'Konasamudram' Process

[Jan Ysselstein]

"The last 3 ingots have huge cavities under their cold tops ..it seems the problem got worse over time.. Ingot #5 sgould be ignored and not even be in the picture."

There are two phenomena ( probably more...the cast iron is getting a little dirtier as the supply pile shrinks and the resulting carbide quantities seem to indicate the latter ingots are lower in carbon.

Jan

This would be a good time for some of you to post pics or links to pic of wootz that may have been made by the above process. That look is he goal for this thread.

I cannot forge them for a week at least.

Jan

Edited January 18, 2015 by Jan Ysselstein

[Jan Ysselstein]

Ingot #8 has been melted..due to a failing crucible wall, I had to pull out of the trial early ...I ran for one hour, rather than the planned 1.5 hrs. The top looks good, the side has some porosity but none looks deep. I did use glass but no glaze..to reduce bottom or side porosity I will use glass and glaze only at the bottom. The ingot weight is 1209 grams.

 

Glass was black with a thin green layer on the top. As my forge is my melting furnace I will finish all melting before turning the forge back to heating.

 

#9 is staged, #10 will be it for a while until the new batch of crucibles dries and gets fired, #10 will be a test of the glaze/glass combination using only homemade cast and homemade wrought. Assuming we are successful by the end of the thread ...I can see a need for cast iron stock and will shoot for that in future smelts.

Here is a rough pic.

 

Edit: #10 did not contain homemade wrought iron as planned.

Edited March 13, 2015 by Jan Ysselstein

[Jan Ysselstein]

Ingot#9 was melted last night, melting was done at a somewhat (guessing) lower temperature. The dents in the top probably indicate bubbles of gas between the glass and the molten metal. A 1200 gram ingot, glass , no glaze..both #8 and *9 had no remaining carbon on top of the glass layer when opened. Glass was green and dark color , the green top surface has some tiny bubbles imbedded. A bottom defect will require cutting the ingot and make this the first one to be forged.

 

Here are some pics, #10 is staged as a repeat of 8 and 9 ,, what was that statement about expecting different results from repeating the same steps? Crucible confidence building. Actually, it will be nice to see the degree of variability in the pattern of several ingots made about the same way.

 

Klaas, By using the same glass over and over ..do you see the viscosity rising or dropping?

 

 

Jan

Edited January 21, 2015 by Jan Ysselstein

[Jan Ysselstein]

KOS#10 has been melted , top looks good sides look rough as always.

 

Now I am done melting, will probe the forging for the next two weeks at the Paramecium Forge ( in spare time). This is my first foray into proper carbon level of the wootz range 1% to 1.9%, all previous experimentation was done with white cast iron.

 

 

Jan

Edited January 22, 2015 by Jan Ysselstein

[Klaas remmen]

Hi Jan

 

What do you mean with viscosity?

 

I never care too much about these holes on the side.. in my experience they do not indicate that an ingot is easy to forge or not.

 

so what are your conclusions? Less heat is better for your crucibles?

what about carbon on top of the layer? Works better for your crucibles?

How about re-using glass? not so agressive or the same?

[Klaas remmen]

Oh yes and Jan, what do you mean by glazing? doe you glaze the inside of your crucicbles.???

[Jan Ysselstein]

Klaas,

 

I try to glaze the outside of the crucibles to seal them. Glass was not recycled from run to run...if it works don't mess with it. Viscosity is fluidity I used a low melting frit 3110 , I would think as the glass picks up more iron it would get a lower melting point and become less viscous.

I did add a bit of carbon but never saw it..I think it helps ...

 

Less heat is always better for the crucibles but may not work well for the steel. At really high temps, some of my crucibles will soften. When we are talking heat, we are talking about 1300 C and above.

 

I have made 8, the last one looks good, but frankly, I am not sure why ( the glass helped but even some of the glass ones are not that great). The next series will be planned well..I really have to let some of this info sink in before reacting.

 

Jan

Edited January 22, 2015 by Jan Ysselstein

[Klaas remmen]

Hi Jan

 

OK. I still think that the weird grey ingot looks neat.

As I said, the one I forged was easy, it stayed easy till the end.

