JPS6281249A - Production of wear resistant material - Google Patents

Abstract

PURPOSE:To obtain a wear resistant material consisting of fine Si crystal particles by horizontally and continuously casting a molten aluminum alloy contg. Si as an essential alloy component in a highly cooled state and cutting the cast alloy to a required length, then machining the cut alloy. CONSTITUTION:The molten Al alloy 4 is conducted through the lower part of a tundish 2 directly to a water-cooled casting mold 6 disposed in a horizontal direction. The mold 6 is cooled by the cooling water 8 flowing in a cooling water chamber to cool and solidify the molten Al alloy 4. The cooling water 8 is then ejected from an ejection port 14 provided to the casting material outlet part of the mold 6 to further cool the plate-shaped casting material 10 which is then taken out in a horizontal direction by pinch rolls 12. THe stock 18 of a prescribed size cut by a cutter 16 is then machined and the wear resistant material consisting of the considerably fined eutectic Si grains is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for producing a wear-resistant material, which has excellent properties and can be suitably used in wear-resistant members such as vane materials for compressors. This invention relates to a method for manufacturing materials inexpensively and continuously.

(Prior art and its problems) Traditionally, sliding members that require wear resistance and high strength properties, such as compressor vane materials, have been made using A.
390 alloy (Aj! -18%S i -4,5%Cu
-0.55% Mg) and other Al-3i based casting alloys have been widely used. However, such casting alloys have
There are problems in that casting defects such as cavities or inclusions are likely to occur and the yield is poor. Furthermore, in order to improve wear resistance, it is necessary to add a treatment agent (such as P) to this type of alloy to make the primary Si particles finer. .

On the other hand, there is a method in which an extrusion billet is made by continuous casting without using the above-mentioned casting, and vane material is manufactured by extrusion, but with this method, when the Si content becomes high, primary Si crystals are produced. It becomes difficult to make extruded billets that are uniformly and finely dispersed, which causes problems such as uneven quality of the vane material obtained by extrusion, significant wear of extrusion dies, and cost-effective heating of billets. This method is disadvantageous because it requires an extrusion process. Furthermore, this method also requires treatment to refine the primary St grains, as in the case of cast alloys.

(Structure of the Invention) The present invention has been made against the background of the above, and its object is to provide a compressor vane material etc. of stable quality and excellent wear resistance. An object of the present invention is to provide a wear-resistant material that can be suitably used as a sliding material.

In order to achieve this object, the present invention uses a molten aluminum alloy containing St as a main alloy component.
A process of horizontally continuous casting under high cooling conditions using water cooling to obtain a predetermined plate-shaped cast material, and cutting the continuously produced cast material into the required length using a cutting device connected to the casting device. Furthermore, the cut cast material is then subjected to predetermined processing such as cutting, thereby producing a wear-resistant material with stable quality and fine Si crystallized particles in a simple manner. The standardized manufacturing process has made it possible to manufacture it extremely efficiently.

(Specific description of the structure) By the way, when implementing the present invention, it will be carried out as shown in FIG. 1, for example. That is, in FIG. 1(a), 2 is a tundish, and within this tundish 2, a molten A/alloy 4 containing a predetermined Si as a main alloy component is accommodated and held. In addition, the molten metal 2 alloy 4 generally has a Si content of 2 to 30% in the eutectic, hypoeutectic, or even hypereutectic region.
Al-3t system, Al-3i-Cu system, A1A1-3i
-Cu- type AA alloy melt will be used.

