I think you are planning to conduct tests under super critical water oxidation conditions. If yes then stainless steel may not be an appropriate material. You have to go for a Ni-Cr-Mo alloy such as C-276.

Pressure sealing is typically provided by a knife edge arrangement with nickel foil compressed in between the knife edge and the V-groove, or a metallic ring compressed between the grooves of lid and the autoclave body.

Any autoclave manufacturer should be able to help you with this, for example visit cortest.com, amarequip.com etc.

Dear Vivek,

I can suggest you to go for High steel-High Chromium material. This combined material withstand even for high temperatures. If possible Try to do Nickle plating also.

Krishnan Raja Thank you sir for the detailed and informative reply. I am working on Phase Change Materials (PCM) I am planning to do corrosion test of SS316L in presence of few molten metals ( which will act as PCM and melting temperature less then 600 deg C).

Thank you for suggesting Autoclave manufacturers. I will start communicating with them.

Venkata Ramana Mudinepalli Thank you sir for your reply. I will refer to High steel-High Chromium materials.

Vivek Tiwari:

If the vapor pressure of molten salt or molten metals at 600 C is low, then you do not have to worry about high pressure. A sealing compound called 'Copaltite' works fine as high temperature pressure sealant.

If you are dealing with molten metal or molten salt, sealing is required for preventing oxidation of the molten materials. Use ultra high purity argon as a cover gas. Presence of oxygen or moisture will accelerate the corrosion of 316 SS.

All the best with your high temperature work! Good field of research!!

Krishnan Raja Thank you sir for your reply. I am grateful to you for your help. It helped me a lot.

I am happy that RG forum is able to help you. Wising you the best!