阅读说明：本技术 一种降低铍材残余应力的方法 (Method for reducing residual stress of beryllium material ) 是由 肖来荣 任鹏禾 赵小军 蔡圳阳 涂晓萱 张亚芳 于 2021-07-23 设计创作，主要内容包括：本发明涉及一种降低铍材残余应力的方法,属于粉末冶金材料加工领域。本发明通过对铍材采用拉应力时效处理和N级变温冷热循环稳定处理,实现铍材残余应力的下降,所述N大于等于2,所述冷热循环稳定处理时,冷却的温度低于1℃,加热处理的温度大于等于100℃且小于铍材的熔点,相邻两次冷处理的温度不同,和/或相邻两次热处理的温度不同。本发明操作简便,成本较低,工艺简单,应用本发明优化技术得到的铍材残余应力下降至-50～50MPa、室温放置一年尺寸变化小于0.002％。(The invention relates to a method for reducing residual stress of a beryllium material, and belongs to the field of powder metallurgy material processing. The method comprises the steps of performing tensile stress aging treatment and N-grade temperature-changing cold-hot circulation stabilization treatment on the beryllium material to reduce the residual stress of the beryllium material, wherein N is more than or equal to 2, the cooling temperature is lower than 1 ℃, the heating temperature is more than or equal to 100 ℃ and less than the melting point of the beryllium material during the cold-hot circulation stabilization treatment, and the temperatures of two adjacent cold treatments are different and/or the temperatures of two adjacent heat treatments are different. The method is simple and convenient to operate, low in cost and simple in process, the residual stress of the beryllium material obtained by applying the optimization technology is reduced to-50 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is less than 0.002%.)

1. A method for reducing residual stress of beryllium materials is characterized by comprising the following steps: the method comprises the steps of adopting tensile stress aging treatment and N-grade temperature-changing cold-hot circulation stabilizing treatment on the beryllium material to reduce the residual stress of the beryllium material, wherein N is more than or equal to 2, the cooling temperature is lower than 1 ℃, the heating temperature is more than or equal to 100 ℃ and less than the melting point of the beryllium material during the cold-hot circulation stabilizing treatment, and the temperatures of two adjacent cold treatments are different and/or the temperatures of two adjacent heat treatments are different.

2. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: the beryllium material is isostatic pressing beryllium material.

3. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: the mass percentage of beryllium in the beryllium material is more than or equal to 95 percent, preferably more than or equal to 98 percent.

4. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: the type of the raw material used in the beryllium material preparation is selected from one of Be-1, Be-2, Be-3 and Be-4.

5. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: firstly, carrying out tensile stress aging treatment on a beryllium material, wherein the tensile stress aging treatment comprises the following steps: the beryllium material is heated to 300-400 ℃, the temperature is kept for 4-24 hours, and tensile stress of 30-80 MPa is applied.

6. The method for reducing the residual stress of beryllium material as claimed in claim 5, wherein: and during the tensile stress aging treatment, controlling the temperature to be 300-360 ℃ and preserving the heat for 5-20 h.

7. The method for reducing the residual stress of beryllium material as claimed in claim 5, wherein: and during the tensile stress aging treatment, controlling the temperature to be 345-355 ℃, preserving the heat for 10-14 h, and applying the tensile stress of 45-55 MPa.

8. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: the method comprises the following steps of performing multi-stage temperature-changing cold-hot circulation stabilization treatment on a beryllium material, wherein the N-stage temperature-changing cold-hot circulation stabilization treatment comprises the following steps: cooling the beryllium material to-196 to-180 ℃, preserving heat for 60-180 min, then heating to 300-350 ℃, and preserving heat for 60-180 min; then, cooling the beryllium material to-110 to-90 ℃, preserving heat for 60 to 180min, then heating to 200 to 250 ℃, and preserving heat for 60 to 180 min; the beryllium material is cooled to-20-0 ℃, is subjected to heat preservation for 60-180 min, is heated to 100-150 ℃, is subjected to heat preservation for 60-180 min, and is finally cooled to the room temperature at the speed of 1-3 ℃/min.

