Melting Down Old Steel

So, sorry if this is an old topic. Today, like most days, I was cruising the bay and I am just always struck by old sheffield steel that is no longer any good - like WAY beyond restoring, you know, wall of shame stuff.

Has anyone ever melted that steel down and re-made razors using it? If this just too much work and not worth it? I have ZERO metallurgical experience and even less capacity - just curious! Even if it wasn't for a new razor. For instance, I think I would buy a cool ring melted down and made from some sweet old sheffield steel, especially if it was stamped you know? Am I crazy!?!?!:shrug:

There is zero point to it.

Off the top of my head:

- There are many different types of Sheffield steel. You'd be mixing many unknowns.
- It's also time consuming.
- It's freakin' dangerous. Seriously, molten steel can kill you. There are many things that are not obvious but can have catastrophic effects.
- It's cost prohibitive. Good quality tool steel is less expensive than just the fuel you need to melt the same amount of steel.

I have plans to do a melt someday, but it's not something I treat lightly.
Carelessness about temperature gradients can make things explode, and molten steel is not something you want flying around near you. With careful planning you can of course do it, and do it safely. But it's not something to jump into without careful preparation.

Did you just talk yourself into it!? Zero point, or you are going to do it some day?

IIRC, in reading about this topic in the past, the temperature to melt it to a molten state is considerable. Maybe beyond the resources of the average hobbyist ? Not sure ........ :shrug:

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Originally Posted by Bruno

There is zero point to it.

Off the top of my head:

- There are many different types of Sheffield steel. You'd be mixing many unknowns.
- It's also time consuming.
- It's freakin' dangerous. Seriously, molten steel can kill you. There are many things that are not obvious but can have catastrophic effects.
- It's cost prohibitive. Good quality tool steel is less expensive than just the fuel you need to melt the same amount of steel.

I have plans to do a melt someday, but it's not something I treat lightly.
Carelessness about temperature gradients can make things explode, and molten steel is not something you want flying around near you. With careful planning you can of course do it, and do it safely. But it's not something to jump into without careful preparation.

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You know what they say:
:brunoisright:

While melt is unrealistic, what about forge welding the pieces together and then just hammering them into whatever new shape you want?

Now, where the Bruno (to this date) fears to tread, there are a few of us who would and could dare such things. Bruno's cautions about the dangers are worthy of consideration, as are his correct assertion that it's simply cheaper to start with new good enough steel bars. With the right equipment, to achieve the right temperatures (steel melts at a lower temperature than iron) and controls over the process, it can be done with only smallish sorts of risks to the operators.

I'd start mailing all your broken bits to Bruno. Once his wife gets tired of walking around the growing scrap pile he will be forced to do his melt.

I'm not sure about the different types of Sheffield steels. Once upon a time, Josh and I looked at spectrographs of the steels in a hundred or so dead razors from several Swedish, German, Italian, French and UK manufacturers. What was very interesting was that the chemistry was nearly identical across all those manufacturers and with no statistical difference between them and the old Sheffield blades tested. I would argue that Sheffield steels for razors were very consistent and highly prized by multiple manufacturers.

Magpie: As to forge welding a bunch of broken pieces: some material will be lost to the process, but a lot of other steel scraps have been forge welded into billets for years longer than the metal recycling yards have been in business. Laying up the broken pieces to minimize the gaps and not having to do much spot welding to hold the mass together would be the way to get it done. Some fellows would wrap the mass of old razors in used heat treatment foil, then the wrapped bunch into a mild steel tube and weld the whole into a solid, then peel the outside casing off the foil and remove that. The semi-welded batch of razors could be further refined with additional flux and welding cycles. Some carbon might be lost but there is plenty to begin with and a usable bar would be the likely result.

Clarification: I am not going to melt old sheffield steel because as I said, it's pointless. :) Known steel of equal quality is still cheaper.
I am planning to do a wootz melt someday. That is not pointless. It's still dangerous, but at least it will be worth it and with enough preparation, the risks can be minimized.

I read an account of someone who was lucky to be alive after a melt. He melted down aluminium (which still has a lower melting point than steel) and was casting into a mold. He had accounted for everything he knew of. Unfortunately he had failed to anticipate the fact that the concrete floor might have trapped moisture inside. As he was pouring into the mold, the concrete underneath got hot, the water turned to steam, the concrete exploded, the mold fragmented and a blob of molten aluminium went flying away, but missed him.

