it is a yataghan
http://forums.taleworlds.com/index.php/topic,162123.0.html

and no it would not be able to cut thru metal armour, however it would have a good go at getting thru leather armour, it can carve thru bricks ok without any apparent dulling to the edge, it can also poke into bricks without any dulling of the point, it would smash the replica katanas that they sell in high street shops (I dont mess with it nowadays, dont want my sons getting ideas, ive stopped practicing with it since I got married i practiced with it for about 20 years before that on and off, never needed any serious resharpening)