CN1278114C - Sample for measuring fatigue crack expansion rate in corrosion liquid and test method - Google Patents
Sample for measuring fatigue crack expansion rate in corrosion liquid and test method Download PDFInfo
- Publication number
- CN1278114C CN1278114C CN 200410060569 CN200410060569A CN1278114C CN 1278114 C CN1278114 C CN 1278114C CN 200410060569 CN200410060569 CN 200410060569 CN 200410060569 A CN200410060569 A CN 200410060569A CN 1278114 C CN1278114 C CN 1278114C
- Authority
- CN
- China
- Prior art keywords
- sample
- test
- fatigue crack
- crack
- corrosive liquid
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)
Abstract
The present invention relates to a sample and a test method for measuring the fatigue crack extending speed rate in the corrosive solution. The upper side of a crack extending face away from a sample is provided with a knife locking mouth of an electronic extensometer by an integrated design method. A great amount of test data is collected according to a control system of a testing machine, and the flexibility coefficient of the designed sample is figured out. Subsequently, the functional relation between the normalization crack length and the flexibility coefficient is established, so that when the test of the fatigue crack extending speed rate (da/dN) is carried out in the corrosive solution, the crack length can be detected automatically. Thus, the test method established according to the operation provides a guarantee for smoothly carrying out the test. Compared with measuring the fatigue crack extending speed rate (da/dN) in the corrosive solution through visual observation to measure the crack length in other domestic large units, the method of the present invention obviously enhances the precision for measuring the crack length and simultaneously greatly reduces the labor intensity. The safety design and the life evaluation of the ships used in the corrosive media can be more accurately carried out by the test results.
Description
Technical field:
The present invention relates to metallic material corrosion testing method technical field, a kind of sample and test method of measuring fatigue crack growth rate in the corrosive liquid.
Background technology:
The extensometer of specified standard compact tension specimen C (T) sample is installed the edge of a knife in the both sides of facing title about crack propagation in the GB/T6398-2000 of China (metal material fatigue crack growth rate test method) at present, when carrying out fatigue crack growth rate (da/dN) test in corrosive liquid, the situation that fatigue crack length is measured with flexibility method is only limited on horizontal fatigue tester carries out; If carry out this test on vertical fatigue tester, expensive extensometer (about 5000 U.S. dollars of import, homemade also wants thousands of yuans) tends to reduce its linearity, sensitivity or thoroughly damage because of the erosion that is subjected to corrosive liquid; And domestic most fatigue tester all is vertical, and therefore, when carrying out fatigue crack growth rate (da/dN) test in corrosive liquid, it almost is impossible measuring fatigue crack length with flexibility method.In light of this situation, when domestic most of units carry out this class test, generally pass through flexibility commercial measurement fatigue crack length without extensometer, but the spread scenarios of observing crackle by optical microscope with ocular estimate.But; the fatigue crack of metal material is often thinner; especially the fatigue crack of aldary, titanium alloy etc materials; in air, be not easy to observe very much clear; and owing to the corrosive liquid muddiness that usually can become because of the corrosion product of the metal material sample wherein that suspends; this makes with ocular estimate observation fatigue crack length more difficult, therefore is difficult to the precision that the assurance ocular estimate is observed fatigue crack length, and labour intensity is also very big.
At present, domestic relate to measure fatigue crack length in the experimental test field document seldom, particularly flexibility Study on Technology and the research that utilizes the flexibility technology to carry out the automatic context of detection of crack length under the corrosion environment are not seen as yet.
Summary of the invention:
In order to solve the problem of above-mentioned existence, the invention provides a kind of sample and test method of measuring fatigue crack growth rate in the corrosive liquid, this sample can make expensive electronic extensometer away from the corrosion liquid level, avoid extensometer to damage, thereby obtain test findings effectively reliably because of being subjected to the corrosive liquid erosion; Ocular estimate is measured fatigue crack length relatively, and this method can obviously improve the precision of measuring fatigue crack length, also reduces labour intensity simultaneously greatly.
