In-situ observation device for hydrogen distribution in metal

Abstract

The utility model relates to the technical field of metal corrosion, in particular to an in-situ observation device for hydrogen distribution in metal. The in-situ observation device for the gathering position of diffusible hydrogen in metal is realized by adopting a high-pressure gas-phase hydrogen charging mode, the thickness of a metal sample is large, and the gas-phase hydrogen charging efficiency is low. In order to solve the problems, the utility model provides an electrochemical hydrogen charging container device which comprises a developing container, a hydrogen charging container and a sample fixing structure, the developing container and the hydrogen filling container are both containers with open upper parts and closed peripheries and bottoms, a containing cavity of the developing container is positioned in a containing cavity of the hydrogen filling container, and the developing container is vertically suspended and erected on the upper edge of the hydrogen filling container through an extension part on the upper edge of the developing container; the sample fixing structure comprises a cover plate, and an observation hole is formed in the surface of the cover plate; a through hole is formed in the bottom of the developing container, a circle of sealing layer is fixedly arranged on the edge of the through hole in the circumferential direction, the cover plate is attached to the sealing layer in the circumferential direction in a sealed mode, the periphery of the edge of the cover plate is detachably and fixedly connected with the bottom wall of the developing container, and the observation hole and the through hole are vertically opposite and communicated with each other. The hydrogen filling container contains a hydrogen filling solution, the developing container contains a developing reagent, the metal sample is fixed in the sample fixing structure, and the diffusible hydrogen distribution and gathering position on the surface of the metal sample can be observed in real time through the observation hole in the electrochemical hydrogen filling process.

Description

Technical Field

[0001] The utility model relates to the technical field of metal corrosion, in particular to an in-situ observation device for hydrogen distribution in metal. Background Art

[0002] Hydrogen (H) adsorption and diffusion into metals can cause hydrogen embrittlement (HE), leading to premature fracture. Hydrogen accumulates in metals at microstructures such as grain boundaries, twin boundaries, dislocations, and the precipitate-matrix interface. Therefore, understanding the interaction between H and microstructure is key to understanding the nature of hydrogen embrittlement.

[0003] The main methods for detecting hydrogen distribution in metals include three-dimensional atom probe tomography (APT), scanning Kelvin probe force microscopy (SIMS), secondary ion mass spectrometry (SIMS) and hydrogen microprinting technique (HMT). Among them, APT, SKPFM and SIMS methods have complicated operation procedures, expensive equipment and instruments, and difficult sample preparation; HMT is a method of detecting hydrogen distribution in metals by Ag. + The displacement reaction is used to detect hydrogen, which can intuitively indicate the location of hydrogen escape and is simple to operate.

[0004] Chinese patent CN118275512A discloses an in-situ hydrogen microprinting method. This method involves charging one side of a sample with 10 MPa vapor-phase hydrogen and analyzing the hydrogen distribution in the metal using a hydrogen developer on the other side. While this method allows for in-situ observation, it has several drawbacks: Firstly, the vapor-phase hydrogen charging efficiency is low and the cycle time is long; secondly, the sample thickness must meet the pressure vessel wall thickness requirements, resulting in a very large sample thickness. Therefore, this method is not practically feasible. Furthermore, the high-pressure hydrogen involved makes it highly dangerous and unsuitable for standard laboratories.

[0005] Therefore, developing a simple, fast experimental method that can identify the order of hydrogen aggregation in the microstructure is of great significance for conducting hydrogen distribution detection in general laboratories. Utility Model Content

[0006] The existing technology has the following problems: the in-situ observation device for the location of diffused hydrogen accumulation in metals using high-pressure gas-phase hydrogen charging is too thick for metal samples, resulting in low gas-phase hydrogen charging efficiency. To address the above problems, the present invention provides an electrochemical hydrogen charging container device, which includes a developing container, a hydrogen charging container, and a sample fixing structure;

[0007] The developing container and the hydrogen charging container are both containers with an upper opening and sealed around the sides and bottom. The accommodating cavity of the developing container is located within the accommodating cavity of the hydrogen charging container. The developing container is vertically suspended on the upper edge of the hydrogen charging container through an extension of its upper edge.

