CN102980790B - The test unit of high temperature shot-peening and method - Google Patents

Abstract

The invention provides a test device for high-temperature shot peening, including an air compression system, a high-pressure air heating gun, a spray gun, a storage tank, a sample rotating mechanism, a sample clamping tool, and a sample temperature measurement system, wherein the air compression system, high-pressure The air heating gun and the spray gun are connected in sequence. The spray gun is placed under the high-pressure air heating gun. The side of the spray gun is connected to the storage tank. On the rotating mechanism, the sample temperature measurement system is connected to the sample holding tool, and the sample temperature measurement system is used to test the temperature of the sample at any time. Corresponding methods are also provided. The maximum shot peening temperature of the present invention reaches 400 degrees Celsius, which is beneficial to the improvement of the plasticity of the magnesium alloy and the deformation ability; the temperature of the sample is measured in the case of shot peening, which improves the accuracy of the experiment; it can be sprayed under a small negative pressure. shot, the minimum shot peening strength is 0.05mmN.

Description

Test device and method for high temperature shot peening

technical field

The invention relates to a device in the technical field of metal material processing, in particular to a high-temperature shot peening machine for performing surface deformation strengthening treatment on a magnesium alloy sample, and in particular to a test device and method for high-temperature shot peening.

Background technique

Fatigue fracture has always been the most important form of damage to mechanical parts and engineering components. In aerospace, shipbuilding, chemical machinery, transportation, engineering machinery and other fields, about 50-90% of structural strength damage is caused by fatigue damage. Magnesium alloy is a metal material with great development potential, and the improvement of fatigue performance is conducive to expanding its application field. As we all know, shot peening is a commonly used method to improve the fatigue strength and fatigue life of metal materials. In recent years, some scientific and technological workers have tried to use shot peening to improve the fatigue performance of magnesium alloys. less difficult. This is mainly related to the crystal structure of magnesium alloys. Most magnesium alloys have a close-packed hexagonal crystal structure. Below 498K, the plasticity of polycrystalline magnesium is limited to the basal plane {0001} slip and Twins, because there are only three geometric slip systems and two independent slip systems when magnesium alloys are deformed, cold plastic deformation is difficult, and the hardness of the matrix is low, and the surface is difficult to withstand severe plastic deformation. Although low-strength shot peening can greatly improve Fatigue performance, but higher strength shot peening will cause surface defects and produce microcracks, so the surface effect of magnesium alloy shot peening that has been reported so far is not ideal. And when it is higher than 498K, the additional slip surface of magnesium alloy and Starting, it is beneficial to deformation, plasticity is improved, and it is easy to form and process. Therefore, if the magnesium alloy is subjected to shot peening treatment under high temperature conditions, that is, high temperature shot peening, its fatigue performance can be improved more effectively.

Find through literature retrieval to prior art, " Optimized warmpeening of the quenched and tempered steel AISI4140 " (2002, 335 phase 198-206 pages) that R.Menig published on " Materials science and engineering A " mentions a kind of high-temperature shot-peening device, and this device adopts furnace chamber and high-temperature gas Mixed heating mode, the maximum temperature is 290 degrees. But this device can't make the sample obtain uniform shot-peening rotating device, it is inconvenient to clamp and unload the sample, and there is no device for measuring the temperature of the sample during the shot-peening process, and the device has a complex structure and a large volume.

Contents of the invention

The present invention aims at the deficiencies in the prior art above, and provides a shot blasting machine capable of performing high-temperature shot peening on alloy shaft samples in a rotating state, so as to improve the uniformity of shot peening on the surface of the samples. According to the device provided by the present invention, the structure is simple, and the alloy shaft sample can be clamped and unloaded conveniently, and the temperature can be measured while the alloy shaft sample is shot peened at high temperature, so that the alloy shaft sample can get the best shot peening effect .

