A method for detecting the adhesion degree of a plunger coating layer and a method for evaluating its advantages and disadvantages

Abstract

The present invention provides a method for detecting the adhesion degree of a plunger coating layer and a method for evaluating its advantages and disadvantages. The detection method includes the following steps: Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen; Step 2: Conduct a tensile test on the specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively; Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into the formula K = F1 / F2 to obtain the adhesion coefficient K. The beneficial effects of the present invention are as follows: In the prior art, the static detection method using manual operation is mostly used to judge the adhesion degree of the coating layer. Such methods are time-consuming and laborious, and it is impossible to judge the advantages and disadvantages of the coating layers with little difference in adhesion degree. However, in the present invention, the test equipment is first used for detection, and then the data is brought into the formula for calculation, which is time-saving and labor-saving, reduces the operation intensity of the detection personnel, and quantifies the evaluation of the adhesion degree of the coating layer.

Description

Technical Field

[0001] The present invention relates to the technical field of coating layers, and in particular, to a method for detecting the adhesion degree of a plunger coating layer and a method for evaluating its advantages and disadvantages. Background Art

[0002] At present, the detection of coating layers mostly adopts static detection methods. It mainly detects according to the 14 experimental methods described in GB / T 5270-2005 "Review of Test Methods for Adhesion Strength of Electrodeposited and Chemically Deposited Coatings on Metal Substrates", such as the friction polishing test and the steel ball friction polishing test. These two test methods are only applicable to relatively thin deposited layers and both use the observation method to judge; for another example, the sawing test, file test, chisel test, deep drawing test, and thermal shock test can only use the observation method to judge and cannot perform quantitative analysis; for another example, in the bending test, due to the plastic fluidity of the coating layer, the coating layer is still not damaged when the base metal fractures, and the test results are affected by the base material, heat treatment method, and the size of the specimen, resulting in large data errors.

[0003] Overall, the current existing technologies mainly adopt manual operations, which are time-consuming and laborious, and the detection efficiency is low. Due to the different operating forces of the operators, the errors are relatively large. In particular, the existing detection methods cannot distinguish the advantages and disadvantages of some coating layers with better coating effects, let alone perform quantitative evaluation on them. Summary of the Invention

[0004] To solve the deficiencies of the existing technologies, the present invention provides a method for detecting the adhesion degree of a plunger coating layer and a method for evaluating its advantages and disadvantages.

[0005] The technical solution adopted by the present invention to solve its technical problems is: a method for detecting the adhesion degree of a plunger coating layer, and the detection method includes the following steps:

[0006] Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen;

[0007] Step 2: Conduct a tensile experiment on the specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively;

[0008] Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K,

[0009] K = F1 / F2 (1).

[0010] Preferably, a method for detecting the adhesion degree of a plunger coating layer evaluates the adhesion degree of the coating layer of the plunger plasma spraying process.

[0011] Preferably, a method for detecting the adhesion degree of a plunger coating layer evaluates the adhesion degree of the coating layer in the plunger plasma surfacing process.

[0012] Preferably, a method for detecting the adhesion degree of a plunger coating layer evaluates the adhesion degree of the coating layer in the plunger spray welding and remelting process.

[0013] Preferably, a method for detecting the adhesion degree of a plunger coating layer evaluates the adhesion degree of the coating layer in the plunger amorphous alloy process.

[0014] Preferably, a method for evaluating the quality of the adhesion degree of a plunger coating layer includes the following steps:

[0015] Step 1: Obtain several groups of plungers, and detect the adhesion coefficients of each group of plungers;

[0016] Step 2: Sort the adhesion coefficients of each group of plungers. The larger the adhesion coefficient K, the better the adhesion degree of the corresponding plunger coating layer.

[0017] Preferably, the method for detecting the adhesion coefficient in step 1 of the method for evaluating the quality of the adhesion degree of a plunger coating layer specifically includes the following steps:

[0018] Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen;

[0019] Step 2: Conduct a tensile test on the specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively;

[0020] Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in step 2 into formula (1) to obtain the adhesion coefficient K,

[0021] K = F1 / F2 (1).

