 - Dies manufactured by Vertical or Horizontal Centrifugal Casting and the Method for manufactured the Same - Google Patents

Abstract

The present invention relates to a mold part such as a die by vertical or horizontal centrifugal casting and a method of manufacturing the same, in which the manufacturing cost is not only lower than the conventional technology but the life can be improved, and the structure is dense. The mold part according to the present invention, that is, the die, in weight percent, C: 0.5 to 3.0, Si: 0.1 to 2.0, Mn: 0.1 to 2.0, Cr: 10 to 25, W: 10 to 25, Fe: 1 to 5, It is achieved by a die produced by centrifugal casting, which is composed of a die layer in the form of a hollow consisting of Mo: 1 to 10, Ni: 0.1 to 5, balance Co and other unavoidable impurities. Can be.

Centrifugal casting, dies, double structure, forging

Description

Dies manufactured by Vertical or Horizontal Centrifugal Casting and the Method for manufactured the Same}

The present invention relates to a mold part by vertical or horizontal centrifugal casting and a method of manufacturing the same, and more particularly to an extrusion mold such as a die having a die layer and / or an impact-relieving layer by vertical or horizontal centrifugal casting. It relates to a hot mold and other parts such as and a method of manufacturing the same.

Generally, hot die steel, Ni alloy, Co alloy, etc. are used as the material for extrusion dies used for the extrusion process of nonferrous alloys. Extrusion die material is required to be abrasion resistance, heat resistance, corrosion resistance, fatigue resistance, etc. Among the above materials, Ni, Co alloy has the most excellent hot properties, and has a long life is superior to other materials are used most widely. The chemical composition of the Co alloy for extruded dies is shown in weight percent C: 2 to 2.5%, Cr: 30 to 35%, W: 18%, and the rest of Co and other small amounts of elements. After casting the Co alloy material of the composition is machined to make a final extrusion die product, conventional extrusion die parts made of Ni, Co alloy material lacks toughness and cracks due to impact due to heat and stress during use There is a problem that occurs. In addition, Ni, Co alloys are very expensive compared to other materials, so there are problems such as excessive manufacturing costs.

1 is a schematic diagram of a conventional die for extrusion consisting of Ni and Co alloys. Extrusion is made through the inner diameter (Ic) of the die 100, the inner diameter surface 101 is in contact with the high-temperature extruded material is subjected to a load, such as wear resistance, thermal shock. Such annular castings were mainly produced by sand casting, and since most of the tissues were gradually cooled, when viewed through a microscope, carbides became coarse and exhibit very weak characteristics such as heat and impact during extrusion.

In recent years, with the rapid rise in cost of alloyed iron and the like, in the case of a die part for an extrusion die, that is, a die, the development of alternative materials for cost reduction is urgently required as the cost of the material cost in manufacturing costs increases. However, since the addition of a certain amount of alloy to prevent a decrease in wear resistance at high temperatures is essential, it is not easy to develop alternative materials. Moreover, since die casting for extrusion dies is produced by sand casting, the size of crystal grains and carbides is relatively coarse and the structure is not dense, so that the improvement of the metal structure is absolutely required.

Accordingly, an object of the present invention is to provide a mold part such as a die by vertical or horizontal centrifugal casting and a method of manufacturing the same, which are not only cheaper in manufacturing cost but also can be improved in life compared to the prior art, and in which the structure becomes dense. have.

The above-described object is, according to one embodiment of the present invention, in weight percent C: 0.5 to 3.0, Si: 0.1 to 2.0, Mn: 0.1 to 2.0, Cr: 10 to 25, W: 10 to 25, By centrifugal casting, characterized in that it comprises a hollow die layer made of Fe: 1 to 5, Mo: 1 to 10, Ni: 0.1 to 5, residual Co, and other unavoidable impurities and produced by centrifugal casting. It can be achieved by the die produced.

Alternatively, the object as described above is also, according to another embodiment of the present invention, in weight percent C: 0.5-3.0, Si: 0.1-2.0, Mn: 0.1-2.0, Cr: 20-35, W 10 to 20, Fe to 1 to 5, Ni to 0.1 to 5, remainder Co and other unavoidable impurities, and produced by centrifugal casting, comprising a hollow die layer produced by centrifugal casting. It can be achieved by the die which becomes.

