A sample rapid cooling device for a creep endurance testing machine

Abstract

The present invention provides a sample rapid cooling device for a creep endurance testing machine, which is applied to the long-term creep endurance performance test of metal materials and the microstructure analysis during the life assessment process. The present invention adopts a liquid nitrogen cooling environment box bracket and a track moving positioning design, and when the creep endurance test reaches the specified time, the liquid nitrogen cooling environment box can be quickly moved to the position of the high-temperature heating furnace of the creep endurance testing machine and docked with its opening. After accurate positioning, the switching between the liquid nitrogen cooling environment box and the high-temperature heating furnace is quickly completed, and the liquid nitrogen cooling system of the environment box is used to achieve rapid cooling of the high-temperature creep endurance test sample. The real-time microstructure characteristics of the material are maintained by rapid cooling during the test, which solves the problem of online real-time analysis of the microstructure of the high-temperature creep endurance test sample. The device method is simple and easy to implement, and is easy to implement in the rapid cooling treatment of high-temperature samples in creep endurance testing machines and other fields, and can be industrialized.

Description

Technical Field

[0001] The present invention belongs to the technical field of long-term continuous creep endurance performance testing and organizational structure analysis, and specifically relates to a sample rapid cooling device for a creep endurance testing machine. Background Art

[0002] In actual operation, key components of thermal power units, such as high-temperature boiler tubes, high-temperature headers, and high-temperature pipelines, are in high-temperature and high-pressure environments, and creep damage is their main failure form. Research on creep damage mechanisms and damage laws of materials is one of the basic high-temperature information of materials that must be referenced in material research and development, component design, life prediction, and reliability assessment.

[0003] Creep damage of materials refers to the irreversible permanent plastic deformation of components caused by creep, and the performance degradation of component materials caused by microstructure aging. In addition to stress and temperature conditions, creep damage of materials is also related to time, which is a long-term cumulative destructive process. The engineering community defines the stress corresponding to the creep rupture of a material at a certain temperature for 100,000 hours as the creep rupture strength or endurance strength limit of the material at that temperature, and stipulates that it is the basis for the design of high-temperature structural materials.

[0004] As early as the 1930s, it was impossible to conduct creep rupture tests of materials at a certain temperature for 100,000 hours continuously, and its endurance strength limit was difficult to obtain through actual test measurements. Therefore, researchers have proposed various methods for extrapolating the endurance strength of high-temperature structural materials. With the continuous development of science and technology, a large amount of creep rupture data of 100,000 or even 200,000 hours has emerged. Scientific research, especially engineering and technical personnel, have continuously tested, analyzed, summarized and optimized the extrapolation methods, forming the existing "isothermal extrapolation model", "time-temperature parameter model", "Robinson life consumption method" based on endurance strength, "θ prediction method" based on creep deformation, "creep curve extrapolation model" and "creep damage cracking and crack extension model" based on fracture mechanics. The system of material long-term creep life extrapolation methods has been formed.

[0005] In the long-term creep life extrapolation method of materials, the life extrapolation model based on endurance strength and creep deformation requires a large amount of creep performance data support. In addition, the organizational structure aging phenomenon of materials used in thermal power units after service is very serious, and the aging conditions of different components and different materials vary greatly, which will cause uncertainty in the material creep life extrapolation method. Therefore, while conducting long-term creep performance tests on materials, it is also very important to analyze in detail the creep damage mechanism of the material and the organizational structure aging law during the creep process, and to correct the creep life extrapolation model accordingly.

[0006] At present, the structural analysis of materials during creep endurance is mostly carried out by offline analysis after the samples are cooled with the furnace after the test. The structural characteristics obtained are somewhat different from the information during the real-time operation of the material during high-temperature creep. Therefore, a rapid cooling system for test samples is designed in the existing creep endurance test equipment to form a new type of material long-term creep damage test equipment, obtain and accumulate accurate long-term creep structural data of key materials for thermal power units, reveal the creep damage mechanism and structural aging law of materials for thermal power units during long-term operation, and provide basic technical support for the high-reliability creep life assessment extrapolation method and engineering application of key high-temperature components / materials of thermal power units. It has important economic and social significance for the localization research and development of materials for thermal power units in my country, the design of high-temperature components of units and the safe operation of power stations. Summary of the invention

