JP2891025B2 - Slipper metal for rolling mill - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slipper metal for a rolling mill using a wear-resistant aluminum bronze alloy.

[0002]

2. Description of the Related Art Abrasion-resistant copper alloys such as aluminum bronze, high-strength brass, bronze, and phosphor bronze are used for sliding parts in various industrial machines. This is because, when the members composing the sliding part are carbon steel, Cr-Mo steel, steel for mechanical structure such as hardened steel, or tool steel such as bearing steel and high speed steel, wear due to sliding is large. It is because it becomes. Further, copper alloys are properly used according to the characteristics required for components.

[0003] For example, gears and worm wheels which require hardness and mechanical strength are made of high-strength brass or aluminum bronze, and bronze or phosphor bronze are used for bearings which are required to be resistant to seizing and galling. Used. Further, from the demand for high strength and high wear resistance, Cu-Z
An Mn-Si compound crystallized and dispersed in an n-based alloy (Japanese Patent No. 882216), and a Fe-Si compound crystallized and dispersed in a Cu-Al-based alloy (Japanese Patent No. 1189793) have been proposed. . However, these cannot be said to be sufficient as wear-resistant copper alloy parts, and the appearance of alloy parts having higher performance is desired.

Further, as a die material for cold working of an active metal such as stainless steel or titanium, a high-hardness abrasion-resistant aluminum bronze alloy (Japanese Patent No. 1374020) has been proposed. It contains hypereutectoid Al (12% or more), and
Since it has a high Mn composition (Mn: 6% or more), the elongation of mechanical properties (elongation percentage is about 3% or less) is small, and it is not suitable for a sliding member of industrial machinery.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a slipper metal for a rolling mill using an aluminum bronze alloy having both high toughness (elongation of 5% or more) and high wear resistance. .

[0006]

The gist of the present invention to achieve the above object is to realize high toughness and high wear resistance by crystallizing and dispersing a Mn-Si compound in a Cu-Al alloy. Al: 7 to 12%, Mn: 1.5 to 5.5% by weight,
Si: 0.4 to 2.7%, impurity: 0.5% or less, the balance being substantially Cu, the intermetallic compound of Mn and Si is dispersed, and the amount of solid solution Si is 0.1 to 1%. % Of a slip alloy for a rolling mill, characterized in that the slipper metal is made of a cast alloy.

In particular, it is desirable that the ratio of Mn to Si is 1-32. The alloy contains Zn: 2% or less and Pb: 1%.
%, One or more of Cr, V, Ti, Zr in total of 1%
In the following, impurities can be contained at 0.5% or less (mainly Fe, Ni).

[0008]

The Cu-Al alloy is generally referred to as aluminum bronze and has excellent properties against abrasive wear, but has a drawback that it is liable to adhere and easily seize. However, the alloy having the composition of the present invention can solve this problem. This is because the Mn-Si compound is crystallized in the solid solution of the Cu-Al alloy and has a high resistance to abrasion.

The above-mentioned effects of the Mn-Si compound are expressed by Cu
It is important to consider the following points in order to effectively exert the effect on -Al alloys.

[0010] 1. The Mn-Si compound crystallizes in the solid solution during the process of solidifying the molten Cu alloy.
When the Si compound is in the hypereutectic composition region (region existing as a primary crystal), the wear resistance is improved.

2. Since the elongation of the alloy decreases with an increase in the amount of the Mn-Si compound, the amount of addition in which the hypereutectic composition region is obtained is minimized.

3. Crystallized Mn-Si compound is a rod in the Cu-Zn based alloy (Compound Structure: hexagonal Mn ₅ Si ₃₎
However, in order to prevent a reduction in the elongation of the alloy, the alloy is crystallized in a lump and refined.

Next, the composition of the alloy of the present invention and its quantitative range will be described.

(1) Al The Al content is closely related to the strength of the alloy, and is preferably 7 to 12%.
If it is less than 7%, the target strength as a machine component does not satisfy 40 kgf / mm ² as cast, and if it exceeds 125, a γ ₂ phase is precipitated and becomes brittle, making it unsuitable for practical use as a machine component. Especially 7 to 11%, most 7.0 to 9.0% to 7.
8 to 8.5% is preferred.

