阅读说明：本技术 提高Hastelloy N合金ΣCSL晶界比例的工艺方法 (Process method for improving Hastelloy N alloy Sigma CSL crystal boundary proportion ) 是由 白琴 刘黎明 夏爽 陶新 孔洁 周邦新 于 2021-06-11 设计创作，主要内容包括：本发明公开了一种提高Hastelloy N合金低ΣCSL晶界比例的工艺方法,将Hastelloy N合金冷轧加工30-70％,然后在1020-1200℃退火5-60min,以水淬的方式快速冷却至室温。而后在垂直原冷轧方向进行30-70％的冷轧加工,在相同的温度退火同样的时间后水淬至室温。然后再对样品进行3-15％的冷加工变形,在1020-1200℃退火3-120min并水淬快速冷却至室温。可得到Σ≤29的低ΣCSL晶界比例高于70％的HastelloyN合金。本工艺不仅不需改变合金成分,而且与现有其他工艺相比,不需要长时间退火,操作容易,具有十分明显的经济效益。(The invention discloses a process method for improving the low sigma CSL grain boundary proportion of Hastelloy N alloy, which comprises the steps of cold rolling and processing the Hastelloy N alloy by 30-70%, then annealing at 1020-. Then cold rolling processing is carried out for 30-70% in the direction vertical to the original cold rolling direction, and water quenching is carried out to the room temperature after annealing at the same temperature for the same time. Then, the sample is subjected to 3-15% cold working deformation, annealed at 1020-1200 ℃ for 3-120min and rapidly cooled to room temperature by water quenching. The Hastelloy N alloy with the low sigma CSL grain boundary proportion of more than 70 percent and the sigma is less than or equal to 29 can be obtained. The process does not need to change the alloy components, and compared with other existing processes, the process does not need to anneal for a long time, is easy to operate and has very obvious economic benefit.)

1. A process method for improving Hastelloy N alloy Sigma CSL grain boundary proportion is characterized by comprising the following steps:

a. carrying out primary cold rolling on the Hastelloy N alloy at room temperature, and controlling the deformation amount to be 30-70%;

b. after the Hastelloy N alloy is subjected to the primary cold rolling deformation in the step a, primary annealing is carried out on the deformed alloy, the temperature is kept for 5-60min at the primary annealing temperature of 1020-1200 ℃, and then the Hastelloy N alloy is rapidly cooled to the room temperature through water quenching;

c. c, performing cold rolling deformation on the alloy subjected to primary annealing in the step b again at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 30-70%, and performing secondary cold rolling;

d. after the alloy is subjected to the secondary cold rolling deformation in the step c, carrying out secondary annealing on the deformed alloy, keeping the temperature for 5-60min at the annealing temperature of 1020-1200 ℃, and then carrying out water quenching to rapidly cool the alloy to the room temperature;

e. d, performing cold working deformation on the alloy subjected to secondary annealing in the step d again at room temperature, and finishing the cold working process by adopting a cold rolling, stretching or other deformation modes and controlling the deformation amount to be 3-15%;

f. and e, after the cold working deformation of the alloy in the step e is completed, annealing the deformed alloy again, preserving the heat for 3-120min at the annealing temperature of 1020-1200 ℃, and then rapidly cooling the alloy to room temperature through water quenching to obtain the alloy with the low sigma CSL crystal boundary proportion not less than 70%, wherein the sigma is not more than 29.

2. The GBE process method for increasing the grain boundary proportion of an alloy low-sigma CSL according to claim 1, wherein: repeating the steps a-d at least once to perform cross rolling and intermediate annealing in preparation for steps e and f.

3. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: in the step a, the Hastelloy N alloy is subjected to primary cold rolling at room temperature, and the deformation amount is controlled to be 40-70%.

4. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: in the step b, after the Hastelloy N alloy is subjected to primary cold rolling deformation, primary annealing is carried out on the deformed alloy, the temperature is kept for 30-60min at the primary annealing temperature of 1177-1200 ℃, and then water quenching is carried out to rapidly cool the Hastelloy N alloy to the room temperature.

5. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: and c, performing secondary cold rolling deformation on the alloy subjected to primary annealing at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 50-70%, and performing secondary cold rolling.

6. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: in the step d, after the alloy is subjected to secondary cold rolling deformation, secondary annealing is carried out on the deformed alloy, the temperature is kept at the annealing temperature of 1100-1200 ℃ for 30-60min, and then water quenching is carried out to rapidly cool the alloy to the room temperature.

7. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: and in the step e, performing cold working deformation on the alloy subjected to secondary annealing again, controlling the deformation amount to be 5-15%, and finishing the cold working process.

8. The GBE process method for increasing grain boundary ratio of low sigma CSL of an alloy according to claim 1 or 2, wherein: in the step f, after the cold working deformation of the alloy is completed, annealing is performed again on the deformed alloy, the heat is preserved for 20-120min at the annealing temperature of 1170-1200 ℃, and then the alloy is rapidly cooled to the room temperature through water quenching, so that the alloy with the low sigma CSL grain boundary proportion not less than 70% is obtained.

Technical Field

The invention relates to a grain boundary engineering process method for improving the grain boundary proportion of a metal material low sigma CSL, in particular to a grain boundary engineering process method for a low-layer fault energy face-centered cubic metal material containing a large amount of primary carbides or brittle and hard inclusions, which is applied to the technical field of deformation and heat treatment processes of metal materials.

Background

Hastelloy N is a solid-solution-strengthened nickel-based alloy, has excellent mechanical property, high-temperature oxidation resistance, corrosion resistance and irradiation resistance, and is mainly used as a structural material in a molten salt reactor. The nuclear fuel in the molten salt reactor is carried into the reactor by high-temperature molten salt, and the structural material in the reactor is directly contacted with the flowing high-temperature molten salt. The fission product Te generated in the molten salt reactor can cause cracking of Hastelloy N alloy, the fission product Te enters the alloy through a common large-angle grain boundary and can cause intercrystalline embrittlement of the Hastelloy N alloy, the cracking phenomenon along the grain boundary occurs after stress, and the mechanical property of the alloy is greatly reduced. Therefore, the problem of environmental failure of critical structural materials is a bottleneck that restricts the development of molten salt stacks. The fission product Te diffuses along the general high-angle grain boundary, while the diffusion of Te is not observed at the twin grain boundary, so that the influence of Te on the intergranular cracking of the alloy can be effectively reduced by increasing the proportion of the twin grain boundary.

Watanabe proposed the concept of Grain Boundary design and control in 1984, and developed into the field of Grain Boundary Engineering (GBE) research in the last 90 th century. In the low-stacking fault energy face-centered cubic metal material, the adequate development of annealing twin crystal and multiple twin crystal processes can be promoted through appropriate deformation and heat treatment processes, and the improvement of sigma 3, sigma 9 and other sigma 3 is obviously improvedⁿLow Σ CSL grain boundary ratio of grain boundary (n ═ 1,2,3) type. Superposing a position Lattice, i.e. a coordinate Site Lattice; a low Σ CSL grain boundary means a CSL grain boundary where Σ is not more than 29, Σ: reciprocal of the density of the superposed positions of the crystal grain lattices on both sides of the grain boundary. In the low sigma CSL grain boundary, particularly the sigma 3 grain boundary, the structure order degree is high, the interface energy is low, and the performance is superior to that of the common large-angle grain boundary. The Hastelloy N alloy is also a low-stacking fault energy face-centered cubic metal material, the low sigma CSL grain boundary proportion of the Hastelloy N alloy material can be greatly increased through GBE, the grain boundary characteristic distribution is controlled, the Te-induced intergranular brittle cracking resistance of the material is improved, and other properties related to the grain boundary, such as intergranular corrosion resistance, of the material can also be improved.

