WO2018028093A1

WO2018028093A1 - Casting material used in nuclear turbine and preparation method therefor

Info

Publication number: WO2018028093A1
Application number: PCT/CN2016/108089
Authority: WO
Inventors: 孙飞; 赵勇; 埃里克斯⋅高登
Original assignee: 苏州列治埃盟新材料技术转移有限公司
Priority date: 2016-08-09
Filing date: 2016-11-30
Publication date: 2018-02-15
Also published as: CN106282653A

Abstract

Disclosed is a preparation method for a casting material used in a nuclear turbine. The preparation method comprises the following steps: placing, by mass percent, 11.5% - 13.5% of aluminum, 2% - 5.5% of iron, 1.5% - 3.5% of manganese, 0.3% - 1.5% of nickel and the balance of copper into a main frequency induction furnace, heating same to 1,100 degrees centigrade until same has completely melted, and then maintaining the temperature, and adding silicon carbide ceramic particles with a purity of 99.9% and rare earth element lanthanum or cerium thereto.

Description

Casting material applied to nuclear steam turbine and manufacturing method thereof

Technical field

The invention relates to the field of alloy materials, in particular to a casting material applied to a nuclear steam turbine and a manufacturing method thereof.

Background technique

Bronze materials have good ductility and forgeability, so they are widely used. They are mainly used in the technical field of nuclear steam turbines, specifically for forging various types of valve blocks and wear-resistant pump blocks. However, with the vigorous development of the nuclear power industry, the market demand for more and better materials, due to the defects caused by the forging process, the bronze ingots currently used have become increasingly unable to meet the high-standard pump valve alloy ingots at home and abroad. Demand. In addition, due to the internal structure of the material, the bronze material cast by sand casting is highly prone to the inclusion of pore surface and is not easy to be overmolded.

Summary of the invention

In order to solve the above problems, the present invention provides a casting material applied to a nuclear steam turbine and a manufacturing method thereof, which can improve the strength and hardness of the material, and can avoid cracking of the cast material due to forging, and reduce the material in the material. The porosity generated during the casting process.

In order to achieve the above object, the technical solution adopted by the present invention is as follows:

A method for preparing a casting material for a nuclear steam turbine, comprising the following steps:

1), in terms of mass percentage, aluminum: 11.5 ~ 13.5%, iron: 2 ~ 5.5%, manganese: 1.5 ~ 3.5%, nickel: 0.3 ~ 1.5%, copper: the balance is placed in the power frequency electric furnace, heated to 1100 degrees after complete melting and insulation;

2) Add REE or lanthanum: 1.5 to 2.5% by mass percentage In the insulated alloy solution, the vibration device and the stirring device are turned on, the vibration frequency of the vibration device is: 10 times/second, the stirring rate of the stirring device is: 300 rpm, and the stirring time is: 10 to 15 minutes;

3), according to the mass percentage, the purity of 99.9% of silicon carbide particles: 3 ~ 5%, added to the alloy solution, while stirring again, the stirring rate is 200 rev / min, stirring time 5 ~ 10 minutes;

4) Transfer the stirred alloy solution to the casting holding furnace, and stir for the third time, the stirring time is 15-20 minutes, and the speed is 350 rpm;

5), the stirred alloy solution is allowed to stand for 3 to 5 minutes, and sampled and tested. It has been determined that the composition is within the set range. After the components are qualified, the melt is directly introduced into the crystallizer by a draft tube, and the mold is lubricated. Oil, the furnace is covered with carbon black of 3 ~ 5 cm thickness to reduce the chance of oxidation and slag;

6), casting by horizontal casting method, the outer diameter of the alloy ingot is 185 mm, the casting speed is 4 m / h, the height of the crystallizer is 190 mm, the cooling water pressure is 0.15 MPa, and the temperature of the ingot is controlled to 1200-1250 degrees. ;

7) In the horizontal casting process, the distance between the outer circle of the bottom of the graphite sleeve and the wall of the crystallizer is about 10-15 mm. The exposed metal liquid surface enters the crystallizer under the condition of maintaining a certain static pressure, and the surface of the ingot is ingot. Micro-wavy, but relatively smooth, ingot length is 3010 mm / branch;

8), the long alloy ingot is sawn to a length of 1000 mm / support, the glazing machine removes surface oxide scale and various inclusions, the outer diameter is controlled to 180 mm, the tolerance is +/- 0.5 mm, and the package is stored. .

