Heat Treating 330 SS in vacuum

[coatingsguy]

When running 330 stainless steel at 2250F in a vacuum of 5 -5 torr or better, should I be concerned about pulling out alloying elements such as chrom?

 

[Goahead]

The temperature seems high. Annealing is given at 2050 to 2200 F. From a diagram of Vapor pressure vs. Temperature, equilibrium for Chrome at that temperature is about
2*10^-2 torr. Your concern is probably correct unless treatment is very short. Could you backfill with inert gas?

http://www.welding-advisers.com/

 

[EdStainless]

Why vac instead of hydrogen?
yes, enven in H you get a little Cr vapor, it recondenses on the surface. It is very superficial.

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[arunmrao]

Did you observe any Ni evaporation in 330 under vacuum. A few of my customers who have used 330 castings under vacuum have made this report.