Cathodic Current of Steel Structures with Seawater Resistant Stainless Steel and Estimation of Weight Loss of Sacrificial Anode
Takao KITAGAWA and Makoto TODOROBARU, Akihiro TAMADA, Hiroyuki WAKANA and Shukuji ASAKURA
Abstract:An exposure test was conducted on test specimens simulating marine structures to which cathodic protection was applied. Test specimens of seawater resistant stainless steel plates and those of carbon steel plates exposed to the tidal zone environment were analyzed. We measured the density of cathodic current flowing into the test specimens, corrosion rate of the specimens and weight loss of sacrificial anode. The cathodic current density was influenced by the reduction of rust and calcareous deposits. Weight loss of the anode calculated using cathodic current was found to be approximately the same as that obtained from the experiment. Weight loss of the anode for seawater resistant stainless steel as a test specimen was approximately 60% for those of carbon steel plates. Furthermore, we investigated the design method for cathodic protection taking into account the current flowing into the plate placed at the tidal zone. Key Words:Marine steel structure, Seawater resistant stainless steel, Carbon steel, Design standard, Cathodic protection