[TheForge] Pure Iron vs. Cast Iron

Peter Hirst saltydog335 at aol.com
Fri Mar 28 09:32:39 EST 2008 

It might be well to specifically point up the irony (heh-heh) that iron, 
wrought or pure, has  (little or) no carbon, but steel does, and cast iron 
has even more carbon than steel does.
----- Original Message ----- 
From: "David E. Smucker" <davesmucker at hotmail.com>
To: "Sponsored by ABANA" <theforge at mailman.qth.net>
Sent: Friday, March 28, 2008 7:38 AM
Subject: Re: [TheForge] Pure Iron vs. Cast Iron


> Ekaterina,
>
> Pure iron is just that plain iron. No alloy and No carbon.  (Carbon is 
> really an alloy element but we don't think that way most times.)  As we 
> start to add carbon to iron we get steel.  Low carbon is around 0.2 of 1 
> percent carbon -- mild steel.  This is also sometimes called points of 
> carbon or 20 points.  Most high carbon steel today is around 1 percent 
> carbon (100 points.)  We often also call this a tool steel.  W1 for 
> example is 1 percent carbon.  Medium carbon steels are around a 1/2 
> percent carbon 0.5 of 1 percent or 50 points.  Steels may also have lots 
> of different alloying elements added greatly changing their strength and 
> other characteristics.  Steels can have a maximum of 2 percent carbon --  
> above 2 percent carbon, we have the cast irons.  Up to I believe the max 
> the iron can "hold" is 6.67 percent carbon.  Your ductile iron is one form 
> of the "cast irons".  Gray cast iron another.
>
> Historically there was a very common product called "wrought iron" 
> sometimes today called "real wrought iron".  It like "pure iron" had 
> almost zero carbon, maybe a very small amount.  But it did have Silicon 
> Oxide stringers in it from the manufacturing / refining process.  To 
> confuse things even more -- it was made from cast iron or pig iron by 
> removing the carbon.  Same is true today for the manufacture of raw 
> steel -- it starts out a liquid cast iron from a blast furnace -- also a 
> lot of recycled steel is added.
>
> Hope that helps a little.
>
> Dave Smucker
>
>
> ----- Original Message ----- 
> From: "Ekaterina Harrison" <ekaterina at wildblue.net>
> To: <theforge at mailman.qth.net>
> Sent: Friday, March 28, 2008 12:50 AM
> Subject: [TheForge] Re: File Making, sniffing up wrought iron
>
>
>> Hi All,
>>
>> I must admit that some of this is going over my head. <sigh> Perhaps 
>> this was already answered and I missed it.
>> I have spent a few years working in various foundries and have poured 
>> some ductile iron. However, I really did not get a chance to find out  as 
>> much as I had wanted to about the various aspects of iron. Perhaps 
>> somebody here can answer this - What is the difference between iron  that 
>> is cast and what you are referring to as pure iron?
>>
>> Ekaterina
>>
>> On Mar 27, 2008, at 8:26 PM, theforge-request at mailman.qth.net wrote:
>>
>>>
>>> Message: 2
>>> Date: Thu, 27 Mar 2008 14:10:52 -0400
>>> From: "David E. Smucker" <davesmucker at hotmail.com>
>>> Subject: Re: [TheForge] Re: File Making, sniffing up  wrought iron
>>> To: "Sponsored by ABANA" <theforge at mailman.qth.net>
>>> Message-ID: <BAY137-DAV227345FD9B7D86414EDBCADFE0 at phx.gbl>
>>> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
>>> reply-type=response
>>>
>>> Frosty,  I believe the pure iron made today is being made via an 
>>> electric
>>> arc furnace.  It is really being produced as "transformer iron" for  use 
>>> in
>>> some types of transformer and other magnetic devices.  It is  produced 
>>> in
>>> sheet form.  This is quite a bit of this produced but not as much as 
>>> some of
