4130 HRC45-49
4130 HRC45-49
(OP)
Well in this thread {thread330-123117} I described a problem encountered in the production of a set of prototypes. Teh customer was informed of the problem with carburization. Engineering data was exchanged and the print was updated as far as the material call out.
Just to re-hash:
4130
50mmX15mmx6mm
is 45-49HRc too high of a spec for Q&T of this size of part? I would like an oil quench to reduce the severity, however normally all we do is supply the material type and the final required hardness.
thanks.
(yes I've checked the TTT curves this time.
Just to re-hash:
4130
50mmX15mmx6mm
is 45-49HRc too high of a spec for Q&T of this size of part? I would like an oil quench to reduce the severity, however normally all we do is supply the material type and the final required hardness.
thanks.
(yes I've checked the TTT curves this time.





RE: 4130 HRC45-49
RE: 4130 HRC45-49
300F 50-52 HRC
400F 47-48 HRC
450F 45-47 HRC
725F 40-43 HRC 180-200 ksi double temper
800F 36-40 HRC 160-180 ksi
1050F 27-33 HRC 125-145 ksi
In aerospace and military applications 180-200 ksi is maximum allowed for this steel.
Don't carburize unless you want over 53 HRC.
You can successfully harden this part in oil and temper to 45-49 HRC. It will harden about 1/4 inch deep all over.
RE: 4130 HRC45-49
Do you suppose I need to specify the full heat treat requirement or can I just spec my final hardness? Or should I write a general internal specification (thats what was done for the raw material order)?
RE: 4130 HRC45-49
I not a metallurgist but I recall that between 220ksi to 260ksi the 4340 alloy is brittle. May be the same is for 4130 beyond 200ksi which limits it to the maximum 180-200 that MIL allows. Maybe one of the metallurgists in this forum can respond to this issue.
RE: 4130 HRC45-49
I would specify the Q&T heat treatment in your general specification. I never like to specify just hardness.
RE: 4130 HRC45-49
I gues then I'll start writing the spec.
(on the toughness/SCC issue: This is the hot side of a specialized compressor, there is absolutely no chance of SCC, and any impacts should be relatively low energy since they can only occur at the initial start.)
RE: 4130 HRC45-49
RE: 4130 HRC45-49
(4130 is really hard to find, but available; or should be, I think that the military is buying it all up for armor right now though)