CN115541483A - Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material - Google Patents
Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material Download PDFInfo
- Publication number
- CN115541483A CN115541483A CN202211210191.5A CN202211210191A CN115541483A CN 115541483 A CN115541483 A CN 115541483A CN 202211210191 A CN202211210191 A CN 202211210191A CN 115541483 A CN115541483 A CN 115541483A
- Authority
- CN
- China
- Prior art keywords
- tensile stress
- test
- atmospheric environment
- test piece
- interaction
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N17/00—Investigating resistance of materials to the weather, to corrosion, or to light
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/32—Investigating strength properties of solid materials by application of mechanical stress by applying repeated or pulsating forces
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Immunology (AREA)
- Biochemistry (AREA)
- Pathology (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Analytical Chemistry (AREA)
- Chemical & Material Sciences (AREA)
- Ecology (AREA)
- Environmental Sciences (AREA)
- Biodiversity & Conservation Biology (AREA)
- Environmental & Geological Engineering (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The invention belongs to the technical field of metal material environmental tests, and particularly relates to a marine atmospheric environment-elastic tensile stress interaction test method for a metal material, which comprises the following steps: s1, placing a test piece in an outdoor real marine atmospheric environment to perform a natural environment static exposure test; s2, statically loading elastic tensile stress on the test piece, and placing the test piece in an outdoor real marine atmospheric environment to perform a natural environment exposure test; s3, detecting and obtaining the surface corrosion appearance, the metallographic section appearance, the electrochemical performance parameters and the performance change data of the tensile strength and the elongation after fracture of the test piece; and S4, evaluating the interaction effect, analyzing the corrosion damage rule of the test piece under the interaction of the marine atmospheric environment and the elastic tensile stress, and evaluating the interaction effect. The method can truly and rapidly reflect the corrosion damage rule of the metal structural materials such as aluminum alloy and the like under the condition that the height is close to the actual service working condition.
Description
Technical Field
The invention relates to a method for testing interaction between marine atmospheric environment and elastic tensile stress of a metal material, belonging to the technical field of metal material environmental tests.
Background
Marine clothingThe components of the marine equipment, such as ships, offshore drilling equipment and the like, adopt a large amount of metal materials, wherein the aluminum alloy is one of main structural materials for marine equipment superstructure, is not immersed in seawater for service, but is often impacted by splashed seawater and is in a marine atmospheric environment all day long, the marine atmospheric environment is one of the most severe atmospheric corrosion environments, and has the characteristics of high humidity, high salt fog, remarkable dry/wet alternating effect and the like, a thin liquid film is formed on the surface of the aluminum alloy material, and a Cl film is formed on the surface of the aluminum alloy material - 、O 2 、SO 2 Etc. in the presence of corrosive media. Meanwhile, as a main structural strength bearing material of the marine equipment, the aluminum alloy can bear the stress load effect in an elastic range under most conditions in the actual service process. Therefore, the corrosion damage behavior of the aluminum alloy structural material for the marine equipment upper-layer building in the service process is actually the result of interaction between the marine atmospheric environment and elastic stress, and the interaction between the corrosion damage behavior and the elastic stress can accelerate the corrosion damage process of the aluminum alloy structural material, so that the whole bearing capacity of the member is reduced, the member is finally caused to lose efficacy, and great hidden dangers are brought to the service life, the service safety and the like of the marine equipment.
At present, partial research on interaction between a corrosion environment and elastic stress is carried out at home and abroad, and certain research results are obtained, but due to the limitations of economic cost, test conditions and the like, the currently carried out interaction test research mainly focuses on the electrochemical behavior characterization of an elastic stress loading material in a laboratory solution soaking environment, for example, chinese invention patent with publication No. CN 106769474B discloses a corrosion electrochemical experimental device and a test method for a loading biaxial tension stress sample, and can research the corrosion behavior and the corrosion rule of a metal material in a corrosion medium under biaxial tension stress. However, the corrosion process of the aluminum alloy structural material for the superstructure of the marine equipment under the actual service condition is carried out under a thin liquid film formed in the marine atmospheric environment, the corrosion behaviors and mechanisms of the material in the thin liquid film environment and the solution soaking environment are different inevitably, and the medium factors influencing the corrosion of the two environments are different essentially. Outdoor real ocean atmosphereThe environmental corrosion being Cl - 、SO 2 The corrosion control factors of the laboratory solution soaking environment are relatively single, and the difference of the corrosion control factors and the actual use environment of the aluminum alloy structural material for the superstructure of the marine equipment is larger.