The present invention adopts following technical scheme to realize:
The sample of fatigue crack growth rate in the described measurement corrosive liquid, at the upside away from the crack propagation face, the method for employing global design is provided with the edge of a knife that is installed of electronic extensometer; According to a large amount of test figure that the testing machine control system collects, utilize the Multitest testing software of import equipment, ask
The softness factor that solves designed sample is as follows:
| The softness factor symbol | C 0 | C 1 | C 2 | C 3 | C 4 | C 5 |
| Softness factor numerical value | 0.9927 | -4.8803 | 17.031 | -189.39 | 781.63 | -821.74 |
The sample softness factor solution procedure of fatigue crack growth rate is as follows in the described measurement corrosive liquid:
(1) measures thickness B, the width W of designed sample and the effective crack length a that adopts any method to cause, and test out the elastic modulus E of test material in advance;
(2) designed sample is adopted the method for Wire EDM cause crackle, cause once every a/W=0.025, and remeasure the crack length a of initiation, as used actual value;
(3) sample that will cause behind the crackle is contained on the testing machine, and electronic extensometer is installed on the knife-edge part of sample, zero clearing;
(4) sample behind the initiation crackle is slowly stretched in elastic range, need act on the load p on the sample, the deflection V of extensometer this moment with the higher point velocity collection of adopting;
(5) according to formula Ux=1/[(BEV
x/ P)
1/2+ 1] solves the dimensionless flexibility value Ux of sample;
(6) cause crackle at every turn after, all to solve a normalization crack length a/W value;
(7) when normalization crack length a/W=0.75, test can stop;
(8) (a/W Ux) carries out monobasic and increases progressively polynomial regression five times, and its regression coefficient just can be used as the softness factor of this sample to the data set of being tried to achieve;
(9) the polylith sample is undertaken by as above step, can obtain six softness factors of each sample respectively;
(10) softness factor to the polylith sample carries out the equalization processing, has just obtained final six softness factor C that find the solution
0, C
1, C
2, C
3, C
4, C
5
A kind of test method of measuring the fatigue crack growth rate of sample in the corrosive liquid, carry out according to the following step:
(1) mode of employing Wire EDM causes the initial crack of sample;
(2) softness factor of the designed sample that will solve is input in the test routine of finishing in advance;
(3) measure sample thickness, width parameter, and be input in the program of finishing in advance;
(4) corrosive cycle system, relevant sample jig and sample are connected with vertical fatigue tester;
(5) corrosive liquid is added the circulation system and be equipped with in the corrosion box of sample, the corrosive liquid in the circulation system is abundant, and the corrosive liquid in the corrosion box will guarantee to soak constantly the crack propagation face;
(6) electronic extensometer is installed on the knife-edge part of sample upside, and zero clearing;
(7) set each parameter of prefabricating fatigue crack, comprise the length of stress intensity factor range Δ K, control mode, employing frequency, waveform and prefabricating fatigue crack etc.;
(8) starting characteristics test machine, the beginning prefabricating fatigue crack is observed current crack extending length constantly, notes whole corrosive cycle system, in case corrosive liquid seepage and erosion test machine;
(9) prefabricated finish fatigue crack after, according to current result, parameters such as needed load range, stress ratio, frequency when setting test;
(10) starting characteristics test machine once more, the beginning official test;
(11) after the off-test,, simulate the fatigue crack growth rate curve and the equation thereof of test material, provide corresponding test report at last according to the expression-form of PARIS (Paris) empirical equation according to the test figure that is collected.
Owing to adopted technique scheme, the present invention to have following good effect:
The sample of in corrosive liquid (seawater, salt solution, river etc.), measuring fatigue crack growth rate (da/dN) that the present invention designs, the edge of a knife that is installed of electronic extensometer has been mentioned upside away from the crack propagation face, thereby solved on vertical fatigue tester when measuring fatigue crack length, expensive electronic extensometer often damages a difficult problem that causes test failure because of corrosive liquid corrodes with flexibility method.This sample also can be used on the horizontal fatigue tester.
