Development of Magnetic Memory Testing System Used on Defect Detection of Drill Pipe

2010 ◽  
Author(s):  
Wenpei Zheng ◽  
Jianchun Fan ◽  
Laibin Zhang ◽  
Dong Wen
Keyword(s):  
Stress Concentration ◽  
Nondestructive Testing ◽  
Defect Detection ◽  
Drill Pipe ◽  
Ferromagnetic Material ◽  
Oil Field ◽  
Testing System ◽  
Magnetic Memory ◽  
Memory Testing ◽  
Testing Technology

Drill pipe is used in well drilling in oil field. Under the force of tubular columns and pressure of drilling fluids, the drill pipe usually fails in long-term service, which consequently leads to accidents, such as drill pipe twisting off, and causes stagnation of production. So it’s especially necessary to detect defects in drill pipe in time. Traditional nondestructive testing methods, for example, magnetic flux leakage, eddy current and ultrasound, can only detect already formed defects. They do not help detect and evaluate stress concentration zones, which tends to develop into defects. Magnetic memory testing technology is a newly developed nondestructive testing technology. Under the exciting of the magnetic field of the earth, the magnetic status will change in stress concentration zones of ferromagnetic material. Location and study of the stress concentration zones will forecast the defects of ferromagnetic material. Magnetic memory testing system used on defect detection for drill pipe is developed based on this technology. Composition and function of the system is introduced, and application effect is shown. This system will play important part in detection and evaluation for drill pipe in oil field.

Magnetic crawler climbing detection robot basing on metal magnetic memory testing technology

2020 ◽  
Vol 125 ◽  
pp. 103439 ◽  
Author(s):  
Fumin Gao ◽  
JianChun Fan ◽  
Laibin Zhang ◽  
Jiankang Jiang ◽  
Shoujie He
Keyword(s):  
Magnetic Memory ◽  
Memory Testing ◽  
Metal Magnetic Memory ◽  
Testing Technology ◽  
Metal Magnetic Memory Testing

Eddy Current and Metal Magnetic Memory Testing Nondestructive Evaluation for Superficial Defects of Old Cylinder Barrel

2016 ◽  
Vol 850 ◽  
pp. 107-112
Author(s):  
Chang Liang Shi ◽  
Shi Yun Dong ◽  
Wei Xue Tang ◽  
Hao Zhan
Keyword(s):  
Stress Concentration ◽  
Eddy Current ◽  
Eddy Current Testing ◽  
Magnetic Memory ◽  
Memory Testing ◽  
Metal Magnetic Memory ◽  
Current Testing ◽  
Cylinder Barrel ◽  
Metal Magnetic Memory Testing

Eddy current testing and metal magnetic memory testing, cooperated with special testing devices, were applied to detect the superficial defects of old cylinder barrel. It was indicated that there were three types of the signals, which were non-defect signals, discontinuous peak signals and continuous peak signals. Non-defect signals indicated that there was no defect in cylinder barrel, and the discontinuous peak signals denoted that there was circumferential cracking, and the continuous peak signals showed that there was longitudinal cracking in the surface of cylinder barrel. The amplitude of eddy current testing signals characterizes the depth of cracking, and the gradient of magnetic signals descript the degree of stress concentration. The method mentioned above detects the cracking and stress concentration in the superficial coat of old cylinder barrel, which effectively guarantee the quality of automobile cylinder.

Analysis of Metal Magnetic Memory Testing Technology

2012 ◽  
Vol 503-504 ◽  
pp. 1623-1626
Author(s):  
Guo Min Lin ◽  
Hang Yun Lin ◽  
Kai Dong
Keyword(s):  
Memory Effect ◽  
Magnetic Memory ◽  
Memory Testing ◽  
Metal Magnetic Memory ◽  
Testing Technology ◽  
Metal Magnetic Memory Testing

The magnetic memory effect and the principle of magnetic memory testing are described; The phenomenon of the magnetostriction is discussed. An instance is used with detail to analysis of the effect and mechanism of metal magnetic memory testing technology. Some opinions about the further work needs to be done in this area are given finally.

