A horizontal motion immersion test device for achieving eddy current-free

Abstract

The present invention provides a device for realizing a horizontal motion immersion test without eddy currents, which relates to the field of corrosion performance detection technology. The device comprises a box, a solution tank, and a sample moving part. One end of the sample moving part is connected to the box, and the other end of the sample moving part extends into the solution tank. The sample moving part comprises a fixed part, a moving part, a supporting part, and a lifting assembly. The fixed part is connected to the moving part, the moving part is connected to the supporting part, the supporting part is connected to the lifting assembly, and the lifting assembly is arranged above the box. The fixed part is a cube sample holder structure, and the cube sample holder includes a long side and a short side. The sample is fixed on the fixed part. When the sample is subjected to a horizontal motion immersion test, the sample moves in the direction along the long side of the cube sample holder. The device of the present invention can realize a horizontal motion without eddy current test during a waterline corrosion test and a full immersion corrosion test, making the test more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion performance detection, in particular to a horizontal motion immersion test device capable of realizing no eddy current. Background Art

[0002] Offshore platforms are important facilities for offshore oil and gas exploration, development, and production. They are widely made of welded cylindrical components (such as high-strength steel pipe rack structures). The underwater parts are corroded by seawater for a long time and are inevitably damaged by corrosion or stress corrosion, which may lead to reduced structural strength and cause safety accidents. Therefore, before the use of offshore platform materials, it is necessary to conduct relevant corrosion tests in the laboratory to select materials with better performance.

[0003] The underwater part of the offshore platform is completely immersed in seawater, which belongs to the category of full immersion corrosion. At present, the laboratory simulation of full immersion corrosion mainly adopts the method of beaker immersion + water bath insulation. In fact, there is a certain relative speed between the underwater part of the offshore platform and the seawater. The maximum scouring speed at the sea surface can reach 3m / s. The flow velocity of the underwater part decreases with the increase of depth, but it is not completely static. The seawater moves relative to the steel structure with the wind or the ebb and flow of the tide, and there is a reciprocating fluid "scouring" effect. The conventional static immersion method is not suitable for the service environment and needs to be simulated in a dynamic immersion (scouring) corrosion device. In the process of studying the dynamic immersion (scouring) corrosion performance of metal materials, in addition to temperature, O2 content, Cl - While factors like concentration significantly influence corrosion performance, the influence of relative velocity on corrosion outcomes cannot be ignored. Studies have shown that the corrosion rate of hull steel in seawater at 1 m / s and 0.1 m / s can differ by 6-8 times. Because existing equipment typically lacks accurate scouring velocity values, little research has been conducted on the differences in material corrosion performance at smaller scouring velocity intervals (such as 0.1 m / s), making it difficult to determine a safe critical scouring velocity (i.e., the velocity below which a material is considered safe).

[0004] There are generally two types of erosion corrosion test devices. One is a rotary type, such as CN 117629861 A, CN118817585 A, CN 109298062 B, CN 114739846 A, CN 115683997 A, CN 117405542 A, etc., which all use a rotary method to obtain relative velocity. There are two rotation methods. One is sample movement (medium is stationary), that is, the relative movement of the sample and the medium is simulated by rotating the rotating shaft to drive the sample mounted on the sample holder. The relative linear velocity of the sample and the medium can be calculated by the rotation speed and the holder radius. For example, for a holder with a radius of 200mm, it rotates 47 times per minute, and the speed between the sample and the medium is 1m / s. This calculation method is based on the theoretical assumption that the medium in the test container is stationary. However, the actual situation is that as the rotation time increases, the medium in the container will gradually form a vortex. The faster the speed, the more obvious the vortex, and the specific relative speed between the two is unknown. The other is that the sample is stationary, and the medium rotation movement is controlled by a stirring rod. The speed of the sample position can be measured and controlled by a speedometer, but the speed in different areas still varies greatly. Therefore, the control system is relatively complex and difficult to implement.

