×
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

SA156-70

SA156-70

SA156-70

(OP)
Currently conducting (Automatic GMAW+P) weld metal build up repairs on the inside of a heat exchanger. Material is SA516-70 (¾" thick). Surface was sand blasted & a hydrogen bake out @ 500⁰F for two hours was completed before welding. Final weld repair location was inspected using liquid penetrant (PT) no relevant indications. First layer was welded surface was ground to smooth surface. PT inspected with no relevant indications noted. Second layer was welded & same surface prep & inspection (PT) as the first layer with no relevant indications. When Tube bundle was installed it was noted there was not enough clearance we were requested to remove some additional weld metal @ this time there were porosity indications noted after more grinding there is now significant porosity. During the welding there were no indications of porosity & the machine also has a low gas sensor. This vessel has been in service for thirty years. Service Shell Side-Hydro Carbons (Naphtha), Operating Shell side 200psig @ 650⁰F. I am thinking there may be an issue with the base metal. Graphitization possibly.

RE: SA156-70

Temperature is too low for graphitization. Improper pulsing (pulse rate) can readily lead to subsurface porosity in pulsed transfer GMAW process.

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