(2) Mn and Si Mn and Si are uniformly dispersed in the alloy structure as a Mn-Si compound and are essential elements for improving wear resistance. In particular, the compound crystallized in the Cu-Al solid solution has a stoichiometric composition of Mn ₅
It turned out to be close to Si ₃ . This compound has a weight ratio of Mn: Si ≒ 3.25: 1. In order to improve the wear resistance, it is desired that the Mn-Si compound be crystallized as primary crystals. In the case of a Cu-Al alloy, the required amount of the Mn-Si compound is 2% or more, and pure Cu, Cu-Sn , Cu-Zn
The amount of addition may be relatively small compared to 24%, 10% and 3% of the alloy. In the present invention, Mn is 1.5 to 5.5%,
Si may be 0.45 to 2.7%. In particular, from both aspects of tensile strength and wear resistance, Mn is 3.8 to 5.4% to 4.
3 to 5.4% and Si is 1.0 to 2.0% to 1.3 to
1.6% is preferred. The wear resistance improves with the amount of the Mn-Si compound, but if it exceeds 7.2%, the elongation of the alloy cannot reach the target of 5%. Therefore, Mn is 5.5%
In this case, Si may be 1.7% or less. However, Mn-S
Inclusion of 0.1% or more and 1% or less of Si (solid solution Si) in excess of the amount necessary for the formation of the i-compound (Mn ₅ Si _{3 of} stoichiometric composition) is advantageous for improving wear resistance and strength. Works.
Therefore, the present invention can contain up to 2.7% of Si.

Further, the composition ratio of Mn to Si is determined by the relationship between the formation of a Mn-Si compound and the amount of solid solution Si, and the ratio of Mn / Si
Is preferably 2.0 to 3.0 from 1 to 3.25. In particular, S
Since the solid solution amount of i lowers the elongation percentage, it is assumed that the whole forms Mn ₅ Si ₃ , and the value obtained by calculation assuming that the remaining Si forms a solid solution is 1.0% or less. In particular, 0.01 to 0.1.
6% is preferable, 0.1 to 0.6% is more preferable, and 0.3 to 0.5% is most preferable.

(3) Pb The addition of Pb improves seizure resistance and machinability, and is particularly effective in ensuring wear resistance under conditions in which lubricating oil is easily removed. The addition amount of 1% or less is sufficient, and if it is more than 1%, the mechanical strength of the alloy is reduced. Therefore, 0.2 to 0.6% is preferable.

(4) Zn Zn has a degassing effect on the molten metal during the melting operation, and also has an effect of improving the molten metal flow during casting. Furthermore, there is an effect of improving the conformability of the alloy under sliding, but if it exceeds 2%, the sliding characteristics are reduced. Therefore, 0.5 to 1.5
% Is preferred. (5) Cr, V, Ti and Zr Cr, V, Ti and Zr coexist with Si to form a compound (silicide). These elements have the effect of increasing the strength, and Cr and V have the effect of making the Mn-Si compound finer. However, if the total amount exceeds 1%, the toughness is reduced. 0.05-0.5% is preferable.

(6) Fe and Ni Fe and Ni are acceptable if they are 0.5% or less as impurities. In particular, Fe has the effect of forming a solid solution in the Mn-Si compound to refine the compound. However, when the amount exceeds the above-mentioned allowable amount, a Fe-Si compound having a high melting point is generated, and castability is deteriorated. Further, since Ni has an effect of suppressing the generation of the Mn-Si compound, it is preferable that Ni is small. As an impurity, 0.01 to 0.1% is preferable.

The aluminum bronze alloy of the present invention is produced by a melting casting method in the same manner as a general aluminum bronze alloy. However, in the atmospheric dissolution method, since gases such as oxygen and hydrogen are involved in the molten metal, slag is removed before tapping, and argon gas, nitrogen gas, Ar gas or a mixed gas of nitrogen gas and fluoride (for example, N ₂ + NaF) is used. After performing bubbling for degassing the molten metal by gas, casting is performed.
As a result, a casting free from forging defects can be obtained. Casting can be performed using a mold such as a mold or a sand mold, or a semi-finished product such as a rod, a hollow pipe, or a plate can be obtained by a continuous casting method.

On the other hand, it is significant to perform forging and further extruding after casting.
A semi-finished product in which the n-Si compound particles are miniaturized is obtained. The size of the Mn-Si compound particles of the molten cast alloy is
It mainly depends on the cooling rate in the temperature range equal to or higher than the solidification completion temperature, and the slower the cooling rate, the larger the particles tend to be.
The alloy of the present invention is subjected to heat treatment to have a tensile strength of 400 N / mm ² or more, an elongation of 10% or more, and a hardness of H _B
When it is 120 or more, the mechanical strength, abrasion resistance and the like can be improved.

