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Post by Deleted on Jun 20, 2020 17:17:38 GMT
Then there are L6 blades that are otherwise properly heat treated, without seeking a bainite property.
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Post by Lord Newport on Jun 20, 2020 22:25:59 GMT
Then there are L6 blades that are otherwise properly heat treated, without seeking a bainite property. Yup..L6 is an excellent tool steel and with a proper heat treat makes great swords even when not in a bainite state. W2 is another tool steel that when properly heat treated makes excellent swords. I had a nice Randall Graham katana in W2 at one time.
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Post by bradc on Jun 24, 2020 8:25:43 GMT
Are you referring to the what appears to be drawn on the sword with a carpenter's pencil? Sorry for delayed response... Yes that is the line. All the current Hanwei L6 baininte blades seem to have that dark habuchi. I have seen (maybe it was here somewhere) pictures of an older Mantis (pre Hamwei fire?) which did not display that dark line. I assume it has something to do with their current heat treatment, but I am very curious if anyone has an idea what is happening at that transition point on Hanweis that makes it so visually distinct (and darkened). I haven't seen anything similar in photos of Howard Clarks so I assume it is unique to the current Hanwei process.
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Post by randomnobody on Jun 24, 2020 8:44:34 GMT
I forgot about this thread.
My guesses come down to either a very sharp cutoff between hardened and less-hard steel, or perhaps a very, very narrow mizukage.
Definitely weird.
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addertooth
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Post by addertooth on Jul 14, 2020 0:51:05 GMT
Knife smith input: L6 is the metal, to achieve Bainite, as versus Martensite is a matter of treatment with L6. Quench it in something cold and you get hard brittle Martensite (which is typical for a lot of swords). Bainite is "quenched" typically in molten salts that are 450-550 degrees (depending on what actual peak hardness you are trying to achieve). Bainite, if actually produced, is less prone to chips than Martensite. I suspect your chipped edge was Martensite, and not Bainite. The test can be confirmed by finding a Rockwell hardness tester (C-Scale), and measuring the hardness of your Ha (edge). The test will produce a dimple in your steel. If it is north of 58, it was Martensite for sure, and not (likely) Bainite, which typically falls in the 56 to 58 hardness range (without tempering). You can temper a Martensite blade to soften it to the same range, but true Bainite will be superior to tempered Martensite in terms of chip resistance.
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Post by severroad on Jul 14, 2020 1:36:35 GMT
Knife smith input: L6 is the metal, to achieve Bainite, as versus Martensite is a matter of treatment with L6. Quench it in something cold and you get hard brittle Martensite (which is typical for a lot of swords). Bainite is "quenched" typically in molten salts that are 450-550 degrees (depending on what actual peak hardness you are trying to achieve). Bainite, if actually produced, is less prone to chips than Martensite. I suspect your chipped edge was Martensite, and not Bainite. The test can be confirmed by finding a Rockwell hardness tester (C-Scale), and measuring the hardness of your Ha (edge). The test will produce a dimple in your steel. If it is north of 58, it was Martensite for sure, and not (likely) Bainite, which typically falls in the 56 to 58 hardness range (without tempering). You can temper a Martensite blade to soften it to the same range, but true Bainite will be superior to tempered Martensite in terms of chip resistance. Thank you for the technical explanation in a way that made sense! Curious, in polishing the middle section (unfinished dark, rough stripe), it almost seemed like rubber was mixed into it? It took serious effort to polish through it, and it literally blackened the stones with what seemed like sticky rubber once I scraped it off the stones. Does that fit with L6? Your description of a martensite edge seems correct. Possibly geometry as others have pointed out, but it didn't chip in a way I've ever seen steel chip really. It shattered almost like Obsidian glass. A couple of millimeters off the original edge, now it's very strong! It's standing up quite well to harder targets. Thank you again for your response.
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addertooth
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Post by addertooth on Jul 14, 2020 1:50:29 GMT
Really hard steel can shatter like glass. I had a blacksmith file (large coarse teeth for hogging out metal while it is still cherry hot). It was supremely hard (probably pushing Rockwell 62 on the C-scale). It got dropped to the floor, and shattered like it was un-tempered glass. It produced jagged shards, which would have been a nightmare if my feet were bare.
I cut bottles (and other objects) all the time. With years of using swords, I learned that edge alignment is king. A light swipe will cut through most things if your edge alignment is within 1 degree. A strong swing with bad edge alignment does create risks. The simple measure of good alignment is simple. If you swing at the bottles, cut through, and the bottles do not move in the slightest (other than the top potentially falling off), your alignment is good. If the base of the bottle/jug moves, then you have edge alignment issues. If the base of the bottle falls off your cutting table, then you have Serious edge alignment issues. When I say bad edge alignment, I mean your swing is not at the same angle as the plane of the blade. A quiet cut, is a good cut, a loud cut is a sign that something was off.
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AndiTheBarvarian
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Post by AndiTheBarvarian on Jul 14, 2020 4:24:15 GMT
CAS Iberia say that the edge of their bainite blades is martensite, the blade above the hamon is bainite, not the edge. So the edge is as brittle as every martensite edge can be.
