Ethnographic Arms & Armour - View Single Post

urbanspaceman · 17th August 2021, 09:44 PM

It was vital that the correct leaves and twigs were added to the crucible when making Wootz. Just adding charcoal/carbon didn't do it as there needed to be trace elements of Molybdemum, Vanadium and Chromium along with nanowires of cementite.
What is produced is a hypereutectoid steel which is hard, high carbon steel that remains malleable.
Contention exists over whether Wootz blades were quenched at all. It has been suggested that: "if high carbon Wootz is heated to the extent that a substantial amount of the carbides are dissolved, then upon quenching and tempering its microstructure would turn into a proverbial dog's breakfast with very uncertain mechanical properties".
Dr. John Verhoeven continues:
There is a general myth in some of the popular literature that genuine Damascus steel blades possess outstanding mechanical properties, often thought superior to modern steels. This idea was shown to be incorrect as long ago as 1924. A famous Swiss collector, Henri Moser, donated 4 genuine Damascus steel swords, one with a non typical carbon content and microstructure, to B. Zschokke, who performed extensive careful experiments including metallographic and chemical analysis in addition to mechanical testing. A series of bending tests compared samples from the swords to a pattern welded blade and a cast blade from the famous German knife center in Solingen. The 3 good Damascus blades showed significantly inferior bending deflection prior to breakage than the 2 Solingen blades in spite of the fact that the Brinell hardness of the 3 ranged from only 193 to 248, compared to 347 and 463 for the pattern welded and cast Solingen blade, respectively. This is not too surprising in view of the now well known fact that toughness of high carbon steels is inherently low; the Solingen blades had carbon levels of 0.5 to 0.6% compared to 1.3 to 1.9% for the 3 Damascus blades. The reputation of Damascus steel blades being superior to European blades was probably established prior to the 17th century when European blades were still being made by forge welding of carburized iron. It is hard to avoid embrittlement of such blades due to imperfect welding during the forging process as well as difficulty with the carburizing process.
Damascus blades: sharp... yes, but brittle.

17th August 2021, 09:44 PM	#16
urbanspaceman Member Join Date: Sep 2017 Location: Tyneside. North-East England Posts: 522	Wootz It was vital that the correct leaves and twigs were added to the crucible when making Wootz. Just adding charcoal/carbon didn't do it as there needed to be trace elements of Molybdemum, Vanadium and Chromium along with nanowires of cementite. What is produced is a hypereutectoid steel which is hard, high carbon steel that remains malleable. Contention exists over whether Wootz blades were quenched at all. It has been suggested that: "if high carbon Wootz is heated to the extent that a substantial amount of the carbides are dissolved, then upon quenching and tempering its microstructure would turn into a proverbial dog's breakfast with very uncertain mechanical properties". Dr. John Verhoeven continues: There is a general myth in some of the popular literature that genuine Damascus steel blades possess outstanding mechanical properties, often thought superior to modern steels. This idea was shown to be incorrect as long ago as 1924. A famous Swiss collector, Henri Moser, donated 4 genuine Damascus steel swords, one with a non typical carbon content and microstructure, to B. Zschokke, who performed extensive careful experiments including metallographic and chemical analysis in addition to mechanical testing. A series of bending tests compared samples from the swords to a pattern welded blade and a cast blade from the famous German knife center in Solingen. The 3 good Damascus blades showed significantly inferior bending deflection prior to breakage than the 2 Solingen blades in spite of the fact that the Brinell hardness of the 3 ranged from only 193 to 248, compared to 347 and 463 for the pattern welded and cast Solingen blade, respectively. This is not too surprising in view of the now well known fact that toughness of high carbon steels is inherently low; the Solingen blades had carbon levels of 0.5 to 0.6% compared to 1.3 to 1.9% for the 3 Damascus blades. The reputation of Damascus steel blades being superior to European blades was probably established prior to the 17th century when European blades were still being made by forge welding of carburized iron. It is hard to avoid embrittlement of such blades due to imperfect welding during the forging process as well as difficulty with the carburizing process. Damascus blades: sharp... yes, but brittle.