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  1. #11
    Marko Tsourkan's Avatar
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    Excellent post.


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  2. #12
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    Wear resistance contributes primarily to edge holding for slicing. This is where coarse edges also lead to longer edge holding. Coarse edges + high wear resistance + slicing = long edge retention. For push cutting/chopping wear resistance and coarse edges are not very helpful.

    Hard carbides like Vanadium carbides in steels like S30V and 10V contribute more to edge holding than simple iron carbides in carbon steels or chromium carbides in simple stainless steels. However, they make it more difficult to sharpen, especially when the abrasive in the stones are softer than the carbide. The following is a chart of carbide hardness from Crucible:

    HARDENED STEEL • 60/65 HRC
    • CHROMIUM CARBIDES • 66/68 HRC
    • MOLYBDENUM CARBIDES • 72/77 HRC
    • TUNGSTEN CARBIDES • 72/77 HRC
    • VANADIUM CARBIDES • 82/84 HRC

    More carbides does the same thing. More carbides means more wear resistance, but more difficulty in sharpening. And of course there is the balance of wear resistance with toughness and edge stability that will be covered later.

  3. #13

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    Is there any difference in performance if the chromium carbides precipitate out as platelets rather than spheres and is that something that can even be controlled with the tempering or is it basically luck of the draw?

    -AJ

  4. #14
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    Carbide precipitation in tempering goes through a series of stages. In the early stages of tempering (low temp), fine rows of transition carbides are precipitated within the plates/laths of martensite. They look a little like plates. They are usually not what is described when talking about plate-like carbides. Transition carbides are unlikely to b chromium carbides because chromium is a mch larger atom than carbon and so requires more temperature to precipitate out as transition carbides. At higher temperatures the carbides are spherical. Plate-like carbides are not generally created though tempering. They're more generally associated with certain primary carbides (created during solidification not tempering or other processes of precipitation) or upper bainite.

  5. #15
    Hobbyist Craftsman Hattorichop's Avatar
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    Mr. Tanaka's with R2 PM steel is the best performer out of all my knives.

    It gets sharper and stays sharper longer then every knife I own.

    My kikuichi VG 10's

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    VG 10 Hattori forum I use to own

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    I love my Tanaka!

  6. #16
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    +1 what Larrin said.

  7. #17

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    I thought Cr7C3 carbides were spheroidal and Cr23C6 carbides were platelet and that the spheroidal ones came first but I didn't know if that was solid state or during tempering. I may be completely lost though. Thanks.

    -AJ

  8. #18
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    Quote Originally Posted by ajhuff View Post
    I thought Cr7C3 carbides were spheroidal and Cr23C6 carbides were platelet and that the spheroidal ones came first but I didn't know if that was solid state or during tempering. I may be completely lost though. Thanks.

    -AJ
    It's a difference between primary vs secondary carbides rather than really the type of carbide, though the one type of chromium carbide is more likely to be a primary carbide. There's conflicting literature on which chromium carbide that is.

  9. #19
    Mike Davis's Avatar
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    This is a fantastic thread!! Thank you Devin for starting it, and thank you to everyone contributing. I loves educating myself on metallurgy.

  10. #20

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    whoa. I am bookmarking this.

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