... but I think there
>is now fairly compelling evidence that "blast furnaces" date from at least
>around 1200. There are some pretty early ones, 100-1200, showing up in
>Scandinavia, Germany, and Austria.
.... I do not know of any evidence for cast iron
>cannon that early. They had to be making something with all that cast iron.
Jamie Brothers
Way too early for firearms - in Europe anyway. The earliest description for
black powder is from the late 1200's. The earliest artifacts for hand
cannon or depictions of them are from the early decades of 1300. The
earlies ones are mainly forged wrought iron or cast bronze anyway.
Question (agian from a practical worker rather than a researcher!):
Are the furnaces mentioned above merely larger attempts to fine control the
processing of ore to allow for possible 'wrought steel' production? I mean
this as opposed to producing the normal wrought iron of the purpose. My
understanding is that the control of the conditions in the furnace that
allowed for the carbon content to remain 'high' was not well understood
and was more of an 'accident'. Getting a furnace load to retain even .5 %
carbon in the mix would of great value for tool / weapons end use for the
material. If you got the process wrong you could end up with way too much
carbon - and then 'cast' iron. To a medieval smith, this would be spoiled
material (you can't forge it!) and he would just re-process the load.
As a related topic (again at the risk of displaying ignorance) :
I have always refered to the material used for tool making before the
industrial age as 'wrought steel'. The material would have to be physically
created using the same hammer purification and folding of a rough bloom
that 'normal' wrought iron would. This should result in simular texture and
fine slag deposits. Difference would be that 'wrought steel' would have
higher carbon contents (where 'normal' wrought iron has almost none).
Am I entirely off base in this assumption? Is there a correct name for this
period 'wrought steel' that I SHOULD be using instead?? This may be of
considerable importance to those of us attempting to reproduce early period
tools and weapons. I KNOW that wrought iron handles much different than
modern mild steel, not only temperatures but also actual shapes are
sometimes created using entirely different methods. Everyone I know will
use modern, simple carbon steels for cutting edges, but I suspect these
are not really an accurate replacement for 'wrought steel' in fine detail.
This may not be trivial when it comes to the production of layered steels.
One of the problems you encounter when mixing wrought iron and modern
steels is 'tearing' of the iron layers during the stretching and twisting
of the layered billet. This is due mainly to the differences in flexibility
of the various materials. My * guess * is that use of 'wrought steel'
would reduce this problem. In theory, this material would also have a
different type of flexibility in final object use than our modern steels as
well. Any sword maker will tell you that the great problem with long
lengths under high stress is balancing flexibility with hardness for edge
holding.
In published descriptions, cutting edges of period artifacts are almost
always described as 'steel'. I am assuming that this term is being used to
'mean iron with carbon in it' - but still a 'wrought' type of production
method. My practical question is : Is this artifact material at all similar
to to modern carbon steels (1045 for example)?
Darrell
----------------------
Darrell Markewitz
Interpretive Program Designer
the Wareham Forge
RR # 2, Proton Station, Ont. N0C 1L0
phone/fax 519-923-9219
[log in to unmask]
Information on the 'Norse Encampment' program can be found at:
http://www.pipcom.com/wareham_forge/encamp.html
|
