KR20040088952A - Manufacturing Method Of High-Cr casting - Google Patents

Abstract

PURPOSE: A method is provided to improve quality of the cast articles by improving wear resistance of the articles and preventing damage of the articles and improve productivity by reducing the fabrication process. CONSTITUTION: In a manufacturing method of high chromium cast articles on which a connection member(10) is integrally formed, the manufacturing method comprises a step of fabricating a wooden mold and/or metallic mold corresponding to the cast articles; a step of processing a connection structure part of the connection member and a flow preventing structure of insert part; a step of protecting the connection structure part of the connection member; a step of preheating the connection member; a step of molding a shape corresponding to the cast articles in a molding frame using the wooden mold and/or metallic mold; a step of inserting the preheated connection member into a corresponding position of the molding frame, and uniting the molding frames; a step of molding a cast article by injecting a Fe-Cr-X based molten material into the united molding frames; a step of desanding the surface of the molded cast article(1); and a step of heat treating the desanding cast article.

Description

Manufacturing method of high chrome castings {Manufacturing Method Of High-Cr casting}

The present invention relates to a method for producing a high chrome cast article molded into an integral member.

In the fields of steelmaking and cement manufacturing, mining and quarrying, the process of processing and transporting powders such as metal, sand and ore is indispensable. When constructing equipment such as powder receiving hopper and conveying pipe for this process, the equipment is manufactured by using plate materials, metal materials such as section steel and pipes, and when using these materials as general steel materials, It is difficult to handle the wear of metal materials due to friction. As a result, countermeasures for constructing powder processing and transfer line facilities using high-strength special steels such as high chromium steels having excellent wear resistance have been prepared.

However, while such high chromium special steel has excellent wear resistance, mechanical strength is not easy due to its unique high strength.

Therefore, when constructing a facility such as a hopper for accommodating powder or a conveying line for conveying powder by combining materials made of high chrome steel with each other, bolts, nuts, and other joint members such as joints are made of high chrome steel and / or It is a situation that a facility is constructed by combining each material by special welding to the corresponding coupling parts of the formed plate, the section steel and the pipe.

However, in the conventional method of welding a coupling member such as a bolt to a high chromium steel, the welding work is difficult or impossible to weld itself, compared to general steel, and even if special welding is possible, it frequently damages cracks and deformations. There is a problem that causes product defects. In addition, there is a problem that the productivity is lowered by the addition of the welding process, leading to an increase in manufacturing costs.

Accordingly, if a high chromium steel having excellent wear resistance can be manufactured in a casting method and can be integrally formed with a coupling member such as a bolt, it is possible to reduce damage of the equipment due to abrasion in a field that requires equipment such as powder processing and a transfer line. It would be desirable to avoid damage to the product and improve productivity since no additional work steps, such as welding, are required during the fabrication of the facility.

Accordingly, it is an object of the present invention to provide a method for producing a high chrome cast article with a coupling member that is excellent in wear resistance, prevents damage to a product, and improves quality, thereby reducing productivity.

1 is a manufacturing process of the coupling member integrated casting according to the present invention,

2 is a view for explaining a coupling member protection process in the manufacturing process of FIG.

3 is a cross-sectional view of the cast article produced by the manufacturing process of FIG.

Figure 4 is a front view of the facility manufactured using the coupling member integrated casting in accordance with the present invention.

* Explanation of symbols for the main parts of the drawings

1: Casting 3: Plate

5: section steel 7: piping

10: coupling member 11: bolt

13: nuts

The object is, according to the present invention, in the manufacturing method of the high chrome castings in which the coupling member is integrally formed, manufacturing a die and / or mold corresponding to the casting, and the coupling structure portion of the coupling member And processing the flow preventing structure of the insert portion, protecting the coupling structure portion of the coupling member, preheating the coupling member, and using the wood and / or mold to mold the casting. Molding a shape corresponding to the mold, inserting the preheated coupling member into a corresponding position of the mold, and molding the mold, and melting the Fe-Cr-X-based melt into the molded mold. Forming a casting by injecting, desalarizing the surface of the molded casting, and heat-treating the desalated casting. Of it is achieved by the method.

Wherein the coupling structure of the coupling member is a female screw and / or a male screw; The step of protecting the coupling structure portion is a step of sealing the female screw-shaped portion before the insert when the coupling structure is a female screw shape, and when the coupling structure is a male screw shape, the male screw-shaped portion is surrounded by a protective member before the descaling treatment. Is preferably a step.

In addition, the preheating temperature of the preheating step is effectively 150 ℃ to 300 ℃.

At this time, the lysate is Cr: 15 to 30% by weight, C: 2.0 to 3.0% by weight, Si: 0.5 to 1.5% by weight, Mn: 0.5 to 1.5% by weight, P: 0.04% by weight or less, S: 0.030% by weight Hereinafter, Mo: 0.3 to 3.0% by weight, Ni: 0.2 to 3.0% by weight, V: 0.2 to 3.0% by weight, W: 0.2 to 3.0% by weight, B: 0.01 to 0.5% by weight and more preferably consist of the remaining Fe Do.

