I've heard a great deal on how horribly poor the quality of native Japanese steel is, I beleive it's called something along the lines of Tamahamange (excuse the conjecture.)
I suggest bringing this question to the
MyArmoury Forum. The users are knowledgeable, and more importantly, honest.
You may want to note that a good ammount of high end modern Katana reproductions use Swedish Powder Steel. And take another note that Japanese Shoguns imported their armour from Europe. But I'm sure you'll hear a different (fabricated) story on a Samurai/Japanese Martial Arts forum.
And the Western Industrial Revolution had more to do with the mass production of steel, rather than the quality of it.