Alternatively, the object as described above is also, according to another embodiment of the present invention, in weight percent C: 0.5-3.0, Si: 0.1-2.0, Mn: 0.1-2.0, Cr: 5-20, W : 5 to 20, Fe: 1 to 5, Mo: 2 to 10, V: 0.1 to 10, Ni: 0.1 to 5, remainder Co and other unavoidable impurities, and a hollow die layer formed by centrifugal casting It can be achieved by a die produced by centrifugal casting comprising a.

Alternatively, the object as described above is also, in accordance with still another embodiment of the present invention, in weight percent C: 0.01-0.7, Si: 0.1-1.0, Mn: 0.1-2.0, Cr: 15-20, Hollow dies made of Mo: 1 to 5, Ni: 45 to 55, Nb: 2 to 7, Al: 0.1 to 2.0, Ti: 0.1 to 2.0, balance Fe, and other unavoidable impurities and produced by centrifugal casting. It can be achieved by a die produced by centrifugal casting, characterized in that it comprises a layer.

According to the present invention, a shock-absorbing layer made of a shock-absorbing material is injected, and the composition of the die layer is supplied into a hollow portion of the shock-absorbing layer at which solidification starts in a liquid state at a temperature of 1300 to 1600 ° C, thereby providing centrifugal casting. The die layer is thereby made to be bonded to the hollow portion of the impact mitigating layer.

In the above, the centrifugal casting is a horizontal or vertical centrifugal casting.

Preferably, the impact mitigating layer and / or the die layer made by centrifugal casting may be forged.

The object as described above is achieved according to another aspect of the invention by a method for producing a die comprising forming a die layer by centrifuging the composition as described above at a temperature of 1300 to 1600 ° C. Can be.

Alternatively, by injecting a shock-absorbing layer made of a shock-absorbing material, supplying the composition of the die layer into the hollow portion of the shock-absorbing layer at which the solidification starts to liquid phase at a temperature of 1300 ~ 1600 ℃ by centrifugal casting The die layer may be coupled to the hollow portion of the impact mitigating layer.

In the above, the centrifugal casting is a horizontal or vertical centrifugal casting.

Preferably, after the step of forming the impact mitigating layer or the die layer, it may further include the step of forging the impact mitigating layer or the die layer.

According to the die and die manufacturing method by vertical or horizontal centrifugal casting according to the present invention as described above, the manufacturing cost is lowered by saving 40% compared to the conventional die manufacturing cost, and the defect (bubble) in the manufactured die The incidence can be significantly reduced, the structure is dense, and the bonding ratio between the shock absorbing layer and the die layer can be increased, and the wear resistance and the impact resistance can be improved, thereby improving the service life.

As described above, since the die according to the present invention is manufactured in a hollow circle, it is manufactured by centrifugal casting as compared with the conventional sand casting, and thus has a relatively quenching effect, so that the casting structure becomes fine and dense and relatively The product excellent in heat resistance and abrasion resistance can be obtained. In addition, in the case of a die for an extrusion die, since it is disposed of only after the die layer is used to a certain depth, the die layer (inner layer) is a heat-resistant and wear-resistant material for centrifugal casting. In the case of using an inexpensive material, the manufacturing cost is low, and the shock resistance is improved, and the impact resistance can be improved.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

According to the first embodiment, the die for an extrusion die according to the present invention is, in weight%, C: 0.5 to 3.0, Si: 0.1 to 2.0, Mn: 0.1 to 2.0, Cr: 10 to 25, W: 10 to 25, Fe : 1-5, Mo: 1-10, Ni: 0.1-5, remainder Co, and the die layer (2, inner layer) which consists of other unavoidable impurities.

According to the second embodiment, the die for an extrusion die according to the present invention has the die layer 2 in weight%, C: 0.5 to 3.0, Si: 0.1 to 2.0, Mn: 0.1 to 2.0, Cr: 20 to 35, W : 10-20, Fe: 1-5, Ni: 0.1-5, remainder Co, and other unavoidable impurities.

