High-throughput detection method for corrosion resistance of metal

Abstract

The invention relates to the technical field of corrosion electrochemistry, and discloses a high-throughput detection method for corrosion resistance of metal. A distributed multi-channel electrochemical workstation comprises an independent multi-channel direct-current test electrochemical workstation and an independent multi-channel alternating-current test electrochemical workstation, the high-throughput detection method for the corrosion resistance of the metal comprises the step of detecting the corrosion resistance of the metal by using the distributed multi-channel electrochemical workstation. The distributed multi-channel electrochemical workstation provided by the invention can effectively avoid the galvanic corrosion phenomenon caused by a wire beam electrode electrochemical corrosion experiment and the problems of high cost and large occupied space of a traditional independent parallel high-flux electrochemical corrosion experiment; the high-throughput detection method for the corrosion resistance of the metal, provided by the invention, not only can ensure the detection efficiency, but also greatly reduces the test cost, and can be suitable for high-throughput electrochemical corrosion experiment tests of different metal materials.

Description

Technical Field

[0001] The invention relates to the field of corrosion electrochemical technology, and in particular to a high-throughput detection method for metal corrosion resistance. Background Art

[0002] In the marine environment, affected by factors such as salt spray, humidity, and temperature, metal materials are very likely to undergo electrochemical corrosion reactions due to surface wetting or direct immersion, which seriously affects the working performance and service life of marine engineering equipment. The research objects of existing corrosion characterization technologies are usually single samples and single solution systems. The tests are time-consuming and cannot meet the ever-changing needs of new material development and characterization.

[0003] High-throughput experiment refers to an experimental method that completes the preparation or characterization of a large number of samples in a short period of time. The key lies in the parallel preparation or characterization of multiple samples, so as to complete the comprehensive processing of experimental data of multiple materials at the same time. At present, the high-throughput corrosion resistance characterization methods of multiple materials mainly include Wire Beam Electrode High-throughput Experiment (WBEHE) and Independent Parallel High-throughput Experiment (IPHE).

[0004] Wire beam electrode technology refers to preparing samples of different components into array microelectrodes, and obtaining the local corrosion distribution characteristics and non-uniform electrochemical dissolution process of metal surfaces of different components by cyclically scanning the potential and current distribution on the surface of the wire beam electrode. Wire beam electrode technology is widely used in high-throughput corrosion resistance screening, but the wire beam electrode is small in size (1-3mm), cumbersome to prepare and has high measurement accuracy. At the same time, due to the shared solution system, the test results of the wire beam electrode cannot effectively avoid the problem of galvanic corrosion, which leads to certain errors in the screening results.

[0005] Independent parallel experiments refer to increasing the number of channels of an electrochemical workstation and setting each working electrode to independent environmental parameter conditions and electrochemical test conditions, which can achieve high-throughput in-situ electrochemical testing of different metal materials. However, traditional independent parallel high-throughput experiments require a large number of electrochemical workstations, occupy a large space, and are expensive. Summary of the invention

[0006] The present invention aims to solve at least one of the above-mentioned technical problems existing in the prior art. To this end, one of the purposes of the present invention is to provide a distributed multi-channel electrochemical workstation; the second purpose of the present invention is to provide a high-throughput detection method for metal corrosion resistance.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A first aspect of the present invention provides a distributed multi-channel electrochemical workstation, which includes an independent multi-channel direct current test electrochemical workstation and an independent multi-channel alternating current test electrochemical workstation.

[0009] Preferably, the number of channels of the multi-channel DC test electrochemical workstation and the multi-channel AC test electrochemical workstation is determined by enumeration method or intelligent optimization algorithm;

[0010] The objective function expression for determining the number of channels is: Z = αT + βC;

[0011] The objective function satisfies the following constraints:

[0012] (1)T DC =m*t DC / x;

[0013] (2)T AC =m*t AC / y;

[0014] (3)T=max(T DC , T AC );

[0015] (4) C = p*x + q*y;

[0016] Where: m is the number of working electrodes to be tested, pieces;

[0017] x is the number of channels of the multi-channel DC test electrochemical workstation;

