Easiest stainless to heat treat

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    • Helpful

    Hi Luke.


    AEB-L works nice and easy and gives a fine edge and brillint polish but the HT temps need to be accurate for the best result (can get workable results though) and possibly needs cooling post HT

    N690 is a little more expensive, not much, nice polisher

    X50CrMoV15 is fairly inexpensive, little bit more brittle, edge holding seems fair not excellent

    Elmax is nice to work and does not tend to warp, I like it for folders. It is more expensive.

    S30/90/110V is harder but seems to hold an edge well, I can't get the polish I want from it (110 will dull your sawblades!)

    D2 is pretty good for a resistant (not stainless) tool steel but will rust if not looked after or if stored in a sheath, widely available and cheap, gets v hard but same issue with finish as above.

    RWL34, v easy working, non warping (generally speaking), loves to be polished but all this reflected in price.


    There are others but these are the ones I have used.


    If your forge is fairly closed (bricks etc) you may be able to get an estimate of the temp with a probe (out of the blast), stainless requires a bit higher temps and is a little more tricky,


    You prob know, but you will need some heat treatment stainless foil to wrap the blades in, you will prob get a supplier here or on the web (I got mine in a large roll from the US). Brisa are also a good supplier of knife material. Remember to add a few minutes soak to allow for equalisation since the foil reduces/delays temp build up.


    I have never used air cooling, oil worked well and now I mainly use plate quench, easy, no mess and keeps the folder blades straight.


    Try and check the results of the hardening, (you may do this already, not sure🙂) with a set of hardness test files, they are cheap and easy but only give estimates. If you have your process down and want to know exactly what the HRC is I am happy to test a sample for you as long as you cover postage.


    Good luck and enjoy! Post some pics.


    Ignatius

  • I think it would be a waste of money and time to try to heat treat stainless without a kiln. I don't know any knife maker that heat treat stainless with an open flame and if it was feasible to do that, knife makers would not spend a lot of money on a kiln or send it out for HT.

  • I think it would be a waste of money and time to try to heat treat stainless without a kiln. I don't know any knife maker that heat treat stainless with an open flame and if it was feasible to do that, knife makers would not spend a lot of money on a kiln or send it out for HT.

    You are probably right, I'd love to know how far off the final results would be though.

  • i found some small off cuts of 14c28n destined for friction folder blades id forgotten all about and considered trying to heat treat it myself.

    looking up the data it would seem possible to do at home with good temp control.

    there are different recipes depending on cryo temp

    i'll be using a propane forge...

    in a nut shell...

    if home freezer (-20c) austanize at 1060c for 2.5mm thickness 5 minutes (longer for thicker sections ie 3mm 6 minutes, 3.25mm 7 min, 3.5mm 8 min, 3.75mm 10 min, 4mm 12 min, 4.9mm 25 min.

    quench rapidly in oil

    pop in freezer till temp reached (no soak time required as only needs to reach -20c likely just 2 or 3 hours

    then temper once at 175c for two hours for hardness around 59-60hrc


    i havnt gotten round to trying it yet? but will soon

  • Your forge is quite stable so it actually does look quite doable doesn't it.

  • I am interetsed as to what HT foil does with regard to stainless blades? is it preventing decarb? would it be necessary on blades that undergo a lot of post Ht grinding?

    I am quite uneducated regarding stainless steel but have a HT oven now that will easily do stainless steel (and has argon facility).....

  • yes its pretty stable. also the gas forge has a low oxygen environment, you can see the scale pinging off un protected steel as soon as you take it out of the forge into the air. i use anti scale compound which does pretty much the same as a foil wrap. de carb will soften the steel and the longer its soaked the deeper it'll soften

    if your using an oil quench stainless quenching with a foil wrap will be a hindrance as ideally you'll want the blade out of the foil pouch to quench the only way round that is to have an inert gas atmosphere in an electric forge and no pouch.

    i was under the impression foil wrap was used with air/plate quenching steels like D2.... got some of that somewhere as well

  • It will be an interesting experiment. My experience with heat treating stainless without foil wrap was lots of decarbursation and deep pitting which was a bugger to grind away.


    I am experimenting with a small melting furnace as a salt pot, the results have been good so far but some refinement is needed to get better results.