Help with heat treating 52100

[CR100]

I need some help in regards to heat treating a camshaft of 52100.

- Currently we start with a round 2" billet, its roughly 6.5" long.
- Its rough machined, down to an effective diameter of about 1.25", with an eccentric lobe in the center (hence the 2" bar material). 0.020" is left on all ground surfaces.
- Part is heat treated to HRC60
This is where the problem occurs as the part moves all over the place. Hence the 0.020" left on all ground surfaces.

The heat treating company uses a oil quench.

Any ideas on how to prevent the movement.

 

[dgallup]

Have you tried stress relieving it prior to the rough machining?

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[arunmrao]

Agree with dgallup,remove the machining stresses,post,rough machining. Oil quenching is commonly adopted quenchant.

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[redpicker]

In addition to the stress relieving suggested, you may also need to hang the part vertically for quenching.

rp

 

[CR100]

So the material would come in as rolled. So it could annealed.....

The part is hung vertically when heat treated in oil at 160°.

Have heard a few comments about having it stress relived, the recommended process was,

Rough Turn with .125" of dimensions
Stress Relieve
2nd Operation rough turn within .010" of dimensions
Heat Treat to HRC
Finish grind

Another recommendation was to use oil at 300°F, and another recommendation was to use a vacuum heat treat.

 

[TVP]

Hot oil quenching is one way to minimize distortion during the quenching process. It requires a high flash point oil, and only some heat treaters offer it, but it is a well-understood process with definite benefits.

Vacuum heat treating by itself will not have a meaningful effect on distortion. The reason it was mentioned is because many vacuum furnaces use high pressure gas quenching instead of conventional oil quenching. HPGQ has a reduced cooling rate and therefore tends to reduce distortion.