[0022]

EXAMPLES (Example 1) Table 1 shows an example of the composition of the alloy according to the present invention, and Table 2 shows its mechanical properties. Among the alloys, Nos. 1-3, 5, and 6 are comparative examples, and Nos. 4, 7-9 are alloys according to the present invention.

[0023]

[Table 1]

[0024]

[Table 2]

The melting procedure is as follows. Taking the basic alloy No. 4 as an example, Cu is first melted, then Mn and Si are added, and finally, Al is melted.
Was added to make a homogeneous molten metal. Then, nitrogen gas is blown into the slag and the molten metal to perform degassing by bubbling.
It was cast into a previously formed sand mold and solidified. The casting temperature was 1150 ° C., the melting furnace was an Elema furnace, and the crucible was graphite. The size of the ingot is 50mm in diameter x 200mm in length
And weighs about 3 kg. The alloy of this embodiment is basically an alloy in which a Mn-Si compound is uniformly dispersed in a Cu-Al alloy. This is an elongation of 5% for the toughness required for power transmission mechanisms and sliding mechanism members of various industrial machines.
The above values were satisfactory.

Looking at the relationship between the amount of dissolved Si and the tensile strength from Table 2, Nos. 1-3, 5, and 6 having less than 0.1% of dissolved Si have low strengths, and the present invention has a low strength. The amount of dissolved Si according to
It is clear that those with 1% or more have high tensile strength.

FIG. 1 shows the Mn / Si alloy of the present embodiment.
While changing the ratio in the range of 1.96 to 3.10, Mn ₅
Calculated as Si _{3 and} assuming the amount of solid solution Si to be about 0.2%
The relationship between the Mn content and the elongation of a casting in which a Mn-Si compound is crystallized and dispersed by adding to Cu-9% Al is shown.

As is apparent from FIG. 1, the elongation decreases as the Mn content increases. In particular, if the Mn content exceeds 5.5%, the elongation percentage is not satisfied with 5%. Therefore, it is necessary to select the power transmission and the application to the sliding mechanism members by carefully observing the characteristics of the material.

As a result of observing a typical microstructure of the alloy of the present embodiment, a massive Mn-Si compound was uniformly dispersed in a two-phase base material having an α phase on a white background and a β phase on a black background.
Many particles of the -Si compound having a size of 20 to 30 m were observed.

The effect of the added element on the structure is as follows.
In the case of Zn, the β phase increases like Al, and Cr, V, T
In the case of i and Zr, the Mn-Si compound tends to be fine. In the case of Pb, there is no change in the structure, and it does not form a solid solution in the substrate, so that it is dotted in a size of several μm or less.

From the ingot obtained in this example, 30 mm × 30
A plate sample of mm × 5 mm was collected, and the seizure resistance of the alloy was evaluated without lubrication. The evaluation method used a bearing steel ball (SU
J-2, diameter 10 mm), perform a reciprocating friction test at a speed of 8 mm / s. Was evaluated. Here, the reciprocation was 40 mm / 1 stroke, and when no change was observed in the friction coefficient even after sliding 200 times with a load of 100 kg, the load was sequentially increased to 200 g and 300 g for measurement.

FIG. 2 shows the evaluation results of the seizure resistance of the alloy. General aluminum bronze alloy No.1 (JIS AL
BC2) and a wear-resistant high-strength brass alloy No. 2 in which a Mn-Si compound is dispersed in a Cu-Zn-based alloy have a load of 100 kg.
Occurred in the initial stage of friction. For these comparisons,
The alloys No. 4 to No. 7 of this embodiment show excellent seizure resistance.

FIG. 3 shows the wear resistance of the alloy in oil. For this measurement, a cylindrical fixed specimen having a diameter of 10 mm and a length of 25 mm was prepared from a copper alloy, and this was pressed onto a movable piece made of 120 mm x 15 mm x 10 mm carbon steel (JIS S45C).
The alloy was slid reciprocally in turbine lubricating oil, and the wear amount of the alloy with respect to the friction distance was measured. The surface pressure was 500 kgf / cm ² and the sliding speed was 0.2 m / s.

The abrasion resistance of the aluminum bronze alloy (No. 4, No. 8) according to the present invention in which the Mn-Si compound is dispersed is determined by the general aluminum bronze alloy (No. 1) and the wear-resistant high-strength brass. It far exceeded the alloy (No. 2). As a sliding member, even if the abrasion of the sliding partner material can be reduced, it leads to a long life. The wear amount of the mating material having a total No. 1 of the comparative example was 10 mg at a friction distance of 5 km, whereas the wear amount of No. 4 of the present embodiment was about ２ ， of the above No. 1 and N
In the case of o.8, it was also found that the reduction was remarkably reduced to about 1/5.

