[0031] Such as figure 1 As shown, the high temperature and high pressure in-situ scratch and corrosion wear test device of the present invention is provided with: cooling water outlet 1, high temperature work/auxiliary electrode seat 2, liquid phase valve 3, autoclave cover 4, autoclave body 5, heating furnace 6 , Furnace wire 7, bracket 8, auxiliary electrode 9, cemented carbide cutting head 10, working electrode 11, inverter switch 12, heating power switch 13, heating voltage regulator 14, pressure indicator 15, temperature controller 16, inverter 17. Gas phase valve 18, cooling water inlet 19, high temperature reference electrode 20, pressure gauge 21, safety valve 22, manual lift plate 23, pressure sensor 24, inner magnet 25, motor 26, outer magnet 27 and control box 28 The specific structure is as follows:
[0032] The autoclave is composed of an autoclave body 5 and an autoclave cover 4. The autoclave cover 4 is arranged on the autoclave body 5, and the autoclave body 5 and the autoclave cover 4 are connected by bolts. The autoclave cover 4 is provided with a high-temperature working/auxiliary electrode holder 2 and a high-temperature reference electrode 20, and the autoclave body 5 is equipped with an auxiliary electrode 9, a cemented carbide head 10, and a working electrode 11. The auxiliary electrode 9 and the working electrode 11 pass through The wire passes through the high-temperature working/auxiliary electrode holder 2, and the high-temperature reference electrode conduit 35 of the high-temperature reference electrode 20 extends into the autoclave body 5.
[0033] The inner magnet 25 and the outer magnet 27 are arranged inside and outside. The output end of the frequency converter 17 is connected to the motor 26, and the motor 26 is controlled to run through the frequency converter 17. The motor 26 is connected to the outer magnet 27 through the eccentric link mechanism, and the motor 26 drives the eccentric The linkage mechanism moves, so that the outer magnetic steel 27 moves up and down in the axial direction. The outer surface of the inner magnet 25 is welded with a layer of stainless steel to prevent the inner magnet 25 from contacting the gas phase in the autoclave. The lower part of the inner magnet 25 is connected with an up-and-down moving shaft 31, and a cooling water jacket 32 is provided outside the up-and-down moving shaft 31 to move up and down. The shaft 31 is connected in sections, which is easy to disassemble and maintain. One end of the up-and-down movement shaft 31 is threaded to connect the inner magnetic steel 25, and the other end passes through the base 33 in the autoclave body 5. The up-and-down movement shaft 31 is equipped with a cemented carbide cutting head 10, and the sample fixing groove 29 is set on the base 33.
[0034] The invention can adjust the distance between the inner and outer magnetic steel and the stroke of the cutting head by adjusting the distance between the eccentric wheel linkage mechanism and the central shaft of the motor. Both the upper and lower ends of the inner magnetic steel 25 and the outer magnetic steel 27 are provided with ceramic lubrication, and the central hole of the base 33 is equipped with ceramics, which facilitates the lubrication of the lower part of the vertical movement shaft 31 with ceramics. The up and down movement of the hard alloy cutting head 10 is controlled by the magnetic force generated between the inner and outer magnets, and the inner and outer magnets are not in direct contact. The outside of the shaft sleeve 30 of the up and down movement shaft 31 is provided with a cooling water jacket 32, which can effectively prevent the temperature from being too high and the magnet steel from being demagnetized. The outer magnet 27 drives the eccentric to move up and down with the rotation of the motor outside the shaft sleeve 30, and the inner magnet 25 moves up and down inside the shaft sleeve 30 along with the outer magnet 27.
[0035] The autoclave cover 4 is equipped with an autoclave liquid guide tube 34, and the autoclave liquid guide tube 34 is equipped with a liquid phase valve 3. The gas phase port 43 of the autoclave is divided into three ways, connected to the pressure gauge 21, the safety valve 22 and the pressure sensor 24 respectively. , A gas phase valve 18 is provided on the gas phase port 43 of the autoclave.
[0036] The cooling water inlet 19 is connected to the cooling water outlet 1 via the high-temperature reference electrode 20, the cooling water jacket 32 and the high-temperature working/auxiliary electrode holder 2 through the pipeline.
