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

Stress Relief Time and Temp for Aluminum

Stress Relief Time and Temp for Aluminum

Stress Relief Time and Temp for Aluminum

I'm looking into my company's long-standing Stress Relieving Process, and I don't understand what I'm seeing. In the absence of a specific call out (i.e. 'Stress Relieve' vs. 'Stress Relieve iaw SPEC at 000F for Xhrs'), how do we know what temperatures to use?

We have a posted time and temperature chart for various aluminum alloys, but it doesn't reference any specifications. It lists the time/temp for 6061 as 350F for 4h. The 'normal' Aluminum Heat Treating specification, AMS 2770 references Stress Relieving as a 'Partial Anneal' and suggests temperatures in the range of 630-660F for 6061. I've found several other forum posts and customer specifications (including top AS&D companies) that agree with our lower temperature, some of which even acknowledge that the higher temperatures given in AMS 2770 will negatively affect the strength of the material.

I asked our guys where our chart numbers came from, the answer was 'the local heat treating expert told us to stay below the lower limit for aging in AMS 2770'. I have no reason to double the process - it produces results and lines up with our customers' instructions, but this answer doesn't really fly from a quality perspective.

What's going on? It seems to be generally accepted that you'd stress relieve something like 6061 at 350F, but there is no specification referenced by any of the sources I found permitting that. Where are these temperatures coming from? Is this really a 'Stress Relief', or is it something else? Can anyone shed some light on this?

RE: Stress Relief Time and Temp for Aluminum

350F is a typical ageing temperature for 6061-Txxx. If you stress relieve on top of this, you will reduce the mechanical properties of the product. What are you trying to accomplish? What is the product form?

RE: Stress Relief Time and Temp for Aluminum

Sounds like an age hardening cycle. Four hours is not necessary. For steels ASME generally calls for one hour per inch thickness.

RE: Stress Relief Time and Temp for Aluminum

I agree, it sounds like someone carelessly called age hardening ’stress relief’.

I would start over from first principles:
Determine what alloy you have and research an appropriate heat treatment for the properties you want. ASM handbook would have the info, but you can also google.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

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