Design and Application of MMM System for Welding Residual Stress Test

2012 ◽  
Vol 566 ◽  
pp. 534-537
Author(s):  
Hai Yan Xing ◽  
Ping Qin ◽  
Yan Min Lou
Keyword(s):  
Residual Stress ◽  
Stress Concentration ◽  
Stress Test ◽  
Object Oriented Programming ◽  
Welding Residual Stress ◽  
Testing System ◽  
Magnetic Memory ◽  
X Ray ◽  
Analysis And Evaluation ◽  
Examination Result

In order to apply metal magnetic memory (MMM) technology to welding residual stress testing, the MMM hardware and software system is designed. The software subsystem is based on object-oriented programming and the hardware subsystem is portable. The MMM system can test the welded joint residual stress distribution, residual stress concentration zones and defects at workshop. Moreover, the MMM testing system can output data to a computer not only for automatic evaluation but also for further analysis and evaluation with expert intervention. According to the trend of the MMM characteristic, the welding residual stress concentration and defects can be detected and evaluated. The field X-ray examination result is consistent with the result of the MMM testing system, which has proved the accuracy and engineering practicality of the MMM testing system.

scholarly journals Magnetic Memory Inspection of an Overhead Crane Girder – Experimental Verification

2019 ◽  
Vol 26 (2) ◽  
pp. 69-76
Author(s):  
Agnieszka Kosoń-Schab ◽  
Jarosław Smoczek ◽  
Janusz Szpytko
Keyword(s):  
Stress Concentration ◽  
Magnetic Flux ◽  
Material Handling ◽  
Impact Load ◽  
Ferromagnetic Material ◽  
The Self ◽  
Magnetic Flux Leakage ◽  
Magnetic Memory ◽  
Earth Magnetic Field ◽  
Flux Leakage

Abstract The safety and efficiency of material handling systems involve periodical inspections and evaluation of transportation device technical conditions. That is particularly important in case of industrial cranes, since they are subjected to a large impact load and mechanical stresses acting on the crane's structure and equipment. The paper considers the possibility of a crane structure inspection using the metal magnetic memory (MMM) method. As an advanced non-destructive technique, this method can be employed for inspection of crane structure during operation, which leads to reduce the down time costs and increase the safety confidence in the monitoring process. The MMM technique is effective for early identification of the possible defect location and detecting the micro-damage in ferromagnetic structures through detecting the stress concentration areas. The basic principle of MMM method is the self-magnetic flux leakage signal that correlates with the degree of stress concentration. This method allows detecting early damage of ferromagnetic material through performing measurement in the earth magnetic field, without the use of a special magnetizing device. The paper presents the experimental results carried out on the double-girder overhead travelling crane with hoisting capacity 1000 kg. The influence of the load variation and duration time on the intensity of the self-magnetic flux leakage signal is analysed and discussed.

Characterization of Crack Initiation Life in Ferromagnetic Material by Metal Magnetic Memory Testing

2015 ◽  
Vol 817 ◽  
pp. 791-796
Author(s):  
Chang Liang Shi ◽  
Wei Xue Tang ◽  
Hao Zhan ◽  
Shi Yun Dong
Keyword(s):  
Magnetic Field ◽  
Crack Initiation ◽  
Normal Component ◽  
Ferromagnetic Material ◽  
Magnetic Memory ◽  
Memory Testing ◽  
Metal Magnetic Memory ◽  
Numerical Fitting ◽  
Crack Initiation Life ◽  
Metal Magnetic Memory Testing

In the geomagnetic field, stress can induce spontaneous magnetic signals in ferromagnetic materials, the method, named metal magnetic memory testing, can be potentially applied in estimating the fatigue life. In this paper, the normal component of magnetic field, Hp (y), was measured during dynamic tension test on the surfaces of ferromagnetic specimens with stress concentration factor of 5. The results indicated that the gradient of magnetic field intensity, K, was the key parameter to characterize crack initiation life. Then the numerical fitting of K and fatigue cycles were done under three level loads, 568.7MPa, 698.8MPa and 864.4MPa, meanwhile, a simple model was derived.

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