Question about wrought

[BlasterJoe]

Hello all,

im sure it's been covered but I can't find it. If anyone could direct me I would appreciate it.

i found a large chunk of wrought iron out in the desert one day and brought it home. No idea what it was. I spark tested it and it has grain to it.

any how my question is why did it crumble on me. Too hot or too cold. Do you have to only work with the grain or can it be altered when heated? 

any guidance would be greatly appreciated.

[Latticino]

There are different grades of wrought iron.  The lowest grade, with the most slag inclusions, needs to be either worked very hot or consolidated before working through a more "normal" temperature range.  Consolidation is compressing the billet  crossection at close to welding heat.  In any case, with my limited experience working wrought, it responds extremely well to being worked at higher temperatures (from almost white hot down to an orange heat), but tends to crack or fracture if you try to do anything but planish much below that.  Of course, once you get it up to temperature it is a pleasure to work: moves like butter and welds easily without flux.

[ThomasPowers]

Work it above the burning temperature of modern steels!

[Frosty]

Fizzy sparking heat isn't too hot for wrought.

Hmmmm, spiffy new moto, "Too hot for wrought." Let the straights figure that one out! 

Frosty The Lucky.

[BlasterJoe]

Thanks guys. When the temperature is high enough will it grow a new grain structure or should I stick with working the grain that is already established. I guess what I'm saying is does it go through the same martensite/ Austinite process a steel?

1 hour ago, Frosty said:

Fizzy sparking heat isn't too hot for wrought.

Hmmmm, spiffy new moto, "Too hot for wrought." Let the straights figure that one out! 

Frosty The Lucky.

I will definitely remember that for forever! 

[ThomasPowers]

The iron does the slag does not.  What you generally see is based on the slag content.  Wrought Iron is actually a composite material composed of iron and ferrous silicate spicules AKA  slag.  High grade wrought iron may have over 100000 spicules per sq inch cross section.  Low grade tends to have large blobs of slag in the iron matrix.

[arkie]

If I take a 1" round rod of wrought iron that is low grade, i.e., not "fine grained", would a proper way to forge it to say, a higher grade, be to flatten it out somewhat, fold and forge weld back many times all at a high heat (for wrought) such as in making damascus?

[ThomasPowers]

Wrought iron starts out as a rather trashy bloom generally containing slag, furnace wall bits, scale, unreduced ore, unconsumed fuel bits, etc---as well as the iron.

you forge that out into a Muck Bar (I've had some we forged using a wooden hammer as the bloom was so trashy a metal hammer tended to make it *splash*!)

You cut, stack, weld and forge that out into a Merchant Bar, what was often sold, hence "merchant bar"

You cut, stack, weld and forge that out into a a bar of Singly Refined Wrought Iron

You cut, stack, weld and forge that out into a a bar of Doubly Refined Wrought Iron

You cut, stack, weld and forge that out into a a bar of Triply Refined Wrought Iron---what Yellin would specify for his ornamental work IIRC.

You can continue; but remember every stage has fuel, time and wear on tools (and people) costs and scale losses as well as squeezing out a bit more slag and refining the size of the ferrous silicate spicules retained.

[arkie]

Thanks, Thomas.  I'll probably experiment with several stages of the "cut, stack, weld, forge" process and check how the refinement progresses. 

[Frosty]

Keep us posted please. Remember we LOVE pics!

Frosty The Lucky.