Acta Metallurgica Sinica (English Letters) ›› 2015, Vol. 28 ›› Issue (3): 295-301.DOI: 10.1007/s40195-014-0196-2

• Orginal Article • Previous Articles     Next Articles

Comparing the Fatigue and Corrosion Behavior of Nanograin and Coarse-Grain IF Steels

A. Chabok(), K. Dehghani, M. Ahmadi Jazani   

  1. Mining and Metallurgical Engineering Department, Amirkabir University of Technology, Tehran, Iran
  • Received:2014-02-17 Revised:2014-06-24 Online:2015-01-07 Published:2015-07-23

Abstract:

In the present work, a nanograin layer of about 150 µm thick was formed on the surface of an interstitial-free (IF) steel via friction stir processing. Then, the fatigue and corrosion behaviors of IF steel with nanograin layer were compared with that of coarse-structure counterpart. More than threefold increase in the hardness was observed due to the formation of nanograin layer. The size of nanograins in the stir zone was within 30-150 nm. This resulted in 50% increase in the fatigue strength of nanostructured specimen. Furthermore, the fracture surfaces were characterized using field emission scanning electron microscopy and scanning electron microscopy. As for the fatigue behavior of nanograin IF steel, the fracture surface was characterized by the formation of nanospacing striations and nanodimples. Besides, the nanograin structure pronounced the passivity and exhibited higher corrosion resistance.

Key words: Nanograin, Interstitial-free (IF) steel, Fatigue, Friction stir processing (FSP), Corrosion