[0018] y is the number of channels of the multi-channel AC test electrochemical workstation;

[0019] t DC Time consumed for DC test for each working electrode, min;

[0020] t AC Time consumed for AC test of each working electrode, min;

[0021] T DC is the total DC test time of m working electrodes, min;

[0022] T AC is the total AC test time of m working electrodes, min;

[0023] T is the total test time of electrochemical experiment for m working electrodes, min;

[0024] p is the cost per channel of a multi-channel DC test electrochemical workstation, 10,000 yuan;

[0025] q is the cost per channel of the multi-channel AC test electrochemical workstation, 10,000 yuan;

[0026] C is the total cost of the electrochemical workstation, ten thousand yuan;

[0027] Z is the weighted sum; α and β are weight coefficients.

[0028] Preferably, divided by working areas, the distributed multi-channel electrochemical workstation includes a waiting area I, a DC test waiting area, a DC test area, an AC test waiting area and an AC test area which are connected in sequence.

[0029] Preferably, the waiting area I is used to load the working electrode into the electrolytic cell and add electrolyte solution.

[0030] Preferably, the DC test waiting area is used to store the working electrodes to be tested that have passed through the waiting area I, and the working electrodes that have completed the AC test.

[0031] Preferably, the DC test area is used to perform a DC test on the working electrode.

[0032] Preferably, the AC test area is used to perform an AC test on the working electrode.

[0033] Preferably, the AC test waiting area is used to store working electrodes that have completed DC testing.

[0034] The second aspect of the present invention provides a high-throughput detection method for metal corrosion resistance, comprising the following steps: using the distributed multi-channel electrochemical workstation described in the first aspect of the present invention to perform metal corrosion resistance detection.

[0035] Preferably, in the distributed multi-channel electrochemical workstation, the multi-channel direct current test electrochemical workstation performs a linear polarization test.

[0036] Preferably, in the distributed multi-channel electrochemical workstation, the multi-channel AC test electrochemical workstation performs AC impedance testing.

[0037] Preferably, the parameter settings of the multi-channel DC test electrochemical workstation include test potential, scan rate and DC test time for each working electrode.

[0038] Preferably, the test potential is ±20 mV vs OC; further preferably, the test potential is ±10 mV vs OC.

[0039] Preferably, the scanning rate is 0.1-0.5 mV / s; further preferably, the scanning rate is 0.1-0.3 mV / s.

[0040] Preferably, the DC test of each working electrode takes 2-5 minutes; further preferably, the DC test of each working electrode takes 2-3 minutes.

[0041] Preferably, the parameter settings of the multi-channel AC test electrochemical workstation include the sweep frequency range, amplitude and AC test time of each working electrode.

[0042] Preferably, the frequency sweep range is 0.01-100000 Hz.

[0043] Preferably, the amplitude is 8-12 mV; further preferably, the amplitude is 9-10 mV.

[0044] Preferably, each working electrode AC test takes 15-20 minutes; further preferably, each working electrode AC test takes 16-18 minutes.

[0045] Preferably, the method specifically comprises the following steps: grouping the working electrodes to be tested, and making the working electrodes of different groups enter different workstations synchronously for testing according to the maximum capacity of the multi-channel DC test electrochemical workstation and the multi-channel AC test electrochemical workstation.

[0046] Preferably, the expression for the grouping of the working electrodes to be tested is:

[0047] n = min(x, y);

[0048] f = ROUNDUP [ m / min ( x , y ) ] ;

[0049] Where: n is the number of working electrodes in each group, pieces;

[0050] f is the number of groups, groups;

[0051] ROUNDUP means round up function;

[0052] m is the number of working electrodes to be tested, pieces;

[0053] x is the number of channels of the multi-channel DC test electrochemical workstation;

[0054] y is the number of channels of the multi-channel AC test electrochemical workstation.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] 1) Compared with the traditional multi-channel electrochemical workstation, the distributed multi-channel electrochemical workstation provided by the present invention splits the DC test function and the AC test function to form a multi-channel DC test electrochemical workstation and a multi-channel AC test electrochemical workstation. The working electrodes perform DC test and AC test in turn, which can effectively avoid the galvanic corrosion phenomenon caused by the wire beam electrode electrochemical corrosion experiment, as well as the problems of high cost and large space occupied by the traditional independent parallel high-throughput electrochemical corrosion experiment;

