×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

304 Stainlees Steel or 321 Stainlees Steel

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

Use 321 stainless steel.

RE: 304 Stainlees Steel or 321 Stainlees Steel

at that temperature you've to select the stabilized 321 but as you said 510°c is the max design temperature.
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

(OP)
Maximum Operating is 440 DegC. Looks like 304 should not be used, right?

Do I need to specify that 321SS should be stabilized? How about the solution treated 321SS?


RE: 304 Stainlees Steel or 321 Stainlees Steel

kissjxp;
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

If you used 304 it would have to L and you would be stuck with low strength and the risk of sensitization at the upper temps.
Do the right thing and use 321 or 347.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources