Wrought Iron vs Cast?
- Thread starter DonL
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Doug Lester
Well-Known Member
They're not even close to being the same. Functionally, wrought iron can be forged and cast iron would crumble if you tried it. It is suitable only for casting. Wrought iron gets it's name from being forged, or wrought, to reduce the impurities and carbon content in it. Wrought iron also welds much easier. Cast iron welds with a torch or a stick welder with difficulty and not at all by forge welding. It wouldn't surprise me at all if welding cast iron had it's own certification separate from steel welding. Chemically, both have silicate strands throughout them. Wrought iron has essentially no to up to 0.2% carbon, though I think wrought with any measurable carbon content is also referred to as wrought steel, reserving the term wrought iron for the product without any carbon in it. Cast iron has a carbon content of over 2% and may have graphite inclusions as well as silicate strands which makes it much more brittle. It's only slightly more refined than pig iron, which is iron as it comes from the furnace.
Doug
Doug
ChuckBurrows
Well-Known Member
With all due respect to Doug there are in fact several different types of cast iron, some even that is malleable and even forge able, but in general the most common cast iron is the high carbon brittle type.
As for wrought iron - what makes it wrought is the process, take cast iron pigs heat and beat until it is workable. While it is common to consider wrought iron being less than .03% or so carbon, old wrought that I and others (including Rick Furrer, who has probably studied the subject as much as anyone alive) have had it carbon out up to .06%. As for wrought steel - perhaps a new term but I have never seen the term used in the historical record (doesn't mean it wasn't used, but if so it must be rare.
As for wrought iron - what makes it wrought is the process, take cast iron pigs heat and beat until it is workable. While it is common to consider wrought iron being less than .03% or so carbon, old wrought that I and others (including Rick Furrer, who has probably studied the subject as much as anyone alive) have had it carbon out up to .06%. As for wrought steel - perhaps a new term but I have never seen the term used in the historical record (doesn't mean it wasn't used, but if so it must be rare.
Doug Lester
Well-Known Member
You may be right on the wrought steel being a modern term, Chuck. I think that I picked it up in a paper that I downloaded. It was described as a low carbon steel with silicate strands running through it and was use to differentiate it from wrought iron with essentially no carbon in it. Forgot about there being more than one form of cast iron also but the more brittle type is what most people think of when they say cast iron. As with cast iron stands or cookware.
Studying how steel was made "way the heck back when" is getting interesting. A lot more methods that I had originally understood. Ran into a discussion recently, I think Rick was involved somewhere as it's up his alley, about an old style furnace that was used to burn the carbon out of cast iron, or more correctly high carbon iron from a bloom. I had always understood that that process wasn't done until the Bessemer furnaces were developed. I find it amazing what these people did considering that they had no idea of what they were really doing.
Doug
Studying how steel was made "way the heck back when" is getting interesting. A lot more methods that I had originally understood. Ran into a discussion recently, I think Rick was involved somewhere as it's up his alley, about an old style furnace that was used to burn the carbon out of cast iron, or more correctly high carbon iron from a bloom. I had always understood that that process wasn't done until the Bessemer furnaces were developed. I find it amazing what these people did considering that they had no idea of what they were really doing.
Doug