CN116337642A - Method for measuring elongation of high-temperature tensile sample - Google Patents
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Abstract
The invention relates to a method for measuring mechanical properties of a metal material in a high-temperature tensile test, in particular to a method for measuring elongation of a high-temperature tensile sample. Placing the sample into the solution, and descending the same distance d and mm each time; plotting the relation between the total volume V of the solution and the sample immersed in the solution and the sample falling distance d, if the point A corresponds to the sample falling distance d 1 Mm, point B corresponds to a sample falling distance d 2 Mm, then l=d 2 ‑d 1 The method comprises the steps of carrying out a first treatment on the surface of the Measuring the original length l of the sample 0 Mm, length of two samples joined into sample l 1 Mm, the deformation Δl mm of the high-temperature stretching is Δl=l 1 ‑l 0 The method comprises the steps of carrying out a first treatment on the surface of the The actual deformation part of the sampleOriginal length L of the branch 0 Is L 0 =l- Δl; the elongation lambda,%, is obtained according to the elongation calculation formula
The invention can effectively and accurately measure the elongation of the high-temperature tensile sample.
Description
Technical Field
The invention relates to a method for measuring mechanical properties of a metal material in a high-temperature tensile test, in particular to a method for measuring elongation of a high-temperature tensile sample.
Background
The thermodynamic simulation experiment machine is a physical property test instrument used in the field of material science, and the thermodynamic simulation experiment is an important means for researching metallurgical materials by utilizing a small sample and by means of the thermodynamic simulation experiment machine, and plays an important role in new product development and process optimization. The main function of the thermal simulation experiment machine is to reproduce the physical process of heating or heating and stressing of materials (especially steel materials) in the preparation or hot working process, study the change rule of the organization or performance of the materials, evaluate or predict the problems of the materials in the preparation or heating process, and provide theoretical guidance and technical basis for formulating reasonable processing technology and developing new materials.
In order to study the plasticity of a casting blank in the continuous casting process, a thermal simulation tester is generally adopted to heat a sample to a higher temperature range, keep the temperature in the high temperature range for a period of time, then reduce the temperature to a certain temperature, finally stretch the sample at a certain stretching rate at a high temperature until the sample is broken, and analyze the cross section area of the broken sample, thereby obtaining the reduction of area.
However, the mechanical property parameter reflecting plasticity is elongation after fracture in addition to reduction of area. For the measurement of elongation, it is common to focus on the measurement of elongation of room temperature tensile samples. Because the material has certain fluidity in a high-temperature state, and the temperature distribution of the sample has a certain gradient when the sample is heated by the thermal simulation tester, the whole sample does not participate in deformation when the sample is deformed in a stretching way, and the performance of the sample is more obvious on the resistance type thermal simulation tester. If the original length of the entire specimen is still used in calculating the elongation, a large error is necessarily generated.
Therefore, no effective measurement method has been currently available for calculation of the elongation of a high-temperature tensile sample. Because the high-temperature tensile sample has the characteristics of uneven temperature, uneven deformation and the like in a high-temperature state, the elongation of the sample cannot be calculated simply by dividing the difference between the length of the broken sample and the original length by the original length, and a more effective and accurate method for measuring the elongation of the high-temperature tensile sample is also required.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention provides a method for measuring the elongation of a high-temperature tensile sample. The elongation of the high-temperature tensile sample can be effectively and accurately measured.
In order to achieve the above purpose, the invention is realized by adopting the following technical scheme:
the method for measuring the elongation of the high-temperature tensile sample specifically comprises the following steps:
step 1) obtaining a sample through a simulation experiment.
The method comprises the steps of selecting a cylindrical body with a rod-shaped simulated sample, heating, preserving heat and reducing temperature of the simulated sample according to a preset experimental scheme through a thermal simulation tester, and stretching until the sample is broken, so that the sample which is broken into two sections is obtained.
