MAGNETIC PARTICLE INSPECTION - MT

THE COMPLEXITY AND EXPENSE OF TODAY'S MACHINES, EQUIPMENT AND TOOLS DICTATE THE USE OF FABRICATION AND TESTING PROCEDURES THAT WILL ENSURE MAXIMUM RELIABILITY. NONDESTRUCTIVE TESTING PROVIDES MANY OF THESE PROCEDURES. OF THE NUMBER OF NONDESTRUCTIVE TESTING PROCEDURES AVAILABLE, "MAGNETIC INSPECTION" IS ONE THAT IS WIDELY USED.

INDUSTRIAL APPLICATIONS...
Because magnetization of certain metals is possible, small particles that are attracted to magnetic fields are applied to the surface of the test object after or during induction of a magnetic field, thereby detecting certain discontinuities which are present in the material. Since Magnetic Particle Inspection is capable of revealing discontinuities (variations in material composition) economically, it is one of the most used, nondestructive test methods. However, this test method is limited to disclosing only those discontinuities that are at or near the surface.

TEST PROCEDURES...
Approved procedures for "MT" are formulated from analysis of the test specimen or article, review of its past history, experience on like or similar specimens, and information available concerning discontinuities in similar articles. It is the responsibility of personnel conducting the test to ensure that test procedures are adequately performed, and that the test objective is accomplished.

TEST OBJECTIVE...
The test objective of Magnetic Particle Inspection is to ensure product reliability by providing a means of:

• a. Obtaining a visual image related to a discontinuity in or at the surface of the material being tested.
• b. Disclosing the nature of the discontinuity without impairing the material being tested.
• c. Separating acceptable and unacceptable material in accordance with predetermined standards.

PERSONNEL...
It is imperative that personnel responsible for "MT" be trained and highly qualified with a technical understanding of the test equipment and materials, the item under test, and the test procedures. To make optimum use of "MT", personnel conducting tests must continually keep abreast of new developments. There is no substitute for experience and knowledge. All Halkin personnel are certified in compliance with ASNT and ASTM guidelines, and Halkin's Quality Assurance Manual is available for your review on request.

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