QUALITY CONTROL OF INTERCRITICALLY ANNEALED DUAL PHASE STEEL PARTS BY BARKHAUSEN SIGNALS NON-DESTRUCTIVE METHOD

Dual phase steels (DPS) have a composite type microstructure and they take advantages of combination of the hard second phase (martensite) and the ductile matrix (ferrite). This combination could enhance thestrength and ductility. In this regard, martensite phase play a decisive role in determination of DPSproperties and phase percentage of it is a key factor for quality control of heat treated parts. In order to determination of martensite percentage, present study uses Barkhausen signals, nondestructively. Comparison of test results showed a very good agreement between the metallographic observation andBarkhausen study. In general, an increase in the percentage of martensite results in the decrease indomain wall motion and, therefore, magnetic Barkhausen signals increase. Therefore, results showed the potential of this NDT method to separate the good heat treated samples and the bad ones

Keywords:

Barkhausen signal , Dual phase steel , Intercritical annealing heat treatment , Martensite phase percentage , Non-destructive testing