Is it true that the Imperial Japaneese Navys armour war made out of inferior steel?

by Albino-Bob

I read somewhere on the internet while reading an article about Yamatos sistership being used for target practice for the Iowa class 16inch.

I cannot remember where i saw it but i believe that the impurities of the steel made it only 85% effective compared to US Navys battleplate.

Edit: I found where i read it before, does anyone has more information about this.

http://pwencycl.kgbudge.com/A/r/Armor.htm

ParkSungJun

Japanese steel was quite poor both qualitatively and quantitatively, but none of the Yamato class battleships ever encountered a US battleship, let alone the Iowa-class battleships.