Can Carbonitrided parts be tempered?

[mewhg]

We had some failures in 4mm x 23mm pins that were either carburized or carbonitrided to about 60 HRC. Pins are 1215 steel. Failure was when pins were placed in bending which we did not think was going to happen in the application.

Pin have been redesigned with 4140 @35 HRC and are working much better.

However, we have a bunch of the 1215 pins left over that we could use for non-critical applications as long as we could lower the hardness down. We call out carburizing on the dwg but the screw machine shop thinks their heat treater carbonitrided the pins (no records).

If carbonitrided can the pins be tempered back down?

 

[TVP]

Yes, carburized and carbonitrided parts can be tempered.

 

[TStaples]

I have successfully annealed carbonitrided, and nitrocarburized 1215 and 2.5% Silicon Iron components, to "undo" the case hardening. I've seen a slight degredation of the surface finish on some of the parts, but overall, they were quite usable.

-Tony Staples

http://www.tscombustion.com

 

[mewhg]

Ok, thanks a lot for the replys.

I hope I can get these pins down to 40 HRC. They are black oxided now so we will probably glass bead and refinish.

 

[Steve898]

It's worth a try. The more nitrogen in the case, the less response to temper, if there's a lot, then they will still be brittle after 1100°F. But you won't know unless yo try.