JP2000239764A - Corrosion resistant brass alloy for metallic mold casting or for sand mold casting, metallic mold cast product or sand mold cast product, and corrosion resistant brass alloy for continuous casting or continuous cast product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a corrosion resistant brass alloy excellent in melting and casting properties, grinding property and abrasiveness as pretreatment for plating. SOLUTION: The corrosion resistant alloy for metallic mold casting and for sand mold casting and metallic mold case product and sand mold cast product are composed by wt.% of 64.0-68.0% copper, 0.3-1.0% tin, 0.5-1.0% nickel, 0.4-0.8% aluminum, 0.01-0.03% phosphorus, 2.0-3.0% lead and as the impurities, <=0.2% iron, <=0.02% silicon, <=0.1% antimony, <=0.005% chromium and <=0.01% manganese and the balance zinc. Further, as more desirably, boron is contained by wt.% of 5-10 ppm in the above compositions. Furthermore, a corrosion resistant brass alloy for continuous casting and for a continuous cast product includes 0.03-0.15 wt.% phosphorus in the above composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a corrosion-resistant brass alloy having excellent melting / casting properties, machinability and polishing properties as a pretreatment for plating.

[0002]

2. Description of the Related Art Brass-based JIS 3250C3604 alloy or C
The 3771 alloy, the JISH5120 CAC203 alloy, the bronze-based JISH5120 CAC406 alloy and the JISH5121 CAC406C alloy are widely used.

[0003] Further, Cu-Z having improved dezincification corrosion characteristics has been proposed.
n-Sn based JIS H3250 C4622 alloy or C4
641 alloy and Cu-Zn-Pb-Sn-Fe-Ni
There is an -Sb-P alloy (Japanese Patent Publication No. 61-58540).
Furthermore, not only corrosion resistance but also high mechanical properties Cu-Zn
-Mn-Fe-Al based JIS H5120 CAC30
1 alloy and JIS 5121 CAC301C alloy.

[0004]

SUMMARY OF THE INVENTION Brass JIS 32
50 C3604 alloy and C3771 alloy, and JISH
The 5120 CAC203 alloy is excellent in machinability, but has a drawback of dezincification corrosion. Bronze JIS
H5120 CAC406 alloy or JIS 5121CA
C406 alloy has excellent machinability and corrosion resistance, but has disadvantages of high melting temperature and high price.

[0005] JIS 3250 C4622 alloy or C4
The 641 alloy, the JIS 5120 CAC 301 alloy and the JIS 5121 CAC 301 C alloy have defects in that the dezincification corrosion resistance is insufficient and the machinability is poor.

[0006] Japanese Patent Publication No. 61-58540 has excellent machinability and anti-zinc corrosion resistance, but is inferior in dissolution and castability because it does not contain aluminum. Regardless, since the upper limit of iron content is high and there is no allowable upper limit of chromium and manganese impurities, hard spots are likely to occur, which may impair the polishing property as a pretreatment for plating.

As described above, the conventional alloys are not satisfactory in all of the machinability, anti-zinc corrosion resistance, abrasiveness as a pretreatment for plating, and cost.

The present invention has been made in view of the above circumstances, and has excellent machinability, dezincification corrosion resistance, polishing ability as a pretreatment for plating, and good melting and casting properties and relatively inexpensive corrosion resistance. It aims to provide brass alloy ingots, molds, sand molds, and continuous castings.

[0009]

The weight ratio is 64.0-6.
8.0% copper, 0.3-1.0% tin, 0.5-1.0.
% Nickel, 0.4-0.8% aluminum,
It contains 0.01 to 0.03% of phosphorus and 2.0 to 3.0% of lead, and contains iron as impurities of 0.2% or less and silicon as 0.02%.
Below, 0.1% or less of antimony and 0.005% of chromium
The present invention relates to a corrosion-resistant brass alloy for mold casting or sand casting, or a mold or sand casting, wherein manganese is 0.01% or less and the balance is zinc.

Also, 64.0 to 68.0% by weight of copper, 0.3 to 1.0% of tin, 0.5 to 1.0% of nickel, and 0.4 to 0.5% by weight. 8% aluminum and 0.01 to 0.0
Contains 3% of phosphorus, 2.0 to 3.0% of lead and 5 to 10 ppm of boron, and contains iron as impurities of 0.2% or less, silicon of 0.02% or less, and antimony of 0.1%. Hereinafter, the present invention relates to a corrosion-resistant brass alloy for mold casting or sand casting, or a mold casting or a sand casting, wherein chromium is 0.005% or less, manganese is 0.01% or less, and the balance is zinc. Things.