According to one aspect of the present invention, a test device for high-temperature shot peening is provided, including an air compression system, a high-pressure air heating gun, a spray gun, a storage tank, a sample rotating mechanism, a sample holding tool, and a sample temperature measurement system, Among them, the air compression system, high-pressure air heating gun, and spray gun are connected in sequence. The spray gun is placed under the high-pressure air heating gun. The side of the spray gun is connected to the storage tank. The clamping tool is fixed on the sample rotating mechanism, the sample temperature measurement system is connected with the sample clamping tool, and the sample temperature measurement system is used to test the temperature of the sample at any time.

Preferably, the air compression system includes an air compressor, a delivery air pipe, and a circulating water cooler, the air compressor is connected to the circulating water cooler through the delivery air pipe, and the circulating water cooler is connected to the air heating gun.

Preferably, the high-pressure air heating gun is used to heat the high-pressure gas to about 1000 degrees Celsius to form high-temperature and high-pressure gas.

Preferably, the high-pressure air heating gun includes a gun body, an electric heating element and a thermocouple, wherein the gun body is made of stainless steel, an insulating material is used outside the gun body to keep warm, and the electric heating elements are arranged in the gun body for measuring The thermocouple of the temperature of the air outlet is placed at the front end of the gun body.

Preferably, the spray gun is made of stainless steel, and the outside of the spray gun is provided with a thermal insulation jacket for preventing temperature loss.

Preferably, the storage tank is an open cylindrical shape, the material is stainless steel, and the surrounding is heated with a resistance heating ring, and the temperature can be controlled within the range of 500 degrees Celsius. The storage tank is connected to the spray gun through a feeding pipe, and the bottom of the storage tank A discharge valve is installed on the delivery pipe, and the discharge valve is used to adjust the amount of sand discharged according to the shot peening intensity.

Preferably, the sample rotating mechanism includes a rotating motor, a frequency regulator, a platform, and a rotating shaft. The rotating motor is connected to the frequency regulator and fixed on the platform. The rotating motor is connected to the rotating shaft, and the rotating motor is used to drive the sample to rotate at a constant speed.

Preferably, the sample holding tool includes a flat-head set screw, a sample clamp, and a sleeve chuck. The flat-head set screw installed on the sample clamp is used to fix the sample, and the sample clamp is fixed on the sleeve by the flat-head set screw. On the pipe chuck, the casing chuck is fixed on the positioning connecting column of the rotating shaft of the sample rotating mechanism by a pointed positioning screw.

Preferably, the sample temperature measurement system includes a temperature measuring probe, a sensing line and a thermometer, one end of the temperature measuring probe goes deep into the sample held by the sample holding tool, and the other end of the temperature measuring probe passes through the sensor Connect the thermometer to the wire.

According to another aspect of the present invention, also provide a kind of test method of high-temperature shot peening, heat storage tank in advance, make shot peening medium reach required temperature, after the air is pressurized to 1.5 MPa with air compressor again, through After the delivery air pipe enters the high-pressure air heating gun and heats the high-temperature and high-pressure gas at 1000 degrees Celsius, it is sprayed on the sample through the spray gun, and at the same time, the sample rotation mechanism is controlled by the frequency regulator to make the sample rotate at a certain speed. When the sample rises to the predetermined temperature, Open the discharge valve under the storage tank, use the high-temperature and high-pressure air to flow at high speed in the spray gun to form the ejection effect generated by the negative pressure, and spray the shot peening medium to hit the sample to ensure uniform heating and uniform shot peening.

When the present invention is working, pre-heat the storage tank to make the shot blasting medium reach the required temperature, then pressurize the air to above 1.5 MPa, enter the high-pressure air heating gun through the conveying pipeline, and after becoming high-temperature and high-pressure gas, spray it in the air through the spray gun. On the shaft sample, at the same time, turn on the rotary switch to rotate the rotating shaft. When the sample rises to the predetermined temperature, open the discharge valve under the storage tank, and use high-temperature and high-pressure air to flow at high speed in the spray gun to form a negative pressure ejection. The effect is to spray high-temperature pellets and impinge on the magnesium alloy standard shaft sample. Ensure uniform heating and uniform shot peening.

