Bronze/iron use in warring states/qin china.

HackneyedScribe

Ad Honorem
Feb 2011
6,543
So what? There are plenty of ways to decarburise it. The easiest is to simply toss it back into the smelter with another charge of ore.
In which case that no longer sounds like creating high carbon steel products directly from a bloomery, but low carbon bloom iron that's eventually recarburized into a finished product (a process that I already described, first by forging the low carbon bloom into a transportable bar shape). You need a finery forge to convert finished high carbon steel (pig/cast iron bars, made possible by melting them and pouring them into a 'bar' mold) into something forgeable. There are other ways but finery forges were the earliest practical way I know of.
 
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Dan Howard

Ad Honorem
Aug 2014
4,947
Australia
In which case that no longer sounds like creating high carbon steel products directly from a bloomery, but low carbon bloom iron that's eventually recarburized into a finished product (a process that I already described, first by forging the low carbon bloom into a transportable bar shape). You need a finery forge to convert finished high carbon steel (pig/cast iron bars, made possible by melting them and pouring them into a 'bar' mold) into something forgeable. There are other ways but finery forges were the earliest practical way I know of.
You don't get one or the other. In the same bloom you get everything from low carbon steel to high carbon steel. The act of bloomsmithing doesn't just hammer out the slag, it also distributes the carbon more evenly throughout the metal (it also decarburizes it by expelling carbon in the form of hammer scale). The Japanese simply broke apart the bloom and kept the pieces they wanted and discarded the rest.
 

HackneyedScribe

Ad Honorem
Feb 2011
6,543
You don't get one or the other. In the same bloom you get everything from low carbon steel to high carbon steel. The act of bloomsmithing doesn't just hammer out the slag, it also distributes the carbon more evenly throughout the metal (it also decarburizes it by expelling carbon in the form of hammer scale). The Japanese simply broke apart the bloom and kept the pieces they wanted and discarded the rest.
Why does that matter? The high carbon steel portion still isn't forgeable, ergo can't be smithed, ergo can't be decarburized by hammering. Ergo have to be recycled into something else before forging. Also do you have the quote and source that bloomsmithing distributes the carbon more evenly throughout the metal?
 
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Dec 2012
446
There are a few factors which explain the complicated transition to iron and steel.

For one, china started cast iron during the Spring and Autumn period. This iron was too brittle to be used as a weapon but certain objects like ploughs and belt hooks could more easily be cast. If you look at the data posted by hackneyedscribe, you will see that cast implements are more common early on, but malleable cast iron and steel gradually became more prevalent.

For two, china experimented a lot with their bronze alloys. Some bronze swords were bimetallic composites with harder high tin content edges cast onto a softer lower tin content spine. This may have tilted the scales in favor of bronze over iron when it comes to blades. Even the Han dynasty made arrow heads by casting hard edges onto a softer bronze tang. Also certain weapons like crossbow triggers were made of cast bronze for efficiencies sake.

Third, the warring states was composed of many different states as you may have guessed. This decentralization meant that bronze, iron, and steel all saw different at the same time in different places and the transition was rather complex.

As for Qin, there is a chance that some bronze weapons actually stood in for iron or steel ones. There are some extra long bronze blades there about 90cm in length, but I once read that these blades have something 40% tin content, which means they would shatter on impact. I would have to do some searching to completely verify this claim though. But if it were true, than it is likely that they represented iron and steel blades rather than functioned as blades themselves.

There could be a couple reasons why the terracotta warriors have a lot of bronze and not as much iron.
1) iron decays much faster than bronze
2) some sections of the tomb have been looted, and ready made steel implements would likely be the first to go
so were you able to verify the stuff about bronze weapons?
 
Dec 2012
446
So is Ian Morris's claims wrong then? I think he might be basing his claims on the fact that the terracotta army weapons are mostly bronze.