Further, the mass percentage of each component in the step 1) is: 3.5%, aluminum: 12.1%, iron: 3%, manganese: 1.8%, nickel: 0.4%, copper: balance, in the step 2) The mass percentage of niobium or tantalum is: 1.7%, and the mass percentage of silicon carbide particles in step 3) is: 3.5%.

Further, the mass percentage of each component in the step 1) is: aluminum: 12.8%, iron: 4.2%, manganese: 2.2%, nickel: 0.8%, copper: balance, bismuth or bismuth in the step 2) The mass percentage is: 1.9%, and the mass percentage of the silicon carbide particles in the step 3) is: 4%.

Further, the mass percentage of each component in the step 1) is: aluminum: 13.2%, iron: 5.1%, manganese: 3.4%, nickel: 1.3%, copper: balance, bismuth or bismuth in the step 2) Quality hundred The fraction is: 2.3%, and the mass percentage of the silicon carbide particles in the step 3) is: 4.5%.

The present invention also provides a casting material for use in a nuclear steam turbine, which is prepared by the aforementioned method.

The invention has the beneficial effects that the casting material for the nuclear steam turbine provided by the invention adds silicon carbide ceramic particles with a purity of 99.9% to the traditional bronze material to improve the hardness of the cast alloy material; and appropriately adds the corresponding rare earth The element 镧 or 铈 is used to further refine and improve the radial structure of the alloy internal material, so that the material can achieve the strength and hardness of the alloy material without further forging or heat treatment, and further satisfy the nuclear power turbine. Material requirements. At the same time, the cracking of the original alloy material due to forging is avoided, and the porosity of the material during the casting process is further reduced, thereby saving production cost and improving production efficiency.

detailed description

The technical solutions in the embodiments of the present invention are clearly and completely described below. It is apparent that the described embodiments are only a part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Example 1

1), according to aluminum: 12.1%, iron: 3%, manganese: 1.8%, nickel: 0.4%, copper: the mass percentage of the balance, the raw materials are placed, placed in a power frequency electric furnace, heated to 1100 degrees after complete melting And keep warm;

2), the rare earth element lanthanum or cerium: 1.7%, in mass percentage, added to the alloy solution being insulated, the vibration device and the stirring device are turned on, the vibration frequency of the vibration device is: 10 times/second, and the stirring rate of the stirring device is : 300 rpm, stirring time: 10 to 15 minutes;

3), the purity of 99.9% of silicon carbide: 3.5%, in mass percentage, added to the alloy solution, while stirring again, the stirring rate is 200 rev / min, stirring time 5 ~ 10 minutes;

5), the stirred alloy solution is allowed to stand for 3 to 5 minutes, and sampled and tested to determine the composition within the set range. After the components are qualified, the melt is directly introduced into the crystallizer by a draft tube, and the mold is lubricated. Oil, the furnace is covered with carbon black of 3 ~ 5 cm thickness to reduce the chance of oxidation and slag;

6), casting by horizontal casting method, the outer diameter of the alloy ingot is 185 mm, the casting speed is 4 m / h, the height of the crystallizer is 190 mm, the cooling water pressure is 0.15 MPa, and the temperature of the ingot is controlled to 1200 to 1250 degrees. ;

Example 2

Example 2 and Example 1 differ only in the raw material ratio, and the other aspects are the same. Therefore, only the differences will be explained below.

The percentage of each component in the step 1) was: aluminum: 12.8%, iron: 4.2%, manganese: 2.2%, nickel: 0.8%, copper: balance.

The mass percentage of the rare earth element lanthanum or cerium in step 2) is: 1.9%.

The mass percentage of silicon carbide in step 3) is: 4%.

According to the second embodiment, substantially the same effects as those of the first embodiment can be obtained.

Example 3

Example 3 and Examples 1 and 2 differ only in the raw material ratio, and the other aspects are the same. Therefore, only the differences will be explained below.

The percentage of each component in the step 1) was: aluminum: 13.2%, iron: 5.1%, manganese: 3.4%, nickel: 1.3%, copper: balance.

