Healing of Fatigue Crack by High-Density Electropulsing in Austenitic Stainless Steel Treated with the Surface-Activated Pre-Coating

• Main Authors: Atsushi Hosoi, Yang Ju, Tomoya Kishi
• Format: Article
• Language: English
• Published: MDPI AG 2013-09-01
• Series: Materials
• Subjects: healing; crack; fatigue; electropulsing; propagation; coating
• Online Access: http://www.mdpi.com/1996-1944/6/9/4213

A technique to heal a fatigue crack in austenitic stainless steel SUS316 by applying a controlled, high-density pulsed current was developed. A surface-activated pre-coating (SAPC), which eliminates the oxide layer and coats a Ni film on the crack surface, was used to improve the adhesion between crack surfaces. Cracks were observed by scanning electron microscopy before and after the application of high-density electropulsing. To evaluate the healing effect of the SAPC during crack propagation, fatigue tests were conducted under a constant stress intensity factor. The fatigue crack treated with the SAPC was found to be effectively healed as a result of electropulsing, and also showed a slower rate of crack propagation.