Hardness monitoring and material identification testing

The magneto-inductive method

The magneto-inductive test is a non-destructive method for material characterization. This method is used to test components for their material properties in order to avoid confusion or establish various heat treatment states.

Typical applications:

  • Alloy composition
  • Heat treatment (e.g. hardening, quenching and tempering, normalizing, annealing)
  • Micro-structure (e.g. ferrite, martensite, cementite, austenite, perlite, bainite)
  • Tensile and compressive strength, deformation and stress states
  • Hardness penetration depth and case depth


Testing for material properties

To test for material properties, the specimens usually pass through a full feed-through coil. For special applications, local testing for surface hardness for example, probes adapted for the specimen concerned are used. The test stress recorded by the sensor results from the magnetic and electrical properties of the specimen, the stress value being plotted as a stress value. As part of the calibration process, a sorting threshold is automatically formed from the statistical evaluation of multiple measured values. The subsequent series test involves comparing all other measuring points with the specified tolerance thresholds. The workpieces are sorted depending on the test result.