Surface modification of D36 steel by ultrasonic impact with electropulsing

ABSTRACT

The present work investigated the effect of ultrasonic impact treatment (UIT) assisted with electropulsing (EP) on the microstructure of D36 low-carbon steel. Optical microscope and scanning electron microscope were employed to reveal the microstructural evolution of the specimen subjected to the treatment. In comparison with UIT solely, a higher hardness on the superficial layer was obtained by EP-UIT and the fracture on treated surface was avoided effectively which meant a better plasticity. The electron back scatter diffraction analysis indicated a high density of low-angle boundary network owing to the large strain introduced. The distinguishing features of EP-UIT were ascribed to the athermal effect of drifting electrons which facilitate the mobilising of dislocations in the deformation.

This paper is part of a themed issue on Materials in External Fields.

KEYWORDS:

• Ultrasonic impact treatment
• electropulsing
• low carbon steel
• hardness
• microstructure

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCiD

Tao Liu http://orcid.org/0000-0002-6872-3796

Additional information

Funding

This work has been funded by projects from ShenZhen Government (Grant No. HYCYGJ20140512010015 and No. CXZZ20140702113545562).