I started to melt some Cast Iron today

[dallen]

(08-24-2013, 05:31 PM)oldgoaly Wrote: DA
is the ferro-silicate (I don't remember the full name) supposed to take care of that white iron (haven't heard that term before)
part looks workable, The tank hanging? waste oil? Thanks for sharing your work!

Goaly, its Ferro Silicon it helps with the machinabililty of the iron, thin sections of Cast Iron are hard to keep from turning out hard unless you work with it a lot, Cast Iron is not different then any other metal it has its own qwirks that you have to learn, its been well over a year since I melted any so its been a fun.
yes the hanging tank is for oil but today it had Diesel in it, I have burned used oil by its self but prefer to mix it with #2 so it flows better, the hanging tank just gives me a little help at the syphon nozzle.

DA

[dallen]

here's what I found hiding inside the casting after I got some of the skin cut off, bunch of holes, I figure its from turbulence from me not keeping the spure choked off with metal.

The bright shiny places are where the cast turned hard real hard. the rest machines pretty decent I drilled the center hole and the large bit the chips came out in little curls

Anyway here's the photo

[Hawkeye]

I learned about white iron when I picked up a cast weight at the scrappers. About a foot long and just over 2" square. The first thing it did was eat a 10' bandsaw blade. The shaper liked it fine, but it was a bear to machine otherwise.

After I read about white iron, it made sense. When the foundry has iron left over at the end of a pour, they can pour it into molds for things like weights that don't matter. Then, they're more likely to chill it fast to get the mold empty. The result is white iron. Fine for weights, scary for raw material.

[dallen]

Mike

I've poured iron before that had a hard skin so this is nothing new other then the fact that its just in two spots in the part which is the two edges where you see the bright shiny metal, harder then toolpushers heart. the rest machined fine, the center bore which gets threaded did so with no problems.

the porosity is something (I won't say new i have a backing plate that is full of slag inclusions that I poured) else. it may be from steam not sure on that one, the shrinkage I know how to deal with that. Anyway I almost got a useable part out of the deal, almost.

DA

[dallen]

here's a couple of photos of the casting after I found an insert that I would cut thru the hard corner edges, the middle machined great last night.

the more I look at this the more I'm thinking its steam from using the green sand and it being so fine that the steam couldn't escape and the fact that I didn't put any vents in the mold, which is something that I usually do even if the mold doesn't need it.


This think looks like Swiss Cheese the deeper you get into it the bigger the holes get.

I ended up using a big TPG 432 I don't know any thing more then that about the inserts I was given them by the guy at the local supply house they were a sample that had been dropped off, he knows I like samples so he tosses some my way every now and then, just so happened I had a bar that I had milled down from 1" square to 1X.5 that a friend had pawned off on me saying he couldn't use it.

Right photos of swiss cheese

[EdK]

It looks like metal termites were feasting on that.

Ed

[dallen]

Yea but at least its and excuse to do it again. gotta go tear the burner apart I didn't use as much diesel as I though I would think maybe I may still have a bug in the fuel line.

[oldgoaly]

they almost are inline, is that where the parting line was?

[dallen]

the parting line was the edge under the Hex just about all those holes but the holes are all over the part is just that they show up pretty bad in two places, the end that I have ahold of I faced it off and have holes showing up in it. and it was in the bottom of the mold.

I'm thinking that I may repour it tomorrow morning will have to see what the weather brings. anyway I'm going to modify the pattern so I can put a core in it so I don't have to drill thru 2.5 inches of Cast Iron.

DA

[dallen]

here's what I started the day out with by casting this nut in Cast Iron, from the looks of it I got a solid casting
total melt time was 35 minutes.


so far I've not found any hard spots or white iron.

DA