Magnetic Particle Testing (MT)

 Magnetic particle examination (MT) is a very popular, low-cost method to perform nondestructive examination (NDE) of ferromagnetic material. Ferromagnetic is defined in ASME Section V as “a term applied to materials that can be magnetized or strongly attracted by a magnetic field.” MT is an NDE method that checks for surface discontinuities but can also reveal discontinuities slightly below the surface. 

There are many different techniques and combinations of techniques of MT. The ASME Boiler and Pressure Vessel Code, Section V, Article 7, recognizes five different techniques of magnetization: 

▪ Prod technique 

▪ Longitudinal magnetization technique 

▪ Circular magnetization technique

▪ Yoke technique

▪ Multidirectional magnetization technique