×
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

Impact test and hardness test in the same PQR?

Impact test and hardness test in the same PQR?

Impact test and hardness test in the same PQR?

(OP)
Hi all.

Last week I came across a PQR which has both impact test and hardness test conducted in one PQR. I find that rather odd. Impact tests are for cold service, and thus you'd think that the weldment or material itself will need to be ductile (thus no point in taking hardness test). Hardness tests are for brittle material, in that you want to control the hardness post-weld.

Was the PQR "odd" (read: WRONG), or do I need to tweak my understanding a little bit?

Knowledge-enhancing replies, tips, pointers, sarcastic information, are much appreciated, :)

RE: Impact test and hardness test in the same PQR?

No, this is not odd at all. Hardness testing can be performed as part of the PQR to verify adequacy of PWHT, if applicable, OR if a temper bead procedure qualification was performed OR as part of an engineering specification to ensure a maximum hardness is met for corrosive service.

RE: Impact test and hardness test in the same PQR?

Hardness tests for procedure qualification are often specified in Engineering and Owners' specifications, especially in the petrochemical industry primarily, to (hopefully) ensure freedom from in-service stress corrosion cracking.

RE: Impact test and hardness test in the same PQR?

No conflict whatsoever.  

Your first misconception is confusing 'ductility' with 'low-temperature toughness'.  They are related but not the same.  

The second is thinking 'Hardness tests are for brittle material'.  Most often with ferritic steels hardness tests are used to measure the weld and heat-affected zone hardness.  There are various reasons to limit hardness, although it is a rather crude indicator of some other properties.   

RE: Impact test and hardness test in the same PQR?

Not at all uncommon in the pressure vessel world.  As stated, hardness tests verify effectiveness of PWHT when required, and impact testing is usually a requirement of ASME to verify the ductility of the material at it's minimum allowed pressurizing temperature.

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