Compared with the prior art, the present invention has the following beneficial effects: the present invention uses high-temperature and high-pressure gas for shot peening, and the maximum shot peening temperature reaches 400 degrees Celsius, which satisfies the additional sliding surface of the magnesium alloy sample and is beneficial to the improvement of the plasticity of the magnesium alloy , Improve the deformation ability and widen the shot peening operation window. The design of the temperature measurement system can measure the temperature of the sample under the condition of rotation, which improves the accuracy of the experiment. The material storage box is located above the spray gun, and can be shot under a small negative pressure, and the minimum shot peening intensity can reach 0.05mmN.

Description of drawings

Other characteristics, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

Fig. 1 is the structural representation of the test device of high temperature shot peening provided according to the present invention;

Fig. 2 is the structural representation of the sample temperature testing system and the sample holding tool in the test device of high temperature shot peening provided according to the present invention;

Fig. 3 is a schematic structural view of the high-pressure air heating gun in the test device for high-temperature shot peening provided by the present invention.

In the figure: 1-sample, 2-flat head positioning screw, 3-sample fixture, 4-casing chuck, 5-temperature measuring probe, 6-small hole, 7-rotating shaft, 8-thermometer, 9 - connecting column, 10 - pointed clamping screw, 11 - high pressure air heating gun, 12 - electric heating element, 13 - gun body, 14 - thermocouple, 15 - resistance heating ring, 16 - rotating motor, 17 - platform, 18-frequency regulator, 19-air compressor, 20-delivery air pipe, 21-spray gun, 22-material delivery pipe, 23-sample rotating mechanism, 24-sample clamping tool, 25-sample temperature measurement system, 26 - Discharging valve, 27 - insulation cover, 28 - circulating water cooler, 29 - storage tank, 30 - sensing line.

detailed description

The embodiments of the present invention are described in detail below in conjunction with the accompanying drawings: this embodiment is implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are provided, but the protection scope of the present invention is not limited to the following the described embodiment.

The embodiment shown in Figure 1 and 2, in the present embodiment, the test device of described high-temperature shot peening comprises air compressor 19, high-pressure air heating gun 11, spray gun 21, storage tank 29, sample rotating mechanism 23 , sample clamping tool 24, sample temperature measurement system 25, air compressor 19 is connected with air pressure valve, and then connected to circulating water cooler 28 through delivery air pipe 20, circulating water cooler 28 and high-pressure air heating gun 11 air inlet The upper end is connected, the air outlet of the high-pressure air heating gun 11 is connected to the spray gun 21, and the side of the spray gun 21 is communicated with the material storage tank 29 through the material delivery pipe 22, and the connection between the material storage tank 29 and the material delivery pipe 22 is provided with a discharge valve 26, The nozzle of the spray gun 21 is aimed at the sample 1, and the sample 1 is clamped by the sample holder 3, and the sample holder 3 is fixed on the rotating shaft 7 through the casing chuck 4. The temperature measuring system 25 is mainly composed of a temperature measuring probe 5, a sensing line 30 and a thermometer 8. The temperature measuring probe 5 is fixed on the axis of the casing chuck 4, and one end of the temperature measuring probe 5 goes deep into the shaft sample 1 Among them, the sensing line 30 connected to the other end of the temperature measuring probe 5 passes through the small hole 6 and is connected to the temperature measuring instrument 8 fixed on the rotating shaft 7 .

As shown in Figure 1, the air compression system includes an air compressor 19, a delivery air pipe 20 and a circulating water cooler 28, and the connection relationship is: the air compressor 19 is connected to the circulating water cooler 28 through the delivery air pipe 20, and the circulating water cooler 28 links to each other with air heating gun 11, and delivery air pipe 20 is pressure-resistant pipe, and circulating water cooler 28 prevents pressure-resistant pipe from scorching.