Stories like that make me cautious, and consider the risk vs benefit equation.
For wootz this may be worth it. For plain carbon steel, not so much.

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Originally Posted by Bruno

- It's freakin' dangerous. Seriously, molten steel can kill you. There are many things that are not obvious but can have catastrophic effects.
...

Carelessness about temperature gradients can make things explode, and molten steel is not something you want flying around near you.

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I don't see the problem... safety glasses are cheap, and if you are so worried about it, just get one of your kids to do it for you :)

Too much thinking going on here I do believe.

I understand the OP's interest in recycling old razors, but it's the application side of things that are the tough stuff. The majority of my frustrations have come from "unknown" steels and experimentation...but that's how I'm programmed I guess. It is much easier to work with known steels & guess what? Mike Blue & others like Butch, Bruno & Charlie made that recommendation to me when I was getting starting working with steel. They said to stick with the simple steels like 0-1 & 1095. It really is cheaper to stick with known steels if you consider time & fuel alone.

I won't suggest that my attitude is less cautious than I might imply. I have witnessed several incidents of mini-volcano proportions and others with molten metals that have gotten away from their handlers to cause injury.

The problem with ground water has plagued smelters for a few thousand years. There is an archeological story about casting a 50 ton bronze bell in China. They had cut the mold for the bell into the side of a sandstone cliff. When they poured the molten bronze it hit ground water the melters did not anticipate and it blew the top of the hill off killing all the nearby workers. There are numerous reports in near history of 30-40 workers etc being killed in the vicinity of small melts around 6 tons.

When I work with molten salts heat treating (mini volcano) even a drop of water in the top hitting the liquid surface reacts as if someone fired a gun inside the building and the action-reaction will spray molten salt all over the ceiling and anyone nearby.

I watched a group of art students carrying a 100lb ladle during a metal casting class slop just a little bit over the lip. Maybe an ounce of fluid went down the leather leg of one of the fellows onto the top of his cordura shnikes. No, he was not wearing the required complete outfit, despite his leather chaps and all the other gear. He took off like a rabbit, and does not remember ever running. The professor tackled him stripped off the shoe and dunked the foot in ice and probably saved his toes.

During a smelt of my own, we were digging around in the slag arch and a wild drop managed to crawl up my leg and down into a high top (mid calf) boot and both hands were full of tools at the time. It made for a very funny break dance moment and the burn, although small, took weeks to heal properly. Nobody helping could figure out if I was having a seizure or a stroke until we got the work done and I hopped around trying to get my boot off. Molten steel will skitter around and get into places you just wouldn't expect.

No...caution is the rule.

When you pull off a project though, you feel like you really did something!

The fantasy of pulling it off is what draws me to wanting to try melting down some ore or steel. I've got a lot to learn myself, but the seed is planted and has taken root.

Another problem you would run into is heat treating the blade of the unknow steel.... or steels in your case. A good heat treat and temper can be tricky with known steel and a heat treat recipie to go with it. Mystery steel heat treat can be very difficult and frustrating. It would be pretty frustrating to go through all that work to smelt and grind yourself a blade and then not be able to get a proper heat treat.

One more problem you would run into is decarb. Heating the steel hot enough to melt would cause a lot of the carbon in the steel to leave in favor of the oxygen. There is a good chance you would be left with a steel that didnt have enough carbon in it to heat treat it even if you tried.

Just some food for thought.

I've spent over 8 years in a foundry/rolling mill. Molten metal is EXTREMELY dangerous. However, you can melt down old "unknown" metal objects and re-use them. We would "spark" the scrap metal to see what it was comprised of. Then we would sort it into different types or categories. After they were melted down we would pour samples and "spark" them to see what the composition was. From there we could add the appropriate alloys to get it to where we wanted. At that point we would cast it into ingots and then roll the ingots into sheet and plate up to 10 inches thick.

So yes it can be done. However, it's probably not something you'd want to do at home or even have the proper tools and equipment to do so safely. You also have to do a whole bunch at a time to make it cost effective. :D

The insurance companies have convinced the local university, long known for graduating shop teachers, that casting any materials such as iron and steel are a no- no! The foundry is closed and is used for long term junk storage! The only folks seeming to be able to do hot work, other than welding, are the art students...for now!

