JPH1143733A - Diaphrgam made of ni base alloy of diaphragm valve having high strength and high hardness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the diaphragm of a diaphragm valve having high-strength and high hardness and excellent is spring properties and corrosion resistance as well by composing it of an Ni base alloy contg. Cr, Ta, Mo, Al, and the balance Ni with inevitable impurities. SOLUTION: The Ni base alloy composing the diaphragm has a compsn. contg., by weight, 17 to 25% Cr, 1.1 to 3.4% Ta, 17 to 22% Mo and 0.1 to 0.8% Al, furthermore contg., as necessary, 0.1 to 1% Fe, and the balance Ni with inevitable impurities. Cr forms aesthetic phases in the matrix with Cr to improve its corrosion resistance and forms intermetallic compds. with Mo and Ni to improve its strength and hardness. Mo enters into solid solution in the matrix to improve the corrosion resistance and forms the above intermetallic compds. to improve the strength and hardness. Ta enters into slid solution in the matrix to improve the corrosion resistance. Al shows oxidizing operation and enters into solid solution in the matrix to improve the strength. Fe enters into solid solution in the matrix to improve its hot workability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diaphragm made of a Ni-based alloy for a diaphragm valve having high strength and high hardness, and excellent in spring property and corrosion resistance.

[0002]

2. Description of the Related Art Conventionally, for example, in the manufacture of semiconductor devices, for example, gas cleaning is performed in various manufacturing steps. Many gas valves are provided in such a gas cleaning apparatus for controlling cleaning gas. Built into the piping. In particular, the diaphragm, which is a structural member of the diaphragm valve, is exposed to a cleaning gas such as HCl, HBr, or a highly corrosive halogen gas such as HF. For example, a Ni-based alloy having high corrosion resistance, such as a Ni-based alloy described in Japanese Patent Publication No. 2-8017, is used.

[0003]

On the other hand, recent semiconductor devices tend to be highly integrated, and accordingly, for example, fine adjustment is required for a cleaning atmosphere pressure of a gas cleaning device. It is indispensable to make the wall thinner that can respond to the adjustment, and it is inevitable to increase the size of the gas cleaning device due to the necessity of labor saving. Since the conventional corrosion resistant Ni-based alloy diaphragm does not have sufficient strength and hardness, it cannot be satisfactorily coped with the reduction in thickness and area of the diaphragm.

[0004]

Means for Solving the Problems Accordingly, the present inventors have
In view of the above, the diaphragm has excellent spring properties and corrosion resistance required for the diaphragm, and has been studied to develop a diaphragm having high strength and high hardness. % Indicates weight%), Cr: 17 to 25%, Mo: 17 to 22%, Ta: 1.1 to 3.4%, Al: 0.1 to 0.8%, further required Fe: 0.1 to 1%, depending on
And the remainder is composed of a Ni-based alloy having a composition consisting of Ni and unavoidable impurities, the resulting Ni-based alloy diaphragm has high strength and high hardness, and also has excellent spring properties and corrosion resistance. As a result, we have obtained research results that can be used to reduce the thickness and increase the area.

The present invention has been made on the basis of the above-mentioned research results. The diaphragm of the diaphragm valve is provided with: Cr: 17 to 25%, Mo: 17 to 22%, Ta: 1.1 to 3.4. %, Al: 0.1-0.8%, and, if necessary, Fe: 0.1-1%,
, The balance being composed of a Ni-based alloy having a composition consisting of Ni and inevitable impurities, in addition to excellent spring properties and corrosion resistance, in addition to having high strength and high hardness. .

Next, the reason why the composition of the Ni-based alloy constituting the Ni-based alloy diaphragm of the present invention is limited as described above will be described. (A) Cr The Cr component forms a base austenitic phase together with Ni to improve corrosion resistance, and a TCP phase which is finely precipitated in the base by heat treatment after cold rolling (between Mo, Ni and Cr). Compound) to improve the strength and hardness, but if the content is less than 17%, the desired effect of improving the effect cannot be obtained, while the content is 25%
If the content exceeds the range, the moldability will be reduced, and it will be difficult to mold the diaphragm. Therefore, the content is set to 17 to 25%, preferably 18 to 21%.

(B) Mo The Mo component has a function of improving the corrosion resistance by forming a solid solution in the base material and improving the strength and hardness by forming a TCP phase as described above. %,
In particular, the formation of the TCP phase becomes insufficient, and the desired strength and hardness improvement effects cannot be obtained. On the other hand, if the content exceeds 22%, the cold workability decreases, so that
The content was determined to be 17 to 22%, preferably 18 to 21%.

