JP2002013655A - Component member of brass-made passage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brass-made angle valve by forging work which is superior in anticorrosion and moreover cutting property is superior in productivity. SOLUTION: This component member of a brass-made passage is manufactured via a first process preparing a brass material of 37 to 46 wt.% an apparent Zn content and 0.5 to 7.0 wt.% an Sn content, a second process formed with a hollow part by warm or hot forging this brass material, a third process for adjusting a cutting character and anticorrosion after cooling by controlling a cooling speed after the warm or hot forging, and a fourth process for making cutting work penetrate the hollow part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brass flow path component provided in a pipe.

[0002]

2. Description of the Related Art Conventionally, when a brass forged product is used for a flow path constituting member such as a stop valve, corrosion resistance (dezincification corrosion resistance) is required.
For forging brass material with poor corrosion resistance, it is necessary to increase the wall thickness in consideration of the corrosion, or embed a stainless steel or bronze sheet material with excellent corrosion resistance in the valve seat part. As a result, productivity was low and manufacturing cost was high.

[0003] Alternatively, forging brass material having excellent corrosion resistance was sometimes used. However, after forging with a crystal structure of α + β mixed phase, it was converted into a substantially α single phase by long-time annealing. , And the production cost has been increased due to poor productivity due to long-time annealing.

[0004] It is also conceivable to use a brass material for casting instead of a brass material for forging. However, although the conventional brass material for casting can ensure dezincification corrosion resistance, it does not have SCC resistance or erosion corrosion resistance. In addition, there is a surface that cannot be satisfied, and deburring, cutting, surface polishing, and the like are required, and burrow leakage inspection is required.

[0005]

However, any of the conventional cases have some disadvantages, and the productivity has been impaired in order to solve these disadvantages.

SUMMARY OF THE INVENTION An object of the present invention is to provide a brass flow path component having excellent corrosion resistance and machinability and excellent productivity.

[0007]

Means for Solving the Problems and Actions / Effects of the Invention The present invention relates to a method for producing an alloy having an apparent Zn content of 37 to 46 wt%.
Then, a first step of preparing a brass material having a Sn content of 0.5 to 7.0 wt%, and a second step of forming a hollow portion by warm or hot forging the brass material By controlling the cooling rate after warm or hot forging, the cutability after cooling, the third step of adjusting the corrosion resistance, and the fourth step of penetrating the hollow portion by cutting, By manufacturing the brass flow path constituent member through the process, the productivity can be improved while securing the machinability and corrosion resistance after forging.

In the second step, a hollow portion is formed by forging. Such a hollow portion is usually formed by inserting a punch or the like, and is required to have a small deformation resistance. Further, when a hollow portion is formed in a portion extended by forging, a tensile stress is applied to the extended portion, so that high ductility with respect to the tensile stress is required.

In the present invention, during the warm or hot forging, the α + β phase having an area occupation ratio of the β phase of 30 to 80% and a crystal structure having an average crystal grain size of 15 μm or less, preferably 10 μm or less, The above requirements can be satisfied, and even when a hollow portion is formed in a hollow portion, particularly a portion extended by forging, cracking of a product can be eliminated. (For details, please refer to the applicant's PCT / JP97 / 0
Filed earlier at 3152)

[0010] The properties after cooling are as follows: When subjected to a dezincification corrosion test in accordance with the Japan Copper and Brass Association Technical Standard JBMA T-303, corrosion resistance with a maximum dezincification depth of 70 µm or less, and in accordance with Japanese Industrial Standard JIS C-3604. A cutting resistance index of 80 or more based on a free-cutting brass bar can be satisfied.

As an embodiment for ensuring the machinability, it can be performed by adjusting the area occupation ratio of the β phase.
As an embodiment for ensuring corrosion resistance, it can be performed by adjusting the Sn concentration in the β phase.

Specifically, the crystal structure after cooling is α + β
Phase and β phase have an area ratio of 15% or more, preferably 20% or more, and the average crystal grain size of α and β phases is 15 μm.
Or less, preferably 10 μm or less, and contained Sn in the β phase.
The concentration may be 1.5 wt% or more.

This crystal structure is 480 ° C. in the second step.
Heating as described above can be realized in the third step by setting the cooling rate to 400 ° C. or lower at 5 to 1000 K / sec.