Therefore, the research on the marine atmospheric environment-elastic tensile stress interaction test and evaluation method of the aluminum alloy material is urgently needed to be carried out according to the service characteristics of the upper-layer building structural material of the marine equipment, and the method has important significance for really and quickly examining and evaluating the environmental adaptability of the aluminum alloy structural material and finally improving the service life and service safety of the marine equipment.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides a marine atmospheric environment-elastic tensile stress interaction test method for metal materials, which can truly and quickly reflect the corrosion damage rule of metal structural materials such as aluminum alloy and the like under the condition that the height is close to the actual service working condition, and overcomes the defects that the traditional natural environment static exposure test does not consider the stress load influence and the interaction test developed in a laboratory can not truly reflect the comprehensive influence of various natural climate factors in the marine atmospheric environment.
The technical scheme for solving the technical problems is as follows:
the method for testing the interaction between the marine atmospheric environment and the elastic tensile stress of the metal material comprises the following steps:
s1, placing a test piece in an outdoor real marine atmospheric environment to perform a natural environment static exposure test, wherein no stress load is applied to the test piece in the period;
s2, statically loading elastic tensile stress on the test piece, and placing the test piece in an outdoor real marine atmospheric environment to perform a natural environment exposure test;
s3, detecting and obtaining performance change data of the surface corrosion appearance, the metallographic section appearance, the electrochemical performance parameters, the tensile strength and the elongation after fracture of the test piece;
s4, interaction effect evaluation: and analyzing the corrosion damage law of the test piece under the interaction of the marine atmospheric environment-elastic tensile stress by using the surface corrosion morphology, the metallographic cross section morphology, the electrochemical performance parameters, the tensile strength and the elongation after fracture as evaluation indexes, and evaluating the interaction effect.
On the basis of the technical scheme, the invention can also make the following improvements:
further, the metal material is an aluminum alloy material.
Further, in the step S2, a portable axial tensile stress loading device is used to statically load elastic tensile stress on the test piece.
Further, the portable axial tensile stress loading device and the test piece are placed in an outdoor real marine atmosphere environment together to be exposed.
Further, in the step S2, the value of the elastic tensile stress applied to the test piece is 0.4 σ s -0.8σ s Wherein σ is s The corresponding yield strength of the test material itself.
Further, the elastic tensile stress is a static tensile stress in an elastic range.
Further, in the step S1, the test piece faces south and forms an inclination angle of 45 ° with the horizontal plane, the performance testing period is 3, 6, 9, 12 months, and the performance data of the test piece is obtained before the test and after the end of each period.
Further, in the step S2, the performance detection period is 3, 6, 9, 12 months, during the detection period, the elastic tensile stress is continuously applied to the sample in a static state, and the performance data of the test piece is obtained before the test and after the end of each period.
The invention has the advantages that:
(1) The test conditions provided by the invention are highly approximate to the actual service working condition of the test material, the test result can truly reflect the actual corrosion damage rule of the test material, and the defect that the traditional natural environment static exposure test does not consider the stress load influence and the interaction test developed in a laboratory can not truly reflect the comprehensive effect of various natural climate factors in the marine atmospheric environment is overcome.
(2) Compared with the static exposure test result of the natural environment, the acceleration rate of the marine atmospheric environment-elastic tensile stress interaction test result can reach about 2.5 times, the acceleration is remarkable, and the requirement on the quick environment adaptability evaluation and evaluation of the metal material can be met.
Drawings
FIG. 1 is a schematic view showing the structure and dimensions of a test piece used in the examples;
FIG. 2 is a surface corrosion profile of a 7A04 aluminum alloy subjected to an interaction test for 6 months;
FIG. 3 is a metallographic cross-sectional profile of a 7A04 aluminum alloy after 6 months of an interaction test;
FIG. 4 is a force-displacement curve of a tensile property test of 7A04 aluminum alloy for 6 months of the interaction test;
FIG. 5 is a Nyquist plot of EIS testing of unexposed and interaction specimens at 6 months of testing.
Detailed Description
The principles and features of this invention are described below in conjunction with the following drawings, which are set forth to illustrate, but are not to be construed to limit the scope of the invention.
A test method of a metal material under the static loading interaction of an elastic tensile stress in a marine atmospheric environment. In this example, a 7a04 aluminum alloy bare material was used as a test material, and the dimensions and specifications thereof are shown in fig. 1.
The natural environment static exposure test of the embodiment is carried out in a coastal test field of a smoke platform marine atmosphere test station, a test piece faces south and forms an inclination angle of 45 degrees with the horizontal plane, the performance detection period is 3, 6, 9 and 12 months, and the detection parameters are tensile strength and elongation after fracture.
In this embodiment, the stress-strain relationship of the test material itself is determined by using a tensile tester, and 0.6 σ to be applied is measured s The tensile stress of (a) is converted into a corresponding strain.