[0057] 2) The high-throughput detection method for metal corrosion resistance provided by the present invention can not only ensure detection efficiency but also greatly reduce testing costs, and can be applied to high-throughput electrochemical corrosion experimental tests of different metal materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 This is a schematic diagram of a traditional multi-channel electrochemical workstation;

[0059] Figure 2 This is a schematic diagram of a distributed multi-channel electrochemical workstation in Example 1;

[0060] Figure 3 This is a schematic diagram of the working status of each area of ​​the 0-2.5min distributed multi-channel electrochemical workstation in Example 1;

[0061] Figure 4 This is a schematic diagram of the working status of each area of ​​the 2.5-5min distributed multi-channel electrochemical workstation in Example 1;

[0062] Figure 5 The linear polarization data of the DC test in Example 1;

[0063] Figure 6 This is the AC impedance data of the AC test in Example 1. DETAILED DESCRIPTION

[0064] The present invention is further described in detail below by specific examples. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial sources or can be obtained by prior art methods. Unless otherwise specified, the experiments or test methods are conventional methods in the art.

[0065] In the following embodiments and comparative examples, the working electrodes to be tested are carbon steel working electrodes, the number of which is 96. The working electrodes are resin encapsulated, polished and ultrasonically cleaned, and the exposed surface is 1cm*1cm. The test conditions are: 3.5% NaCl solution, saturated calomel reference electrode, and platinum counter electrode.

[0066] Example 1

[0067] This example performs high-throughput testing on the corrosion resistance of the carbon steel working electrode. Figure 1 This is a schematic diagram of a traditional multi-channel electrochemical workstation. Each channel has DC test and AC test functions, which are independent and do not interfere with each other. Figure 2 Schematic diagram of a distributed multi-channel electrochemical workstation in Example 1, which includes independent multi-channel direct current test electrochemical workstations ( Figure 2 (a)) and multi-channel AC test electrochemical workstation ( Figure 2 (b)).

[0068] In the distributed multi-channel electrochemical workstation, the multi-channel DC test electrochemical workstation performed linear polarization test, set the test potential to ±20mV vs OC, the scan rate to 0.1667mV / s, and the test time to 2.5min / working electrode; the multi-channel AC test electrochemical workstation performed AC impedance test, set the sweep frequency range to 100000Hz to 0.01Hz, the amplitude to 10mV, and the test time to 17min / working electrode.

[0069] The cost of a multi-channel DC test electrochemical workstation is 20,000 yuan / channel, and the cost of a multi-channel AC test electrochemical workstation is 20,000 yuan / channel. The objective function expression of the number of channels is: Z = αT + βC, and the constraints are:

[0070] (1) Total DC test time (min): T DC =96*2.5 / x;

[0071] (2) Total AC test time (min): T AC =96*17 / y;

[0072] (3) Total time of electrochemical test (min): T = max (T DC , T AC );

[0073] (4) Total cost of electrochemical workstation (10,000 yuan): C = 2*x + 2*y;

[0074] The weight coefficient α=β=1 is set, that is, cost and efficiency are comprehensively considered, then the objective function is Z=T+C, and the optimal number of channels x=4 for a multi-channel DC test electrochemical workstation and the number of channels y=24 for a multi-channel AC test electrochemical workstation are obtained by enumeration method.

[0075] That is, the total DC test time for 96 carbon steel working electrodes is 60 minutes, the total AC test time is 68 minutes, the total electrochemical experimental test time is 68 minutes, and the total cost of the electrochemical workstation is 560,000 yuan.

[0076] The specific test process is: 96 carbon steel working electrodes are grouped, and the expression is:

[0077] n=min(4,24), f=ROUNDUP[96 / (4,24)], that is, the 96 working electrodes are divided into 24 groups of 4 and numbered as ax.

