Receiver heat-treating question.

[Stevo]

Can anyone give me a ballpark figure for the maximum temperature a steel firearm receiver would reach when being heat-treated?

Thanks.

 

[guntech]

What part of the heat treating? The hardening or the tempering? What is the composition of the steel?

 

[Stevo]

Good questions. My knowledge of heat treating with respect to guns is pretty minimal so I can't answer the questions.

I was just looking for ranges of typical temperatures a receiver would encounter.

 

[sunray]

Hatcher's Notebook has a whole chapter on the subject. Early Springfield 1903, Class C steel, receivers, only, were heated in bone to 1500F and held there for 4 hours then quenched in oil. The double heat treat had this done, then re-heated to 1300F and oil quenched. This made the outside hard, but not the inside. Then they were heated to 350F to soften the outside a bit.
Different steels are done differently, of course.

 

[Stevo]

Thanks!

 

[trevj]

Good questions. My knowledge of heat treating with respect to guns is pretty minimal so I can't answer the questions.

I was just looking for ranges of typical temperatures a receiver would encounter.

It would depend entirely upon the particulars of the material used for the receiver, the usage it was intended to have, and a host of other things.

Sorta answer is, that the heat treat given to the Springfield as the post above, will cause some materials to become grenades when the first round is fired (IF the part survives the quench at all), while it will have no effect whatsoever on other materials.
The Springfield was made of a low carbon steel, and was case hardened for strength and wear resistance. And lots of them got a reputation for blowing up anyway, due to poor heat treating.

To really have a clue, you need to know the exact material, and the strength/hardness/etc. goals required, in order to accomplish anything useful.

Short answer. Typical temperatures a typical receiver would encounter, would be however cold it gets where a person hunts, up to however hot it will get sitting in the rear window of a parked truck . Beyond that, it's a crapshoot to give you any other answer.

Cheers
Trev

 

[Claven2]

You need to know the exact composition of the steel, the properties of the quenching agent, and you need an engineering understanding of heat treating and annealing alloy steels.

It would also GREATLY help to have the phase diagram for the alloy in question (and know how to read it) along with the time-temperature-transformation diagram. This will, among other things, help you target the desired hardness.

I would suggest this link as a good primer on what is involved:

http://www.asminternational.org/content/ASM/StoreFiles/ACF180B.pdf