Valve seizure in automotive application (stellite galling issue)
Valve seizure in automotive application (stellite galling issue)
(OP)
Hi,
I am experiencing a problem with a valve seizure on a high temperature (600ºC) automotive application. The shaft is stellite 6 which is being used in a 420V vanadium stainless steel bushing. The valves are seizing, and examination of the surfaces seems to show that this is due to galling.
Has any one seen any similar issues or these materials, or has anyone any ideas on a more suitable material choice?
Thanks
Andrew
I am experiencing a problem with a valve seizure on a high temperature (600ºC) automotive application. The shaft is stellite 6 which is being used in a 420V vanadium stainless steel bushing. The valves are seizing, and examination of the surfaces seems to show that this is due to galling.
Has any one seen any similar issues or these materials, or has anyone any ideas on a more suitable material choice?
Thanks
Andrew





RE: Valve seizure in automotive application (stellite galling issue)
Have you looked at your coefficients of thermal expansion? Possibly your clearances are closing up as the assembly heats up.
RE: Valve seizure in automotive application (stellite galling issue)
Also, consider changing the bushing to a Nitronic 60 alloy. If you can get ahold of a copy of Electralloy bulletin E-60, "Nitronic 60 Stainless Steel", it has a wealth of information on galling resistance of various materials. Interestingly, N-60 has somewhat worse gall resistance than Stellite 6B at room temp., but much better resistance than 6B at high temperatures (1000 F). Unfortunately, the bulletin lists no data for type 420.
RE: Valve seizure in automotive application (stellite galling issue)