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For those that havn't hardened 01

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  • For those that havn't hardened 01

    It's pretty simple all in all.

    We heat to 1450-1500 (cherry red) and hold to equalize as need be. You don't need fancy equipment, we just work with what we have which is an old old rebuilt muffler furnace. We do tend to keep the envornment fuel rich in an attempt to minimize decarb.

    Then quench in oil. We happened to have a 5 gal bucket of quenching oil and mixed at 10-1 with water as called for on the label. In the picture below you'll notice what sort of looks like a turbo, thats the air pump for the muffler furnace, with a high tech swing gate (hand powered) for the fuel / O2 mix

    The two pins were doing in the photo's are .393 x 1.625. and as such are easy to handle. These as quenched, rockwelled at 63. Their use called for 63 at the tips and tempered back 35-45 on the backside. Below you'll see them as they are right out of the quench. I've found with O1 that the mottled Grey Black you see generally indicated a good hardening temp. not as of yet has a piece that looks this way failed to be on the mark for hardness.

  • #2
    Then it's time for a cleanup and temper. Seeing as we don't have the best of equipment for tempering these were first cleaned (wire brush in a pedestal grinder) and then tempered with an AO torch by color.

    This little project took maybe an hour in total, with diameter tolerances at -.001 + .0000 .


    • #3
      I read somewhere that you are supposed to temper the part ASAP


      • #4
        One should really go with tempering right after the quench, in fact Crucible ( we work with Crucible steels) calls for a quench to 150F and temper from there. I don't , unless it's die parts, worry too much on that. Die parts, mostly A2, D2, S7, get sent out for professional HT.

        For those that havn't looked, go check out Crucible Steel's Information pages

        Not only does it tell you about all different kinds of steel and alloys, it gives relevant information on HT, etc. Wonderful information to be had there.


        • #5
          Just an additional small pointer for those who haven't hardened before.
          I've always found that "cherry red" is a somewhat mis-leading description of the temperature colour involved, and I think that 'bright orange' or 'cooked carrots' gives a far closer comparison.



          • #6
            Color depends on lighting really. When I describe a cherry red it's definately less than a "bright orange" in a darker space. We work in a darkened area with low light so cherry is pretty close to cherry. Bright orange is getting up above 1750F. It's one of those things that you kind of have to play with unless you have a temp readout. We do have a readout and these were hit right at 1500, although the pictures don't show the steel quite as it looks to us on the spot. I guess the basics come down to this, you want the low side of the correct temp range as going overboard can at times cause other problems. But Peter is right, "Cherry Red" can definitely be misleading. Take and play some with some small chunks to get a feel for it before you jump right in and try to HT an item you intend to use.
            Last edited by Walter; 11-22-2009, 06:21 AM.


            • #7
              There's different sorts of cherries........ The temp reading should be "it". But even that is misleading unless you hold the part long enough to get the entire thing to temp and soaked long enough for all conversions to happen.

              Keep eye on ball.
              Hashim Khan


              • #8
                "Cherry Red" :-)
                Hasn't anyone here but me eaten "Oxhart" or "Bing" cherries?

                I just can't help stirring the pot a little bit. :-)


                • #9
                  So what your saying is I should do my heat treating outside in the middle of the night? Awsome. I love excuses to work (quitely) at 2am.
                  Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.


                  • #10
                    Metal can look like it is very hard,and can still be soft as butter.


                    • #11
                      So that's where I left my cigs and lighter.