The A1 alloy molten metal 4 in this tundish 2 is
Through the lower part of the tundish 2, it is guided into a cylindrical direct water-cooled mold 6 arranged horizontally. This mold 6 is cooled by cooling water 8 flowing through a cooling water chamber provided inside the mold 6, and thereby cools and solidifies the molten AI1 alloy 4 led from the tundish 2. The plate-shaped cast material IO is taken out in the horizontal direction by pinch rolls 12, table rollers, etc. Note that the direct water cooling mold 6 is
It has a slit-shaped casting hole corresponding to the cross-sectional shape of the target plate-shaped cast material 10. In addition, in order to completely solidify the plate-shaped cast material 10 that is continuously taken out from the direct water-cooled mold 6, as shown in FIG. A jet nozzle 14 communicating with the cooling chamber is provided, and the plate-shaped cast material 10 is further cooled by the cooling water 8 spouted through the nozzle 14.

Therefore, by continuously casting a predetermined plate-shaped cast material 10 such as a vane material for a compressor using the horizontal continuous casting method, both sides of the plate-shaped cast material 10 can be directly cooled by water cooling. As a result, a high cooling rate can be obtained, and as a result, eutectic Si, primary St, etc. can be uniformly refined. For this reason, there is almost no need for eutectic improvement treatment or treatment for thinning the primary crystal, and such Si
Even when adding additives for micronization, the amount required is smaller than in the past, and the yield is significantly improved.

By the way, A/! Hypoeutectic and eutectic alloys of -4 to 12% Si alloys have poor machinability and wear resistance when the eutectic Si crystallized phase particles are coarse, but according to the method of the present invention, the eutectic S
The i-grains are 10 μm or less, and the mechanical properties are effectively improved. Moreover, in this case, Na,
No improvement treatment with a finer agent such as Sr is required.

In addition, in hypereutectic alloys with /Mt-13 to 30%St, as the primary Si increases, the wear and abrasion resistance of the cutting tool deteriorates, so the primary Si grains of 50 to 100 μm are usually
However, according to the method of the present invention, fine primary Si grains can be obtained without adding P as a refiner due to the quenching effect.

In addition, the plate-shaped cast material 10 cast according to the present invention generally has a plate thickness/plate width ratio of 1/2 or less, and usually
The plates are continuously cast in sizes ranging from approximately 5 mm to 30 mm in thickness and approximately 30 mm to 250 mm in width.

In particular, in the present invention, a thinner plate is preferable in order to obtain a high cooling state, and in particular, a cast material 10 with a plate thickness of 15 mm or less is suitably cast. Depending on the cooling rate, it is possible to more effectively refine and homogenize the crystallized substances inside the cast material.

The plate-shaped cast material 10 obtained by continuous horizontal casting in this way is cut by a cutting device (such as a flying saw) connected to the casting device, as shown in FIG. 1(a).
The cast piece 18 obtained by cutting the cast piece 18 to a required length is then subjected to a predetermined process such as cutting to finish it as a desired wear-resistant material.

In order to facilitate or simplify the processing into this wear-resistant material, the shape of the plate-shaped cast material 10 is changed as shown in FIG. 2(a).
It is desirable to have a shape close to the final product shape as shown in (d), and thereby the amount of machining in a predetermined machining step, such as the amount of finishing cutting, can be reduced.

(Effect of the invention) As is clear from the above explanation, if the method of the present invention is followed,
Components that require wear resistance and high strength can be obtained directly and continuously from the hot melt, which is close to the final product, and because of the continuous casting method, the quality of the cast material is stable, making it possible to obtain parts that require high wear resistance and high strength. The defects observed in other cases are almost never observed.

Moreover, since plate-shaped cast materials, especially thin plates, are directly cast by water cooling, a high cooling rate can be obtained, and eutectic St and primary St
becomes fine, and for this reason, eutectic improvement treatment or primary S
Treatment for grain refinement is hardly required, and even if such treatment is necessary, the amount of treatment agents such as grain refiners may be small compared to conventional methods, and Yield is also improved.

Furthermore, the wear resistance of the member manufactured by the method of the present invention,
Properties such as strength are superior to conventional materials,
Moreover, the manufacturing process can be simplified and costs can be reduced, which is the great industrial significance of the present invention.

