JPH1046364A - Brass material, its production, brass product, its production, faucet fitting parts and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brass material excellent in corrosion resistance and in which the hot workability of αbrass is remarkably improved, particularly, the one usable most suitably for a faucet fitting, and its method to produce faucet fitting parts. SOLUTION: The surface of α brass is coated with a metal forming β phases or α+β phases, which is subjected to diffusing treatment under heating to form a layer of β phases or α+β phases on the surface of the α brass. Furthermore, a brass material 1 in which the surface of α brass is applied with a layer in which β phases or α+βphases are formed is subjected to hot forging, thereafter, the layer in which β phases are formed on the surface is removed, by which the brass product excellent in corrosion resistance can be produced. Moreover, cold working is executed after the hot forging, by which the surface roughness can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface modification of a brass material, and more particularly to a brass material excellent in hot workability which can be suitably used as a faucet fitting, a method for producing the same, and a faucet fitting part. The present invention relates to a brass product and a method for producing the same.

[0002]

2. Description of the Related Art Various faucet fittings such as a single faucet and a hot and cold water faucet are commercialized after casting brass or bronze, hot forging, and machining such as cutting. Brass materials frequently used in the manufacture of such faucet fittings include α + β brass and α brass.

[0003] α + β brass is considered to be suitable as a material for faucet fittings, for example, because it is less expensive than bronze, is relatively soft and easily deformed, and has excellent hot workability. In general, a low pressure member on the secondary side, which is downstream from the valve because of its low pressure resistance, is used. Then, in the manufacturing process, in order to easily forge a semi-finished product (for example, a bar) after casting, for example, after heating and holding at a temperature of about 700 ° C. to increase the β phase, hot forging is performed.
After this, α-phase annealing is further performed.

[0004] In such a manufacturing process, brass material is heated to reduce deformation resistance, and β brass is used to improve workability in hot forging in a subsequent process and facilitate forging. It is intended to increase.
And, in the α-phase annealing, the corrosion resistance is degraded when the β-phase brass increases, so after hot forging, the α-phase is converted to the α-phase and the β-phase brass is removed to recover the corrosion resistance. is there.

[0005] α-brass is also used in the production of various metal products. Although α-brass is harder and has higher corrosion resistance than α + β brass, it has good forgeability at high temperatures of about 600 to 800 ° C. Not only that, it has the disadvantage of being expensive. In the manufacture thereof, it is general that a semi-finished product after casting is formed by cold forging at room temperature.

[0006]

In the case of forging a dezincification-resistant material, at room temperature, α is used in order to provide forgeability and corrosion resistance.
The component ratio is determined so that the phase and forging temperature (about 700 ° C.) become a mixed phase of α + β. However, since the β phase generated by heating during forging is brought to room temperature,
If left as it is, the β phase that deteriorates the corrosion resistance remains, and the corrosion resistance is insufficient. Therefore, in the conventional normal molding process,
Heat treatment (gelatinized annealing) had to be performed after hot forging.

However, in the case of α + β brass, even if an attempt is made to remove the β-phase brass increased in the step before hot forging by α-phase annealing, the post-heat treatment is performed within the component range for obtaining good forgeability. Is difficult to remove. For this reason, the final product will have poor corrosion resistance, and in order to compensate for this, it is necessary to increase the thickness of the product,
Since the heat treatment of the α-phase annealing requires a processing time of about 3 hours at a high temperature of about 550 ° C., the influence on the cost is great.

Next, the crystal structure and forgeability of brass, and the forging method and the characteristics of the molded product are shown in Tables 1 and 2, respectively.

[0009]

[Table 1]

[Table 2] From Table 1, the brass material originally had to choose the workability by the difference of the crystal structure based on the zinc content,
On the other hand, as shown in Table 2, since the characteristics of the obtained parts greatly differ depending on the processing method, it is necessary to realize processing having both of the advantages of the processing.

[0010] However, α brass is more excellent in corrosion resistance than α + β brass. However, when forging α brass, cracks are easily generated on the surface when forging at a high temperature (600 to 800 ° C). It is not suitable for manufacturing products having complicated shapes such as faucet fittings. For example, it is difficult to form a spout having a relatively simple shape as a faucet member.

As described above, in the case of α + β brass, although its workability is good, it is inferior in corrosion resistance. Therefore, it is limited that the thickness of the faucet must be increased.
On the other hand, α-brass has a problem in that the hot workability is greatly impaired and the product shape is restricted.