[0022] When the present invention is actually used:

[0023] Prepare the specimen: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, take one of them as the specimen, and cut the middle position of the plunger into a dumbbell shape, as shown in Figure 3 .

[0024] Test: Detect the stress F1 when cracks occur in the coating layer and the yield stress F2 of the plunger through a tensile testing machine, and then substitute the two into formula (1) for calculation.

[0025] The beneficial effects of the present invention are:

[0026] In the prior art, the static detection method of manual operation is mostly used to judge the adhesion degree of the coating layer. Such methods are time-consuming and laborious, and it is impossible to judge the advantages and disadvantages of the coating layers with little difference in adhesion degree. However, in the present invention, the test equipment is first used for detection, and then the data is brought into the formula for calculation, which saves time and effort, reduces the operation intensity of the detection personnel, and quantifies the evaluation of the adhesion degree of the coating layer.

[0027] In the static detection method, due to the different operation forces of the detection personnel, the test results have large errors. In the present invention, the data is quantified, and compared with the appearance detection, the detection method of the present invention is more accurate and reliable.

[0028] For multiple specimens with relatively good adhesion of the coating layer, the prior art cannot judge the differences between them, while the detection method disclosed in the present invention can detect the differences of the specimens with relatively good adhesion degree of the coating layer.

[0029] The formula (1) disclosed in the present invention provides a basic support for the applied research of the plunger. The adhesion degree of the plunger coating layer is quantified to obtain an evaluation value, and then the evaluation value is input into the plunger service life prediction system to establish a test and evaluation system for the anti-corrosion and wear-resistant performance of the plunger of the oilfield injection pump, so as to provide a recommended suitable plunger for the reciprocating injection pump and realize the cost reduction and efficiency increase of the operation of the oilfield water injection system.

[0030] The formula (1) disclosed in the present invention provides data support for the research of the plunger. Through the deep learning of the system neural network, the data correlation of the two input layers of product performance and service conditions is processed layer by layer in turn, and the connection weight matrix between neurons is established, so as to realize the prediction of the plunger service life and provide a basis for the test and evaluation system of the anti-corrosion and wear-resistant performance of the plunger of the oilfield injection pump. Description of the Drawings

[0031] Figure 1 It is the failure time of the plunger coating layer with different coating processes in Experiment 1.

[0032] Figure 2 It is the adhesion coefficient of the plunger coating layer with different coating processes in Experiment 1.

[0033] Figure 3 It is the structural schematic diagram of the tensile specimen in the embodiment. Detailed Embodiments

[0034] To clearly illustrate the technical features of this solution, the following is an elaboration of this solution through specific embodiments.

[0035] Embodiment 1:

[0036] This embodiment provides a method for detecting the adhesion degree of the plunger coating layer, and this detection method includes the following steps:

[0037] Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen (as Figure 3 shown);

[0038] Step 2: Conduct a tensile test on the specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively;

[0039] Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K,

[0040] K = F1 / F2 (1).

[0041] Example 2:

[0042] This example provides a method for evaluating the adhesion degree of the plunger coating layer. The evaluation method includes the following steps:

[0043] Step 1: Obtain several plungers to be tested, longitudinally divide each plunger into two halves, and take one of them as the specimen (as Figure 3 shown);

[0044] Step 2: Conduct a tensile test on each specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively;

[0045] Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K,

[0046] K = F1 / F2 (1).

[0047] Step 4: Sort the adhesion coefficients of each plunger. The larger the adhesion coefficient K, the better the adhesion degree of the corresponding plunger coating layer.

[0048] Example 3:

[0049] This example provides a method for evaluating the adhesion degree of the plunger coating layer. The detection method includes the following steps:

[0050] Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen (as Figure 3 shown);

[0051] Step 2: Conduct a tensile test on the specimen, measure the tensile stress and yield stress of the specimen when cracks occur in the coating layer, and record them as F1 and F2 respectively;

[0052] Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K,

[0053] K=F1 / F2 (1).

[0054] Step 4: Use the adhesion coefficient K to evaluate the degree of adhesion of the coating layer by plunger plasma spraying, plasma cladding or spray welding remelting process.

[0055] Comparative Example 1:

[0056] Thermal shock experiment.

[0057] Comparative Example 2:

[0058] Saw sharpening experiment.

