JPH09209069A - Wear resistant al alloy for elongation, scroll made of this wear resistant al alloy for elongation, and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an Al alloy having high strength, high wear resistance, fatigue strength at high temp., excellent toughness, and high deflectivity value and its production. SOLUTION: This wear resistant Al alloy for elongation has a composition which consists of, by weight, 8.0-13.0% Si, 0.1-0.5% Fe, 1.0-5.0% Cu, 0.4-1.5% Mg, 0.05-0.5% Cr, 0.05-0.5% Ni, 0.005-0.05% Sr or 0.05-0.3% Sb, and the balance Al with inevitable impurities and in which the amount of Mn as an inevitable impurity is limited to <=0.04wt.%. Moreover, this Al alloy has a metallic structure in which Si grains are finely dispersed, and further, the average circle- equivalent diameter of the Si grains is regulated to <=5.00μm and also the average degree of circularity is regulated to >=0.50.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an alloy and a method for manufacturing the same, a scroll made of wear-resistant Al alloy for wrought formed by forging, and a method for manufacturing the scroll. In particular, it relates to a wear-resistant Al alloy for expansion used for a compressor for an air conditioner, a piston for an engine which is an automobile part, a valve lifter, a rocker arm, etc., and a manufacturing method thereof. In addition to high wear resistance, Al with excellent fatigue strength at high temperatures, high toughness, and high bending strength
The present invention relates to an alloy and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, Al-Si type 4032 alloy (Al-12 wt% Si-1.0 wt% is used for automobile parts, electric products, machine parts, etc., which are required to have high strength and high abrasion resistance.
Mg-1.0wt% Ni alloy) extruded material, AC8A alloy (Al-12wt% Si-1.0wt% Mg-1.0w
A t% Cu-1.0wt% Ni alloy) casting, an ADC12 alloy (Al-11wt% Si-2.5wt% Cu alloy) die casting and the like have been used. In addition, in recent years, such parts have been manufactured by casting aluminum alloy extruded materials or cast bar materials (hot,
The ratio of cold-worked and used is increasing. On the other hand, with the demand for aluminum alloys, the required quality is changing and is becoming higher.

For example, scroll parts and wobble plate parts used in compressors of air conditioners are desired to have high strength and high wear resistance as well as toughness and fatigue strength at high temperatures. Similarly for automobile parts, 1 for piston, valve lifter and rocker arm of engine.
High strength and high wear resistance are required under a high temperature environment of 00 to 200 ° C., and a material having high fatigue strength and toughness at high temperature is desired. However, in the conventional aluminum alloy extruded material or cast bar material having the above composition, in addition to high strength and high wear resistance,
A material having both high fatigue strength and high toughness at high temperature has not been obtained. Further, for such purposes, Al-
6-15 wt% Si-Cu-Mg-Ni alloy with a small amount of F
Although an Al alloy extruded material added with e, Mn, Cr, Sr, and Ti has also been proposed (for example, JP-A-7-19716).
4) It cannot be said that it has all the various properties, and there is a problem that it is inferior in terms of high temperature fatigue strength and toughness.
Furthermore, the shape of the parts as these sliding members has become complicated, and in addition to the above characteristics, the bending strength represented by compressor scrolls has been newly demanded. So far, there has been no material excellent in all of the bending strength.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems. In addition to high strength and high wear resistance, fatigue strength at high temperatures, excellent toughness, and high bending resistance are also high. Provided are an Al alloy having a value and a method for producing the same, specifically, a hypoeutectic and eutectic composition having high strength and high wear resistance used for automobile parts, electric parts, machine parts, etc. Al
-Si-based alloys, in addition to high strength and high wear resistance, to improve fatigue strength and toughness at particularly high temperatures, and bending value, that is, an Al-Si-based alloy material having all of these characteristics,
An object of the present invention is to provide a scroll made of an Al alloy and a method for manufacturing them.

[0005]

According to the present invention, Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1 0.5 wt% Cr: 0.05 to 0.5 wt% Ni: 0.05 to 0.5 wt% Sr: 0.005 to 0.05 wt% or Sb: 0.0
5 to 0.3 wt%, the balance being Al and unavoidable impurities, and an Al alloy in which the Mn of the unavoidable impurities is regulated to 0.04 wt% or less, and having a metal structure in which Si particles are finely dispersed, It is characterized by having an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more, and having excellent high temperature fatigue strength, toughness and transverse rupture strength in a quenching age hardening heat treatment state. It is a wear-resistant Al alloy for elongation.

