- Design and assemble a test facility capable of simulating metal dusting and similar high temperature corrosion mechanisms
- Validate the test facility by means of a case study of testing under a high temperature carburising environment and an environment projected to cause metal dusting
- Identify and test substrate alloys and coated alloys expected to have significant resistance to high temperature corrosion
Over the past few years, TWI has developed facilities for high temperature corrosion testing in response to increasing Industrial Member need for data pertaining to material performance in high temperature service. These environments include but are not limited to oxidizing, carburizing, metal dusting, biomass burning, molten salts and combustion environments. Given the variety of service environments, any practical test facility must be flexible with regard to temperature, thermal cycling, gases, flow rates and pressure.
Metal dusting is the accelerated degradation of metals in a carburizing/oxidizing environment (where the activity of carbon (ac) is >1) often experienced in high temperature combustion and chemical process plants. Significant effort has gone into the development of metal-dusting resistant alloys (typically based on nickel) but these materials have limited weldability. Comparatively less work has been done on the performance of coated alloys and one objective of this project is to obtain information on such alloy and coating performance in high temperature service.
The second objective is the study of very high temperature corrosion in a reducing/carburizing environment (>1000°C) towards material selection, investigating the effect of alloy composition, surface finish, coating and the presence of metal oxides at the substrate surface.
It is proposed that this be achieved by commissioning an upgraded an upgraded test facility capable of simulating metal dusting and similar high temperature corrosion mechanisms, validating the test facility and identifying and testing (coated) substrate alloys expected to have significant resistance to this service.
This project aligns with key drivers identified by TWI in the Power Industry Sector related to:
- Plant safety and availability improvement
This project supports two MCS/ SUR technology strands:
- High temperature coatings (biomass etc.)
- Corrosion testing of coatings
Relevant Industry Sectors
Technical and Economic Benefits
The new facilities and expertise will be available to all TWI members for high temperature corrosion testing in a variety of ambient pressure gaseous environments (at temperatures up to 1120°C), including CO, CO2, H2O, H2, HCl, CH4 and various mixtures thereof. Selection of appropriate service conditions for accelerated testing allows more rapid material selection and corrosion trials, saving both time and cost in material validation.
The data from this project may allow better material selection for challenging service leading to increased component lifetime with associated cost savings. This includes potential selection of coatings and other protective methods to mitigate damage and increase service life. The understanding of related engineering issues (e.g. reduction of oxides in contact with the substrate surface, or erosion) affecting high temperature corrosion in these environments provides additional information on methods of mitigating this damage without changing the underlying materials of construction.