Which ASTM galling tests are you looking for ? I do not have very successful experience with ASTM Galling test. You may want to consider developing your own test for your own application.
Luxeal
Check also this article from Velan. A vision of the FE challenge from a valve manufacturer point of view.
http://www.velan.com/ignitionweb/data/library/228/files/Zeroemissions.pdf
Based on experience, proper maintenance is key to maintain low emission
Luxeal
I learned the hard way that HVOF-Cr3C2 can embritteled when exposed to 1,400F. Embrittlement leads to hardness increase, crack propagation and coating failure.
Customer suggests to switch from HVOF-Cr3C2 to NiCrB Spray-and-Fuse (C88). Does somebody experienced SF C88 at 1,400F? Knowing...
I have tested large multi-turn Sambo gear boxes on globe and gate valves. Typically, Sambo mechanical advantages are attractive (better than most manufacturers) and their design is very robust.
Luxeal