Abstract
In composite-type vibration-damping steel sheets, surface pre-treatment for the skin steel sheets has been examined and discussed for cold-rolled steel sheets, chromate-treated steel sheets, and electro-galvanized steel sheets (EG). The evaluation was based on the bond interface durability produced during salt spray testing up to 1000 h. Chromate treatment was confirmed to be the best surface pre-treatment for skin sheets, because it improves the primary (pre salt-spray-test) adhesion strength and prevents decreased secondary (post salt-spray) adhesion strength. EG has no ability to suppress the decrement of secondary adhesion strength, because Zn dissolves in water and edge-creep goes on. The failure mode in T-peel test changes from cohesive to inteface failure with decreasing secondary adhesion strength and with the occurrence of edge-creep.
