In order to reveal tribo-magnetization phenomenon of ferromagnetic materials, a new apparatus which involved reciprocating friction tests of pin-on-block type under the geomagnetic field has been built to perform the tests. Based on the changes of the surface magnetic field of wear scar and the macroscopic and SEM analyses, it is concluded that tribo-magnetization of ferromagnetic materials is a two-stage process and the demarcation point of these two stages is the transition point of the friction forms. Furthermore, the shape and the position of wear scar can be estimated through measuring the surface magnetic field of wear scar.
