Some info On Ductile Iron

Post Reply
User avatar
Jammer
Posts: 1488
Joined: Thu Jun 02, 2011 4:04 pm
Location: Ohio

Some info On Ductile Iron

Post by Jammer »

This is some correspondence I got from a Lab Tech at a ductile Iron Foundry. I have tried to get back in touch with him to see if he will send me some of the alloy.
I've tried to attach a PDF file about Ductile Iron but it won't post it. Does anyone have a suggestion on how to post a PDF file?

For making the ductile iron at home there are a number of ways you could do it. Let me think on that and suggest some. We use two processes at Cast-Fab. Most of the iron is made using the tundish process. In this process we have special ladles which are covered, they are like a vessel of sorts. The alloy is dropped into the opening in the top, and contains magnesium ferrosilicon, an inoculant, and cover steel, and the hot metal is tapped into the hole. We fill it very quickly, about 100 pounds per second. Most treatments are 5,000 to 8,000. In the small foundry we use another converter called the Sigmat process. The vessel is a flow through type where the iron is poured in one end and travels horizontally to flow over the magnesium ferrosilicon and out the other end to be captured in the pouring basin. We discontinued another process several years ago called the open ladle treatment, and at other foundries I have used the Gazal process and the sandwich process. The open ladle treatment uses a Nickel-Magnesium alloy. It is pretty simple – you make your base iron, then after skimming the ladle and setting it on the floor, the Nickel magnesium alloy is dropped (actually slid in over the side) into the ladle where it sinks to the bottom. As it dissolves the magnesium is released. There are two alloys made by INCO for that which I have seen used: Alloy #3LC and Alloy #4. 3LC is almost pure nickel and is highly efficient. About 80 to 90% of the magnesium is recovered. #4 is only about 57% Nickel, with the rest iron (except for the magnesium). It is claimed to be by INCO as efficient but in practice it is not. We still use #4 alloy as trim additions. Both alloys contain about 5% Magnesium. Therefore since ductile iron runs say 0.035% to 0.045% Magnesium, to treat 30 pounds you would need only about a quarter pound. After treating you would need to inoculate which you could do with the ferrosilicon and do an in stream inoculation. It could be put into the sprue.

http://www.millerandco.com/products/inc ... oy3lc.html
http://www.millerandco.com/products/inc ... lloy4.html

I’m assuming you don’t want to go the route of the second vessel (tundish or Sigmat) which would be awkward for a smaller batch size. I’m also going to see what I can find out about the in mold process for you. We used it in a test at the first foundry I worked at in 1976 but I don’t have any experience with it. The sandwich method also involves a second ladle.
I will check to see if I have any Incomag #3LC. I know I have Incomag #4. If you want to try that method I will send you a piglet, they are about 2-1/2 pounds. You would have to cut it into the smaller pieces.
For PPE you would want the obvious equipment for handling the molten metal, plus the magnesium reaction is quite bright, like flashbulbs going off, for seconds to minutes. You would need tinted glasses. There is some magnesium smoke that comes off. I would suggest doing it in either an open area or have a good ventilation.
The base iron needs to have a low sulfur content. Can you check your base iron chemistry with a test heat? The magnesium may addition can be adjusted to handle some sulfur levels that are high as magnesium and sulfur readily combine, but then you will have a little more slag and dross.
quando omni flunkus moritati 8-)
dallen
Posts: 2321
Joined: Sat Jun 04, 2011 9:06 am
Location: Oklahoma

Re: Some info On Ductile Iron

Post by dallen »

open them in something like photoshop and save as a jpg or gif.
David and Charlie aka the shop monster

If life seems normal your not going fast enough" Mario Andrette
Post Reply