304 Stainlees Steel or 321 Stainlees Steel
304 Stainlees Steel or 321 Stainlees Steel
(OP)
I have a heater which is in hydrogen service. The maximum design temperature is 520 DegC. Can I use 304 SS at this temperature? Or do I need to select stablized 321 SS for this service?





RE: 304 Stainlees Steel or 321 Stainlees Steel
RE: 304 Stainlees Steel or 321 Stainlees Steel
In my opinion you've to consider the max operating temp that usually is appreciably lower.
If your process can reach the 510°C for short time then the 304 can be used.
S
Corrosion Prevention & Corrosion Control
RE: 304 Stainlees Steel or 321 Stainlees Steel
Do I need to specify that 321SS should be stabilized? How about the solution treated 321SS?
RE: 304 Stainlees Steel or 321 Stainlees Steel
I would not use 304 ss because you are right at the TTS C curve lower limit of sensitization for this grade of austenitic stainless steel, and the TP321 has higher allowable stress in comparison to 304 ss at this service temperature.
Yes, the TP 321 SS should be stabilized before use in service to obtain maximum corrosion protection.
RE: 304 Stainlees Steel or 321 Stainlees Steel
Do the right thing and use 321 or 347.
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