L6 is commonly known as saw steel because it is used for the making of saws, large and small. It is a simple tool steel. I have a small utility knife in L6. It is very tough, and holds an edge extraordinarily well. It seems a little harder to sharpen than O1, W2, or 5160 steels, but that may just be the heat treat on this particular knife.
L6 has No real rust resistance. Treat it like any other carbon steel: oil, wax, or tuffcloth is required. Great steel.
From Joe Talmadge's STEEL FAQ here on this site:
L6
A band saw steel that is very tough and holds an edge well, but rusts easily. It is, like O-1, a forgiving steel for the forger. If you're willing to put up with the maintenance,this may be one of the very best steels available for cutlery, especially where toughness is desired.
Hope this helps,
Paracelsus