[0059] Comparative Example 3:

[0060] Field application experiment.

[0061] The plunger was tested using Example 1 and Comparative Examples 1-3, and the degree of adhesion of the plunger coating layer was evaluated using the method of Example 2.

[0062] Experiment 1:

[0063] ① The plungers were coated by plasma spraying, plasma surfacing and spray welding remelting processes respectively, and 20 plungers were sprayed by each process.

[0064] ② Five plungers of each coating process were selected for thermal shock test, sawing test, field application test and coating adhesion evaluation test disclosed in this patent. The specific results are shown in Table 1 and the attached drawings of the specification.

[0065] Table 1

[0066]

[0067] It can be seen from Table 1 that the performance of the three coating processes is very good. The difference in the adhesion degree of the coating layer cannot be detected through the thermal shock test and the grinding saw test, but from the comparison of the failure time of the plunger coating and the adhesion coefficient, it can be seen that the adhesion coefficient is directly proportional to the failure time of the plunger coating coated with different processes; through the method for evaluating the adhesion degree of the plunger coating disclosed in this patent, it can be judged that the spray welding and remelting process has the best coating effect, followed by plasma surfacing, and plasma spraying has the worst effect. The evaluation result corresponds to the failure time of the plunger coating.

[0068] Experiment 2:

[0069] ① Three batches of 10 plungers of poor quality prepared by plasma spraying process were selected, marked as 1#, 2# and 3#, and subjected to the coating adhesion evaluation test and grinding saw test disclosed in this patent. The experimental results are shown in Table 2.

[0070] Table 2

[0071]

[0072] As can be seen from the saw grinding test in Table 2, the quality of these three batches of plungers is relatively poor, with No. 3 being the worst, No. 2 being the second worst, and No. 1 being the best. Moreover, the adhesion coefficients of these three batches of plungers also correspond to the test results of the saw grinding test. Additionally, the conclusion obtained through the evaluation method for the quality of the plunger coating layer adhesion in Example 2 corresponds to the test results of the saw grinding test.

[0073] Combining Table 1 and Table 2, it can be seen that the method using the adhesion coefficient of the coating layer disclosed in this patent to evaluate the quality of the coating layer adhesion is completely consistent with the test conclusions of the prior art.

Claims

1. A method for detecting the adhesion degree of a plunger coating layer, characterized in that, The detection method includes the following steps: Step 1: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen; Step 2: Conduct a tensile test on the specimen, measure the tensile stress and yield stress when cracks occur in the coating layer of the specimen, and record them as F1 and F2 respectively; Step 3: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K, K = F1 / F2 (1).

2. The method according to claim 1, wherein The method evaluates the adhesion degree of the coating layer of the plunger plasma spraying process.

3. The method according to claim 1, characterized in that, The method evaluates the adhesion degree of the coating layer of the plunger plasma surfacing process.

4. The method according to claim 1, characterized in that The method evaluates the adhesion degree of the coating layer of the plunger spray welding and remelting process.

5. The method according to claim 1, characterized in that, The method evaluates the adhesion degree of the coating layer of the plunger amorphous alloy process.

6. A method for evaluating the quality of the adhesion degree of a plunger coating layer, characterized in that, The evaluation method includes the following steps: Step 1: Obtain several groups of plungers and detect the adhesion coefficient of each group of plungers; Step 2: Sort the adhesion coefficients of each group of plungers. The larger the adhesion coefficient K, the better the adhesion degree of the corresponding plunger coating layer; among them, The method for detecting the adhesion coefficient in Step 1 specifically includes the following steps: Step 101: Obtain the plunger to be tested, longitudinally divide the plunger into two halves, and take one of them as the specimen; Step 102: Conduct a tensile test on the specimen, measure the tensile stress and yield stress when cracks occur in the coating layer of the specimen, and record them as F1 and F2 respectively; Step 103: Substitute the tensile stress F1 and yield stress F2 obtained in Step 2 into formula (1) to obtain the adhesion coefficient K, K = F1 / F2 (1).

7. The method according to claim 6, wherein The method evaluates the adhesion degree of the coating layer of the plunger plasma spraying, plasma surfacing, spray welding and remelting or amorphous alloy process.

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