×
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

Gears in gas powered core drill

Gears in gas powered core drill

Gears in gas powered core drill

(OP)
Were busting teeth  in service
Tested them at 60 Rc,,, so I tempered them at 450C back to 48Rc
Boss flew off handle,,, said they are too soft now
Please advise

My estimate is that 48 is not too soft

Gear mat,l unknown  

RE: Gears in gas powered core drill

Dog, it depends on how they are breaking.  If the problem was the teeth shattering, then dropping the hardness might have been wise.  If the problem is fatigue at the root, then dropping the hardness is likely counterproductive.  If wear is the problem, then dropping the hardness was not the best idea you had that day.  Yet if it was case crushing, causing the surface of the gear tooth to spall, and the tooth to fail soon thereafter, then dropping the hardness was inconsequential.

The advice I could give would be greatly improved if you could say if it was a carburized, through hardened, or induction hardened gear.  Any idea?

RE: Gears in gas powered core drill

At 60Rc it was most likely carburized, but as you say Lee, without a better description of the failure mode it is difficult to advise.

RE: Gears in gas powered core drill

(OP)


Thanks for your valuable time


Will look at failed teeth under microscope

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