Contact US

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!

*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

Temper Embrittlement of LAS pipes ?

Temper Embrittlement of LAS pipes ?

Temper Embrittlement of LAS pipes ?

API 934 A,B,C and D clarifies the impact and preventive actions for Temper Embrittlement for thick Low alloy steel (1.25Cr0.5Mo,2.25Cr0.5Mo etc..)vessels but i have never found anything for LAS pipes?

Does LAS pipes are not susceptible to Temper Embrittlement?

I believe "TE" is related to basic material of construction, temperature range and time. But no where any such damage mechanism is covered in any code for pipes.

Please share your views or any such issues you have come ac-crossed.

RE: Temper Embrittlement of LAS pipes ?

Low alloy steel pipe material can become thermally embrittled, similar to plate steels used in vessels. The only difference being thickness and metal temperature, where the pipe thickness can be much thinner in comparison to vessels, which does play a significant role in notch toughness behavior.

For pipe or even vessels operating at elevated temperature even thermally embrittled pipe or vessel material will most likely be in the upper shelf region and exhibit increased notch toughness. The concern is either pipe or vessel metal temperature near ambient where the embrittled material will be subjected to internal pressure. In this case, thick-walled vessels are at greater risk of brittle fracture rather than piping, when subjected to ambient temperature pressure.

RE: Temper Embrittlement of LAS pipes ?

what does "heavy wall" means ? can it be quantified in terms of thickness ?

RE: Temper Embrittlement of LAS pipes ?

If you mean thick walled vessels - greater than 3" thickness, typically.

RE: Temper Embrittlement of LAS pipes ?

Those low alloy steels that are typically subject to temper embrittlement are Cr-Mo, Mn-Mo, and Ni-Mn-Mo alloys. Mn-Mo and Ni-Mn-Mo steels have been used in place of C-Mo alloys in heavier wall construction due to their increased tensile properties but one must take into account their embrittlement potential when operating at temperature between 700 F and 850 F and after PWHT.

RE: Temper Embrittlement of LAS pipes ?

@ metengr (Materials)
Thanks for your valuable response. I do agree that heavy wall thick vessels of Low alloy steels are more susceptible to "TE" as detailed in API 934 A,B &C. But from where this min thickness criteria( as you mentioned 3" and higher) comes from?

RE: Temper Embrittlement of LAS pipes ?

I was about to ask for the meaning of "thick wall" but i took the expression "heavy wall" from the title of API 934 =)

somme users use 50mm as a limit, but i found no definition in API 934.

1.25Cr-0.5Mo should not be selected for wall thickness above 3" due to difficulties in reaching required toughness for plates


RE: Temper Embrittlement of LAS pipes ?

Heavy wall thickness is not defined in the ASME Codes. In the 1970s, most Owners and Engineers considered the need for enhancd construction and materials toughness requirements for 4" wall and greater. In the 1980s, most of the Petrochemical Owners and Engineers had lowered these added requirements for 3" thickness and over and some down to 2.5". The work of Puzak and Pullini (not sure of spelling) provided much of the basis for addded requirement for heavy wall construction.

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! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close