Further, according to the first and second aspects, the present invention relates to a corrosion-resistant brass alloy for continuous casting or a continuous cast product, wherein the content of phosphorus is 0.03 to 0.15% by weight. It is.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention (how to implement the invention) which is considered to be preferable will be briefly described with reference to the operation and effect thereof.

According to the present invention, copper having a weight ratio of 64.0 to 68.0% is used in order to improve the melting and casting properties, and to improve the dezincification corrosion resistance and the polishing and machinability as a pretreatment for plating. When,
0.3-1.0% tin, 0.5-1.0% nickel,
0.4-0.8% aluminum and 0.01-0.03%
Of phosphorus and 2.0 to 3.0% of lead, iron as impurities is 0.2% or less, silicon is 0.02% or less, antimony is 0.1% or less, and chromium is 0.005%. Hereinafter, the present invention provides a corrosion-resistant brass alloy containing 0.01% or less of manganese and a balance of zinc. When 5 to 10 ppm of boron is added to the alloy, a corrosion-resistant brass alloy having the above-mentioned characteristics is further provided. can do.

Further, of the above alloys, phosphorus is added in a weight ratio of 0.1.
By setting the content to 03 to 0.15%, the machinability is reduced, but it is possible to provide a continuously cast corrosion-resistant alloy having improved dezincification corrosion resistance.

Next, the reasons for specifying the chemical components, their addition amounts, and impurity amounts in the alloy of the present invention as described above will be described.

Copper (Cu: 64.0 to 68.0% by weight) Copper is made 64.0% or more in order to bring the alloy structure of brass closer to the α single phase and to improve the dezincification corrosion resistance. The tensile strength was set at 68.0% or less in order to suppress the decrease in hardness and economical efficiency.

Tin (Sn: 0.3 to 1.0% by weight) Tin is added to improve the dezincification corrosion resistance of the brass alloy. The addition of tin further improves the dezincification corrosion resistance in combination with the improvement of the dezincification corrosion resistance by the addition of nickel, aluminum, and phosphorus, which will be described later. In consideration of economical efficiency and suppression of deterioration in corrosion resistance and machinability due to brittle γ-extrusion during cooling, the content is set to 1.0% or less.

Nickel (Ni: 0.5 to 1.0% by weight) Nickel has a function of increasing the α-phase structure of the brass alloy, and improves the dezincification corrosion resistance and mechanical properties. Nickel improves dezincification corrosion resistance by a synergistic effect with tin. In order to ensure the effect of improving the dezincification corrosion resistance and mechanical properties, the content is made 0.5% or more. Considering economy, it was reduced to 1.0% or less.

Aluminum (Al: 0.4-0.8% by weight) Aluminum is added to improve the melting and casting properties of brass alloys and to improve mechanical properties and dezincification corrosion resistance. Considering the economics to ensure the effect and 0.4
% Or more. If the addition amount of aluminum is excessively increased, not only is the dezincification corrosion resistance reduced, but also the mechanical properties such as elongation and impact value are reduced, and the machinability is also reduced. I made it.

Phosphorus (P: 0.01-0.03% by weight) Phosphorus, in combination with tin and aluminum, improves the dezincification corrosion resistance and combines with nickel and impurity iron,
Added to improve dezincification corrosion resistance, but 0.01
There is no effect if it is less than%. To prevent a decrease in machinability,
0.03% or less.

In the alloy for continuous casting and the continuous casting, the content of phosphorus is made 0.03 to 0.15% by weight in order to improve the continuous castability and to further improve the dezincification corrosion resistance. , Phosphorus is preferably 0.03% or more.
In order to suppress an increase in intergranular corrosion susceptibility and a decrease in machinability due to an increase in deposits, 0.15% or less is preferable.

Lead (Pb: 2.0-3.0% by weight) Lead is necessary for improving the machinability of the brass alloy, and when the added amount is 2.0% or more, the machinability is good. If it exceeds 3.0%, the tensile strength, elongation and impact value decrease.

Boron (B: 5 to 10 ppm) Although boron is relatively expensive, it refines the crystal structure of the brass alloy, improves the dezincification corrosion resistance, improves the mechanical properties, and improves the pretreatment for plating. It is added to improve polishing properties. If the amount of boron is less than 5 ppm, the effect is small, and if it exceeds 10 ppm, the risk of generation of hard spots increases.

