Hello, this is ipostswords and this is going to be a rather long and in-depth video on woodz steel,
its history, metallurgy, and production. For the most part it's going to be based upon
excellent academic work done by Anne Feuerbach and metallurgical experimentation by John Verhoeven.
before we get into the meat of this video a quick note on the confusing state of affairs regarding
the term "Damascus steel". These days many knife and sword makers market their products as being
Damascus steel, and in the modern world this means pattern welded steel. Pattern welded steel is made
by folding together two dissimilar steels and etching them one steel edges more readily than
the other and the contrast between them will cause a visible pattern of bright and dark lines
however historically, prior to around the 18th century, Damascus steel was also used to refer
to wootz or crucible steel which was produced all over South Asia East Asia and the Middle East. In
order to be able to differentiate between these two forms of Damascus steel I will be using the
nomenclature of pattern welded steel and wootz steel. let's begin with the obvious question;
what is wootz? The metallurgical identification of wootz is problematic as no single criteria can be
used to differentiate between crucible steel and decarburised wrought iron. in order to confidently
say whether a sword is a crucible steel or not the blade must be polished and then etched
in nital and examined under low magnification microscopy the presence of spheroidized cementite
is considered evidence of crucible produced steel Wootz can occur in two different forms according
to Anne Feuerbach. Soft wootz, with less than 0.8* percent carbon and hard wootz with greater
than 0.8* percent carbon .the vast majority of pattern presenting roots and historical
roots is hard wootz whereas a majority of crucible steel that produces no pattern is soft wootz this
was common in the early days of crucible steel production. the reason you need so much carbon in
order to create wootz is the fact that steel will not liquefy until an extremely high temperature,
that temperature is reduced by adding by adding carbon. you can get wootz to liquify
at a reasonable temperature for the technology of the day the appropriate amount of carbon ended up
being somewhere around 1 to 1.8% as a result this is where we see most hard wootz having
its carbon content range. the names pulad, fulad and bulat derive their meanings from the Persian
word for purified fittingly wootz also contains lower levels of slag than other types of steel
particularly bloomery iron and decarburized in Europe and over the world however if wootz was
produced using decarburization cast* iron as a source of iron this can introduce slag into
the final product the earliest known swords made from crucible steel date from the first century
Common Era in Luristan** these were identified by the presence of spheroidized cementite in their
microstructure metallurgical analysis indicates that they would not have formed a watered pattern
if they were etched the next archaeological evidence we have of crucible steel swords
shows up in the third to fourth century of the Common Era in the Russian North Caucasus these
exhibit similar signs and would not have been pattern forming moving along in history there's
a seventh century sassanid sword or Persian sword made of crucible steel it's a straight
double-edged sword of a so-called pistol grip in the classic style of the time this example when
edged in night all showed a true watered pattern with a fine pearlitic matrix in to spare us with
bands of spheroid cementite moving onwards once again an eighth or ninth century persian blade
currently in the Metropolitan Museum is also made of wootz with both spheroidized cementite
and ferrite present in its microstructure. Wootz was made in did many different places throughout
history but in the context of the aforementioned ancient finds the vast majority of wootz came
from several key regions which was described in ancient texts such as those by al Kindi beiruni,
pliny the elder and others these texts claim the iron was generally sourced from either ceylon or
Khorasan and was then subjected to local variation in particular there were forged in merv, bukhara,
South India, Hyderabad, and Isfahan different processes were used to create wootz in these
regions with different crucible materials constructions and varied crucible charges
some mentions of unique Indian steel even date back to the 3rd century before the Common Era
in the form of white steel given to Alexander the Great by Indian rulers. let's move on to how the
crucibles were constructed for the most part a clay crucible will be filled with a charge which
would contain iron often a mix of soft and hard iron referred to our kindi as male and female
iron as well as some form plant matter such as rice husks pomegranate peels wood chips leaves
or vined this organic matter served two purposes firstly to provide carbon to the steel without
which it could not melt and without which it could not produce steel the second purpose was
to produce gases as they pyrolyze which protected steel from the atmosphere of the furnace some
processes such as the deccani process utilized in hyderabad used glass as a protective flux. the
crucibles were heated for anywhere between six hours as in the South Indian process to around
two days in the decani process or as many as six days in the Isfahan process. wootz buttons present
two distinct regions on their surface with the top of the button having a rough appearance and
often being used to form the spine of weapons and the bottom of the button having a finer texture
often being used for the edge on both surfaces a fine network of dendritic fibers is visible,