[0008] The sample fixing structure includes a cover plate, and an observation hole is opened on the surface of the cover plate;

[0009] A through hole is provided at the bottom of the developing container, a sealing layer is fixedly provided circumferentially on the edge of the through hole, the cover plate is circumferentially tightly fitted with the sealing layer, the edge of the cover plate is detachably fixedly connected to the bottom wall of the developing container, and the observation hole is vertically opposite to the through hole and is connected to each other.

[0010] Preferably, the detachable fixed connection is a screw fixed connection.

[0011] Preferably, the diameter of the observation hole is not less than the diameter of the through hole, which is more convenient for observation with a microscope.

[0012] An in-situ observation device for hydrogen distribution in metal comprises the electrochemical hydrogen charging container device, a microscope and an electrochemical hydrogen charging circuit connection system.

[0013] Preferably, the microscope is a telephoto optical microscope.

[0014] Preferably, the electrochemical hydrogen charging circuit connection system includes a DC power supply, a wire and a platinum sheet. The platinum sheet is connected to the positive electrode of the DC power supply through the wire, and the negative electrode of the DC power supply is soldered to the sample through the wire.

[0015] The utility model has the following beneficial effects:

[0016] (1) The experimental device of the utility model is simple, easy to operate, and has a low experimental threshold. It uses a hydrogen charging solution for electrochemical hydrogen charging, has high hydrogen charging efficiency, does not require high thickness of the metal sample, and has good safety;

[0017] (2) The developing container and the hydrogen filling container in the present invention are detachable structures. After each test is completed, the developing container can be quickly taken out from the hydrogen filling container. No complicated disassembly and assembly is required, and a new metal sample can be replaced, which improves work efficiency.

[0018] Attached drawings:

[0019] Figure 1 : This is a structural schematic diagram of an in-situ observation device for hydrogen distribution in metal provided by the utility model.

[0020] Figure 2 :yes Figure 1 A partial enlarged view of point A in the middle.

[0021] Figure 3 : This is a top view of an in-situ observation device for hydrogen distribution in metal provided by the utility model.

[0022] In the figure: 1. microscope, 2. hydrogen developing solution, 3. developing container, 4. hydrogen filling container, 5. hydrogen filling solution, 6. platinum sheet, 7. DC power supply, 8. wire, 9. sample fixing structure, 91. sample, 92. sealing layer, 93. cover plate, 94. screw. DETAILED DESCRIPTION

[0023] The present invention will be described in detail below with reference to the following examples. However, it should be understood that the following examples are merely illustrative of the embodiments of the present invention and are not intended to limit the scope of the present invention.

[0024] like Figure 1-3 As shown, an electrochemical hydrogen charging container 4 device provided by the present invention includes a developing container 3, a hydrogen charging container 4 and a sample fixing structure 9; the developing container 3 and the hydrogen charging container 4 are made of transparent polytetrafluoroethylene and glass respectively.

[0025] The developing container 3 and the hydrogen charging container 4 are both containers with an upper opening and sealed around the sides and bottom. The accommodating cavity of the developing container 3 is located within the accommodating cavity of the hydrogen charging container 4. The developing container 3 is vertically suspended on the upper edge of the hydrogen charging container 4 by an extension of its upper edge.

[0026] The sample fixing structure 9 includes a cover plate 93 , and an observation hole is opened on the surface of the cover plate 93 ; the cover plate 93 is made of an acrylic plate.

[0027] A through hole is provided at the bottom of the developing container 3, and a sealing layer 92 is fixedly provided around the edge of the through hole. The sealing layer 92 is made of rubber. The cover plate 93 is circumferentially tightly fitted with the sealing layer 92. The edges of the cover plate 93 are detachably fixedly connected to the bottom wall of the developing container 3. The observation hole is vertically opposite to the through hole and is connected to each other.

[0028] In a specific embodiment, the detachable fixed connection is a screw 94 fixed connection.

[0029] In a specific embodiment, the diameter of the observation hole is not less than the diameter of the through hole, which is more convenient for observation by the microscope 1 .

[0030] A device for in-situ observation of hydrogen distribution in metal comprises the electrochemical hydrogen charging container 4, a microscope 1 and an electrochemical hydrogen charging circuit connection system.

[0031] In a specific embodiment, the microscope 1 is a telephoto optical microscope 1 .

[0032] In a specific embodiment, the electrochemical hydrogen charging circuit connection system includes a DC power supply 7, a wire 8, and a platinum sheet 6. The platinum sheet 6 is connected to the positive electrode of the DC power supply 7 via the wire 8. The negative electrode of the DC power supply 7 is soldered to the metal sample 91 via the wire 8. The wire 8 is made of copper wire.

