Effect of Sulphite Sediment on Hydrogen Embrittlement Susceptivity of Hot-dip Galvanized Steel Exposed to Simulated Marine Atmosphere

摘要

Hydrogen permeation and embrittlement behavior of hot-dip galvanized steels with different sulphite sediment on surface exposed to stimulant marine atmospheric environment was investigated by hydrogen permeation current measurement using modified Devanathan-Stachurski cell, slow strain rate tensile test and scanning electron microscopy technique. The results indicated that hydrogen permeation curves were increasing along with the sediment rising gradually. On the other hand, it was found that hydrogen absorption was accelerated by the cathodic protection of scratched steel surface afforded by zinc coating. Hydrogen absorption and permeation reduced the percentage elongation after fracture of galvanized steel specimens; meanwhile, the fracture characteristics of samples fringe occurred some lacerated phenomena, i.e., galvanized steels show a higher susceptivity of hydrogen embrittlement when exposed to marine atmospheric environment with sulphite.