9. The method for reducing the residual stress of beryllium material as claimed in claim 1, wherein: carrying out N-level temperature-changing cold-hot circulating stabilization treatment on the beryllium material, wherein the N-level temperature-changing cold-hot circulating stabilization treatment comprises the following steps: cooling the beryllium material to-196 ℃, preserving heat for 60-70 min, then heating to 310-330 ℃, and preserving heat for 60-90 min; then, cooling the beryllium material to-100 to-90 ℃, preserving heat for 60-70 min, then heating to 200-200 ℃, and preserving heat for 60-70 min; the beryllium material is cooled to-10-0 ℃, is subjected to heat preservation for 60-120 min, is heated to 115-125 ℃, is subjected to heat preservation for 60-120 min, and is finally cooled to the room temperature at the speed of 1-3 ℃/min.

Technical Field

The invention relates to a method for reducing residual stress of a beryllium material, and belongs to the field of powder metallurgy material processing.

Background

The metal beryllium is a strategic and decisive material, has excellent comprehensive properties such as high specific modulus, high specific strength, low density, low thermal expansion coefficient and the like, and is widely applied to the fields of instruments, inertial navigation systems, strategic weapon structural materials and the like. These parts have extremely high requirements on residual stress, but in practical application, particularly in high-temperature environment, any deformation may affect the residual stress state of the material and the stability, reliability and service life of the whole device

At present, the core of beryllium material preparation is a powder making process and an isostatic pressing process. The powder-making process is divided into an airflow impact method and an inert gas atomization method. The airflow impact powder making process is one new powder producing process based on the cold brittleness of metal, and has high speed and high pressure gas to bombard the beryllium target inside the crushing chamber with coarse grains, high pressure to atmosphere pressure, adiabatic expansion to lower the temperature of the beryllium target and the crushing chamber to room temperature or even below zero centigrade, and cooled grains being crushed through collision. The inert gas atomization powder preparation is characterized in that solid beryllium is melted in vacuum, the melted beryllium solution flows out through a small hole, then high-speed helium gas flow is used for blowing the melted beryllium solution (the beryllium has high heat capacity, and the helium is used for most probably obtaining fine-grain beryllium particles and an unstable rapid condensation structure), the beryllium solution is atomized and crushed into small droplets, and the spherical beryllium powder particles are obtained after cooling. The two powder-making processes can introduce the compressive stress caused by rapid cooling, so that the beryllium powder has the compressive stress with gradient change from the surface to the center. The isostatic pressing process of beryllium material is characterized by that the beryllium powder is filled into the steel sleeve, and after the processes of evacuation, degasification treatment and sealing welding, the isostatic pressing process is implemented, so that the beryllium powder can be uniformly pressed in all directions at the same time so as to obtain the beryllium material with uniform density distribution and high strength. The high pressure in the isostatic pressing process enables the beryllium material to obtain larger pressure stress from the outside and the inside. Therefore, the isostatic pressing beryllium material has larger compressive stress from the surface to the center, and is mainly introduced by powder making and an isostatic pressing process.

The existing beryllium material heat treatment method mainly comprises stress relief annealing, recrystallization annealing, cold-hot circulation treatment and solid solution aging treatment. The stress relief annealing temperature of the beryllium material is generally 760-800 ℃, the temperature is kept for 1-2 h, and the annealing is carried out under vacuum. The beryllium material is rolled and extruded, then the crystal lattice is distorted, the crystal grains are broken, the strength and the hardness are improved, but the further processing needs to be carried out with recrystallization annealing to soften the beryllium material. The recrystallization temperature of beryllium is related to the purity, the content of beryllium oxide, the dispersion degree and the cold working rate, and is generally between 760 ℃ and 900 ℃. The conventional beryllium material is generally treated at a temperature of 73 ℃ below zero for 10 minutes in a cold-hot cycle treatment, and then treated at a temperature of 100 ℃ for 10 minutes, and the treatment is repeated for 4 to 6 times so as to achieve the purpose of reducing the residual stress. The solid solution aging treatment of beryllium mainly aims at iron elements. The beryllium material is heated to a temperature above the solid solution line of iron and below the melting point of iron, the solid solubility of iron in beryllium is maximized, a supersaturated solid solution of iron is formed, iron is precipitated from the supersaturated solid solution during aging to form a precipitation strengthening phase, and the strength of beryllium is improved. Only part of residual stress can be eliminated by adopting conventional stress relief annealing treatment and cold-hot circulation treatment; the precipitated phase of the beryllium material can be effectively stabilized by adopting high-temperature solution treatment and aging, but the crystal grains can be coarsened, and residual stress is superposed in the cooling process, so that the aim of effectively removing the residual stress of the beryllium material cannot be fulfilled by adopting the conventional methods and processes such as stress relief annealing, cold and hot circulation, high-temperature solution, high-temperature aging and the like.

