KR20070065570A - Method of producing wear resisting machine part - Google Patents

Abstract

A method of producing a wear resistant machine part is provided to produce a machine part with excellent impact resistance and wear resistance by bonding a wear resistant steel having wear resistance against a counter medium to an alloy steel casting matrix having sufficient impact toughness simultaneously during casting. In a method of producing a wear resistant machine part by bonding a wear resistant steel to an alloy steel casting matrix, the method comprises: a step(S10) of machining the wear resistant steel to a predetermined size; a step(S20) of coating an oxidation resistant material with inert and reductive properties on a surface of the wear resistant steel; a step(S30) of laying up the wear resistant steel on a mold to fix the wear resistant steel to the mold; a step(S40) of pouring an alloy steel casting melt into the wear resistant steel laid-up mold; a step(S50) of cooling the material in the mold in the atmosphere; and a step(S60) of removing the mold from a wear resistant part obtained by bonding an alloy steel casting matrix to the wear resistant steel.

Description

METHODS OF PRODUCING WEAR RESISTING MACHINE PART}

1 is a block diagram showing a method of manufacturing a wear-resistant mechanical part according to the present invention.

The present invention relates to a mechanical part having wear resistance, and in particular, a method for manufacturing wear resistant mechanical parts for use in frictional contact parts of equipment requiring wear resistance by joining an alloy cast steel material and a wear resistant high carbon alloy steel material with an alloy cast steel base material at the time of casting. It is about.

In general, the excavator bucket of the work equipment of construction machinery is abrasion caused by the relative medium such as soil, rock, earth and sand during the excavation work, to improve the wear resistance of such work equipment to extend the working time, Improved durability results in lower maintenance costs of the device.

Therefore, parts such as buckets of excavators need to improve the wear resistance of the material constituting the buckets, in particular because they require abrasion resistance.

Tooth and side cutters used in conventional tooth working apparatuses such as the bucket are required to have abrasion resistance against abrasion with a relative medium, and at the same time, the bucket has to satisfy resistance to strong impact when working.

In addition, the tooth or side cutter used in the conventional working machine for construction machinery is cast alloy alloy steel in a constant shape (casting) to produce the alloy cast steel for satisfying the two characteristics because it is required to withstand strong impact and wear resistance Difficult to determine the ingredients

That is, it is effective to increase the amount of carbon in the components of the alloy cast steel in order to improve the wear resistance, if the carbon content of 0.45wt% or more is added, the hardness of the alloy cast steel base material is increased and wear resistance is improved, but there is a problem that it is fragile and easily broken Because of the difficulty in designing casting schemes, casting defects are more likely to occur inside components.

In addition, alloy cast steel added with a low carbon (0.35wt% or less) carbon amount is high in toughness to impact but small in hardness, it is difficult to secure sufficient wear resistance.

Therefore, in the case of the low carbon alloy cast steel, expensive alloy elements such as chromium (Cr), molybdenum (Mo), nickel (Ni), boron (B), manganese (Mn), etc. are used to improve hardness and improve hardening performance. Since it is produced by adding a large amount is relatively expensive, and also has a small amount of carbon has a limit in improving the hardness of the alloy cast steel.

Accordingly, the present invention has been made to solve the problems of the conventional wear-resistant mechanical parts, the wear characteristics of the relative medium to the tough alloy alloy steel base material to have sufficient impact toughness in order to manufacture the mechanical parts excellent impact and wear resistance It is an object of the present invention to provide a method for producing a wear-resistant mechanical part that is simultaneously joined at the time of casting the wear-resistant steel having.

The present invention for achieving the above object, in the manufacturing method of the wear-resistant mechanical parts for joining the alloy cast steel base material and the wear-resistant steel, the step of machining the wear-resistant steel material to a predetermined size, and the wear-resistant steel material Applying an oxidizing material having inertness and reducibility to the surface of the resin, laminating and fixing the wear-resistant steel to a mold, and injecting molten alloy steel melt in the mold to which the wear-resistant steel is laminated; And cooling the material in the mold in the air, and dismantling the mold from the wear-resistant part to which the wear-resistant steel material and the alloy cast steel base material are joined.

