'Konasamudram' Process

[Charles dP]

Thanks Jan and thanks for sharing all this. I hope to one-day also try this path and will surely be looking to this thread for help.

[Jan Ysselstein]

Charles, I see ;you are in Romford...I just got back from a trip to Scotland with a few days added to Oxford and a few in London.....saw lots of beautiful steel. The Japanese galleries and the Persian Galleries were closed in the British Museum for renovation....I did see some good blades in the V and A and the Wallace Collection.

[Charles dP]

I’m going to have to make time and go see all of them. You know how easy it is not to do something that’s right on your doorstep 

[Jan Ysselstein]

We are beginning the forging process and so far so good,, I am forging two ingots at a time and have gone to about 8 cycles..still using hand hammers. The pictures below show the cementite not yet dissolved and converted to ( blank, as I am not sure ). Some of the areas now looking bright and white will eventually lose the cementite and turn into the pearlite matrix.Some of the bright cementite has not gone into solution yet. 

So we may actually be done sooner that I thought...Meanwhile I have prepared some crucibles specifically for making "wootz" using bloomery iron and an organic carbon source .  The demo will clarify the difference between wootz and crucible steel made by co-fussion. 

 

 

 

Edited July 8, 2018 by Jan Ysselstein

[Vern Wimmer]

It's like having your favorite mystery writer sending you their latest novel.....one chapter at a time as they write it. Except this isn't a "whodunit" it's a "howdunit" .

 

[Jan Ysselstein]

Not only the reader may not know who done it but the writer has no clue either . I am testing some ideas that may not be valid,  it is fun trying..if I have to adjust my thinking down stream, I will but not yet.

 

[Jan Ysselstein]

I thought I would add a couple of pictures which ask the question..where is the carbon? This material should be 1.6-1.8% Carbon...and I would prefer to have it everywhere other than in primary cementite or heavy grain boundary cementite....I want the carbon to be diffuse and begin to form a pattern over the next 20 or so cycles....

The pictures show a standard ( Normal)  dendritic pattern...the cementite is almost completely dispersed ...it was in the now dark areas. I still have a ways to go and may not be able to dissolve 100% of the coarse cementite...at 2.% carbon this would be much more difficult to do.

 

Edited July 9, 2018 by Jan Ysselstein

[Vern Wimmer]

Forgive me if i am way off base here but my scientific knowledge is a little short.

I recall reading somewhere in an historic reference, perhaps from this thread, that the "old" makers sometimes packed their ingots in clay and left them in the forge for days while they worked on others. Not knowing a blinking thing about it I wonder if, suppose the clay were of the right content, say iron in it, that the thermal cycling encouraged carbon migration from the steel to the clay in that sealed environment and distributed the, what seems to be excess to start, carbon more uniformly?

Just a question from completely outside the process looking in with curiosity.

Edited July 9, 2018 by Vern Wimmer

[Jan Ysselstein]

Yes , I have read something like that as well...some clay covered and some bare...I have not read about the several days in the forge ( Al Pendray  demonstrated this process in a video posted here ). I have read 2-4 hrs at high heat sometimes 2 or more times. I assume they were moving the carbon to grain boundaries and calling that look "mottled". 

My challenge is to get a routine sequence established which gives a high probability of success. After that I can take any element of that sequence and play. Looking at the iron in Museums,  the blades are large and many have almost no defects , indication very good ingots and forging practice. The main theme is learning about iron and steel. When working with these materials over time , lots of little details come into view. These details  are shared with the makers of the past ( unavoidable).  

One of the two ingots forged yesterday seemed more willing to crack than the other..I will try to find out if the current structure is playing a role or is an indicator....did I not soak that ingot long enough....I soak without clay as my furnace produces very little scale at that temperature. 

[Vern Wimmer]

I also think I remember from the video that Pendray coated his ingots with iron oxide before heating and initial forging. I cant help but think that encouraged carbon migration through the ingot and into that coating. Perhaps, just in my ignorant way of thinking, the act of the migration during the forging somehow makes the high carbon ingot easier to forge without cracking? It would seem to me that if carbon was, literally jumping from the ingot to the coating that it is breaking it's boundaries on the surface of the ingot and affecting the pliabilty/malebility of the surface of the ingot.