IF i'm not mistaken it was the ingot which made this bar:

 

 

Hi all

here is the bar I showed in post #91 again. It is forged a little further.
I took a monster at the same place I took the one where the metallographical pictures come from.
Take a look at the structures.... Seems like very very fine pearlite with a little bit of cementite, and a lot of very small graphite flakes to me. So the structure at that pont (end of the bar) went from a lot of cementite to graphite... I am not afraid that this structure is through the entire steel, because the pattern is still very visible on other places.

keep it up!

[Jan Ysselstein]

Klaas,

Thanks for posting that , I remember the discussion and thank you for the encouragement. I think some of the beginning knife makers should see some of this steel , it is just beautiful. Should I never get the ideal pattern I am reaching out for...I am totally blessed by the amount of information I have picked up. Many years ago Pendray gave a couple of talks at ABANA conferences..I did not have a clue what he was talking about..he kept hugging this big crucible ( about 1/2 gallon) and pointing to what was in it..the language was foreign to me ..I was just hoping to learn to forge weld at the time. Maybe someday I will get the chance to chat with him on this subject.

Jan

[Dan Bourlotos]

Generally the more glass modifiers you dissolve into an amorphous silica matrix, the lower the viscosity gets after Tg. This isn't always the case, and sometimes depends on the amount of modifier you add because some materials, like alumina, can be both a modifier AND a former.

In this case, the iron is the modifier, and to my knowledge, doesn't act as a glass former.

[Jan Ysselstein]

Thanks Dan,

 

I am concerned about the iron becoming an additional fluxing agent in the glass I am adding.

Jan

[Dan Bourlotos]

Totally late to this, but yes: The more iron you add, the lower the viscosity. It will act as a fluxing agent for the glass. I am not entirely sure why that might be a problem though.

[Jan Ysselstein]

Getting back to this topic, I will be forging ( testing for forgeability ) this week. I will try to test all the samples with potential , giving the highest priority to the larger ingots. Ingots 3, 8,9,10 are most likely to make a nice pattern.

 

Dan ,

The flux is not picky and will attack the crucible silica and weaken the crucible.

Jan

[Jan Ysselstein]

Mark,

 

To elaborate a bit on what I do prior to forging. I will be heating at about 1000 C ( or just below) for a few hours...then pull the hot cakes and let them cool on a firebrick in air. This is considered a fast cool...if I were to furnace cool I would start seeing lots of cementite in the grain boundaries. I will examine the cooled metal with a loupe to see if large cementite areas have redistributed....if they have, I heat again ( slowly) and after an hour or so above 900 C I begin to gently forge.

 

My final carbon concentration is all guess work and I may still be too high.

 

Jan

[Jan Ysselstein]

Today I soaked #1 and #3 for 3 hrs at 1050 C...I tested them by forging each a bit and encountered no problems ( probably 5-7 times in and out of the furnace). Tomorrow I will try 8 and 10 , hoping I do not mix them up. #9 is the most promising ingot.

Here are some pics of the improvised furnace sitting on top of my improvised crucible furnace which once was my welding forge.

 

 

Jan

 

I looked at the etched surface and am having a difficult time describing it, #3 has a fine grain with some cementite in the grain boundaries

#1 is not clear but may be very fine grained as well.

Jan

[Jan Ysselstein]

Ingots #8 and #10 seem to be forgeable as well , three hours at 1060 C. There is a very fine grain with very little cementite in the boundaries.....beautiful.

 

Jan

Edited February 21, 2015 by Jan Ysselstein

[Jan Ysselstein]

I think the wootz types need to see some non imaginary grain boudaries, this is ingot #10. I would not get too enthusiastic interpreting this image, it is crude, dirty and is still much in the decarb layer. I suspect the initial dendritic structure is still partially evident here...so much linear alignment here.

Edited February 23, 2015 by Jan Ysselstein

[Jan Ysselstein]

I will be grinding the surface of all the ingots and removing the hard corners...to prevents cracks from growing into the forging. There is still a good chance some of these will break ( #2 is a bust from the start ). Looking at the material through a loupe, tells me I need to change the formula to 1.6% carbon from 1.8% carbon. I will do that on the next set. I hope to have some 1/2" thick bars by next week end.

 

Jan

 

Each ground ingot will be slowly brought up to the soak temperature in the little gas forge...held for an hour min. and forged. A charcoal/coke forge ( Murray Carter forge ) will be used to finish the forging down to 1/2" in thickness.