Overall, the residual stress of beryllium material is mainly affected by three aspects: firstly, in the process of beryllium material preparation, machining and heat treatment, macroscopic residual stress is generated due to the superposition of external stresses such as beryllium powder preparation stress, machining stress, thermal stress, deformation stress and the like. And secondly, in the service process, the beryllium undergoes temperature change, thermal stress is generated in a high-low temperature circulating environment or residual stress state change is caused by the changes of the beryllium subcell cell length, the subgrain boundary transition, the nanophase precipitation and redissolution, the dislocation density and other organizational structures due to the diffusion and aggregation of atoms and vacancies under a long-term high-temperature environment. And thirdly, in the long-term storage process, stress relaxation and release actions occur after the beryllium member is assembled to form an integral device.

The residual stress state of the beryllium material determines the dimensional stability of the beryllium material, and further determines key performance indexes of stability, precision, service life and the like of the beryllium material component. Therefore, reasonably regulating and controlling the residual stress of the beryllium material is an important way for obtaining the beryllium material with high dimensional stability so as to improve the precision and the service life of the device. Therefore, a method for efficiently reducing the residual stress of the beryllium material is researched, and the problem that the beryllium material needs to be solved urgently in the actual application and service process is solved.

Disclosure of Invention

In order to better control the residual stress of the beryllium material and further improve the dimensional stability of the beryllium material and the reliability and service life of a beryllium device, the invention provides a method for efficiently reducing the residual stress of the beryllium material. The specific technical scheme is as follows.

The invention relates to a method for reducing the residual stress of a beryllium material, which is characterized in that the residual stress of the beryllium material is reduced by adopting tensile stress aging treatment and N-grade temperature-variable cold-hot circulating stabilization treatment on the beryllium material, wherein N is more than or equal to 2, the cooling temperature is lower than 1 ℃, the heating temperature is more than or equal to 100 ℃ and less than the melting point of the beryllium material during the cold-hot circulating stabilization treatment, and the temperatures of two adjacent cold treatments are different and/or the temperatures of two adjacent heat treatments are different.

In the invention, the purpose of the treatment that the temperature of the two adjacent cold treatments is different and/or the temperature of the two adjacent heat treatments is different is to eliminate the residual stress existing in the material by overlapping the external stress for the beryllium material, so that the residual stress of the beryllium material is further relaxed, and the toughness of the beryllium material can be maintained on the premise of not reducing the strength and the hardness.

Preferably, the method for reducing the residual stress of the beryllium material is used, wherein the beryllium material is isostatic-pressed beryllium material.

Preferably, the method for reducing the residual stress of the beryllium material comprises the step of enabling the mass percentage of beryllium in the beryllium material to be greater than or equal to 95%, and more preferably greater than or equal to 98%.

Preferably, the type of the raw material used for preparing the beryllium material is selected from one of Be-1, Be-2, Be-3 and Be-4. Because the beryllium material does not have a uniform beryllium mark national standard, the beryllium material is obtained by processing beryllium beads. Therefore, the beryllium material in the patent is defined according to YS/T221-2011 beryllium metal bead, and the beryllium material is defined as a material with the specification of bars, tubes, blocks, plates, belts and the like, wherein the material is prepared by taking the beryllium beads with the brands of Be-1, Be-2, Be-3 and Be-4 as raw materials through powder metallurgy methods such as smelting, powder making, isostatic pressing or vacuum hot pressing, sintering and the like, and the content of Be element is not less than 98%.

The invention relates to a method for reducing the residual stress of a beryllium material, which comprises the following steps of firstly, carrying out tensile stress aging treatment on the beryllium material: the beryllium material is heated to 300-400 ℃, the temperature is kept for 4-24 hours, and tensile stress of 30-80 MPa is applied.

As a preferable scheme, the method for reducing the residual stress of the beryllium material is characterized in that the temperature is controlled to be 300-360 ℃ and the heat is preserved for 5-20 hours during the tensile stress aging treatment.

As a further preferable scheme, in the method for reducing the residual stress of the beryllium material, the temperature is controlled to be 345-355 ℃ and is kept for 10-14 h during the tensile stress aging treatment, and the tensile stress of 45-55 MPa is applied.