[0078] The distributed multi-channel electrochemical workstation is divided into five areas: DC test area, AC test area, waiting area I, DC test waiting area and AC test waiting area. The DC test area performs linear polarization test, about 2.5 min / group, and one group of tests are performed each time. The AC test area performs AC impedance test, about 17 min / group, and 6 groups of tests are performed simultaneously each time; waiting area I is used to load the working electrode into the electrolytic cell and add electrolyte solution, about 2.5 min / group, and one group is performed each time; the DC test waiting area is used to store new working electrodes that have passed through waiting area I, as well as working electrodes that have completed AC tests; the AC test waiting area is used to store working electrodes that have completed DC tests; the test numbers of each period and each area are shown in Table 1.

[0079] The specific test process is described as follows:

[0080] 0-2.5min: Working electrode group a undergoes DC test, groups bg undergo AC test simultaneously, group i enters waiting area Ⅰ to load cells and add electrolyte, group h enters DC test waiting area to queue for DC test, Figure 3 This is a schematic diagram of the working status of each area of ​​the 0-2.5min distributed multi-channel electrochemical workstation in Example 1;

[0081] 2.5-5min: Working electrode group h undergoes DC test, groups bg undergo AC test simultaneously, group j enters waiting area Ⅰ to load cells and add electrolyte, group i enters DC test waiting area to queue for DC test, group a enters AC test waiting area to queue for AC test, Figure 4 This is a schematic diagram of the working status of each area of ​​the 2.5-5min distributed multi-channel electrochemical workstation in Example 1;

[0082] This cycle is repeated to complete the corrosion resistance test of 96 carbon steel working electrodes corresponding to the test numbers of each period and area in Table 1, and the test data are obtained, among which, Figure 5 is the linear polarization data of the DC test in Example 1, Figure 6 This is the AC impedance data of the AC test in Example 1.

[0083] Table 1 Test number of each area in each period of the distributed multi-channel electrochemical workstation in Example 1

[0084]

[0085] Comparative Example 1

[0086] The wire beam electrode technology was used to test the corrosion resistance of 96 working electrodes using a 1-channel array electrode electrochemical scanning system.

[0087] Comparative Example 2

[0088] The traditional independent parallel high-throughput experimental method was used to test the corrosion resistance of 96 working electrodes using a 96-channel full-function electrochemical workstation.

[0089] Table 2 is a comparison of the three high-throughput electrochemical corrosion experimental methods in Example 1 and Comparative Examples 1 and 2. It can be seen from Table 2 that in Example 1, the distributed multi-channel electrochemical workstation and the high-throughput detection method for metal corrosion resistance provided by the present invention are used to test the corrosion resistance of 96 working electrodes, and the DC test and AC test are performed using independent multi-channel DC test electrochemical workstations and multi-channel AC test electrochemical workstations. The total test time is 68 minutes, the test flux is 84.7 / h, and the construction cost of the electrochemical workstation is 560,000. Yuan; in Comparative Example 1, traditional wire beam electrode technology is adopted, and a 1-channel array electrode electrochemical scanning system is adopted. The cost of the electrochemical workstation is low, only 40,000 yuan, but the total test time is 1634.5 minutes, which is inefficient, and because a set of solution systems are shared, the test results of the wire beam electrode cannot effectively avoid the problem of galvanic corrosion; in Comparative Example 2, the traditional independent parallel high-throughput experimental method is adopted, and a 96-channel full-function electrochemical workstation is used, which can complete the test in 19.5 minutes, but the cost of the electrochemical workstation is as high as 3.84 million yuan, which is expensive and occupies a large area.

[0090] Table 2 Comparison of three high-throughput electrochemical corrosion experimental methods in Example 1 and Comparative Examples 1 and 2

[0091]

[0092] The distributed multi-channel electrochemical workstation and high-throughput detection method for metal corrosion resistance provided by the present invention greatly shorten the detection time compared with the traditional wire beam electrode technology, and overcome the galvanic corrosion problem, and the cost investment is within an acceptable range; compared with the traditional independent parallel high-throughput experimental method, the cost and space of the electrochemical workstation are greatly reduced, and the increase in detection time is also within an acceptable range. That is, considering the detection efficiency and cost comprehensively, the practicality of the distributed multi-channel electrochemical workstation and high-throughput detection method for metal corrosion resistance provided by the present invention is much higher than the traditional wire beam electrode technology and the independent parallel high-throughput experimental method, and can be applied to high-throughput electrochemical corrosion experimental testing of different metal materials, better meeting the development and characterization needs of new materials.