However, Hastelloy N alloy has a high Mo content and is easily coarsened when solidified after smeltingLarge Ni₃Mo₃M of type C₆C primary carbide, which is harder and more brittle than the matrix, has a size of about several microns. The dissolution temperature of the carbide exceeds 1300 ℃, and the conventional solution heat treatment mode is not easy to eliminate. Such primary carbides may be present in a string-like distribution in a conventional rolling process, oriented parallel to the rolling direction, which may result in a high strain zone in the matrix near the string-like carbides. In the deformation and heat treatment process of GBE, the string-shaped carbide influences the formation and evolution of the low sigma CSL crystal boundary by influencing the recrystallization nucleation and growth process. Therefore, it is necessary to reduce the size of primary carbides and change the distribution characteristics of the primary carbides in the deformation and heat treatment processes to effectively increase the low sigma CSL grain boundary ratio and successfully implement GBE. The existing GBE process technology in the existing scientific and technological literature cannot overcome the influence of the serial distribution of primary carbides in the material on the generation of low sigma CSL crystal boundaries and the evolution process.

Disclosure of Invention

In order to solve the prior art problems of the prior Hastelloy N alloy in improving the low sigma CSL crystal boundary proportion, the invention aims to overcome the defects in the prior art, and provides a process method for improving the Hastelloy N alloy sigma CSL crystal boundary proportion, wherein the low sigma CSL crystal boundary proportion of the Hastelloy N alloy is improved to more than 70%, so that the carbide is distributed more uniformly, the influence of the carbide on crystal boundary evolution is reduced, the annealing heat treatment time is shortened, the quality of a low-layer fault energy face-centered cubic metal material containing a large amount of primary carbide or brittle and hard inclusions is improved, the energy consumption is saved, and the cost is reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

a process method for improving Hastelloy N alloy Sigma CSL grain boundary proportion comprises the following steps:

a. carrying out primary cold rolling on the Hastelloy N alloy at room temperature, and controlling the deformation amount to be 30-70%;

b. after the Hastelloy N alloy is subjected to the primary cold rolling deformation in the step a, primary annealing is carried out on the deformed alloy, the temperature is kept for 5-60min at the primary annealing temperature of 1020-1200 ℃, and then the Hastelloy N alloy is rapidly cooled to the room temperature through water quenching;

c. c, performing cold rolling deformation on the alloy subjected to primary annealing in the step b again at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 30-70%, and performing secondary cold rolling;

d. after the alloy is subjected to the secondary cold rolling deformation in the step c, carrying out secondary annealing on the deformed alloy, keeping the temperature for 5-60min at the annealing temperature of 1020-1200 ℃, and then carrying out water quenching to rapidly cool the alloy to the room temperature;

e. d, performing cold working deformation on the alloy subjected to secondary annealing in the step d again at room temperature, and finishing the cold working process by adopting a cold rolling, stretching or other deformation modes and controlling the deformation amount to be 3-15%;

f. and e, after the cold working deformation of the alloy in the step e is completed, annealing the deformed alloy again, preserving the heat for 3-120min at the annealing temperature of 1020-1200 ℃, and then rapidly cooling the alloy to room temperature through water quenching to obtain the alloy with the low sigma CSL crystal boundary proportion not less than 70%, wherein the sigma is not more than 29.

Preferably, the steps of a-d are repeated at least once to carry out cross rolling and an intermediate annealing in preparation for steps e and f.

Preferably, in the step a, the Hastelloy N alloy is subjected to primary cold rolling at room temperature, with a deformation amount controlled to be 40-70%.

Preferably, in the step b, after the Hastelloy N alloy is subjected to primary cold rolling deformation, the deformed alloy is subjected to primary annealing, the temperature is kept at the primary annealing temperature of 1177-1200 ℃ for 30-60min, and then the Hastelloy N alloy is rapidly cooled to the room temperature through water quenching.

Preferably, in the step c, the alloy subjected to the primary annealing is subjected to cold rolling deformation again at room temperature, the direction perpendicular to the primary cold rolling direction is ensured, the deformation amount is controlled to be 50-70%, and secondary cold rolling is performed.

Preferably, in the step d, after the alloy is subjected to secondary cold rolling deformation, the deformed alloy is subjected to secondary annealing, the temperature is kept at the annealing temperature of 1100-1200 ℃ for 30-60min, and then the alloy is rapidly cooled to the room temperature through water quenching.

