Good Ol' 1084

KCorn

KCorn

Well-Known Member
I have recently been playing around with some of Aldo's 1084. Can somebody tell me what the best way to heat treat this steel is? I have been heating to non-magnetic (a shade over) and quenching in canola oil heated to around 130 degrees. I tempered at 400 for an hour. Did not do a second tempering. The blade was tested with the rope cutting test. 1/4" rope. I was able to cut about 3 feet of rope cutting about 1/4" off at a time. After about 3 feet the blade would no longer shave hair. Is this all that can be expected out of 1084 or do I need to change my heat treat? Thanks for any replies!
 
For greater edge retention via strength and abrasion resistance lower you tempering temp to 350-375F. And it would be better to do two cycles for a total of 2 hours. Rope was never my favorite test medium as it can produce very inconsistent results, but then when cutting a medium such as that expectations vs. results are all relative. There are some who favor it because of that, and without standardized results they can apply it to their subjective ideas of performance.
 
Great advice. I appreciate all of the input. Why do some steels benefit from a 2nd tempering cycle and some do not?
 
KCorn said:
Great advice. I appreciate all of the input. Why do some steels benefit from a 2nd tempering cycle and some do not?
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Any basic blade steel benefits from 2 hours of tempering, I haven't done much testing to richer alloys but 1060, 1075, 1080, 1084, 1095, W1, W2, 5160, 52100, O-1, L6, 15n20, and few others all benefit from a homogenizing effect of more than one tempering heat for a total of around 2 hours. Lower temperature with longer times seem to work better for maintaining higher hardness as well as toughness.
 
Would there be any difference in tempering for 2 one hour sessions with a cool down in between vs just a 2 hour temper?
 
KCorn said:
Would there be any difference in tempering for 2 one hour sessions with a cool down in between vs just a 2 hour temper?
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It would appear so, there are transformations/precipitations which occur in the temper heating and cooling cycles which are homogenized by the cycling. Also the richer the alloying the more that blade will benefit from fast cooling from the tempering cycle, this is somewhat the case with TEM (tempered martensite embrittlement) but very much the case with TE (tempering embrittlement) which occurs at much higher temperatures.

But of greater benefit is the ability to walk in the exact Rockwell you want.
 
No, there is no reason for triple quenching. There's a lot of hype about the practice but all it does is make the process more complex and exposes the steel to microscopic cracks where plate martinsite plates meet with each quench not to mention outright quench failure. It is far better to match the steel that you use to the equipment that you have to heat treat with and to give the strongly hypereuticoid steel a longer soak at around 1450-1475°. Something like 1084, even though hypereuticoid, has a low enough carbon content that over saturating the ausinite and causing retained austinite is not that much of a problem. Steels like 1095, 52100, and high carbon W series steels need go heat control for longer soaks.

Doug
 
Heating and cooling in any controlled fashion, even when quenching is added, can refine grain, but grain size is but one part of the equation, and a larger part is carbide size and distribution. Not only are carbides not effected by the quenching shtick they are not even present in the 1084 if all was done right. So all you are really doing is grain refinement. I feel you are better off to do this before the hardening operation in a way that will optimize things for the final heat treatment and be done. 1084 just doesn't have all the quirks of other steels that may require convoluted or complex ways of coping with them under less than adequate circumstances, 1084 is very user friendly and will give you what you want without much effort at all. There are good things that quenching can do for steel but there are plenty of bad things it can do as well, I notice those who really like to overdo the quench never like to talk about the latter very much.
 
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