[0007] In order to solve the above problems, the present invention provides a sample rapid cooling device for a creep endurance tester, wherein the rapid cooling device adopts a liquid nitrogen cooling environment box bracket and a track moving positioning design, and when the creep endurance test reaches a specified time, the liquid nitrogen cooling environment box is moved to the position of the high temperature heating furnace of the creep endurance tester and docked with its opening, and after accurate positioning, the switching between the high temperature heating furnace and the liquid nitrogen cooling environment box is quickly completed, so as to realize the rapid cooling of the high temperature creep endurance test sample;

[0008] Furthermore, the rapid cooling equipment includes a high-temperature heating furnace bracket and a test host. The high-temperature heating furnace bracket adopts a four-column structure, the lower end of the column is connected to the test host, and the upper end of the column is equipped with two bracket linear slide rails; the lower bottom surface of the high-temperature heating furnace base is designed with a pulley that matches the bracket linear slide rail, and is placed on the bracket linear slide rail, so that the high-temperature heating furnace base can move freely on the bracket linear slide rail; the high-temperature heating furnace for the creep endurance tester is placed on the high-temperature heating furnace base;

[0009] Furthermore, the rapid cooling device also includes a mobile trolley and a liquid nitrogen cooling environmental box, the mobile trolley includes an environmental box base, casters, a liquid nitrogen tank mobile box and a linear slide rail for the mobile trolley, and a pulley for matching the linear slide rail for the mobile trolley is designed at the lower end of the environmental box base and is placed on the linear slide rail, which can be used to realize the free movement of the environmental box base on the linear slide rail of the mobile trolley;

[0010] Furthermore, the liquid nitrogen cooling environment box is placed on the environment box base of the mobile trolley; the upper end of the liquid nitrogen cooling environment box is designed with a liquid nitrogen gas inlet, and the liquid nitrogen gas inlet is connected to the upper end of a precision seamless steel pipe for conveying liquid nitrogen gas through a ferrule joint; the lower end of the precision seamless steel pipe is connected to a liquid nitrogen tank, and a pressure reducing valve and a ball valve switch are designed at the gas outlet end of the liquid nitrogen tank; the liquid nitrogen tank is placed in a liquid nitrogen tank mobile box of the mobile trolley;

[0011] Furthermore, the liquid nitrogen cooling environment box, the liquid nitrogen gas inlet, the precision seamless steel pipe, the pressure reducing valve, the ball valve switch, and the liquid nitrogen tank constitute a liquid nitrogen cooling system for the environment box;

[0012] Further, the rapid cooling by the rapid cooling device comprises the following steps:

[0013] 1): When the creep endurance test reaches the specified time, the mobile trolley moves the liquid nitrogen cooling environment box, liquid nitrogen tank, etc. to the testing machine, and uses the positioning device to dock and lock the linear slide rail of the mobile trolley with the linear slide rail of the high-temperature heating furnace bracket;

[0014] 2): Use the linear slide rail of the mobile trolley to move the liquid nitrogen cooling environment box, dock it with the high-temperature heating furnace, and fix the liquid nitrogen environment box and the high-temperature heating furnace together with positioning sleeves and pins;

[0015] 3): Open the liquid nitrogen environment box and the high temperature heating furnace to a fixed angle, quickly move the liquid nitrogen cooling environment box and the high temperature heating furnace, and turn on the liquid nitrogen cooling system of the environment box. When the liquid nitrogen cooling environment box moves to the original working position of the high temperature heating furnace, close the liquid nitrogen environment box and the high temperature heating furnace to achieve rapid cooling of the test sample;

[0016] Furthermore, the rapid cooling device is used for rapid cooling of high temperature test samples in creep endurance testing machines and other fields;

[0017] The beneficial effects of the present invention are as follows:

[0018] Through the precise positioning design of the liquid nitrogen cooling environment box, mobile trolley, guide rails, etc. and the reasonable configuration of the staff, when the creep endurance test reaches a specific time, the sample rapid cooling equipment can be used to switch between the liquid nitrogen cooling environment box and the high-temperature heating furnace within 5 seconds to complete the rapid cooling of the high-temperature creep test sample. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the general assembly diagram of the sample rapid cooling equipment for the creep endurance testing machine of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. On the contrary, the present invention encompasses any substitutions, modifications, equivalent methods and schemes made on the essence and scope of the present invention as defined by the claims. Further, in order to enable the public to have a better understanding of the present invention, some specific details are described in detail in the detailed description of the present invention below. For those skilled in the art, the present invention can be fully understood without the description of these details.