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addertooth
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Post by addertooth on Jul 14, 2020 5:12:11 GMT
Really hard steel can shatter like glass. I had a blacksmith file (large coarse teeth for hogging out metal while it is still cherry hot). It was supremely hard (probably pushing Rockwell 62 on the C-scale). It got dropped to the floor, and shattered like it was un-tempered glass. It produced jagged shards, which would have been a nightmare if my feet were bare. I cut bottles (and other objects) all the time. With years of using swords, I learned that edge alignment is king. A light swipe will cut through most things if your edge alignment is within 1 degree. A strong swing with bad edge alignment does create risks. The simple measure of good alignment is simple. If you swing at the bottles, cut through, and the bottles do not move in the slightest (other than the top potentially falling off), your alignment is good. If the base of the bottle/jug moves, then you have edge alignment issues. If the base of the bottle falls off your cutting table, then you have Serious edge alignment issues. When I say bad edge alignment, I mean your swing is not at the same angle as the plane of the blade. A quiet cut, is a good cut, a loud cut is a sign that something was off. What kind of bottles do you cut? So you are claiming that poor edge alignment, with a properly tempered steel blade, much less an L6 banite blade, will cause edge damage while cutting (or batting) a plastic water bottle full of water? BTW, why say poor edge alignment instead of piss poor technique or an absolute lack of hasugi? No, you will note I did not say a plastic bottle can damage a blade. (that was a claim from the vendor who sold them the sword, not mine). No need to put words in my mouth, I am certain I can say something crazy on my own. Some people start with bottles, before they try something more substantial. Good form is important to learn early; I am trying to encourage basic techniques to ensure good form with an easy medium (bottles). Practice does not make perfect, only perfect practice makes perfect. I normally try to use simple language to describe things (when possible), and often explain words *in case a novice stumbles upon the thread*. That is why you didn't see me use Hasugi or tachikaze (the sound of a sword cutting through the air) in basic explanations. It smacks of speaking with ego, rather than speaking to teach. Don't get me wrong, when it is merited, or the intent is to build the vocabulary of the reader, I will use the classic terms. But, I will immediately help define the word. I remember when I first came to this forum, and felt like I was swimming in a language site, rather than an educational one. Certainly not everyone spoke in this fashion, but some did.
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Post by treeslicer on Jul 14, 2020 6:01:27 GMT
CAS Iberia say that the edge of their bainite blades is martensite, the blade above the hamon is bainite, not the edge. So the edge is as brittle as every martensite edge can be. So, you're telling us that severroad stopped getting chips because he polished the martensite off the edge? Well, I guess that's one way to "fix" it.
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AndiTheBarvarian
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Post by AndiTheBarvarian on Jul 14, 2020 6:03:39 GMT
A good TH kat edge shouldn't chip!
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Post by treeslicer on Jul 14, 2020 6:10:28 GMT
A good TH kat edge shouldn't chip! Through-hardened katana.............yup, you're a barbarian, all right.
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AndiTheBarvarian
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Post by AndiTheBarvarian on Jul 14, 2020 7:29:44 GMT
I confess, but at least one without a chipped blade!
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Post by Lord Newport on Jul 14, 2020 14:02:41 GMT
What kind of bottles do you cut? So you are claiming that poor edge alignment, with a properly tempered steel blade, much less an L6 banite blade, will cause edge damage while cutting (or batting) a plastic water bottle full of water? BTW, why say poor edge alignment instead of piss poor technique or an absolute lack of hasugi? No, you will note I did not say a plastic bottle can damage a blade. (that was a claim from the vendor who sold them the sword, not mine). No need to put words in my mouth, I am certain I can say something crazy on my own. Some people start with bottles, before they try something more substantial. Good form is important to learn early; I am trying to encourage basic techniques to ensure good form with an easy medium (bottles). Practice does not make perfect, only perfect practice makes perfect. I normally try to use simple language to describe things (when possible), and often explain words *in case a novice stumbles upon the thread*. That is why you didn't see me use Hasugi or tachikaze (the sound of a sword cutting through the air) in basic explanations. It smacks of speaking with ego, rather than speaking to teach. Don't get me wrong, when it is merited, or the intent is to build the vocabulary of the reader, I will use the classic terms. But, I will immediately help define the word. I remember when I first came to this forum, and felt like I was swimming in a language site, rather than an educational one. Certainly not everyone spoke in this fashion, but some did. I am sorry for my confusion on who was claiming a water bottle could damage an edge on a blade, that was CAS Iberia in the OP. After posting, I realized my error and deleted the post, obviously not soon enough. I went back to read the thread in its entirety and lost track of who said what. And you are right, only perfect practice makes perfect. Learning the proper nomenclature and studying what that nomenclature means is a building block of perfect practice as is studying under a sensei who can physically observe what you are doing to correct you. As far as nomenclature, google is your friend as is finding a sensei who can instruct you. That said, videos can very useful both of you and your sensei when learning kata.
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addertooth
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Post by addertooth on Jul 14, 2020 19:19:15 GMT
Lord Newport,
I largely agree with you. Your points are valid. We must remember that some members live far enough from a large city, that finding a Sensei to assist them can be tough.
Addertooth
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Post by Lord Newport on Jul 14, 2020 19:33:48 GMT
Lord Newport, I largely agree with you. Your points are valid. We must remember that some members live far enough from a large city, that finding a Sensei to assist them can be tough. Addertooth And that's why traveling to seminars, study groups and use of legitimate instructional videos produced by sensei can be helpful when living out in the sticks. Using a katana to play whack-a-mole with various targets in the back yard is NOT training. I do not feel that the whack-a-mole crowd are knowledgeable enough to review / evaluate the performance qualities of a Japanese style sword either. There is a huge difference between studying technique and "training". Training results in committing correct technique to muscle memory, they rest is just playing in the backyard. Buying a sword does not make you a swordsman/martial artist any more than simply buying gun makes you a tactical operator or buying books make you literate and educated.
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