The two sections of samples are coaxially connected into a whole, and the two sections of samples are connected into a state when the samples are stretched and disconnected instantly through magnetization or adhesion.
Step 2) using a solution which does not react with the sample, taking a container which is full of the solution, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted sample in the step (1) in the solution along the direction perpendicular to the liquid level of the solution, wherein the axis of the two sections of the butted sample is perpendicular to the liquid level of the solution.
In the process of implantation, two modes can be adopted: firstly, the same distance d and mm are used for descending each time; and secondly, the sample descends at a constant speed, wherein the descending speed is v, mm/s.
When the sample descends, recording the rise H of the liquid level of the solution, and measuring the height of the sample; the total volume V, ml of the solution and the sample immersed therein.
Step 3) a relation curve between the total volume V of the solution and the sample immersed therein and the sample falling distance d, or a relation curve between the total volume V of the solution and the sample immersed therein and the sample falling time t is drawn in step 2.
The curve shows a straight rise immediately after the sample is immersed in the solution. The slope of the curve also decreases as the plateau of the sample is immersed in the solution. As the sample continues to drop to another segment, the slope of the curve increases. Finally, the curve is in a straight line rising state.
And 4) carrying out first-order differentiation on the curve based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the sample falling distance d or the slope of the curve along with the sample falling time.
The cross-sectional area of the sample immersed in the solution begins to decrease, i.e., enters the region where deformation of the sample begins to occur, which is designated as a. The point when the volume increase returns to a constant value again is denoted B.
The graph shows that the part between the two points A, B corresponds to the part of the sample which is subjected to elongation deformation, so that the length of the part of the sample which is actually deformed can be determined, namely the length L of the deformed part of the sample after being stretched corresponds to the distance L, mm from A to B of the sample to the solution.
If the point A corresponds to the sample falling distance d 1 Mm, point B corresponds to a sample falling distance d 2 Mm, then
L＝d 2 -d 1 (1)
If the point A corresponds to the sample falling time t 1 The points s and B correspond to the sample falling time t 2 S, s is then
L＝(t 2 -t 1 )×v (2)
And 5) calculating the elongation of the sample after high-temperature stretching. Measuring the original length l of the sample 0 Mm, the length l of the two samples joined into the sample in step 1 is measured 1 Mm, the deformation amount DeltaL mm of high-temperature stretching is
ΔL＝l 1 -l 0 (3)
Step 6) calculation of elongation of the high-temperature tensile sample.From the L and DeltaL determined in step 4 and step 5, the original length L of the portion of the sample where the deformation actually occurs can be determined 0 Is that
L 0 ＝L-ΔL (4)
The elongation lambda,%, is obtained according to the elongation calculation formula
The elongation of the sample after high temperature stretching can be obtained by the formula (5).
Compared with the prior art, the method has the beneficial effects that:
according to the invention, through establishing the relation curve of the volume increment and the sample falling distance or the sample uniform falling time caused in the process of immersing the sample in the solution, the point corresponding to the actual deformation of the sample is accurately found, so that the length of the high-temperature tensile sample which is actually deformed can be accurately determined, the length of the whole sample is not used as the original length for calculating the elongation, and the elongation of the high-temperature tensile sample can be more reasonably and accurately measured under the condition of fully considering the deformation unevenness of the high-temperature tensile sample.
Drawings
FIG. 1 is a schematic representation of the relationship between the total volume V of the solution of the present invention and the sample immersed therein and the sample drop distance d;
FIG. 2 is a graphical representation of the relationship between the total volume V of the solution of the invention and the sample immersed therein and the sample drop time t;
FIG. 3 is a graphical representation of the total volume increase DeltaV of the solution of the present invention and the sample immersed therein versus the sample drop distance d;
FIG. 4 is a graphical representation of the total volume increase DeltaV of the solution of the present invention and the sample immersed therein versus sample drop time t;
FIG. 5 is a graph showing the relationship between the total volume V of the solution and the sample immersed therein and the sample drop distance d measured in examples 1, 3, and 5 of the present invention;
FIG. 6 is a graph showing the relationship between the total volume increment DeltaV of the solutions measured in examples 1, 3, 5 of the present invention and the immersed sample and the sample falling distance d;
FIG. 7 is a graph showing the relationship between the total volume V of the solutions measured in examples 2, 4 and 6 of the present invention and the sample immersed therein and the sample falling time t;
FIG. 8 is a graph showing the relationship between the total volume increment DeltaV of the solutions and the specimens immersed therein and the specimen falling time t measured in examples 2, 4, and 6 of the present invention.
