For those interested, here's a link to one of the article regarding the Titanic steel study...even with pictures of inclusions and stuff smile
http://www.tms.org/pubs/journals/jom/9801/felkins-9801.html

William knows perfectly well that impurities & inclusions in steel matter, and to argue otherwise is just silly.

The proper amount of non-ferrous elements can be a good thing however. Silicon and phosphorus can increase strength. Sulfur increases machinability (416-R stainless is resulfurized). Manganese can prevent iron sulfide and inclusions; in the correct amount and ratio.