[0005] Another type of erosion corrosion test device is the pipe flow type. Patents such as CN 114384003 A, CN 116754464 A, and CN118500962 A all use pipeline medium flow to determine erosion velocity. By adjusting the velocity of the medium in the pipeline, the medium flows directly over the specimen or sprays it onto a stationary specimen surface. These devices typically require a large space for installation and operation, and utilize a PLC as the main control unit to control temperature and flow rate. These algorithms vary significantly, and they also cannot accurately control the seawater flow rate in the pipeline. Currently, there is no standard test method available for dynamic immersion (erosion) testing. Comparisons of different material types can only be conducted within the same device. Corrosion rates measured for the same material by different testing agencies vary significantly, making them incomparable and significantly reducing the practical value of the data. Furthermore, the erosion direction of these rotary and pipe flow devices remains constant, meaning the direction of action of the corrosive medium and the specimen remains constant. This is inconsistent with the reciprocating dynamic immersion (erosion) experienced by offshore platform steel structures, making it impossible to accurately measure the corrosion performance of steel structures under simulated offshore service conditions. Summary of the Invention

[0006] In light of this, the present invention aims to propose a horizontal motion immersion test device that achieves eddy current-free operation. This approach addresses existing issues, such as the difficulty in accurately controlling the relative velocity between the specimen and the medium, caused by static immersion corrosion that is inconsistent with the service environment, the vortex formation during the test in rotary dynamic immersion (scouring) test devices, and the influence of the control algorithm in tube-flow dynamic immersion (scouring) test devices.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] A device for realizing a horizontal motion immersion test without eddy currents comprises a box body, a solution tank, and a sample moving part, wherein one end of the sample moving part is connected to the box body, and the other end of the sample moving part extends into the solution tank, and the sample moving part comprises a fixed part, a moving part, a supporting part, and a lifting assembly, wherein the fixed part is connected to the moving part, the moving part is connected to the supporting part, and the supporting part is connected to the lifting assembly, and the lifting assembly is arranged above the box body, the fixed part is a cube sample holder structure, and the cube sample holder comprises a long side and a short side, and the sample is fixed on the fixed part. During the horizontal motion immersion test of the sample, the sample movement direction is along the long side of the cube sample holder.

[0009] This setting can realize horizontal motion-free eddy current testing during waterline corrosion testing and full immersion corrosion testing, making the test more accurate.

[0010] Furthermore, the size of the cube sample holder is 220~260mm×28~32mm×8~12mm.

[0011] Furthermore, the fixing part is provided with a connection center, a slot, a first flow guide hole, a second flow guide hole, and a water flow area. The connection center is located at the center of the fixing part, the slot is located on the long side of the cube sample holder, the first flow guide hole is located on the short side of the cube sample holder, the second flow guide hole is located on the long side of the cube sample holder, and the water flow area is located inside the cube sample holder and is connected to the first flow guide hole and the second flow guide hole.

[0012] This setting can not only ensure the strength of the fixed part and improve its service life, but also minimize the influence of the cube specimen holder on the test fluid during the horizontal movement test of the specimen, achieve eddy current-free, reduce test errors, and improve the accuracy of the test.

[0013] Furthermore, the card slot is a cube structure, and a plurality of the card slots are provided.

[0014] The card slots in this setup can be used to insert multiple specimens, improving the accuracy of the test.

[0015] Furthermore, when the sample is fixed in the slot, the smallest surface of the sample is perpendicular to the movement direction.

[0016] This setting effectively reduces the generation of eddy currents during testing.

[0017] Furthermore, the second guide hole is located between any two adjacent card slots.

[0018] Furthermore, the second guide hole is an X-shaped guide hole.

[0019] This arrangement allows the water outside the fixing portion to flow out from multiple directions of the fixing portion after passing through the inside of the fixing portion during testing, thereby reducing the impact of the water flow on the specimen and effectively reducing the generation of eddy currents.

[0020] Furthermore, the fixing portion is provided with a bolt hole, the bolt hole is located on the long side of the cube specimen holder, and the bolt hole is communicated with the slot, and the bolt hole is used for screwing in a bolt to fix the specimen.

[0021] Furthermore, the moving part includes a slider, a driving member, and a connecting rod, the slider is connected to the driving member, the driving member is connected to the connecting rod, the connecting rod is connected to the fixed part, and the connecting rod is inserted into the connection center and connected to the fixed part.

[0022] Furthermore, all edges and corners of the fixing portion are smoothly polished, with a surface roughness of ≤1.6 μm.

[0023] In this setup, by optimizing the fixing structure, eddy currents can be eliminated during corrosion testing.