In addition, the wear-resistant steel material is coated with the oxidation resistant material is further comprises a step of removing water by heating to 200 ℃ or less.

In addition, the wear-resistant steel is composed of a high carbon alloy oral steel with a carbon content of 0.6wt% or more added, the oxidation-resistant material is boron and brazing paste to prevent the connection of the wear-resistant steel and alloy cast steel base material is oxidized at high temperature It consists of.

It further comprises a step of heat-treating the wear-resistant parts made of the wear-resistant steel and alloy cast steel by carburizing or quenching.

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

The method for manufacturing the wear-resistant mechanical part according to the present invention by joining the alloy cast steel base material and the wear-resistant steel material, as shown in Figure 1, machining the wear-resistant steel to a certain size (S10), the wear-resistant steel of Applying an oxidation-resistant material having an inert and reducing property on the surface (S20), by laminating and fixing the wear-resistant steel to the mold (S30), injecting the molten alloy cast molten metal in the mold laminated (S40) ), The material inside the mold is cooled in the air (S50), and the mold is dismantled (S60) from the wear-resistant part to which the wear-resistant steel material and the alloy cast steel base material are bonded to produce a wear-resistant mechanical part.

In addition, a process (S25) of removing moisture by heating the wear-resistant steel to which the oxidizing material is applied may be performed at 200 ° C. or less. That is to remove the moisture of the oxidizing material to suppress the generation of bubbles during the injection of the molten metal.

On the other hand, the wear-resistant steel is composed of high-carbon alloy steel, such as tool steel, bearing steel, mold steel, etc. is added to the carbon content of 0.6wt% or more, by machining the size of the wear-resistant steel to approximately 120 X 70 X t10 To make.

The high carbon alloy steel ball suitable as the wear-resistant steel is shown in Table 1 as follows.

TABLE 1

Material name Standard name Chemical composition C Si Mn P S Ni Cr Mo W V Alloy Tool Steels STD11 1.40-1.60 0.40 or less 0.60 or less 0.03 or less 0.03 or less 0.50 or less 11.0 ~ 13.0 0.8-1.20 - 0.20-0.50 High Speed Tool Steels SKH51 0.80-0.90 0.40 or less 0.40 or less 0.03 or less 0.03 or less - 3.80-4.50 4.50-5.50 5.50-6.70 1.60-2.20 High carbon chrome bearing steel STB4 0.95-1.10 0.15-0.35 0.50 or less 0.025 or less 0.025 or less - 1.30-1.60 0.1-0.25 - -

The sheet of high carbon alloy steel blank is cut and machined to a certain size. The alloy steel steel is an alloying element such as chromium, molybdenum, tungsten, and vanadium as an alloying element having a carbon content of 0.6wt% or more and forming carbide. At least one is added, it is preferable to select a steel having excellent hardening performance during heat treatment, high strength and excellent wear resistance.

On the other hand, in order to prevent rapid oxidation in contact with the high temperature alloy cast steel in the state of machining the wear-resistant steel is applied to the surface of the wear-resistant steel bar, the oxidation resistant material is composed of boron and brazing paste .

Table 2 shows an example of using the brazing paste.

TABLE 2

designation Chemical composition Cu Zn Si Ag P Sn Example 1 60 39.5 0.5 - - - Example 2 30 26 - 44 - - Example 3 93.8 - - - 6.2 - Example 4 27 25 - 45 - 3

Here, the boron and the brazing paste may be applied to the surface of the wear-resistant steel at the same time, the moisture of the boron and the brazing paste is removed to suppress the generation of bubbles during molten metal injection. To this end, the boron and the brazing paste, which are oxidation resistant materials, are applied to the wear resistant steel and then heated to 200 ° C. or less.