In another embodiment for ensuring corrosion resistance, the β phase can be adjusted so as to surround the γ phase, and the Sn concentration in the γ phase can be adjusted.

Specifically, the crystal structure after cooling is α + β +
The area ratio of the γ phase and the α phase is 40 to 94%, the area ratio of the β and γ phases is 3 to 30%, and the average crystal grain size of the α and β phases is 15 μm or less, preferably 10 μm or less.
The average crystal grain size (minor diameter) of the phase is 8 μm or less, preferably 5 μm or less.
μm or less, and the Sn concentration in the γ phase is 8 wt.
% Or more as long as the γ phase surrounds the β phase.

The crystal structure is 480 ° C. in the second step.
By heating as described above, the third step can be realized by setting the cooling rate to 400 ° C. or lower at 0.4 to 10 K / sec.

In another embodiment for ensuring the machinability and the corrosion resistance, an α + γ phase is adjusted, the corrosion resistance is ensured by adjusting the Sn concentration in the γ phase, and the grain boundary area of the α phase and the γ phase is adjusted. Adjustability can ensure machinability.

Specifically, the crystal structure after cooling is α + γ
Phase and γ phase area ratio is 3 to 30%, preferably 5 to 30%.
%, The average crystal grain size of the α phase is 15 μm or less, preferably 10 μm or less, and the average crystal grain size (minor axis) of the γ phase is 8 μm or less, preferably 5 μm or less. It is sufficient that the Sn concentration is 8 wt% or more and the γ phase is scattered at the grain boundary of the α phase.

This crystal structure is 480 ° C. in the second step.
Heating is performed as described above, and the third step can be realized by setting the cooling rate to 400 ° C. or lower to 0.4 to 5 K / sec.

As an embodiment of the cutting in the fourth step, a plurality of hollow parts formed in the second step may be penetrated, and the hollow part formed in the second step and the hollow part formed in the second step may be penetrated. In step 4, the space between the hollow portion formed by the cutting process and the hollow portion may be penetrated.

As an embodiment of the hollow portion after the penetration,
A flow passage inlet hole, a flow passage outlet hole, and an on-off valve insertion hole can be configured. Specifically, the flow passage entrance hole and the on-off valve insertion hole have substantially the same axis, The exit holes may be substantially orthogonal in axis.

In the present invention, in particular, a valve seat hole in which the on-off valve valve element inserted into the on-off valve insertion hole is seated can be formed on the inner wall of the on-off valve insertion hole. That is, since the crystal structures after cooling in the present invention are all excellent in erosion corrosion resistance, it is not necessary to use another member such as a seat member embedded in a valve seat hole as in the related art.

[0023]

Embodiments of the present invention will be described in detail below. FIG. 1 is a sectional view showing a water stopcock as an example of an angle type valve, FIG. 2 (a) is a manufacturing process diagram of a brass angle type valve by conventional forging, and FIG. Manufacturing process diagram of the brass angle type valve, FIG. 3 is a schematic diagram of forging, FIG. 4A is an external view of the main body after forging,
4B is a cross-sectional view thereof, FIG. 5A is an external view of the main body after cutting, and FIG. 5B is a cross-sectional view thereof.

In FIG. 1, the water stopcock (A) has a body (1) whose axis (x) in the direction of the inlet (2) and axis (y) in the direction of the outlet (3) are substantially orthogonal to each other. ) Direction is formed in a substantially T-shape combining three cylindrical portions (5), (6) and (7) in which the axis (x) of the direction and the axis (z) of the operation direction of the on-off valve (4) substantially coincide with each other. A partition wall (9) having a valve seat hole (8) is provided at a position offset from the axis in the direction (3) toward the inlet (2).

A hexagonal portion (10) for holding a tool such as a spanner is formed on the outer periphery of the cylindrical portion (5) on the inlet side, and a female screw (12) for connecting a water supply pipe (11) is formed on the inner periphery. The formed inlet hole (13) is formed.

An outlet hole (15) for inserting a copper tube (14) connected to a ball tap (not shown) or the like is provided on the inner periphery of the cylindrical portion (6) on the outlet side. 1
Male screw (1) for cap nut (16) for fixing 4)
7) is engraved.