[0037] A heating furnace 6 is provided outside the autoclave body 5, and a furnace wire 7 is provided in the heating furnace 6. The bracket 8 is a double column bracket. The two columns on the bracket 8: column I36 and column II37 are arranged in parallel on both sides of the autoclave cover 4, the autoclave body 5, and the heating furnace 6, and the column I36 is provided with a slider II39 and an autoclave Cover fixing block 40, column II37 is provided with sliding block I38, autoclave cover fixing block 41, motor fixing block 42, sliding block I38 is connected with heating furnace 6, sliding block II39 is connected with autoclave body 5, and autoclave cover fixing block 40 , The autoclave cover fixing block 41 is symmetrically arranged and connected to both sides of the autoclave cover 4. The adjustment mechanism of the nut screw is used between each slider and the column. The top of the column I36 and the column II37 is provided with a manual lift plate 23. The manual lift plate 23 can be adjusted to make the slider I38 and the slider II39 go up and down along the two columns. movement.
[0038] The control box 28 is provided with a frequency converter switch 12, a heating power switch 13, a heating voltage regulator 14, a pressure indicator 15, a temperature controller 16 and a frequency converter 17. The frequency converter switch 12 is connected to the frequency converter 17, and the frequency converter switch 12 is used for To control the opening and closing of the frequency converter 17, the frequency converter 17 is connected to the motor 26 through wires. The movement speed of the cemented carbide scribe head 10 when scratching the surface of the sample 29 can be precisely controlled by the frequency converter; heating power switch 13 and heating voltage regulator 14 Connection, the heating voltage regulator 14 is connected to the temperature controller 16, the pressure indicator 15 and the temperature controller 16 are connected to the internal relay, and the internal relay is connected to the furnace wire 7 through a wire to form an over-temperature power-off heating structure and an over-voltage power-off heating structure . The maximum working temperature of the device of the invention can reach 350°C, and the maximum working pressure can reach 20MPa.
[0039] In the present invention, the function of the high-temperature working/auxiliary electrode holder 2 is to lead the wires in the autoclave through the electrode holder and ensure insulation and sealing. Among them, the high-temperature auxiliary electrode 9 is made of an external platinum wire covered with a PTFE heat shrinkable tube as a wire and spot welded behind the platinum sheet, and the high-temperature working electrode 11 is made of an external one covered with a PTFE heat shrinkable tube. The pure nickel wire or stainless steel wire is made by spot welding on the metal sample as the wire. There are four holes in the high-temperature working/auxiliary electrode holder 2, which can lead the wires on the high-temperature auxiliary electrode and the wires on the high-temperature working electrode at the same time, so it is called the high-temperature working/auxiliary electrode holder. The high temperature reference electrode 20 adopts an Ag/AgCl electrode.
[0040] In the present invention, through the frequency converter 17, the motor 26, the autoclave, the control box 28, the double-pillar fixing bracket 8, the movement shaft, the cemented carbide cutting head 10, etc., it is possible to perform in-situ single-shot on the sample surface under high temperature and high pressure. Research on scratches and multiple reciprocating corrosion and wear, and through the high temperature and high pressure reference electrode installed on the autoclave, high temperature and high pressure work, auxiliary electrode and electrochemical workstation, the surface film of the sample during the scratch or corrosion wear process The signal from the process from destruction to passivation is detected.
[0041] In the present invention, the lead clamps of the working electrode, auxiliary electrode and reference electrode on the electrochemical workstation are connected to the high-temperature working electrode 11 lead, the high-temperature auxiliary electrode 9 lead, and the high-temperature reference electrode 20 lead respectively. By setting the program parameters of the electrochemical workstation in the computer, the signals generated during the corrosion process can be detected.
