Carburizing 1018 steel, experiment idea.

[running bird]

I always thought making your own steel was something fun and always wanted to try it. I don't have the equipment I would need, but its still interesting to think about to me. I tried to think up the easiest way to go about doing it and came up with what I think is a solid idea, but I need some opinions.

What I was thinking was that if you took some 1/16" 1018 (cant seem to find any retailers that sell 1018 sheet) it would make this kinda do-able. I would have considered other mild steels like A36 because they are sold in thinner sheet. But that .2% copper alloy does not seem desirable for later steps like forge welding. Some data sheets I found on 1018 say that carburizing penetrates about .06-.07". 1/16th" being .0625" would put it around the minimum depth that the carbon would diffuse into the steel. These data sheet also say that to carburize 1018 you have to hold between 1,600F and 1,700F for 8hr. This of course would require a HT kiln which I don't have yet. When I do get enough money to buy one this is definitely going to be one of the first things on my list to do.

Of course the amount of carbon that enters the steel would be hard to measure and probably would not be very high. So it seems like a smart idea to carburize small sections of the bar and forge weld them, draw out to 1/16", and repeat. The hardest part of this would be drawing out the bar to 1/16" (maybe this would be possible with a press? Could be possible by hand if you really pay attention to what you are doing and forge very even). The forge welding would also help evenly distribute the carbon. Maybe doing this 3 or 4 times would put a decent about of carbon into the steel. Add in a fast quench and maybe this would make the steel hard enough to be used?

This is all just an idea, by no means would this steel be superior to any mass produced steels. The carbon content would be questionable, unless you decide to send it off to be tested. but it would still be interesting to try it out one day and try and make the best steel I could without going too overboard. Maybe give it a few tries and compare results with different amounts of carbon and turn it into an experiment. It would be cool if you ended up with a very high carbon steel, say maybe 1.5% or something.

What do you all think of this process?
does it seem too time consuming? (I tried to think of the easiest way of going about this, but I'm not the smartest person around)
Do you think it would give decent enough results?
Anyone else try something like this before?


Kevin

 

[kuraki]

It's just too labor intensive for results that are likely lower quality than inexpensive high carbon steel. I'm all for experimenting, or playing around, so won't dissuade you from trying this, but you're unlikely to get any input from anyone along the way because of how low value it is in terms of labor vs reward.

At the end, you have, at best, pattern welded carbon steel. At worst, poorly welded low carbon steel. That you couldn't even take much personal satisfaction in saying you "made the steel" because you started with steel.

If you would like to experiment in making your own steel, I would suggest instead learning how to make your own crucible steel, which done appropriately will not only give you that personal accomplishment, but also have a higher chance of producing something desirable, like wootz.

 

[daizee]

Agreed.
I find this intellectually interesting, but with 1084 at $4/ft... what's your labor worth?

 

[running bird]

Thanks for pointing that out. I didn't really consider exactly home much time it would take me to do all this. If I ever do get around to it I'll try and see if I can bring down the time it takes a bit. If i cant reduce the time then I could always keep it as a side project and work on it here and there. Again its all just an idea.

I wouldn't be doing this to replace any production steels, I could easily buy most steels. This would be more for entertainment. Every now and then I try out a knife project that I focus only on entertainment, as a relaxed kind of practice. For example finding some scarps or severely worn out/damaged tools and forging it into a blade. But I usually don't spend much time on them, and as was pointed out this idea could be very time consuming.

I'm going to try looking into Wootz a bit more, I've heard about it every now and then and it does seem really interesting. I always wanted to get into casting bronze too so maybe I should start looking into casting equipment and start reading.

 

[SirSpice]

Clickspring has a fascinating video about carburizing mild steel using techniques that could have been used by the ancient Greeks:

 

[lanternnate]

There's a guy on YouTube who does some of this for novelty sake where he carburizes some piece of low carbon reclaimed metal in order to make a knife out of it. Looks up Green Beetle on YouTube if you want to see some of his stuff. His videos are goofy but can be entertaining. In one video he cast bacon into resin for handle scales, so practicality isn't high on his list

 

[JMJones]

I have messed with blister steel and sheer steel a few times for novelty with mixed results. Rich Furrer seems to have the process down but to my knowledge he has not shared the exact times and temps, however I have not looked into it for several years.

