2004 Volume 22 Issue 4 Pages 551-556
Hot dip metal plating is considered to be effective for increasing corrosion resistance in steel structures. The planting makes possible to reduce the residual stress in the welded portion due to annealing effect, and stress concentration at the weld toe is reduced by the plating if a part of stress is transmitted in the aluminum layer. Therefore, it is considered that fatigue strength can be improved by hot dip aluminum coating. These facts mean that the hot dip aluminum coating is one of useful countermeasure against the fatigue and corrosion, which are regarded as weaknesses of steel structures. However, it has not been clear how the planting influences the fatigue strength of a welded joint. This study aims at clarifying fatigue strength of welded joints coated with aluminum. For this purpose, out-of-plane gusset welded joints specimens were made of SM400 and were plated on two conditions of hot dip aluminum coating, then fatigue tests were carried out on these specimens. Furthermore, microstructures on the plating layer and fatigue crack origin were closely observed.
