Study and characterization of quenched and tempered ferromagnetic steels by magnetic BARKHAUSEN noise technique

Abstract

The aim of this work is to study the microstructures of quenched and tempered steels nondestructively using the Magnetic BARKHAUZEN Noise technique. Two types of samples were prepared from X70 steel bars. All samples were heated by direct quenching (DQ) at 760 °C for 0.5 hours. The quenched samples were then tempered at various temperatures between 300°C , 410°C and 500°C. Formation of the desired microstructures was demonstrated by metallographic examinations and hardness measurements. In all specimens, the position, shape, and amplitude of the BARKHAUZEN signals were described using a MikroMach system.