A spindle (1) having a seal packing (18) attached to the tip thereof on the inner periphery of the opening / closing valve side cylindrical portion (7).
An opening / closing valve hole (21) provided with a female screw (20) screwed into 9) is provided, and a male screw (23) to which a cap nut (22) is attached is formed on the outer periphery thereof.

Reference numeral (24) denotes a handle for the open / close valve (4), and (25) denotes a cap nut packing.

In FIG. 2A, conventionally, the brass material prepared in the first step (I) is heated in the second step (R), and then forged with the α + β mixed phase in the third step (H). After cooling to room temperature in the fourth step (ス テ ッ プ), deburring in the fifth step (ほ), pickling in the sixth step (へ), shot blasting in the seventh step (と), and the eighth step (（) In step (1), annealing is performed to change the crystal structure into an α single phase. Thereafter, machining such as cutting in the ninth step (R) is performed to complete the manufacture of the angle type valve body (1).

The problem here is the annealing in the eighth step (c). That is, the eighth step (C)
This is because the α single-phase brass obtained as a result has excellent corrosion resistance but poor machinability.

In order to solve this, there is a method of changing the order of the eighth step (C) and the ninth step (G). However, an oxide film may be formed at the time of annealing. However, there is a problem that the dense shape and the finish quality of the above are impaired when the oxide film is removed.

Next, the embodiment of the present invention shown in FIG. 2B will be described. First, in the first step (a), the apparent Zn content is 37 to 46 wt%, and the Sn content is apparent. A brass material having an amount of 0.5 to 7.0 wt% is prepared, and this brass material has a crystal structure with an average crystal grain size of <15 μm in the previous step.

Here, the term "apparent Zn content" means that A is Cu content [wt%], B is Zn content [wt%], and t is a third element (for example, Sn). Z
When n equivalents and Q are the content of the third element [wt%], “{(B + t · Q) / (A + B + t · Q)} × 10
0 ”is used. Further, a small amount of Pb may be contained for improving the machinability.

Next, in the heating and forging process, which is the second process, in the second step (b), the prepared brass material
In the third step (c), warm or hot forging is performed on the α + β mixed phase having an area ratio of the β phase of 30 to 80% in the third step (c). At step (c), attention must be paid to the coarsening of the crystal grain size. This is because not only does it affect the machinability and corrosion resistance in the subsequent steps, but also the forgeability is significantly reduced when the average crystal grain size exceeds 15 μm.

When the forging is completed, the third step, the fourth step
The process moves to the cooling of step (d). In the embodiment (b), the role played by the eighth step (c) of the conventional example (a) is replaced by the fourth.
Step (d) has it. That is, although a crystal structure having excellent corrosion resistance is realized, the difference from the conventional example (a) is that it is not due to the α single phase as shown in Examples 1 to 3 below.

Example 1 A cooling rate of 5 to 1000 K /
After cooling, after cooling, the area occupancy ratio of the β phase in the α + β phase is 20% or more, the average crystal grain size of the α and β phases is 10 μm or less, and the Sn concentration in the β phase is 1.5 wt% or more. Was obtained. The corrosion resistance of the β phase is ensured by securing the Sn concentration in the β phase, and the cutting property is secured by securing the area occupation ratio of the β phase.

[Example 2] The cooling rate was set to 0.4 to 5 K / s.
ec, after cooling, in the α + γ phase, the area occupation ratio of the γ phase is 5 to 30%, and the average crystal grain size of the α phase is 10 μm.
m, the average crystal grain size (minor axis) of the γ phase is 5 μm or less, γ
A crystal structure was obtained in which the Sn concentration in the phase was 8 wt% or more and the γ phase was scattered at the grain boundaries of the α phase. The corrosion resistance of the γ phase is ensured by ensuring the Sn concentration in the γ phase, and the machinability is ensured by the hardness difference at the grain interface between the hard γ phase and the soft α phase.

