阅读说明：本技术 一种快速确定金属材料再结晶温度的装置和方法 (Device and method for rapidly determining recrystallization temperature of metal material ) 是由 张志豪 付华栋 谢建新 贠培文 周文健 于 2020-03-24 设计创作，主要内容包括：本发明属于金属材料加工与热处理技术领域,涉及一种金属材料再结晶温度的快速准确测试装置与方法。装置由加载机构、气氛保护加热炉、样品台和数据采集计算机组成。测试方法是通过采集三点弯曲试样在连续升温过程中的载荷-温度变化,进而确定金属材料的再结晶温度。本发明只需要一块试样,通过1～2h就能够完成以前长达1～2天、大量试样的研究工作,具有制样数量少,设备操作方便,确定再结晶温度快捷,运行成本低廉等优点；采用载荷-温度曲线自动实时获取,减少了硬度测试法、金相测试法等需要人为测试,大大降低了误差和人为干扰,准确度高。(The invention belongs to the technical field of metal material processing and heat treatment, and relates to a device and a method for quickly and accurately testing the recrystallization temperature of a metal material. The device consists of a loading mechanism, an atmosphere protection heating furnace, a sample stage and a data acquisition computer. The testing method is characterized in that the recrystallization temperature of the metal material is determined by collecting the load-temperature change of the three-point bending sample in the continuous temperature rise process. According to the invention, a large amount of samples can be studied for 1-2 days in the past only by using one sample for 1-2 hours, and the method has the advantages of small sample preparation amount, convenience in equipment operation, rapidness in determining the recrystallization temperature, low operation cost and the like; the load-temperature curve is automatically obtained in real time, manual tests such as a hardness test method and a metallographic test method are reduced, errors and manual interference are greatly reduced, and the accuracy is high.)

1. A device for rapidly determining the recrystallization temperature of a metal material is characterized by comprising a loading mechanism, an atmosphere protection heating furnace, a sample table (12) and a data acquisition computer (10); the loading mechanism consists of a pressure adjusting device (1), a positioning rod (2), a connecting threaded disc (3), a pressure sensor (4), a connecting threaded sleeve (5), a tightening nut (6), a quartz glass pressure rod (7) and a support frame (14), and the atmosphere protection heating furnace consists of an argon pipe (8), a thermocouple (9) and a heating furnace body (13); the pressure adjusting device (1) is arranged on a support frame (14), the bottom of the pressure adjusting device is connected with a pressure sensor (4) through a connecting threaded disc (3), the connecting threaded disc (3) is limited by a positioning rod (2) to ensure vertical linear motion, the pressure sensor (4) is connected with a quartz glass pressure rod (7) through a connecting threaded sleeve (5) and is fixed by a tightening nut (6), a sample (11) to be measured is arranged on a U-shaped sample table (12), the quartz glass pressure rod (7) penetrates through a heating furnace body (13) and applies load to the sample (11) to be measured, and an argon gas pipe (8) and a thermocouple (9) penetrate through the heating furnace body (13) and extend into the furnace body; and the data acquisition computer (10) is connected with the thermocouple (9) and the pressure sensor (4) and acquires temperature and pressure data in real time.

2. A method for measuring a recrystallization temperature using the apparatus according to claim 1, wherein the recrystallization temperature of the metal material is determined by collecting a load-temperature change of the three-point bent test piece during continuous temperature rise, and the measuring step is:

(1) placing a sheet sample to be tested on a U-shaped sample table, and applying a fixed load to the sample to be tested through a loading mechanism;

(2) introducing argon or nitrogen from an argon pipe;

(3) continuously heating by an atmosphere protection heating furnace, and selecting a heating rate according to needs;

(4) collecting and recording the changes of temperature and load in the continuous heating process through a computer, and stopping the experiment when the load is basically constant;

(5) and determining the recrystallization starting temperature or the recrystallization finishing temperature of the sample according to the inflection point in the collected load-temperature curve.

3. The method of claim 2, wherein the atmosphere protection heating furnace employs a resistance heating method, the maximum temperatures are 600 ℃, 1000 ℃ and 1500 ℃, and are used for the metal materials of the low temperature, the medium temperature and the high temperature recrystallization temperature, respectively; the heating rate is adjustable within the range of 0.01 ℃/s-0.5 ℃/s, and argon and nitrogen can be filled to form protective atmosphere; the loading mechanism is used for applying pressure of 0-200N to the test sample.

The technical field is as follows:

the invention belongs to the technical field of metal material processing and heat treatment, and relates to a method and a device for quickly determining the recrystallization temperature of a metal material.