[0021] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but this is not intended to limit the present invention. The following is a preferred embodiment of the present invention:

[0022] like Figure 1 As shown, the present invention discloses a rapid cooling device for a sample used in a creep endurance tester, which is a high-temperature creep endurance tester heated by a resistance furnace. Its detailed design and structure are as follows:

[0023] 1): A high-temperature heating furnace bracket is designed on the creep endurance test host 1. The high-temperature heating furnace bracket adopts a four-column structure 4. The lower end of the column structure 4 is connected to the test host 1, and two bracket linear slide rails 5 are arranged on the upper end of the column structure; the lower bottom surface of the high-temperature heating furnace base 6 is designed with a pulley 7 that cooperates with the bracket linear slide rail 5, and is placed on the bracket linear slide rail 5, so that the high-temperature heating furnace base 6 can move freely on the bracket linear slide rail 5; the high-temperature heating furnace 2 for the creep endurance test machine is placed on the high-temperature heating furnace base 6.

[0024] 2): The mobile trolley is composed of an environmental chamber base 8, casters 9, a liquid nitrogen tank mobile box 10, a mobile trolley linear slide 11, etc. A pulley 12 is designed at the lower end of the environmental chamber base 8 to match the mobile trolley linear slide 11 and is placed on the mobile trolley linear slide 11, so that the environmental chamber base 8 can move freely on the mobile trolley linear slide 11.

[0025] 3): The liquid nitrogen cooling environment box 3 and the high temperature heating furnace 2 for the testing machine adopt the same appearance and structural design, and are placed on the environmental box base 8 of the mobile trolley; the upper end of the liquid nitrogen cooling environment box 3 is designed with a liquid nitrogen gas inlet 13, and the gas inlet 13 is connected to the upper end of a precision seamless steel pipe 14 for conveying liquid nitrogen gas through a ferrule joint; the lower end of the precision seamless steel pipe 14 is connected to the liquid nitrogen tank, and a pressure reducing valve and a ball valve switch are designed at the gas outlet of the liquid nitrogen tank; the liquid nitrogen tank is placed in the liquid nitrogen tank mobile box 10 of the mobile trolley.

[0026] 4): Liquid nitrogen cooling environment box 3, liquid gas inlet 13, precision seamless steel pipe 14, pressure reducing valve, ball valve switch, liquid nitrogen tank constitute the liquid nitrogen cooling system of the environment box.

[0027] 5): When the creep endurance test reaches the specified time, the mobile trolley moves the liquid nitrogen cooling environment box 3, the liquid nitrogen tank, etc. to the test host 1, and uses the positioning device 15 to dock and lock the linear slide rail 11 of the mobile trolley with the linear slide rail 5 of the high-temperature heating furnace support. Use the linear slide rail 11 of the mobile trolley to move the liquid nitrogen cooling environment box 3, dock it with the high-temperature heating furnace 2, and use the positioning sleeve and pin 16 to fix the liquid nitrogen environment box 3 and the high-temperature heating furnace 2 together.

[0028] 5): Open the liquid nitrogen environment box 3 and the high-temperature heating furnace 2 to a fixed angle, quickly move the liquid nitrogen cooling environment box 3 and the high-temperature heating furnace 2, and start the liquid nitrogen cooling system of the environment box. When the liquid nitrogen cooling environment box moves to the original working position of the high-temperature heating furnace 2, close the liquid nitrogen environment box 3 and the high-temperature heating furnace 2 to achieve rapid cooling of the test sample.

[0029] Through the precise positioning design of the liquid nitrogen cooling environment box, mobile trolley, guide rails, etc. and the reasonable configuration of the staff, when the creep endurance test reaches a specific time, the sample rapid cooling equipment can be used to switch between the liquid nitrogen cooling environment box and the high-temperature heating furnace within 5 seconds to complete the rapid cooling of the high-temperature creep test sample.

[0030] Compared with the existing testing equipment, the feature of the present invention is that when the creep endurance test reaches the specified time, the liquid nitrogen environment box and the high-temperature heating furnace can be quickly switched to achieve rapid cooling of the high-temperature creep test sample.

