Alstom Thermal Services AmStar 888 Kraftvärme Conference, Sweden Jiri Kubricht October 17 & 18, 2013
So, what is AmStar 888 material and how can it be used? AmStar 888 is a patented nickel-chrome alloy that is applied by High Velocity spraying. a cladding with extreme corrosion protection and high erosion resistance a cladding that can be sprayed over new or existing wasted, corroded, contaminated or eroded material. Nominal Composition (excluding B & C): Chrome 43% Nickel 53% Other (Al, Ti, Nb, Ta, Si) Balance
AmStar 888 - Product developed for Field application AmStar 888 is designed to be sprayed on site over in-service components that may contain corrosion related defects and contamination. Can be applied over existing water walls, on old corroded or eroded boiler tubes. Equipment is robust, lightweight, low heat output easy to transport to any site Europe. Equipment is compact, easily maneuverable on wheels. Safe operation (no gases). Propellant is supersonic air jet, Heat source is electric arc.
AmStar 888 applications AmStar 888 Cladding is applicable in corrosion environment with presence of flue gasses containing Sulfur, Chlorine, Vanadium, etc. or high erosive environment. Typical boilers where the cladding is applied on boiler water-walls and/or back-pass: Pulverized Coal-fired boilers Oil-fired boilers (crude-oil & HFO) Circulated Fluidized Bed boilers (CFB) Biomass Boilers Waste to Energy boilers Black Liquor Recovery boilers (BLRB) Co-fired boilers Petrochemical tanks/containers Digesters in Pulp & Paper industry AmStar 888 cladding can be used to repair thinned/damaged materials to protect materials and enable significant life-extension
AmStar 888 Corrosion resistance at high temperature AmStar 888 s designed to prevent corrosion wastage of carbon steel components (PC boiler water-walls). AmStar 888 has extreme Corrosion resistance at high temperature (18x better than Inconel 625 @ 500 C, or 180x better then carbon steel). AmStar888 layer is not thinning in corrosion environment like flue gasses containing Sulfur, Chlorine, Vanadium, etc. Coating remains adherent with a simple ability for restoration should it be defective by some unforeseen mechanism (e.g. destructive testing)
AmStar 888 Erosion resistance AmStar 888 Cladding is designed to prevent Erosion wastage of carbon steel components in high temperatures (typically CFB boiler water-walls). AmStar 888 layer is 5x more Erosion resistant then carbon steel at 300 C Hardness 68 HRC (hard steel e.g. chisels); quality knife blades: 55 60 HRC. More erosive environment is challenged by bigger AmStar 888 layer thickness (AmStar 888 layer thickness is scalable ) Eroded AmStar layer can be recovered (Amstar 888 layer is fully repairable)
AmStar 888 - Scalable thickness AmStar 888 layer thickness is perfectly scalable from 0 to 6 mm. AmStar 888 Cladding with high thickness does not crack or delaminate. Thickness for boiler Corrosion is typically 0.15 and 0.5 mm. Typical thickness for boiler Erosion is variable from 0.3 to 1.00 mm, depending on local aggressiveness.
AmStar 888 - Measurable Thickness The layer thickness is perfectly measureable as long as under-laying material is magnetic. (AmStar 888 doesn t contain any Fe). Thickness measurement is necessary for spray quality control. AmStar 888 can be sprayed very thick (>6 mm), usual thickness is between 0.15 and 1 mm
AmStar 888 - Reparability of AmStar layer AmStar 888 layer is fully repairable. Can be inspected and refurbished indefinitely => key factor for erosion applications. Following surface preparation, before spraying Following surface preparation, after spraying
AmStar 888 - Stress-free, no spalling/peeling AmStar Cladding manufacturing technology doesn t generate any internal stress, neither in layer, nor in substrate doesn t spall/peel off doesn t delaminate
New results show that the 888 alloy proves to be sustainable even in the most exposed environments a Waste-to-Energy boiler. AEB in Amsterdam, the Netherlands, built a new WtE boiler in 2006. Already in 2008, the boiler tubes showed severe thickness thinning despite of the use of weld-overlay AEB decided to invite six companies to address the challenge: apply new material on top of weld-overlay three companies to perform weld-overlay three companies to perform thermal metal spray, one of these companies was AmStar/Alstom This summer, 2013, samples of the thermal-sprayed tubes were removed and the result for the 888 alloy was very good and proves that we are closing up to the new technology paradigm of thermal metal spray. Presentation title - 01/01/2007 - P 11
AEB Amsterdam Case Study Page 1 5-year sample result Year 2008 - AmStar 888 new sample application New sample application of AmStar 888 over weld-overlay at the AEB facility, showing the completed cladding (light grey) sprayed over deteriorated weld-overlay on water wall tubes. The cladding was applied in December 2008.
AEB Amsterdam Case Study Page 2 5-year sample result Year 2009 - Sample application after 1 year service AmStar 888c cladding inspected the following year (2009), showing good adhesion & integrity
AEB Amsterdam Case Study Page 3 5-year sample result Year 2009 - Competitor s application after 1 year service To demonstrate that coating failure is visually apparent, the above picture is a competitor s spray application, in the same test and boiler, that show s significant deterioration at the first year inspection (multiple vendors were selected for the test.) This section was removed from further testing, with only the AmStar 888 spray cladding and Inconel 686 weld overlay being considered successful and able to continue the testing program.
AEB Amsterdam Case Study Page 4 5-year sample result Year 2013 - Sample application after 5 year service AmStar 888 cladding after 5 years in service.
AEB Amsterdam Case Study Page 5 5-year sample result AmStar 888 cladding after 5 years service, fully adherent and metallurgically suitable for ongoing boiler operation Exposed weld overlay following abrasive blasting removal of the protective AmStar 888 cladding Year 2013 - Sample application after 5 year service, cladding stripped in labs Since the coating was fully adherent, and its thickness could not be measured due to the presence of underlying 625 weld overlay, a section of the cladding needed to be removed by abrasive blasting to establish its presence and continued effectiveness in protecting the substrate, as shown above.
What is AmStar 888 Cladding?
AmStar 888 - glance of Field & Workshop projects
AmStar 888 Workshop application (Houston, TX & Brno, Czech rep.
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