Quench oil

[ragnik]

Hi all,

This is a simple question but one that has been crossing my mind! I am doing my own very basic heat treating, at least learning to do it. I am using 1084 steel, I am wondering how much oil do you need to quench it in is there a minimum amount? Seems to me the more you have the better. A small amount of oil would heat too much is this correct??

Thanks

Ross

[Ray Rogers]

That is a good question. I read some kind of rule of thumb about that somewhere but it has slipped out of my little pea brain already.

My quench tank is a 4" diameter pipe about 3 feet long. It has an electric heating element in it so I can pre-warm the opil to any temperature I want. This preheating, it seems to me, is a more important detail than how much oil you have.

Mind you, I'm only guessing but here's how my thinking goes on this: the transformation in oil quenched steels requires that steel at a non-magnetic temperature be quickly brought to some temperature considerably below that non-magnetic temperature. Generally, somewhere between 600 and 800 degrees is enough if memory serves. Any cooling below that doesn't have much effect on the transformation.

Even in my skinny tanks this temperature drop is achieved very quickly. I base that conclusion on the fact that my oil doesn't boil or catch fire for more than a second or so. If the oil was still hotter than about 500 degrees (it's flash temperature) it would burn persistantly.

Granted, I might benefit from having more oil around my blades. But, I think it does illustrate that you probably wouldn't gain much by quenching in a 50 gallon barrel of oil ....