The sample softness factor that utilization solves, set up the functional equation of normalization crack length and softness factor, theoretically for to lay a good foundation by flexibility commercial measurement fatigue crack length, thereby make that the detection of crack length has realized robotization when carrying out fatigue crack growth rate (da/dN) test in corrosive liquid, measuring fatigue crack growth rate (da/dN) with present domestic most unit in corrosive liquid compares with ocular estimate detection crack length, obviously improve the precision of measuring crack length, also greatly reduced labour intensity simultaneously.
In corrosive liquid, measure the design success of fatigue crack growth rate sample, the test method of correctly trying to achieve and being set up in view of the above of softness factor, provide assurance smoothly for such test.Utilize test findings, can carry out Safety Design and life appraisal to the boats and ships of being on active service in corrosive medium more accurately.
Description of drawings:
Fig. 1 is compact tension specimen C (T) assay maps of standard;
Fig. 2 measures designed assay maps in the sample of fatigue crack growth rate in the corrosive liquid and the test method;
Fig. 3 is fatigue crack growth rate (the da/dN)-Δ K curve map of compact tension specimen C (T) sample of standard;
Fig. 4 is fatigue crack growth rate (da/dN)-Δ K curve map of measuring the sample of fatigue crack growth rate in the corrosive liquid.
Embodiment:
1, measures the sample form of fatigue crack growth rate (da/dN) in the corrosive liquid
Compact tension specimen C (T) sample with standard in corrosive liquid carries out fatigue crack growth rate (da/dN) test, observe fatigue crack length with ocular estimate, one side can not guarantee that by the precision of the crack length that optical microscope is read labour intensity is also quite big on the other hand.As shown in fig. 1, the extensometer of this sample is installed the edge of a knife (1. locating) in the both sides of facing title about crack propagation.During fatigue crack growth rate (da/dN) in vertical torture test airborne measurements corrosive liquid (2. locate is corrosion liquid level), expensive extensometer tends to be subjected to the erosion of corrosive liquid.If the edge of a knife that is installed of extensometer is moved to the upside of crack propagation face, just extensometer that at first can the guaranteed price costliness is not etched.In addition, if can solve the softness factor of this sample, just can adopt the flexibility technology to measure fatigue crack length in the corrosive liquid, so just can guarantee the precision that crack length is measured, also can reduce a large amount of hard-workings of being paid when measuring simultaneously greatly with ocular estimate.
So, on the basis of the compact tension specimen C of standard (T) sample, we have designed the sample of fatigue crack growth rate (da/dN) in the measurement corrosive liquid, as shown in Figure 2, the method design that the edge of a knife that is installed (3. locating) of electronic extensometer adopts global design is away from the upside of crack propagation face, like this, solved the difficult problem that expensive electronic extensometer is corroded by corrosive liquid (4. being the corrosion liquid level) on the one hand, on the other hand also for to lay the foundation with flexibility commercial measurement fatigue crack length.A large amount of test figures such as the normalization crack length that we collect according to the testing machine control system, the dimensionless flexibility of sample, unknown parameter softness factor, on the basis of tight reasoning and practice, make full use of the functional characteristics of the Multitest testing software of import equipment, solved the softness factor of designed sample.The characteristic feature of designed sample is: the electronic extensometer that will be used for measuring indirectly fatigue crack length is installed method design that the edge of a knife adopts the globality design away from the upside of crack propagation face, extensometer that on the one hand can the guaranteed price costliness in process of the test is away from the corrosion liquid level like this, avoid in the process of measuring fatigue crack length, reducing its linearity because of being subjected to the corrosive liquid erosion, sensitivity or the possibility of thoroughly damaging, can guarantee preferably also that on the other hand extensometer can not make test failure because of coming off in entire test, also be convenient to charge and discharge operations simultaneously.The design success of this sample provides possibility for carry out detecting crack length automatically when fatigue crack growth rate (da/dN) is tested in corrosive liquid.