indicative of the heterogeneous crystalline structure of wootz if a crucible charged failed
to show good patterns after window polishing they were sometimes subjected to further heating in the
Isfahan process the wootz ingots were taken from the crucibles after firing and placed
in a heated room or compartment for two days in order to temper them and relieve stresses
prior to forging this was simply to prevent them breaking if they were mishandled isfahan wootz is
particularly well known as as khorasani steel the most famous of Persian sword makers in fact hailed
from Isfahan he was known as assadallah and he was active during the reign of shah abbas there's
an interesting legend as to how he rose to such prominence as to be the most famous of persian
sword makers according to this legend shah abbas held a competition with the intention of finding
a new shamshiraz -or swordsmith for his court in order to root out the best of the best he
ordered a prize for sword smith who could cut an iron helmet given to him by an ottoman sultan in
half without damaging their sword all contestants failed but one assadallah whose names literally
translates to the lion of God approached the helmet swung and cleaved it in to without
rolling in edge my Assad Allah shamshir also has its own fascinating bit of history I can't
confirm this as it happened 400 years ago and documentation is spares however it makes sense
given where this sword was found in Poland and the fact that it's made by assadallah, signed by Assad
Allah under Shah Abbas, and has the right sort of wootz for that era. Anyway, on to the story;
in 1601 Zygmunt trzeci Waza or Sigmund the third the king of Poland sent an Armenian merchant Sefer
Murotovich on a commercial mission to Isfahan with the instructions to procure rugs woven with
the Royal Arms which we actually in the krakow Castle these days as well as costly fabrics tents
and weapons specifically sabers with blades of watered steel this is likely one of those watered
steel blades it's from the correct period has the correct form and is from the correct country of
origin it's also made from the highest grade of wootz by the very best of makers the steel is
highly spheroidized with cementite particles forming very distinct rafts the bright white
lines you can see here it's characteristic of a assadallah work from around 1600 to 1607 it was
also found in Poland which fits the above theory as I mentioned this has a particularly rare and
valuable form of wootz the wootz on this sword is known as Kara Khorasan Wootz or black Wootz
from the Khorasan region it has a distinct styling being dark with far light-tight swirls which are
formed when the specific ore is used to make a specific type of Steel which is forged in a very
particular way this sword has gone through some resharpening and as a result it has some damage
to the signature regardless it's still possible to read it was made by a assadallah you'll note that
on the edge of this blade you can see an extremely dense parallel cementite raft structure the high
density cementite in this region is characteristic of wootz swords produced by assad allah the
intensely forged edges are more resilient and more resistant deformation as well as being able to be
made sharper as there's an increased proportion of cementite to sorbite in that region root swords
have a characteristic pattern such as the one shown on screen from leo figiels book "on damascus
steel" we can compare these patterns which are described as being made by assad allah to the
assad allah' in my collection you can see the same compressed grain structure on the edge and
the mottled spirals in the grains of the body of the sword these are indicative of processes used
by assad allah' in order to produce a fine edge and a strong body the secret to producing wood
steel was lost for a long time as the all sources dried up around 1750 and wootz production ground
to a halt crucible steel was still being made but it lacked the distinct patterns
in the steel which had served as a guarantee of quality in the part it is only recently through
the combined efforts of John Verhoeven and the late Al Pendray that it was revealed that the
trace amount of carbide forming elements in wood steel was responsible for the pattern
formation in particular the pair discovered that vanadium was a vital alloying element in pattern
formation recently Verhoeven actually revisited the topic with a 2018 paper titled Damascus steel
revisited in which experimentations solidified his claim the internal banded microstructures
resulted in micro segregation of vanadium between dendritic and inter-dendritic regions of the ingot
during solidification vanadium therefore acts as a nucleation point for cementite sphere inflammation
leading to linearly aligned band cementite after forging in other words vanadium acted as
a nucleation point where cementite carbide could form into a sphere where there was a small amount
of vanadium you would get spherical carbides forming these hard carbides would form into
bands or rafts which would then be aligned during forging and create the distinctive cementite
patterns which appears bright white lines on wood steel I've not gone into too much depth
in this video and there's a lot more that could be said including detailing different ways that each
region produce roots steel if you're interested I can make a whole series of videos on this topic
as it's something I personally find fascinating this has been a top-level overview of some of the
history of wootz steel some of how its produced and some of the swords made by famous Smith's I
hope you've enjoyed the video because that's all I've got for you today until next time stay sharp