[0024] Furthermore, the support portion includes a slide rail, the slider moves on the slide rail, and the slide rail is connected to the lifting assembly.

[0025] Compared with the prior art, the eddy current-free horizontal motion immersion test device described in the present invention has the following advantages:

[0026] 1) The device of the present invention can be applied to dynamic immersion corrosion testing of raw materials in liquids. During waterline corrosion testing, the specimen is partially immersed in the solution, while the specimen holder remains. During horizontal movement, the relatively small relative motion area of ​​the specimen (e.g., 100 mm x (≤3) mm) coupled with a relatively wide solution tank (500 mm wide) and reverse motion (the specimen reaches the edge, triggering a mechanical limiter and subsequently moving in the opposite direction) counteracts any weak eddies that may form as a result of the interaction between the specimen and the solution. During full immersion corrosion testing, the thin, narrow, smooth holder (e.g., 30 mm wide x 10 mm thick) and the three types of holes in the holder prevent eddies from forming due to holder movement, ensuring that the solution remains essentially stationary at speeds of (0-3) m / s, ensuring stable and precise relative velocity between the specimen and the liquid during the test. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a structural diagram of a horizontal motion immersion test device for achieving eddy current-free performance according to the present invention;

[0028] Figure 2 It is a structural schematic diagram of the connection between the fixed part and the movable part of the present invention;

[0029] Figure 3 Schematic diagram of the overall structure of the sample moving part of the present invention;

[0030] Figure 4 It is a schematic diagram of the overall structure of the fixing part of the present invention.

[0031] Description of reference numerals:

[0032] 1-box, 11-electric heating plate, 12-solution box, 13-pure water tank, 14-air box thermometer and hygrometer, 15-liquid level gauge, 16-mechanical limit, 2-solution tank, 3-sample moving part, 31-fixed part, 311-connection center, 312-slot, 313-first guide hole, 314-second guide hole, 315-water flow area, 3151-first area, 3152-second area, 316-bolt hole, 317-bracket center guide hole, 32-moving part, 321-slider, 322-driving part, 323-connecting rod, 33-support part, 331-slide rail, 34-lifting assembly, 4-control box, 5-sample, a-long side, b-short side. DETAILED DESCRIPTION

[0033] To make the above-mentioned objects, features, and advantages of the present invention more readily apparent, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In addition, a brief explanation is provided regarding the directions or positional relationships involved in the following specific embodiments: The directions or positional relationships indicated by the terms "up," "down," "left," "right," "front," and "back" mentioned in the embodiments refer to the directions or positional relationships shown in the accompanying drawings.

[0034] The relative velocity between the corrosive medium and the material is a key factor influencing the material's corrosion behavior. Conventional rotary and pipe-flow erosion corrosion testing devices struggle to precisely control the relative velocity, resulting in significant discrepancies in test results from different testing institutions. This significantly reduces the practicality of the data, making it difficult to optimize material properties and hindering the development of the marine materials industry. Therefore, there is an urgent need to design a device that allows the test sample to withstand the reciprocating erosion of the medium while maintaining a precisely controlled relative velocity and preventing the formation of eddies.

[0035] The purpose of the present invention is achieved as follows: from the perspective of reciprocating motion, moving in a straight line is the simplest, and to accurately control the relative speed, it is necessary to work hard on the interaction area. According to the principle of fluid motion, the fluid resistance F=1 / 2CρAν 2, where C is the drag coefficient (constant for the same type of liquid), ρ is the fluid density, A is the cross-sectional area of ​​the object perpendicular to the direction of motion, and ν is the relative velocity. This means that when a specimen moves in a stationary fluid, the resistance it experiences prevents its motion and is positively correlated with the perpendicular cross-sectional area and the relative velocity. This resistance, in turn, acts on the fluid, causing it to flow in the direction of the specimen's motion. In other words, the greater the resistance, the more likely eddies are to form. To minimize eddies, when the velocity remains constant, the area of ​​action must be minimized. The Froude number (Fr) in fluid mechanics characterizes the flow pattern of water. The specific formula is as follows:

[0036]

