Device and method for detecting thermal shock resistance and accident resistance of material

Abstract

According to the device for detecting the thermal shock resistance and accident resistance of the material, lifting equipment is arranged on a supporting frame and is used for driving a heavy hammer to move; the electromagnet is installed on the supporting frame and arranged above the heavy hammer. The base is fixedly installed at the bottom of the supporting frame. The driving rod is slidably mounted on the base, and the heavy hammer presses the driving rod to move when falling down; the driving shaft is rotationally mounted on the base; when sliding, the driving rod drives the driving shaft to rotate through the linkage mechanism; the impact test bar is replaced according to an actual working condition needing to be simulated and is fixedly mounted on the driving shaft; the clamp is mounted on the base to clamp a material test block; when the driving shaft rotates, the impact test bar generates friction on the material test block; the heating coil is driven by telescopic equipment mounted on the support frame to move and is used for heating the impact test bar; the water spraying equipment is mounted on the supporting frame and used for spraying water to the impact test bar; contact type thermal shock in an actual production environment is simulated in a mode that the impact test bar repeatedly rubs the material test block.

Description

Technical Field

[0001] The present invention relates to the technical field of performance detection, and particularly to a device and a method for detecting the thermal shock resistance and accident resistance performance of materials. Background Art

[0002] When an object is rapidly heated and then cooled, resulting in a drastic temperature change, the object will be subjected to the action of thermal shock stress. In the case of rapid heating followed by rapid cooling, a large temperature gradient will lead to a large thermal shock stress. In actual working conditions, the rapid high temperature generated by the extrusion and friction between workpieces due to accidents is also a source of a large amount of heat. When the stress generated thereby acts on the workpiece at a relatively fast speed and in the form of an impact, the workpiece is prone to failure.

[0003] In actual production, there are many examples of component failure caused by thermal shock. For example, when a rolling mill experiences rolling accidents such as strip breakage and steel sticking during operation, the rapid heating and rapid cooling caused by the accident will increase the local temperature gradient of the roll surface, and the thermal shock stress will also increase accordingly. When this stress acts on the local surface of the roll body at a relatively fast speed and in the form of an impact, the roll body is prone to failure and spalling. Another example is that during the operation of a shearer pick, it cuts coal for half a cycle and idles for half a cycle as the drum rotates. When cutting coal, the shearer pick will crush and cut the coal seam under the action of a very large thrust, and the tool tip will touch the coal wall, generating intense friction and a rapid temperature rise. When idling, the cooling effect of air and water spray (aiming to reduce dust) will rapidly lower the temperature of the cutting face. Such rapid heating and rapid cooling will increase the temperature gradient of the material, generating a strong thermal shock stress and causing the shearer pick to fail. Similar situations are also often seen in interrupted cutting tools such as milling cutters and turbine blades.

[0004] In actual working conditions, thermal shock stress inevitably occurs due to accidents. Therefore, for workpieces, thermal shock resistance is a very important indicator, and thermal shock resistance performance detection is an important part of workpiece detection. Currently, there are already experimental devices for simulating thermal shock.

[0005] The invention patent with the publication number CN112504899B discloses a thermal shock experiment system, including: a first environment module, which is provided with a first sealed heat insulation layer, a first water cooling device, and a first heating device; a second environment module, which is arranged below the first environment module, and there is a sealed heat insulation hatch between the second environment module and the first environment module. The second environment module is provided with a second sealed heat insulation layer, a second water cooling device, and a second heating device; a vacuum device, which is respectively connected to the two environment modules and is suitable for providing different pressure environments for the test piece; an inflation device, which is respectively connected to the two environment modules and is suitable for filling oxygen or inert gas into the two environment modules so as to provide different oxygen partial pressure environments for the test piece; a medium storage tank, which is suitable for storing the medium and is arranged in the second environment module; the test piece is suitable for moving from the first environment module to the second environment module along the guiding wire to form a thermal shock on the test piece.

[0006] The invention patent with the publication number CN108387476A discloses a device for testing the thermal shock resistance of large-sized test pieces / structural components, which includes a test piece placement cavity for placing large-sized test pieces / structural components, in which a test piece holder is placed, and it is composed of a high-strength graphite bracket, a heat insulation carbon felt, a graphite paper, and a large-sized test piece. The test piece holder is placed on the sealed heat insulation hatch between the test piece placement cavity and the environment state control cavity that can achieve a diverse and complex thermal environment. By realizing different thermal environments in the environment state control cavity and then opening the sealed heat insulation hatch between the two cavities, the rapid expansion of the environment module space can be achieved, and a thermal shock can be applied to the large-sized test piece in the expanded space.

[0007] However, both of the above two inventions have the following deficiencies: 1. Using a non-contact thermal shock detection method, the working condition effect of contact thermal shock cannot be simulated; 2. The working condition effect of abnormal extrusion force on the material cannot be simulated; 3. Too many cycles may cause thermal fatigue failure and the simulation effect is not good. Summary of the Invention

[0008] In view of the above problems, the present invention proposes a device for detecting the thermal shock resistance and accident resistance performance of materials, and the technical solution used is: A device for detecting the thermal shock resistance and accident resistance performance of materials, including a support frame, a lifting device, an electromagnet, a weight, a base, a driving rod, a driving shaft, an impact test rod, a fixture, a heating coil, and a water spraying device; The lifting device is arranged on the support frame and is used to drive the weight to move; the electromagnet is installed on the support frame and is arranged above the weight to intermittently adsorb the weight; The base is fixedly installed at the bottom of the support frame; the driving rod is slidably installed on the base and is located directly below the weight. When the weight falls, it presses the driving rod to move; the driving shaft is rotatably installed on the base; when the driving rod slides, it drives the driving shaft to rotate through a linkage mechanism; The impact test rod is replaced according to the actual working conditions to be simulated and is fixedly installed on the driving shaft; the fixture is installed on the base and is used to clamp the material test block for performance testing; when the driving shaft rotates, the impact test rod generates friction on the material test block; the heating coil is driven to move by a telescopic device installed on the support frame, and the heating coil is used to heat the impact test rod; The water spraying device is installed on the support frame and is used to spray water on the impact test rod.

[0009] Further, the linkage mechanism includes a driving rack and a driving gear. The driving rack is fixedly installed on the driving rod, and the driving gear is coaxially and fixedly installed on the driving shaft and meshes with the driving rack.

[0010] Further, the lifting device adopts a winch, and the weight is fixedly installed on the steel wire rope of the winch.

[0011] Further, a tray is fixedly installed on the base. A through hole corresponding to the driving rod is provided on the bottom surface of the tray, and the rod body of the driving rod passes through the through hole of the tray. After the weight presses the driving rod to fall, it lands on the tray.

[0012] Further, a spring positioning pin is installed on the base for positioning the driving rod.

[0013] Further, a thermometer is also included and is installed on the base for detecting the temperature.

[0014] Further, a reset assembly for driving the driving rod back to its original position is also included; the reset assembly includes a reset motor, an input gear, and an output gear; the reset motor is installed on the base, and its output end can rotate freely in the power-off state; the input gear is coaxially and fixedly installed on the output end of the reset motor, and the output gear is coaxially and fixedly installed on the driving shaft and meshes with the input gear.

[0015] Further, a control terminal mounting plate fixedly installed on the support frame is also included, and a control terminal electrically connected to each electrical component is installed thereon for controlling the operation of the entire device.

