阅读说明：本技术 一种采用立式管式炉进行钛合金β转变温度测量的方法 (Method for measuring titanium alloy beta transition temperature by adopting vertical tube furnace ) 是由 高慧贤 李芹芹 朱静 刘伟 张理童 刘京州 李建峰 刘向宏 冯勇 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种采用立式管式炉进行钛合金β转变温度测量的方法,具体包括如下步骤：步骤1,在样品腔中布置热偶；步骤2,按照检测标准和钛合金的相变点温度,设定检测温度；步骤3,当热偶检测到样品腔内的温度达到步骤2设定的检测温度时,开始装样,并对样品进行热处理然后保温；步骤4,样品保温结束后,从上端间断金属丝,样品在下端重物块的牵引下顺利出炉,落入样品腔正下方的水槽中；步骤5,按检测标准对经步骤4处理后的样品进行制样腐蚀,并判断得到的相变点。本发明降低了样品在热处理过程中超出均匀区范围的风险,提升了实验的成功率。(The invention discloses a method for measuring the beta transition temperature of titanium alloy by adopting a vertical tube furnace, which comprises the following steps: step 1, arranging a thermocouple in a sample cavity; step 2, setting a detection temperature according to the detection standard and the temperature of the phase transformation point of the titanium alloy; step 3, when the thermocouple detects that the temperature in the sample cavity reaches the detection temperature set in the step 2, starting sample loading, carrying out heat treatment on the sample and then carrying out heat preservation; step 4, after the sample is insulated, cutting off the metal wire from the upper end, and smoothly discharging the sample out of the furnace under the traction of the heavy object block at the lower end to fall into a water tank right below the sample cavity; and 5, carrying out sample preparation corrosion on the sample treated in the step 4 according to a detection standard, and judging the obtained phase change point. The invention reduces the risk that the sample exceeds the range of the uniform area in the heat treatment process and improves the success rate of the experiment.)

1. A method for measuring the beta transition temperature of titanium alloy by adopting a vertical tube furnace is characterized by comprising the following steps: the method specifically comprises the following steps:

step 1, arranging a thermocouple in a sample cavity;

step 2, setting a detection temperature according to the detection standard and the temperature of the phase transformation point of the titanium alloy;

step 3, when the thermocouple detects that the temperature in the sample cavity reaches the detection temperature set in the step 2, starting sample loading, carrying out heat treatment on the sample and then carrying out heat preservation;

step 4, after the sample is insulated, cutting off the metal wire from the upper end, and smoothly discharging the sample out of the furnace under the traction of the heavy object block at the lower end to fall into a water tank right below the sample cavity;

and 5, carrying out sample preparation corrosion on the sample treated in the step 4 according to a detection standard, and judging the obtained phase change point.

2. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 1, wherein the method comprises the following steps: and the sample cavity in the step 1 is a high-temperature-resistant quartz tube with a turned-over edge at the upper part and a wall thickness of 1-3 mm.

3. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 2, wherein the method comprises the following steps: the number of the thermocouples is three, and the three thermocouples are inserted into the quartz tube and distributed in the sample cavity.

4. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 3, wherein the method comprises the following steps: the three thermocouples can be respectively inserted into one quartz tube and can also be simultaneously inserted into one quartz tube.

5. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 4, wherein the method comprises the following steps: the heights of the three thermocouples in the quartz tube are sequentially reduced, and the height difference between the thermocouple with the highest height and the thermocouple with the lowest height is 150-200 mm.

6. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 3, wherein the method comprises the following steps: three thermocouples can be further arranged in the sample cavity, and the thermocouples are located in the middle of the sample cavity, wherein the distance from the thermocouples to the top of the sample cavity is 120-180 mm.

7. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 5, wherein the method comprises the following steps: and 3, stringing the titanium alloy sample on a metal wire, determining the furnace entering depth, marking the position on the metal wire, hanging a heavy object block at the lower end of the metal wire, then loading the titanium alloy sample into the sample cavity, ensuring that the heavy object is positioned outside the sample cavity, and fixing the upper end of the metal wire.

8. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 7, wherein the method comprises the following steps: and the heat treatment heat preservation time in the step 3 is 30-40 minutes.

9. The method for measuring the beta transus temperature of the titanium alloy by using the vertical tube furnace according to claim 7, wherein the method comprises the following steps: in the step 4, the time from the sample cavity to the water tank for the titanium alloy sample to fall into the water tank is not more than 3 s.

Technical Field

The invention belongs to the technical field of titanium alloy material performance measurement, and relates to a method for measuring the beta transition temperature of a titanium alloy by adopting a vertical tube furnace.

Background

The beta transus temperature (hereinafter referred to as "transformation point") of a titanium alloy is defined as the lowest temperature at which the titanium alloy is completely transformed into a beta structure during heating. The measurement of the phase transformation point requires that the heat treatment furnace is a type I furnace, and the furnace temperature uniformity is not more than +/-3 ℃. After investigation, most physicochemical laboratories with the detection capability adopt a box-type furnace or a horizontal tubular furnace and other special phase change point furnaces. Most laboratories without dedicated ovens do not perform this test, and most of these laboratories have a number of endurance or high temperature tensile universal machines each with a vertical tube oven.

The vertical tube furnace with a general mechanical high-temperature testing machine (such as a high-temperature tensile testing machine, a endurance testing machine and the like) can also meet the requirement of +/-3 ℃, the hearth is large, but the radial uniform area of the hearth is small, generally phi 20-30 mm, and an obvious temperature gradient exists from the center to the furnace wall; in addition, the upper furnace plug and the lower furnace plug are provided with transition steps, when the transition steps are directly used for heat treatment of a phase change point, a sample can often fall on the steps during discharging water quenching, so that the sample can not be discharged from the furnace within 5 seconds, and the test fails.

Disclosure of Invention

The invention aims to provide a method for measuring the beta transition temperature of titanium alloy by adopting a vertical tube furnace, which reduces the risk that a sample exceeds the range of a uniform area in the heat treatment process and improves the success rate of experiments.

The invention adopts the technical scheme that a method for measuring the beta transition temperature of titanium alloy by adopting a vertical tube furnace specifically comprises the following steps:

step 1, arranging a thermocouple in a sample cavity;

step 2, setting a detection temperature according to the detection standard and the temperature of the phase transformation point of the titanium alloy;

step 3, when the thermocouple detects that the temperature in the sample cavity reaches the detection temperature set in the step 2, starting sample loading, carrying out heat treatment on the sample and then carrying out heat preservation;

step 4, after the sample is insulated, cutting off the metal wire from the upper end, and smoothly discharging the sample out of the furnace under the traction of the heavy object block at the lower end to fall into a water tank right below the sample cavity;

and 5, carrying out sample preparation corrosion on the sample treated in the step 4 according to a detection standard, and judging the obtained phase change point.

The present invention is also characterized in that,

the sample cavity in the step 1 is a high-temperature-resistant quartz tube with a turned-over edge at the upper part and a wall thickness of 1-3 mm.

The number of the thermocouples is three, and the three thermocouples are inserted into the quartz tube and distributed in the sample cavity.

The three thermocouples can be respectively inserted into one quartz tube and can also be simultaneously inserted into one quartz tube.

The heights of the three thermocouples in the quartz tube are sequentially reduced, and the height difference between the thermocouple with the highest height and the thermocouple with the lowest height is 150-200 mm.

Three thermocouples can be arranged in the sample cavity, and the thermocouples are positioned in the middle of the sample cavity with the height of 120-180 mm away from the top of the sample cavity.

And 3, stringing the titanium alloy sample on a metal wire, determining the furnace entering depth, marking the position on the metal wire, hanging a heavy object block at the lower end of the metal wire, then loading the titanium alloy sample into the sample cavity, ensuring that the heavy object is positioned outside the sample cavity, and fixing the upper end of the metal wire.

And (3) the heat treatment heat preservation time in the step 3 is 30-40 minutes.

In the step 4, the time from the sample outlet cavity to the water tank of the titanium alloy sample does not exceed 3 s.

The vertical tube furnace has the beneficial effects that the sample cavity suitable for discharging and charging phase change points is arranged in the vertical tube furnace, and the length of the sample cavity in the vertical height of the center is about 100-200 mm through reasonable thermocouple layout, so that the temperature requirement can be met; in addition, different from the discharging mode of a box-type furnace and a horizontal tube furnace, the sample is made to freely fall when discharged from the furnace by utilizing gravity and quickly enter water to finish water quenching, and the whole process can be controlled within about 3 seconds (the measurement standard requirement is less than 5 seconds).

