Stellite on high temperature valve spindles and dilution
Stellite on high temperature valve spindles and dilution
(OP)
Have a query regarding on above subject, mainly as it applies to the power gen industry (turbine valves).
My understanding is that it is common practice to apply stellite 6 on alloy steel spindles to prevent oxide build-up and associated jamming.
How critical is dilution given the application?
Reading some literature from Deloro, dilution of iron in the stellite reduces hardness and wear resistance, although I would've thought wear resistance isn't a big priority here.
Dilution with iron also has the unusual side-effect of increasing toughness as the brittle carbide phase content is effectively decreased.
The key property I would've thought would be the oxidation resistance - I imagine this is mainly related to the Cr content, so I'm not sure whether iron dilution (say up to 20%) would affect this much.
Is anyone able to comment?
My understanding is that it is common practice to apply stellite 6 on alloy steel spindles to prevent oxide build-up and associated jamming.
How critical is dilution given the application?
Reading some literature from Deloro, dilution of iron in the stellite reduces hardness and wear resistance, although I would've thought wear resistance isn't a big priority here.
Dilution with iron also has the unusual side-effect of increasing toughness as the brittle carbide phase content is effectively decreased.
The key property I would've thought would be the oxidation resistance - I imagine this is mainly related to the Cr content, so I'm not sure whether iron dilution (say up to 20%) would affect this much.
Is anyone able to comment?





RE: Stellite on high temperature valve spindles and dilution
We have Stellite 6 on most if not all of our turbine stop and gov valve seats. No issues with dilution provided you have enough of a weld deposit. We usually have 1/8" with absolutely no issues. If youlap the Stellite over the years this can still leave an effective weld deposit. The problem is machining versus lapping.