Heat treating 4140

[dgallup]

Is it possible to heat treat 4140 without doing an oil quench? Very small parts, ~ 5mm diameter x 10 mm long. Through hardened HRC 52-55.

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[redpicker]

Is it possible? Certianly. Vacuum heat treating with a high pressure gas quench should be able to do it.

But, that would be much more expensive than an oil quench. Without some type of accelerated cooling, you aren't going to make 50 HRC.

rp

 

[TVP]

I agree with rp, air cooling or fan cooling from the austenitizing temperature will not produce 52-55 HRC. Austempering could be done, but hardness will be lower than 52-55 HRC. More like 43-48 HRC with a salt temperature of ~ 345 C (655 F).

 

[dgallup]

Thanks, we have a furnace set up for nitrogen quench. Just one small batch so cost not an issue.

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.

 

[blacksmith37]

I guess water quenching would be too easy ?