Crucible steel blades

Jens Nordlunde · 8th October 2006, 03:06 PM

Robert Hoyland and Brian Gilmour quotes in the book ‘Medieval Islamic Swords and Swordmaking’ al-Biruni who lived in the 10th century. On page 168 the swords of the Rus or Vikings are described. “…. These swords are described as composite blades with edges of hard, or male, iron (shaburqan), which we know from Kindi’s definition means, at least in this case, directly smelted or bloomery steel. Biruni reports that these swords had a central pattern welded part forming a wide channel or fuller, running down the blade, made of soft iron (narmahan). This composite design ensured that the blades would be tough and able to withstand being struck, unlike those made of crucible steel (fuladh), which he says were prone to snap in the extreme cold of the Russian winters. The very high carbon content of the crucible steel used to make the blades was no doubt the reason. The problem of steel being prone to brittle stress failure in cold weather has been encountered more recently, and the effect is now known to increase with carbon content.
(note: See Reed-Hill, Physical Metallurgy Principles, 783-786).

Can anyone explain why more carbon in the steel will make it more brittle in cold weather, and how far north did they use crucible steel for blades?

8th October 2006, 03:06 PM	#1
Jens Nordlunde Member Join Date: Dec 2004 Location: Europe Posts: 2,718	Crucible steel blades Robert Hoyland and Brian Gilmour quotes in the book ‘Medieval Islamic Swords and Swordmaking’ al-Biruni who lived in the 10th century. On page 168 the swords of the Rus or Vikings are described. “…. These swords are described as composite blades with edges of hard, or male, iron (shaburqan), which we know from Kindi’s definition means, at least in this case, directly smelted or bloomery steel. Biruni reports that these swords had a central pattern welded part forming a wide channel or fuller, running down the blade, made of soft iron (narmahan). This composite design ensured that the blades would be tough and able to withstand being struck, unlike those made of crucible steel (fuladh), which he says were prone to snap in the extreme cold of the Russian winters. The very high carbon content of the crucible steel used to make the blades was no doubt the reason. The problem of steel being prone to brittle stress failure in cold weather has been encountered more recently, and the effect is now known to increase with carbon content. (note: See Reed-Hill, Physical Metallurgy Principles, 783-786). Can anyone explain why more carbon in the steel will make it more brittle in cold weather, and how far north did they use crucible steel for blades?