bainite

[wannabeswordsmith]

I know that if I researched it hard enough I could probably find out the answer to my question, but, I thought I would just simply ask and find the easiest way out of finding what I wanted to know.

 

I know Mr. Clark makes a bainite Katana, and from my limited although growing, knowlege of metalurgy, I thought bainite was an inbetween of pearline and martinsite? This being known, how do you develope a hamon with such blade? I thought the hamon was the boundary so to speak or the transition zone between pearlite and martinsite.

He makes some of the most beautiful and elegant, yet most manly swords I've seen. I was just wondering about the metalurigical enigma's that might surface from producing such a blade.

 

I hope this thread generates some good discussion in helping me figure out my metal urgy questions that I may be scared to ask because of feeling like a total d#@ A#^.

 

Scott

[leonardo daneluz]

Hello!

 

Somebody correct me if I am wrong but Mr. Clark makes blades with a bainitic body and martensitic edge.

Generally speaking bainite develops at low temperatures sustained by a period of time. Each steel has its own time/temperature for bainite. Someway he manages to cool the edge fast enough to form martensite and the body slow enough to develop bainite. How exactly he does that it´s something you should refrain to ask.

Also there is a lot of fun waiting for you in the world of tempered martensite.

Bainite requires a metalographic microscope and a trained eye just to confirm its existence.

[Bennett]

bainite sucks

Edited April 30, 2011 by Bennett

[wannabeswordsmith]

ok, my ignorance, so he does have a martinsite edge then? but the bainite is closely structered to martinsite if I understand right, so that means his sword is more on the toughness side of the scale and wouldn't be closer to the elasticity of pearlite? Would bainite and martinsite have a transition that would produce such great hamons? I would guess so, judging by his work.

[Howard Clark]

The body of the sword is lower bainite HRC 49-51. The edges are tempered martensite HRC 59-61. They are formed in two separate operations.

[Robert Kobayashi]

1

Edited March 29, 2011 by Robert Kobayashi

[wannabeswordsmith]

Thank you Mr. Clark for your answer and others. It is just much for me to understand how the process is done when, I understand the claying, heating, and quenching the entire mono steel blade, but when you say two seperate process'. It sort of blows my mind how you keep the structures within their own properties without upsetting the ballance, and maybe my little understanding of hamons as just a transistion zone of two seperate formations of carbon steel, and how you get a great hamon with bainite closer to the properties of martinsite.

 

I know I may sound a little bit ignorant on the subject and maybe over my head a little. It just was a thought that had been popping up in my head as I tried to understand bainite. Which Lower baintie and upper bainite, I was thinking was somewhat inconsistent (or atleast I thought) and then to reproduce it in a blade with martinsite on the edge, I was trying to grasp it. I will read up on it and thanks for the link Robert.

 

Scott

[Robert Kobayashi]

1

Edited March 29, 2011 by Robert Kobayashi

[Leif S]

The body of the sword is lower bainite HRC 49-51. The edges are tempered martensite HRC 59-61. They are formed in two separate operations.

 

I knew it!

Let me guess. Step 1 is to heat treat the entire blade to bainite. Step 2 is to selectively heat treat the edge to martensite.

You don't have to say anything, Howard. Just nod and smile

[cdent]

Hi Leif,

Please don't take it as any critcism, just wondering, how could someone protect the bainite, and austenitize (sp?) the edge to quench to martensite.

 

I appreciate that Howard gave the Rc specs for his swords. Sounds like amazing control.

 

Take care, Craig

 

edit to add: thanks Robert K. for the link

Edited February 12, 2009 by cdent

[Sam Salvati]

I used to be a kid who thought he knew it all

[Robert Kobayashi]

1

Edited March 29, 2011 by Robert Kobayashi

[kb0fhp]

Hi ya Leonardo.

 

To pick the pepper out of the rat turd, so to speak, I'll tell you what we do in aerospace.

Lower bainite cannot, by spec, be identified by metalographs alone. It must go through a scanning electron microscope to accurately differentiate it from martensite. They are so close in structure.