Accordingly, the present invention provides a brass material having a significantly improved hot workability, particularly a brass material which can be optimally used for faucet fittings, a method of manufacturing the same, and a brass product and the like. An object of the present invention is to provide a manufacturing method, a faucet fitting part, and a method for manufacturing the same.

[0013]

The brass material of the present invention is obtained by coating a surface of an α brass with a metal forming a β phase or an α + β phase, and subjecting the metal to heat diffusion treatment to form a β phase or an α + β phase on the α brass surface. Forming a layer. The metal to be coated is preferably zinc, and the coating is performed by a plating method or a method of performing heat diffusion treatment through a bonding medium.
Therefore, any coating method may be used as long as it is applied to a thickness capable of thermally diffusing through a bonding medium and then thermally diffused.

The heat diffusion treatment is preferably performed at a temperature of 600 ° C. to the melting point for one minute or more. Furthermore, after hot-forging a brass material having a layer in which a β phase or an α + β phase is formed on the surface of an α brass, the layer in which the β phase is formed on the surface is removed to obtain a brass product excellent in corrosion resistance. It can be manufactured.

A faucet fitting part is suitable as a brass product. The faucet fitting part is formed by hot forging a brass material having a layer in which a β phase or an α + β phase is formed on an α brass surface, and then forming a β phase on the surface. Is manufactured by removing the layer on which is formed by polishing and / or cutting.

After hot forging, plating may be performed after removing the layer on the surface where the β phase is formed.

Also, after hot forging a brass material having a layer in which a β phase or an α + β phase is formed on the surface of α brass, cold working can be performed to manufacture a faucet fitting part. As the processing, coining processing and / or thread rolling can be used.

[0018]

Table 3 shows the composition of the brass material of the present invention and the composition of the comparative example.
0 and C2600 are α brass, and the dezincification resistant brass rod is α brass by heat treatment. C3771 as a comparative example is α + β brass.

[0019]

[Table 3] FIG. 1 shows a Cu—Zn binary system equilibrium diagram. In the present invention, α brass is brass composed of α phase (for example, C220
0 and C2600), or brass (for example, a dezincification-resistant brass rod) in which α + β brass becomes α brass by heat treatment.

C3771 which is α + β brass of the comparative example is
In order to reduce the deformation resistance, it is heated and held at a temperature of about 700 ° C. in a step before hot forging, and β-brass is increased by this heating. Then, if improvement of corrosion resistance is necessary after hot forging, in order to reduce brass in the β phase, heat treatment is performed at a temperature of about 550 ° C. for about 3 hours and α phase annealing is performed to obtain a final product. .

In order to improve the hot workability, an electroplating method or a hot-dip galvanizing method can be applied to the zinc plating for forming a β phase or α + β phase layer on the surface of α brass.

For the metal coating, a barrel plating method can be used as one of the chemical methods in place of the zinc electroplating method or the hot-dip galvanizing method, and a mechanical method can be used. A plating method or a powder injection method can also be employed. Further, instead of the plating method, a bonding method using a bonding medium by bonding with an adhesive or ion coating may be used.

Then, the zinc-plated one is, for example, 6
By heating at a temperature of 00 to 800 ° C. for 5 to 15 minutes, a heat diffusion treatment of the plated zinc is performed. A layer of β phase or α + β phase is formed on the surface by the interfacial reaction due to the heat diffusion treatment of zinc. As a result, forging workability can be improved, and even if the product shape is complicated, it can be formed, and hot forging, which has been difficult with α-brass, can be performed. Naturally, the α-phase annealing becomes unnecessary.

Then, as a final step, a product can be obtained by subjecting a necessary portion to a cutting process or the like by machining, and a final product can be obtained after required steps such as plating. Here, when the faucet fitting is targeted for the product,
Since the β-phase layer which is formed on the surface in the machining process and causes corrosion is removed, the occurrence of the corrosion can be suppressed.

[0025]

FIG. 2 is a schematic view showing a process of manufacturing a brass material according to the present invention.

The brass material was a columnar shape having a diameter of 20 mm and a height of 20 mm.
0, C2600 and dezincification-resistant brass rod, C3 according to comparative example
771 were manufactured in the same shape.

C2200, C26 according to the embodiment of the present invention
Zinc plating is applied to the surface of each brass material 1 of the 00 and dezincification-resistant brass rods. A known electroplating method can be used for the electroplating method of zinc, and is not particularly limited. In the present embodiment, for example, zinc sulfate: 360 g / liter, ammonium chloride: 30 g / liter, acetic acid Sodium: Using a 500 cc sulfuric acid bath having a composition of 15 g / liter and a pH of 3 to 4.5, immersed the degreased brass material in the sulfuric acid bath for about 1 minute, and supplied a current of 0.5 at room temperature.
The galvanized layer 2 can be satisfactorily formed by energizing at 1 to 0.2 amps for 30 to 60 seconds.

