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Klaas remmen

Georgian 'Bulat' technology by Zaqro Nonikashvili

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Klaas.

Yesterday, I melted some wootz like Zaqro does it, in coke. It was a little problematic, as I have no way of removing he ash under the crucible.... after about 1 hour I suspect I am getting a very oxidizing fire...cooling was fast due to me leaving the air intake open. Actually I am happy just to have the whole thing survive. The ingot is rough looking and it seems solid.

[

 

Klaas,

Today I melted a sister to the above ingot, the formula is as "the same" as I can do ( my kitchen digital scale is not too good), coke , home made crucible and all . I made an effort to cool the ingot slower by putting it in wool ( thank you Greg ) , a little problematic as the top of the crucible did not get above orange heat . Frankly the coke fire got a bit ugly late in the run.

Jan

Edited by Jan Ysselstein

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Jan,

The hole and opening out was a theory of how the ladder pattern was made. It was put forth by the French writer in the 1800's? I think...I'll look and get his name if you wish.

The long and the short is that it was one idea on how the ladder rungs were formed...because some ingots have long dendrites from the outside of the ingot toward the center and it was proposed that the ladder was the result of these being opened out from the hole.......not the way it was done, but....

 

Niko was simply exploring all the possibilities.

 

Ric

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Jan,

The hole and opening out was a theory of how the ladder pattern was made. It was put forth by the French writer in the 1800's? I think...I'll look and get his name if you wish.

The long and the short is that it was one idea on how the ladder rungs were formed...because some ingots have long dendrites from the outside of the ingot toward the center and it was proposed that the ladder was the result of these being opened out from the hole.......not the way it was done, but....

 

Niko was simply exploring all the possibilities.

 

Ric

 

Ric,

Thanks for that bit..I admire Niko and Klaas for trying it , I do not think I could do it actually. I brought it up because in an earlier post on this thread, Zaqro had explained to klaas, he flattens the larger cakes and has them cut ( with a laser I believe). We are probably all working with different metal and I know what I am attempting to forge would not do well getting stretched.

 

Jan

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Klaas,

Today I melted a sister to the above ingot, the formula is as "the same" as I can do ( my kitchen digital scale is not too good), coke , home made crucible and all . I made an effort to cool the ingot slower by putting it in wool ( thank you Greg ) , a little problematic as the top of the crucible did not get above orange heat . Frankly the coke fire got a bit ugly late in the run. I will melt a third and attempt do do a really slow cool by leaving it in the fire and keeping the fire burning slowly. Please ask Mr. Visser if l am going to be able to apply for class credit on this one. Once I relearn how to forge ingots I will keep you posted on the differences if any.

 

Jan

 

Klaas,

The younger sister is not a twin after all. I mentioned that some of the slag of the first cake was slightly magnetic ( indicating the ingot is higher in carbon than planned and all the reactions did not finish) .

Jan

Edited by Jan Ysselstein

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Hi Jan

 

If you have iron trapped in the glass, you should have an ingot with less carbon, since the part under the glass contains 'no' carbon, and gets protected by the glass from taking more. I always had a small amount of iron in the glass, especially with larger ingots.

 

If you have a nice thick piece of glass covering your ingot, and the crucible did not brake or crack, I believe you made a good ingot. If you made a bad crucible and your glass started to eat through the crucible wall, you will end up with a cast iron ingot, as the liquid metal at the bottom is not protected from the excessive carbon above the former glass layer. I have had that about a dozen times, I noticed molten glass is very agressive for ceramics.

 

Ric; I am thinking of other variables that this way of forging might have.... This I do not know for sure, its just brainfarthing:

Indeed a lot of ingots have dendrites towards the centre, so what happens if you deform these 'normally', they become elognated at the sides of the ingot, and the ones in the middle become compressed. If you forge it like a donut, you will virtually 'compress' all the dendritic structures. What this does to your pattern or banding physics, I don't know.

 

Another thing I noticed is when I am hammering a half-egg shaped ingot flat, the rounded edge at the bottom goes flat first. In this way you are deforming quite a lot of material, and not creating those nasty 'fishlips'. So when you start to stretch the hole, you will already have deformed a lot of material, in a way that is not agressive to the ingot. What that does to the structurs, patternforming... I don't know, but I notice that once I get to the stretching of the ingot, the material is 'moving'. This might have to do with the fact that the ingot stayed at temperatures which allow the cementite to spheriodise slowly.

