HVOF sprayed (JP5000) coating for a hydro-power application.

Choice between Stellite 6 or Ultimet. Both seem to be very similar. Ultimet is newer and some people have been pointing it as superior versus Stellite 6.

Any thoughts on which might be better or experiences?

Thanks
Jim

Hi Jim

to the Surface Engineering Forum.

Stellite 6 and WC/CoCr HVOF coatings seem to be in favour for thermal spray coatings for hydro-power applications. Interesting though, I not seen any direct comparisons between these two specific coatings. The nature of erosion, cavitation and corrosion in these applications is very complex. While one coating may perform better than another in one specific application, this may be reversed for another application, say like when there is more sand or silt in the water, making erosion a more dominant factor. As yet I only heard of Ultimet material being used as weld overlay, but it does sound like a possible alternative to stellite 6 as an HVOF coating. The only way really to find out is to test them side by side in the same conditions as your application.

These links should be of interest on this subject:

Study of Combined Effect of Sand Erosion and Cavitation
in Hydraulic Turbines

Selecting the Best Coating Systems for Hydropower Plants

Optimized maintenance solutions for hydropower plants

Cavitation- and Erosion-Resistant Thermal Spray Coatings follow the next page link to see many pages. Conclusions are on: http://www.cecer.army.mil/techreports/bo...jef-13.htm

Thank you for the info and links.

Intel55 Wrote:Thank you for the info and links.

Hi,
We have worked on considerable reasearch on finding solution of hydroturbine wear in India (also coating on OEM) for decades.Gordon is absolutely right in saying that coating material/process of application depend entirely on wear environment.If you go by consumable /system manufacturers' brochures containing universal solution, you may land up in unending problems.
ram chattopadhyay