Example 3 The cooling rate was set to 0.4 to 10 K /
sec, after cooling, α + β + γ phase, α
The area occupancy of the phase is 40 to 94%, the area occupancy of the β and γ phases is 3 to 30%, and the average crystal grain size of the β phase is 10 μm.
m, the average crystal grain size (minor axis) of the γ phase is 5 μm or less, γ
A crystal structure in which the Sn concentration in the phase was 8 wt% or more and the γ phase surrounded the β phase was obtained. Ensuring the corrosion resistance of the γ phase by securing the Sn concentration in the γ phase, preventing the dezincification corrosion of the β phase by surrounding the β phase with the γ phase, the presence of the β phase, and the hard γ phase and soft α The machinability is secured by the difference in hardness at the grain interface with the β phase.

As described above, Examples 1 to 3 all show good characteristics in both corrosion resistance and machinability. Specifically, first, as good corrosion resistance, the Japan Copper and Brass Association technical standard JBMA
When a dezincification corrosion test based on T-303 was performed,
Satisfies the corrosion resistance with a maximum dezincing depth of 70 μm or less.

Further, as a good cutting property, a cutting resistance index of 8
Satisfies 0 or more. This will be described in detail with reference to FIG. 6. In the cutting test, the peripheral surface of the round bar-shaped sample A was
The main component force Fv was measured while cutting at two different speeds of 0 [m / min] and 400 [m / min]. The cutting resistance index of the working example is a free-cutting brass rod (Japanese Industrial Standard JIS C-
3604). (The cutting resistance index for each cutting speed was averaged.)

According to the crystal structures of Examples 1 to 3,
It also shows good characteristics in SCC resistance. Specifically, when a cylindrical sample is exposed to an ammonia atmosphere on a 14% aqueous ammonia solution for 24 hours while applying a load, the maximum stress at which the sample does not crack satisfies the characteristic of 180 N / mm 2 or more. The SCC test was performed as shown in FIG.
The sample was exposed to an NH3 vapor atmosphere for 24 hours in a state where a load was applied vertically to the cylindrical sample C in the glass digitator B, and then the occurrence of cracks was examined.

Further, according to the crystal structures of Examples 1 to 3, good characteristics are also exhibited in erosion corrosion resistance. FIG.
In the erosion corrosion resistance test shown in (1), a cylindrical sample E having an orifice D therein was used, and after flowing water through the orifice D at a flow rate of 40 m / sec for a predetermined time, 4.9 ×
Orifice D under water pressure of 105 Pa (5 kg / cm2)
Of the resin stopper F required for sealing was measured.

The results of the test in FIG. 8 are as shown in FIG. 9, and the brass materials of Examples 1 to 3 obtained better characteristics than the conventional example. In the conventional example, a Sn content of 0.5 wt% was used.

Returning to FIG. 2, in the embodiment (b), following the fourth step (d), deburring in the fifth step (e), pickling in the sixth step (f), and the seventh step Although the shot blasting of (g) is performed, the process proceeds to the machining such as cutting in the eighth step (h) which is the fourth step without passing through the annealing of the eighth step (c) of the conventional example (a). .

That is, during the cooling in the fourth step (d), a crystal structure having excellent corrosion resistance was already obtained, so that the annealing in the eighth step (c) of the conventional example (a) became unnecessary. Also in the cutting in the eighth step (h) of the embodiment, the machinability is improved as compared with the case of cutting the α single phase in the conventional example (a).

Next, the forging process of the angle type valve body will be described with reference to FIG.

The angle type valve body (1) is formed by disposing a rod-shaped material (not shown) in a mold (26), and has an outer shape obtained by combining three cylindrical portions (5), (6) and (7). It is formed almost in a T-shape, and three punches (27), (28), (29) are inserted from the inlet (2) direction side, the operation direction side of the on-off valve (4) and the outlet (3) direction side, and the outlet is inserted. The first partition wall (9) is located at a position offset from the axis (y) of the (3) axis toward the inlet (2), and the axis (z) of the operating direction of the on-off valve (4).
The second partition (3) is located at a position offset from the center toward the outlet (3).
0) to provide an inlet hole (13) and an open / close valve hole (2).
1) and plastically deform so as to open the exit hole (15).

The flesh portion of the cylindrical portion (6) does not exist at the position shown in the figure at the stage of the rod shape, and when the die (26) is forged or the punches (27) and (28) are inserted, The material is formed at the position shown in the figure by elongating the material.