I dunno, just random thoughts of a primate with opposable thumbs.

[Jan Ysselstein]

The main thing I am absorbing from Pendray   and Verhoeven is ..the alloy composition and the D.E.T.    the rest for me is work details...we all have slightly different work details and seem  to be much more attached to them than we think. I will be getting back to the completion of this project next week and thought I would show a couple of picture of a bar I am working on. I find this bar interesting because it is about the size of the bars Verhoeven purchased from an Indian ( as in India ) armory on several occasions, 5/16" thick and about 6"long. The feature I like is the areas of light and dark are about equal..the negative is the dendritic patterns are rapidly becoming hard to find and may be gone by the time I finnish forging. I want dendritic evidence in my final pattern ( a matter of personal taste ).  

The field width is about 7mm..I expect the areas to roughly triple in size....the pics look fuzzy but the contrast is very good between light and dark.

Edited October 16, 2018 by Jan Ysselstein

[Joshua States]

Hmmmm…….Careful with that axe Eugene.

5/16 by 6. That should be enough for a decent blade, or are you going to try to weld this to another piece? Is that even an option?

Edited October 18, 2018 by Joshua States

[Jan Ysselstein]

I hope to just forge it out and follow it with the microscope. I think I am out of the residual fragments of large carbides..that is a big deal for me as I like a high carbon content. I have taken all the old "wootz" or crucible steel experiments and broken them into bits for steel showing a strong hamon ....I hope. So the whole process from picking ingredients to etching needs constant adjusting for a better result. I should make a little progress this Winter.

 

[Jan Ysselstein]

I hope to just forge it out and follow it with the microscope. 

pw3

[Jan Ysselstein]

We are at the next forging step mot much material left but all looks good..we have forged at a high ( too high ) temperature and too much has gathered at the larger spheroidized  particles. IT looks good but I will try to redistribute the carbon. If that works I will have a good path to a nice looking crucible steel. To get dendrite remnants that are very recognizable I will have to go another route.

 

 

 

 

 

Edited October 20, 2018 by Jan Ysselstein

[Jan Ysselstein]

After a little more forging, we now have this structure and it is creating a problem as even though I do not have the very large cementite fragments ....some of the cementite is getting much larger than neighboring ones..I am targeting a more even distribution of the spheroidal cementite. Next steps are to grind off some serious decarburization  on one side and do the finish forging at a lower temperature and to a lower  temperature..

Edited October 21, 2018 by Jan Ysselstein

[Jan Ysselstein]

All the scale on the sample has been removed.....still a little grinding to be done to get at the decarburized area shown in the photo. Though the above photograph field is 7 mm wide the photos below are 13mm wide and give an idea of what the pattern me become. The photos below are posted because I want a good record of what is going on and be able to trace to all back. The two microscope photos ( 13mm field ) show a lot of carbon finely spheroidized  and a lot of larger carbon  both are cementite...we will try to dissolve both materials ( cannot do one without the other ) and see id we can get one type of cementite to form...right now we have 2. 

 

 

Edited October 22, 2018 by Jan Ysselstein

[Jan Ysselstein]

Now we have chased some of the cementite to the area containing the micro alloys ...we still have a long way to go as the photo shows a lot of cementite still in the areas that are converting to pearlite. I have what i need from this post and consider it finished....now to some new ingots. I may post a photo if I get back to working with this sample.

