My initial journey into crucible steels.

[Daniel Cauble]

First run I have ever done making crucible steel. Firstly I want to add that I am very adept in the hearth refining process, or orishigane. At this point I pretty much make material between 1.3-1.8%C out of anything from bloom iron to crane cable. Well I have been doing a lot of studying in the realms of breaking this orishigane cold to get an inspection of the grain, and see if any colors pop out. Typically this causes many pieces to break off, smaller than I typically feel like dealing with. Having a surplus of this jewel steel, and I decided to breathe a new life in these collected piece by melting them in a crucible. These pieces range from 1.3-1.7%C for the most part. I didnt throw in anything over 2% C. A spark shows the average piece going in, which is a steel and spark devoid of Mn.

The following is what I make from the hearth that I used for this in the hearth refining/orishigane process, and then the first puck made and forged. Prior to knowing a whole lot.
 

 

[Daniel Cauble]

The forging temps were a little iffy on this bar. It is a struggle to know the temp windows when you are guessing carbon.

[Daniel Cauble]

At 60x or 100x mag etched with ferric.

[Daniel Cauble]

2nd puck I made the mistake of attempting an Al kill too late as it was too cool. It was made, pulled, inspected and then remelted with a little more feed material.

[Daniel Cauble]

This be my 3rd puck on its 2nd melt. Gaining more carbon every remelt. This I accidently went a little sparing on the Al for the kill, which resulted in some tiny pockets of trapped gas, or inclusion. Instead of wasting gas, as soon as I found this I decided to remelt it with yet more material. This time using some of my orishigane that went 2% as additive as I felt the carbon on this was lower than the 1st puck I made for some reason. This reply only contains pics of this 3rd puck fyi. Something to note I read later on that the pucks can turn a bronze color once they go cast....this one did that, but the grain still looked like steel.

[Daniel Cauble]

4th puck, 3rd melt on mostly same material. Looked great. My errors during the melting phase were in check. Much experience gained.

I worked this in the 1900F range, assuming C% was around 1.9%. Which I was wrong, and didnt realize until the bar was well on its way. In conversations with Jokke and Timothy (Both including Josh and Jeff Pringle also) while both have been mentoring me a bit through the whole process, we realized my carbon may be a bit higher. This range did not dissolve the cementite.

[Daniel Cauble]

This gave us an idea to cut from the bar samples, and allow them to heat up for just over 2min at specific temps, 50F (Even though I was told 50C, I incorrectly read) apart starting at 2000F, and did 3 samples with 1 control, and then an extra for whatever. So 1 at 2000F, another at 2050F and another at 2100F, and then quenched each in Parks 50 to make sure they just dont simply migrate back out during a slow cool down. I even etched them together at the same time, in ferric (I need me some Nitric).

[Daniel Cauble]

Unfortunately the one at 2100F didnt show signs of full dissolving, and we concluded that this bar was over 2%C.

I have thought about slowly forging it at around 2200F, and I still might, but if it fails, I will simply use this as material to beef up C% in further runs as I know its around 2%. Further temp tests can help pin that down.

[Jan Ysselstein]

Daniel, You are on a fast track..it looks like an interesting project...you have some good support there , what would we do without Al.

[Alan Longmire]

Good to see you posting here again!  And it looks like you're on your way to some interesting stuff.  

[Daniel Cauble]

Thanks borh of you.

 

Most of my interactions the past few years have been going on, on Facebook, and many of the groups and my own inner circle. Its a shame however due to the fact that conversations that are rich with information are not easily catalogued and accessible even for myself.

 

Makes me want to make an app for facebook for just that. The search functions for keywords is mostly non-existent and google doesnt really track facebook, so its all a struggle.

[Jan Ysselstein]

Sometimes I link the two places by mentioning the other location in a post.

[Daniel Cauble]

I want to make mention that forging this bar of cast ag ~1900F was almost as bad as movong cold mild steel. Lol.

[Tim Mitchell]

Good to see you posting your efforts here Daniel.  You are doing a great job and definitely on a fast track.

I am curious about your carbon content still.  As far as I remember, you didn't add any graphite or other carbon to your melt, is that correct? 

The carbon content is definitely up at least 2.2% from looking at the phase diagram... but unless you let it sit in the crucible for an age at melting temperature, the carbon has to be from your steel.  Is it possible that you miscalculated the carbon content of your steel from your spark tests?  The clay graphite crucibles can add a few points if you leave the melt at temperature for a long time, but I would be incredibly surprised to see that jump in carbon content coming from the crucibles... Just a thought...

[Daniel Cauble]

Actually i purposely added at least 200-300g of material that was atleaat 2% to the crucible steel that was a bronze color. It is difficult if not impossible to tell carbon by spark testing crucible steel, so what i assumed was lower than my first run may have been wrong and i didnt need to raise thr carbon content.

 

I estimate carbon of my orishigane based kn spark, but also due to the numerous runs at particular furnace settings i create steel at the very edge of cast, and sometime it goes full cast, or sometimes i get steel that is a gradient of steel and cast, so it gives me a good indication of where i am at.

 

The material i added in was deff. In the above 2% range. Its grain was gray and tbr sparks were very short. Also, since my furnace settings were in a zone where it could be either in the end, the cast i added could easily swing between 1.9-2.2%C

Edited December 14, 2017 by Daniel Cauble

[Tim Mitchell]

Ok, that makes sense now.  It is amazing how little carbon it takes to make a big difference.  When we think about it, the 0.5% difference of carbon is a tiny part (10g) of the final say 2 kilo ingot.