>>> the other transformer irons with high Si content.  (Pure Si, not the 
>>> oxide.)
>>> The blacksmithing pure iron was (is) produced by taking some heats  of 
>>> this
>>> material and running it to bar stock.
>>>
>>> To the best of my knowledge there are no Bessemer Furnaces still in
>>> operation.  (Air Blast)  There are a lot of Basic Oxygen Furnaces 
>>> operating
>>> producing about 60 % of the worlds raw steel.  Some have called BOF  the 
>>> "son
>>> of Bessemer" as the blast is now Oxygen vs. Air.  The BOF can take a 
>>> feed of
>>> about 1/3 scrap vs. little or no scrap in the Bessemer.  In the BOF  you
>>> don't have to heat the N2, so you can melt scrap instead.
>>>
>>> Dave
>>> ----- Original Message -----
>>> From: "Jerry Frost" <akfrosty at mtaonline.net>
>>> To: "Sponsored by ABANA" <theforge at mailman.qth.net>
>>> Sent: Thursday, March 27, 2008 1:27 PM
>>> Subject: Re: [TheForge] Re: File Making, sniffing up wrought iron
>>>
>>>
>>>> This leads me to delve back into the recollections that I was  mistaken
>>>> about regarding when wrought was last produced in the US. (lousy 
>>>> sentence
>>>> but understandable I hope)
>>>>
>>>>> From what I recall reading; after the bessemer process
>>>> became wide spread, production of wrought fell off sharply and mild 
>>>> steel
>>>> became more and more the norm for construction and other things 
>>>> wrought
>>>> was used for. Still, there was a large market for wrought iron and  for 
>>>> a
>>>> period bessemer processed pure iron was sold as wrought, later 
>>>> specific
>>>> amounts of silica was added to make "bessemer wrought." (I'm using a
>>>> descriptive phrase here, that's almost certainly not what it was 
>>>> actually
>>>> called)
>>>>
>>>> Again, my memory is probably not clear so I'm sure details are  wrong. 
>>>> I've
>>>> looked through my bookmarks and read myself cross-eyed but can't  find 
>>>> the
>>>> link I probably lost it in the last crash.
>>>>
>>>> Anyway, I strongly doubt fresh wrought is being produced the way  they 
>>>> did
>>>> it 150 years ago. The ore or scrap is probably refined and purified 
>>>> via
>>>> the Bessemer process and silica added back in to make up "wrought". 
>>>> It's
>>>> them refined under rolls rather than hammers.
>>>>
>>>> Pure iron is probably taken out of the process before alloying  agents 
>>>> are
>>>> added and actually requires less labor, materials and fuel to  produce. 
>>>> But
>>>> as all small batch products costs more.
>>>>
>>>> I'll go sit quietly now.
>>>>
>>>> Frosty
>>>> -------------------------------
>>>> If it ain't forged
>>>> it ain't real.
>>>> Wrought iron is.
>>>> The FrostWorks
>>>>
>>>> Meadow Lakes, AK.
>>>>
>>>>
>>>> From: "Andrew Vida" <osan at netlabs.net>
>>>>
>>>>> The front page is interesting in that mewonders if they have  confused
>>>>> pure iron with wrought.  To wit, it states:
>>>>>
>>>>> "Pure Iron is a high-purity iron that is very ductile and the 
>>>>> preferred
>>>>> material for forging and decorative metal work. While very popular  in 
>>>>> the
>>>>> first half of the 20th century, its use was reduced by the 
>>>>> development of
>>>>> new steel alloys and high production costs."
>>>>>
>>>>> I do not recall pure iron being popular in the era up to 1950, but
>>>>> perhaps I am mistaken.  Also, referring to it as "ductile" rather 
>>>>> than
>>>>> malleable leads me to suspect.  Wrought iron is ductile (uni-axial
>>>>> deformable) whereas pure iron is malleable (multi-axially 
>>>>> deformable).
>>>>>
>>>>> Just an observation.
>>>>>
>>>>> -Andy
>>>>>
>>>
>>
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