I have developed a healthy respect for molten metals without regard to their composition.
~Richard

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Originally Posted by Geezer

The insurance companies have convinced the local university, long known for graduating shop teachers, that casting any materials such as iron and steel are a no- no! The foundry is closed and is used for long term junk storage! The only folks seeming to be able to do hot work, other than welding, are the art students...for now!

I have developed a healthy respect for molten metals without regard to their composition.
~Richard

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When I registered with the IRS I had to pick a category for my activities, which is officially 'Manufacturer of knives and hand tools', which is a subcategory of 'Metal working, with the exception of casting or mold injection'. Seems that if you want to do the latter as a job activity, that's a separate registration, possibly for environmental reasons (and permits etc).

+1 for dangerous and cost prohibitive. unless you have a lot of money and time, then it might be possible.

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Originally Posted by Bruno

When I registered with the IRS I had to pick a category for my activities, which is officially 'Manufacturer of knives and hand tools', which is a subcategory of 'Metal working, with the exception of casting or mold injection'. Seems that if you want to do the latter as a job activity, that's a separate registration, possibly for environmental reasons (and permits etc).

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Different regulators. Molten metal has it's own set of rules and laws for safety and environmental reasons.

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Originally Posted by Bruno

When I registered with the IRS I had to pick a category for my activities, which is officially 'Manufacturer of knives and hand tools', which is a subcategory of 'Metal working, with the exception of casting or mold injection'. Seems that if you want to do the latter as a job activity, that's a separate registration, possibly for environmental reasons (and permits etc).

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You had to register with the U.S. IRS from Belgium? Or does Belgium have an IRS too.

I can't speak for Bruno but if I was writing a casual post, talking about the Swedish "Skatteverket", I would probably just lazily write IRS instead of looking up the proper translation.

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Originally Posted by bluesman7

You had to register with the U.S. IRS from Belgium? Or does Belgium have an IRS too.

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I should explain. No, not the US IRS, the Belgian one (we do have taxes here too, y' know?... sadly... :) ) Like Baxxer says, in Dutch they're called 'Belastings dienst' or 'De belastingen' or certain less flattery names which I won't mention here but which revolve around the concept of them going after the little self employed people who cannot afford the big lawyers that keep the big businesses from paying taxes :)

Basically, when you want to start a business, you have to incorporate and you get a VAT number which is also your incorporation number. (actually there are 2 numbers but let's not make things overly complex).
The VAT number is what you use for taxes and accounting. You CAN run a business as a private citizen too, but then you don't get to deduct costs before taxes etc. In any case, the VAT number is also linked to your activity. This is done for census data (how many carpenters are there) and auditing (auditors may specialize in certain types of business) but also for checking regulatory requirements.

For example, if you want to do certain things which have an environmental impact, or legal requirements (such as being a certified land prospector who stakes out property lines) you have to have certain degrees, or certificates, or you may possibly have certain environmental requirements. When you incorporate, you have to choose which categories your business is active in, so that it is immediately clear if there are requirements or not. For what I do there aren't. Others may need specialized degrees or require certain environmental permits.

Thanks Bruno,

Sorry you had to revisit all that on my account.

Meh. No problem :)

I have to admit I was surprised that knifemaking was specifically recognized as a professional activity.

I use regularly an inert-atmosphere furnace that can go up to 1600 degrees, should be no problem getting a full melt on steel.

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Originally Posted by ScienceGuy

I use regularly an inert-atmosphere furnace that can go up to 1600 degrees, should be no problem getting a full melt on steel.

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Is that Tmax Centigrade? 1600 F won't be enough.

Yeah sorry, max T is probably around 3000 F.

Then you have enough, iron melts at 2700F/1482C. Having a controlled atmosphere is pretty nice.

Well it will be melting point from the Fe/C system, which will change depending on the composition but is easily found from the phase diagram, and in any case is generally under 1500 C, all the way down to under 1200 for the eutectic. We can hook up any gas, typically we use argon, but could do nitrogen or air as well.

Attachment 182575

(http://i218.photobucket.com/albums/c...arbonPhase.png)

Damn I haven't seen this chart since I was doing metallurgy as an apprentice in about 1988