Claims

1. A distributed multi-channel electrochemical workstation, characterized in that: The distributed multi-channel electrochemical workstation includes an independent multi-channel direct current test electrochemical workstation and an independent multi-channel alternating current test electrochemical workstation.

2. The distributed multi-channel electrochemical workstation according to claim 1, characterized in that: The number of channels of the multi-channel direct current test electrochemical workstation and the multi-channel alternating current test electrochemical workstation is determined by enumeration method or intelligent optimization algorithm; The objective function expression for determining the number of channels is: Z = αT + βC; The objective function satisfies the following constraints: (1)T DC =m*t DC / x; (2)T AC =m*t AC / y; (3)T=max(T DC ,T AC ); (4) C = p*x + q*y; Where: m is the number of working electrodes to be tested, pieces; x is the number of channels of the multi-channel DC test electrochemical workstation; y is the number of channels of the multi-channel AC test electrochemical workstation; t DC Time consumed for DC test for each working electrode, min; t AC Time consumed for AC test of each working electrode, min; T DC is the total DC test time of m working electrodes, min; T AC is the total AC test time of m working electrodes, min; T is the total test time of electrochemical experiment for m working electrodes, min; p is the cost per channel of a multi-channel DC test electrochemical workstation, 10,000 yuan; q is the cost per channel of the multi-channel AC test electrochemical workstation, 10,000 yuan; C is the total cost of the electrochemical workstation, ten thousand yuan; Z is the weighted sum; α and β are weight coefficients.

3. The distributed multi-channel electrochemical workstation according to claim 1 or 2, characterized in that: According to the working area, the distributed multi-channel electrochemical workstation includes a waiting area I, a DC test waiting area, a DC test area, an AC test waiting area and an AC test area which are connected in sequence.

4. A high-throughput detection method for metal corrosion resistance, characterized in that: The method comprises the following steps: using the distributed multi-channel electrochemical workstation described in claim 3 to test the corrosion resistance of metals.

5. The high-throughput detection method according to claim 4, characterized in that: In the distributed multi-channel electrochemical workstation, the multi-channel direct current test electrochemical workstation performs a linear polarization test.

6. The high-throughput detection method according to claim 4, characterized in that: In the distributed multi-channel electrochemical workstation, the multi-channel AC test electrochemical workstation performs AC impedance testing.

7. The high-throughput detection method according to claim 5, characterized in that: The multi-channel direct current test electrochemical workstation parameter settings include test potential, scan rate and direct current test time of each working electrode; Preferably, the test potential is ±20mVvs OC; Preferably, the scanning rate is 0.1-0.5 mV / s; Preferably, the DC test of each working electrode takes 2-5 minutes.

8. The high-throughput detection method according to claim 6, characterized in that: The multi-channel AC test electrochemical workstation parameter settings include sweep frequency range, amplitude and AC test time for each working electrode; Preferably, the sweep frequency range is 0.01-100000 Hz; Preferably, the amplitude is 8-12 mV; Preferably, each working electrode AC test takes 15-20 minutes.

9. The high-throughput detection method according to any one of claims 4 to 8, characterized in that: The method specifically comprises the following steps: grouping the working electrodes to be tested, and making the working electrodes of different groups enter different workstations synchronously for testing according to the maximum capacity of the multi-channel direct current test electrochemical workstation and the multi-channel alternating current test electrochemical workstation.

10. The high-throughput detection method according to claim 9, characterized in that: The expression for the grouping of the working electrodes to be tested is: n = min(x, y); f = ROUNDUP [ m / min ( x , y ) ] ; Where: n is the number of working electrodes in each group, pieces; f is the number of groups, groups; ROUNDUP means round up function; m is the number of working electrodes to be tested, pieces; x is the number of channels of the multi-channel DC test electrochemical workstation; y is the number of channels of the multi-channel AC test electrochemical workstation.

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