×
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

Heat treated 431 or 19-9DL Steel

Heat treated 431 or 19-9DL Steel

Heat treated 431 or 19-9DL Steel

(OP)
Why are these two steels prohibited by most Military M&P Specs?  For example: MIL-STD-1587C (page 10)  I'm most interested in stainless alloy 431.  What would warrant a complete prohibition and if it were to be used what steps should be taken? (NDI...???)

RE: Heat treated 431 or 19-9DL Steel

(OP)
It looks like the low strength heat treatment can be found in NASM3-20 bolts.  Anyone know about 431 treated in the 200ksi range.  Issues??

RE: Heat treated 431 or 19-9DL Steel

At this strength level, there is a significant increase in susceptibility to stress corrosion cracking and hydrogen embrittlement in certain environments.

RE: Heat treated 431 or 19-9DL Steel

(OP)
metengr,

Why a ban on all heat treated 431?  

RE: Heat treated 431 or 19-9DL Steel

mighoser;
I'm not an aerospace standards expert, only a boiler and pressure vessel/Power Generation metallurgist. Just for kicks I did review the Carpenter web site (see at the end of this post), because they supply Type 431 stainless steel. Low and behold, they do reference this material for use in the following military specifications;

MIL-S-18732
AMS-5628


http://www.cartech.com/
You can register for free and locate Type 431 stainless steel under High Strength, Conventionally-Hardened Grades. An excellent technical database for future reference.

RE: Heat treated 431 or 19-9DL Steel

(OP)
Metengr,

Mil-s-18732 is inactive for new design.  We do spec stainless 431 to ams-5628 but were required to get a waiver to use it.  I wonder if this prohibition is the sum of several bad experiences with the alloy in the heat treated condition.

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