I am lousy at spark testing, I just haven't had enough need to educate myself... I use materials with known amounts of carbon, it helps with getting my ingots consistent. But you have some good metal there, it is worth watering it down to get some really good ingots. 

What do you think your phosphorous level is in the ingots?  Looking at the density of the dendritic pattern of the bar, I am guessing that you have a bit in there, there is plenty of white there.  It may be the high carbon too, but I wouldn't be surprised if you have a healthy level of Phosphorous there too.  

[Daniel Cauble]

I am etching in ferric chloride, from what ive read and been told is really the wrong etchant if that makes a difference.

 

The hearth process tends to lower phosphorous levels in steel, and if i remember right, the feed steel for the orishigane would have been a low phosphor and sulfur level. I could be wrong though. I have made so much hearth steel from various iron sources that i sometimes get it mixed up.

 

Also, is there any merrit to the bronzed ingot?

Edited December 14, 2017 by Daniel Cauble

[Daniel Cauble]

Of course we are talking about lowering P levels in bloomery. If some of this orishigane was from melted crane cable, the steel could have maybe taken up some P from the charcoal ash itself.

 

If i could get an educational grant and be able to send troves of samples off to get tested, a lot of understanding would be made in all processes.

 

I want to do some write ups.

[Daniel Cauble]

Im also looking into an inverted metallurgical scope.

[Kreg Whitehead]

That is some kewl lookin stuff. I gotta ask....it that the only advantage...or are you shooting to make a superior steel than you can buy??

You mentioned 2 percent carbon a time or tow. I am curious as to how that compares to say 52100

Couldnt help but notice the glass......is that how you are adding/upping the carbon content?

Sorry if these are dumb question. Curiosity got the best of me here =)

[Daniel Cauble]

I make orishigane because i am both obsessive over mastering the process, and because i do not have access to tamahagane. Plenty of bloomery, but nothing lile tamahagane. My orishigane iz the closest thing on earth, and itnis the reason why Japanese sword smiths allow up to 20% orishigane to be mixed in with their tamahagane. My need for my orishigane is coupled with my desire to mimic the work and product of a japanese sword smith. I am also interested in using my steel in my kitchen cutlery.

 

Beyond that and the reason for this thread was to properly recycle my small bits into crucible steel, all the while learning crucible steel in the process. The challenge is more intruiging than carving out a chef knife out of a bar of 52100. Which is also why i almost exclusively make kitchen cutlery using sanmai construction with mild or straight iron jackets.

 

I also have a theory that man typically achieved things through simplification, and to successfully make a water patterned crucible blade out of one type of material could lead credence to my postulation.

[Jerrod Miller]

37 minutes ago, Kreg said:

That is some kewl lookin stuff. I gotta ask....it that the only advantage...or are you shooting to make a superior steel than you can buy??

You mentioned 2 percent carbon a time or tow. I am curious as to how that compares to say 52100

Couldnt help but notice the glass......is that how you are adding/upping the carbon content?

Sorry if these are dumb question. Curiosity got the best of me here =)

Not to step on Daniel's toes or anything here, but...

This is all done for non-performance reasons.  Typically it is for a combination aesthetic and historical replication (cool factor, spirit, whatever you want to call it).  Of course, getting a good quality material is also very important, hence all the effort to refine the process to get repeatable results with the desired aesthetic and physical properties.  For best physical performance, you cannot beat a modern mono-steel.  

52100 has about 1%C, so 2% is about double that, but it isn't going to have the Cr that 52100 has.  More carbon will affect how the material is worked and heat treated.  Higher carbon levels generally produce more carbides, which is what is causing the aesthetic for these materials.  There are also other things going on with retained austenite, dissolved carbon, and other structures (pearlite, martensite, etc.).  

The glass doesn't have C in it (to any meaningful extent, at least).  It is added to form a slag layer over the steel in the crucible.  Serving kind of as a flux.  

[Kreg Whitehead]

1 minute ago, Jerrod Miller said:

Not to step on Daniel's toes or anything here, but...

This is all done for non-performance reasons.  Typically it is for a combination aesthetic and historical replication (cool factor, spirit, whatever you want to call it).  Of course, getting a good quality material is also very important, hence all the effort to refine the process to get repeatable results with the desired aesthetic and physical properties.  For best physical performance, you cannot beat a modern mono-steel.  

52100 has about 1%C, so 2% is about double that, but it isn't going to have the Cr that 52100 has.  More carbon will affect how the material is worked and heat treated.  Higher carbon levels generally produce more carbides, which is what is causing the aesthetic for these materials.  There are also other things going on with retained austenite, dissolved carbon, and other structures (pearlite, martensite, etc.).  

The glass doesn't have C in it (to any meaningful extent, at least).  It is added to form a slag layer over the steel in the crucible.  Serving kind of as a flux.  

Thanks....I heard/learned on here that 1084 has 84 points of carbon...52100 100 ect. I wondered if that was the same as 1%

It gorgeous stuff for sure.

[Joshua States]

Daniel, I do not have any idea how I missed this, but I have been reading and rereading this thread today. Thanks for the great photo record and explanations. I am anxiously awaiting more progress.

[Daniel Cauble]

Seems people missed my orishigane thread too.