What iron foundries add to cast iron.

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100model

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Years ago I went to the preview day for a huge auction of a foundry that made auto parts in Australia. They also made ductile iron crankshafts so have a close look at the 2:27 mark and see the list of additives. Also in the video it shows the patterns for parts of a car, it is something that is rarely seen outside of a foundry.

 

GreenTwin

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They would not add sulphur to the mix to make ductile iron.
You have to have a very low sulphur level for ductile iron, and you add things like calcium carbide to reduce the sulphur content very low in ductile iron.

The list is very interesting.
Is that their ductile iron recipe?
I don't see sulphur on that list.

The drum labeled "sulphur" actually contained iron pyrites, which I guess is not sulphur?
Sulphur would be yellow.

Great video.
The iron would have to be very fluid to fill those crankshaft molds.

The Speedy Twin engines could be purchases with either a cast iron crankshaft (I assume ductile iron, but not sure), or for a pretty significant cost adder you could get a steel crankshaft.

Thanks for posting.
And some comments from olfoundryman; how cool is that?

As the foundries move elsewhere, I guess us backyard iron foundry guys are keeping the iron-art alive.

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100model

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I don't see sulphur on that list.

The drum labeled "sulphur" actually contained iron pyrites, which I guess is not sulphur?
Sulphur would be yellow.
Iron pyrites is the common name for iron sulfide and when added to molten iron will raise the sulphur level. The reason why they add sulphur
is scrap steel is melted and recarburized to cast iron level but when steel scrap is used the melt can have very low sulphur levels. That is great for ductile iron but normal cast iron can have chilling because ferrosilicon does not work well at very low sulphur levels. So a foundry has two choices to get soft iron, 1. add sulphur to a normal level so ferrosilicon works 2. use very expensive custom blend ferrosilicon with other additives that work at very low sulphur levels.
The list is very interesting.
Is that their ductile iron recipe?
That list is a screen shot from the auction catalogue I downloaded which had well over two hundred pages. The list is what was left over when the foundry closed down. In a production foundry like this one a sample is taken from every melt to see what is under or over their tolerances in the ingredients they add. They then add trimming amounts to bring the iron to specs.
The iron would have to be very fluid to fill those crankshaft molds.
That is the beauty of having an induction furnace, you can make the iron as hot as needed to fill up the crankshaft mold and being a production foundry temperature would be checked often to make sure they do not have cold shuts and misruns.
I guess us backyard iron foundry guys are keeping the iron-art alive.
That is so true! but there one negative effect when these foundries close down some of the foundry suppliers close down as well. I used to think it was hard to get foundry supplies but now the choice of suppliers is a lot less it has become a lot harder to get supplies.
 

GreenTwin

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That is some great information !
There is so much to learn, and it definitely is an art, with perhaps a little science mixed in.

I would like to be able to cast steel, but I feel lucky to be able to do gray iron.
I was able to learn gray iron due to folks like 100model helping me learn it, and that is much appreciated.
I am not sure if I would have figured it out without help.

There are still a number of small suppliers in the Birmingham Alabama area (last time I checked a few years ago).
Alabama was the king of iron pipe in the world for many years, with huge foundries like Sloss (now a museum).

I looked for coke (coal heated in the absence of oxygen) for years, because that was the only fuel I was aware of in the early days that could be used to melt iron. I never found anything less than a semi-truckload, so I kept looking, and discovered oil burners like 100model's.
A few years ago, my niece found a new job. I told my sister "That is great, where did she end up?".
"ABC Coke in Birmingham" my sister said. Boy could I have used that connected in 2012.

And we have a few companies in town that apparently cater towards the design and materials for very large heat treating ovens, I guess for the mini mills in this area, or perhaps for bigger mills elsewhere.

Casting steel is definitely a black art, as if casting gray iron was not mysterious enough by itself.
If I could, I would operate an induction furnace, but that would take a pretty good sized diesel genset.
I have looked at used gensets, and they are somewhat reasonable, depending on what your definition of "reasonable" is.

