Yes, but...
Yes, It it a type of steel. But in its raw form, it is unuasable crap. It has to be forgewelded and folded several times before it becomes good steel. The folding process always goes with the tamahagane. The folding itself can leave folding scars, which are basically lengthwise inclusions. And the folding also leaves a pattern of faint lines also running lengthwise.
EDIT: I notice that Mike already wrote the same, thing, only more comprehensive