[0016] A method for detecting the thermal shock and accident resistance performance of materials, based on the above-mentioned device for detecting the thermal shock and accident resistance performance of materials, is characterized by including the following steps: S1, actually select the impact test rod corresponding to the material according to the working conditions to be simulated, and fixedly install the impact test rod on the driving shaft; fix the material test block for performance testing on the fixture; S2. The electromagnet adsorbs the weight, and the lifting device sets the falling height of the weight; check the reset condition of the driving rod to ensure that the driving rod returns to its original position. S3. According to the actual process requirements, determine whether it is necessary to heat the impact test rod; if heating is required, it is a hot-state impact test. The telescopic device drives the heating coil to move, and the heating coil heats the impact test rod to the required temperature. After heating is completed, the telescopic device drives the heating coil back to its original position; if no heating is required, it is a cold-state impact test. S4. According to the actual process requirements, determine whether it is necessary to spray water during the simulation. If water spraying is required, start the water spraying device. S5. The electromagnet releases the weight, and the weight falls on the top of the driving rod and drives the driving rod to rapidly descend. The driving shaft is rotated through the linkage mechanism, causing the impact test rod to move around the driving shaft and generate a friction scratch on the material test block, simulating a thermal shock accident. S6. The lifting device drives the weight to rise, and the electromagnet adsorbs the weight; the driving rod returns to its original position, and the material test block is removed. S7. Observe the material test block, conduct longitudinal wire cutting detection, metallographic detection, hardness change detection, etc., to judge the thermal shock and accident resistance performance of the material test block.

[0017] Further, in step two, calculate the energy required to bend the impact test rod according to the following formula, and then calculate the corresponding height of the weight based on the energy:

[0018] Wherein, is the energy required for bending, is the flexural strength, is the diameter of the impact test rod, is the bending angle.

[0019] Since the present invention adopts the above technical solutions, the present invention has the following advantages: 1. Different from the existing non-contact thermal shock test, the present invention simulates the contact thermal shock in the actual production environment by repeatedly rubbing the material test block with the impact test rod, can simulate the abnormal extrusion force situation of the material test block, and avoids the tissue damage that may occur in the case of thermal fatigue of the material test block; and the present invention can simply replace the impact test rods of different materials to simulate various materials that can have contact friction in actual production and processing, with a wide range of applications.

[0020] 2. The present invention heats the impact test rod according to the actual working conditions to select a hot-state impact test or a cold-state impact test, and controls the opening and closing of the water spraying device according to whether water spraying is required in the actual working conditions, meeting the simulation requirements of various contact thermal shocks in a large number of actual production working environments and expanding the application range. Description of the Drawings

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0022] Figure 2 This is a schematic diagram of the structure of the present invention after removing the support frame.

[0023] Figure 3 This is a schematic assembly structure diagram of the lifting device, electromagnet and weight of the present invention.

[0024] Figure 4 This is a front schematic diagram of the structure of the present invention after removing the support frame, lifting device, electromagnet and weight.

[0025] Figure 5 This is a rear schematic diagram of the structure of the present invention after removing the support frame, lifting device, electromagnet and weight.

[0026] Reference numerals in the drawings: 1 - Support frame; 2 - Lifting device; 3 - Electromagnet; 4 - Weight; 5 - Base; 6 - Tray; 7 - Driving rod; 8 - Linkage mechanism; 801 - Driving rack; 802 - Driving gear; 9 - Driving shaft; 10 - Impact test rod; 11 - Fixture; 12 - Heating coil; 13 - Telescopic device; 14 - Water spraying device; 15 - Temperature measuring instrument; 16 - Reset assembly; 1601 - Reset motor; 1602 - Input gear; 1603 - Output gear; 17 - Control terminal mounting plate; 18 - Material test block. Detailed implementation manners

[0027] The technical solution of the present invention will be further specifically described below through embodiments in conjunction with the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0028] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "in", "out", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the present invention is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Embodiment:

[0029] This embodiment discloses a device for detecting the thermal shock resistance and accident resistance performance of materials, such as Figure 1 - Figure 2As shown in the figure, it includes a support frame 1, a lifting device 2, an electromagnet 3, a weight 4, a base 5, a drive rod 7, a linkage mechanism 8, a drive shaft 9, an impact test rod 10, a fixture 11, a heating coil 12 and a water spraying device 14.

[0030] As shown in 1- Figure 3 As shown in the figure, the lifting device 2 is arranged at the top of the support frame 1 and is used to drive the weight 4 to move in the vertical direction; in this embodiment, the lifting device 2 adopts a winch, and the weight 4 is fixedly installed on the steel wire rope of the winch; the electromagnet 3 is installed on the support frame 1 through a bracket and is arranged above the weight 4; in this embodiment, the electromagnet 3 adopts a DC ring electromagnet.