Detailed Description
The invention discloses a method for measuring the elongation of a high-temperature tensile sample. Those skilled in the art can, with the benefit of this disclosure, suitably modify the process parameters to achieve this. It is expressly noted that all such similar substitutions and modifications will be apparent to those skilled in the art, and are deemed to be included in the present invention. While the methods and applications of this invention have been described in terms of preferred embodiments, it will be apparent to those skilled in the relevant art that variations and modifications can be made in the methods and applications described herein, and in the practice and application of the techniques of this invention, without departing from the spirit or scope of the invention.
The method for measuring the elongation of the high-temperature tensile sample specifically comprises the following steps:
and step 1, obtaining a sample through a simulation experiment. The method comprises the steps of selecting a cylindrical body with a rod-shaped simulated sample, heating, preserving heat and reducing temperature of the simulated sample according to a preset experimental scheme by using a thermal simulation tester, and stretching the simulated sample at 600-1400 ℃ until the sample is broken, so as to obtain the sample broken into two sections.
Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. The two sections of samples are coaxially connected into a whole, and the two sections of samples can be connected into a state when the samples are stretched and disconnected instantly through magnetization or adhesion.
And 2, taking a container filled with a sufficient amount of solution, and placing the container on a horizontal plane, wherein the solution does not react with the sample. And (3) slowly placing the two sections of the butted sample in the step (1) in the solution along the direction perpendicular to the liquid level of the solution, wherein the axis of the two sections of the butted sample is perpendicular to the liquid level of the solution. In the process of implantation, two modes can be adopted: firstly, the same distance d and mm are used for descending each time; and secondly, the sample descends at a constant speed, wherein the descending speed is v, mm/s.
When the sample descends, recording the rise H of the liquid level of the solution, and measuring the height of the sample; total volume of solution and sample immersed therein, ml.
And 3, drawing a relation curve between the total volume of the solution and the sample immersed in the solution and the sample falling distance d or a relation curve between the total volume of the solution and the sample immersed in the solution and the sample falling time t in the step 2, as shown in fig. 1 and 2.
When the sample is immersed in the solution, the liquid level of the sample is raised, the volume of the solution is increased, the volume of the portion of the cylinder immersed in the solution is increased, and the curves are raised in a straight line because the sections of the cylinders are equal. When the mesa-shaped portion of the sample is immersed in the solution, the cross section at this time gradually decreases as the sample descends, and thus the slope of the curve decreases. When the sample continues to descend to another section, the section gradually increases along with the descent of the sample, so that the slope of the curve also increases, and finally, the bench-shaped part of the sample is fully immersed in the solution, the volume increment of the solution is only influenced by the volume of the part of the cylinder immersed in the solution, and the curve is in a straight-line ascending state.
And 4, performing first-order differentiation on the curve based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the falling distance d of the sample or the slope of the curve along with the falling time of the sample, as shown in fig. 3 and 4.
As can be seen from the figure, the curve value is constant at the beginning, and since the sample immersed in the solution portion is a cylinder, and in the case where the sample immersed portion is a cylinder, the total volume increase (volume increase) of the solution and the sample immersed therein is only related to the cross section of the cylinder, and therefore, when the sample begins to be immersed in the solution, the volume increase is a constant value, but as the sample decreases, the volume increase decreases, which indicates that the cross section area of the sample immersed in the solution begins to decrease, that is, enters the sample initial deformation region, and this point is denoted as a. As the sample continues to soak into the solution, the volume increase gradually decreases and then gradually increases, eventually tending to a constant value, corresponding to the change in cross-sectional area of the sample immersed in the solution, the point at which the volume increase returns to a constant value being designated B.