According to the third embodiment, the die for an extrusion die according to the present invention has the die layer 2 in weight%, C: 0.5 to 3.0, Si: 0.1 to 2.0, Mn: 0.1 to 2.0, Cr: 5 to 20, W : 5-20, Fe: 1-5, Mo: 2-10, V: 0.1-10, Ni: 0.1-5, remainder Co, and other unavoidable impurities.

According to the fourth embodiment, the die for an extrusion die according to the present invention has the die layer 2 in weight%, C: 0.01 to 0.7, Si: 0.1 to 1.0, Mn: 0.1 to 2.0, Cr: 15 to 20, Mo. : 1-5, Ni: 45-55, Nb: 2-7, Al: 0.1-2.0, Ti: 0.1-2.0, remainder Fe, and other unavoidable impurities.

The die layer 2 having the composition as described above is melted at a temperature of 1300 to 1600 ° C and cast as a hollow body having a predetermined outer diameter and an inner diameter by centrifugal casting in a liquid phase. At this time, the centrifugal casting method used may be a horizontal or vertical centrifugal casting method.

In the method for producing a die as described above, first, the centrifugal mold is preheated at a predetermined temperature, and a coating agent for release purpose is spray-coated inside the centrifugal mold. As the coating agent for the release purpose, a release agent such as silica (SILICA), zirconia, and a surfactant may be selected or used in combination. While rotating the centrifugal mold at high speed, the liquid metal of the composition as described above for the liquid die layer 2 is injected into the centrifugal mold to form the die layer 2. While the material of the die layer 2 having the composition described above is closely adhered to the inner surface of the centrifugal mold by the centrifugal force with an even thickness and density, a tubular die layer 2 having a predetermined thickness is formed.

As such, the die layer 2 formed in a tubular shape may be selectively subjected to forging such as free forging, die forging, and the like. In this way, the die layer 2 formed as a die by forging molding becomes more dense in structure, and can be used as a die for an extrusion die.

On the other hand, according to the present invention, it may be formed as a double-structured die in which the impact mitigating layer 1 is provided outside the die layer 2 before the forging molding process as shown in FIG. 2. As described above, in the case where the shock absorbing layer 1 is provided outside the die layer 2, the shock absorbing material is a low-cost material such as SS400, SCM440, SNCM, SKD61, DCI or the like as the shock absorbing material by centrifugal casting as described above. The layer 1 is made into a hollow form, and after checking the temperature of the shock absorbing layer 1, the material of the die layer 2, that is, the material for heat and abrasion resistance, is melted at a temperature of 1300 to 1600 ° C. The hollow part 3 is formed in the center part of the die layer 2 by inject | pouring into the shock alleviation layer 1, and also shape | molding by centrifugal casting.

The material for the die layer 2 is a liquid phase in the molten state in the molten state into the impact mitigating layer 1 at an appropriate timing of the state before the solidification of the shock mitigating layer 1 formed into a tubular body by the centrifugal casting method as described above. Is injected into. This is because different materials are exchanged and kneaded at the interface of the contact section between the inner surface of the impact mitigating layer 1 and the outer surface of the die layer 2, thereby reducing the mutual bonding force between the impact mitigating layer 1 and the die layer 2. It is to improve.

The time point at which the material for the die layer 2 is injected into the liquid phase in the molten state is different depending on the material of the impact mitigating layer 1, but the temperature range is lower than the inherent LIQUIDUS LINE temperature of each selected material. It is preferable to inject the material for the die layer 2 in the.

The liquidus line represents the temperature at which the liquid metal begins to solidify, that is, after the outer layer forming process is completed, the material selected as the impact mitigating layer (1) slowly cools down and passes over the liquidus temperature to eventually complete solidification. It falls below the starting temperature, and the die layer 2 must be injected before the solid phase is achieved.

If inert gas or nitrogen gas is injected during this process, the joint surface and bonding strength are increased.

