AKS 8670

Discussion in 'Heat Treating Forum on KnifeDogs' started by scott.livesey, Jul 15, 2017.

  1. scott.livesey

    scott.livesey Dealer - Purveyor

    Just bought a couple of pieces to try, some for kitchen utility knives and one cleaver. has anyone else tried this steel? any heat treat tips?
    Here is composition:
    C: 0.71
    Cr: 0.43
    Mn: 0.50
    Ni: 0.88
    Si: 0.28
    I was thinking 1550F, soak for 5 to 7 minutes, quench in oil. temper at 300F for utility and 400F for cleaver
     
  2. samuraistuart

    samuraistuart Well-Known Member

    I use it, Scott. Heck, if it's oil quenching I use it! ha ha! Great steel, VERY VERY tough even at 63HRC. Very clean steel, too, works like butter even hard. Sharpens to an excellent edge. Not hardly any wear resistance, obviously, but that's not what this steel is about. Hard and tough...that's this steel's forte.

    I do 1525F, 10 minutes, P50 quench with no issues. Leaving edges thick these days now that I have the grinder to thin down post HT, so I haven't had issue using fast oil on this steel.....yet. I'm doing 350F tempers for kitchen knives and hunters both, coming in at ~63HRC. Spec sheet calls for very high austenitizing temps, not sure why, tho. Cr doesn't begin to go into solution until 1650F, IIRC, so I don't get why the recommended high aus temps. I wouldn't go above 1530F on any simple carbon steel anyway, that's just me. No vanadium, so I would keep the aus temps down. Plus, coming from AKS, no normalizing or cycling needed. Austenitize, quench, temper, done.

    You'll like that steel. I like that it comes in good thickness...or should I say more properly....good THINNESS. .084" is very handy for most all what I make.
     
  3. scott.livesey

    scott.livesey Dealer - Purveyor

    Thanks for the info Stuart. I have plenty of O1 but was looking for something tougher for a big cleaver.
    I bought two pieces 0.084" for kitchen knives and one piece 0.126 for a cleaver. the higher temperatures are from the posting at AKS and the data sheet for Bestar BE86 which I think this steel is. the AKS numbers for composition are in the middle of the composition numbers Bestar gives. Wear resistance really isn't an issue with kitchen knives. For a hard use cleaver, I think 5 degree scandi with 15 degree edge should work fine.
     

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