2, the softness factor of designed sample
Through a large amount of reasoning and verification experimental verification, softness factor precision height, the good reliability of the sample of finding the solution, has practicality widely: all identical with designed sample form, as to be in proportion samples that can be applied to different metal materials, various sample size.Utilize six sample softness factors that solved, set up the functional equation of normalization crack length and softness factor, theoretically for to lay a good foundation with flexibility commercial measurement fatigue crack length, thus when in corrosive liquid, carrying out fatigue crack growth rate (da/dN) test the automatic measurement of fatigue crack length provide may.The control system of testing machine is collected data necessary such as the load that acts on the sample, extensometer opening displacement be applied to pass through the computer program that the theoretical formula of asking is write, just can calculate the extension length of the current crackle of sample at any time automatically, and can be presented on the computer desktop constantly.Through calculating and handling, just can obtain the fatigue crack growth rate of test material in corrosive liquid at last.Trying to achieve of designed sample softness factor makes that the detection of crack length has realized in the robotization when carrying out fatigue crack growth rate (da/dN) test in corrosive liquid, also obviously improved the measuring accuracy of crack length, greatly reduces labour intensity.
The softness factor of invention design sample is as follows:
| The softness factor symbol | C 0 | C 1 | C 2 | C 3 | C 4 | C 5 |
| Softness factor numerical value | 0.9927 | -4.8803 | 17.031 | -189.39 | 781.63 | -821.74 |
3, the solution procedure of designed sample softness factor
(1) measures thickness B, the width W of designed sample and the effective crack length a that adopts any method to cause, and test out the elastic modulus E of test material in advance;
(2) designed sample is adopted the method for Wire EDM cause crackle, cause once every a/W=0.025, and remeasure the crack length a of initiation, as used actual value;
(3) sample that will cause behind the crackle is contained on the testing machine, and electronic extensometer is installed on the knife-edge part of sample, zero clearing;
(4) sample behind the initiation crackle is slowly stretched in elastic range, need adopt point velocity (such as 100 data points/sec) collection acts on the load p on the sample, the deflection V of extensometer this moment with higher;
(5) according to formula Ux=1/[(BEV
x/ P)
1/2+ 1] solves the dimensionless flexibility value Ux of sample;
(6) cause crackle at every turn after, all to solve a normalization crack length a/W value;
(7) (should be worth generally during official test and can not surpass 0.70) when normalization crack length a/W=0.75, test can stop;
(8) (a/W Ux) carries out monobasic and increases progressively polynomial regression five times, and its regression coefficient just can be used as the softness factor of this sample to the data set of being tried to achieve;
(9) the polylith sample is undertaken by as above step, can obtain six softness factors of each sample respectively;
(10) softness factor to the polylith sample carries out the equalization processing, has just obtained final six softness factor C that find the solution
0, C
1, C
2, C
3, C
4, C
5
4, test method
Utilize designed sample and the softness factor thereof that goes out, just can finish fatigue crack growth rate (da/dN) test of in corrosive liquid, carrying out according to the following step:
(1) mode of employing Wire EDM causes the initial crack of sample;
(2) softness factor of the designed sample that will solve is input in the test routine of finishing in advance;
(3) measure parameters such as sample thickness, width, and be input in the program of finishing in advance;
(4) corrosive cycle system, relevant sample jig and sample are connected with vertical fatigue tester;
(5) corrosive liquid is added the circulation system and be equipped with in the corrosion box of sample, the corrosive liquid in the circulation system is abundant, and the corrosive liquid in the corrosion box will guarantee to soak constantly the crack propagation face;
(6) electronic extensometer is installed on the knife-edge part of sample upside;
(7) set each parameter of prefabricating fatigue crack, comprise the length of stress intensity factor range Δ K, control mode, employing frequency, waveform and prefabricating fatigue crack etc.;
(8) starting characteristics test machine, the beginning prefabricating fatigue crack is observed current crack extending length constantly, notes whole corrosive cycle system, in case corrosive liquid seepage and erosion test machine;
(9) prefabricated finish fatigue crack after, according to current result, parameters such as needed load range, stress ratio, frequency when setting test;
(10) starting characteristics test machine once more, the beginning official test;
(11) after the off-test,, simulate the fatigue crack growth rate curve and the equation thereof of test material, provide corresponding test report at last according to the expression-form of PARIS (Paris) empirical equation according to the test figure that is collected.