[0033] Here’s how to use it:

[0034] (1) The observation hole on the surface of the cover plate 93 has the same diameter as the through hole on the bottom of the developing container 3 and is vertically aligned with it. A sheet metal sample 91, such as pure iron, is placed between the cover plate 93 and the sealing layer 92. The edge of the cover plate 93 is fastened with screws 94 to firmly fix the metal sample 91 above the bottom of the developing container 3.

[0035] (2) Pour an appropriate amount of hydrogen solution 5, such as a mixed solution of sulfuric acid and thiourea, into the hydrogen container 4. Use a graduated cylinder to measure 27 mL of H2SO4 and pour it into a beaker containing 900 mL of deionized water along a glass rod, stirring with a glass rod while pouring. Then, use a balance to weigh 1 g of thiourea and pour it into the beaker. Add deionized water to the beaker to make the volume to 1000 mL and stir evenly with a glass rod. The amount of the hydrogen solution 5 must ensure that it is always in contact with the lower surface of the sheet metal sample. The negative electrode of the DC power supply 7 is connected to the metal sample 91, such as pure iron, through a wire 8. The positive electrode of the DC power supply 7 is connected to the platinum sheet 6 and then immersed in the hydrogen solution 5.

[0036] (3) Pour an appropriate amount of hydrogen developing solution 2, such as K[Ag(CN)2] aqueous solution, into the developing container 3. Weigh 0.43 g of K[Ag(CN)2] solid powder and pour it into a beaker containing 500 mL of deionized water. Stir evenly with a glass rod until the hydrogen developing solution 2 covers the cover plate 93.

[0037] (4) Turn on the DC power supply 7 to start powering on, and then use the telephoto optical microscope 1 to align the observation hole above the developing container 3 to observe the hydrogen diffusion sequence and hydrogen accumulation position of the sheet metal sample in real time.

[0038] Based on the above-mentioned ideal embodiment of the present invention, and in accordance with the above description, relevant personnel can make various changes and modifications without departing from the technical scope of the present invention. The technical scope of the present invention is not limited to the content of the specification, but must be determined according to the scope of the claims.

Claims

1. An electrochemical hydrogen charging container (4) device, characterized in that: It comprises a developing container (3), a hydrogen filling container (4) and a sample fixing structure (9); The developing container (3) and the hydrogen charging container (4) are both containers with an upper opening and sealed around the sides and bottom. The accommodating cavity of the developing container (3) is located within the accommodating cavity of the hydrogen charging container (4). The developing container (3) is vertically suspended on the upper edge of the hydrogen charging container (4) through an extension of its upper edge. The sample fixing structure (9) includes a cover plate (93), and an observation hole is opened on the surface of the cover plate (93); A through hole is provided at the bottom of the developing container (3), a sealing layer (92) is fixedly provided around the edge of the through hole, the cover plate (93) is circumferentially and tightly fitted with the sealing layer (92), the edge of the cover plate (93) is detachably and fixedly connected to the bottom wall of the developing container (3), and the observation hole is vertically opposite to the through hole and is connected to each other.

2. An electrochemical hydrogen charging container (4) device according to claim 1, characterized in that: The detachable fixed connection is a screw (94) fixed connection.

3. An electrochemical hydrogen charging container (4) device according to claim 1, characterized in that: The diameter of the observation hole is not less than the diameter of the through hole.

4. An in-situ observation device for hydrogen distribution in metal, characterized in that: The invention comprises an electrochemical hydrogen charging container (4) device according to any one of claims 1 to 3.

5. The in-situ observation device for hydrogen distribution in metal according to claim 4, characterized in that: Also included is a microscope (1).

6. The in-situ observation device for hydrogen distribution in metal according to claim 5, characterized in that: The microscope (1) is a telephoto optical microscope (1).

7. The in-situ observation device for hydrogen distribution in metal according to claim 4, characterized in that: The invention also includes an electrochemical hydrogen charging circuit connection system, wherein the electrochemical hydrogen charging circuit connection system includes a DC power supply (7), a wire (8) and a platinum sheet (6), wherein the platinum sheet (6) is connected to the positive electrode of the DC power supply (7) through the wire (8), and the negative electrode of the DC power supply (7) is soldered to the sample (91) through the wire (8).

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