In the present invention, Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05-0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Zn: 0.25 wt% or less, the balance consisting of Al and inevitable impurities, and 0.04 wt% of Mn of the inevitable impurities
An Al alloy regulated below, having a metal structure in which Si particles are finely dispersed, and having an average equivalent circle diameter of the Si particles of 5.0.
0 μm or less and an average circularity of 0.50 or more,
Excellent high-temperature fatigue strength, toughness, and
Abrasion resistant Al for wrought, characterized by having bending strength
Alloy.

In the present invention, Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05-0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Ti: 0.1 wt% or less, and / or B: 0.05 wt
%, The balance is Al and unavoidable impurities, and Al whose Mn of the unavoidable impurities is regulated to 0.04 wt% or less
The alloy has a metal structure in which Si particles are finely dispersed, and the Si equivalent particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more. It is a wear-resistant Al alloy for wrought which is characterized by having excellent high temperature fatigue strength, toughness, and bending strength.

In the present invention, Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05-0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Zn: 0.25 wt% or less Ti: 0.1 wt% or less, and / or B: 0.05 wt
%, The balance is Al and unavoidable impurities, and Al whose Mn of the unavoidable impurities is regulated to 0.04 wt% or less
The alloy has a metal structure in which Si particles are finely dispersed, and the Si equivalent particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more. It is a wear-resistant Al alloy for wrought which is characterized by having excellent high temperature fatigue strength, toughness, and bending strength.

In addition, the present invention provides an aluminum alloy ingot of 480 to 5
Homogenized heat treatment is performed at 40 ° C. for 2 hours or more, and then hot extrusion or hot rolling is performed to have a metal structure in which Si particles are finely dispersed, and the average equivalent circle diameter of the Si particles is 5.00 μm.
The average degree of circularity is 0.50 or more, and is then forged, held at 490 ° C. to 520 ° C. for 30 minutes to 4 hours, water-quenched, and then artificially aged at 170 ° C. to 190 ° C.
The method for producing a wear-resistant Al alloy for wrought according to any one of the above, characterized by performing a quenching age hardening heat treatment for 4 to 16 hours.

According to the present invention, there is further provided a scroll made of wear-resistant Al alloy for wrought according to any one of the above, which is characterized by being formed by forging and then subjected to quenching age hardening heat treatment. is there. Further, according to the present invention, forging is performed at a forging die temperature of 120 to 170 ° C. and a material temperature of 22.
0-370 ° C, ram descending speed 200-800 mm / se
A scroll made of the above wear-resistant Al alloy for wrought, characterized in that it is formed by a single forging process using a lubricant for cold forging containing MoS ₂ under the condition of c. Is.

Furthermore, the invention provides an aluminum alloy ingot 480-800.
Homogenization heat treatment is performed at 540 ° C. for 2 hours or more, and then hot extrusion or hot rolling is performed to have a metal structure in which Si particles are finely dispersed, and the Si particles have an average equivalent circle diameter of 5.00 μm.
m or less and an average circularity of 0.50 or more, followed by a forging die temperature of 120 to 170 ° C. and a material temperature of 220 to 370.
At a ram and a ram descending speed of 200 to 800 mm / sec, a single forging process was performed using a cold forging lubricant containing MoS ₂ , and subsequently 490 ° C. to 520 ° C.
The above-mentioned excellent dimensional accuracy after forging is characterized by performing water quenching after holding at 30 ° C. for 4 hours and then artificial aging treatment at 170 ° C. to 190 ° C. for 4 to 16 hours. Is a method for manufacturing a scroll made of wear-resistant Al alloy for wrought.

[0012]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail.
First, the reason for limiting the alloy composition will be described. Si is
Crystallized as hard eutectic Si in the matrix of aluminum alloy, mainly improving wear resistance and lowering thermal expansion coefficient. The content is limited to 8.0 to 13.0 wt% because the effect is poor when it is less than 8.0 wt%, and coarse primary crystal Si crystallizes when it exceeds 13.0 wt%.
This is because the toughness and the fatigue strength at high temperature are significantly reduced. Si content is preferably 10.0 to 12.0 wt
%.

Cu imparts tensile strength and wear resistance to the aluminum alloy. Its content is 1.0-5.0 wt
%, The effect is insufficient if it is less than 1.0 wt%, and if it exceeds 5.0 wt%, the forgeability is remarkably reduced, and further the corrosion resistance is lowered and stress corrosion cracking easily occurs. Is. The Cu content is preferably 2.
It is 0 to 4.0 wt%.

Mg gives strength by forming a precipitate of Mg ₂ Si. The content is limited to 0.4 to 1.5 wt% because the effect is insufficient if it is less than 0.5 wt% and the elongation decreases if it exceeds 1.5 wt%, forging workability and high temperature fatigue. This is because the strength deteriorates. The Mg content is preferably 0.5 to 1.2 wt%.