As a preferable scheme, the method for reducing the residual stress of the beryllium material comprises the following steps of performing N-level temperature-variable cold-hot circulation stabilization treatment on the beryllium material, wherein the N-level temperature-variable cold-hot circulation stabilization treatment comprises the following steps: cooling the beryllium material to-196 to-180 ℃, preserving heat for 60-180 min, then heating to 300-350 ℃, and preserving heat for 60-180 min; then, cooling the beryllium material to-110 to-90 ℃, preserving heat for 60 to 180min, then heating to 200 to 250 ℃, and preserving heat for 60 to 180 min; the beryllium material is cooled to-20-0 ℃, is subjected to heat preservation for 60-180 min, is heated to 100-150 ℃, is subjected to heat preservation for 60-180 min, and is finally cooled to the room temperature at the speed of 1-3 ℃/min.

As a further preferable aspect, the method for reducing the residual stress of the beryllium material of the present invention is a method for performing N-level temperature-variable cold-hot cycle stabilization treatment on the beryllium material, wherein the N-level temperature-variable cold-hot cycle stabilization treatment includes: cooling the beryllium material to-196 ℃, preserving heat for 60-70 min, then heating to 310-330 ℃, and preserving heat for 60-90 min; then, cooling the beryllium material to-100 to-90 ℃, preserving heat for 60-70 min, then heating to 200-200 ℃, and preserving heat for 60-70 min; the beryllium material is cooled to-10-0 ℃, is subjected to heat preservation for 60-120 min, is heated to 115-125 ℃, is subjected to heat preservation for 60-120 min, and is finally cooled to the room temperature at the speed of 1-3 ℃/min.

Compared with the prior art, the technical scheme of the invention has the following advantages:

as the beryllium material can generate and accumulate compressive stress in the early preparation processes of powder making, isostatic pressing and the like, and the stress difference exists between the core part and the surface layer. Firstly, stress aging treatment is adopted, and the proper tensile stress provided in the process can be effectively superposed with the residual stress of the beryllium material and slowly reduced. In addition, the provided external tensile stress can effectively promote impurity elements such as iron, nickel, cobalt, aluminum and the like in the beryllium material to diffuse to the crystal boundary, form discontinuous nanometer precipitates, pin the crystal boundary, improve the micro-yield strength of the beryllium material and reduce the micro residual stress caused by lattice distortion. The diffusion and precipitation of impurity atoms is a process of volume increase, the transformation is greatly limited in a compressive stress state, and the applied tensile stress can effectively promote the phase transformation, so that the microscopic residual stress caused by impurity elements is eliminated.

By adopting conventional stress relief annealing treatment and cold-hot circulation treatment, only part of macroscopic residual stress can be eliminated, and the problems of growth of sub-crystals, uneven cooling thermal stress and the like are easily caused in the process, so that the stress relief annealing effect of the beryllium material is limited. The invention carries out multi-stage temperature-changing cold-hot circulation stabilization treatment after stress aging, and is an effective way for improving the stability of residual stress. The multistage variable-temperature cold-hot circulation stabilizing treatment with appropriate parameters eliminates the residual stress of the material by superposing the external stress on the beryllium material for a certain time, so that the residual stress of the beryllium material is further relaxed, and the toughness of the beryllium material can be maintained on the premise of not reducing the strength and the hardness. Meanwhile, the residual stress state of the beryllium material can be estimated according to the permanent deformation of each stage of cold-hot circulation, when the permanent deformation of a certain stage of cold-hot circulation is less than 0.0001%, the residual stress of the beryllium material is about-50 MPa, and whether the next stage of cold-hot circulation is carried out or not can be selected on the basis, so that the multistage variable-temperature cold-hot circulation improves the process flexibility and the production efficiency, and is favorable for saving the time cost and the economic cost.

Compared with the conventional treatment method, the beryllium material obtained by the optimized method has the advantages that the residual stress of the beryllium material is reduced to-50 MPa, and the dimensional change of the beryllium material after the beryllium material is placed at room temperature for one year is less than 0.002% (the residual stress can be reduced to below 0.001% or even can be reduced to 0.0008% after the beryllium material is optimized).

Detailed Description

In order to further enhance the understanding of the present invention, the following detailed description of the present invention is provided in connection with examples, and it should be noted that the scope of the present invention is not limited by the following examples.

Example 1:

firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 300 ℃, the temperature is kept for 24 hours, and 30MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 350 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-110 ℃, preserving heat for 60min, then heating to 250 ℃, and preserving heat for 60 min; the beryllium material is cooled to-20 ℃, kept for 60min, then heated to 150 ℃, kept for 600min, and finally cooled to the room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to-45 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0018 percent.