Inventing the sample form of design can see from us, and this sample can undoubtedly be used in the torture test in the corrosive liquid and guarantee that the electronic extensometer liquid that is not corroded corrodes.In order to verify the correctness and the feasibility of designed sample softness factor and test method, we have selected a kind of structure steel material, and we invent the sample of design to be processed into the compact tensile specimen of one group of standard and one group.Since the fatigue crack growth rate that the compact tensile specimen of standard can't the experiment with measuring material in corrosive liquid on vertical testing machine, and the fatigue crack growth rate of metal material in air and in corrosive liquid often differs greatly.Therefore, we think, if in air, tested the fatigue crack growth rate (da/dN) of test material with the flexibility technology with the compact tensile specimen of standard, and then invent the sample of design and softness factor adopts same test condition to test with us, because test material is the same, if the consistance of test result is fine, just can show that sample and test method that we invent are correct.
Testing equipment is vertical MTS810 electo hydraulic servocontrolled fatigue testing machine.
Adopt above-mentioned test method step to test.
The test condition that adopts is as follows:
Test load range delta P=12.0KN, stress ratio R=0.1, waveform are sinusoidal wave, and frequency f=10Hz tests in the air at room temperature.
Test findings (comprising da/dN-Δ K curve map and equation thereof) is as shown in Fig. 3 and Fig. 4, and from Fig. 3 and Fig. 4 as seen, the distribution of the data set of two kinds of samples (da/dN, Δ K) is just the same.Consider the structural homogenity of test material and the mismachining tolerance of every sample, the test material that obtains crack growth rate of (corresponding different softness factors) under two kinds of various sample forms is consistent.This fully shows, the sample of the fatigue crack growth rate of metal material is practical in the measurement corrosive liquid of our designed invention, and softness factor is that the test method of being set up has reliability and feasibility reliably.
Claims (3)
1, a kind of sample of measuring fatigue crack growth rate in the corrosive liquid is characterized in that: described sample, adopt the method for global design to be provided with the edge of a knife that is installed of electronic extensometer at the upside away from the crack propagation face; According to a large amount of test figure that the testing machine control system collects, utilize the Multitest testing software of import equipment, the softness factor that solves designed sample is as follows:
The softness factor symbol C
0 C
1 C
2 C
3 C
4 C
5
Softness factor numerical value 0.9927 -4.8803 17.031 -189.39 781.63 -821.74
2, the sample of fatigue crack growth rate in the measurement corrosive liquid as claimed in claim 1, it is characterized in that: the solution procedure of this sample softness factor is as follows:
(1) measures thickness B, the width W of designed sample and the effective crack length a that adopts any method to cause, and test out the elastic modulus E of test material in advance;
(2) designed sample is adopted the method for Wire EDM cause crackle, cause once every a/W=0.025, and remeasure the crack length a of initiation, as used actual value;
(3) sample that will cause behind the crackle is contained on the testing machine, and electronic extensometer is installed on the knife-edge part of sample, zero clearing;
(4) sample behind the initiation crackle is slowly stretched in elastic range, need act on the load p on the sample, the deflection V of extensometer this moment with the higher point velocity collection of adopting;
(5) according to formula Ux=1/[(BEV
x/ P)
1/2+ 1] solves the dimensionless flexibility value Ux of sample;
(6) cause crackle at every turn after, all to solve a normalization crack length a/W value;
(7) when normalization crack length a/W=0.75, test can stop;
(8) (a/W Ux) carries out monobasic and increases progressively polynomial regression five times, and its regression coefficient just can be used as the softness factor of this sample to the data set of being tried to achieve;
