Hi
there are some good articles out there on brittle fracture..
http://www.key-to-steel.com/default....Article&NM=136
and some of the elements that affect it
just my opinion... but i think that swords were rather effective close combat sidearms....   ( spear being no. 1 )    ....  
- there has to be some value to it..... or why would so many cultures value such a costly item...  ( you can make many spears out of one sword ) ...   besides, iron production back then was very small scale compared to today... so your limited interms of materials to which you can use for war..
-- even the northlands valued the sword..   as is evidenced by the viking blades...  and the complex patternwelds
- are there any Rc tests done on viking blades...    
- from the few museum curators that i emailed ... (Longtime ago)   they mentioned that the northern swords had a lower Rc ....somewhere round 40
- but i've never seen those stat's anywhere
steel is such a complicated thing....  uggh
Greg