Next, carbon is adhered to the upper and lower surfaces of the brass material 1 as a lubricant 3 at the time of forging in a later step, and the brass material 1 is placed in a heating furnace at 600 to 800 ° C.
Heat at a temperature of 5 to 15 minutes. By this heating, the zinc plating layer 2 formed on the surface causes an interfacial reaction to diffuse zinc, thereby generating a layer having a β phase formed on the surface.

FIG. 3 is an enlarged view of the structure of the longitudinal section near the surface of the brass material of the present invention. By performing a heat treatment after galvanizing, zinc is diffused and a coarse β A β-phase layer is formed, and its thickness is 150 to
It was about 250 microns.

The brass material having the β-phase layer formed on its surface is compressed in the axial direction by a press machine 4,
After compression molding at a processing rate of 70 to 80%, a final molded product 5 is obtained.

Comparison of the hot workability between the C2200, C2600 and the non-plated brass rods of the present invention plated with the zinc-free zinc-free rods shows that the non-plated ones have a working rate of about 50% on the surface. Although cracking occurred, the test piece of the present invention did not crack on the surface even when processed by 80%, and hot forging was favorably performed by forming a β phase layer on the surface. confirmed.

That is, unplated α-brass has poor forgeability at high temperatures, and cracks cannot be avoided on the surface during forging, whereas α-brass having a β-phase layer is formed.
Brass does not cause surface cracks due to its high ductility, and can be sufficiently applied to forming by hot forging.

Table 4 compares the maximum corrosion depths of the brass materials with numerical values obtained by actual measurement. In this test, a post-treatment of cutting the surface to remove the β-brass layer on the surface after forging is performed.

[0034]

[Table 4] As is clear from Table 4, C of the comparative example α + β brass
Since 3771 has poor corrosion resistance, the corrosion depth is much larger than that of the α-brass of the present invention.

Example 1 The manufacture of a faucet fitting body having openings in three directions as a valve body will be described. FIG. 4 is a manufacturing process diagram of the faucet fitting main body of the present invention. After the brass material 1 having the β phase or α + β phase formed on the surface of α brass is heated to the hot forging temperature, the brass material 1 is heated.
Is set in a mold, and is formed by hot forging with a punch to obtain a molded product 5 of a faucet fitting main body having a hollow portion.

The outer surface and inner surface of the molded product 5 of the faucet fitting body are subjected to polishing and / or thread cutting to remove burrs and the like, remove the β phase or α + β phase, form a screw, and finish the processing. .

The finished faucet fitting body 6 is finished by nickel chrome plating after cleaning the surface.

In this embodiment, Cu: 70%, S
Using a dezincification-resistant material having a composition of n: 1% and Zn: 29% (α single phase), and performing a zinc-rich surface treatment on the surface of the material, thereby eliminating heat treatment while ensuring forgeability. It became possible to do. The elimination of this heat treatment step resulted in significant energy saving effects such as a reduction in heating energy.

Embodiment 2 In the embodiment shown in FIG. 2, Cu: 70%, Sn: 1
%, Zn: 29% (α-single phase) using a dezincification-resistant material and subjecting the surface to a zinc-rich surface treatment, the parts obtained by forging are subjected to thread rolling and coining. Cold working becomes possible.

FIG. 5 is a view showing a manufacturing process of the faucet fitting body according to the present invention. It is set in a mold, and a faucet fitting part 7 having a hollow portion is formed by hot forging with a punch.

Next, the formed faucet fitting part is formed into a hexagonal nut part 8 by cold coining and a curved surface part 9 is finished. The cylindrical portion 10 is formed by rolling a screw 11
To form

Although the hexagon nut 8 is difficult to grind, finishing by cold coining improves the surface roughness, thereby improving the fitting accuracy of the inner surface, and makes finishing such as grinding and cutting unnecessary. Furthermore, since the cylindrical portion 10 is a long screw, the advantages of thread rolling can be utilized. Therefore, it has become possible to greatly improve the productivity of the same portion that has been conventionally processed by cutting.