Preferably, in the step e, the alloy after the secondary annealing is subjected to cold working deformation again, the deformation amount is controlled to be 5-15%, and the cold working process is completed.

Preferably, in the step f, after the cold working deformation of the alloy is completed, the deformed alloy is annealed again, the temperature is maintained at 1170-1200 ℃ for 20-120min, and then the alloy is rapidly cooled to room temperature through water quenching, so that the alloy with the low sigma CSL grain boundary proportion not less than 70% is obtained.

The invention mainly aims at Hastelloy N alloy, determines a deformation and annealing process, and obtains a material with the low sigma CSL (according to the Palombo-Aust standard) grain boundary proportion reaching more than 70%. The material processed by the traditional process has the low sigma CSL grain boundary proportion of about 20-40%.

The GBE process method can greatly improve the proportion of the low sigma CSL crystal boundary on the premise of not changing the alloy components, reduce the influence of primary string-shaped carbide on the generation and evolution of the low sigma CSL crystal boundary in the Hastelloy N alloy, and achieve the purpose of improving the performance related to the crystal boundary, such as intergranular corrosion resistance, Te resistance to intergranular brittle fracture performance and the like.

In step a, the alloy includes, but is not limited to Hastelloy N alloy, mainly a low-stacking fault energy face-centered cubic metal material containing a large amount of primary carbides or brittle, hard inclusions.

Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:

1. the invention carries out 30-70% cold rolling processing and 1020-1200 ℃ annealing on the alloy, and changes the direction rolling and secondary annealing, aiming at destroying the string distribution of the primary carbide, leading the carbide distribution to be finer and dispersed, obtaining the grain size which is relatively fine and evenly distributed, and removing the redundant deformation energy storage in the alloy;

2. the invention carries out cold processing deformation of 3-15% at room temperature, ensures that the deformation is accurate in the range, and carries out annealing at 1020-1200 ℃ after cold processing;

3. the invention is achieved byThe process combination can obviously improve sigma 3 in the alloyⁿThe grain boundary (N ═ 1,2,3) ratio increases the overall low sigma CSL grain boundary ratio of the Hastelloy N alloy material.

Drawings

FIG. 1 is a comparison of the low sigma CSL grain boundary ratio of Hastelloy N alloy before (A) and after (B) processing according to one embodiment of the present invention.

Fig. 2 is a comparison of the low sigma CSL grain boundary profile of Hastelloy N alloy before (a) and after (b) processing according to one embodiment of the present invention.

FIG. 3 is a gold phase diagram of Hastelloy N alloy after various processing steps in accordance with an embodiment of the present invention. (a) The gold phase diagram of the sample subjected to primary cold rolling annealing is shown; (b) is a sample metallographic image after two times of cross rolling annealing; (c) is a gold phase diagram of a sample treated by the process.

FIG. 4 is a graph of the distribution of low sigma CSL grain boundary characteristics of Hastelloy N alloy after being processed by the second process of the present invention.

FIG. 5 is a graph of the distribution of low sigma CSL grain boundary characteristics of Hastelloy N alloy after three processes in accordance with an embodiment of the present invention.

Detailed Description

The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:

the first embodiment is as follows:

in this embodiment, a process for increasing the grain boundary ratio of a Hastelloy N alloy sigma CSL includes the following steps:

a. carrying out primary cold rolling on the Hastelloy N alloy at room temperature, and controlling the deformation amount to be 40%;

b. after the Hastelloy N alloy is subjected to the primary cold rolling deformation in the step a, primary annealing is carried out on the deformed alloy, the temperature is kept for 30min at the primary annealing temperature of 1177 ℃, and then water quenching is carried out to rapidly cool the Hastelloy N alloy to the room temperature;

c. c, performing secondary cold rolling deformation on the alloy subjected to primary annealing in the step b at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 50%, and performing secondary cold rolling;

d. after the alloy is subjected to the secondary cold rolling deformation in the step c, carrying out secondary annealing on the deformed alloy, keeping the temperature at the annealing temperature of 1100 ℃ for 30min, and then carrying out water quenching to rapidly cool the alloy to the room temperature;