Impurity iron (Fe ≦ 0.2% by weight) Iron has a crystal refining action of a brass alloy, but as the content increases, the formation of a compound with phosphorus increases, so that the susceptibility to intergranular corrosion increases and the iron content increases. In order to cause a reduction in machinability, the content is set to 0.2% or less.

Impurity silicon (Si ≦ 0.02% by weight) Since silicon has a high Zn equivalent and a high effect of increasing the β phase structure of the brass alloy, the content of silicon is set to 0.02% or less.

Antimony impurity (Sb ≦ 0.1% by weight) Antimony has an effect of improving the dezincification corrosion resistance of a brass alloy, but has an effect of making the brass alloy brittle and hard, so that 0.1% or less. I made it.

Manganese impurity (Mn ≦ 0.01% by weight) Manganese has a tendency to form brittle intermetallic compounds with other impurities such as iron and silicon, and has a machinability and a polishing property as a pretreatment for plating. Therefore, the content was set to 0.01% or less.

Impurity chromium (Cr ≦ 0.005% by weight) Chromium forms brittle intermetallic compounds alone or with other impurities such as iron, and significantly impairs machinability and polishing properties as a pretreatment for plating. Therefore, it is necessary to make the content 0.01% or less, but in order to further ensure the content, the content is made 0.005% or less.

With the above construction, (1) excellent dezincification corrosion resistance without impairing mechanical properties by increasing the copper content and adding tin, nickel, aluminum and phosphorus in predetermined amounts. Nature can be secured.

(2) By optimizing the lead content, excellent machinability can be ensured without impairing the mechanical properties.

(3) The contents of impurities such as iron, silicon, manganese and chromium which cause the formation of hard spots are limited to a minute amount, and the upper limits are set for the contents of tin, aluminum and phosphorus which are effective alloy components. As a result, the machinability and the polishing property as a pretreatment for plating can be improved.

(4) By making the aluminum content appropriate, the melting and casting properties can be improved.

Further, by adding a certain amount of boron to the above-mentioned corrosion-resistant brass alloy having excellent melting / casting properties, machinability and polishing properties, more excellent mechanical properties, dezincification corrosion resistance and polishing can be obtained. Nature can be secured.

[0034]

EXAMPLES Specific examples of the present invention will be described.

(1) Examples of the present invention (corrosion-resistant brass alloys belonging to the present invention) are shown in Table 1 attached as FIG. 1, and comparative examples (including conventional alloys) are shown in Table 2 attached as FIG.
It was shown to. Of the alloys consisting of Nos. 1 to 27 shown in Tables 1 and 2, except for Nos. 21, 22, and 23, were melted in a graphite crucible electric furnace, and were subjected to JIS5
Die casting on 120E test material and φ50mm × 2
It was cast into a 20 mmL carbon mold to obtain a test material of the present invention and a test material of a comparative example. For Nos. 21, 22, and 23, commercially available extrusion rods were used as test materials.

(2) Mechanical Property Tests The tensile strength, proof stress, and elongation tests were performed by machining each of the test materials in Tables 1 and 2 into JISZ22014 tensile test pieces. The hardness test was performed on each test material in the form of a column, and on the processed plane. The results are shown in Table 3 attached as FIG. 3 and Table 4 attached as FIG.

(3) Machinability test In the machinability test, each of the test materials shown in Tables 1 and 2 was Φ25 mm
After machining to × 50 mmL, the outer diameter portion was cut and machined using a cutting tool having the shape shown in FIG. 8 under the conditions shown in Table 5 attached as FIG. The machinability was evaluated from the shape of the cutting powder generated at the time of machining as shown in Table 6 attached as FIG. 6, and the results are shown in Tables 3 and 4. In the drilling test, each test material was processed into a columnar shape, and the processing plane was drilled under the drilling conditions shown in Table 7 attached as FIG.
The hole was drilled to a depth of 5 mm, and the drilling was performed. The drilling workability was determined by measuring the time required for the drilling, and the results are shown in Table 3.
And Table 4 below.

(4) Corrosion test In the corrosion test, each of the test materials shown in Tables 1 and 2 was measured for φ10 mm ×
After machining to 20 mmL, it was carried out based on the dezincification corrosion test method of ISO6509, and the corrosion weight loss rate and the maximum depth of the dezincification layer were measured. The results are shown in Tables 3 and 4.