The mass percentage of the rare earth element lanthanum or cerium in step 2) is: 2.3%.

The mass percentage of silicon carbide in step 3) is: 4.5%.

According to the third embodiment, substantially the same effects as those of the first and second embodiments can be achieved.

Material experimental data performance comparison table:

As can be seen from the above table, the hardness and strength of the cast alloy material are improved by the material cast by the present invention. At the same time, the porosity of the material during the casting process is further reduced, thereby saving production costs and improving production efficiency.

The above-mentioned embodiments are merely illustrative of the embodiments of the present invention, and the description thereof is not to be construed as limiting the scope of the invention. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the invention. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A method for preparing a casting material for a nuclear steam turbine, characterized in that it comprises the following steps:

1), in terms of mass percentage, aluminum: 11.5 ~ 13.5%, iron: 2 ~ 5.5%, manganese: 1.5 ~ 3.5%, nickel: 0.3 ~ 1.5%, copper: the balance is placed in the power frequency electric furnace, heated to 1100 degrees after complete melting and insulation;

2) According to the mass percentage, the rare earth element lanthanum or lanthanum: 1.5~2.5% is added to the alloy solution being insulated, and the vibration device and the stirring device are turned on. The vibration frequency of the vibration device is: 10 times/second, and the stirring device is stirred. The rate is: 300 rpm, and the stirring time is: 10 to 15 minutes;

3), according to the mass percentage, the purity of 99.9% of silicon carbide particles: 3 ~ 5%, added to the alloy solution, while stirring again, the stirring rate is 200 rev / min, stirring time 5 ~ 10 minutes;

4) Transfer the stirred alloy solution to the casting holding furnace, and stir for the third time, the stirring time is 15-20 minutes, and the speed is 350 rpm;

5), the stirred alloy solution is allowed to stand for 3 to 5 minutes, and sampled and tested. It has been determined that the composition is within the set range. After the components are qualified, the melt is directly introduced into the crystallizer by a draft tube, and the mold is lubricated. Oil, the furnace is covered with carbon black of 3 ~ 5 cm thickness to reduce the chance of oxidation and slag;

6), casting by horizontal casting method, the outer diameter of the alloy ingot is 185 mm, the casting speed is 4 m / h, the height of the crystallizer is 190 mm, the cooling water pressure is 0.15 MPa, and the temperature of the ingot is controlled to 1200-1250 degrees. ;

7) In the horizontal casting process, the distance between the outer circle of the bottom of the graphite sleeve and the wall of the crystallizer is about 10-15 mm. The exposed metal liquid surface enters the crystallizer under the condition of maintaining a certain static pressure, and the surface of the ingot is ingot. Micro-wavy, but relatively smooth, ingot length is 3010 mm / branch;

8), the long alloy ingot is sawn to a length of 1000 mm / support, the glazing machine removes surface oxide scale and various inclusions, the outer diameter is controlled to 180 mm, the tolerance is +/- 0.5 mm, and the package is stored. .
The method for preparing a casting material for use in a nuclear power steam turbine according to claim 1, wherein the mass percentage of each component in the step 1) is: 3.5%, aluminum: 12.1%, iron: 3%, manganese : 1.8%, nickel: 0.4%, copper: balance, the mass percentage of ruthenium or osmium in step 2) is: 1.7%, and the mass percentage of silicon carbide particles in step 3) is: 3.5%.
The method for preparing a casting material for a nuclear steam turbine according to claim 1, wherein the mass percentage of each component in the step 1) is: aluminum: 12.8%, iron: 4.2%, manganese: 2.2%, Nickel: 0.8%, copper: balance, the mass percentage of ruthenium or osmium in step 2) is: 1.9%, and the mass percentage of silicon carbide particles in step 3) is: 4%.
The method for preparing a casting material for a nuclear steam turbine according to claim 1, wherein the mass percentage of each component in the step 1) is: aluminum: 13.2%, iron: 5.1%, manganese: 3.4%, Nickel: 1.3%, copper: balance, the mass percentage of ruthenium or osmium in step 2) is: 2.3%, and the mass percentage of silicon carbide particles in step 3) is: 4.5%.
A casting material for use in a nuclear steam turbine, characterized in that the material is produced by the method according to any one of claims 1-4.