As shown in Figures 1 and 3, the high-pressure air heating gun 11 includes a gun body 13, an electric heating element 12 and a thermocouple 14, wherein the gun body 13 is made of stainless steel, and an insulating material is used outside to keep warm, and the electric heating element 12 Arranged in the gun body 11, a thermocouple 14 is placed at the front end of the gun body 11 for measuring the gas temperature at the gas outlet.

As shown in FIG. 1 , the spray gun 21 is made of stainless steel, and the outside of the spray gun 21 is provided with a thermal insulation cover 27 to prevent temperature loss.

As shown in Figure 1, described storage tank 29 is the cylindrical shape of opening, and material is stainless steel, is heated with electric resistance heating coil 15 around, can carry out temperature control in the range of 500 degrees Celsius, the feed pipe 22 below storage tank 29 A discharge valve 26 is installed on the top, and the amount of sand discharge can be adjusted according to the shot peening intensity.

As shown in Figure 1, the sample rotating mechanism 24 includes a rotating motor 16, a frequency regulator 18, a platform 17, and a rotating shaft 7. Connected to drive the sample to rotate at a constant speed.

As shown in Figure 2, the sample holding tool 24 includes a sample holder 3, a casing chuck 4, a flat set screw 2, and a pointed clamping screw 10. The connection mode is that the sample holder 3 passes through the flat head The positioning screw 2 is fixed on the casing collet 4, and the casing collet 4 is fixed on the rotating shaft 7 through the pointed clamping screw 10.

As shown in Figure 2, the sample temperature measurement system 25 includes a perforated alloy shaft sample 1, a casing chuck 4, a thermometer 8 and a temperature measuring probe 5, wherein the temperature measuring probe 5 is located in the casing clamp In the center of the head 4, one end of the temperature measuring probe 5 goes deep into the shaft sample 1, and the other end is connected to the sensing line 30, which is connected to the thermometer 8 through a small hole 6, so that the shaft can be tested at any time. The temperature of sample 1.

In a specific embodiment of the present invention, the storage tank 29 is heated in advance to make the shot blasting medium reach the required temperature, and then the air is pressurized to 1.5 MPa with the air compressor 19, and then enters the high-pressure air through the air delivery pipe 20 for heating. Gun 11, the temperature of the high-temperature and high-pressure gas can be heated to 1000 degrees Celsius. After becoming a high-temperature and high-pressure gas, it is sprayed on the alloy shaft sample 1 through the spray gun 21. At the same time, the frequency regulator 18 is turned on to make the rotating shaft 7 rotate at a certain speed. When the test sample 1 rises to a predetermined temperature, the discharge valve 26 under the storage tank 29 is opened, and the high-temperature and high-pressure air flows at a high speed in the spray gun to form the ejection effect caused by the negative pressure, and the sprayed shot blasting medium hits the shaft alloy test sample. On sample 1, ensure uniform heating and uniform shot peening.

Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art may make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims (6)

1. the test unit of a high temperature shot-peening, it is characterized in that, comprise air compression system, pressure-air heating gun, spray gun, storage tank, sample rotating mechanism, sample holder instrument, measuring sample temperature system, wherein, air compression system, pressure-air heating gun, spray gun connects successively, spray gun is placed in below pressure-air heating gun, spray gun side is connected with storage tank, sample clamped by spray tip aligned beneath sample holder instrument, sample holder instrument is fixed on sample rotating mechanism, measuring sample temperature system connects sample holder instrument, measuring sample temperature system is used for the temperature of test sample at any time,

Described storage tank is the cylindrical shape of opening, material is stainless steel, be heated by resistive circle heating around, temperature control can be carried out in 500 degree Celsius range, storage tank connects spray gun by conveying pipeline, conveying pipeline below storage tank is provided with blow-off valve, and blow-off valve is used for according to shot peening strength size adjustment sediment outflow amount;