[0037] Among them, ν is the relative velocity, g is the acceleration due to gravity, and h is the water depth. When Fr is small, the water flow is slow and stable. When Fr is large, the water flow is fast and eddies are more likely to appear. To reduce the degree of eddies, when the speed remains unchanged, the water depth should be increased as much as possible. In addition, according to the Bernoulli equation of fluid mechanics "p+1 / 2ρν 2 +ρgh=constant" (where p is pressure, ρ is fluid density, ν is fluid velocity, and h is height) shows that the main reason for fluid vortex formation is the existence of pressure differences. When the water surface is wide, the conditions for vortex formation are more stringent, requiring a sufficiently large area or a sufficiently high relative velocity to produce sufficient flow velocity changes and pressure differences across the vast water surface. When the water surface is narrow, the water flow is easily disturbed by the boundary, making vortex formation more likely. Therefore, to reduce the degree of vortex, when the velocity remains unchanged, the width of the water surface (or depth, where depth is the bottom boundary) needs to be increased.

[0038] Based on the above analysis, the vortex index Ivory can be expressed as follows:

[0039]

[0040] Among them, C d is the fluid resistance, B is the width of the water surface, h is the depth of the water surface, and k, m, and n are constants. The above formulas show that when the fluid surface in the solution tank is wide enough, the volume is large enough (deep enough), and the interaction area with the specimen is small enough, the boundary's constraints and reflections on the fluid near the object will have an extremely weak effect, confining the specimen's influence on the fluid to a small area around it. From the perspective of the overall fluid, its impact is negligible. Furthermore, by optimizing the bracket shape and setting appropriate diversion holes, resistance can be further reduced and water flow pressure balanced. This allows the design of a dynamic test device that can negligibly affect eddy currents.

[0041] like Figures 1 to 4As shown, the present invention proposes a horizontal motion immersion test device for achieving eddy current-free, comprising a box 1, a solution tank 2, and a sample moving part 3, wherein one end of the sample moving part 3 is connected to the box, and the other end of the sample moving part extends into the solution tank, the sample moving part 3 comprises a fixed part 31, a moving part 32, a supporting part 33, and a lifting assembly 34, wherein the fixed part 31 is connected to the moving part 32, the moving part 32 is connected to the supporting part 33, and the supporting part 33 is connected to the lifting assembly 34, the lifting assembly is arranged above the box, and the lifting assembly is conventional prior art, the fixed part is a cube sample holder structure, the cube sample holder comprises a long side a and a short side b, the sample 5 is fixed on the fixed part, and during the horizontal motion immersion test of the sample, the sample movement direction is along the long side a of the cube sample holder.

[0042] As a preferred embodiment of the present application, the planar dimensions of the solution tank are 1900-2100 mm in length and 480-520 mm in width. More preferably, the planar dimensions of the solution tank are 2000 mm in length and 500 mm in width.

[0043] Specifically, the test apparatus further includes a control box 4, which houses a controller comprising an electrical system, control software, and a touch screen display. The control box is used to control the solution tank temperature, the temperature and humidity of the chamber, the sample movement speed, and the salt water inlet and pure water replenishment. These are all prior art and will not be described in detail here.

[0044] Specifically, the box body 1 is provided with an electric heating plate 11, a solution tank 12, a pure water tank 13, an air box thermometer and hygrometer 14, a liquid level gauge 15, a mechanical limit 16, an air heating rod (not shown in the figure), a thermocouple (not shown in the figure), a solution tank cover (not shown in the figure), a pipetting pump (not shown in the figure), and a water supply pump (not shown in the figure). The mechanical limit structure is generally a spring card structure, a mature product, combined with a control system. When the bracket touches the limit, it moves in the opposite direction, and then moves in the opposite direction again when it touches the mechanical limit on the other side. In this cycle, the electric heating plate is arranged in the middle position of the box body, the solution tank is located on the electric heating plate, the electric heating plate is used to heat the water temperature in the solution tank, the thermocouple is arranged in the solution tank, and is used to control the temperature in the solution tank, the solution tank and the pure water tank are both located at the bottom of the box body, the air box hygrometer is arranged at the upper end of the solution tank, the liquid level meter is inserted into the solution tank, the air heating rod, thermocouple, solution tank cover, pipetting pump, and water supply pump are all mature products, and the connection method is also the existing technology and will not be described in detail here.