After obtaining the crystal structures of Examples 1 to 3 by controlling the cooling rate in the fourth step (d), deburring in the fifth step (e) and pickling in the sixth step (f) 4 through the shot blast in the seventh step (g), and the shape shown in FIG. 5 is obtained by performing the cutting in the eighth step (h).

That is, a female screw (12) is engraved on the inner periphery of the entrance hole (13) on the entrance side cylindrical portion (5), and a male screw (17) is formed on the outer periphery of the exit side cylindrical portion (6). At the same time, the water hole (3) is formed in the second partition (30) from the outlet hole (15) side.
1) is established and communicated with the opening / closing valve hole (21).

A female screw (20) is engraved on the inner periphery of the opening / closing valve hole (21) of the opening / closing valve side cylindrical portion (7), and a male screw (23) is engraved on the outer periphery.

The first partition (9) has an inlet hole (13).
The valve seat (8) is opened from the side or the opening and closing valve hole (21) side, and the valve seat (32) is processed from the opening and closing valve hole (21) side.

As described above, since the main body (1) is subjected to cutting after forging, and is used for a portion where corrosion resistance is required, the cutting performance and corrosion resistance are excellent as in Examples 1 to 3. It is preferable to use a forged product.

It is preferable to form the valve seat portion (32) directly on the first partition (9). This is because the valve seat portion (32) has a high flow velocity and receives a tightening force. Therefore, a material having excellent erosion corrosion resistance as in the present embodiment is preferable.

In the present embodiment, punches are inserted from three directions during forging. However, two punches are inserted from two directions on the inlet side and the operation direction of the on-off valve during forging, and the punch is inserted into the inlet hole. An opening and closing valve hole may be opened, and an outlet hole may be opened by cutting after forging.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a water stopcock as an example of an angle type valve.

FIG. 2 (a) is a manufacturing process diagram of a conventional brass angle type valve by forging, and FIG. 2 (b) is a manufacturing process diagram of a brass angle type valve of the present embodiment.

FIG. 3 is a schematic diagram of a forging process.

4A is an external view of a main body after forging, and FIG. 4B is a cross-sectional view thereof.

5A is an external view of a main body after cutting, and FIG. 5B is a cross-sectional view thereof.

FIG. 6 is an explanatory diagram of a cutting test.

FIG. 7 is an explanatory diagram of an SCC resistance test of the same embodiment.

FIG. 8 is an explanatory diagram of an erosion corrosion resistance test of the same embodiment.

FIG. 9 shows an erosion corrosion resistance test result of the same embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body, 2 ... Inlet, 3 ... Outlet, 4 ... Opening / closing valve, 5 ...
Inlet side cylindrical part, 6 ... Outlet side cylindrical part, 7 ... Opening / closing valve side cylindrical part, 8 ... Valve seat hole, 9 ... First partition part, 13 ... Inlet hole part, 15 ... Outlet hole part, 21 ... Open / close valve hole, 26 ...
Mold, 27, 28, 29 ... punch, 30 ... second partition part,
31: communication hole, x: axis in the entrance direction, y: axis in the exit direction,
z: axis of operation direction, a: first step, b, c: second step, d: third step, h: fourth step, A: machinability test B: glass digitator, C: sample for stress corrosion cracking resistance test, D: orifice, E: sample for erosion corrosion resistance test, F: resin stopper

Continuation of the front page F term (reference) 3H051 AA01 AA04 BB01 BB06 CC11 DD03 EE02 FF14

Claims (19)