Now two points in the process provide important information to the maker, the ingot and the bar.

 

Jan

Edited February 23, 2015 by Jan Ysselstein

[Jan Ysselstein]

Ingot #1 and part of #3 are forged and will be looked at in the morning. #3 has a large hidden gas pocket which ballooned out during forging. I will be looking for large bits of cementite never dissolved during forging and soaking. The forging was done using the little heat treating cube as the heat source.

 

I attempted to make some cast iron this morning with the last of the pine charcoal..I need lots of cast iron to break up as an ingredient...each crucible sample should roughly represent the average carbon content of the supply. Several not so special blooms are begging to be converted to cast iron..I will give it a try.

 

Jan

Edited February 24, 2015 by Jan Ysselstein

[DaveEvans]

A truly fascinating thread. I admire your perseverance and the amount of time and effort and money you are investing. I now have a better understanding of the cost of this steel

Anxious [my normal state] to see the forged steel and a finished product.

Thank you for taking the extra time to share this process

[Jan Ysselstein]

Dave,

 

Thank you, it is a lot of work ...and as my wife keeps pointing out to me...a lot of expense. It is absolutely worth it. I was just sitting here looking at the pics of the first forging....,a rough grind and an etch. If I grind too much, I will get a good look at the structure but lose a lot of material in the process. There is sooooo much decarbed material to see it is easy to assume it is part of the structure. I have a good feel for what is going on..I think I am just at the upper level for carbon.( at 1050 C). Here is a pic showing the very first development of bands at the expense of the grain boundary cementite...this is the surface area of what will become a blade so the spacing is off but the width of these bands will grow.

Jan

Edited February 28, 2015 by Jan Ysselstein

[Jan Ysselstein]

That was bar #1 here is a pic of bar #3 showing what I hope is carbon on the move. The surface area of this bar will be increased by about 3x the current surface area.

Now is the time at which I have to decide in which directions to grow that area.

 

[Klaas remmen]

Hi Jan

 

Looks very promising. I can't wait to see what this will become!

 

keep it up!!

 

Klaas

[Jan Ysselstein]

Klaas,

 

Thanks for your enthusiasm. It seems this process will take a bit longer than I thought..I have been making charcoal and cast iron the last few days. Not having much luck..I call the making of partially reduced iron ore, deferred gratification, because it is unspectacular and looks just like the ore. Lately I have been getting deferred gratification squared--not good. Back to basics.

 

I cannot seem to play Niko's movie on my computer..tried downloading a special app and cannot make it work ( I will try again tomorrow).

 

It is amazing how eager the carbon is to go to the pattern..there are some large bits of cementite in places of bar#1 which did not dissolve during the soak/forging....so they will cause large cementite particles to overlay the more diffuse pattern of smaller cementite ( usually they coincide but not always ). They may yet dissolve during the remainder of the forging process.

 

The materials are here to improvise a light diffuser for photographing the steel ..I do not want to put pictures here that do not truly show the character of the steel ( maybe the beauty, should I get lucky). I like the way the blades are photographed here ( I like the blades as well ), this is what I will attempt to use for comparing the blades.

 

 

Jan

 

 

 

 

[Jan Ysselstein]

Ingot #1 and ingot#3 were forged ( heated with charcoal) to just under 1/4" ( second forging)

..ingot1 seems fine but #3 has some cracking at the center of the bar ( due to forging too fast, at a fairly high temperature..). We should still get a pattern sample from #3.

 

Ingots #2 and #9 had their roasting period completed and were tested for forgeability ( both look good ).

Ingots #8 and #10 are waiting to be forged.

Ingot #6 will be roasted and tested for forgeability tomorrow..it is a defective and small ingot it will be forged into a flat disc only.

Tomorrow I will clean #1and #3 and forge a little more to final thickness and have a look.....the forging speed is way ahead of the pattern development process. I am seeing quite a bit of decarb and need to come up with a method of controlling that. I should have some pics tomorrow.

 

Decarb is the biggest concern right now. I will be weighing my bars during the grinding process to measure how much I am losing , may be it is not as much as it seems.

Jan

Edited March 1, 2015 by Jan Ysselstein