Just really great! I remember when I was a teenager and trying to make a hamon on a blade; I sprinkled charcoal powder all over it before covering it with clay. When it came out, the carbon had absorbed a bit into the surface and it looked like raindrops all over the surface. Perhaps I had inadvertently done a shallow cementation process to the piece. Thanks for your video!
Thanks! The raindrops were certainly carburization. That's very similar to many old school case hardening processes. One thing to watch out for is that any fast case hardening process is going to be shallow. So, you'd have to be careful, or you can grind right through it.
Hi, could you explain better how did you calculate time to do cementation? Because at minute 2:49 you show a bar with 3/16 thickness x 1"x 36" but at min 4:09 you do calculation for a bar with 1/8" (2 faces)... Thank you!
We ended up preparing more parent material than we actually used. We only used the 1/8 material in the cementation process. The speed of carbon migration is dependent on temperature. There are charts available, but there is no good way for a blacksmith to determine on his own- short of recording your times and temperatures, then breaking your test piece in half to see how far the carbons migrated through.
Each bar (6 bars total) was 12 inches long by 1 inch wide by 1/8 inch thick. The only important measurement is the smallest one. Carbon will migrate through steel from every dimension, but obviously will complete its journey from the smallest dimension fastest. That will determine when the carburization is completed.
@@LynneFairchild Thank you a lot your coments and very usefull help. My question was in the way to try to guess how to calculate time not to a bar but to a rod. But once with a rod the smallest size will be diameter, i guess calculation of time shoud start from here (diameter), am i correct? Good job and very useful the video you posted. Thank's again.
Hey there, I'm interested in Balcksmithing Forging, Smelting and Iron/Steel making and I had a question about this process. I've been looking into steel making online and it seems the most efficient way is to make pig iron from raw iron ore and charcoal in a blast furnace then decarbourise a lump of pig iron into steel. However when i try and look into the methods used to create steel they all seem to mention making wrought iron and then shipping it off to be REcarbourised through this process. Without using large industrial Bessemer containers is there a way to efficiently convert Pig Iron into Steel without going too far and making wrought iron?
I think you may have your terms flipped. Allow me to clarify. The way medieval smiths made steel was to start with iron, and carburize. Before the process I demonstrated, the typical method was to do a simple shallow case hardening, and perhaps to take a case hardened bar and fold it so the hard skin was folded into the center of the iron. The process of cementation was a refinement of that, and cut off the extra labor of kneading the carbon into the steel. The way we make steel now is to make cast iron (often called pig iron at this stage, but that is not a precise term) which has perhaps four times the amount of carbon you would want for steel, and blast air through the molten iron. The oxygen will bond to the free carbon in solution, and come out the other side as a mixture of carbon dioxide and carbon monoxide. By regulating the amount of air blasted through the cast iron, you can regulate the carbon content in the resultant steel. This is the Bessemer process, and this is a Decarburization process. It is absolutely possible to pull all the carbon out, and some manufacturers did that on purpose. It's impossible to do the Bessemer process without a Bessemer furnace, but it is indeed possible to bake the carbon out of cast iron. If I were going to try, I think I would slice the cast iron into thin cross sections, and either cover them in pure iron powder or sandwich them between pieces of mild steel, and let the carbon migration process run the other direction. This would be very energy inefficient, but it could be a neat exercise.
What we call mild steel is really just iron. It's called steel because it's made with the Bessemer process (actually, the oxygen converter process, which is a refinement of the basic Bessemer process), in which O2 is blasted through molten cast iron to bond with most of the loose carbon and create carbon dioxide and steel; but in the case of "mild steel" (ie: iron) virtually all of the lose carbon is bonded and what's left over is... basically iron. But since the product is a monometal (made from a poured ingot with a contiguous internal crystalline structure) and not assembled from layers, it was structurally different enough from "iron" (ie: wrought iron, made in a bloomery furnace) that it took a different name. For the purpose of cementation and making steel from iron, it's an excellent starting material.
@@LynneFairchildI'd like to offer a minor correction/clarification. The reason mild steel was called "steel" and not iron was indeed because Bessemer was trying to produce tool-grade steel. As the industrial revolution kicked off, however, the term mild steel lingered to meaningfully differentiate it from wrought iron. Wrought iron had many slag inclusions that rendered it unserviceable for modern machine applifwtions. Eg, if you can get your hands on some, try machining wrought iron. Everything cuts as smooth as butter till you hit a slag inclusion. Those really tear up your bits. Therefore, mild steel was increasingly used for stronger and lighter gun barrels that could be more easily bored (with crucible cast steel bits). It was also less likely to suffer catastrophic failure of the breach.
What questions do you have for my husband related to blacksmithing?
Great commentary and demonstration, very well explained. You got yourself a new subscriber.
Thanks! More of my blacksmith husband's videos can be found on his RUclips channel (recently made) at: www.youtube.com/@VonGlierBlacksmithing
Just really great! I remember when I was a teenager and trying to make a hamon on a blade; I sprinkled charcoal powder all over it before covering it with clay. When it came out, the carbon had absorbed a bit into the surface and it looked like raindrops all over the surface. Perhaps I had inadvertently done a shallow cementation process to the piece. Thanks for your video!
