Cryogenic treatment for 316 , 304 valve parts.

[bao2ye]

Hello, valve experts,

Do we need to cryogenic treat valve parts, made of SS316 and SS304 in casting and forging, which will serve at -196 Celsius, before machining?

I am worry about phase transition at low temperature: austenite transforms to martensite phase and cause shape changing.

Thank you very much

Bao

 

[gustorf]

I would say - No.

 

[TOVmania]

For large sizes, you may want to perform Sub Zero Heat treament for dimensional stability under such environment. Only retained austenite changes to martensite, not all of them.