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

1 is a manufacturing process of the coupling member integrated high chrome castings according to the present invention. As shown in this figure, the method of manufacturing a high chrome cast article integrally coupled member according to the present invention, the step (S01) of producing a die and / or mold of the casting (1 of Figure 3), and the coupling member ( Step 10 of FIG. 3 (S02), protecting the coupling structure portion of the coupling member 10 (S03), preheating the coupling member 10 (S04), and molding ( S05), the step of molding (S06), the step of molding the casting (1) by injecting the melt (S07), the step of desalatizing the surface of the molded casting (1), It includes the step (S09) of heat-treating the desalted casting (1).

Step (S01) of manufacturing the die and / or mold of the casting (1) is a plate (3 in FIG. 3) and the shape steel (FIG. 3) for forming the shape of the hopper (100 in FIG. 4) for receiving and processing the powder 5) Shapes of materials such as the plate 3 and the shaped steel 5 and the piping 7 in order to produce the material or the pipe (7 in FIG. 3) forming the conveying line of the powder as the casting product 1 The step of producing a die and / or mold corresponding to. In this step, in consideration of inserting the coupling member 10 such as the bolt 11, the nut 13 and the like to form a structure capable of supporting the coupling member 10 in the die and / or mold.

Step (S02) of processing the coupling member 10, as shown in Figure 2, the coupling of the male screw structure and protrusion structure or female screw structure and hole structure, such as bolt 11, nut 13, etc. Forming a structure, and forming the flow preventing structure 17 in the insert portion 15 of the coupling member (10). The flow preventing structure 17 is to ensure that the coupling member 10 is firmly joined without flow when the coupling member 10 is integrally molded to the casting product 1, and grooves, protrusions, and ribs are inserted into the insert portion 15 of the coupling member 10. It may be formed in the shape of.

Protecting the coupling structure portion of the coupling member (10 in FIG. 2) (S03) is a coupling member 10 in the step of molding the casting (1) by injecting the melt or the desalination process of the casting (1) It is a step for preventing damage to the coupling structure parts such as the female screw and the hole structure or the male screw and the projecting structure.

At this time, when the coupling member 10 is a coupling member 10 such as a nut 13 having a female thread or a hole-shaped coupling structure, before the coupling member 10 is inserted into the mold (not shown) in the molding step. As shown in Fig. 2A, the female screw portion is sealed with shell sand or silica sand. This is to prevent the melt from entering the female screw portion when injected into the mold (not shown).

On the other hand, when the coupling member 10 is a coupling member 10 such as a bolt 11 or the like having a male screw or a protruding coupling structure, the casting product 1 in which the coupling member 10 is integrally formed is desalted. Before the male screw portion as shown in Figure 2b, it is surrounded by a protective member 21, such as a pipe material and maintained in a protected state with a fixing nut (23). This is to prevent the coupling structure of the male screw portion from being damaged when the casting product 1 is de-scattered in a shot blasting machine.

Here, the timing of protecting the coupling structure portion such as the female screw structure or the male screw structure of the coupling member 10 may be determined before inserting the coupling member 10 into a mold (not shown) and / or before removing the casting product 1. can do.

Preheating the coupling member 10 (S04) is a step of preheating to a temperature of 150 ℃ to 300 ℃ before inserting the coupling member 10 in the mold (not shown). This prevents the melt from splashing due to the temperature difference between the melt and the coupling member 10 when the melt is injected while the coupling member 10 is inserted into the mold (not shown). This is to prevent the poor bonding between 10) and the melt. Here, the coupling member 10 is preferably subjected to a process of removing impurities before preheating.

Molding step (S05) is to fill the molding sand in a state in which the mold and / or mold corresponding to the casting (1) to be molded in the molding die (not shown) to fill the casting (1) in the mold (not shown) Forming a corresponding shape. In this case, the shape of the coupling member 10 may be previously formed on the die and / or the mold, and the coupling member 10 may be disposed in a mold (not shown) like a mold.

Forming step (S06) in the space of the casting (1) shape formed in the molding frame (not shown), and mounting the coupling member 10 in the corresponding position (insert position) and then molding the upper and lower molds of the molding frame (not shown) It's a step. At this time, the coupling member 10 has an insert portion 15 having a cast product 1 in which a flow preventing structure 17 (groove, protrusion, rib) of the processed insert portion 15 is formed in a mold (not shown). Located in

Step (S07) of molding the casting (1) is to inject the melt of a high chromium system (Fe-Cr-X (other mixtures)) into a molded mold (not shown) to form the casting (1) Step. Melt injected into the mold (not shown) is Cr: 15 to 30% by weight, C: 2.0 to 3.0% by weight, Si: 0.5 to 1.5% by weight, Mn: 0.5 to 1.5% by weight, P: 0.04% by weight or less , S: 0.030 wt% or less, Mo: 0.3 to 3.0 wt%, Ni: 0.2 to 3.0 wt%, V: 0.2 to 3.0 wt%, W: 0.2 to 3.0 wt%, B: 0.01 to 0.5 wt%, and the rest It is made of Fe. At this time, when the melt is injected into the mold (not shown), it is in contact with the pre-heated coupling member 10 is injected without splashing. In addition, the coupling structure such as the female screw and / or male screw of the inserted coupling member 10 does not come into contact with the injected melt because it is protected in advance in the protecting step of the coupling member 10.

