Suppression of hydrogen-induced damage in friction stir welded low carbon steel joints

摘要

Hydrogen-induced damage including blister and cracking in friction stir welded low carbon steel were evaluated by the cathodic hydrogen charging method. After hydrogen charging for 2 h, irreversible dome-shaped blisters and internal cracking began to appear on the surface of the base metal. However, after hydrogen charging for 16 h, cracking formed along the thermo-mechanically affected zone boundary, while the blisters or cracking were hardly observed in the stir zone. In addition, the stir zone showed a plasticity reduction from 38% to 28%, much less than that of the base metal reduced from 48% to 2%. (C) 2015 Elsevier Ltd. All rights reserved.