(5) Hot workability test The hot workability test was performed by testing each of the test materials shown in Tables 1 and 2 for φ25 m.
After machining to mx 25mmL, 2 at 650 ± 10 ° C
Heated for 0 minutes, 15 tons per 100 mm ^{2 of} forged material
Forging was performed, and the forging deformation rate and the presence or absence of forging cracks were measured. The results are shown in Tables 3 and 4.

(6) Abrasiveness test The abrasionability test was conducted by using each of the test materials shown in Tables 1 and 2 at 1200 mm.
After machining to ² or more × 15 to 30 mmL, the surface was polished with a buffing grinder, and the presence or absence of surface defects such as hard spots, soft spots, and obiki (also called comet) was measured. The results are shown in Tables 3 and 4.

From these test results, it can be confirmed that the intended object of the present invention can be achieved.

[0042]

Since the present invention is constructed as described above, the present invention has improved melting and casting properties, and has improved dezincification corrosion resistance and improved abrasiveness and machinability as a pretreatment for plating. It is possible to provide a corrosion-resistant brass alloy for casting, a mold casting or a sand casting.

According to the second aspect of the present invention, since 5 to 10 ppm of boron is further contained, a corrosion-resistant brass alloy or a mold casting or a sand casting for mold casting or sand casting with further improved characteristics is used. It can be provided.

That is, the present invention provides: (1) By increasing the copper content and adding a predetermined amount of tin, nickel, aluminum and phosphorus, excellent dezincification corrosion resistance can be obtained without impairing mechanical properties. Can be secured.

(2) By setting the lead content appropriately, excellent machinability can be secured without impairing the mechanical properties.

(3) The contents of impurities such as iron, silicon, manganese and chromium, which cause the formation of hard spots, are limited to a very small amount, and the upper limits are set for the contents of tin, aluminum and phosphorus as effective alloy components. As a result, the machinability and the polishing property as a pretreatment for plating can be improved.

(4) By making the aluminum content appropriate, the melting and casting properties can be improved.

Further, by adding a certain amount of boron to the above-mentioned corrosion-resistant brass alloy having excellent melting / casting properties, machinability and polishing properties, more excellent mechanical properties, dezincification corrosion resistance and polishing can be obtained. Nature can be secured.

According to the third aspect of the invention, by making the weight ratio of phosphorus in the above alloy 0.03 to 0.15%, the machinability is reduced, but the dezincification resistance is further improved. Thus, it is possible to provide a corrosion-resistant brass alloy for continuous casting or a continuous cast product having improved properties.

[Brief description of the drawings]

FIG. 1 illustrates Table 1.

FIG. 2 illustrates Table 2.

FIG. 3 illustrates Table 3.

FIG. 4 illustrates Table 4.

FIG. 5 illustrates Table 5.

FIG. 6 illustrates Table 6.

FIG. 7 illustrates Table 7.

FIG. 8 is an explanatory diagram showing a cutting tool in a machinability test in the present embodiment.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Funami 2-17-2 Kida, Joetsu City, Niigata Prefecture Inside Joetsu Material Co., Ltd. (72) Inventor Hiroshi Shimada 2-17-2 Kida, Joetsu City, Niigata Prefecture Joetsu Material Co., Ltd. (72) Inventor Katsuyuki Nakajima 2-17-2 Kida, Joetsu City, Niigata Prefecture Joetsu Material Co., Ltd.

Claims (3)

[Claims] 1. 64.0% to 68.0% by weight of copper,
0.3-1.0% tin, 0.5-1.0% nickel,
0.4-0.8% aluminum and 0.01-0.03%
Of phosphorus and 2.0 to 3.0% of lead, iron as impurities is 0.2% or less, silicon is 0.02% or less, antimony is 0.1% or less, and chromium is 0.005%. In the following, a corrosion-resistant brass alloy for mold casting or sand casting, or a mold or sand casting, wherein manganese is 0.01% or less and the balance is zinc. 2. 64.0 to 68.0% by weight of copper,
0.3-1.0% tin, 0.5-1.0% nickel,
0.4-0.8% aluminum and 0.01-0.03%
Phosphorus, 2.0 to 3.0% of lead and 5 to 10 ppm of boron, iron as an impurity is 0.2% or less, and silicon is 0.0% or less.
2% or less, antimony 0.1% or less, chromium 0.00
Corrosion-resistant brass alloy or mold casting or sand casting for mold casting or sand casting, characterized in that 5% or less, manganese is 0.01% or less, and the balance is zinc. 3. The corrosion-resistant brass alloy or continuous cast product for continuous casting according to claim 1, wherein the content of phosphorus is 0.03 to 0.15% by weight.