Descaling the surface of the molded product (1) (S08) is a step of removing the molding sand on the surface of the molded product (1) in the mold (not shown). This step is carried out in such a way that the shot product is short-processed in the shot blasting machine 1 in which the coupling member 10 is integrally formed. At this time, the coupling structure such as the male screw of the coupling member 10 is protected in the protection step to prevent damage at the time of short.

The step (S09) of heat-treating the casting (1) is made by quenching the finished casting (1) at 960 ° C to 1050 ° C after tempering at 150 ° C to 250 ° C. The cast product 1 in which the heat treatment process is completed is completed with a high hardness cast product 1 having an HRC hardness of 60 or more.

On the other hand, Figure 3 is a cross-sectional view of the cast article produced by the manufacturing process of Figure 1, Figure 4 is a front view of a facility manufactured using the coupling member integrated casting (1) according to the present invention. As shown in these figures, the coupling member-integrated high chrome casting 1 produced by the manufacturing process of FIG. 1 is composed of the plate 3 of FIG. 3A, the shape steel 5 material of FIG. 3B, and the piping of FIG. 7) It can be produced in various forms such as materials.

As shown in FIG. 4 using the high chrome castings 1, such as the board | plate material 3 and the shaped steel 5, when manufacturing the powder accommodating hopper 100, the bolt 11, the nut 13, etc. By mutually coupling the coupling member 10 formed integrally with the chrome casting (1), it is possible to easily build a facility of the desired shape, such as the hopper (100). In particular, by not welding the coupling member 10, such as the bolt (11) nut 13, the workmanship is significantly reduced as well as productivity is significantly improved.

At this time, the equipment such as the hopper 100 may be manufactured only by the high chrome casting (1) in the form of a plate (3) and the shape steel (5), and the appearance of the equipment such as the hopper (100) such as general steel plate and the shape steel The sheet | seat 3 shape | molded with the high chrome casting 1 can also be installed in the equipment inner wall surface (virtual line "A"), such as the hopper 100, in the state previously prepared with the material of the material. In addition, it is also possible to reinforce the old equipment used in the plate material (3) and the shape steel (5) made of high chrome casting (1).

On the other hand, as shown in Figure 4, the high chrome castings (1) in the form of a pipe (7) for building equipment, such as powder transfer line for forming also integrally molded to the casting (1) without a separate bonding operation By combining the coupling member 10 to each other it is possible to build a powder transfer line of the desired shape.

Thus, by forming a plate, a section steel and a tubular material with high chromium castings having excellent abrasion resistance, and providing a method of integrally forming a coupling member such as bolts and nuts, powders such as metal, sand, ore are processed. In the field requiring the transfer equipment can reduce the damage of the equipment due to wear, and can be easily manufactured without additional work processes such as welding work during the production of the equipment is improved productivity.

Although the present invention has been described in the above and the embodiment by using the coupling member as a bolt and / or nut, according to the technical idea of the present disclosure, the coupling member may be changed into various types of components. In addition, although the object of the casting is described as a plate, a section steel, piping, etc., the object of the casting can also be variously applied.

As described above, according to the present invention, there is provided a method of manufacturing a high chrome cast article with a coupling member that is excellent in wear resistance, prevents damage to a product, and improves quality, thereby reducing productivity.

Claims (4)

In the manufacturing method of the high chrome castings are molded integrally, Manufacturing a die and / or mold corresponding to the casting product; Machining the flow preventing structure of the coupling structure portion and the insert portion of the coupling member; Protecting the coupling structure portion of the coupling member; Preheating the coupling member; Molding a shape corresponding to the casting on the mold using the die and / or mold; Inserting the preheated coupling member into a corresponding position of the mold and molding the mold; Injecting a melt of Fe-Cr-X-based in the molded mold to form a casting product, Desalting the surface of the molded article; Method for producing a high chromium casting, characterized in that it comprises the step of heat-treating the desalated casting. The method of claim 1, The coupling structure of the coupling member is female and / or male thread shape; The step of protecting the coupling structure portion is a step of sealing the female screw-shaped portion before the insert when the coupling structure is a female screw shape, and when the coupling structure is a male screw shape, the male screw-shaped portion is surrounded by a protective member before the dethreading treatment. Method for producing a high chrome castings, characterized in that the step. The method of claim 1, The preheating temperature of the preheating step is a method for producing a high chromium casting, characterized in that 150 ℃ to 300 ℃. The method of claim 1, The melt is 15 to 30% by weight, C: 2.0 to 3.0% by weight, Si: 0.5 to 1.5% by weight, Mn: 0.5 to 1.5% by weight, P: 0.04% by weight or less, S: 0.030% by weight, Mo: 0.3 to 3.0 wt%, Ni: 0.2 to 3.0 wt%, V: 0.2 to 3.0 wt%, W: 0.2 to 3.0 wt%, B: 0.01 to 0.5 wt% Method for producing chrome castings.