Cr improves wear resistance. The content is limited to 0.05 to 0.5 wt% is 0.05 w
This is because if it is less than t%, the effect is insufficient, and if it exceeds 0.5 wt%, a coarse compound is formed and the fatigue strength at high temperature is lowered. The Cr content is preferably 0.05 to
It is 0.3 wt%.

Fe has the effect of increasing the hardness of the aluminum alloy, and the inclusion of Fe improves the wear resistance of the aluminum alloy. Its content is 0.1
The reason why the content is limited to 0.5 wt% is that if it is less than 0.1 wt%, its effect is insufficient, and if it exceeds 0.5 wt%, large crystallized substances are generated and the fatigue strength at high temperature is lowered. .

Ni improves heat resistance and high temperature fatigue strength. The reason why the content is limited to 0.05 to 0.5 wt% is that the effect is insufficient if it is less than 0.05 wt%,
This is because if it exceeds 0.5 wt%, not only the effect is saturated, but also a coarse compound such as Al ₃ Ni is formed to reduce the fatigue strength at high temperature. The Ni content is preferably 0.2 to 0.3 wt%.

Sr is added during casting and refines primary crystal Si and eutectic Si during solidification of the alloy to improve wear resistance, strength, toughness and forgeability, but the amount added is 0.005.
The reason why the content is limited to 0.05 wt% is that the effect is not sufficient if it is less than 0.005 wt%, and the effect is saturated if it exceeds 0.05 wt%, resulting in an unnecessarily high cost. The Sr content is preferably 0.01
˜0.03 wt%.

Further, Sb, like Sr, is added at the time of casting and refines primary crystal Si and eutectic Si during solidification of the alloy,
It improves wear resistance, strength, toughness, and forgeability,
The reason why the addition amount is limited to 0.05 to 0.3 wt% is
If it is less than 0.05 wt%, the effect is not sufficient, and if it exceeds 0.3 wt%, the effect is saturated, which unnecessarily increases the cost. The Sb content is preferably 0.1 to 0.2 wt%. Sr and Sb may be added at the same time, but since the effect is the same as when added alone, Sr: 0.005-0.05 wt%
Added alone, or Sb: 0.05 to 0.3
wt% is added and contained alone.

Zn has the function of increasing the hardness of the aluminum alloy, and the addition of Zn improves the wear resistance. The content is 0.25 wt%
The reason for limiting the content to the following is that if the content exceeds 0.25 wt%, the forgeability is reduced, the corrosion resistance is also reduced, and stress corrosion cracking is likely to occur. The Zn content is preferably 0.15 wt% or less.

Ti is for refining the crystal grains of the matrix of the aluminum alloy of the present invention. The content of 0.1 wt% or less means that the effect is saturated when the content exceeds 0.1 wt%, and This is because a coarse intermetallic compound is generated to reduce the high temperature fatigue strength. The Ti content is preferably 0.08 wt% or less. B is Ti
The grain size is made finer in the same manner as the above, and the content of 0.05 wt% or less means that the effect is saturated when it exceeds 0.05 wt% and the coarse intermetallic compound AlB ₂ is crystallized. This is because the high temperature fatigue strength is reduced. The B content is preferably 0.01 wt% or less. Then, Ti: 0.1 wt% or less alone is contained,
B: 0.05 wt% or less alone, or T
Both i: 0.1 wt% or less and B: 0.05 wt% or less are included.

The impurity Mn has a content of 0.04 w.
It is necessary to regulate it to t% or less. The reason is the primary crystal S
This is because i, the eutectic Si is made spherical and at the same time coarsening is prevented, and fatigue strength and toughness at high temperature are improved. When Mn exceeds 0.04 wt%, it induces crystallization coarsening of primary crystal Si and coarsening of eutectic Si, and at the same time Al-Fe-
It produces a Si-Mn-based coarse intermetallic compound, significantly reduces fatigue strength and toughness at high temperatures, and increases its variation. Preferably, it is desirable to regulate the Mn content to 0.02 wt% or less.

Next, the dispersed state of Si particles in the present invention will be described. It is a feature of the present invention that not only the particle size of Si particles but also the shape (circularity) is controlled. Here, the circularity of Si particles represents a degree of circularity, and is a parameter that represents an average degree of circularity of particles when a perfect circle is 1. These measurements can be obtained, for example, as follows by image analysis of a metal structure photograph.