 

[jdm61]

Clickspring has a fascinating video about carburizing mild steel using techniques that could have been used by the ancient Greeks:

I wonder what the carbon content was in the various test rods?

 

[Salem Straub]

This would be a good subject for discussion over at Bladesmith's Forum. It's a more scholarly place for archaic techniques. Check out the "Bloomers and Buttons" section, and threads about Aristotle furnaces. You can pretty effectively carburize mild steel or wrought iron in them.
I definitely wouldn't use A36, that stuff is too inconsistent. 1018 is not that expensive, might as well set yourself up for a better likelihood of success.

 

[jdm61]

This would be a good subject for discussion over at Bladesmith's Forum. It's a more scholarly place for archaic techniques. Check out the "Bloomers and Buttons" section, and threads about Aristotle furnaces. You can pretty effectively carburize mild steel or wrought iron in them.
I definitely wouldn't use A36, that stuff is too inconsistent. 1018 is not that expensive, might as well set yourself up for a better likelihood of success.

A number of years ago, someone, perhaps Ed Caffrey, said that A36 is code for "any combination of 36 different types of scrap steel."

 

[running bird]

There's a guy on YouTube who does some of this for novelty sake where he carburizes some piece of low carbon reclaimed metal in order to make a knife out of it. Looks up Green Beetle on YouTube if you want to see some of his stuff. His videos are goofy but can be entertaining. In one video he cast bacon into resin for handle scales, so practicality isn't high on his list

Thanks for the recommendation. I have been watching him a little but and his video on the "american knife" helped me come up with the idea. I believe he used .999 iron flat bars though, I get why he did but I would have used 1018. The extra alloying elements that come in 1018 like manganese would help you get more out of the steel especially when working with a steel that would have a unknown, but high carbon content.

For consistency would it be smart to add a carbon source by weight in comparison to the steel? For example something like 8 oz of carbon for every pound of steel, and be sure to use the exact same temperature and times for each batch. I would assume that this would help out with the consistency by giving the carbon the same opportunities/environment to enter the steel. But how consistent is carburization? I didn't pay much attention in chemistry when I was in high school, so I don't really remember how science works hahaha.

Does anyone know who or where to send steels to to have the continence tested? Id imagine there are a lot of labs that do these kinds of tests but I'm not aware of any or how much it costs

 

[lonepine]

Isn't this the same as "case hardening", where you get all the pretty colors on the metal's surface? I don't know if it would make a good knife or not, but it could be pretty. ;-)
- Paul Meske

 

[kuraki]

Color case hardening is a bit different. A version of it can be done by using something like Kasenit and then blueing the surface. But you don't want the even affect of atmospheric carburizing if you want a color case, as it's the variation in the absorption of elements that gives the different colors. And it requires more than just carbon.

 

[running bird]

Isn't this the same as "case hardening", where you get all the pretty colors on the metal's surface? I don't know if it would make a good knife or not, but it could be pretty. ;-)
- Paul Meske

Case hardening is a much different process. There are a few different kinds of case hardening. I'm not an expert on it but there is a channel on YouTube about different gunsmithing tequniques (I will link the video or channel for you if I can find it again). In one of the videos they used a mixture of chicken bone and ash to case harden some steel. They put it all in a container. Then heated it to around 1,600F for a few hours, then dropped the steel into a barrel of brine.

I'm asumming all the different chemicals from the organic material used gives it the beautiful colors. But the carbon does not penetrate deep into the steel and only hardens a thin outer layer. Almost like a thin layer of glass on the steel.

In the process I'm describing you would be letting a pure carbon source be absorbed deep into the mild steel. Then through forging, foolding, and more carburizing processes evenly distribute the carbon.

(Video I referred to)

 

[Salem Straub]

What you are describing could be interpreted as an original form of case hardening... just putting low carbon material in a case, with carbon-rich material surrounding, and holding at heat to allow carbon to diffuse into the surface. Blister bars were made this way, and then sheared, piled and welded one or more times to make simple steels...
For carbon to penetrate into the material to a significant depth relative to its thickness, it has to be pretty thin stock... or small pieces falling through burning fuel or surrounded by it, as in tatara and oroshigane processes. Carbon diffusion is a slow process, it works well though if you carburize thin layers and pile them. That's essentially what happens when making a bar of damascus steel anyway; if one of the steels used is low or medium carbon, by the time a hundred or two layers is reached, carbon content will have homogenized throughout the bar, as the layers are so thin.