×
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

Super Duplex micrograph

Super Duplex micrograph

Super Duplex micrograph

(OP)
Can any one confirm what should be accetable proportion of Ferrite and Austenite phase in ASTM A 890 Grade 5A

RE: Super Duplex micrograph

If its new material, I think it should be 50%.

For welding it depends on the requirements of the application standard that you are using.  Normally for British codes the range is 30% to 70% ferrite.

Regards
John   www.gowelding.com

RE: Super Duplex micrograph

I don't know of any industry standards in this area, but our customers often specify 40-60% (Not FN)  If you are interested in better impact properties, you may want the ferrite to be as low as 30%.  I think though, if the material meets the mechanical properties, and the corrosion requirements, should it really matter that much what the phase balance is?

RE: Super Duplex micrograph

I agree with GRoberts - we would normally get asked for 40-60% or 35-55% as the ferrite range in duplex stainless. We find that 45-50% gives good impact properties, provided that chemistry and heat treatment are OK.

I also agree that ferrite percent probably doesn't matter if everything else is OK, but if that's what the customer wants, then that's what he's going to get. I guess that these requirements have grown out of a long period of alloy development and experience in service. There may also be an element of borrowing copies of other people's specifications and re-hashng them as your own until it become industry standard (we have seen this)

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