[0045] More specifically, the solution tank is equipped with a pipette pump, and the pure water tank is equipped with a water replenishment pump. Both are connected to the solution tank level gauge, enabling precise control of the corrosion solution concentration, temperature, and humidity during the test. More specifically, first adjust the level gauge position, open the solution tank inlet switch, and the test solution enters the solution tank via the pipette pump. Liquid inflow stops when it reaches the level gauge. Second, close the solution tank inlet switch and open the pure water inlet switch. If the water level in the solution tank drops below the level gauge position due to evaporation during the test, the water replenishment pump will pump pure water into the solution tank and stop when the water level reaches the level gauge position. The pump remains connected throughout the experiment to ensure that the solution concentration remains constant. Temperature and humidity control is based on feedback from the thermocouple and hygrometer to the control system, thereby controlling the temperature and humidity of the air chamber, which is consistent with conventional constant temperature and humidity chambers.

[0046] As a preferred embodiment of the present application, the dimensions of the cube sample holder are length (220-260 mm) × width (28-32 mm) × thickness (8-12 mm). More preferably, the dimensions of the cube sample holder are length 240 mm × width 30 mm × thickness 10 mm.

[0047] Specifically, the fixing portion 31 is provided with a connection center 311, a slot 312, a first guide hole 313, a second guide hole 314, a water flow area 315, and a bolt hole 316. The connection center 311 is located at the center of the fixing portion. The connection center 311 is used to connect the fixing portion and the moving portion. The setting of the connection center makes the entire fixing portion more stable, ensuring that there is no eddy current when the sample moves; the slot 312 is located on the long side of the cube sample holder, the first guide hole 313 is located on the short side b of the cube sample holder, and the second guide hole 314 is located on the short side b of the cube sample holder. On the long side of the sample holder, the water flow area 315 is located inside the cube sample holder and is connected to the first guide hole and the second guide hole. The bolt hole 316 is located on the long side of the cube sample holder and is connected to the card slot. The bolt hole is used to screw the bolt into the fixed sample. By setting the first guide hole, the second guide hole and the water flow area, the strength of the fixing part can be guaranteed and the service life can be improved. At the same time, during the horizontal movement test of the sample, the influence of the cube sample holder on the test fluid can be minimized to the greatest extent, achieving no eddy current, reducing test errors, and improving the accuracy of the test.

[0048] As a preferred embodiment of the present application, all edges and corners of the fixing portion 31 are smoothly polished, and the surface roughness is ≤1.6 μm.

[0049] As a preferred embodiment of the present application, the connection center 311 is a circular hole with a thread inside, and the fixed part and the movable part are fixed by a threaded connection.

[0050] As a preferred embodiment of the present application, the card slot 312 is a cube structure. There are multiple card slots, preferably, six card slots are provided on each of the two long sides.

[0051] As a preferred embodiment of the present application, a plurality of the first flow guide holes 313 are provided. Preferably, two first flow guide holes are provided.

[0052] As a preferred embodiment of the present application, the second guide hole 314 is located between any two adjacent card slots, and the second guide hole 314 is an X-shaped guide hole.

[0053] As a preferred embodiment of the present application, a central guide hole 317 of the bracket is further provided on the fixing portion 31, and the water flow area 315 includes a first area 3151 and a second area 3152 that are symmetrical to each other. The first area and the second area are symmetrically arranged with respect to the connection center. The central guide hole 317 of the bracket can enable water in the first water area and water in the second water area to circulate with each other, reducing the possibility of vortexes. A hole (not shown in the figure) is provided on the connecting rod 323. When the connecting rod 323 is screwed into the connection center, the central guide hole of the bracket is connected to the hole on the connecting rod.

[0054] Specifically, the moving part 32 includes a slider 321, a driving member 322, and a connecting rod 323. The slider 321 is connected to the driving member 322, the driving member 322 is connected to the connecting rod 323, the connecting rod is connected to the fixed part, and the connecting rod 323 is inserted into the connection center and connected to the fixed part; the supporting part 33 includes a slide rail 331, the slider 321 moves on the slide rail, and the slide rail is connected to the lifting assembly.

[0055] Preferably, the driving member is a servo motor.

