JPS6086239A - Valve - Google Patents

Abstract

PURPOSE:To develop a valve capable of being used for a long period of time without using expensive Co, by constituting the valve seat of a valve consisting of a valve body having the valve seat or a valve case having the valve seat from an Ni-base alloy having a specific composition and integrating the same with the valve body or the valve case by diffusion bonding. CONSTITUTION:The valve seat of a valve used in various plants is made of a Ni-base alloy containing 10-45% of Cr, 1.5-6% of at least one of Al and Ti and less than 20% of Mo. Because the alloy having this composition contains Ti or Al and hardly welded, an Ni-Si-B alloy, an Ni-B alloy or an Ni-P alloy is used as a diffusion bonding material 10 to integrate the valve seat 1 with a valve body 3 or a valve case 4 by diffusion bonding. Or, in a valve comprising a valve body having the valve seat and a valve seat sheet 2 or a valve case having the valve seat 1 and the valve seat sheet 2, the valve seat 1 made of the alloy having the above mentioned composition is integrated with the valve seat sheet 2 by diffusion bonding. By this method, the long period use of the valve is enabled by using the valve seat with no expensive Co at all.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a valve, and more particularly to a valve that can be used for a long period of time.

[Technical background of the invention and its problems] Conventionally, pulp valve seats used in various plant fields such as chemical and atomic couplants have been made of cobalt-based alloys, commonly known as stellite, to provide wear and erosion resistance. It is fully welded.

However, when such overlay welding is performed, there are drawbacks such as entrainment of oxides, generation of pinholes, and occurrence of cracks during welding.

Furthermore, recently, Ni-based welding materials have been developed in view of the depletion of cobalt resources and improvements in the safety of atomic couplants, but their wear resistance and erosion resistance are not as good as those of stellite. 0 [Object of the Invention] An object of the present invention is to provide a valve having a valve seat that does not contain cobalt as an alloying element and can be used for a long period of time without causing the above-mentioned drawbacks.

[Summary of the Invention] The present invention provides a valve having a valve body having a valve seat and/or a valve body having a valve seat, in which the valve seat is made for company M and has at least one of C'10 to 45 Ti, M and Ti. Any 1 fm
1.5 to 6%, MO 20% or less, remaining Ni Karanari and the valve seat are diffusion bonded to the valve body and/or the valve body, respectively, and the valve body and/or the valve body having the valve seat and the valve seat seat. In a valve consisting of a valve body having a valve seat and a valve seat, the valve seat has a weight ratio of 10 to 45% of C, 15 to 6% of at least one of A and Ti, M
The valve seat is characterized in that the valve seat is diffusion bonded to a valve seat, and the valve seat is welded to a valve body and/or a valve body, respectively.

The present invention will be explained in detail below.

An example of a valve according to the present invention is shown in FIG. In the figure, 1 is a valve seat, 2 is a valve seat, 3 is a valve body, 4 is a valve box, 5 is a diffusion joint, 6 is a welded part, 7 is a valve stem, 8 is a bonnet, and 9 is a handle. Note that the valve shown in FIG.
Alternatively, although the valve seat 1 is welded to the valve body 4, the valve seat 1 may be directly diffusion bonded to the valve body 3 or the valve body 4 without interposing the valve seat sheet 2.

Valve seat 1 contains 10 to 45% Cr by weight, 1.5 to 6% of at least one of M and Ti, and MO20.
The reason for limiting these compositions is as follows. If the modulus exceeds 45, the coarse initial product phase crystallizes or precipitates excessively, making it impossible to obtain the required wear resistance.On the other hand, Ae, T
i or both are components that react with Ni and contribute to strengthening the base of the alloy and improving wear resistance, but if it is less than 1.5%, the effect is insufficient, and if it exceeds 6%, the toughness will decrease. This is because the mechanical strength of the material is impaired. Furthermore, Mo is intended to improve corrosion resistance and strengthen the alloy matrix to further improve wear resistance, but if the number exceeds 20 threads, the toughness of the resulting alloy decreases. Moreover, the valve seat machine according to the present invention is AA! + Part of Ti may be replaced with Nb or Ta, and part of Ni may be replaced with Fe.M
A part of o can also be replaced with W. Furthermore, Mn, Si, etc. may be included as a deoxidizing agent and a depilating agent added at the time of melting.