 

anyways, this technique is hard. I spent three hours of hammering yesterday to get a 13mm hole stretched to 27mm. But the ingot shows no cracks at all, seems like a good one. :lol:

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Oh yes and Jan, If you just turn off your wind, you'll get a slow cooling... I once got back tto the shop after more than 12 hours, and around the crucibles the cokes were still redhot. If you put a lid on your 'furnace' it will go even slower.

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I made a small knife from the piece that broke of my last donut attempt. I hardened and tempered it, it's hard enough to scatch glass.

DSC00412.jpg

 

I got some news from Zaqro, he is busy experimenting with diffrent techniques, with incredible results;

z-01.jpg

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I made a small knife from the piece that broke of my last donut attempt. I hardened and tempered it, it's hard enough to scatch glass.

DSC00412.jpg

 

I got some news from Zaqro, he is busy experimenting with diffrent techniques, with incredible results;

z-01.jpg

 

Klaas,

Looks like things are really moving in the small world of wootz..congratulations to you and to Zaqro ...you for your quick progression and determination, and to Zaqro for getting to that beautiful pattern, like the one of the "ancients". I have always looked at books showing the older blades as examples what to shoot for, but now I will have to look at modern examples as well.

 

Jan

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Hello Klaas!

 

I think you know yet that we will have an "International Georgian Bulat Symposium" during the 12th. BKS Cutlery Days, at Gembloux Belgium ?Dates are from the 11th. to the 13th. of November 2011.

I suppose you will be there with Gotscha and Zaqro !? and a lot of other friends :)

 

See you soon.

 

MVG,

 

Jacques

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Klaas, very nice blade you have there.. continuous pattern and contrast... its good !!!

 

by the way, that bulat that Zaqro has just made is quite lovely.. wonderful pattern and color ... that is extremely nice work

 

i wish i could go to a bulat conference.. that would be an adventure

 

 

take care

Greg

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@ Jan and Greg; thank you for your kind words, they mean a lot to me!

 

@ Jacques: Yes I know :lol: i'm looking forward to the Gembloux BKS days, I will be helping Gotscha with the preparations again as well, so I'll certainly be there!

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@Klaas

 

Thanks a lot.:)

 

I will have a look at all the organization documents that Gotscha send me, but I've not very much time for the moment. I'll do it next week.

I hope to meet you before Gembloux. so we can better organize this evenement.

Gotscha said me you 've yet an American participant?

I'm curious to know more :)

 

See you,

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Hi Klaas.

 

What you think now about donut tech?

Thats nice looking blade you have there.

 

Zaqros pattern looks realy nice, interesting "cuts" on it.... Z ?

What size is the Zaqros piece how about the blade you forge.

 

BR

Niko

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@ Jef, that's what I have been thinking too... just read the Massalski acount in mr Khorasani's book... very interesting!

 

@Niko; the donut tech is hard... lots of work, but i'm down to a 200X 20X25mm bar now, with a nice pattern already... I'm curious about the results when completely forged.

We saw the Z-pattern on a very nice shamshir when Zaqro was in Belgium, seems he liked it a lot and tried it himself.

 

@Jacques: I'll contact you via email!

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I did some more work on my latest donut, here are some pictures. The bar is still quite thick, and I hope to get those #@%*£ dendritical patterns out of it.... Also I attached a few metallographic pictures (Nital etch). Seems I have been forging at very low temperatures (I forge in coal fire), so all the pearlite has become spheriodised cementite in a ferrite matrix. The big blocky cementite are in interdendritic regions, and make up the pattern. I hope I can manage to align this cementite more, and get a more flowing pattern. This steel has some alloying elements (about 10g HSS drill for 1300g steel), unlike my last attempt, which was (theoreticly) completely pure carbonsteel.

If anyone has advise, I am happy to hear it!

Thanks for watching,

Klaas

 

kantplatdetail.jpg

kantbollehamerdetail.jpg

gesmeed5X.jpg

gesmeed10X.jpg

gesmeed50X.jpg

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I did some more work on my latest donut, here are some pictures. The bar is still quite thick, and I hope to get those #@%*£ dendritical patterns out of it.... Also I attached a few metallographic pictures (Nital etch). Seems I have been forging at very low temperatures (I forge in coal fire), so all the pearlite has become spheriodised cementite in a ferrite matrix. The big blocky cementite are in interdendritic regions, and make up the pattern. I hope I can manage to align this cementite more, and get a more flowing pattern. This steel has some alloying elements (about 10g HSS drill for 1300g steel), unlike my last attempt, which was (theoreticly) completely pure carbonsteel.

