Evaluation of Various IMM/IC Coating Systems in Terms of Corrosion Protection

In Oil & Gas facilities projects, coating system selection of bulk valves is challenging for EPC contractor to manage because their quantity is extensive and they are installed at each specific situation. IMM (Inert Multi Polymeric Matrix) / IC (Inorganic Copolymer) coatings, hereinafter referred to as IMM, which can be applied under various situations are anticipated to be applied for the bulk valves. Several types of IMM paints have been introduced to the market and corrosion protection performance were evaluated in this paper. Test panels of IMM coatings were prepared from five different manufacture’s brands, with variations in dry film thickness, hereinafter referred as DFT, (125µm/250µm) and with or without heat curing. Corrosion protection performance was tested by salt spray tests (720 hours, 1440 hours) and natural weathering tests (18 month), and evaluated by degree of rust, pull-off tests, and EIS (Electrochemical Impedance Spectroscopy) tests. The results of salt spray tests and natural weathering tests varied depending on each brand's product. The overall trend indicates that panels with a 250µm DFT and without heat curing panels demonstrates better corrosion protection performance rather than panels with a 125µm DFT and with heat curing. In the EIS test, some test panels showed a significant drop in impedance values at low frequency (0.1Hz) with heat curing, which may suggest a degradation in corrosion protection performance. In conclusion, it is recommended to use IMM coatings with a 250µm DFT and to be cautious when applying them at high temperature services.
Product Number: 51324-20414-SG
Author: Daigo Koshiba; Takumi Oshikawa
Publication Date: 2024