(Examples) Below, some examples of the present invention will be shown to clarify the present invention more specifically, but the present invention shall not be construed to be equally limited by the description of such examples. It should be understood that this is not the case.

In addition to the specific examples described above and the embodiments illustrated below, the present invention includes
It goes without saying that the present invention may be implemented in forms with various modifications, improvements, modifications, etc. based on the knowledge of those skilled in the art, and that the present invention includes such embodiments within its scope. be.

Example 1 Using a molten AN alloy having a composition of 1-13%St, a plate with a thickness of 8n was cast using the casting apparatus shown in FIG. 1(a).
゛Thin plate material 10 with a plate width of 60 mm is continuously cast according to a normal horizontal continuous casting method, and the continuously obtained cast material 10 is cut into a desired length by a cutting device (flying saw) 16. did.

Since the thus obtained cast material was rapidly cooled by direct water cooling from both the upper and lower surfaces during casting, its dendrite arm basing was 4 to 6 μm.

The cooling rate was estimated from this value to be 100-b. In addition, the Si particle size in the obtained cast material was 20 to 3
The St grain size was 0 μm, and although the conventional primary Si refinement treatment was not carried out, the St grain size was comparable to that of the refinement treatment. Moreover, this cast material also has Si in the longitudinal direction.
It was observed that the grains were uniformly refined.

Then, the thus obtained material (cast piece 18) cut into a predetermined size by the cutting device 16 could be used as the intended compressor vane material by subjecting it to minimal cutting.

On the other hand, using A390 alloy molten metal with approximately the same Si content,
When castings for vane materials were cast according to the conventional method, the occurrence of cavities and inclusion of oxides were observed, as well as segregation of primary Si due to precipitation of primary Si, which caused problems in terms of performance and quality. It was also poor.

In addition, when an extrusion billet (6"φ) was cast using the normal continuous casting method using molten A390 alloy, the primary Si crystals became coarser at the center of the ingot, that is, as the cooling rate became lower, and from the casting surface. The primary Si grain size changed from about 10 μm to 40 μm up to the center of the ingot.

Example 2 A7 with a composition of Al-8%5i-2%Cu-0.8%Mg! Using the molten alloy, horizontal continuous casting was performed in the same manner as in Example 1 to produce a continuous thin plate material with a thickness of 10 mm and a width of 100 mm. Next, this thin plate material was sequentially cut into predetermined lengths using a cutting device (flying saw) 16, and the obtained thin plate pieces (18) were cut to obtain the intended compressor vane material.

The eutectic Si grains in this vane material were significantly refined by high cooling using the horizontal casting method, and the structure was uniform.

[Brief explanation of drawings]

Figure 1 (a)! 1(b) is an enlarged explanatory view showing an outlet portion of the direct water bath mold; FIG. a) to (d) are explanatory diagrams each showing a cross-sectional shape of a plate-shaped cast material manufactured according to the present invention. 2: Tanditsh 4: Molten A6 alloy 6: Direct water cooling mold 8: Cooling water 10: Plate-shaped casting material
12: Pinch roll 14: Spout 1
6: Cutting device 18: Cast piece Applicant: Sumitomo Light Metal Industries, Ltd. (b)

Claims (3)

[Claims] (1) A molten aluminum alloy whose main alloy component is Si is horizontally continuously cast under high cooling conditions by water cooling to obtain a predetermined plate-shaped cast material, and the continuously produced cast material is cast. A method for manufacturing a wear-resistant material, which includes the step of cutting the cast material into a required length using a cutting device connected to the device, and then subjecting the cut cast material to a predetermined process such as cutting. (2) The method for producing a wear-resistant material according to claim 1, wherein the molten aluminum alloy contains Si as an alloy component in a proportion of 2 to 30% by weight. (3) The method for producing a wear-resistant material according to claim 1 or 2, wherein the plate-shaped cast material has a width of 30 to 250 mm and a thickness not exceeding 15 mm.