Portable axial pull selected for use in the present embodimentThe tensile stress loading device specifically adopts a portable axial tensile stress loading device disclosed in the Chinese utility model patent with the publication number of CN203224399U, a test piece attached with a strain gauge is fixed in the stress loading device, the strain of the test piece reaches the set strain through screwing a loading nut, the strain condition of the test piece is investigated through the strain gauge in the process, and when the tensile stress loaded on the test piece reaches the set stress of 0.6 sigma s And the loading nut is locked.
The portable axial tensile stress loading device loaded with the test piece is integrally exposed on an exposure frame of an offshore test field of a smoke bench marine atmospheric test station to carry out a natural environment exposure test, so that the test piece is subjected to the interaction of marine atmospheric environment-elastic tensile stress, the performance detection period is 3, 6, 9 and 12 months, and the detection performance comprises mechanical performance parameters such as surface corrosion morphology, metallographic cross-section morphology, electrochemical performance, tensile strength and elongation after fracture.
Evaluation of interaction effect:
and analyzing the corrosion damage rule of the test material under the interaction of the marine atmospheric environment and the elastic tensile stress by using the surface corrosion morphology, the metallographic cross section morphology and the like as evaluation indexes.
Fig. 2 and 3 respectively show the surface corrosion morphology and the metallographic cross-section morphology of 7a04 aluminum alloy tested under the interaction of marine atmospheric environment-elastic tensile stress for 6 months. As can be seen from FIGS. 2 and 3, the 7A04 aluminum alloy test piece is obviously corroded under the interaction effect in the form of denudation, the corrosion depth is about 40 μm, a large amount of corrosion products are generated on the surface of the test piece, and the corrosion product film is not compact enough and contains more cracks.
FIG. 4 is a force-displacement curve of a 7A04 aluminum alloy tensile property test of a 7A04 aluminum alloy tested for 6 months under the interaction of marine atmospheric environment-elastic tensile stress, and the tensile strength of the 7A04 aluminum alloy is calculated to be 604MPa, and the elongation after fracture is 7%.
FIG. 5 is a Nyquist plot of alternating Current impedance (EIS) testing of 7A04 aluminum alloy for 6 months of testing under unexposed and interactive conditions, the low frequency region of the plot exhibiting inductive reactance characteristics, and the radius of the capacitive arc of the unexposed sample being significantly greater than the radius of the capacitive arc of the test under interactive conditions for 6 months, indicating that the corrosion rate of the latter is significantly greater than the former.
Interaction test accelerated property evaluation:
the original tensile strength and the elongation after fracture of the 7A04 aluminum alloy are 634MPa and 12 percent respectively, the tensile strength and the elongation after fracture tested for 6 months under the interaction of the marine atmospheric environment and the elastic tensile stress are 604MPa and 7 percent respectively, and the reduction rates of the tensile strength and the elongation after fracture are 4.73 percent and 41.67 percent respectively; the tensile strength and the elongation after fracture of the 7A04 aluminum alloy subjected to the natural environment static exposure test for 6 months are 621MPa and 10 percent respectively, the reduction rates of the tensile strength and the elongation after fracture are 2.05 percent and 16.67 percent respectively, and compared with the natural environment static exposure test, the acceleration rate of the interaction test is about 2.5 times.
Therefore, the marine atmospheric environment-elastic tensile stress interaction test method disclosed by the invention is closer to the real use environment of the aluminum alloy material, can be used for more quickly and accurately testing the corrosion damage condition of the aluminum alloy material under the marine atmospheric environment-elastic tensile stress interaction, and has important significance for assessing and evaluating the environmental adaptability of the aluminum alloy material and improving the service life and service safety of marine equipment.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (8)
1. The marine atmospheric environment-elastic tensile stress interaction test method for the metal material is characterized by comprising the following steps of:
s1, placing a test piece in a marine atmospheric environment to perform a natural environment static exposure test, wherein no stress load is applied to the test piece in the period;
s2, statically loading elastic tensile stress on the test piece, and placing the test piece in a marine atmospheric environment to perform a natural environment exposure test;
s3, detecting and obtaining performance change data of the surface corrosion appearance, the metallographic section appearance, the electrochemical performance parameters, the tensile strength and the elongation after fracture of the test piece;
s4, interaction effect evaluation: and analyzing the corrosion damage law of the test piece under the interaction of the marine atmospheric environment-elastic tensile stress by using the surface corrosion morphology, the metallographic cross section morphology, the electrochemical performance parameters, the tensile strength and the elongation after fracture as evaluation indexes, and evaluating the interaction effect.
2. The marine atmospheric environment-elastic tensile stress interaction test method for a metallic material according to claim 1, wherein the metallic material is an aluminum alloy material.
3. The marine atmospheric environment-elastic tensile stress interaction test method for the metal material as claimed in claim 1 or 2, wherein in the step S2, a portable axial tensile stress loading device is adopted to statically load the elastic tensile stress on the test piece.
