Here is an old thread that discusses the technological and metallurgical issues that came into play with old heirloom swords, which at times would encourage and other times discourage them from being passed down through the generations. Featuring comments from /u/alriclofgar, /u/A_Soporific, and myself.

Follow up: would a sword need regular sharpening and honing? Kitchen knives are often seen worn thin from being used everyday and sharpened repeatedly, whereas I was under the impression that most of a soldier's life was spent marching, sieging, looting, etc. Would a soldier actually have to stab people that often in his life that it warranted the destruction of his blade from over-sharpening? Or would a sword spend most of its life oiled in a scabbard?