The graph shows that the part between the two points A, B corresponds to the part of the sample which is subjected to elongation deformation, so that the length of the part of the sample which is actually deformed can be determined, namely the length L of the deformed part of the sample after being stretched corresponds to the distance L, mm from A to B of the sample to the solution.
If the point A corresponds to the sample falling distance d 1 Mm, point B corresponds to a sample falling distance d 2 Mm, then
L＝d 2 -d 1 Formula (1)
If the point A corresponds to the sample falling time t 1 The points s and B correspond to the sample falling time t 2 S, s is then
L＝(t 2 -t 1 ) Xv formula (2)
And 5, calculating the elongation of the sample after high-temperature stretching. Measuring the original length l of the sample 0 Mm, the length l of the two samples joined into the sample in step 1 is measured 1 Mm, the deformation amount Delta Lmm of high-temperature stretching is
ΔL＝l 1 -l 0 Formula (3)
And 6, calculating the elongation of the high-temperature tensile sample. From the L and DeltaL determined in step 4 and step 5, the original length L of the portion of the sample where the deformation actually occurs can be determined 0 Is that
L 0 =l- Δl formula (4)
The elongation lambda,%, is obtained according to the elongation calculation formula
The elongation of the sample after high temperature stretching can be obtained by the formula (5).
The invention adopts the sample solution discharge method to measure the elongation after breaking of the high-temperature tensile sample, reflects the change rule of volume increment generated by the sample solution discharge by the change of the cross section area of the deformation part of the high-temperature tensile sample on the axis thereof, can accurately find the actual length of the deformation part of the sample after high-temperature stretching, and then obtains the length of the deformation part of the sample according to the actual elongation of the sample, thereby accurately measuring the elongation of the high-temperature tensile sample.
[ example ]
Example 1:
and step 1, obtaining a sample through a simulation experiment. The material is selected as a low carbon steel, and is processed into a simulated sample, and the size of the simulated sample is phi 10 multiplied by 120 mm.
Heating to 1300 deg.C, maintaining for 5 min, cooling to 1000 deg.C at 3 deg.C/s, maintaining for 1 min, and stretching at 1×10 -3 s -1 Until the sample is broken, a two-stage sample is obtained.
Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the implantation, each time lowered by the same distance of 0.5m.
And 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample descending distance in the step 2, as shown in fig. 5.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the falling distance d of the sample, as shown in fig. 6.
From the graph, the coordinates of the point a are (5.1, 78.5) and the coordinates of the point B are (21.5, 78.5), respectively, and the point a corresponds to a sample falling distance of 5.1mm and the point B corresponds to a sample falling distance of 21.5mm, respectively, and the l=16.4 mm is obtained by the formula (1).
Example 2:
and step 1, obtaining a sample through a simulation experiment. Selecting low-carbon steel as a material, processing into a cylinder with the size of phi 10 multiplied by 120mm as a simulation sample, heating to 1300 ℃ by a thermal simulation tester, preserving heat for 5 minutes, cooling to 1000 ℃ at the speed of 3 ℃/s, preserving heat for 1 minute, and stretching at the stretching speed of 1 multiplied by 10 -3 s -1 Until the sample is broken, a two-stage sample is obtained.
Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the insertion, the sample descends at a constant speed, v=1 mm/s.
And 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample falling time in the step 2, as shown in fig. 7.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the sample falling time t, as shown in fig. 8.