[0043]

【The invention's effect】

(1) In the present invention, since a β-phase layer is formed on the surface of α-brass, the surface is processed regardless of the processing rate at which cracking has occurred in the conventional α-brass forging or a processing rate higher than that. Forging can be performed without causing cracks in the brass, and a brass product having an inexpensive and complicated shape can be obtained.

(2) Since the brass product produced by removing the β phase layer on the surface after hot forging is α brass, a brass product excellent in corrosion resistance can be obtained. By applying the method to manufacturing, it is possible to provide a low-cost and highly corrosion-resistant product.

(3) A complicated shape can be formed by hot forging, and a faucet which requires corrosion resistance can be formed because the β phase having low corrosion resistance is removed.

(4) In the case of a faucet, it is necessary to polish the surface because the surface is required to be clean. However, the polishing can remove the β phase having low corrosion resistance.

(5) The faucet body having a hollow portion is formed by hot forging, and the inner surface of the hollow portion is cut to remove a β phase having a low edible property.

(6) Since plating is performed after the β phase is removed, bonding with plating is also good, and the corrosion resistance is increased in combination with the corrosion resistance due to plating. Water of various temperatures such as cold water, hot water and hot water flows through the faucet fittings, so the change due to thermal expansion is remarkable, but the plating is well bonded, so it is difficult to peel off.

(7) Because of excellent hot forgeability and good cold workability, complex faucet parts can be formed by hot forging, and surface roughness can be improved by cold working, so polishing There is no need for finishing by machining such as cutting. However, in this case, since the β phase having low corrosion resistance remains thin on the surface, it is not suitable for parts requiring corrosion resistance.

[Brief description of the drawings]

FIG. 1 is a Cu—Zn binary system equilibrium diagram.

FIG. 2 is a schematic view showing a process of manufacturing a brass material of the present invention.

FIG. 3 is an enlarged view of a structure of a longitudinal section near the surface of the brass material of the present invention.

FIG. 4 is a manufacturing process diagram of the faucet fitting main body of the present invention.

FIG. 5 is a manufacturing process diagram of the faucet fitting part of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brass material 2 Zn plating layer 3 Lubricant 4 Press machine 5 Molded product 6 Faucet fitting main body 7 Faucet fitting part 8 Hex nut part 9 Curved surface part 10 Cylindrical part 11 Screw

Claims (14)

[Claims] 1. A brass material having a layer in which a β phase or an α + β phase is formed on an α brass surface and having excellent hot workability. 2. A hot workability in which a metal forming a β phase or an α + β phase is coated on an α brass surface and subjected to a heat diffusion treatment to form a layer having a β phase or an α + β phase formed on the α brass surface. Excellent brass material manufacturing method. 3. The method for producing a brass material having excellent hot workability according to claim 2, wherein the metal to be coated is zinc. 4. The coating according to claim 2, wherein the coating is a plating method.
Or the method for producing a brass material excellent in hot workability according to 3. 5. The method for producing a brass material excellent in hot workability according to claim 2, wherein the coating is subjected to heat diffusion treatment through a bonding medium. 6. The method according to claim 2, wherein the heat diffusion treatment is performed at a temperature of 600 ° C. to a melting point for 1 minute or more. 7. After hot forging a brass material having a layer in which a β phase or an α + β phase is formed on the surface of α brass, the β
A method for producing a brass product in which a layer in which a phase is formed is removed. 8. A hot-forging brass material having a layer in which a β phase or an α + β phase is formed on the surface of α brass,
A method for manufacturing a faucet fitting part for removing a layer in which a phase is formed. 9. A hot-forging brass material having a layer in which a β phase or an α + β phase is formed on an α-brass surface, and thereafter the surface
The method for manufacturing a faucet fitting part according to claim 8, wherein the layer in which the phase is formed is removed by polishing and / or cutting. 10. A brass material having a layer in which a β phase or an α + β phase is formed on an α brass surface is hot forged, and thereafter, plating is performed after removing the layer in which the β phase is formed on the surface. Or a method of manufacturing the faucet fitting part according to 9. 11. A faucet fitting component for hot forging a brass material having a layer in which a β phase or an α + β phase is formed on the surface of an α brass, and then removing the layer in which the β phase is formed on the surface. 12. A method of manufacturing a faucet component, comprising: forging a brass material having a layer in which a β phase or an α + β phase is formed on an α brass surface, followed by cold working. 13. The method of manufacturing a faucet fitting part according to claim 12, wherein the cold working is coining and / or thread rolling. 14. A faucet component formed by hot forging a brass material having a layer in which a β phase or an α + β phase is formed on an α brass surface, and then performing cold working.