4. The marine atmospheric environment-elastic tensile stress interaction test method for the metal material as claimed in claim 3, wherein the portable axial tensile stress loading device and the test piece are placed in the marine atmospheric environment and exposed.
5. The marine atmospheric environment-elastic tensile stress interaction test method for the metallic material according to claim 4, wherein in the step S2, the elastic tensile stress value applied to the test piece is: 0.4 sigma s -0.8σ s ，
Wherein σ s The corresponding yield strength of the test material itself.
6. The marine atmospheric environment-elastic tensile stress interaction test method for a metallic material according to claim 5, wherein the elastic tensile stress is a static tensile stress in an elastic range.
7. The marine atmospheric environment-elastic tensile stress interaction test method for the metal material according to claim 1, wherein in the step S1, the test piece faces south and forms an inclination angle of 45 degrees with the horizontal, the performance test period is 3, 6, 9 and 12 months, and the performance data of the test piece are obtained before the test and after the end of each period.
8. The marine atmospheric environment-elastic tensile stress interaction test method for the metal material according to claim 1, wherein in the step S2, the performance test period is 3 months, 6 months, 9 months or 12 months, during the test period, the elastic tensile stress is continuously and statically loaded on the sample, and the performance data of the test piece are respectively obtained before the test and after the end of each period.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211210191.5A CN115541483A (en) | 2022-09-30 | 2022-09-30 | Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211210191.5A CN115541483A (en) | 2022-09-30 | 2022-09-30 | Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115541483A true CN115541483A (en) | 2022-12-30 |
Family
ID=84730757
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211210191.5A Pending CN115541483A (en) | 2022-09-30 | 2022-09-30 | Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115541483A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116840137A (en) * | 2023-07-17 | 2023-10-03 | 鲁东大学 | Corrosion damage grading quantification method for aluminum alloy structural material |
-
2022
- 2022-09-30 CN CN202211210191.5A patent/CN115541483A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116840137A (en) * | 2023-07-17 | 2023-10-03 | 鲁东大学 | Corrosion damage grading quantification method for aluminum alloy structural material |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103969176A (en) | Method for testing seawater corrosion of low-alloy steel under stress state | |
| Yao et al. | Experimental study on generalized constitutive model of hull structural plate with multi-parameter pitting corrosion | |
| CN111504816A (en) | Marine atmospheric environment-tensile load dynamic loading coupling test and evaluation method | |
| CN110411934B (en) | Rapid assessment and prediction method for corrosion grade of aluminum alloy | |
| CN109596709B (en) | Detection method of fixed pressure container | |
| CN115541483A (en) | Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material | |
| Dostál et al. | Proportional monitoring of the acoustic emission in crypto-conditions | |
| CN105716946A (en) | Measuring method for predicting uniaxial constitutive relation of material by pressing cylindrical flat head in material | |
| Ramesh et al. | Health Monitoring of Structures by Using Non-Destructive Testing Methods | |
| CN110568083A (en) | acoustic emission detection method for online monitoring of corrosion fatigue damage of steel | |
| CN105891093A (en) | Detecting method of hydrogen induced cracking resisting performance of ferromagnetism metal material | |
| CN113884430A (en) | Comprehensive evaluation method and device for metal corrosion degree based on image recognition | |
| CN106769823B (en) | The method that the damaged in-service drag-line residual life of oversheath is assessed based on Defect Equivalent processing | |
| CN112816553B (en) | Heat-resistant steel aging grade evaluation method based on support vector machine | |
| CN113776963A (en) | Method for calculating fracture toughness by using spherical indentation method | |
| Tyutrin | Improving reliability of parts of mounted mower according to monitoring results by fatigue gauges from tin foil | |
| JP2008051513A (en) | Evaluation method of stress corrosion crack developing speed | |
| CN115683824B (en) | Fracture toughness testing device of test piece under corrosive environment | |
| CN114371082A (en) | Stress corrosion cracking monitoring and crack propagation rate evaluation device and test method | |
| Elboujdaini et al. | Hydrogen-induced cracking and effect of non-metallic inclusions in linepipe steels | |
| CN113252546A (en) | Method for rapidly evaluating corrosion fatigue of aluminum alloy in industrial atmospheric environment | |
| CN210923421U (en) | Device for evaluating stress corrosion cracking sensitivity of aging strengthening type aluminum alloy | |
| RU2376594C2 (en) | Magnetic method of detecting flaws in blades of turbo-machines made from cobalt alloys in mechanical loading conditions | |
| Zang et al. | Research and analysis of Giga-fatigue life of FV520B | |
| Dostál et al. | Accelerated corrosion and fatigue monitoring of aluminium alloy EN AW 7075 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |