The Iron Man is not really made out of iron scientifically. How do we know that he isn't really made out of iron?
Well being that this is a comic book character rules out real life issues with design. Iron Man was first seen in 1963 and his first suit was Iron but in Steel form giving it the grey color it had. Steel was the only product he had to use due to his imprisonment. Later on in the series you get the common red-and-golden weapon platform which was more than likely not made of steel.