(9) the polylith sample is undertaken by as above step, can obtain six softness factors of each sample respectively;
(10) softness factor to the polylith sample carries out the equalization processing, has just obtained final six softness factor C that find the solution
0, C
1, C
2, C
3, C
4, C
5
3, a kind of test method of measuring the fatigue crack growth rate of sample in the corrosive liquid, it is characterized in that: this test method is carried out according to the following step:
(1) mode of employing Wire EDM causes the initial crack of sample;
(2) softness factor of the designed sample that will solve is input in the test routine of finishing in advance;
(3) measure sample thickness, width parameter, and be input in the program of finishing in advance;
(4) corrosive cycle system, relevant sample jig and sample are connected with vertical fatigue tester;
(5) corrosive liquid is added the circulation system and be equipped with in the corrosion box of sample, the corrosive liquid in the circulation system is abundant, and the corrosive liquid in the corrosion box will guarantee to soak constantly the crack propagation face;
(6) electronic extensometer is installed on the knife-edge part of sample upside, zero clearing;
(7) set each parameter of prefabricating fatigue crack, comprise the length of stress intensity factor range Δ K, control mode, employing frequency, waveform and prefabricating fatigue crack;
(8) starting characteristics test machine, the beginning prefabricating fatigue crack is observed current crack extending length constantly, notes whole corrosive cycle system, in case corrosive liquid seepage and erosion test machine;
(9) prefabricated finish fatigue crack after, according to current result, the parameter of needed load range, stress ratio, frequency when setting test;
(10) starting characteristics test machine once more, the beginning official test;
(11) after the off-test,, simulate the fatigue crack growth rate curve and the equation thereof of test material, provide corresponding test report at last according to the expression-form of PARIS (Paris) empirical equation according to the test figure that is collected.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410060569 CN1278114C (en) | 2004-10-14 | 2004-10-14 | Sample for measuring fatigue crack expansion rate in corrosion liquid and test method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200410060569 CN1278114C (en) | 2004-10-14 | 2004-10-14 | Sample for measuring fatigue crack expansion rate in corrosion liquid and test method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1587988A CN1587988A (en) | 2005-03-02 |
| CN1278114C true CN1278114C (en) | 2006-10-04 |
Family
ID=34603486
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200410060569 Expired - Fee Related CN1278114C (en) | 2004-10-14 | 2004-10-14 | Sample for measuring fatigue crack expansion rate in corrosion liquid and test method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1278114C (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102426137B (en) * | 2011-08-31 | 2013-06-05 | 中国船舶重工集团公司第七二五研究所 | Testing and measuring method capable of axially loading low cycle fatigue crack initiation |
| FR2995080B1 (en) * | 2012-09-04 | 2015-10-23 | Snecma | METHOD FOR HIGH-FREQUENCY DETERMINATION OF FATURE NON-PROPAGATION FATIGUE THRESHOLD |
| CN103884610B (en) * | 2012-12-21 | 2016-06-29 | 中国直升机设计研究所 | A kind of composite II type cracking threshold and S-N curve determination method |
| CN103439202A (en) * | 2013-08-19 | 2013-12-11 | 北京航空航天大学 | System for testing fatigue in corrosion environment |
| CN103439199A (en) * | 2013-08-19 | 2013-12-11 | 北京航空航天大学 | System for testing fatigue crack propagation in corrosion environment |
| CN104404582A (en) * | 2014-11-19 | 2015-03-11 | 中国航空工业集团公司沈阳飞机设计研究所 | Method for optimizing high-corrosion resistance cadmium titanium plating layers of ultrahigh-strength steel |
| CN104458562B (en) * | 2014-11-28 | 2017-02-22 | 中国航空工业集团公司北京航空材料研究院 | Measuring method for opening stress of crack |
| CN110376062A (en) * | 2019-07-22 | 2019-10-25 | 中国航发沈阳发动机研究所 | A kind of resonant fatigue test crackle pre-setting method |