(C) Ta The Ta component has a function of improving the corrosion resistance by forming a solid solution in the base material, but if its content is less than 1.1%, the desired effect of improving the corrosion resistance cannot be obtained. If the content exceeds 3.4%, the spring property will be reduced.
It was determined to be 5%.

(D) Al Al has a deoxidizing effect and an effect of improving the strength by forming a solid solution in a base material. If the content is less than 0.1%, the desired strength improving effect is obtained. On the other hand, if the content exceeds 0.8%, the corrosion resistance decreases, so that the content is 0.1 to 0.8%, preferably 0.1 to 0. It was set at 4%.

(E) Fe Since the Fe component has a function of improving the hot workability by forming a solid solution in the base material, it is contained as necessary. If the desired effect is not obtained in the action, and if the content exceeds 1%, the corrosion resistance will be reduced.
%, Preferably 0.2 to 0.6%.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A Ni-based alloy diaphragm according to the present invention will be specifically described with reference to examples. First, using a normal high-frequency melting furnace, primary melting is performed in a melting atmosphere of Ar atmosphere, and the molten metal is cast into a mold to form an ingot having a size of diameter: 60 mm × length: 200 mm. Remelting was performed using an electroslag melting apparatus to form an ingot having a diameter of 100 mm composed of a Ni-based alloy having the composition shown in Table 1, and the ingot was added with 115
With the homogenizing heat treatment performed at a predetermined temperature in the range of 0 to 1250 ° C. for 10 hours, 1000 to 125
Hot forging and hot rolling are performed at a predetermined temperature in the range of 0 ° C. to form a hot-rolled sheet having a thickness of 1.6 mm.
In a state where the solution treatment is performed at a predetermined temperature within a range of 50 to 1250 ° C. for 30 minutes, cold rolling is started, and if necessary, a predetermined temperature within a range of 1150 to 1250 ° C. Cold rolling is performed while performing an annealing treatment under the condition of holding for 30 minutes, and the final cold rolling reduction is a predetermined rolling reduction within a range of 20 to 80% to obtain a cold-rolled sheet having a thickness of 0.15 mm, Further, the cold-rolled sheet is subjected to a precipitation heat treatment at a predetermined temperature within a range of 570 to 630 ° C. for a predetermined time within a range of 1 to 24 hours, and then subjected to a precipitation heat treatment under rapid cooling conditions. A structure in which the TCP phase was dispersed and distributed was finally punched out by pressing with wet polishing to remove oxides on the surface, so that each had a size of diameter: 20 mm × thickness: 0.13 mm. The diaphragm material of the present invention 1-1 And was a conventional diaphragm materials produced respectively.

With respect to the various diaphragm materials obtained as a result, the longitudinal elastic modulus and the transverse elastic modulus are measured for the purpose of evaluating the spring property, the tensile strength and the fatigue strength are measured for the purpose of evaluating the strength, and the hardness is measured. The Vickers hardness was measured, and the corrosion resistance was 36% H at a temperature of 60 ° C.
Evaluation was made by measuring the weight loss after immersion in a Cl aqueous solution, a 50% HBr aqueous solution, and a 50% HF aqueous solution for 24 hours. Table 2 shows the results of these measurements.

[0013]

[Table 1]

[0014]

[Table 2]

[0015]

According to the results shown in Tables 1 and 2, the diaphragm materials 1 to 12 of the present invention have excellent spring properties and corrosion resistance almost equivalent to those of the conventional diaphragm material, and have higher strength and higher hardness. It is clear that As described above, the Ni-based alloy diaphragm according to the present invention has spring strength and corrosion resistance required for the diaphragm and further has higher strength and hardness, and therefore is sufficient for reducing the thickness and increasing the area of the diaphragm. It can respond to satisfaction.

Claims (2)

[Claims] 1. The composition contains, by weight%, 17 to 25% of Cr, 17 to 22% of Mo, 1.1 to 3.4% of Ta, and 0.1 to 0.8% of Al. Is made of a Ni-based alloy having a composition of Ni and unavoidable impurities. A diaphragm made of a Ni-based alloy for a diaphragm valve having high strength and high hardness. 2. In% by weight, Cr: 17 to 25%, Mo: 17 to 22%, Ta: 1.1 to 3.4%, Al: 0.1 to 0.8%. , Fe: 0.1-1%, the balance being made of a Ni-based alloy having a composition consisting of Ni and inevitable impurities, made of a Ni-based alloy for a diaphragm valve having high strength and high hardness. Diaphragm.