FIG. 4 is an assembly diagram in which the aforementioned alloy No. 8 according to the present invention is used as a slipper metal for a rolling mill of an iron making machine. 5 and 6 are a front view and a plan view of the slipper metal. A guide metal for a work roll of a rolling mill was manufactured in the same manner, and compared with conventional high-strength brass or bronze, the frequency of replacement was 1/2 or less of the conventional frequency. In particular, where cooling water exists in a sliding environment, it was effective as a component with little wear.

[0036]

The slipper metal for a rolling mill comprising the aluminum bronze alloy of the present invention is a conventional aluminum bronze,
Compared to a wear-resistant copper alloy in which a Mn-Si compound is dispersed in a Cu-Zn-based alloy, the alloy has an excellent elongation rate of 5% or more and high wear resistance. Therefore, the life of the slipper metal for a rolling mill can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a graph showing the relationship between the Mn content and the mechanical elongation of the aluminum bronze alloy according to the present invention.

FIG. 2 is a bar graph showing seizure resistance in a sliding test under no lubrication.

FIG. 3 is a graph showing a relationship between a friction distance and a wear amount in a wear resistance test in oil.

FIG. 4 is a perspective view showing a combined state in which a motor and a roll of a rolling mill are combined.

FIG. 5 is a front view of the slipper metal.

FIG. 6 is a plan view of the slipper metal.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Tadashi Kainuma ▲ 2, 832 Horiguchi, Katsuta-shi, Ibaraki Pref. Hitachi, Ltd. Inside the Shaped Materials Division (72) Inventor Masaru Sakakura 832-Horiguchi, Katsuta-shi, Ibaraki (2) Inventor Masaki Suwa 4-6-6 Kanda Surugadai, Chiyoda-ku, Tokyo Inside Hitachi, Ltd. (72) Inventor Mitsuo Chizaki 7-omikamachi, Hitachi City, Ibaraki Prefecture No. 1 Hitachi, Ltd. Hitachi Research Laboratory (56) References JP-A-51-47518 (JP, A) JP-A-51-71819 (JP, A) JP-A-2-50928 (JP, A) No. 53-47209 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) C22C 9/00-9/10 B21B 35/14 C22C 1/00

Claims (5)

(57) [Claims] (1) Al: 7 to 12% by weight, Mn: 1.5 to 5% by weight
5.5%, Si: 0.45 to 2.7%, and the balance substantially consisting of Cu, the intermetallic compound of Mn and Si is dispersed, and the amount of solid solution Si is 0.1 to 1%. A slipper metal for a rolling mill, comprising a certain casting alloy. 2. Al: 7-12% by weight, Mn: 3.8-% by weight.
5.4%, Si: 0.45 to 2.7%, and the balance substantially consisting of Cu, in which the intermetallic compound of Mn and Si is dispersed and the amount of solid solution Si is 0.1 to 1%. A slipper metal for a rolling mill, comprising a certain casting alloy. 3. Al: 7 to 12% by weight, Mn: 1.5 to 5 by weight
5.5%, Si: 0.45 to 2.7%, and the balance substantially consisting of Cu, the Mn / Si ratio is 1 to 3.25, and the intermetallic compound of Mn and Si is dispersed. A slipper metal for a rolling mill, comprising a cast alloy having a solid solution Si content of 0.1 to 1%. 4. Al: 7 to 12% by weight, Mn: 1.5 to 5 by weight
5.5%, Si: 0.45 to 2.7%, Zn: 2% or less,
Pb: 1% or less, one or more of Cr, V, Ti, Zr in total of 1% or less, and the balance substantially consisting of Cu;
a cast alloy having an n / Si ratio of 1 to 3.25, an intermetallic compound of Mn and Si dispersed therein, and a solid solution Si content of 0.1 to 1%. Slipper metal. 5. Al: 7-12% by weight, Mn: 3.8-by weight
5.4%, Si: 0.45 to 2.7%, Zn: 2% or less,
Pb: 1% or less, one or more of Cr, V, Ti, Zr in total of 1% or less, and the balance substantially consisting of Cu;
Characterized by a cast alloy having an / Si ratio of 1 to 3.25, an intermetallic compound of Mn and Si dispersed therein, and a solid solution Si content of 0.1 to 1%. metal.