Magnetism magnetic particles

Magnetism, Magnetic Particles, and Magnetic Particulate Films... 

The suggested method is appropriately implemented at the practice. The cost and working hours of unit measurement of it is less than of any alternative method of destructive test and with respect to the authenticity inspection of Stress-Deformation the given method is inferior only to destructive testing. The method was successfully implemented while evaluation of service life of main pipe-lines sections and pressure vessels as well. Data of method and instrument are used as official data equally with ultrasonic, radiation, magnetic particles methods, adding them by the previously non available information about " fatigue " metalwork structure. 

Nondestructive testing techniques for welded joints usually include visual, radiographic, magnetic particle, liquid penetrant, and ultrasonic testing methods. Of interest in this paper is the radiographic testing (RT) technique. 

Surface Crack Detection Using Magnetic Particle Techniques and Penetrant Inspection Method. 

Due to the well known human shortcomings the probability of finding flaws using Magnetic Particle Inspection (MPI) or Liquid Penetrant Inspection (LPI) can be restricted to only 60-85% and the inspection reproducablity is difficult. 

The great variety of inspection applications required the QAP system to perform relative measurements in judgeing certain conditions and not to restrict the user to dictated inspection conditions. One important example for MPI is for example the decision whether the magnetic particle suspension can be used or has to be changed. 

Magnetic Particle inspection Liquid Penetrant Inspection... 

The condition of the magnetic particle suspension is controlled by an automated ASTM-bulb. The bulb is connected to the currently used Magentic particle suspension tank by a bypass, so the suspension in use is flowing through the bulb too. In user defined periods a valve is closed and the Magentic particle suspension remained into the bulb is analysed. The automatic bulb has the ability to measure the extinction and transmission of the suspension related to the time (Figure 1, Figure 2)... 

The system compares its own values for good and a bad magnetic particle suspensions with the actually measured values. The system values are stored in the form of reference curves for a fresh MP-suspension used on the machine and the used MP-suspension which has to be changed. 

Optimization of Parameters Control and Characterization Defects by Magnetic Particles. 

Magnetic particles is one of the most used nondestructive testing techniques in industry. It allows detection and localization of surfacic and subsurfacic defects of ferromagnetic pieces by making conspicuous leakage fields by a magnetic developer. 

Our method consists in the use of all magnetic particles testing techniques and to bear in mind the physical approach and the different processes combinations. 

Automated Magnetic Particle Testing of Truck Spindles. 

Magnetic Particle Inspection was developed by Professor AW de Forest in 1928. De Forest and Doane started the company Magnaflux, the name of which became synonymous with MPI. 

Some Aspects on the Reliability of Magnetic Particle Testing. 

The nominal inclination of the surface against the horizontal was 15°. Experiments indicate a relatively constant contrast, because Li and Ls decreasing proprtionally with increasing inclination. RI = -0.1 The magnetic particle content was reduced from 0.5 g/l to 0.25 g/1 This reduction seems realistic resulting in RP = -0.1... 

With the objective determination of the visibilitity of magnetic particle indications quantitative researches on the influence of the inspection parameters will be possible. The first part deals with the type testing of detection media which is as well on the course of adoption for type testing of liquid penetrant systems (prEN 751-2). 

When comparing the magnetic particle- and penetrant inspection with other visual methods it appears that our viewing eonditions are not so bad, compared with other methods. In radio-graphie the contrast on the film is mueh lower. In ultrasonies and eddy current the presentation times on the screen is shorter and the contrast is lower. 

M. Stadthaus Evaluation of the viewing Conditions for fluorescent Magnetic Particle-and Penetrant Testing, INSIGHT Dez. 1997... 

Detailed view of the magnetic particle testing device... 

Nondestmctive evaluation, also termed nondestmctive testing or nondestmctive inspection, is extensively used in weld testing (14). Nondestmctive tests do no impair the serviceabiUty of the material or component under stress. The most widely used tests for evaluation of welds are Hquid penetrant, magnetic particle, ultrasonics, and radiography. Acoustic-emission tests are increasingly used. Nondestmctive tests detect and characterize, in terms of size, shape, and location, the various types of weld discontinuities that can occur. 

Defects such as hot tears or laps, quench cracks, localized overheating during stress rehef, and corrosion may occur during the tubemaking process (154). Magnetic particle, ultrasonic, and visual inspection techniques are used to ensure that relatively few tubes enter service with significant defects. 

---