Drawings

FIG. 1 is a schematic structural diagram of a sample chamber in a method for measuring the beta transus temperature of a titanium alloy by using a vertical tube furnace according to the present invention;

FIG. 2 is a top view of a quartz tube mounted in a sample chamber in a method of measuring the beta transus temperature of a titanium alloy using a vertical tube furnace according to the present invention;

FIG. 3 is a schematic structural view of a thermocouple installed in a sample chamber in a method for measuring a beta transus temperature of a titanium alloy using a vertical tube furnace according to the present invention;

FIG. 4 is a schematic view showing a state where a sample is placed in a sample chamber in a method for measuring a beta transus temperature of a titanium alloy using a vertical tube furnace according to the present invention;

FIG. 5 is a high power plot near the beta transus temperature of a TC18 titanium alloy coupon measured using a method of the present invention for titanium alloy beta transus temperature measurement using a vertical tube furnace;

fig. 6 is a high magnification picture of the vicinity of the β transus temperature of a TC21 titanium alloy sample measured for the β transus temperature using a method of the present invention for measuring the β transus temperature of a titanium alloy using a vertical tube furnace.

In the figure, 1 is a sample chamber, 2 is a quartz tube, 3 is a thermocouple, 4 is a metal wire, 5 is a titanium alloy sample, and 6 is a heavy object block.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

The invention relates to a method for measuring the beta transition temperature of titanium alloy by adopting a vertical tube furnace, which comprises the following steps:

step 1, arranging a thermocouple in a sample cavity;

the structure of the sample cavity 1 is shown in figure 1, the internal dimension of the sample cavity 1 is designed to be between 40mm and 70mm (according to the dimension of a vertical tube furnace of a mechanical high-temperature tester in each laboratory); the shape is consistent about in the sample chamber 1 so that the sample business turn over, and sample chamber 1 adopts the high temperature resistant quartz capsule that upper portion area turn-ups and wall thickness are 1 ~ 3 mm. The quartz tube conducts heat quickly and is insulating. The quartz tube has good thermal conductivity and light transmittance, and can quickly conduct heat to the inside; in addition, the quartz tube is used as a heat radiation screen, and a good temperature equalizing effect is achieved.

As shown in fig. 2 and 3, the number of the thermocouples 3 is three, and three thermocouples 3 are inserted into the quartz tube 2 and arranged in the sample chamber 1.

Three thermocouples 3 can be inserted into one quartz tube 2 respectively or simultaneously into one quartz tube 2.

The center of the sample cavity is provided with a thermocouple (A), and the other two thermocouples (B, C) are respectively and symmetrically arranged at two opposite sides of the thermocouple (A);

the heights of the three thermocouples in the quartz tube are sequentially reduced, the height difference between the thermocouple with the highest height and the thermocouple with the lowest height is 150-200 mm, so that the uniform area can be ensured to be at least within the range of 120-180 mm, the thermocouple layout is shown in figure 3, and the temperature uniformity and the vertical height range from the center to the cavity wall in the sample cavity can be controlled within +/-2 ℃ through the temperature equalizing effect of the sample cavity, so that the standard +/-3 ℃ requirement is better.

Three thermocouples can be arranged in the sample cavity, the thermocouples are positioned in the middle of the sample cavity with the height of 120-180 mm away from the top of the sample cavity, and the three thermocouples can be used for detecting the temperature uniformity from the center of the sample cavity to the furnace wall.

Step 2, setting a detection temperature according to the detection standard and the temperature of the phase transformation point of the titanium alloy;

step 3, when the thermocouple detects that the temperature in the sample cavity reaches the detection temperature set in the step 2, starting sample loading, carrying out heat treatment on the sample and then carrying out heat preservation;

the specific process of the step 3 is, referring to fig. 4, stringing a titanium alloy sample 5 on a metal wire 4, determining the furnace entering depth, marking the position on the metal wire 4, hanging a weight block 6 on the lower end of the metal wire 4, then loading the titanium alloy sample 5 into the sample cavity 1, ensuring that the weight block 6 is positioned outside the sample cavity 1, and fixing the upper end of the metal wire 4. The number of samples on the wire 4 does not exceed 5.

The heat treatment and heat preservation time is 30-40 minutes.

Step 4, after the sample is insulated, cutting off the metal wire from the upper end, and smoothly discharging the sample out of the furnace under the traction of the heavy object block at the lower end to fall into a water tank right below the sample cavity;

the time from the sample cavity to the water tank for the titanium alloy sample to fall into the water tank is not more than 3 s.

And 5, carrying out sample preparation corrosion on the sample treated in the step 4 according to a detection standard, and judging the obtained phase change point.