With respect to the structure of the test material, a microstructure photograph taken with a metallurgical microscope at 400 times is subjected to image analysis by an image analyzer to measure the size and shape of Si particles.
For the size of the Si particles, the area equivalent to the Si particles is replaced by an area-equivalent circle by image analysis, and the average equivalent circle diameter that represents the circle and is the average Si particle diameter is determined as follows. For the shape of the Si particles, the average circularity, which is the degree of circularity when the perfect circle is set to 1, is obtained by image analysis as follows.

The circularity of the Si particles is shown in FIG. This illustrates the circularity by exemplifying the shape of the Si particles dispersed in the metal structure in the wrought wear-resistant Al alloy of the present invention. In the shape 1 of FIG. 1A, the Si particles are substantially circular and the circularity is 1.00. FIG.
In the shape 2 of (b), the circularity of the Si particles is 0.78,
In the shape 3 of FIG. 1C, the circularity of the Si particles is 0.50. In the shape 4 of FIG. 1D, the Si particles are needle-shaped,
The circularity is 0.36. The average circularity of Si particles of 0.50 or more means that the average circularity of Si particles of various shapes is 0.50 or more.

Si dispersed in the metal structure of the present invention
The size and shape of the particles are such that the equivalent circle diameter is 5.00 μm or less and the circularity is 0.50 or more, addition of Sr or Sb, suppression of Mn content, soaking, selection of extrusion conditions, etc. Thus, the particle size (equivalent circle diameter) and the shape (circularity) of the Si particles were controlled at the same time. The shape is angular even if the size (circle equivalent diameter) of the Si particles is controlled to 5.00 μm or less. And, cracks occur at the interface between the Si particles and the matrix, and the fatigue strength and toughness at high temperatures are reduced. If the size and shape of the Si particles are outside this range, the fatigue strength, toughness and bending strength are Because it will be inferior. It is more preferable that the Si particles have a circle equivalent diameter of 3.00 μm or less and a circularity of 0.50 or more.

2A and 2B are micrographs (× 400) showing the distribution (size and shape) of Si particles in the metal structure of the Al—Si alloy material. 2 (a) relates to the present invention (invention example No. 1 shown in Table 1), M
n0.01 wt%, equivalent circle diameter 2.85 μm, circularity 0.
62, and it can be seen that the Si particles are fine and rounded. 2B shows a conventional one (Comparative Example No. 21 shown in Table 3) having Mn of 0.08 wt%, a circle equivalent diameter of 3.91 μm, and a circularity of 0.35. However, the circularity does not satisfy the present invention, and it can be seen that the Si particles are slightly large and angular. The equivalent circle diameter and circularity of Si particles of the Al-Si alloy of the present invention are determined by the alloy composition (active addition of Sr or Sb and M
Controlling the addition of n amount), homogenization heat treatment conditions for the ingot billet, and hot extrusion processing, there is almost no change in the subsequent forging processing and heat treatment.

Further, according to the present invention, as described above, a material having controlled alloy composition and dispersion of Si particles in metal structure (equivalent circle diameter, circularity) is formed into a predetermined shape by forging after hot extrusion. After processing, the material that was finally quenched and age-hardened (T6
The material which has been subjected to artificial age hardening treatment after solution heat treatment) has high strength and high abrasion resistance, as well as fatigue strength at high temperature, toughness and bending strength. It is excellent.

Next, a method for manufacturing the wear resistant Al alloy for wrought of the present invention will be described. That is, according to the present invention, the Al alloy ingot billet having the above-described composition is homogenized and heat-treated at 480 to 540 ° C. for 2 hours or more, and then hot extrusion is performed, and the equivalent circle diameter of Si grains in the metal structure is 5.00 μm. The degree of circularity is 0.50 or more, and subsequently, after forging, quenching age hardening heat treatment (T6 treatment, solution heat treatment and artificial age hardening treatment) is performed.

Here, the homogenizing heat treatment at 480 to 540 ° C. for 2 hours or more is to disperse the microsegregation of the ingot or to form a solid solution of the precipitate of the additional element, and to form the plate-like or needle-like crystal of Si. This is to make the product finer and spherical. Temperature is 48
When the temperature is lower than 0 ° C. and the time is short, the effect is not obtained and the above-mentioned characteristics cannot be obtained. If the temperature is higher than 540 ° C, there is a risk of melting. Therefore, the homogenizing heat treatment of the ingot is performed within the above range. Although the time may be long, it is uneconomical and is preferably 16 hours or less.

After that, the hot extrusion is performed by the eutectic S of the ingot.
i is divided into fine particles, finely dispersed in a matrix, and Si particles in the metal structure have a circle equivalent diameter of 5.00.
This is because it is less than or equal to μm and the circularity is 0.50 or more. A similar metal structure can be obtained by performing hot rolling instead of hot extrusion.

Subsequently, forging and quenching age hardening heat treatment (T
The artificial age hardening treatment after the 6-treatment solution treatment is carried out to further improve the respective characteristics in a used state after being formed into a predetermined shape by forging, and in the alloy composition of the present invention, After holding at 490 ° C to 520 ° C for 30 minutes to 4 hours, water quenching, and then artificial aging treatment at 170 ° C to 190 ° C for 4 hours.
By performing quenching age hardening heat treatment for 16 hours, fatigue strength at high temperature, toughness, bending resistance, strength, and abrasion resistance are improved.

This is because the equivalent circle diameter and circularity of Si grains are
The alloy composition of the present invention (particularly Sr, Sb and Mn as an impurity are restricted to 0.04 wt% or less), the homogenizing heat treatment conditions of the alloy ingot billet, the hot extrusion process or the hot rolling, and the subsequent The equivalent circle diameter and circularity of Si grains hardly change during forging and heat treatment, and fatigue strength at high temperature,
It improves toughness, bending resistance, strength, wear resistance and the like.

The present invention is a wear-resistant Al alloy for wrought which has a specified alloy composition and a specified distribution of Si particles in its metal structure, and which has been subjected to quenching age hardening heat treatment after being formed by forging. It is characterized by being excellent in fatigue strength at high temperature, toughness, bending resistance, strength, abrasion resistance and the like, and it is preferable to use it after forming it into a scroll. Molding by the forging process is performed at a forging die temperature of 120 to 170 ° C. and a material temperature of 2
20-370 ° C, ram descent rate 200-800 mm / s
Under the condition of ec, it is formed by a single forging process using a cold forging lubricant containing MoS ₂ .

The forming by forging of the Al alloy scroll having the alloy composition of the present invention will be described. The temperature of the forging die is limited to 120 to 170 ° C. If the temperature is less than 120 ° C., the material is likely to crack, and the flow of the material becomes worse during forming by forging in the forging die. Also, 170
This is because if the temperature exceeds ° C, the dimensional accuracy and surface quality of the obtained molded product deteriorate. The material temperature during forging is 22
The reason why the material temperature is limited to 0 to 370 ° C. is that if the material temperature is lower than 220 ° C., forging is difficult, and if the material temperature exceeds 370 ° C., the microstructure after forging changes and the lubricating action of MoS ₂ becomes insufficient.

The ram descending speed is 200 to 800 mm / se.
The value of c is limited to less than 200 mm / sec, the temperature of the material is lowered, cracking of the material is likely to occur during forging, the flow of metal in the forging die is deteriorated, and 800 mm / sec.
This is because if it exceeds sec, the temperature rises due to the heat generated by the material processing and the structure after forging changes. Preferably, the ram lowering speed is 400 to 600 mm / sec. In addition,
The ram descent rate here means the processing rate of the upper die with respect to the lower die of the die which is a forging die. The scroll has a scroll-shaped scroll portion.

Although the scroll has a spiral shape and is complicated in shape, it can be formed by a single forging process because the material in which Si particles are finely dispersed is used and the condition as described above, that is, forging is used. Mold temperature 120-170 ℃, material temperature 220-370 ℃, ram descent speed 200-800m
By forming with a lubricant for cold forging containing MoS ₂ under the condition of m / sec, a force is transmitted to the inside of the material in the forging die, and a scroll having a complicated shape is formed. It is possible to obtain a scroll without any internal defects. Further, as the lubricant for cold forging containing MoS ₂ , a lubricant in which MoS ₂ is dispersed in oil or mineral oil is used.

Further, under the forging conditions as described above,
By forming a scroll of a wear-resistant Al alloy for wrought that specifies the dispersion of Si particles in the metal structure with the alloy composition of the present invention, there is no internal defect, excellent dimensional accuracy after forging, and the surface Also, because you can get a defect-free one,
It is possible to form a scroll of wrought wear-resistant Al alloy, which is free from the factors that affect the fatigue strength.

In the method of manufacturing an Al alloy scroll of the alloy composition of the present invention, the Al alloy ingot is made to be 480-5.
Homogenized heat treatment is performed at 40 ° C. for 2 hours or more, and then hot extrusion or hot rolling is performed to have a metal structure in which Si particles are finely dispersed, and the Si particles have an average equivalent circle diameter of 5.00 μm or less. The average circularity of 0.50 or more and the artificial age-hardening heat treatment at 170 ° C. to 190 ° C. for 4 to 16 hours have been described above.

[0040]

[Embodiment 1] A first embodiment of the present invention will be described with reference to Tables 1 to 4. Tables 1 and 2 are examples of the present invention, which are the results of evaluation of mechanical properties of the quench-age-hardened material (T6).
And Table 4 is a comparative example, and shows the results of evaluation of mechanical properties of the quench hardening age-hardened material (T6). In Tables 1 to 4, Al alloy ingots (diameter 220 mm) having the respective alloy compositions were manufactured by the semi-continuous casting method. This ingot billet was homogenized and heat-treated under the conditions of 480 to 520 ° C. × 4 to 12 hr shown in Tables 1 and 3, and then hot extruded at an extrusion temperature of 420 ° C. to obtain an extruded rod having a diameter of 80 mm.

This extruded rod was subjected to quenching and age-hardening heat treatment (T6) which was subjected to quenching and artificial age-hardening treatment in order to evaluate mechanical properties, high temperature fatigue strength and toughness, and abrasion resistance.
Material, which was subjected to artificial age hardening treatment after solution treatment). A test material was prepared from the material thus obtained as follows, and mechanical properties, high temperature fatigue strength, toughness, abrasion resistance, and transverse strength were determined by a test.

These test methods are as follows. (1) Mechanical properties JIS 4 round bar test pieces were used as the test pieces. The measurement items are tensile strength, proof stress and elongation. (2) Toughness (fracture strength property) For the test piece, the Charpy impact value was measured by the Charpy impact test method.

(3) Abrasion resistance test Using the Ogoshi type abrasion resistance tester, the specific abrasion amount of the test material was measured under the following conditions to evaluate the abrasion resistance. Lubrication condition: Gear oil (GL-5) Wear distance: Wet 200 mm Load: 19.7 kg Counterpart material: SCM21 Wear speed: 3.62 m / sec

(4) High temperature fatigue strength Using the Ono type high temperature rotating bending fatigue tester, the high temperature fatigue strength of the test material was evaluated under the following conditions. Test temperature: 150 ° C Repeat rate: 3600ppm Repeat number: 1 x 10 ⁷ times

(5) Bending test As shown in FIG. 3, the test piece (1) is supported by two supporting members (2).
And press the load in the direction of the arrow with the presser foot (3) to check the bending strength until the test piece (1) breaks and the arrow of the presser foot (3) until the test piece (1) breaks. The directional stroke was measured. The test piece (1) has a length of 350 mm and a diameter of 20.
mm, and the distance 1 of the support (2) is 300 mm. This bending test was carried out according to JIS Z2203, and the bending test piece was based on No. B.

The size (average circle equivalent diameter) and shape (average circularity) of the Si particles of the metal structure in which the Si particles are finely dispersed were measured with respect to the cross-sectional structure of the extruded material parallel to the extrusion direction. Specifically, as described above with reference to FIGS. 1 and 2, a microstructure photograph taken at 400 times with a metallurgical microscope is subjected to image analysis by an image analyzer to measure the size and shape of Si particles. Is shown.

[Table 1]

[Table 2]

[Table 3]

[Table 4]

Examples of the present invention shown in Tables 1 and 2 (Nos. 1 to 1)
2) indicates tensile strength (N /
mm ² ) ≧ 400, yield strength (N / mm ² ) ≧ 360, elongation value (%) ≧ 6.0, high temperature fatigue property (Kgf / mm ² ) ≧
18, toughness (Kg · m / cm ² ) ≧ 0.40, abrasion resistance (mm ² / Kg) ≧ 4.0, bending strength (Kgf) ≧ 80
0, bending stroke (mm) ≧ 25, with a good balance of mechanical properties as shown in the comprehensive evaluation as “excellent”, and excellent fatigue strength and toughness in the quenching age hardening heat treatment state T6. , Abrasion resistance Al for wrought with bending strength
It is clearly an alloy.

On the other hand, Table 3 showing the comparison with the present invention.
And Comparative Examples (Nos. 13 to 24) in Table 4 have any one of mechanical properties such as tensile strength, proof stress, elongation value, high temperature fatigue property, toughness, wear resistance, bending strength and bending stroke. The desired properties cannot be obtained, and the mechanical properties are not well-balanced as indicated by "poor" in the comprehensive evaluation. Specifically, Comparative Example No. In No. 13, the tensile strength, proof stress and high temperature fatigue strength are low and desired properties cannot be obtained. Comparative Example No. 14, No. In No. 15, high temperature fatigue properties, toughness, and bending strength are low. Comparative Example No. 16, No. In No. 17, high temperature fatigue characteristics and bending strength are low. Comparative Example No. In Comparative Example No. 18, the elongation is low. 19, no. In No. 20, high temperature fatigue characteristics and bending strength are low. Comparative example No. 21, no. 2
In Comparative Example No. 2, since the Mn content was high and the circularity was low, desired characteristics could not be obtained. 23, no. In No. 24, desired properties such as high temperature fatigue properties, toughness, and low bending strength cannot be obtained.

