Characterizing microstructural changes in ferritic steels by positron annihilation spectroscopy: Studies on modified 9Cr-1Mo steel

► Positron lifetime technique probing microstructure of ferritic/martensitic steels. ► Correlation between positron lifetime, ultrasonic and hardness. ► Complementary nature of positron annihilation spectroscopy in probing defects. ► Distinguishing precipitation stages by positron annihilation spectroscopy.