 

Just a little insight. No steel politics intended. Jerry

 

EDIT: A tidbit;

there is a ditinct, transitional structure between lower bainite and martensite. I don't know the name off hand, but can find it. I do know it is VERY difficult to achieve, as a matter of fact. Laboratory stuff.

 

Actually that isn't quite true Jerry - see the attached picture. Late plates of martensite with red needles of bainite. Good quality metallography and specialized etching technique

Edited March 19, 2009 by kb0fhp

[DFogg]

Wow, that picture is a keeper, thanks for sharing.

[Bennett]

[qu

Edited April 30, 2011 by Bennett

[Bennett]

[

Edited April 30, 2011 by Bennett

[Colin KC]

I think it is done in one operation, not two separate heat treating operations.

 

 

Hmmm, one operation eh Sam? How would that be then?

[Colin KC]

Wow! Lots of edited posts here, am I missing something?

[Alan Longmire]

As I recall, there were some patent or other legal issues, or some such silliness.

[Colin KC]

As I recall, there were some patent or other legal issues, or some such silliness.

 

 

Ah! one of those Thanks Alan

[Howard Clark]

No Alan, no legal issues. I was however compared to someone who was prone to such things, and accused of misleading people because I won't just lay it all out for everyone on the internet exactly how I do things. A couple of people decided that I had to prove to them how it is done, and since I would not provide them free samples they chose to attempt character assassination instead. There is no patent, no legal issue, and no secret. I have told many people how to do it, and some have figured it out on their own. I have the lab work done by John Verhoeven and myself, and speak only the truth about what I do. There was a great deal of non-profit time involved in development of techniques, and lots of not so good swords went to the scrap pile figuring it out. I will not, however, just tell all to be a nice guy. Some genuine damage was done in the real world by folks getting carried away in the heat of the moment on the internet. One friendship was severely damaged, and a couple others dented. And one destined to never be.

[Colin KC]

Thanks Howard, I for one am grateful for alla time you've spent doing it, cos now I know it can be done (& I have my own idea on how to do it, if I ever get round to it it'll be more wasted steel & heartache, but I may reach a similar result from a different angle, I hope )

[Richard Furrer]

No-one, even when the words "pretty please" are used, has to give up the methods they use.

We are in a very open time here in the US and on the net in general and many from Europe and elsewhere come to the US to get information that their neighbor back home will not tell them.

I have seen Howard's testing and they are what he says. He has figured out a novel way of making the blade in the style and method he wishes to use and sells that product....the fact that he does not wish to set out a How-To is a smart move I think....I wish I had done that with some of the stuff I've found over the years.

 

I have noticed a trend, however, where folk are very willing to share what they have been told, but hold close to the chest that which they have developed........I have seen some of my techniques "out there" and when those were built upon the new information was not shared back. I was told by one guy "Hey I worked hard for that information!" when I told him I worked hard for the information I had shared with him he just looked at me with his eyebrows touching and walked away....so he's off my christmas list.

 

You folk are smart..I am sure with research and study and application and testing you to can do wonderful things..including bainitic blades with whatever other structures you wish to include in whatever combinations you can pull off....and when you do I'm sure you will also place a very nice How-to for the rest of us to learn from...I mean hell, its not like you worked for it or anything.

 

Ric

[Colin KC]

...its not like you worked for it or anything.

 

Ric

 

 

I just wanted to highlight that section Ric, not take it out of context, but for those out there that don't unnerstand irony, this should have had a after it

[Alan Longmire]

Thanks for setting it straight, Howard, I'd forgotten exactly what was said.

 

I think many people don't understand that there are certain levels of achievement that require genuine hard-won skill and knowledge, not just stuff read on the internet. I think also that Randal G. said it best when he said something along the lines of "If you are standing beside me, breathing the same air, and I'm showing you how I do something, then it's yours. I'll tell you anything you want to know in person if I like you, but don't expect me to give up my competitive edge and years of hard-earned knowledge to a total stranger online for less than nothing. Do your own damn research."

 

I haven't reached that level yet, but I totally understand.