low tech HT friendly steels?

Discussion in 'Shop Talk' started by inferno, Aug 6, 2019.

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  1. Aug 30, 2019 #61

    inferno

    inferno

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    is the second lower bulge to the right the bainite bulge??

    i'm thinking bainite katanas, bainite :) the magic steel.
    bainite nakiris. :)
     
  2. Aug 30, 2019 #62

    Kippington

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    It's just an example. 15n20 is most likey different as it doesn't have chromium.
     
  3. Aug 30, 2019 #63

    Kippington

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    It is, yes. You'd need to hold the steel above Ms for an extended time, over a day at 250°C for lower bainite (the good stuff). You can see why we just temper martensite instead...
     
    Last edited: Aug 31, 2019
  4. Aug 31, 2019 #64

    inferno

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    yeah of course. getting real 15n20 TTTs is kinda hard. and i'm swedish. and know the tech lingo.
     
  5. Aug 31, 2019 #65

    inferno

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    doesn't sound any non economical at all to me.
     
  6. Sep 4, 2019 #66

    inferno

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    I made a new blade. This time i did it at home. with and angle grinder. then did most of the grinding after hardening at work. and now just now i took it out of the tempering oven.
    This time i used the 80crv2 steel. i did 2x1h at 165C yesterday (had to straighten it but didn't want to do it untempered). and still after this the bahco files just skidded. the grain looked just like the 15n20 one.
    and it was very very hard to fracture after yesterdays temper. had to bring it to work and put it in a really heavy duty vise.

    i did a double quench this time too. and i felt it increased the hardness somewhat. and i kinda felt i had not gotten that even color in the blade before the first quench. the whole tang was not full hard for instance. so i did better the next time. i made a mental note of 850C and non magnetic is like 760C and kinda went from that.

    turned out very well with my stone age gear though.

    BUT this time i could make it all at home!!

    ok lets have some pics of the new knife and the new setup. i have still not finished the first blade though. :) i felt i needed to try this first.

    this is my home burner. its sivert promatic. like 10 years old. with 45kw or so cup on it. new bottle and regulator and hose though. ran it at 2 bars this time but the reg goes to 4.
    new project1.JPG


    my ytong waterglass coated "forge". also ica maxi quench tank. its the best. i'm sticking the burner in from the side about 1/3 in.

    new project2.JPG

    the blade. 80crv2. i can't weld at home so i drilled 2 holes in the tang and bolted it to a flat iron. to be able to manipulate it in the forge. you use what you have.


    new project3.JPG

    after first temp and after grinding at work. plus other angle. its a 50x180 edge, single bevel. perspective change a lot. :)

    new project4.JPG new project5.JPG
     
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  7. Sep 9, 2019 #67

    daizee

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    Cool! Nice work.

    Two quenches is more likely to refine grain than to increase hardness, but depends on the starting state of your steel. If your steel required normalizing, then multiple heating cycles can help prepare it for hardening.

    15N20 is really tough stuff, hard to fracture even at high hardness. That's why it gives such good fine edge stability.

    Re: oils
    Your oil will probably work fine for your purposes. Heating reduces the viscosity and improves convection. Quenching in actual water is quite harsh, and in fact "water-quenched" steels are usually done in a brine solution which reduces surfaces tension and vapor jacket formation, which would actually insulate and slow down cooling. Dunking in your dip bucket water to cool while grinding is a non-issue.

    But I'll mention once again that if you use a food-oil that's known to be the right speed, you won't have to wonder how close to "right" it is, wonder if you're leaving anything on the table, and you won't be burning industrial products into the surface of your eating tools and into the air.

    Can't wait to see that blade finished!
     
  8. Oct 3, 2019 #68

    ForeverLearning

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    Caught up with all of this, hope you keep the updates coming. I am going to add a piece to my next heat treat so I can share the grain size, I've not looked in to that yet.
     
  9. Oct 3, 2019 #69

    ForeverLearning

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    @RDalman would you say Groundflatstock is the best supplier for low volume in the UK?
     
  10. Oct 4, 2019 #70

    RDalman

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    They're the only one I know of anyway
     
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  11. Oct 5, 2019 #71

    ForeverLearning

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    I used them before. Unfortunately used eBay, just checked their website and its near 1/2 the price!
     