[0031] Embodiment 1:

[0032] In order to obtain the evolution law of the microstructure of P92 heat-resistant steel during the 650℃ creep endurance process, it is necessary to carry out the 650℃-10h / 60h / 120h / 180h / 300h creep endurance interruption test of the material. At the beginning of the test, the design and operation of the high-temperature creep endurance test are normally carried out using a high-temperature creep endurance test machine. When the test reaches the target test time: 10h / 60h / 120h / 180h / 300h, the mobile trolley is used to complete the docking and switching between the liquid nitrogen cooling environment box and the high-temperature heating furnace of the test machine in the present invention. At the same time, the liquid nitrogen cooling system of the liquid nitrogen cooling environment box is turned on to achieve rapid cooling of the P92 heat-resistant steel 650℃ creep endurance test sample, maintain its real-time microstructure characteristics, and complete the microstructure evolution analysis of the material during the 650℃ creep endurance process.

[0033] The embodiment described above is only one of the more preferred specific implementations of the present invention. Common changes and substitutions made by those skilled in the art within the scope of the technical solution of the present invention should be included in the protection scope of the present invention.

Claims

1. A sample rapid cooling device for a creep endurance testing machine, characterized in that: The rapid cooling equipment adopts a liquid nitrogen cooling environment box bracket and a track moving positioning design. When the creep endurance test reaches a specified time, the liquid nitrogen cooling environment box is moved to the position of the high temperature heating furnace of the creep endurance test machine and docked with its opening. After accurate positioning, the high temperature heating furnace and the liquid nitrogen cooling environment box are quickly switched, and the liquid nitrogen cooling system is used to achieve rapid cooling of the high temperature creep endurance test sample. The rapid cooling equipment comprises a high-temperature heating furnace support and a test host. The high-temperature heating furnace support adopts a four-column structure, the lower end of the column is connected to the test host, and the upper end of the column is provided with two support linear slide rails; the lower bottom surface of the high-temperature heating furnace base is designed with a pulley matching the support linear slide rail, and is placed on the support linear slide rail, so that the high-temperature heating furnace base can move freely on the support linear slide rail; the high-temperature heating furnace for the creep endurance test machine is placed on the high-temperature heating furnace base; The rapid cooling device also includes a mobile trolley and a liquid nitrogen cooling environmental box, the mobile trolley includes an environmental box base, casters, a liquid nitrogen tank mobile box and a linear slide rail for the mobile trolley, the lower end of the environmental box base is designed with a pulley that matches the linear slide rail of the mobile trolley and is placed on the linear slide rail, which can be used to realize the free movement of the environmental box base on the linear slide rail of the mobile trolley; The liquid nitrogen cooling environment box is placed on the environment box base of the mobile trolley; a liquid nitrogen gas inlet is designed at the upper end of the liquid nitrogen cooling environment box, and the liquid nitrogen gas inlet is connected to the upper end of a precision seamless steel pipe for conveying liquid nitrogen gas through a ferrule joint; the lower end of the precision seamless steel pipe is connected to a liquid nitrogen tank, and a pressure reducing valve and a ball valve switch are designed at the gas outlet end of the liquid nitrogen tank; the liquid nitrogen tank is placed in a liquid nitrogen tank mobile box of the mobile trolley; The liquid nitrogen cooling environment box, liquid gas inlet, precision seamless steel pipe, pressure reducing valve, ball valve switch, and liquid nitrogen tank constitute a liquid nitrogen cooling system for the environment box; The rapid cooling device can realize the switching between the liquid nitrogen cooling environment box and the high temperature heating furnace within 5 seconds, and complete the rapid cooling of the high temperature creep test sample.

2. The rapid cooling device according to claim 1, characterized in that: The rapid cooling of the creep endurance test sample by the rapid cooling device comprises the following steps: 1) When the creep endurance test reaches the specified time, the mobile trolley moves the liquid nitrogen cooling environment box, liquid nitrogen tank, etc. to the test host, and the positioning device is used to dock and lock the linear slide rail of the mobile trolley with the linear slide rail of the high-temperature heating furnace bracket; 2) Use the linear slide rail of the mobile trolley to move the liquid nitrogen cooling environment box, dock it with the high-temperature heating furnace, and fix the liquid nitrogen environment box and the high-temperature heating furnace together with positioning sleeves and pins; 3) Open the liquid nitrogen environment box and the high-temperature heating furnace to a fixed angle, quickly move the liquid nitrogen cooling environment box and the high-temperature heating furnace, and start the liquid nitrogen cooling system of the environment box. When the liquid nitrogen cooling environment box moves to the original working position of the high-temperature heating furnace, close the liquid nitrogen environment box and the high-temperature heating furnace to achieve rapid cooling of the test sample.

3. The rapid cooling device according to claim 2, characterized in that: The rapid cooling device is used for rapid cooling of high temperature test samples in creep endurance testing machines and other fields.

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