Example 2:

firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 310 ℃, the temperature is kept for 18h, and 40MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-190 ℃, preserving the heat for 80min, then heating to 300 ℃, and preserving the heat for 80 min; then, cooling the beryllium material to-110 ℃, preserving heat for 80min, then heating to 210 ℃, and preserving heat for 80 min; cooling the beryllium material to-10 ℃, preserving heat for 80min, then heating to 110 ℃, preserving heat for 80min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to-40 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0015 percent.

Example 3:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 320 ℃, preserving the heat for 4h, and applying tensile stress of 80 MPa. Then, carrying out multi-stage variable temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-185 ℃, preserving the heat for 70min, then heating to 340 ℃, and preserving the heat for 80 min; then, cooling the beryllium material to-95 ℃, preserving heat for 60-90 min, then heating to 240 ℃, and preserving heat for 100 min; cooling the beryllium material to-15 ℃, preserving heat for 110min, then heating to 140 ℃, preserving heat for 120min, and finally cooling to room temperature at the speed of 1 ℃/min. The residual stress of the beryllium material is reduced to-39 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0014 percent.

Example 4:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 330 ℃, preserving the heat for 20h, and applying tensile stress of 70 MPa. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 90min, then heating to 330 ℃, and preserving the heat for 90 min; then, cooling the beryllium material to-90 ℃, preserving heat for 60min, then heating to 200 ℃, and preserving heat for 60 min; cooling the beryllium material to-10 ℃, preserving heat for 120min, then heating to 120 ℃, preserving heat for 120min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to 31MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0012 percent.

Example 5:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 340 ℃, preserving the heat for 20h, and applying tensile stress of 70 MPa. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-180 ℃, preserving the heat for 100min, then heating to 350 ℃, and preserving the heat for 110 min; then, cooling the beryllium material to-110 ℃, preserving heat for 120min, then heating to 250 ℃, and preserving heat for 120 min; cooling the beryllium material to-20 ℃, preserving heat for 130min, then heating to 150 ℃, preserving heat for 140min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to 36MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0012 percent.

Example 6:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 360 ℃, preserving the heat for 6h, and applying tensile stress of 70 MPa. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 180min, then heating to 350 ℃, and preserving the heat for 180 min; then, cooling the beryllium material to-100 ℃, preserving heat for 120min, then heating to 240 ℃, and preserving heat for 120 min; cooling the beryllium material to-10 ℃, preserving heat for 60min, then heating to 130 ℃, preserving heat for 60min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to-32 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0013 percent.

Example 7:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 380 ℃, preserving the heat for 16h, and applying tensile stress of 60 MPa. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 180min, then heating to 300 ℃, and preserving the heat for 180 min; then, cooling the beryllium material to-90 ℃, preserving heat for 180min, then heating to 240 ℃, and preserving heat for 180 min; cooling the beryllium material to-10 ℃, preserving heat for 180min, then heating to 130 ℃, preserving heat for 180min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to 36MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0016 percent. The residual stress of the beryllium material is reduced to 43MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0015 percent.

Example 8:

firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 380 ℃, preserving the heat for 6h, and applying tensile stress of 80 MPa. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-190 ℃, preserving the heat for 90min, then heating to 350 ℃, and preserving the heat for 90 min; then, cooling the beryllium material to-110 ℃, preserving heat for 120min, then heating to 200 ℃, and preserving heat for 120 min; cooling the beryllium material to 0 ℃, preserving heat for 150min, then heating to 150 ℃, preserving heat for 150min, and finally cooling to room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is reduced to-38 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0017 percent.

Example 9:

firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 400 ℃, the temperature is kept for 4h, and tensile stress of 80MPa is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-180 ℃, preserving the heat for 180min, then heating to 300 ℃, and preserving the heat for 180 min; then, cooling the beryllium material to-90 ℃, preserving heat for 180min, then heating to 200 ℃, and preserving heat for 180 min; cooling the beryllium material to 0 ℃, preserving heat for 180min, then heating to 100 ℃, preserving heat for 180min, and finally cooling to room temperature at the speed of 3 ℃/min. The residual stress of the beryllium material is reduced to-46 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0019 percent.