[0031] As Figure 1 - Figure 2 and Figure 4 - Figure 5 As shown in the figure, the base 5 is fixedly installed at the bottom of the support frame 1, and a drive rod guide rail is provided thereon; the tray 6 is fixedly installed at the top of the drive rod guide rail, and a through hole corresponding to the drive rod 7 is provided on the bottom surface of the tray 6; the drive rod 7 is arranged directly below the weight 4 and is vertically slidably installed on the drive rod guide rail. The rod body of the drive rod 7 passes through the through hole of the tray 6, and a receiving plate for receiving the weight 4 is fixedly provided at the top of the drive rod 7; a spring positioning pin is installed on the drive rod guide rail for positioning the drive rod 7; the weight 4 presses the drive rod 7 to fall and land on the tray 6; The drive shaft 9 is rotatably installed on the base 5, and its axis is horizontally arranged; the impact test rod 10 is fixedly installed on the drive shaft 9; the linkage mechanism 8 uses the linear motion of the drive rod 7 as the power to drive the drive shaft 9 to rotate; in this embodiment, the linkage mechanism 8 includes a drive rack 801 and a drive gear 802. The drive rack 801 is fixedly installed on the drive rod 7, and the drive gear 802 is coaxially and fixedly installed on the drive gear 802 and meshes with the drive rack 801; The fixture 11 is installed on the base 5 and is used to clamp the material test block 18 for performance testing; in this embodiment, the fixture 11 adopts a bench vice, and the vise body of the bench vice is slidably installed on the base 5; After the fixture 11 fixes the material test block 18, the rotation of the drive shaft 9 will drive the impact test rod 10 to rotate, and the impact test rod 10 will generate friction scratches on the material test block 18 to simulate the contact thermal shock effect; the impact test rod 10 is replaced with corresponding materials according to the actual working conditions to be simulated, such as a soft steel bar and annealed No. 20 steel; the impact test rod 10 is fixedly installed on the drive shaft 9, and the impact test rod 10 can be bent at a certain angle; The heating coil 12 is driven by the telescopic device 13 to move up and down for heating the impact test rod 10; in this embodiment, the telescopic device 13 adopts a servo cylinder, and the cylinder body is fixedly installed on the support frame 1; when the impact test rod 10 is kept vertical, the heating coil 12 is driven by the telescopic device 13 to move downward to cover the impact test rod 10 and heat the impact test rod 10; The water spraying device 14 is installed on the base 5 and is used to spray water on the impact test rod 10.

[0032] The device further includes a thermometer 15, a reset component 16, and a control terminal mounting plate 17; The thermometer 15 is installed on the base 5 and is used to detect the temperature; The reset component 16 is used to drive the drive rod 7 back to its original position. In this embodiment, the reset component 16 includes a reset motor 1601, an input gear 1602, and an output gear 1603; the reset motor 1601 is installed on the base 5, and its output end can rotate freely in the power-off state; the input gear 1602 is coaxially and fixedly installed on the output end of the reset motor 1601, and the output gear 1603 is coaxially and fixedly installed on the drive shaft 9 and meshes with the input gear 1602; when the drive rod 7 moves downward, the reset motor 1601 is powered off, and the drive shaft 9 drives the input gear 1602 to rotate freely through the output gear 1603. When the drive rod 7 is ready to move upward, the reset motor 1601 is started. The output end of the reset motor 1601 drives the input gear 1602 to rotate, the input gear 1602 drives the output gear 1603 to rotate, thereby driving the drive shaft 9 to rotate. Through the linkage mechanism 8, the drive rod 7 moves upward, and finally the drive rod 7 returns to its original position and is positioned by the spring positioning pin; The control terminal mounting plate 17 is fixedly installed on the support frame 1, and a control terminal electrically connected to each electrical component is installed thereon, which is used to control the operation of the entire device.