In addition, according to the present invention 1, since the valve seat machine is made of one layer of thin material (contains leaf AA' and is difficult to weld), the valve seat is made by casting and is joined to the valve body, valve box, or valve seat seat by diffusion bonding. On the other hand, the materials of the valve body 3 and valve body 4 are not particularly limited, and any conventionally used materials can be used. When diffusion bonding 1 to the valve body 3 or valve box 4 (valve P, W sheet 2, if the sheet 2 is interposed, these may be directly discussed, but the diffusion bonding material In this case, the bonding strength is 05. The diffusion bonding material is usually a nickel-based alloy or an iron-tin alloy, preferably a nickel-silicon-boron alloy or a nickel-boron alloy. A nickel-phosphorus alloy or a nickel-phosphorus alloy is used.

In addition, when the valve seat 1 is diffusion bonded to the valve body 3 or the valve body 4 (or the seat 2 if the valve seat sheet 2 is interposed), for example, as shown in FIG. It is possible to increase the joint strength by increasing the area, or to weld part or the entire periphery of the valve seat as shown in FIG. 3 to prevent gap corrosion and increase the joint strength.

Of the present invention, in order to manufacture a valve in which the valve seat is directly diffusion bonded to the valve body or valve body, first, these diffusion bonding surfaces are cleaned, and then a diffusion bonding material is placed on the valve body or valve body. Then, a valve seat material is placed on the material and diffusion bonding is performed. On the other hand, in order to manufacture a valve with a valve seat seat interposed, a diffusion bonding material is placed on a cleaned valve seat sheet, and the valve seat whose diffusion bonding surface has been cleaned is placed on the bonding material with 1 & i faces. After that, diffusion bonding is performed, and then the sheet is welded to the valve body or valve body.

Diffusion bonding may be performed in air, but is preferably performed in an inert gas or vacuum. In addition, when diffusion bonding is performed using a diffusion bonding material, the processing time is shortened and the temperature does not need to be so high. The same conditions as those known in the art may be followed.

N, Decristofaro and C+Hen5
chel: Weld, J., 57.33 (
(1978) et al.

[Effects of the Invention] Since the valve of the present invention has a valve seat bonded by diffusion bonding, there is no possibility of entrainment of oxides, generation of pinholes, or cracking during welding, as would be the case if the valve seat was formed by overlay welding. There is no risk of this occurring. In particular, the absence of pinholes and oxide entrainment makes it easy to grind the valve seat surface, which is advantageous not only during manufacturing but also during repair.

Furthermore, the valve seat material according to the present invention has wear resistance and erosion resistance (K) and does not contain cobalt, making it particularly suitable for valves for atomic couplants.

[Examples of the Invention] Examples 1 to 3 Various elements shown in Table 1 were blended in predetermined parts and melted using a high frequency melting furnace. From the obtained molten metal, a diameter of 155 mm,
A ring plate having a width of 25 mm and a thickness of 6 TnIx was cast, and then the ring plate was processed into a base plate having a diameter of 150 mm, a width of 20 um, and a thickness of 5 mm, and the surface was cleaned.

Next, as shown in FIG. 4, a valve body 3 made of 5US316 is prepared, and a B4 section, a CR15.2 section, and the remaining N
A diffusion bonding material 10 having a thickness of 35 μm was placed from I, and the ring plate obtained above was placed on top of the bonding material 10, followed by diffusion bonding to form the valve seat 1. In this diffusion bonding, 2
X IQ - First, pressure IK in a 5 torr atmosphere,
g/cIlt, B degree A bonding process was carried out at 1150°C for 0.5 hours, and then a diffusion process was carried out at a temperature of 1150°C for 5 hours. Finally, it was aged at 750°C for 10 hours. The valve seats obtained through the above treatment were visually observed, but no cracks were observed in any of the examples.

Next, a valve seat 1 and a valve box 4 were prepared in the same manner, and these were combined to form a valve.

A cavitation erosion test piece shown in Fig. 6a (11 in the figure is the diffusion bonding layer) was prepared from the valve obtained as described above, and an amplitude of 90 μm, frequency &
An erosion test was conducted at 6.5 KHz for 3 hours* to measure the amount of wear on the valve seat surface. The obtained results are also listed in Table 1.

Comparative Examples 1 to 2 The various elements listed in Table 1 were blended at predetermined positions, melted using a high-frequency melting furnace, and then the resulting molten metal was heated to a diameter of 5 TR11 and a length of 300 mm using the glass tube vacuum absorption method. Manufactured overlay welding rods. Next, in the same manner as in the above embodiment, the valve body 3 was overlaid using the overlay welding rod. In the overlay welding, 5 layers were overlaid at a current of 140 A and a voltage of 5 V, and approximately 8
A built-up part of myt was formed.

Next, the surface of the built-up portion was machined to a thickness of 5 mm to form a valve seat. When the obtained valve seat was visually observed, the occurrence of minute racks was observed.

Next, in the same manner, a valve seat 1 was welded to a valve body 4, and these were combined to form a valve.

Next, a cavity erosion test piece as shown in Fig. 6b (in the figure, 11 is the overlay welding layer) was prepared from the Tokuda valve as described above, and a cavity erosion test piece as shown in Fig. A cavitation erosion test was conducted using the following methods to measure the amount of wear on the valve seat surface.The obtained results are also listed in Table 1.

The following margin examples 4 to 6 are made in the same manner as in the previous example.C3US316! 1 on the valve seat sheet 2 of J (the diffusion bonding material 10 is placed, and then the bonding material J
A ring plate having the alloy composition shown in Table 2 was placed on the O, and then diffusion bonded to form the valve seat 1 shown in FIG. 5. The valve seat was diffusion bonded in the same manner as in Examples 1 to 3 above.

Next, the valve seat sheet 2 was welded to the valve body 3, and the valve seat sheet 2 obtained in the same manner was welded to the valve box 4, and these were combined to form a valve.

A cavitation erosion test piece shown in Figure 6a was prepared from the valve obtained as described above, and a cavitation erosion test was conducted in the same manner as in the previous example to measure the amount of wear on the valve seat surface. .

The obtained results are also listed in Table 2Q.

Comparative Examples 3 to 4 Predetermined amounts of various elements listed in Table 2 were blended and melted using a high-frequency melting furnace, and the resulting molten metal was vacuum-absorbed into a glass tube with a diameter of 5 rtutc% and a length of 300 mm. manufactured overlay welding rods. Next, overlay welding was performed on the valve seat sheet 2 made of 5US31 (manufactured by No. 5) using the overlay welding rod to form a valve seat.
Form the valve seat by overlay welding in the same manner as above. In addition, regarding Comparative Example 6, the final aging treatment was performed at 750° C. for 10 hours. When the obtained valve seat was visually observed, the occurrence of minute racks was observed.

Next, the valve seat sheet 2 was welded to the valve body 3, and the valve seat sheet 2 obtained in the same manner was welded to the valve box 4, and these were combined to form a valve.

Next, from the obtained valve, a cavitation erosion test piece shown in FIG.
The wear and tear area on the surface of the valve seat was measured.

The obtained results are also listed in Table 2.

As is clear from the β self test results below, the Z valve according to the present invention has less wear than the comparative example and does not contain cobalt, so it is suitable as a valve for various plants such as chemical and nuclear power plants. .

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a valve according to the present invention, and FIG.
The figure is a partial schematic diagram of a valve according to the present invention in which the area of the diffusion bonding surface is increased to increase the bonding strength, and FIG. FIG. 4 is a partial schematic diagram of a valve according to the present invention that does not use a valve seat, and FIG.
1≦A partial schematic diagram of a valve according to the present invention using a sheet, FIG. 6 (α) is a partial schematic diagram of a gear pitcher erosion test piece according to the present invention, and FIG. 6 (b) is a conventional overlay. FIG. 3 is a partial schematic diagram of a welded cavitation erosion test piece. l... Valve seat, 2... Valve seat, 3... Valve body, 4...
Valve box, 5... Diffusion joint, 6... Welded part, 7...
・Valve stem, 8...bonnet, 9.handle, 10...
Diffusion bonding material, 11... Diffusion bonding layer, 12... Overlay welding layer. 'Xl Figure 2 Figure 4 Figure 5? 6 Figure 6 (and') tbノ

Claims (2)

[Claims] (1) In a valve consisting of a valve body having a valve seat and/or a valve body having a valve seat, the valve seat has a weight ratio of at least one of the following: C"10 to 45, A/and Tt. ．．
5 to 6, Mo: 20 or less, and the remainder: NI, and the valve seat is diffusion bonded to a valve body and/or a valve box, respectively. (2) A valve consisting of a valve body having a valve seat and a valve seat and/or a valve body having a valve seat and a valve seat? The valve seat has a weight ratio of C10 to 45%, at least one of Aj? 1. A valve characterized in that the valve seat is diffusion bonded to a seat seat, and the seat seat is welded to a valve body and/or a valve body, respectively.