[0056] A method for implementing a horizontal motion immersion test without eddy currents, using the above-mentioned device, specifically comprising the following steps:

[0057] S1. Install the specimen on a cube specimen holder, with the smallest surface of the specimen perpendicular to the direction of motion;

[0058] Specifically, the sample is pre-treated. Pre-treatment involves cleaning, measuring the dimensions, and weighing the processed sample to obtain its initial mass. The pre-treated sample (typical dimensions are 160 mm long, 30 mm wide, and (≤3) mm thick) is placed in the slot on the cube sample holder and fixed with a polytetrafluoroethylene screw through the sample fixing threaded hole. The sample holder with the mounted sample is then connected to the moving part and the supporting part in sequence.

[0059] S2. Add the test solution and high-purity water. Adjust the position of the level gauge to determine the liquid level according to the experimental purpose, and introduce the test solution into the solution tank.

[0060] Specifically, turn on the controller, add the test medium (such as artificial seawater) to the solution tank, adjust the position of the liquid level gauge in the solution tank according to the experimental purpose, determine the liquid level, and close the liquid inlet switch after the test solution is added; add pure water to the pure water tank and turn on the pure water inlet switch. At this time, the pure water tank is connected to the liquid level gauge in the solution tank. When the liquid level drops, pure water can be automatically added to ensure that the solution level remains unchanged during the test;

[0061] S3. Control the test cube specimen holder through the controller and determine the specimen position according to the test purpose;

[0062] Specifically, the lifting assembly is controlled to drive the support part downward, drive the moving part downward, and adjust the position of the sample in the solution tank. The sample is completely immersed in the solution to simulate a full immersion corrosion test; the sample is partially immersed in the solution to simulate a waterline corrosion test. At this time, the length and width of the sample (160mm×30mm) are parallel to the direction of movement.

[0063] S4. Set the test parameters, including temperature, humidity, speed, etc.; finally, start the equipment to officially start the dynamic immersion test (including full immersion flushing and waterline flushing test).

[0064] Specifically, parameters include, but are not limited to, water tank temperature (e.g., 35°C), dynamic immersion speed (e.g., 1m / s), and test time (e.g., 720h). After the test begins, the driver drives the connecting rod to cause the slider to move horizontally within the rail, simultaneously driving the specimen on the specimen holder to move horizontally within the solution tank. When the moving part reaches the mechanical limit, the system software controls the reverse movement. This cycle repeats, conducting a dynamic immersion corrosion test without eddy currents. (During the waterline corrosion test, the specimen is only partially immersed in the solution. If air temperature and humidity control is required, the air box temperature and humidity can be further set (e.g., 35°C, 75% RH).

[0065] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Example 1

[0066] Six specimens measuring 160 mm x 30 mm x 3 mm were collected from a 40 mm thick low-alloy steel plate along the surface deformation direction. Prior to testing, the specimens were marked, measured, cleaned, and weighed. Three of these specimens (1#-3) underwent dynamic full-immersion corrosion testing using an experimental apparatus based on the present invention. The solution was artificial seawater at 35°C, at a speed of 1 m / s, and the test lasted for 30 days. To characterize the effect of relative corrosion rate on corrosion acceleration, three other specimens (4#-6) were placed in a QJ-1 rotary full-immersion corrosion tester and subjected to dynamic immersion testing at an initial speed of 1 m / s, with all other conditions remaining the same. After 30 days of testing, the specimens were removed and cleaned of corrosion products in an acid wash solution (500 mL of high-grade pure hydrochloric acid, 500 mL of water, and 3.5 g of hexamethylenetetraammonium). The specimens were then dried and weighed. The changes in specimen mass and corrosion rates are shown in Table 1 below. As can be seen from Table 1, the corrosion rate obtained by using the sample device of the present invention is about 16.4% higher than the corrosion rate obtained by using the rotary full immersion corrosion tester, which proves that the relative speed of the QJ-1 rotary full immersion corrosion tester should be less than 1 m / s.