| CN110987634A (en) * | 2019-11-15 | 2020-04-10 | 河海大学 | Test device and test method for hydraulic fracture of gravel-doped core wall |
| CN111665132A (en) * | 2020-06-17 | 2020-09-15 | 天津大学 | Method for measuring fatigue crack propagation of opening corner |
-
2004
- 2004-10-14 CN CN 200410060569 patent/CN1278114C/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| CN1587988A (en) | 2005-03-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1278114C (en) | Sample for measuring fatigue crack expansion rate in corrosion liquid and test method | |
| EP1333277A3 (en) | Method and apparatus for investigating pipes with ultrasonic phased array sensors | |
| JP2001153865A (en) | Evaluating method and device for damage of metallic material | |
| CN1392400A (en) | Non-destructive testing method and device for mechanical property of brittle material | |
| RU2582911C1 (en) | Method of testing pipe steels for stress corrosion cracking | |
| CN101126799A (en) | Method for monitoring fatigue damage using ferromagnetic materials surface stray magnetic field signal | |
| CN114323994A (en) | Method for testing fatigue crack propagation rate of three-point bending sample in T-shaped wave load-holding test | |
| CN109443671B (en) | A kind of monitoring method of high-speed train body key position remaining life | |
| CN1766550A (en) | Method for evaluating critical stress intensity and sensitive factor of stress corrosion cracking for oil well pipe | |
| CN111678990B (en) | Ultrasonic fatigue crack propagation rate measuring method based on natural frequency | |
| CN112945772A (en) | Engineering rock body mechanical property analysis method under water rock circulation | |
| CN115541483A (en) | Method for testing interaction between marine atmospheric environment and elastic tensile stress of metal material | |
| JPH06249828A (en) | Detection of carbide in low alloy steel by electrochemical polarization method | |
| Karuskevich et al. | Estimation of the accumulated fatigue damage by saturation and fractal dimension of the deformation relief. | |
| RU2820157C1 (en) | Improved method for cyclic testing of full-thickness samples of main pipelines for stress corrosion cracking | |
| Khalate et al. | Detection of cracks present in composite cantilever beam by vibration analysis technique | |
| JP2003294716A (en) | Inspection method of turbine | |
| CN113655119B (en) | Water immersion type ultrasonic device for evaluating corrosion resistance of aluminum alloy material and using method thereof | |
| Shell et al. | Correlation of residual fatigue life with quantified NDE measurements | |
| CN113138157B (en) | Nondestructive evaluation method for stress corrosion sensitivity of aluminum alloy extruded section | |
| CN115406820A (en) | Indoor accelerated environmental damage detection and evaluation method for aluminum alloy threaded part | |
| CN216132992U (en) | Ultrasonic phased array detection reference block for petroleum high-pressure test elbow | |
| CN109459473B (en) | Material passivation film damage repair in-situ monitoring device | |
| RU2008125112A (en) | METHODS, SYSTEMS AND COMPUTER SOFTWARE PRODUCTS FOR STRUCTURE DIAGNOSTICS | |
| JP5176142B2 (en) | Die bonding film surface inspection method and surface inspection system |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| EE01 | Entry into force of recordation of patent licensing contract |
Assignee: Luoyang Qiwei Anti-Corrosion Engineering Material Co., Ltd. Assignor: No.725 Inst. China Shipping Heavy Industry Group Corp. Contract fulfillment period: 2008.8.12 to 2016.8.11 contract change Contract record no.: 2008410000032 Denomination of invention: Sample for measuring fatigue crack expansion rate in corrosion liquid and test method Granted publication date: 20061004 License type: Exclusive license Record date: 20081112 |
|
| LIC | Patent licence contract for exploitation submitted for record |
Free format text: EXCLUSIVE LICENSE; TIME LIMIT OF IMPLEMENTING CONTACT: 2008.8.12 TO 2016.8.11; CHANGE OF CONTRACT Name of requester: LUOYANG QIWEI CORROSION PROTECTION ENGINEERING MAT Effective date: 20081112 |
|
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20061004 Termination date: 20091116 |