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Geo-coat gets preliminary results from exposure tests!

Thu, 20 August, 2020

The green stimulus package offers promises of economic recovery, and a clean energy future out of the COVID-19 pandemic. Despite investment opportunities energy technologies at an earlier stage of development and deployment, such as geothermal, may struggle as investors take a more conservative position on risk in the aftershock of the pandemic. Techno-economic challenges including high operational and maintenance costs of geothermal plants due to the inherent aggressive environments, makes geothermal vulnerable calling for sustainable research and innovations to mitigate the impact of these additional factors.

Geo-Coat promises novel and high-performance materials and coatings for geothermal applications. As the project enters the final phase of its research and development, the Geo-Coat researchers are excited to evaluate the results post completion of the exposure and field tests of the flat coupons in the real geothermal environments. These have been performed, in parallel, at the University of Iceland (flow-through corrosion in simulated geothermal environment), TWI Ltd (static and SCC corrosion in simulated geothermal environment), Innovation Centre Iceland/ON Power (field tests) and The Weir Group (lab-based erosion-corrosion).

The resistance of the coatings and MMCs to the harsh testing environments is currently being analysed by means of Optical microscopy, SEM-EDX and other in-depth characterisation techniques. The aim is to assess the ability of the coatings to resist erosive load from the geothermal fluid flow, permeation of geothermal fluid and formation of localised forms of corrosion, which could be detrimental to the lifetime of the coated components. In order to evaluate the Geo-Coat technology for service applications, welded coupons have also been tested. In this case, carbon steel substrates laser cladded with CoCrFeMoxNi High Entropy Alloy were welded by Tungsten Inert Gas (TIG) by using Inconel Alloy 625 wire. In this case, the post-exposure analysis is focused on the possible galvanic effects at the coating/weld interaction zone to establish the occurrence of preferential corrosion.  

The stage is set! Now we wait for the results.

Inconel Alloy 625/SiC MMC coupon after static exposure in simulated geothermal environment at TWI Ltd
Inconel Alloy 625/SiC MMC coupon after static exposure in simulated geothermal environment at TWI Ltd