Bronze/iron use in warring states/qin china.

Dan Howard

Ad Honorem
Aug 2014
4,891
Australia
all very interesting, but would you say then that the idea that some how bronze weapons were the "norm" in China around 200 BC to be based on little if any evidence?
No idea. I haven't studied the distribution and deposition of swords in China. I was just commenting on the metallurgical aspects of this thread.
 

sparky

Ad Honorem
Jan 2017
5,172
Sydney
Dan Howard is right some further details
if the temperature of the furnace is high enough , the steel will flow as a viscous liquid and be able to be cast ,
that's cast iron , the carbon content is so high that it make it very brittle
modern steel making use converters to get the good stuff

primitive furnaces would heat the bloom to glowing bright cherry , it had much less carbon but was full of slag impurities which had to be beaten out of the bloom
often several times
the fuel and iron ore contain many impurities , early forge-master quickly started using wood char coal
sourcing iron ores is very tricky , northern Europe used bog iron , which require a lot of effort to obtain in some quantity
Japanese used coastal rocks , where iron had concentrated in thin layers

the most outstanding ore came from South India , it was so highly prized it was the object of a transcontinental trade
it was used to make wootz steel , a legendary product


iron making is very expensive in fuel , time and manpower , bronze making is way easier as a process , if one has the minerals
 

Dan Howard

Ad Honorem
Aug 2014
4,891
Australia
You can get cast iron from a primitive smelter. The carbon content varied in different parts of each bloom and some of it contained too much carbon to be usable. These 'cast iron' pieces could be decarburised by putting them back into the smelter and charging it with more iron ore but most cultures simply discarded them along with the slag.
 
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Jan 2016
599
United States, MO
While it is true that primitive furnaces cannot produce pure iron and thus basically everything is steel, they amount of carbon within the alloy determines how effective heat treatment can be. With something like .002 percent carbon, it will be hard to get any kind of heat treatment to affect the alloy in a meaningful way which is why these low carbon alloys are sometimes referred to as wrought iron or mild steel depending on the way it was produced.

Also, the amount of slag present in steel will have important implications for the quality of tools and weapons produced from it.
 

Dan Howard

Ad Honorem
Aug 2014
4,891
Australia
While it is true that primitive furnaces cannot produce pure iron and thus basically everything is steel, they amount of carbon within the alloy determines how effective heat treatment can be. With something like .002 percent carbon, it will be hard to get any kind of heat treatment to affect the alloy in a meaningful way which is why these low carbon alloys are sometimes referred to as wrought iron or mild steel depending on the way it was produced.
See post #21 and #23.
 

sparky

Ad Honorem
Jan 2017
5,172
Sydney
there were some trade practice such as quenching in the urine of a red haired virgin

it actually work as well if she is not a virgin or red haired , at a pinch a cow would do just as well
this is the process called nitrification and is done today using urea baths

it is a little known fact that smiths used their quenching trough to piss in , thus obtaining the stuff
 

Dan Howard

Ad Honorem
Aug 2014
4,891
Australia
Do we have any physical evidence that nitriding was actually done? I can't think of a single extant sword where an analysis shows that it was case hardened with nitrides instead of carbides. Would be interesting to follow this up.
 
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HackneyedScribe

Ad Honorem
Feb 2011
6,536
Steel comes naturally from the smelter. The carbon content varies with each smelt. Some is low carbon steel, some is medium carbon steel, and some is high carbon steel, but the proportions vary with each smelt. There is no iron at all. The only way to produce iron is under modern laboratory conditions. The Celts produced something called "blister steel" in which the carbon was very unevenly distributed. They refined it by bloom smithing, which helped to redistribute the carbon more evenly. Another technique was done by the Japanese, who took the bloom and broke it into pieces. They then picked through the pieces and sorted them according to carbon content.

It would be a good idea to read texts written by people who have actually worked with primitive smelting technologies. For European smelting, the most accessible body of work is written by Lee Sauder.

I don't see where he supports the statement that high carbon steel is easy to produce in early smelters (ergo bloomeries). He says that wrought iron (very low carbon) comes from the bloomery and cast iron (high carbon) comes from the blast furnace. Don't see where he states high carbon steel were easily produced from early smelters (bloomeries).

The rest seems to just be semantics on whether iron with very very low amounts of carbon (wrought iron) could be called steel (most people call it wrought iron), or whether cast iron is called steel. Either way wrought iron is not high carbon steel and cast iron has too much carbon and too brittle to be considered as the useful type of steel most people think about when you use the word "steel". That is, unless you count malleable cast iron which is way less brittle but that's not the type of cast iron being produced in early smelters.
 
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Dan Howard

Ad Honorem
Aug 2014
4,891
Australia
I don't see where he supports the statement that high carbon steel is easy to produce in early smelters (ergo bloomeries).
"Control of carbon content: The production of high carbon steel in a bloomery is often presented as a special accomplishment of a particular technology. In our experience it is difficult NOT to produce high carbon steel in a bloomery, and the challenge is, rather, to create a soft, low carbon iron."
 
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