Described sample rotating mechanism, comprises rotary electric machine, frequency modulator, platform, rotation axis, and rotary electric machine is fixed on platform after connecting frequency modulator, and rotary electric machine is connected with rotation axis, and rotary electric machine at the uniform velocity rotates for driving sample;

Described sample holder instrument comprises tack dog screw, specimen holder, sleeve pipe chuck, be installed on tack dog screw on specimen holder for fixing sample, specimen holder is fixed on sleeve pipe chuck by tack dog screw, and what sleeve pipe chuck was fixed on the rotation axis of sample rotating mechanism by point set screw is located by connecting on post;

Described measuring sample temperature system comprises temperature probe, sense line and temperature measurer, and one end of temperature probe is deep in the middle of sample clamped by sample holder instrument, and the temperature probe other end connects temperature measurer by sense line;

The sense line be connected with the other end of temperature probe is connected with fixing temperature measurer on the rotating shaft through aperture;

Storage tank is positioned at above spray gun.

2. the test unit of high temperature shot-peening according to claim 1, it is characterized in that, described air compression system comprises air compressor, conveying tracheae, recirculated water cooler, and air compressor is connected on recirculated water cooler by conveying tracheae, and recirculated water cooler is connected with heat gun.

3. the test unit of high temperature shot-peening according to claim 1, is characterized in that, described pressure-air heating gun is used for, by the heating temperatures of gases at high pressure to about 1000 degrees Celsius, forming high temperature and high pressure gas.

4. the test unit of high temperature shot-peening according to claim 3, it is characterized in that, described pressure-air heating gun, comprise rifle body, electrical heating elements and thermopair, wherein rifle body is made up of stainless steel, the external face of rifle uses thermal insulation material to be incubated, and electrical heating elements is arranged in rifle body, and the thermopair for the temperature measuring gas port is placed in rifle body front end.

5. the test unit of high temperature shot-peening according to claim 1, is characterized in that, described spray gun is made by for stainless steel material, is provided with the muff for preventing temperature to scatter and disappear outside spray gun.

6. the test method of a high temperature shot-peening, it is characterized in that, heat storage tank in advance, blasting media is made to reach temperature required, again with air compressor by after air pressurized to 1.5 MPas, enter after pressure-air heating gun is heated to be the high temperature and high pressure gas of 1000 degrees Celsius through conveying tracheae, through lance ejection on sample, utilize frequency modulator Control Assay rotating mechanism to make sample by certain rotational speed simultaneously, treat that sample rises to predetermined temperature, open the blow-off valve under storage tank, High Temperature High Pressure air flow at high speed in spray gun is utilized to form the ejector action of negative pressure generation, ejection blasting media strikes on sample, ensure thermally equivalent and even shot-peening,

Described storage tank is the cylindrical shape of opening, material is stainless steel, be heated by resistive circle heating around, temperature control can be carried out in 500 degree Celsius range, storage tank connects spray gun by conveying pipeline, conveying pipeline below storage tank is provided with blow-off valve, and blow-off valve is used for according to shot peening strength size adjustment sediment outflow amount;

Described sample rotating mechanism, comprises rotary electric machine, frequency modulator, platform, rotation axis, and rotary electric machine is fixed on platform after connecting frequency modulator, and rotary electric machine is connected with rotation axis, and rotary electric machine at the uniform velocity rotates for driving sample;

Described sample holder instrument comprises tack dog screw, specimen holder, sleeve pipe chuck, be installed on tack dog screw on specimen holder for fixing sample, specimen holder is fixed on sleeve pipe chuck by tack dog screw, and what sleeve pipe chuck was fixed on the rotation axis of sample rotating mechanism by point set screw is located by connecting on post;

Storage tank is positioned at above spray gun.