Next, Table 5 shows examples of heat treatment conditions of the manufacturing method of the present invention. Table 5 shows that after the forging process of the present invention, water quenching after holding at 490 ° C. to 520 ° C. for 30 minutes to 4 hours and then artificial aging treatment at 170 ° C. to 190 ° C.
It shows the quenching age hardening heat treatment performed for 16 hours. As shown in the invention examples (No. 25 to No. 28) of Table 5, those subjected to the solution hardening age-hardening treatment under the conditions of the present invention were mechanically treated as indicated by "excellent" in the comprehensive evaluation. It has well-balanced properties and can produce wear-resistant Al alloy for wrought which has fatigue strength, toughness, and transverse strength.

For comparison with Table 5, heat treatment of quenching age hardening treatment T6 was carried out after solution heat treatment outside the range of the conditions of the present invention. Hold at 480 ° C for 10 hours and then quench with water to 180 ° C
In the case of 8-hour aging treatment, desired properties were not obtained in tensile strength, proof stress, bending strength and bending stroke. 5
In the case where the heat treatment is performed at 40 ° C. for 2 hours, the crystal grains become coarse and the crystal grain boundaries are eutectic melted. Also, after holding at 505 ° C for 2 hours, water quenching, aging treatment at 170 ° C for 2 hours, or 5
The desired characteristics could not be obtained even by water quenching after holding at 05 ° C for 2 hours and aging treatment at 190 ° C for 20 hours.

[Table 5]

[0051]

Second Embodiment A scroll will be described according to a second embodiment of the present invention. Alloy composition is Si 11.51wt
%, Fe 0.15 wt%, Cu 3.43 wt%, Mg
0.60 wt%, Cr 0.08 wt%, Ti 0.
01 wt%, Ni 0.26 wt%, Sr 0.02w
An alloy of t%, Mn 0.01% by weight, and the balance Al was manufactured as an Al alloy ingot having a diameter of 220 mm by a semi-continuous forging method, homogenized at 495 ± 5 ° C. for 8 hours, and then extruded at a temperature of 420. An extruded rod having a diameter of 80 mm was prepared at 0 ° C. The metal structure of the extruded rod was one in which Si particles were dispersed, the average equivalent circle diameter of the Si particles was 5.00 μm or less, and the average circularity was 0.50 or more.

The extruded rod was annealed at 370 ° C. for 2 hours and then cut into a disc-shaped forging material having a unit weight of 300 g. For general cold forging oil for this forging material, M
A lubricant containing oS ₂ was applied and heated to 280 ° C. On the other hand, the MoS ₂ -based lubricant was applied to a scroll-shaped mold having a diameter of 80 mm and heated to 145 ° C. This mold consists of a lower mold and an upper mold. The lower mold heated to 145 ° C was charged with the forging material heated to 280 ° C by applying the lubricant, and heated to 120 ° C. The upper die was lowered and formed into a scroll by a single forging process. At this time, the descending speed of the upper die (ram descending speed) is 250 mm /
sec.

The shape of the scroll of this product is shown in FIG.
As shown in Fig. 3, a flange (12) having a diameter of 80 mm and a thickness of 10 mm has a triple scroll-shaped scroll portion (11) having a height of 13 mm and a width of 2 mm on one surface and a boss portion (not shown) on the other surface. Is to have. When the scroll was manufactured under such forging conditions, a product with good dimensional accuracy was obtained. The forged scroll was held at 495 ± 5 ° C. for 2 hours, water-quenched, and then subjected to artificial aging treatment at 180 ± 5 ° C. for 8 hours, which was subjected to T6 quenching age hardening heat treatment.

Tensile strength of scroll part of scroll 434 N / mm ² Proof strength 385 N / mm ² Elongation 6.0% Charpy value 0.367 Kg · m / cm ² Bending strength 1918 Kgf Bending stroke 1.54 mm High temperature fatigue strength (test temperature 150 ° C., repetition rate 3600 rpm, stress 15.0 Kgf / mm ² number of repetitions 2.58 × 10 ⁷ , high strength, high wear resistance, fatigue strength at high temperature, toughness, high resistance It was possible to obtain a scroll having a folding value and to use it stably for a long period of time.

[0055]

As described above, according to the wear resistant Al alloy for wrought of the present invention, it is possible to obtain high strength, high wear resistance, fatigue strength at high temperature, excellent toughness and high resistance. It has a folding value, high strength, high wear resistance, fatigue strength at high temperature,
This is an industrially remarkable effect that a scroll having toughness and a high bending strength can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating the shape of Si grains in the metal structure of an Al alloy.

