Corrosion Behavior of Intumescent Coated Steel In Seawater Environment

Intumescent coating is a mineral based or organic resin based product functioning as fire retardant coating where it can be applied to metallic materials, polymers, textiles, wood as well as structural steel in buildings, storage tank in order to protect them from weakening when encounter elevated temperature in a fire. Most of the offshore and marine structure are heavily exposed to the marine environment mainly seawater which is one of the corrosion medium. Coating protect steels through barrier layer action of the coating, secondary barrier action of corrosion product layer. The presence of the mechanical damage allows the access of corrodents to the substrate, eventually resulting in destruction of the coating by the growth of corrosion products. Researcher will develop an intumescent coating formulation which consist of three agents mainly Acid Source (AAP, Polyphosphate), Carbon source (EG, Expandable Graphite) and blowing agent (MEL, Melamin) followed by epoxy, Boric Acid, Polyamide Hardner and etc to the steel and exposed it to the seawater environment. Various percentage of coated area will be applied to the substrate as manipulated variable. Corrosion effect will be evaluated using visual inspection and microscopic view. The substrates later will be testing on fire retardant performance by bunsen burner test. The char expansion as well as heat shielding will be thoroughly observed and result will be obtained and further studied.