e. d, performing cold working deformation on the alloy subjected to secondary annealing in the step d again at room temperature, and finishing the cold working process by adopting a cold rolling, stretching or other deformation mode and controlling the deformation amount to be 5%;

f. and e, after the cold-working deformation of the alloy in the step e is completed, annealing the deformed alloy again, keeping the temperature for 20min at the annealing temperature of 1170 ℃, and then rapidly cooling the alloy to room temperature by water quenching to obtain the alloy with the low sigma CSL grain boundary proportion of sigma less than or equal to 29 reaching more than 70%.

Experimental test analysis:

the Hastelloy N alloy which is not processed by the process of the embodiment is used as a sample A, and the Hastelloy N alloy which is processed by the process of the embodiment is used as a sample B.

And (3) measuring the sample A and the sample B by adopting an EBSD (Electron Back scattering Diffraction) method, wherein the low sigma CSL grain boundary is counted according to the Palumbo-Aust standard. The EBSD method determined that the low sigma CSL grain boundary ratio in sample a was 49.8%, and the low sigma CSL grain boundary ratio in sample B was 75.7%, as shown in fig. 1. Fig. 1 is a graph of the low Σ CSL grain boundary ratio of sample a and sample B. In this embodiment, a deformation and annealing process is determined for Hastelloy N alloy, and a material with a low sigma CSL grain boundary ratio of 75.7% is obtained, whereas a material without the process of this embodiment has a low sigma CSL grain boundary ratio of 49.8%.

FIG. 2 is a plot of the grain boundary characteristics of the Hastelloy N alloy before and after treatment by the process of this example. As can be seen from fig. 2(a), in the sample that is not processed by the process of this embodiment, the grain boundary characteristic distribution is affected by the carbide in the alloy, more and fine grains are generated around the carbide, and the evolution process of the grain boundary characteristic distribution is affected in the recrystallization process, so that larger grain clusters are difficult to form, and further, the special grain boundary proportion of the alloy is reduced. The Hastelloy N alloy sample treated by the process of the embodiment has more uniform carbide distribution, reduces the influence of the carbide on grain boundary evolution, and greatly improves the special grain boundary proportion of the alloy, as shown in FIG. 2 (b).

FIG. 3 is a gold phase diagram of an alloy sample after being processed by different process steps. FIG. 3(a) is a phase diagram of the alloy of the sample after the initial cold rolling annealing of this example, in which the alloy has a large amount of primary carbides and is distributed in a string shape along the rolling direction. Fig. 3(b) is a gold phase diagram of the sample after the annealing of the second vertical rolling in the present embodiment, and after the second vertical cross rolling, the string-like carbides distributed along the rolling direction are dispersed to some extent and distributed relatively uniformly in the alloy. Fig. 3(c) is a gold phase diagram of the sample after the processing by the process of this embodiment, and fine and dispersed carbides in the sample do not have great influence on the distribution, migration and evolution of the grain boundary characteristics.

The process method of the embodiment does not need to change the components of the materials, and compared with the prior similar process, the process method does not need to carry out long-time annealing and is easy to operate, thereby having very obvious economic benefit.

Example two:

this embodiment is substantially the same as the first embodiment, and is characterized in that:

a process method for improving Hastelloy N alloy Sigma CSL grain boundary proportion comprises the following steps:

a. carrying out primary cold rolling on the Hastelloy N alloy at room temperature, and controlling the deformation amount to be 70%;

b. after the Hastelloy N alloy is subjected to the primary cold rolling deformation in the step a, primary annealing is carried out on the deformed alloy, the temperature is kept for 5min at the primary annealing temperature of 1200 ℃, and then water quenching is carried out to rapidly cool the Hastelloy N alloy to the room temperature;

c. c, performing secondary cold rolling deformation on the alloy subjected to primary annealing in the step b at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 70%, and performing secondary cold rolling;

