Supporting > Casting

Casting Gray Iron

<< < (6/6)

Casting Iron:
Thanks to all for the kind comments.

That is a great looking foundry (Romac), with some sophisticated methods, such as the laser guided pours, etc.

I read several casting journals regularly, and there is a good market for ductile iron castings, since they often can meet or exceed the strength of steel, but with a lower cost.

Kory Anderson (150 hp Case guy) uses ductile iron for flywheels and other items, but I really only need ductile iron for crankshafts.

It is exciting to see US-based foundries with high quality products, and this on-shore capability solves the supply chain problems that we have seen in recent years, as well as provides jobs for folks located here.

I am in the wastewater renovation business (electrical side of things), and there is a lot of money involved, given the large size of many plants, and the dedicated operational and repair funding that the EPA requires.

Learning the methods of making ductile iron has been more difficult than learning to pour gray iron, and I have had to pick out bits and pieces of critical information about how to do it on a small scale from suppliers and an occasional person who has worked in iron foundries.
Some folks know ductile iron on a large scale, but can't really give helpful information about how to do it on a small scale.
I think I have it figured out, and I think I have all the materials required to do it successfully, so we shall see.

I feel like preserving the knowledge of how to pour gray iron is critcial to keeping the model engine hobby alive in the US, and pouring iron engine parts is just downright fun.

I hope to get to the point where I can make more iron castings in the near future.

Thanks for everyone's interest.

Pat J
.

Jasonb:
I would have thought you could use Ductile iron on more parts than just crankshafts Pat.

Any cast part that is long and slender will be far more durable and less likely to get broken than if it were made from regular grey iron. Other kit producers use it for things like valve rockers & posts and on the monitor the pivoting arm of the cam follower and the governor weight would be best done in ductile.

Casting Iron:
The ductile iron casting process is more involved than just casting plain gray iron.
The sulphur has to be controlled, and the inoculation process I will use takes place in a lined container, which will be somewhat wasteful just due to the nature of the setup.
And I have a finite amount of ferromagnesium, and don't have a supplier for that.

So there are some challenges ahead, such as verifing the exact process in a backyard setting (I have seen it done, and so I understand how to do it).

For long thin parts, it will require a lot of fluidity, and I have an additive for that too, but again, a finite amount with no supplier.

One of the biggest challenge for me, and I think one of the biggest challenges for hobby casting folks, is finding small quantities of commercial materials.
Generally, one has to know someone in the industry in order to get some of the materials.
I have done a lot of begging to get what I have.

You can purchase materials by the 55 gallon drum, or by the ton (sand), but smaller quantities are very difficult to source.

The ductile iron making process is a volatile exothermic reaction, and the exact volatility depends on the percentage of magnesium contained in the additive.
One wants enough magnesium to give good results, but not so much magnesium that it melts your entire reaction chamber.
I think I can make ductile iron, but I don't think I would want to cast it routinely, especially without finding a readily available supplier.

It is very difficult to find art-iron folks who do ductile iron, and the ones I have found don't really discuss how they do it.
It is a very secretive thing, perhaps just from a general lack of knowledge.

Here is a video of a ductile iron attempt.
It was not an explosion in the ladle, but rather just a very aggressive reaction, and way too agressive in my opionion.
I can't find anyone to even discuss this attempt, but obviously, great caution must be used with this process.

http://www.youtube.com/watch?v=SQLAdOg6V5g

Casting Iron:
I think a typical small reaction chamber for making ductile iron can be seen in this video at 10:20.
The chamber would need to be lined with 3,800 F plastic refractory, and it must have a pocket on one side for the ferromagnesium.
The reaction is relatively mild, and would be messy without a tall vented chamber.

And if you don't control the sulphur, then you are not going to get ductile iron.

It should be noted that the IR (infrared) coming out of a hot furnace, from the crucible, and from the top of the melt, is very intense, and without wearing shaded gas welding glasses, you can have sunburn in the eyes after a single exposure.

http://www.youtube.com/watch?v=xrLkm243_-8

Navigation

[0] Message Index

[*] Previous page

Go to full version