Research paper

Journal of Materials Research and Technology

Effect of multifunction cavitation-treated carbon steel surface on fracture toughness

Masataka Ijiri, Takayuki Ogi, Kyosuke Murakami, Horiguchi Shoma, Toshihiko Yoshimura

19

3546

3553

Elsevier

Improving the strength of an object by surface treatment inevitably trades off strength and ductility, and also reduces toughness. In this study, carbon steel was treated by a surface modification technique, referred to as multifunction cavitation technology (MFC), and the improvement of strength and toughness was investigated. Peening marks, pits, and rust were observed in the MFC-treated carbon steel as the processing time increased. In addition, the surface roughness of MFC-treated carbon steel increased and the surface potential decreased. The residual stress and hardness of the MFC-treated surface increased the processing time to 5 min, but gradually decreased after that. A Charpy impact test was performed to evaluate toughness. The transition region between the untreated material and the MFC-treated material after the Charpy impact test was 280 to 380 K. The MFC-treated material had a lower transition temperature and higher absorption energy than the untreated material, so it was effective in improving toughness.