If anyone has advise, I am happy to hear it!

Thanks for watching,

Klaas

 

[

 

Klaas,

Thank you very much for the micrographs..so interesting. I guess by beating on that pearlite, it becomes really ready to be spheroidized. I would play by converting some of the finer cementite to pearlite again . When looking at the graphs showing the migration ( of carbide formers) out of the dendrites to the IR, the concentration of carbide formers in the austenite first forming is not Zero...I am always concerned about a lack of migration out of the dendrite and competition for carbon by carbide formers in the dendrite and in the IR.

It looks like you need to reduce the thickness by about another 50%, you can just keep going and do the pearlite conversion at the end ( if the little ones do NOT get too big).

 

I have a microscope in hiding from the elements, and this summer I am converting my barn to a dry, dust free, heatable space...now it is just like being outside.

 

By the way will that little camera/microscope work on a mac computer..If so would you post the makers name again? I am aware these photos were done on a big microscope.

 

Jan

Edited by Jan Ysselstein

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Jan

 

I am going to do a heattreatment (hardening and tempering) in the end anyway. To try and make some pearlite first shouldn't be a problem (I hope). Would heating to yellow and slow cooling be sufficient? Before I do that I will make new macrophoto's, I want to know what happens when.

I have a 'Veho 200X' USB microscope, works great on a Mac, but, is not very suitable for metals or metalstructures. First of all, the 200X is a plain lie, this thing goes to about 10X if you ask me. Also you have a built-in LED light. This is very strong and reflects the light on steel in an annoying way. Maybe the new 400X is better.

Edited by Klaas remmen

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Jan

 

I am going to do a heattreatment (hardening and tempering) in the end anyway. To try and make some pearlite first shouldn't be a problem (I hope). Would heating to yellow and slow cooling be sufficient? Before I do that I will make new macrophoto's, I want to know what happens when.

I have a 'Veho 200X' USB microscope, works great on a Mac, but, is not very suitable for metals or metalstructures. First of all, the 200X is a plain lie, this thing goes to about 10X if you ask me. Also you have a built-in LED light. This is very strong and reflects the light on steel in an annoying way. Maybe the new 400X is better.

 

Klaas,

Thanks for the microscope/camera information. I do not have a lot of experience in heat treating wootz to achieve a harder matrix, so I will keep quiet . I do know that the very fine spheroidal cementite will dissolve almost instantly just above the critical temperature. Be cautious about using information based on the experimentation of others ( especially `mine).. go with the text books for the facts. Pretty soon you will have your own pile of experimental data to use as a guide.....for me, the most valuable information has come from disasters, which I seem to be good at creating. There was a period last year when all my crucibles were failing and nothing was being learned, that was frustrating. A problem in using experimental information from the steel industry is, some phenomena we are hoping to induce they were trying to avoid at any cost, so many of their experiments only help us a bit.

I hope you are just doing your school work and not getting suckered in by the wootz spider in that web.

 

Jan

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Klaas,

Thanks for the microscope/camera information. I do not have a lot of experience in heat treating wootz to achieve a harder matrix, so I will keep quiet . I do know that the very fine spheroidal cementite will dissolve almost instantly just above the critical temperature. Be cautious about using information based on the experimentation of others ( especially `mine).. go with the text books for the facts. Pretty soon you will have your own pile of experimental data to use as a guide.....for me, the most valuable information has come from disasters, which I seem to be good at creating. There was a period last year when all my crucibles were failing and nothing was being learned, that was frustrating. A problem in using experimental information from the steel industry is, some phenomena we are hoping to induce they were trying to avoid at any cost, so many of their experiments only help us a bit.

I hope you are just doing your school work and not getting suckered in by the wootz spider in that web.

 

Jan

 

 

Klaas,

I have checked into the little microscope and it does work with my computer, but it appears it is not a zoom but a dual magnification...one at 20 and one at about 400. Good luck with the symposium, good to have on your resume. There is a lot of valuable information in this post so I thought I would keep it going.

Below are two photos of what I have in process, 4 ingots..2 for forging with high expectations and 2 going through the process for information only ( if I had to wait for perfect ingots to learn from, I would still be on my first one). The ingots range from 650 to 1165 grams, one is about to be put into the furnace for annealing ( it is a very porous ingot ) . The little cracked one should forge now after some more time at temp.

