×
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

A-182 F-53 super duplex STAINLESS
2

A-182 F-53 super duplex STAINLESS

A-182 F-53 super duplex STAINLESS

(OP)
An UT thickness inspection crew took thickness readings on a A-182 F-53 super duplex 8" reducer. At the time of inspection, the material wasn't known. The crew calibrated to S/S and achieved a reading of .138". I knew that wasn't correct. I had them calibrate to C/S due to the fact of the material being magnetic and achieved a reading of .375". At that time they achieved proper readings on same. Why is the material called S/S yet has a carbon make up? Is it because of it's corrosion inhibitor factor?



 


API-510 cert # 32890

RE: A-182 F-53 super duplex STAINLESS

retthib;
Your assumption is not correct. The F-53 is a super duplex stainless steel that contains ferrite/austenite. You need to have a calibration standard for this material. You just got lucky because the ferrite in this material responded like ferrite in carbon steel. You need to have a calibration gage made out of F-53 duplex ss.  

RE: A-182 F-53 super duplex STAINLESS

(OP)
Yes we are working on that, just was wondering why with a material name S/S we achieved a more accurate reading calibrated to C/S. I figured it was due to the carbon content, but thanks for clearing that up.


API-510 cert # 32890

RE: A-182 F-53 super duplex STAINLESS

retthib,

The "duplex" in duplex stainless means that it has the best characteristics of both the carbon and "stainless" worlds.

From what you have said, I believe that you consider the word "stainless" to mean an austenitic (non-magnetic)material.....Not true

The current meaning of "stainless" as I understand it, simply means that it has a certain minimum percentage of chrome and can be of austenitic, ferritic or martensitic structure.

http://www.alleghenyludlum.com/pages/products/xq/asp/G.2/qx/ProductLine.html

http://www.matweb.com/search/datasheettext.aspx?matguid=59b6c05b82cb41cfb102bd8dc6cb3a52

http://www.thefabricator.com/MetalsMaterials/MetalsMaterials_Article.cfm?ID=1550

-MJC

   

RE: A-182 F-53 super duplex STAINLESS

retthib,

How do you know that the 0,375" reading is accurate when, in response to metengr's sound (no pun intended)advice to obtain a piece of the same material of known thickness from which to calibrate, you are still "working on it"? Or perhaps there is a typo somewhere in your description?

I am not saying that the figure of 0,375" is neecesarily wrong (or the 0,138" right), but something is definitely amiss when by  recalibrating for carbon from stainless (nominally a maximum velocity change of about 20 - 25% with mild steel at 5960 m/s and 410 stainless at 7390 m/s)your UT crew gave you a reading variation of 0,138" to 0,375", i.e. some 270%!

I would be more worried about what that UT crew is up to than anything else!

Nigel Armstrong
Karachaganak Petroleum
Kazakhstan

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