This might be of interest for those who like the more technical side of sword making:

OSAKA -- Hydrogen is now considered a precious clean energy source, but has long been thought a cause of metals becoming weaker and brittle. In 2010, researchers at Kyushu University and the National Institute of Advanced Industrial Science and Technology discovered that adding a supersaturated level of the colorless, odorless gas into a metal made it stronger. The result ran counter to conventional wisdom. However, has this finding led researchers around the world to change their view of hydrogen's impact on metals?

http://asia.nikkei.com/magazine/20140626-Nest...then-steel

Sword blades to be made from hydrogen-strengthened steel? Well, let's hope that one day blacksmiths produce swords from that kind of steel. ;)