[0067] Table 1 Mass change and corrosion rate of a low alloy steel sample

[0068] Example 2

[0069] Six specimens measuring 160 mm x 30 mm x 3 mm were collected from a 20 mm thick titanium alloy plate along the surface deformation direction. Prior to testing, the specimens were numbered, measured, cleaned, and weighed. Three of these specimens (11#-13#) were subjected to dynamic waterline corrosion testing using the present invention's test apparatus. The specimens were immersed at a depth of 100 mm in a 3.5% NaCl solution at 35°C, maintained at an air chamber temperature of 30°C, a humidity of 60% RH, and a speed of 1 m / s for 30 days. To characterize the effect of relative corrosion rate on corrosion acceleration, three other specimens (14#-16#) were subjected to dynamic waterline corrosion testing using a QJ-1 rotary full-immersion corrosion tester at an initial speed of 1 m / s, with all other conditions remaining the same. After 30 days, the specimens were removed, cleaned of corrosion products, dried, and weighed. The changes in specimen mass and corrosion rates are shown in Table 2 below. As can be seen from Table 2, the corrosion rate obtained by using the test device of the present invention is 26.8% higher than that obtained by using the rotary full immersion corrosion tester. Combined with the negative static immersion corrosion rate of the titanium alloy, it shows that the dynamic solution accelerates the damage of the titanium alloy passivation film and the corrosion of the substrate. It also proves that the relative speed of the QJ-1 rotary full immersion corrosion tester should be less than 1 m / s.

[0070] Table 2 Mass change and corrosion rate of a titanium alloy sample

[0071]

[0072] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the scope defined by the claims.

Claims

1. A horizontal motion immersion test device for achieving eddy current-free test, comprising a box (1), a solution tank (2), and a sample moving part (3), wherein one end of the sample moving part (3) is connected to the box (1), and the other end of the sample moving part (3) extends into the solution tank (2), characterized in that: The sample moving part (3) includes a fixed part (31), a moving part (32), a supporting part (33), and a lifting assembly (34). The fixed part (31) is connected to the moving part (32), the moving part (32) is connected to the supporting part (33), and the supporting part (33) is connected to the lifting assembly (34). The lifting assembly (34) is arranged above the box (1). The fixed part (31) is a cube sample holder structure. The cube sample holder includes a long side (a) and a short side (b). The sample is fixed on On the fixing part (31), when the sample moves horizontally in the immersion test, the sample moves in the direction along the long side (a) of the cube sample holder; the fixing part (31) is provided with a connection center (311), a slot (312), a first guide hole (313), a second guide hole (314), and a water flow area (315), wherein the connection center (311) is located at the center of the fixing part (31), the slot (312) is located on the long side (a) of the cube sample holder, the first guide hole (313) is located at the center of the cube sample holder, and the second guide hole (314) is located at the center of the cube sample holder. The second guide hole (314) is located on the short side (b) of the cube sample holder, the second guide hole (314) is located on the long side (a) of the cube sample holder, the water flow area (315) is located inside the cube sample holder, and is connected to the first guide hole (313) and the second guide hole (314); the fixing portion (31) is also provided with a center guide hole (317) of the holder, the water flow area (315) includes a first area (3151) and a second area (3152) symmetrical to each other, the first area and the second area are symmetrically arranged with the connection center, and the holder The center guide hole (317) of the frame can allow water in the first water area and water in the second water area to circulate with each other; the second guide hole (314) is located between any two adjacent card slots (312); the second guide hole (314) is an X-shaped guide hole; the fixing portion (31) is further provided with a bolt hole (316), the bolt hole (316) is located on the long side (a) of the cube sample holder, and the bolt hole (316) is communicated with the card slot (312), and the bolt hole (316) is used for screwing in a bolt to fix the sample.

2. The test device according to claim 1, characterized in that The dimensions of the cube sample holder are 220-260 mm×28-32 mm×8-12 mm.

3. The test device according to claim 1, characterized in that The card slot (312) is a cubic structure, and a plurality of the card slots (312) are provided.

4. The test device according to claim 1, characterized in that When the sample is fixed in the slot (312), the smallest surface of the sample is perpendicular to the direction of movement.

5. The test device according to claim 1, characterized in that All corners of the fixing portion are smoothly polished, with a surface roughness of ≤1.6 μm.

6. The test device according to claim 1, characterized in that The movable portion (32) comprises a slider (321), a driving member (322), and a connecting rod (323); the slider (321) is connected to the driving member (322); the driving member (322) is connected to the connecting rod (323); the connecting rod (323) is connected to the fixed portion (31); and the connecting rod (323) is inserted into the connection center and connected to the fixed portion (31).

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