[Claims] 1. An apparent Zn content of 37 to 46 wt.
%, A first step of preparing a brass material having a Sn content of 0.5 to 7.0 wt%, and a second step of forming a hollow portion by warm or hot forging the brass material. Process and by controlling the cooling rate after warm or hot forging,
A third step of adjusting the cutability after cooling and the corrosion resistance, and a fourth step of penetrating the hollow portion by cutting.
A brass flow path component produced through the following. 2. The brass flow path component according to claim 1, wherein at least one of the hollow portions is formed in a portion extended by the warm or hot forging in the second step. 3. In the second step, during the warm or hot forging, α + β having an area occupancy ratio of the β phase of 30 to 80% is used.
Phase, average crystal grain size is 15 μm or less, preferably 10 μm
The brass flow path component according to claim 1 or 2, having the following crystal structure. 4. The characteristics after cooling include corrosion resistance at a maximum dezincification depth of 70 μm or less when subjected to a dezincification corrosion test in accordance with the Japan Copper and Brass Association Technical Standard JBMA T-303, and Japanese Industrial Standard JIS C-3604. The brass flow path component according to any one of claims 1 to 3, which satisfies a machinability having a cutting resistance index of 80 or more based on a free-cutting brass bar according to claim 1. 5. The brass flow path component according to claim 4, wherein in the third step, the cutting property is ensured by adjusting the area occupancy ratio of the β phase. 6. The method according to claim 3, wherein in the third step, Sn in the β phase
6. The brass flow path component according to claim 5, wherein the corrosion resistance is ensured by adjusting the concentration. 7. The crystal structure after cooling has an area ratio of α + β phase and β phase of 15% or more, preferably 20% or more, and an average crystal grain size of α and β phases of 15 μm or less, preferably 10 μm. The brass flow path component according to claim 6, wherein the Sn concentration in the β phase is 1.5 wt% or more. 8. The brass flow according to claim 7, wherein the heating is performed at 480 ° C. or more in the second step, and the cooling rate until the temperature is reduced to 400 ° C. or less is 5 to 1000 K / sec in the third step. Road components. 9. The brass flow path according to claim 5, wherein in the third step, the β phase is adjusted so as to surround the γ phase, and corrosion resistance is secured by adjusting the Sn concentration in the γ phase. Components. 10. The crystal structure after cooling is α + β + γ
Phase and α phase have an area ratio of 40 to 94%, β and γ phases have an area ratio of 3 to 30%, and α and β phases have an average crystal grain size of 15 μm or less, preferably 10 μm or less, and γ phase. Has an average crystal grain size (minor diameter) of 8 μm or less, preferably 5 μm.
m or less, and the Sn concentration in the γ phase is 8 wt%.
The brass flow path component according to claim 9, wherein the γ phase surrounds the β phase. 11. The method according to claim 10, wherein the heating is performed at 480 ° C. or more in the second step, and the cooling rate until the temperature is reduced to 400 ° C. or less is 0.4 to 10 K / sec in the third step. Copper flow path component. 12. In the third step, an α + γ phase is adjusted, the corrosion resistance is ensured by adjusting the Sn concentration in the γ phase, and the machinability is ensured by adjusting the grain boundary area between the α phase and the γ phase. The brass flow path component according to claim 4, wherein: 13. The crystal structure after cooling has an α + γ phase, γ
The area ratio of the phase is 3 to 30%, preferably 5 to 30%, the average crystal grain size of the α phase is 15 μm or less, preferably 10 μm or less, and the average crystal grain size (minor axis) of the γ phase is 8
μm or less, preferably 5 μm or less, and further γ
13. The brass flow path component according to claim 12, wherein the Sn concentration in the phase is 8 wt% or more, and the γ phase is scattered at the grain boundary of the α phase. 14. The method according to claim 13, wherein the heating is performed at 480 ° C. or more in the second step, and the cooling rate until the temperature is reduced to 400 ° C. or less is 0.4 to 5 K / sec in the third step. Copper flow path component. 15. The method according to claim 1, wherein in the fourth step, a plurality of hollow portions formed in the second step are penetrated.
5. The channel member made of brass according to any one of 4. 16. The method according to claim 1, wherein the fourth step penetrates between the hollow part formed in the second step and the hollow part formed by cutting in the fourth step. 1
5. The channel member made of brass according to any one of 4. 17. The hollow part having passed therethrough is used for inserting a flow passage inlet hole, a flow passage outlet hole, and an open / close valve for opening and closing a flow passage from the flow passage inlet hole to the flow passage outlet hole. The brass flow path component according to any one of claims 1 to 16, further comprising an on-off valve insertion hole. 18. The brass flow according to claim 17, wherein the flow passage entrance hole and the opening / closing valve insertion hole have substantially the same axis, and the flow passage entrance hole and the flow passage exit hole have substantially perpendicular axes. Road components. 19. The brass flow path configuration according to claim 17, wherein a valve seat hole in which an on-off valve valve body inserted into the on-off valve insertion hole is seated is formed on an inner wall of the on-off valve insertion hole. Element.