I would settle for ductile iron over steel, if I could find a consistent source for Nickle Mag.

I will go back and study your list again.
Much to learn for sure.

Pat J

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ajoeiam

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blank (like some others I've noticed)
snip

That list is a screen shot from the auction catalogue I downloaded which had well over two hundred pages. The list is what was left over when the foundry closed down. In a production foundry like this one a sample is taken from every melt to see what is under or over their tolerances in the ingredients they add. They then add trimming amounts to bring the iron to specs.

snip

Fascinating discussion guys!
Any chance of one of you including this 'catalog' that has been mentioned?

Dunno when/if I'll get to casting but I'm intrigued and would like to know.
(I know - - - I'm a nosy git but I've been asking about things for lots of years and don't think I'll be able to quite any time soon - - - grin!)
 
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The Sulfur barrel seems to be used a trash can. Sulfur is something to be avoided at all costs is any Iron/Steel composition. Is lway listed as LESS then X%
 

GreenTwin

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Iron pyrite appears to be what is called "fools gold", which is a mineral composed of iron and sulphur.

So it appears that the barrel contains part sulfur (in a mineral "fools gold" form), and thus the "sulfur" label on the drum.

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GreenTwin

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I found this on a website description.
The website won't open, but I captured the text.

Pyrite as the increase sulfur agent in smelting & casting As the increase sulfur additives, high grade pyrite (FeS2) is used in smelting and casting. It effectively improves the cutting performance and mechanical properties of steel, not only make it require less force and temperature when cutting, and thus prolong the service life, but also lower the surface roughness and better at chip disposal.

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100model

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I would settle for ductile iron over steel, if I could find a consistent source for Nickle Mag.
Did you notice in that list there was no nickelmag? Nickel is a very expensive metal so they use magnesium ferrosilicon or other alloys similar to that one which are cheaper.
Any chance of one of you including this 'catalog' that has been mentioned?
That list I showed is for the alloys added to cast iron. The rest of the list shows endless machine tools used to machine crankshafts, disc brake rotors etc and everything else used in a foundry including the kitchen sink.
effectively improves the cutting performance and mechanical properties of steel, not only make it require less force and temperature when cutting, and thus prolong the service life, but also lower the surface roughness and better at chip disposal.
Sulphur is one additive to make free cutting steel but most people don't know that lead is added to steel to make it free cutting. The down side to this is if this steel is welded the joint is very brittle. The data sheets usually tell you this but most people don't know this and wonder why it happens. Another downside to using free cutting steel that contains lead, is when remelted and recarburized to make cast iron that iron is super brittle and totally useless. The same goes for remelting scrap cast iron. Years ago I used cast exhaust manifolds that were on cars that used leaded petrol, so long before the internet it took me a while to figure out why my castings were so brittle. So how much lead can ruin a cast iron melt? 2-3 grams of lead in 1000 grams of cast iron.
 

GreenTwin

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I found one site that said Nickel Mag has a shelf life, and will last much longer if kept in an airtight container.

I have heard that Nickel Mag is expensive, so I guess I need to look at an alternative.
One supplier mentioned an alternative that had ferrosilicate in it, but I told him that I have to control the ferro very closely to avoid excessive shrinkage.

Perhaps the magnesium ferrosilicon could cause the same problem (too much shrinkage), or perhaps just omit the normal dose of ferosilicon, and use the magnesium ferrosilicon to get the ferro and the magnesium in a single additive.

I use leaded steel for making bolts and nuts from hex stock.
Otherwise I don't use lead in the shop.

For gray iron stock, I use cast iron motor end bells exclusively, and they break without too much trouble, and seem to provide a consistent melt and castings that machine easily without hard spots.

I think that is one of John Campbell's rules for good castings; use consistent high quality scrap.

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