3 is a graph showing the relationship between the boundary distance and the hardness of the two-layer structure made according to the present invention as described above. As can be seen from FIG. 3, the hardness of the outer layer, i.e., the shock absorbing layer 1, is low, the hardness rises sharply in the boundary region with the dice layer 2, and the hardness of the inner layer, i. You can see that it increases slowly. Therefore, since the die layer 2 constituting the inner layer has a higher hardness, heat resistance and abrasion resistance can be improved, and the outer layer having a lower hardness, that is, the shock alleviation layer 1, can alleviate impact. Impact resistance can be improved.

3 is a graph showing the relationship between the boundary distance and the hardness of the two-layer structure made according to the present invention as described above. As can be seen from FIG. 3, the hardness of the inner layer, i.e., the shock absorbing layer 1 is low, and the hardness rises sharply in the boundary region with the dice layer 2, and thus the hardness of the outer layer, i. It can be seen that gradually increases. Therefore, since the die layer 2 constituting the inner layer has a higher hardness, heat resistance and abrasion resistance can be improved, and the outer layer having a lower hardness, that is, the shock alleviation layer 1, can alleviate impact. Impact resistance can be improved.

As described above, the die according to the present invention having a double structure of the shock alleviation layer 1 and the die layer 2 is selectively described as described above to compact the structure of the impact alleviating layer 1 and the die layer 2. Forging molding as such may also take place.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the invention, It is obvious that the claims fall within the scope of the claims.

1 is a schematic view of an extrusion die made of a Co alloy.

2 is a perspective view showing an extrusion die manufactured according to the casting method of the die for extrusion using a double centrifugal casting method according to an embodiment of the present invention.

3 is a graph showing the relationship between the boundary distance and the hardness of the two-layer structure made according to the present invention as described above.

Explanation of symbols on the main parts of the drawings

1: Shock Mitigating Layer 2: Dice Layer

3: hollow part

Claims (11)

By weight%, C: 0.5-3.0, Si: 0.1-2.0, Mn: 0.1-2.0, Cr: 10-25, W: 10-25, Fe: 1-5, Mo: 1-10, Ni: 0.1- 5, a die made by centrifugal casting, comprising a remainder Co and other unavoidable impurities, and comprising a die layer in a hollow form produced by centrifugal casting. By weight%, C: 0.5-3.0, Si: 0.1-2.0, Mn: 0.1-2.0, Cr: 20-35, W: 10-20, Fe: 1-5, Ni: 0.1-5, balance Co and others A die produced by centrifugal casting, which is made of an unavoidable impurity, and is made of a die layer in a hollow form produced by centrifugal casting. By weight%, C: 0.5-3.0, Si: 0.1-2.0, Mn: 0.1-2.0, Cr: 5-20, W: 5-20, Fe: 1-5, Mo: 2-10, V: 0.1- 10, Ni: 0.1-5, remainder Co, and other dies produced by centrifugal casting, characterized in that it consists of a hollow die layer formed by centrifugal casting. delete The die-cutting layer according to any one of claims 1 to 3, wherein the die-layer is injected into a hollow portion of the shock-absorbing layer in which a shock-absorbing layer made of a shock-absorbing material is injected and solidification starts in the liquid phase at a temperature of 1300-1600 占 폚. A die produced by centrifugal casting, wherein the die layer is made to bond to the hollow portion of the impact mitigating layer by supplying a composition. The die produced by centrifugal casting according to any one of claims 1 to 3, wherein the centrifugal casting is horizontal or vertical centrifugal casting. 6. The die produced by centrifugal casting according to claim 5, wherein the impact mitigating layer or the die layer made by centrifugal casting is forged. A method for producing a die, comprising the step of forming a die layer by centrifugally casting the composition as claimed in claim 1 at a temperature of 1300 to 1600 ° C. 10. The centrifugal casting process according to claim 8, wherein a shock-absorbing layer made of a shock-absorbing material is injected and the composition of the die layer is supplied into the hollow portion of the shock-absorbing layer at which solidification starts in the liquid phase at a temperature of 1300-1600 占 폚. And the die layer is bonded to the hollow portion of the impact mitigating layer. 9. The method of claim 8, wherein the centrifugal casting is horizontal or vertical centrifugal casting. 10. The method of claim 9, further comprising, after forming the impact mitigating layer or the die layer, forging the impact mitigating layer or the dice layer.

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