From the graph, the coordinates of the point a are (5.1, 78.5) and the coordinates of the point B are (21.5, 78.5), respectively, the point a corresponds to a sample falling time of 5.1s and the point B corresponds to a sample falling time of 21.5s, respectively, and the l=16.4 mm is obtained by the formula (2)
Example 3:
and step 1, obtaining a sample through a simulation experiment. Selecting low-carbon steel as a material, processing into a cylinder with the size of phi 10 multiplied by 120mm as a simulation sample, heating to 1300 ℃ by a thermal simulation tester, preserving heat for 5 minutes, cooling to 700 ℃ at the speed of 3 ℃/s, preserving heat for 1 minute, and stretching at the stretching speed of 1 multiplied by 10 -3 s -1 Until the sample is broken, a two-stage sample is obtained. Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the implantation, each time the same distance of 0.5 mm is decreased;
and 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample descending distance in the step 2, as shown in fig. 5.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the falling distance d of the sample, as shown in fig. 6. The coordinates of the point a corresponding to 3.5, 78.5 and the coordinates of the point B corresponding to 15.5, 78.5 were obtained, the drop distance of the point a corresponding to 3.5mm and the drop distance of the point B corresponding to 15.5mm, and l=12.0 mm was obtained by the formula (1).
Example 4:
and step 1, obtaining a sample through a simulation experiment. Selecting low-carbon steel as a material, processing into a cylinder with the size of phi 10 multiplied by 120mm as a simulation sample, heating to 1300 ℃ by a thermal simulation tester, preserving heat for 5 minutes, cooling to 700 ℃ at the speed of 3 ℃/s, preserving heat for 1 minute, and stretching at the stretching speed of 1 multiplied by 10 -3 s -1 Until the sample is broken, a two-stage sample is obtained. Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the insertion, the sample descends at a constant speed, v=1 mm/s.
And 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample falling time in the step 2, as shown in fig. 7.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the sample falling time t, as shown in fig. 8. The coordinates of the point a corresponding to 3.5, 78.5 and the coordinates of the point B corresponding to 15.5, 78.5 are obtained from the curve, the point a corresponding to 3.5s for the sample falling time and the point B corresponding to 15.5s for the sample falling time, and l=12.0 mm is obtained from the formula (2)
Example 5:
and step 1, obtaining a sample through a simulation experiment. Selecting and usingThe material is a low carbon steel, and is processed into a simulated sample, a cylinder with the size of phi 10 multiplied by 120mm, the simulated sample is heated to 1300 ℃ by a thermal simulation tester, the temperature is kept for 5 minutes, then the temperature is reduced to 1200 ℃ at the speed of 3 ℃/s, and then the temperature is kept for 1 minute for stretching, and the stretching speed is set to be 1 multiplied by 10 -3 s -1 Until the sample is broken, a two-stage sample is obtained. Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the implantation, each time lowered by the same distance of 0.5 mm.
And 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample descending distance in the step 2, as shown in fig. 5.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the falling distance d of the sample, as shown in fig. 6. The coordinates of the corresponding point a were found to be (6.3, 78.5) and the coordinates of the corresponding point B were found to be (16.5, 78.5), respectively, the falling distance of the corresponding point a to the sample was found to be 6.3mm, the falling distance of the corresponding point B to the sample was found to be 16.5mm, and the l=10.2 mm was found by the formula (1)
Example 6:
and step 1, obtaining a sample through a simulation experiment. Selecting low-carbon steel as a material, processing into a cylinder with the size of phi 10 multiplied by 120mm as a simulation sample, heating to 1300 ℃ by a thermal simulation tester, preserving heat for 5 minutes, cooling to 1200 ℃ at the speed of 3 ℃/s, and preserving heatStretching was performed at 1 min at a stretching rate of 1X 10 -3 s -1 Until the sample is broken, a two-stage sample is obtained. Based on the deformation behavior characteristics of the sample at high temperature, the sample is broken into two sections, one end of each section near the fracture is in a table shape, and the other parts are in a cylinder shape. Two sections of samples are magnetized, and the butt joint coaxial is integrated.