Example 10:

firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 350 ℃, the temperature is kept for 12h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 320 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-100 ℃, preserving heat for 60min, then heating to 220 ℃, and preserving heat for 60 min; the beryllium material is cooled to 0 ℃, and is kept for 60min, then is heated to 120 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is reduced to 20MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0008 percent.

Comparative example 1: verification of the effectiveness of the stress aging treatment in comparison with example 10

Directly carrying out multi-stage variable-temperature cold-hot circulating stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 320 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-100 ℃, preserving heat for 60min, then heating to 220 ℃, and preserving heat for 60 min; the beryllium material is cooled to 0 ℃, and is kept for 60min, then is heated to 120 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is-210 MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0612 percent.

Example 11: validation of stress aging parameter optimization in comparison to example 10

Firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 500 ℃, the temperature is kept for 12h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 320 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-100 ℃, preserving heat for 60min, then heating to 220 ℃, and preserving heat for 60 min; the beryllium material is cooled to 0 ℃, and is kept for 60min, then is heated to 120 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is 65MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0028 percent.

Example 12: validation of stress aging parameter optimization in comparison to example 10

Firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 350 ℃, the temperature is kept for 30h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 320 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-100 ℃, preserving heat for 60min, then heating to 220 ℃, and preserving heat for 60 min; the beryllium material is cooled to 0 ℃, and is kept for 60min, then is heated to 120 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is 85MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0029 percent.

Example 13: validation of stress aging parameter optimization in comparison to example 10

Firstly, carrying out stress aging treatment on the beryllium material, heating the beryllium material to 350 ℃, preserving the heat for 12h, and applying 100MPa tensile stress. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 60min, then heating to 320 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-100 ℃, preserving heat for 60min, then heating to 220 ℃, and preserving heat for 60 min; the beryllium material is cooled to 0 ℃, and is kept for 60min, then is heated to 120 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is 165MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0046 percent.

Comparative example 2: compared with the example 10, the effectiveness of the multi-stage temperature-changing cold-hot circulation stabilizing treatment is verified

And (3) carrying out stress aging treatment on the beryllium material, heating the beryllium material to 350 ℃, preserving the heat for 12h, and applying 50MPa of tensile stress. The residual stress of the beryllium material is 120MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0532%.

Example 14: compared with the example 10, the effectiveness of the optimization of the multi-stage temperature-changing cold-hot circulation stabilizing treatment parameters is verified

Firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 350 ℃, the temperature is kept for 12h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 20min, then heating to 320 ℃, and preserving the heat for 20 min; then, cooling the beryllium material to-100 ℃, preserving heat for 20min, then heating to 220 ℃, and preserving heat for 20 min; cooling the beryllium material to 0 ℃, preserving heat for 20min, then heating to 120 ℃, preserving heat for 20min, and finally cooling to room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is reduced to 60MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0031 percent.

Example 15: compared with the example 10, the effectiveness of the optimization of the multi-stage temperature-changing cold-hot circulation stabilizing treatment parameters is verified

Firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 350 ℃, the temperature is kept for 12h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-196 ℃, preserving the heat for 240min, then heating to 320 ℃, and preserving the heat for 240 min; then, cooling the beryllium material to-100 ℃, preserving heat for 240min, then heating to 220 ℃, and preserving heat for 240 min; the beryllium material is cooled to 0 ℃, kept for 240min, then heated to 120 ℃, kept for 240min, and finally cooled to room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is reduced to 66MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0033 percent.

Comparative example 3: compared with the example 10, the effectiveness of the multi-stage temperature-changing cold-hot circulation stabilizing treatment is verified

Firstly, beryllium materials are subjected to stress aging treatment, the beryllium materials are heated to 350 ℃, the temperature is kept for 12h, and 50MPa tensile stress is applied. Then, carrying out multi-stage variable-temperature cold-hot circulation stabilization treatment on the beryllium material, cooling the beryllium material to-150 ℃, preserving the heat for 60min, then heating to 400 ℃, and preserving the heat for 60 min; then, cooling the beryllium material to-50 ℃, preserving heat for 60min, then heating to 300 ℃, and preserving heat for 60 min; the beryllium material is cooled to 50 ℃, and is kept for 60min, then is heated to 200 ℃, and is kept for 60min, and finally is cooled to the room temperature at the speed of 2 ℃/min. The residual stress of the beryllium material is reduced to 70MPa, and the dimensional change of the beryllium material after being placed at room temperature for one year is 0.0029 percent.