Jan

 

 

Edited by Jan Ysselstein

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Klaas,

I have checked into the little microscope and it does work with my computer, but it appears it is not a zoom but a dual magnification...one at 20 and one at about 400. Good luck with the symposium, good to have on your resume. There is a lot of valuable information in this post so I thought I would keep it going.

The one bit I have trouble with is the annealing temperature of over 1100 C. ...

Below are two photos of what I have in process, 4 ingots..2 for forging with high expectations and 2 going through the process for information only ( if I had to wait for perfect ingots to learn from, I would still be on my first one). The ingots range from 650 to 1165 grams, one is about to be put into the furnace for annealing ( it is a very porous ingot ) . The little cracked one should forge now after some more time at temp.

Jan

 

 

 

Hi Jan

 

Why did the ingot crack? What do you do for annealing time and temperature?

Is that clay with ironoxide you put around your ingots?

I'm curious how these turn out!

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Hi Jan

 

Why did the ingot crack? What do you do for annealing time and temperature?

Is that clay with ironoxide you put around your ingots?

I'm curious how these turn out!

 

Klaas,

 

Yes, that is Spanish Red iron oxide..just clay will slow down scaling as well ( just use whatever you coat your blades with prior to quenching ) . Adding Graphite and no red will reduce decarb for about 1 hour and then it is consumed. I do not have furnace control so I chase it between 950 and 1100 C, manually.

 

One small ingot was bad to begin with, but still, it was forged at too high a temperature....the next ingot is forging nicely , it is flat and just being turned on its side. I may cut the next problematic one in half to get more learning opportunity.

I have one more 'good" ingot to forge at the very end.

 

Then back to more melting using 1 formula and make all the variation down stream.

Jan

 

By the way I had posted a lengthy reply just a few minutes ago and it posted..now it is gone ?????

Edited by Jan Ysselstein

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Klaas,

 

Yes, that is Spanish Red iron oxide..just clay will slow down scaling as well ( just use whatever you coat your blades with prior to quenching ) . Adding Graphite and no red will reduce decarb for about 1 hour and then it is consumed. I do not have furnace control so I chase it between 950 and 1100 C, manually.

 

One small ingot was bad to begin with, but still, it was forged at too high a temperature....the next ingot is forging nicely , it is flat and just being turned on its side. I may cut the next problematic one in half to get more learning opportunity.

I have one more 'good" ingot to forge at the very end.

 

Then back to more melting using 1 formula and make all the variation down stream.

Jan

 

By the way I had posted a lengthy reply just a few minutes ago and it posted..now it is gone ?????

 

Klaas,

This photo shows where I am at the moment, I will not be able to forge for about two weeks...I am a little concerned about the forged sample because after 12 cycles there is Zero evidence of a pattern....that could be really good or really bad news. I will remelt the cut ingot and not try to forge it. The other ingot in the photo should be good . These are my first round bottom ingots, I have some crucibles made with flat bottoms and will try to use them up regardless.

 

Jan

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Klaas,

This photo shows where I am at the moment, I will not be able to forge for about two weeks...I am a little concerned about the forged sample because after 12 cycles there is Zero evidence of a pattern....that could be really good or really bad news. I will remelt the cut ingot and not try to forge it. The other ingot in the photo should be good . These are my first round bottom ingots, I have some crucibles made with flat bottoms and will try to use them up regardless.

 

Jan

 

 

Klaas,

A correction, both forgeable ingots have a granular pattern below the decarb surface ( about 3mm thick). The patten still has the implied pattern of the former dendritic structure, many of the grains are a bit rectangular. Below is a photo of the inner transformed structure ( bright) covered by the decarb layer (dark) , of the (unforged) little ingot shown in the bottom photo above.

 

Were you able to move the spheroidal cementite formed by the transforming pearlite? How does that pattern look now?

 

 

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Well Jan, looks nice! thanks for sharing.

 

The pattern of my last pics became much nicer. Almost no typical dendrite forms anymore, but is still a very fine pattern... small bands.

As you can see on my last macroscopic pics, the cementite is moving from in between the bands to the bands. I am going to make a new metallographical picture of the structure now that it is forged more intensly. I hope to see some more breaking down of these large cementite chunks, because that's what seems to be the biggest difference in hostorical wootz and mine. maybe that is due to me not using these long annealing times and temperatures.

 

I'll post the pictures as soon as I have got them.

 

Are you going to use flat bottemed crucibles? I am curious how that turns out. In industry they try to avoid anything that has corners when casting... your casting-structures could make corners prone to cracking.

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