d. after the alloy is subjected to the secondary cold rolling deformation in the step c, carrying out secondary annealing on the deformed alloy, keeping the temperature at the annealing temperature of 1200 ℃ for 5min, and then carrying out water quenching to rapidly cool the alloy to the room temperature;

e. d, performing cold working deformation on the alloy subjected to secondary annealing in the step d again at room temperature, and finishing the cold working process by adopting a cold rolling, stretching or other deformation mode and controlling the deformation amount to be 15%;

f. and e, after the cold working deformation of the alloy in the step e is completed, annealing the deformed alloy again, keeping the temperature at the annealing temperature of 1200 ℃ for 3min, and then rapidly cooling the alloy to room temperature by water quenching to obtain the alloy with the low sigma CSL grain boundary proportion of sigma less than or equal to 29 reaching more than 70%.

Experimental test analysis:

the Hastelloy N alloy treated by the process of this example was used as sample C, and this example measured the sample by EBSD (Electron back scattering Diffraction) method, and the low sigma CSL grain boundaries were counted according to Palumbo-Aust standard. The low Σ CSL grain boundary proportion in the sample was 76.9% as determined by the EBSD method, as shown in fig. 4. The deformation and annealing process is determined for Hastelloy N alloy, the obtained alloy material with the low sigma CSL grain boundary proportion of sigma less than or equal to 29 reaching more than 70% is obviously higher than that of the material which is not treated by the process of the embodiment, the process method of the embodiment does not need to change the components of the material, and compared with the existing similar process, the process does not need to be annealed for a long time, is easy to operate, and has very obvious economic benefit.

Example three:

this embodiment is substantially the same as the previous embodiment, and is characterized in that:

a process method for improving Hastelloy N alloy Sigma CSL grain boundary proportion comprises the following steps:

a. carrying out primary cold rolling on the Hastelloy N alloy at room temperature, and controlling the deformation amount to be 30%;

b. after the Hastelloy N alloy is subjected to the primary cold rolling deformation in the step a, primary annealing is carried out on the deformed alloy, the temperature is kept for 60min at the primary annealing temperature of 1020 ℃, and then water quenching is carried out to rapidly cool the Hastelloy N alloy to the room temperature;

c. c, performing secondary cold rolling deformation on the alloy subjected to primary annealing in the step b at room temperature, ensuring the alloy to be vertical to the primary cold rolling direction, controlling the deformation amount to be 30%, and performing secondary cold rolling;

d. after the alloy is subjected to the secondary cold rolling deformation in the step c, carrying out secondary annealing on the deformed alloy, keeping the temperature at the annealing temperature of 1020 ℃ for 60min, and then carrying out water quenching to rapidly cool the alloy to the room temperature;

e. d, performing cold working deformation on the alloy subjected to secondary annealing in the step d again at room temperature, and finishing the cold working process by adopting a cold rolling, stretching or other deformation mode and controlling the deformation amount to be 3%;

f. and e, after the cold working deformation of the alloy in the step e is completed, annealing the deformed alloy again, keeping the temperature at the annealing temperature of 1020 ℃ for 120min, and then rapidly cooling the alloy to room temperature by water quenching to obtain the alloy with the low sigma CSL grain boundary proportion of sigma less than or equal to 29 reaching more than 70%.

Experimental test analysis:

the Hastelloy N alloy treated by the process of this example was used as sample D, in this example, the sample was measured by EBSD (Electron back scattering Diffraction) method, and the low sigma CSL grain boundaries were counted according to Palumbo-Aust standard. The low Σ CSL grain boundary proportion in the sample was 70.6% as determined by the EBSD method, as shown in fig. 5. The deformation and annealing process is determined for Hastelloy N alloy, the obtained alloy material with the low sigma CSL grain boundary proportion of sigma less than or equal to 29 reaching more than 70% is obviously higher than that of the material which is not treated by the process of the embodiment, the process method of the embodiment does not need to change the components of the material, and compared with the existing similar process, the process does not need to be annealed for a long time, is easy to operate, and has very obvious economic benefit.

The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention should be replaced with equivalents as long as the object of the present invention is met, and the technical principle and the inventive concept of the present invention are not departed from the scope of the present invention.