Background art:

after the metal material is subjected to cold machining and warm machining plastic deformation, not only the internal organization structure and various properties are obviously changed, but also the metal material is in a thermodynamically unstable high free energy state due to the increase of defects such as vacancies, distortion, dislocation and the like. After the plastically deformed metal material is heated to a certain temperature, new grains without distortion are generated in the original deformed structure again, and the performance is obviously changed and is restored to the state before deformation, and the process is called recrystallization [ Hu 36179;, Xiang, Chua 29667, Yonghua. material science foundation, 3 edition [ M ]. Shanghai traffic university Press, 2010 ].

The recrystallization characteristics determine the hot working process (stress relief annealing process, aging annealing process and the like), the final performance (fine grain strengthening, recrystallization texture and the like) and the high-temperature service limit (single crystal blade recrystallization failure and the like) of the metal material; meanwhile, the metal recrystallization theory is one of the most basic scientific problems of material science, and the determination of the recrystallization characteristics of the metal material has important theoretical significance and application value.

The most critical parameter for recrystallization of metallic materials is the recrystallization temperature. The minimum temperature at which recrystallization of a metal subjected to large cold deformation (plastic deformation of 70% or more) can be completed within 1 hour of holding time is defined as the recrystallization temperature. At present, the methods for testing the recrystallization temperature of metal materials mainly comprise a metallographic microstructure analysis method, a hardness test method, a resistance test method, an X-ray diffraction method, a thermal analysis method and the like, and various methods are applied in different fields, but have the following problems: 1) the metallographic structure analysis method and the hardness test method are time-consuming, labor-consuming, low in efficiency and high in cost, and the recrystallization initial temperature of the metallographic structure analysis method is difficult to clearly define; 2) the resistance testing method has lower testing precision, and the recrystallization initial temperature is difficult to accurately test; 3) the X-ray diffraction method has long analysis and test time, low efficiency, special equipment and non-visual result; 4) the thermal analysis technology has the defects of expensive equipment, inconvenient operation, small size of a required test sample and difficulty in reflecting the overall characteristics of the material [ Lemneli, Liu Zheng, Wang Zhi, and the like ] the detection method for the recrystallization of the single crystal high-temperature alloy [ P ] the invention patent of China, the application number is 201710027990.1, and the application time is 2017-06-20; wangchuan, Kangyonglin, Marshalai, et al, ultra-low carbon aluminum killed steel cold-rolled sheet recrystallization temperature and performance research [ J ] hot working process, 2011,40(6): 36-39; determination of cold-rolled sheet annealing process for hot-dip galvanized steel sheet [ J ] physicochemical examination (physical itemization), 2009,45(10):595-598 ].

In contrast, the hardness test method is one of the more effective methods for determining the recrystallization temperature of an annealed metal sample by measuring the change in the hardness value of the annealed metal sample with the annealing temperature or the annealing time. For example, Sunzhua et al invented a new method for testing the recrystallization temperature of a cold-rolled strip steel sample by using a variable-temperature durometer device, which can quickly complete hardness value tests of different temperature points and determine the recrystallization temperature [ Sunzhua, Zhang Yunfei, Liu Bian, etc.. A rapid detection method for the recrystallization temperature of cold-rolled strip steel [ J ]. the invention patent of China, application No. 201610425022.1, application time 2016-11-09 ]. Von rock Qing et al invented a method for measuring the recrystallization temperature of steel for stamping, which measures the recrystallization temperature of cold-rolled deep-drawing steel of different compositions by using a laboratory small heat treatment furnace to simulate the hood-type production temperature rise rate, and determines the recrystallization temperature according to the hardness value change of air-cooled cold-rolled sheets discharged from the furnace at different temperatures [ Von rock Qing, Zhangxiao, Kangling ] quick detection method of recrystallization temperature of cold-rolled strip steel [ J ]. Chinese invention patent, application No. 201210185480.4, application time: 2012.06.01 ]. However, the hardness testing method needs to test the hardness of samples at multiple temperature points, and still has the disadvantages of large sample preparation quantity, long operation time, high operation cost, or the need of expensive equipment such as a variable temperature hardness tester, and the like.

Particularly for age-strengthened metal materials, the alloy is subjected to age precipitation hardening while recrystallization occurs, and the hardness of the alloy comprises the effects of recrystallization softening and precipitation hardening of the alloy, so that the recrystallization temperature of the tested alloy is inaccurate, and the like. Therefore, the recrystallization temperature test of the aging precipitation strengthening type metal material is a difficult problem troubling researchers for a long time, and a proper solution is not found yet.

The invention aims at the characteristics that the time required by precipitation strengthening of the metal material is long (generally more than 1 h) [ L ei Q, L i S, Zhu J, et. Micromicrotructural evolution, phase transition, and physics properties of high strain Cu-Ni-Si-Al alloy [ J ]. Materials characteristics, 2019,147: 315-.

The invention content is as follows:

the invention aims to provide a device and a method for quickly and accurately testing the recrystallization temperature of a metal material.

