×
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

Case hardness variation

Case hardness variation

Case hardness variation

(OP)
We are doing carbursing case hardening on a SAE 8620 material in an Integral/Sealed Quench Furnace using LPG+N2+Methanol atmosphere. The case depth : 1.5-2.4mm, Surface hardness: 58-62HRc.

We are currently facing a problem:
1. Case depth below specs but surface hardness OK
2. Surface hardness varies between 24-59 HRc in same part.

Currently we found one pc each of above problem in one furnace load (1500 pcs)

Following are questions:
1. We have initiated a containment action of eddy current sorting for low case depth. Is this the best method?
2. We are yet to have a containment action for within part variation in HRc. Is there a right method?
3. What could be root causes for this?

Thanks

SPM


RE: Case hardness variation

Why not start by looking at the microstructure of the soft area to see if it has low carbon or retained austenite which would indicate irregularities in carburization? Until you know the root cause you can't do # 1 and 2.

RE: Case hardness variation

If ur facing a surface hardness variation, eddy current method can't detect this problem correctly.
tell me the configuration where ur finding this problem. whts is the capacity of the furnace? temperature of oil bath? if u can provide all the details, i can provide sme help.


baskar

RE: Case hardness variation

(OP)
Hi Baskargk,

What do you mean by configuration - if it is part geometry, then the part is like a spider. The furnace capacity is 600 kgs. The oil bath temp. is 120 deg.C


 

RE: Case hardness variation

How are you measuring the hardness?
What are the case hardnesses?
You need to do this carefully on prepared samples with low load testing.  You may be confusing multiple issues here.

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

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