×
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

420ss Hydrogen embrittlement

420ss Hydrogen embrittlement

420ss Hydrogen embrittlement

(OP)
I make a small stamped sheetmetal component out of 420ss annealed. Its .030 thick and has several small holes pierced thru in the annealed state. These parts then get heat-treated to 48-52Rc with a deep freeze and double temper process. After heat treat the parts are formed to a gentle S curve like ribbon candy (no hard bends). Then we Stress Relieve them at 700 deg F for 1 hr.
My qustion is, Does the stress relieve process itself reduce or aggrivate the potential for Hydrogen Embrittlement?

thanks,
Tom

Tom Malinski
http://www.okayind.com/
Dell Prec 670, Xeon 3.8,2GB Ram, Nvidia Quadra FX 3450/4000 SDI
SWorks Pro & PDMWorks 2007 SP3.0

RE: 420ss Hydrogen embrittlement

Heating Type 420 stainless steel to 700 F (370 C) means that you are essentially tempering it a third time, because this is the maximum tempering temperature used to obtain 48-52 HRC.  There will not be much stress relief at that temperature, so I don't think it will do much to either reduce or increase the chance for delayed fracture.

RE: 420ss Hydrogen embrittlement

It will reduce hydrogen, since diffusion is so fast at 700.  There is still the risk that the material contained hydrogen earlier in the process and you developed microcracking during earlier operations.

= = = = = = = = = = = = = = = = = = = =
Plymouth Tube

RE: 420ss Hydrogen embrittlement

If you have any concerns related to delayed cracking from hydrogen perform a wet fluorescent MT. If the parts have no reportable indications, they should be good to use.

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