And 2, taking a container for containing water to be measured, and placing the container on a horizontal plane. And (3) slowly placing the two sections of the butted samples in the step (1) in the solution, wherein the axes of the two sections of the butted samples are perpendicular to the liquid level of water. During the insertion, the sample descends at a constant speed, v=1 mm/s.
And 3, drawing a relation curve between the total volume of the water and the sample in the water immersed part and the sample falling time in the step 2, as shown in fig. 7.
And 4, performing first-order differentiation based on the curve analysis drawn in the step 3 to obtain a change relation curve of the slope of the curve along with the sample falling time t, as shown in fig. 8. The coordinates of the point a corresponding to 6.3, 78.5 and the coordinates of the point B corresponding to 16.5, 78.5 are obtained from the curve, the drop distance of the point a corresponding to 6.3s and the drop distance of the point B corresponding to 16.5s are obtained from the formula (2), and l=10.2 mm
The invention adopts a liquid discharge method, fully considers the characteristics of uneven temperature, uneven deformation and the like of the high-temperature tensile sample in a high-temperature state, accurately finds out the point corresponding to the actual deformation of the sample by establishing a relation curve between the volume increment and the sample falling distance or the sample uniform falling time caused by the sample immersing in the solution, further accurately determines the actual deformation length of the high-temperature tensile sample, and can more accurately determine the elongation of the high-temperature tensile sample under the condition of fully considering the uneven deformation of the high-temperature tensile sample.
According to the invention, through establishing the relation curve of the volume increment and the sample falling distance or the sample uniform falling time caused in the process of immersing the sample in the solution, the point corresponding to the actual deformation of the sample is accurately found, so that the length of the high-temperature tensile sample which is actually deformed can be accurately determined, the length of the whole sample is not used as the original length for calculating the elongation, and the elongation of the high-temperature tensile sample can be more reasonably and accurately measured under the condition of fully considering the deformation unevenness of the high-temperature tensile sample.
The foregoing is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art, who is within the scope of the present invention, should make equivalent substitutions or modifications according to the technical scheme of the present invention and the inventive concept thereof, and should be covered by the scope of the present invention.
Claims (6)
1. The method for measuring the elongation of the high-temperature tensile sample specifically comprises the following steps:
step 1) adopting a rod-shaped sample, heating, preserving heat, cooling the sample, and then stretching the sample until the sample is broken to obtain a sample broken into two sections;
butting two sections of samples, coaxially forming a whole, and connecting the two sections of samples into a state when the samples are stretched and disconnected;
step 2) injecting the solution into a container by adopting the solution which does not react with the sample, and placing the container on a horizontal plane; placing the axis of the butted sample in the solution along the direction perpendicular to the liquid level of the solution, wherein the axis of the butted sample is perpendicular to the liquid level of the solution;
the same distance d and mm are decreased each time in the process of placement;
when the sample descends, recording the rise H of the liquid level of the solution, and measuring the height of the sample; the total volume V, ml of the solution and the sample immersed therein;
step 3) drawing a relation curve between the total volume V of the solution and the sample immersed in the solution and the sample falling distance d in the step 2);
step 4) performing first-order differentiation on the curve based on the curve analysis drawn in the step 3) to obtain a change relation curve of the slope of the curve along with the descending distance d of the sample;
the cross-sectional area of the sample immersed in the solution begins to decrease, i.e., enters the region where deformation of the sample begins to occur, which is designated as a; the point when the volume increment is restored to a constant value is marked as B;
it can be seen from the graph that the portion between the two points A, B corresponds to the portion of the sample subjected to elongation deformation;
if the point A corresponds to the sample falling distance d 1 Mm, point B corresponds to a sample falling distance d 2 Mm, then
L＝d 2 -d 1 (1)
Step 5), calculating the elongation of the sample after high-temperature stretching; measuring the original length l of the sample 0 Mm, the length l of the two samples joined into the sample in step 1) is measured 1 Mm, the deformation amount DeltaL mm of high-temperature stretching is
ΔL＝l 1 -l 0 (3)
Step 6) calculating the elongation of the high-temperature tensile sample; determining the original length L of the actual deformation part of the sample according to the L and the delta L determined in the step 4) and the step 5) 0 Is that
L 0 ＝L-ΔL (4)
The elongation lambda,%, is obtained according to the elongation calculation formula
The elongation of the sample after high temperature stretching was obtained from the formula (5).