The invention provides a method for determining the recrystallization temperature of a metal material according to a load-temperature curve of a three-point bending sample in a continuous temperature rise process, and develops a device for quickly determining the recrystallization temperature of the metal material, wherein the technology has the advantages of quickness, time saving, energy saving, accuracy, low cost and the like; in particular, the difficult problem that the recrystallization temperature of the precipitation strengthening type metal material is difficult to accurately measure by the existing method can be better solved by utilizing the characteristics of long time required by precipitation strengthening and short time required by recrystallization softening of the metal material,

the device for rapidly determining the recrystallization temperature of the metal material, disclosed by the invention, is shown in the attached figure 1 and mainly comprises a loading mechanism, an atmosphere protection heating furnace, a sample table and a data acquisition computer. The loading mechanism consists of a pressure adjusting device (1), a positioning rod (2), a connecting threaded disc (3), a pressure sensor (4), a connecting threaded sleeve (5), a tightening nut (6), a quartz glass pressure rod (7) and a support frame (14), and the atmosphere protection heating furnace consists of an argon pipe (8), a thermocouple (9) and a heating furnace body (13). Pressure adjusting device (1) is arranged on support frame (14), its bottom is connected with pressure sensor (4) through connecting thread dish (3), connecting thread dish (3) are spacing to ensure straight line action from top to bottom through locating lever (2), pressure sensor (4) are connected and are fixed with tightening nut (6) through connecting thread cover (5) and quartz glass depression bar (7), on U-shaped sample platform (12) were arranged in to sample (11) that awaits measuring, quartz glass depression bar (7) pass heating furnace body (13), and exert load to sample (11) that awaits measuring, argon gas pipe (8) and thermocouple (9) pass heating furnace body (13) and stretch into the furnace body inside. And the data acquisition computer (10) is connected with the thermocouple (9) and the pressure sensor (4) and acquires and records temperature and pressure data in real time.

A method for measuring the recrystallization temperature by adopting the device is characterized in that the recrystallization temperature of the metal material is determined by collecting the load-temperature change of a three-point bending sample in the continuous temperature rise process, and the test steps are as follows:

(1) placing a sheet sample to be tested on a U-shaped sample table, and applying a fixed load to the sample to be tested through a loading mechanism;

(2) introducing argon from an argon pipe; nitrogen may be introduced according to the specific material of the test sample.

(3) Continuously heating by an atmosphere protection heating furnace, and selecting a heating rate according to needs;

(4) the temperature and load changes during continuous heating were collected and recorded by a computer and the experiment was stopped when the load was substantially constant.

The atmosphere protection heating furnace is used for heating a sample to be tested, adopts a resistance heating mode, has the highest temperatures of 600 ℃, 1000 ℃ and 1500 ℃, is respectively used for metal materials with low temperature, medium temperature and high temperature recrystallization temperature, has the heating rate adjustable within the range of 0.01 ℃/s-0.5 ℃/s, and can be filled with argon, nitrogen and the like to form a protective atmosphere. The loading mechanism is mainly used for applying pressure of 0-200N to a test sample. The measured data of the pressure sensor and the thermocouple are automatically collected and recorded by a computer.

The steps for testing the recrystallization temperature of the metal material comprise: placing a sheet sample to be tested on a U-shaped sample table, applying a fixed load to the sample to be tested through a loading mechanism, and then introducing argon through an argon pipe (nitrogen can also be introduced according to the specific material of the sample to be tested); continuously heating through a heating furnace body, and selecting a heating rate according to requirements; the change of temperature and load in the continuous heating process is collected and recorded by a data collecting computer, and the experiment is stopped when the load is basically constant; finally, the recrystallization start temperature and the recrystallization finish temperature of the sample were determined from two inflection points in the collected load-temperature curve (as shown in FIG. 2).

The invention has the advantages that:

(1) according to the invention, a large amount of samples can be studied for 1-2 days in the past only by using one sample for 1-2 hours, and the method has the advantages of small sample preparation amount, convenience in equipment operation, rapidness in determining the recrystallization temperature, low operation cost and the like;

(2) the invention adopts the load-temperature curve to automatically obtain in real time, reduces the need of manual tests such as a hardness test method, a metallographic test method and the like, greatly reduces errors and human interference and has high accuracy.

Drawings

FIG. 1 is a schematic view of an apparatus for rapidly determining a recrystallization temperature of a metallic material according to the present invention,

the reference numbers are: the device comprises a pressure adjusting device (1), a positioning rod (2), a connecting threaded disc (3), a pressure sensor (4), a connecting threaded sleeve (5), a tightening nut (6), a quartz glass pressure rod (7), an argon pipe (8), a thermocouple (9), a data acquisition computer (10), a sample (11), a sample table (12), a heating furnace body (13) and a support frame (14).

Fig. 2 is a typical load-temperature curve measured by the present invention.

The specific implementation mode is as follows: