×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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

Cast 304??
2

Cast 304??

Cast 304??

(OP)
Congrats mcguire on starting this new forum.

I had an enquiry from a customer to make end flanges used in autombile exhaust system. This has a DIN number(Equivalent to AISI 304) which I do not remember now. This is for Europe market. Originally this is being made as a forging but now it is intended to convert it into a casting due to cost considerations. This is a small flange about 150 mm OD and ID 130 mm and 10-12 mmthick. The finished weight is 650 grams. Quantities are 15000 peces/month.

 My question is will the inspector accept a cast product. As I see the service conditions are not too severe and CF8 casting should well serve the purpose.

Your comments please

RE: Cast 304??

I can talk to some technical points, but I do not know the role of the inspector. If the customer specifies CF8,its specification would seem to me what he should be inspecting to.
The technical considerations for a hot-end exhaust flange are the susceptibility to corrosion, oxidation, and mechanical failure. The principal difference is that the cast CF8 will have a more inhomogeneous microstructure. The will be significant delta ferrite which will hasten the formation of sigma at high temperatures, possibly at operating temperature. The result would then be low ductility at ambient temperatures.
  It requires a thorough high temperature solution anneal and quench to dissolve and keep carbon in solution, so you won't have sensitization. Even with that you will retain about 10% delta ferrite and non-equilibrium inclusions. The casting behaves like a TIG weld in that it has lower pitting corrosion resistance. The amount equals about 10C on the critical pitting temperature,depending on sulfur level.
  These considerations probably don't diminish its functionality as a hot-end flange since high temperature strength and oxidation resistance should approximate those of 304.
  Thanks for coming to the forum. I have appreciated your many valuable responses in the other materials forums.

RE: Cast 304??

I do not know about the European designations, However, the UNS number for SA-182 is S30400 for type 304 SSt and for SA-479 the UNS is S30403 for type 304L SSt.

John

RE: Cast 304??

There are some exhaust flanges in service that are SS PM parts, so castings don't seem out of place at all.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm

RE: Cast 304??

(OP)
Edstainless
I had suggested P/M route for this application. Though this is not my area of work.

RE: Cast 304??

PM is a great suggestion:no machining,good high-temperature properties,probably high volume to amortize tooling costs. Gets my vote.

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


Resources

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