  12. Oct 15, 2019 #72

    inferno

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    i have been grinding the blades on stones off and on like 10 minutes every few days. today i was grinding the back side of the 15n20 one on the glass 500. and it was just soo slow so i actually flattened my 220 shappro. and then the back side got flat in like 30 seconds. no shbit. thjis stone has to like 100 times faster than the 500 glass.

    so one back side completely done. next up is the 80crv2 one and its at most 10 minites left on that back side. then i flip them and do the fronts. maybe 2h in total there for both?

    i also started a home utility sword project. you know for situations when you get "unwanted" maybe even violent middle of the night "guests", i made it mostly with an angle grinder on my lawn. 80crv2 too. 5mm.
    I also made a fixture for grinding knives with an angle grinder and welded up a pipe for quenching swords in. i have added an angle grinder to my arsenal of tool too. a blue one.
    swordproject4.JPG swordproject3.JPG swordproject2.JPG swordproject1.JPG
     
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  13. Oct 21, 2019 #73

    inferno

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    Doing some HT-ing now as we speak. tempering.

    and about 1h ago i did some garden hardening too. getting an even temp in 50cm of steel is not exactly easy i found out. its about 10 times harder than a 20cm blade. at least with only 1 burner. ran it at maybe 25% capacity.
    I tried to harden once but noticed the whole blade was not hard after quench, tested with a file. even though it was all non magnetic. obviously it cooled too much between the forge and the quench tank. i basically didn't get it hot enough to account for that. so i had to do it again.

    cranked the burner up to 3 Bar, then adjusted the flow to my liking then pretty much ran it a bit hotter, back and forth, tested it several times with a magnet to really really make sure before it quenched it. and then it came out hard as a rock. all over this time... :) this is important for a sword.

    now i'm tempering it at 200deg C and this will result in something around 60hrc.

    shot some pics too. first pic is what my camera think it looks like at 0 EV compensation, matrix measuring. second pic is what it kinda actually looks like, and then the tempering. some of you might notice the blade has a nice traditional kurouchi finish. they all do when quenching in oil somehow. i wonder why. i also lined the aerated concrete (light concrete) with hard firebricks this time. and that was not in any way better for getting things up to temp, since they soak up a lot of heat. but it saves the isolating light concrete blocks.

    swordHT1.JPG

    swordHT2.JPG


    swordHT3.JPG
     
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  14. Oct 21, 2019 #74

    RDalman

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    Looks like fun
     
  15. Oct 21, 2019 #75

    inferno

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    i'm having fun yes :)
     
  16. Oct 21, 2019 #76

    inferno

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    thinking about doing 1 or 2 "mora" blades out of 15n20 to give away (but more like m eklund style. he really nails the true scandi look imo https://brisa.fi/knife-blades/eklund.html ) . would 165 or so temper be good for this you think robin? I found it incredibly hard to fracture 15n20 even at full hardness. so it must be some tough stuff.
     
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  17. Oct 23, 2019 #77

    inferno

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    looks like i'm in the scandi biz now :)
    spent about 1h at work on these allinall.
    2x 15n20 skinners. tempered at 170. i did these with acetylene at work since i can harden in about 2 minutes or so then. no need for a forge. double quench. seems to have worked out well before.
    quenched in a cut open spray can filled with motor oil :)

    these are 60-70mm or so. working them on the stones now.

    skinners.JPG
     
  18. Oct 23, 2019 #78

    Caleb Cox

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    Very nice! Those Eklund blades are sweet too.
     
  19. Oct 23, 2019 #79

    inferno

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    yeah lets just say he knows a thing or 2 more than i do about scandis. his blades look really racy and bad ass.

    i made these 2 mostly on a 8 inch wheel shop-grinder and i dont really know how to use the wheel well. so i just made them "close enough". and now i'm doing the rest on a shapton 220. But these are small and i can put high pressure on there so its quite speedy getting them to a usable shape.
     
  20. Oct 23, 2019 #80

    Caleb Cox

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    There's definitely an art to grinding on a wheel, check out some videos of Kiku Matsuda grinding, pretty amazing how he uses the different surfaces and angles.
     
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  21. Oct 24, 2019 #81

    Kippington

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    That thing looks amazing! :eek:
    Keep it up!
    [​IMG]
     
  22. Oct 24, 2019 #82

    inferno

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    Thanks!
    I took the sword to work and welded on 10cm extra tang. this weekend its time for a handle, thinking masur. handguard will be Ti. or maybe g10.
     

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