Thanks! The raindrops were certainly carburization. That's very similar to many old school case hardening processes. One thing to watch out for is that any fast case hardening process is going to be shallow. So, you'd have to be careful, or you can grind right through it.
Well explained!
On his behalf, thanks!
Hi, could you explain better how did you calculate time to do cementation? Because at minute 2:49 you show a bar with 3/16 thickness x 1"x 36" but at min 4:09 you do calculation for a bar with 1/8" (2 faces)... Thank you!
We ended up preparing more parent material than we actually used. We only used the 1/8 material in the cementation process. The speed of carbon migration is dependent on temperature. There are charts available, but there is no good way for a blacksmith to determine on his own- short of recording your times and temperatures, then breaking your test piece in half to see how far the carbons migrated through.
How many bars did you put inside canister? And what is the size of each bar? (lengh x thickness x width) aprox? Thank you
Each bar (6 bars total) was 12 inches long by 1 inch wide by 1/8 inch thick. The only important measurement is the smallest one. Carbon will migrate through steel from every dimension, but obviously will complete its journey from the smallest dimension fastest. That will determine when the carburization is completed.
@@LynneFairchild Thank you a lot your coments and very usefull help. My question was in the way to try to guess how to calculate time not to a bar but to a rod. But once with a rod the smallest size will be diameter, i guess calculation of time shoud start from here (diameter), am i correct? Good job and very useful the video you posted. Thank's again.
You're welcome! Glad that the video was helpful.
Hey there, I'm interested in Balcksmithing Forging, Smelting and Iron/Steel making and I had a question about this process.
I've been looking into steel making online and it seems the most efficient way is to make pig iron from raw iron ore and charcoal in a blast furnace then decarbourise a lump of pig iron into steel. However when i try and look into the methods used to create steel they all seem to mention making wrought iron and then shipping it off to be REcarbourised through this process. Without using large industrial Bessemer containers is there a way to efficiently convert Pig Iron into Steel without going too far and making wrought iron?
I think you may have your terms flipped. Allow me to clarify.
The way medieval smiths made steel was to start with iron, and carburize. Before the process I demonstrated, the typical method was to do a simple shallow case hardening, and perhaps to take a case hardened bar and fold it so the hard skin was folded into the center of the iron. The process of cementation was a refinement of that, and cut off the extra labor of kneading the carbon into the steel.
The way we make steel now is to make cast iron (often called pig iron at this stage, but that is not a precise term) which has perhaps four times the amount of carbon you would want for steel, and blast air through the molten iron. The oxygen will bond to the free carbon in solution, and come out the other side as a mixture of carbon dioxide and carbon monoxide. By regulating the amount of air blasted through the cast iron, you can regulate the carbon content in the resultant steel. This is the Bessemer process, and this is a Decarburization process. It is absolutely possible to pull all the carbon out, and some manufacturers did that on purpose.
It's impossible to do the Bessemer process without a Bessemer furnace, but it is indeed possible to bake the carbon out of cast iron. If I were going to try, I think I would slice the cast iron into thin cross sections, and either cover them in pure iron powder or sandwich them between pieces of mild steel, and let the carbon migration process run the other direction. This would be very energy inefficient, but it could be a neat exercise.
@@LynneFairchild Thank you very much! I'll keep that in mind for a future experiment!
@@commanderpuffy1014 Happy to help!
I usually wrap the screen into a tight triangle to minimize mess and max siphoning
I'll tell my husband.
My husband said, "Smart!"
Hey, man. Coke (as it burnt out coal) makes a great substitute for Graphite. Much better than charcoal.
My husband says thanks.
I was confused. He turned steel bars into hi carbon steel? Where’s the iron?
What we call mild steel is really just iron.
It's called steel because it's made with the Bessemer process (actually, the oxygen converter process, which is a refinement of the basic Bessemer process), in which O2 is blasted through molten cast iron to bond with most of the loose carbon and create carbon dioxide and steel; but in the case of "mild steel" (ie: iron) virtually all of the lose carbon is bonded and what's left over is... basically iron. But since the product is a monometal (made from a poured ingot with a contiguous internal crystalline structure) and not assembled from layers, it was structurally different enough from "iron" (ie: wrought iron, made in a bloomery furnace) that it took a different name.
For the purpose of cementation and making steel from iron, it's an excellent starting material.
@@LynneFairchild
Thank you so much! Thanks for taking the time to explain 😊
You're welcome! Hope it helped!
@@LynneFairchildI'd like to offer a minor correction/clarification. The reason mild steel was called "steel" and not iron was indeed because Bessemer was trying to produce tool-grade steel. As the industrial revolution kicked off, however, the term mild steel lingered to meaningfully differentiate it from wrought iron. Wrought iron had many slag inclusions that rendered it unserviceable for modern machine applifwtions. Eg, if you can get your hands on some, try machining wrought iron. Everything cuts as smooth as butter till you hit a slag inclusion. Those really tear up your bits. Therefore, mild steel was increasingly used for stronger and lighter gun barrels that could be more easily bored (with crucible cast steel bits). It was also less likely to suffer catastrophic failure of the breach.
I'll pass this on to my husband.
Well explained!
On behalf of my husband, thanks!