Told you guys!
We were right there up front.
WHY THE ART WAS LOST
The discovery that vanadium is extremely effective in producing Fe3C banding in high-carbon steels17 was aided by the accidental use of Sorel metal as a raw material for making the small ingots. Sorel metal is a high-purity Fe-C alloy, containing 3.9-4.7% C, marketed by Rio Tinto Iron and Titanium America, Chicago. The alloy is produced from a large ilmenite ore deposit at Lac Tio on the north shore of the St. Lawrence River. Analyses of several batches of the Sorel metal has found that it consistently contains a few hundred ppmw of vanadium impurity. Apparently, the impurity is contained in the ilmenite ore.
This suggests the possibility that the low levels of vanadium found in the genuine wootz blades of Table III may have resulted from ore deposits in India where the wootz steels were produced.
One of the big mysteries of wootz Damascus steel has been why the art of making these blades was lost. The vanadium levels provide the basis for a theory. Based on our studies, it is clear that to produce the damascene patterns of a museum-quality wootz Damascus blade the smith would have to fulfill at least three requirements. First, the wootz ingot would have to have come from an ore deposit that provided significant levels of certain trace elements, notably, Cr, Mo, Nb, Mn, or V.
This idea is consistent with the theory of some authors who believe the blades with good patterns were only produced from wootz ingots made in southern India, apparently around Hyderabad.
Second, the data of Table IV confirm previous knowledge that wootz Damascus blades with good patterns are characterized by a high phosphorus level. This means that the ingots of these blades would be severely hot short, which explains why Breant's9 19th century smiths in Paris could not forge wootz ingots. Therefore, as previously shown,successful forging would require the development of heat-treating techniques that decarburized the surface in order to produce a ductile surface rim adequate to contain the hot-short interior regions.
Third, a smith who developed a heat-treatment technique that allowed the hot-short ingots to be forged might still not have learned how to produce the surface patterns, because they do not appear until the surface decarb region is ground off the blades; this grinding process is not a simple matter.
The smiths that produced the high-quality blades would most likely have kept the process for making these blades a closely guarded secret to be passed on only to their apprentices. The smiths would be able to teach the apprentices the second and third points listed, but point one is something they would not have known. There is no difference in physical appearance between an ingot with the proper minor elements present and one without.
Suppose that during several generations all of the ingots from India were coming from an ore body with the proper amount of minor elements present, and blades with good patterns were being produced. Then, after a few centuries, the ore source may have been exhausted or become inaccessible to the smithing community; therefore, the technique no longer worked. With time, the smiths who knew about the technique died out without passing it on to their apprentices (since it no longer worked), so even if a similar source was later found, the knowledge was no longer around to exploit it.
The possible validity of this theory could be examined if data were available on the level of carbide-forming elements in the various ore deposits in India used to produce wootz steel.
.D. Verhoeven, A.H. Pendray, and W.E. Dauksch. (1998). The Key Role of Impurities in Ancient Damascus Steel Blades. Journal of Metals. 50(9). pp.58-64. [1]
I am sure, though, that there are people who would appreciate the finer points of these things and understand and appreciate them a lot better than I ever could.
