Super Quenching

I have recently been reading about an old technique call Super Quenching for hardening low carbon steels lie 1018. The claim is during testing the consistently got hardness over 40 with occasional test pieces testing as high as 48.

In the reference I ran across the want to have us mix up five gallons of quenching liquid.

If anybody has used this technique I have two questions for you.

  1. If I keep the proportions right is there any reason not to just make up one gallon? (I only need to harden one part.)

  1. How hot do I need to get the piece before quenching? Straw? Dull Red? Bright?

Reply to
Bob La Londe
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While I never heard of "super quenching" to harden steel you want to heat it until it is "cherry Red", or non-magnetic - doesn't deflect a compass, or reached the correct temperature :-) depending on what you read. You need to soak the part at specified temperature until if is thoroughly and evenly heated.

The volume of the quench medium needs to be sufficient that the quench medium remains at the proper temperature, i.e., quenching does not heat the quench medium. The medium may range from brine to some form of oil with the brines said to produce the hardest and oil a less hard but tougher temper.

I've never tried to harden 1018 but generally hardening steel (heating it and then quenching it) results in a work piece with considerable built in stresses and usually tempering (re-heating to a lower temperature and quenching) is needed. I have hardened "Drill rod", probably 1090, quenching it in a cold brine bath and the freshly hardened drill bushings would crack sitting on the bench after hardening.

Reply to
John B.

I'd suggest you Kasenite treat the part. Directions on the can. This will give you a real hard surface and maybe just a slight bit of tensile improvement over std. 1018

Karl

Reply to
Karl Townsend

After some more study I decided to go with Cherry Red case hardening. The case hardening is all that's necessary, and the surface hardness is slightly higher than the reported results from Super Quenching. This is for a single use (I hope) cutting tool so the long term life is of no interest. I may save the tool, but I doubt I'll ever use it again. I'll save the files so I can make another one if I have to.

Reply to
Bob La Londe

Not that old at all!

I see you have decided to case harden rather than try to "super quench", but here's some info about "super quenching": The process was devised by a guy named Rob Gunter when he worked for Sandia National Labs about 20 or 30 years ago. He is a blacksmith and was making prototype parts for the scientists at the time. In many cases they wanted a part with "hard" characteristics, but, for whatever reason didn't want to use tool steel. So Rob came up with this "super quench" formula. He has demonstrated its use in dozens of cities around the USA over the years and has many "converts" to it usefulness. It can obviously only be used the cold working applications, since it doesn't take much heat at all to begin to temper the low carbon 1018. I personally have seen him cut some stock off a bar of 1018, form it into a chisel, harden it and then cut another piece off the remaining 1018 bar without damaging the chisel's cutting edge at all.

Here's the recipe:

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For more about Rob:

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Pete Stanaitis

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Reply to
Pete S

Thanks Pete. Looks like most of the articles on this all quote each other. I've read the recipe half a dozen times (and save it in my metal smithing files) so far.

Reply to
Bob La Londe

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