In particular, when high temperature alloy cast steel is in contact with the wear resistant steel, oxidation occurs on the surface of the wear resistant steel, thereby preventing boring of the alloy cast steel and the wear resistant steel by applying boron oxide and a brazing paste to prevent unbonding between the alloy steel and the wear resistant steel. Allow a layer to form.

The step (S30) of applying the oxidation resistant material and laminating the heated wear-resistant steel to a mold so as not to move in a mold is a process of locally fixing one or more of the wear-resistant steel to a portion where abrasion occurs. By forming grooves in the mold to prevent the wear-resistant steel material from shaking when injecting molten alloy steel.

Then, when the step (S30) of fixing the wear-resistant steel to the mold is completed, injecting molten alloy by melting the alloy cast bar (460), melting the alloy cast steel in the melting furnace in the air injection temperature is 1100 ℃ or more Inject at high temperature.

The process of injecting the molten alloy of the alloy cast steel (S40) is to use the steel of the alloy cast steel for the tooth or side cutter used in the existing work machine construction equipment, the alloy component is sufficiently dissolved in the melting furnace is installed in the mold Wear-resistant steel flows into the fixed mold through the spout.

Particularly, in order to suppress the occurrence of casting defects due to the reaction gas caused by the reaction between the wear-resistant steel and the alloy cast steel, it is preferable to form a gas hole capable of releasing gas at the junction portion.

On the other hand, when the step of injecting the molten alloy of the alloy cast steel (S40) is completed, the cooling is performed with a sufficient time in the atmosphere so that the reaction occurs in the wear-resistant steel and the alloy cast steel (S50), the mold in the cooled mold Remove the wear-resistant parts to which the wear-resistant steel and the alloy cast steel is bonded. That is, the process of removing the molding sand used as a mold (S60).

As described above, the wear-resistant parts from which the foundry sand has been removed increase their hardness through heat treatment (S70), and heat treatment conditions are important for increasing the hardness and improving the wear resistance of both the wear resistant steel and the alloy cast steel base material. Since the austerizing temperature of the wear-resistant steel and the austerizing temperature of the alloy cast steel are different, the internal hardness of the wear-resistant parts is simultaneously heat-treated by maintaining sufficient time to sufficiently heat the heating temperature from the temperature of 900 ° C. or higher to the deep part during carburizing or quenching heat treatment. Be sure to

As described above, according to the manufacturing method of the wear-resistant mechanical part according to the present invention, the wear resistance of the device can be improved by using a machine part having excellent wear resistance in a tooth or side cutter in direct contact with the mating medium in an excavator for construction machinery. By manufacturing a mechanical part having sufficient toughness and wear resistance, it is possible to prevent the mechanical part from being easily damaged during work.

Claims (5)

In the manufacturing method of wear-resistant mechanical parts for joining alloy cast steel base material and wear-resistant steel material, Machining the wear-resistant steel to a predetermined size (S10); Applying an oxidizing material having inertness and reducing properties to the surface of the wear resistant steel material (S20); Stacking and fixing the wear-resistant steel to a mold (S30); Injecting molten alloy steel melt in a mold in which the wear-resistant steel is laminated (S40); Cooling the material inside the mold in the air (S50); And dismantling the mold from the wear-resistant part to which the wear-resistant steel material and the alloy cast steel base material are joined (S60). The method of claim 1, further comprising the step (S25) of removing the moisture by heating the wear-resistant steel coated with the oxidation resistant material to 200 ° C or less. The method of claim 1, wherein the wear-resistant steel material is made of high-carbon alloy steel ball with an amount of carbon added 0.6wt% or more. The method of claim 1, wherein the oxidation resistant material is made of boron and a brazing paste, which prevent the oxidation of the joint of the wear resistant steel material and the alloy cast steel base material at high temperature. The method of claim 1, further comprising: heat-treating the wear-resistant part made of the wear-resistant steel and the alloy cast steel by carburizing or quenching (S70).

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