[Jan Ysselstein]

Near the end of page 6 off this thread are two ingots cut in half...I just found them while cleaning up around my charcoal forge. These slices are pretty rough and will be forged only to test the forging sequence I am practicing for a couple of really good ingots ( I will show them when I forge them ) . Here is a picture of the inner surface of  one of the slices as we proceed to start forging....the dark areas will be bright and the lighter areas will become dark ( black I hope )

Edited March 19, 2019 by Jan Ysselstein

[Jan Ysselstein]

The two large dendrite pictures just above do not belong to the cut ingot..the dendrite pictures belong to a half an ingot I hope to forge tomorrow. The cut ingot forged quite well , both halves have a very strong dendritic appearance. If I can drag some pictures into this post I will. We are at about 3/8 inches thick, cementite is gathering at the proper place and I will forge to a very flat sheet. The pictures show cementite gathering but the dendrites still recognizable are white...because they are mostly ferrite and will not show any color until later. The screens here and of the large dendrites are 7mm wide. Tomorrow I will forge some odds and ends ( fragments saved from failed runs ) caused by crucible failures.

 

 

 

 

 

 

 

 

 

 

Edited April 10, 2019 by Jan Ysselstein

[Joshua States]

I just went back and cruised through most of this thread. 4 years of experiment and effort. I am seriously impressed.

I also don't really believe you when you say you will soon end this thread.

Edited April 13, 2019 by Joshua States

[Jan Ysselstein]

Thanks Joshua..

This topic provides me a lot of pleasure . I see the making of a steel , like the ones most admired in history...as a challenge . If we look at all the steps involved...crucible making  , crucible performance,  alloy selection...making the iron from ore....melting/cooling practice...forging method...heat treating for max strength and appearance...polishing and etching..   I have done this long enough to have a little bit of experience in all the topics.  I am in no hurry but am anxious to get some good results. I have just bought a heat treating furnace and have figured out how to run my gas forge at a low  temperatures... Things are coming together...there was a guy  Dmytri who used to post here and told me ( a new comer ) it would take a long time before a person can make a good crucible steel....he was sooo correct...I shrugged it off as I had more attitude than skill.   

For me it is important the challenge is there and remains there. Weaving in what I learn about metallurgy with the historical accounts and what Verhoeven and some of the other modern experts are putting out there  is exiting.  The intelligence of those that came to this activity before us astonishes me.

 

[Alan Longmire]

Speaking of which, I recently found this article you may enjoy.

The_Cutting_Edge_Technology_Ferghana_Pro.pdf

courtesy of Acedemia.org.  Lots of interesting stuff in there from a relatively different (compared to Indian and Sri Lankan processes) central Asian location.

[Jan Ysselstein]

Thanks Alan......A very interesting article    .....C. Ritter von Schwartz once described a similar process ..I am guessing at the exact wording because I cannot find his quote. Steel was made

by adding magnetic sand, some laterite and a bit of charcoal into a crucible and heating  it.

 

To most of us familiar with iron and steel that description makes no sense....if the magnetic sand was not magnetite but granulated cast iron the statement would make complete sense and it would be very similar to the method suggested in the article. I have tied to search to see if the term magnetic sand may have been used to describe granulated cast iron. The closest I came was Iron Sand = Cast iron . I think it is quite possible C.R.von Schwartz did have it right and there was confusion of terms.

I have done an experiment along these lines and experienced a crucible failure late in the melt...to do this again I would fire the crucible for about 1 hr. before using it..this mix will attack an unfired crucible very quickly. 

[Jan Ysselstein]

While waiting for the technology I thought I would try to get some larger ingots in play. This crucible contains 1637 grams of metal and should result in about 1.5% carbon steel.. I have added a little lift to the round bottomed crucible so it will stand up without falling over. This crucible is very close to the central Asian crucible shape as shown by Alan  above. I will melt tomorrow and pull the crucible the next day. I am also experimenting with some larger crucibles having a lenticular shaped ingot.....these and the one shown here will go up to 2000 grams.   This crucible is not full.  Actually the crucible will hold about 4000 grams but I would have to add materials after the initial ingredients are molten ( we can do that ).

Now 2000 grams is 4.4 lbs.  and 4.4 lbs is 14.7 cubic inches of steel if our imaginary sword is .25 x 1.5 x ( X ) inches X would be 39 inches long ..plenty of metal at 2000 grams. Here I have assumed a lot of grinding to be done,  many of the historic swords weighed just over two lbs.

Edited October 5, 2019 by Jan Ysselstein