FIG. 2 is a micrograph (× 400) showing the distribution (size, shape) of Si particles in the metal structure of an Al alloy, (a) relating to the present invention, and (b) showing a conventional one. is there.

FIG. 3 is a diagram showing a bending test.

FIG. 4 is a diagram showing a scroll shape.

[Explanation of symbols]

 1 Test piece 2 Support 3 Presser foot 11 Spiral scroll section 12 Scroll flange

Claims (8)

[Claims] 1. Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05 -0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% The balance is made of Al and unavoidable impurities, and is an Al alloy in which the Mn of the unavoidable impurities is restricted to 0.04 wt% or less,
It has a metal structure in which Si particles are finely dispersed, and the average equivalent circle diameter of the Si particles is 5.00 μm or less and the average circularity is 0.50 or more, which is excellent at high temperature in a quenching age hardening heat treatment state. A wear-resistant Al alloy for wrought which has fatigue strength, toughness, and transverse strength. 2. Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05 -0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Zn: 0.25 wt% or less An Al alloy in which the balance is Al and unavoidable impurities, and Mn of the unavoidable impurities is restricted to 0.04 wt% or less,
It has a metal structure in which Si particles are finely dispersed, and the average equivalent circle diameter of the Si particles is 5.00 μm or less and the average circularity is 0.50 or more, which is excellent at high temperature in a quenching age hardening heat treatment state. A wear-resistant Al alloy for wrought which has fatigue strength, toughness, and transverse strength. 3. Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05 -0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Ti: 0.1 wt% or less, and / or B: 0.05 wt
%, The balance is Al and unavoidable impurities, and Al whose Mn of the unavoidable impurities is regulated to 0.04 wt% or less
The alloy has a metal structure in which Si particles are finely dispersed, and the Si equivalent particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more. A wear-resistant Al alloy for wrought, which has excellent high temperature fatigue strength, toughness, and transverse strength. 4. Si: 8.0 to 13.0 wt% Fe: 0.1 to 0.5 wt% Cu: 1.0 to 5.0 wt% Mg: 0.4 to 1.5 wt% Cr: 0.05 -0.5 wt% Ni: 0.05-0.5 wt% Sr: 0.005-0.05 wt%, or Sb: 0.0
5 to 0.3 wt% Zn: 0.25 wt% or less Ti: 0.1 wt% or less, and / or B: 0.05 wt
%, The balance is Al and unavoidable impurities, and Al whose Mn of the unavoidable impurities is regulated to 0.04 wt% or less
The alloy has a metal structure in which Si particles are finely dispersed, and the Si equivalent particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more. A wear-resistant Al alloy for wrought, which has excellent high temperature fatigue strength, toughness, and transverse strength. 5. An Al alloy ingot is homogenized and heat treated at 480 to 540 ° C. for 2 hours or more, and then hot extrusion or hot rolling is carried out to have a metal structure in which Si particles are finely dispersed.
The i particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more, and are subsequently forged.
5. After holding at 0 ° C. to 520 ° C. for 30 minutes to 4 hours, water quenching, and then performing artificial aging treatment at 170 ° C. to 190 ° C. for 4 to 16 hours, quenching age hardening heat treatment is performed. A method for producing a wear-resistant Al alloy for wrought according to any one of 1. 6. A heat-hardening age hardening heat treatment after forming by forging.
A scroll made of the wear-resistant Al alloy for wrought according to any one of 1. 7. A forging die temperature of 120 when forming by forging.
~ 170 ° C, material temperature 220 to 370 ° C, ram descending speed 200 to 800 mm / sec, using a lubricant for cold forging containing MoS ₂ to form a single forging process. A scroll made of a wear-resistant Al alloy for expansion according to claim 6. 8. An Al alloy ingot is homogenized and heat treated at 480 to 540 ° C. for 2 hours or more and then hot extruded or hot rolled to have a metal structure in which Si particles are finely dispersed.
The i-particles have an average equivalent circle diameter of 5.00 μm or less and an average circularity of 0.50 or more.
˜170 ° C., material temperature 220 to 370 ° C., and ram descending speed 200 to 800 mm / sec, using a lubricant for cold forging containing MoS ₂ to form a single forging process. After holding at 490 ° C to 520 ° C for 30 minutes to 4 hours, water quenching, and then artificial aging treatment at 170 ° C to 19
The method for manufacturing a scroll made of wear-resistant Al alloy for wrought according to claim 6, which is excellent in dimensional accuracy after forging, characterized by performing quenching age hardening heat treatment for 4 to 16 hours at 0 ° C. .