[0042] Such as figure 2 As shown, a base 33 is provided in the autoclave body 5, and base fixing bolt holes 46 are opened on the base 33. The bolts fix the base 33 on the autoclave cover 4 through the base fixing bolt holes 46 ( figure 1 ). The back of the cemented carbide scribe head 10 is provided with a spring 47, and the contact normal stress between the cemented carbide scribe head 10 and the sample 44 can be adjusted by the spring 47. A scribe head fixing bolt 45 is provided on the side of the cemented carbide scribe head 10, The distance between the cemented carbide scribe head 10 and the sample 44 can be fixed by the scribe head fixing bolt 45 to control the strength of the cemented carbide scribe head 10 when scribing across the surface of the sample 44, and ensure that the cemented carbide scribe head 10 The pressure is constant when tracing the surface of the sample 44. The sample 44 with a size of 10mm×10mm×2mm is fixed in the sample fixing groove 29 (dovetail groove). A sample fastening bolt 49 is provided on the sample fixing groove 29 on the back of the sample 44, and the cemented carbide is moved up and down The scribe head 10 is used to scratch the surface of the sample 44, and the cemented carbide scribe head 10 can be made of cemented carbide YG8, aluminum oxide or diamond. A polytetrafluoroethylene tank 48 or a Zr4 alloy tank with an oxide film on the surface is arranged between the sample 44 and the sample fixing groove 29, and the sample 44 and the device for fixing the sample are insulated.
[0043] The working process of the high temperature and high pressure in-situ scratch and corrosion wear test device of the present invention is as follows:
[0044] 1. Cover the outer surface of pure nickel wire or stainless steel wire with a layer of PTFE heat-shrinkable tube, heat-shrink it with a heat gun, and weld it on the surface of the sample as a wire;
[0045] 2. Install the sample in the sample fixing groove with PTFE, and tighten the bolt on the back of the sample;
[0046] 3. Install the auxiliary electrode in the autoclave and keep it directly opposite to the sample;
[0047] 4. Install the high temperature reference electrode in the autoclave and keep the liquid outlet on the upper part of the high temperature reference electrode open;
[0048] 5. Set the inverter parameters, adjust the distance between the scribe head and the sample and the spring on the back of the scribe head to ensure that the scribe head can contact the sample during the sliding process and will not touch the auxiliary electrode;
[0049] 6. Add a solution with a volume of 1/2 to 2/3 of the autoclave volume into the autoclave. The solution can be selected according to the actual working environment, such as an aqueous solution containing boric acid and lithium hydroxide in the primary loop of a nuclear power plant, and ensure that the sample, The lower end of the auxiliary electrode and the high temperature reference electrode catheter 35 can be completely immersed in the solution;
[0050] 7. Adjust the manual lifting plate, adjust the autoclave body and the heating furnace to an appropriate height in turn, and tighten the bolts on the autoclave cover;
[0051] 8. According to the needs of the experiment, pass nitrogen into the autoclave to remove oxygen from the liquid phase port of the autoclave, and then discharge it from the gas phase valve. After degassing, close the liquid phase valve and the gas phase valve in sequence;
[0052] 9. Set the target temperature on the temperature controller, the upper limit of the temperature for automatic power-off over temperature, the heating regulation voltage, and the upper limit of the pressure for automatic power-off over pressure;
[0053] 10. Turn on the cooling water switch and pour cooling water into the cooling water inlet;
[0054] 11. Turn on the heating power switch, and after the high temperature reference electrode has continuous water outlet, tighten the valve at the outlet to close;
[0055] 12. Research on repassivation behavior and corrosion and wear behavior
[0056] ①Re-passivation behavior study: After the temperature reaches the set value and becomes stable, use a potentiostat to add a constant potential to the sample according to the test needs to make it in a passivated state. After stabilizing for 30 minutes, turn on the switch of the inverter to make the scribe head across the surface of the sample, the surface passivation film is damaged, and a new passivation film is quickly formed. Turn off the inverter switch after a single scratch is completed. Through the electrochemical workstation to quickly collect and record the current changes caused during the process, the repassivation ability of the material can be known.
[0057] ②Study on corrosion and wear behavior: After the temperature reaches the set value and becomes stable, use a potentiostat to add a constant potential to the sample according to the test needs to make it in a passivated state. After stabilizing for 30 minutes, turn on the switch of the inverter to make the scribe head reciprocate across the surface of the sample, and the surface passivation film will be repeatedly damaged and repassivated. Through the electrochemical workstation to quickly collect and record the current changes caused during the process, the corrosion and wear information related to the process can be learned.