2. The method for measuring elongation of a high-temperature tensile specimen according to claim 1, wherein the step 1) is performed by using a rod-like cylindrical specimen.
3. The method for measuring the shrinkage of a high-temperature tensile sample according to claim 1, wherein the step 1) is to heat, keep warm and cool the simulated sample according to a predetermined experimental scheme by a thermal simulation tester, and then stretch the simulated sample until the simulated sample is broken to obtain a two-section simulated sample.
4. The method for measuring the shrinkage of a tensile test specimen at high temperature according to claim 1, wherein said step 1) is a step of joining two test specimens by magnetization or adhesion to a state at the moment of tensile break of the test specimen.
5. The method for measuring the shrinkage of a section of a high-temperature tensile sample according to claim 1, wherein in the step 2), the sample is dropped at a constant speed during the insertion process, and the dropping speed is v, mm/s;
step 3) drawing a relation curve between the total volume V of the solution and the sample immersed in the solution and the sample falling time t;
step 4) performing first-order differentiation on the curve to obtain a change relation curve of the slope of the curve along with the falling time of the sample; if the point A corresponds to the sample falling time t 1 The points s and B correspond to the sample falling time t 2 S, s is then
L＝(t 2 -t 1 )×v (2)。
6. The method for measuring the shrinkage of a high-temperature tensile sample according to claim 1, wherein the curve of the step 3) is straight when the sample is immersed in the solution; the slope of the curve decreases as the plateau of the sample is immersed in the solution; when the sample continues to descend to another section, the slope of the curve is increased; finally, the entire mesa-shaped portion of the sample is immersed in the solution, and the curve is again in a straight-line rising state.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1035157A (en) * | 1987-12-24 | 1989-08-30 | 西屋电气公司 | The determining method of turbine blade cross-section area and device thereof |
| US20070151359A1 (en) * | 2005-12-29 | 2007-07-05 | Accellent, Inc. | Method for measuring and calculating tensile elongation of ductile metals |
| US20170038200A1 (en) * | 2014-04-10 | 2017-02-09 | Peracutus Holding B.V. | Process for the determination of the cross-sectional area and volume of an object |
| CN108489820A (en) * | 2018-02-13 | 2018-09-04 | 鞍钢股份有限公司 | Method for acquiring true stress of high-temperature tensile test |
| CN109870354A (en) * | 2019-01-21 | 2019-06-11 | 吉林大学 | Round metal bars sample is uniaxially stretched elongation after fracture method for automatic measurement |
-
2023
- 2023-03-23 CN CN202310290709.9A patent/CN116337642A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1035157A (en) * | 1987-12-24 | 1989-08-30 | 西屋电气公司 | The determining method of turbine blade cross-section area and device thereof |
| US20070151359A1 (en) * | 2005-12-29 | 2007-07-05 | Accellent, Inc. | Method for measuring and calculating tensile elongation of ductile metals |
| US20170038200A1 (en) * | 2014-04-10 | 2017-02-09 | Peracutus Holding B.V. | Process for the determination of the cross-sectional area and volume of an object |
| CN108489820A (en) * | 2018-02-13 | 2018-09-04 | 鞍钢股份有限公司 | Method for acquiring true stress of high-temperature tensile test |
| CN109870354A (en) * | 2019-01-21 | 2019-06-11 | 吉林大学 | Round metal bars sample is uniaxially stretched elongation after fracture method for automatic measurement |
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