[0033] Based on the above device, a method for detecting the thermal shock and accident resistance performance of materials is as follows: Step 1, actually select the impact test rod 10 of the corresponding material according to the working conditions to be simulated, and fixedly install the impact test rod 10 on the drive shaft 9; fixedly install the material test block 18 for performance detection on the fixture 11; Step 2, the electromagnet 3 adsorbs the weight 4, and the lifting device 2 sets the falling height of the weight 4; check the reset situation of the drive rod 7 to determine that the drive rod 7 returns to its original position; Step 3, according to the actual process requirements, determine whether it is necessary to heat the impact test rod 10; if heating is required, it is a hot state impact test. The telescopic device 13 drives the heating coil 12 to move, and the heating coil 12 heats the impact test rod 10 to the required temperature. After heating is completed, the telescopic device 13 drives the heating coil 12 back to its original position; if no heating is required, it is a cold state impact test; Step 4, according to the actual process requirements, determine whether it is necessary to spray water during the simulation. If water spraying is required, start the water spraying device 14; Step 5: The electromagnet 3 releases the weight 4, and the weight 4 falls on the top of the drive rod 7 and drives the drive rod 7 to quickly descend. The drive rack 801 drives the drive gear 802 to rotate, and the drive shaft 9 rotates accordingly, causing the impact test rod 10 to move around the drive shaft 9 and generate a friction scratch on the material test block 18 to simulate a thermal shock accident. Step 6: The lifting device 2 drives the weight 4 to rise, and the electromagnet 3 adsorbs the weight 4; the drive rod 7 returns to its original position, and the material test block 18 is removed. Step 7: Observe the material test block 18, conduct longitudinal wire cutting detection, metallographic detection, hardness change detection, etc., to judge the thermal shock and accident resistance performance of the material test block 18.

[0034] Specifically, in Step 2, calculate the energy required to bend the impact test rod 10 according to the following formula, and then calculate the corresponding height of the weight based on the energy:

[0035] where is the energy required for bending (J), is the flexural strength (Pa), is the diameter of the impact test rod 10 (m), is the bending angle (rad); Taking annealed No. 20 steel as an example, , , the fold angle , the moment of inertia of the cross-section , the distance of the neutral axis , the bending moment , the bending energy , slightly increase this energy by 10% to ensure the smooth completion of the test, and then calculate the corresponding height of the weight according to the law of conservation of energy.

[0036] Specifically, in Step 3, the heating coil 12 adopts the intermediate frequency induction coil heating method, and the heating time is controlled by the thermometer 15.

[0037] Specifically, in Step 7, when observing with the naked eye, judge the thermal shock and accident resistance performance by observing whether there are cracks in the scratch morphology state of the material test block 18, the morphology, area, and distribution and state of the steel adhesion; during the longitudinal wire cutting detection, conduct metallographic detection on the depth and tissue changes of the heat affected zone, observe the depth and distribution of cracks, detect the change of hardness. The shallower the crack or the absence of cracks indicates good thermal shock and accident resistance performance, and vice versa, the deeper, more, and denser the cracks are, the worse the thermal shock and accident resistance performance is.

Claims

1. A device for detecting the thermal shock and accident resistance performance of materials, characterized in that It includes a support frame (1), a lifting device (2), an electromagnet (3), a weight (4), a base (5), a drive rod (7), a drive shaft (9), an impact test rod (10), a fixture (11), a heating coil (12) and a water spraying device (14); The lifting device (2) is arranged on the support frame (1) and is used to drive the weight (4) to move; the electromagnet (3) is installed on the support frame (1) and is arranged above the weight (4) to intermittently adsorb the weight (4); The base (5) is fixedly installed at the bottom of the support frame (1); the drive rod (7) is slidably installed on the base (5) and is located directly below the weight (4), and the weight (4) presses the drive rod (7) to move when it falls; the drive shaft (9) is rotatably installed on the base (5); when the drive rod (7) slides, it drives the drive shaft (9) to rotate through a linkage mechanism (8); The impact test rod (10) is replaced according to the actual working conditions to be simulated and is fixedly installed on the drive shaft (9); the fixture (11) is installed on the base (5) and is used to clamp the material test block (18) for performance testing; when the drive shaft (9) rotates, the impact test rod (10) generates friction on the material test block (18); the heating coil (12) is driven to move by a telescopic device (13) installed on the support frame (1), and the heating coil (12) is used to heat the impact test rod (10); The water spraying device (14) is installed on the support frame (1) and is used to spray water on the impact test rod (10).

2. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, wherein, The linkage mechanism (8) includes a drive rack (801) and a drive gear (802), the drive rack (801) is fixedly installed on the drive rod (7), and the drive gear (802) is coaxially and fixedly installed on the drive gear (802) and meshes with the drive rack (801).

3. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, wherein, The lifting device (2) uses a winch, and the weight (4) is fixedly installed on the steel wire rope of the winch.

4. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, characterized in that, A tray (6) is fixedly installed on the base (5), a through hole corresponding to the drive rod (7) is provided on the bottom surface of the tray (6), the rod body of the drive rod (7) passes through the through hole of the tray (6), and the weight (4) lands on the tray (6) after pressing the drive rod (7) to fall.

5. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, wherein, A spring positioning pin is installed on the base (5) for positioning the drive rod (7).

6. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, characterized in that, It also includes a thermometer (15) installed on the base (5) for detecting temperature.

7. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, characterized in that, It also includes a reset assembly (16) for driving the drive rod (7) back to its original position; the reset assembly (16) includes a reset motor (1601), an input gear (1602) and an output gear (1603); the reset motor (1601) is installed on the base (5), and its output end can rotate freely in the power-off state; the input gear (1602) is coaxially and fixedly installed on the output end of the reset motor (1601), and the output gear (1603) is coaxially and fixedly installed on the drive shaft (9) and meshes with the input gear (1602).

8. The device for detecting the thermal shock resistance and accident resistance performance of materials according to claim 1, characterized in that, It further includes a control terminal mounting plate (17) fixedly installed on the support frame (1), on which there is a control terminal electrically connected to each electrical component for controlling the operation of the entire device.

9. A method for detecting the thermal shock and accident resistance performance of materials, based on the device for detecting the thermal shock and accident resistance performance of materials according to claim 1, characterized in that, It includes the following steps: S1. Actually select an impact test rod (10) made of corresponding material according to the working conditions to be simulated, and fixedly install the impact test rod (10) on the drive shaft (9); fixedly install the material test block (18) for performance detection on the fixture (11); S2. The electromagnet (3) adsorbs the weight (4), and the lifting device (2) sets the falling height of the weight (4); check the reset condition of the drive rod (7) to ensure that the drive rod (7) returns to its original position; S3. According to the actual process requirements, determine whether it is necessary to heat the impact test rod (10); if heating is required, it is a hot state impact test, and the telescopic device (13) drives the heating coil (12) to move, and the heating coil (12) heats the impact test rod (10) to the required temperature. After heating is completed, the telescopic device (13) drives the heating coil (12) back to its original position; if no heating is required, it is a cold state impact test; S4. According to the actual process requirements, determine whether it is necessary to spray water during the simulation. If spraying water is required, start the water spraying device (14); S5. The electromagnet (3) releases the weight (4), and the weight (4) falls on the top of the drive rod (7) and drives the drive rod (7) to quickly descend. The drive shaft (9) is driven to rotate through the linkage mechanism (8), so that the impact test rod (10) moves around the drive shaft (9) and generates a friction scratch on the material test block (18) to simulate a thermal shock accident; S6. The lifting device (2) drives the weight (4) to rise, and the electromagnet (3) adsorbs the weight (4); the drive rod (7) returns to its original position, and the material test block (18) is removed; S7. Observe the material test block (18), conduct longitudinal wire cutting detection, metallographic detection, hardness change detection, etc. to judge the thermal shock and accident resistance performance of the material test block (18).

10. The method for detecting the thermal shock and accident resistance performance of materials according to claim 9, characterized in that, In step two, calculate the energy required to bend the impact test rod (10) according to the following formula, and thus calculate the corresponding height of the weight according to the energy: ， Among them, is the energy required for bending, is the flexural strength, is the diameter of the impact test bar (10), is the bending angle.

Images